bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of AlN nucleation layers for AlGaN/GaN heterostructures on 4H‐SiC
Authors: Boeykens S. , Leys M. R. , Germain M. , Cheng K. , Derluyn J. , Van Daele B. , Van Tendeloo G. , Belmans R. , Borghs G.
Published: May 2006

Growth of GaN on AlN nucleation layers (NL) by LP‐MOVPE on 4H‐SiC substrates is investigated in order to obtain high quality GaN layers for AlGaN/GaN HEMTs. The relationship between structural quality, surface morphology and electrical properties has been investigated using HR‐XRD, AFM, TEM, Van der Pauw‐Hall and TLM measurements. It is shown that there is a correlation between AlN NL strain and HEMT 2DEG properties. Optimum layers show a Hall sheet resistance of 250 Ω/sq. Finally, HEMT transistors have been processed and measured, showing a saturated drain current of 1.2 A/mm for a gate length of 1.5 μm. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Membrane structures containing InGaN/GaN quantum wells fabricated by wet etching of sacrificial silicon substrates
Authors: Park S.‐H. , Liu C. , Gu E. , Dawson M. D. , Watson I. M. , Bejtka K. , Edwards P. R. , Martin R. W.
Published: May 2006

InGaN/GaN multiple quantum wells (MQWs) emitting at 410‐505 nm, with either 3 or 16 repeat periods, were grown on commercial GaN‐on‐silicon templates using metal organic vapour phase epitaxy. Spectroscopic and structural studies confirmed these MQWs are of similar quality to analogues grown on sapphire substrates. Wet etching of the silicon (111) substrates in HF‐based solutions allowed the MQW structures to be converted into membranes up to 2 mm in diameter, suspended above macroscopic via holes. Such a fabrication step is attractive for the production of microcavities, and other forms of surface emitting laser. Several MQWs have been compared by photoluminescence and cathodoluminescence spectroscopy before and after conversion to membranes. These measurements indicated a consistent increase in luminescence intensity after substrate removal, accompanied by small redshifts in peak position. We have further demonstrated plasma etching of membrane structures from the underside, as will be used to optimise structures for optical pumping, and used atomic force microscopy to monitor associated changes in surface roughness. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photocapacitance characteristics of (In,Ga)N/GaN MQW structures
Authors: Rivera C. , Pau J. L. , Muñoz E. , Ive T. , Brandt O.
Published: May 2006

Photocapacitance techniques have been used to study the electronic properties of (In,Ga)N/GaN quantum wells (QWs). Negative differential capacitance (NDC) features were observed at room temperature for the first time in capacitance‐voltage (C‐V) experiments under optical excitation. A detailed analysis of the results seems to indicate that charge accumulation in quantum dot‐like structures embedded in the QWs could be responsible of such behaviour. Polarization field effects present in these structures are detected through C‐V hysteresis, allowing to estimate built‐in electric fields as high as 1.9 MV/cm in 14% In QWs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of wavelength shifts of green and blue light emitting diodes with InN/GaN multiple quantum wells
Authors: Kim Je Won , Lee Kyu Han , Hong Sangsu
Published: May 2006

InN/GaN multiple quantum wells were grown by metalorganic chemical vapor deposition. The structural and electrical properties were characterized by transmission electron microscopy and electroluminescence measurements. From the transmission electron micrographs, it was shown that the well layer was grown like a quantum dot. The well layer is expected to be the nano‐size structures in the InN multiple quantum well layers. The multi‐photon confocal laser scanning microscopy was used to investigate the optical properties of the light emitting diode structures with InN active layers. It was found that the two‐photon excitation was possible in InN system. The pit density was measured by using the far‐field optical technique. In the varied current conditions, the blue light emitting diode with the InN multiple quantum well structures did not have the wavelength shift. With this result, we can expect that the white light emitting diodes with the InN multiple quantum well structures do not show the color temperature changes with the variations of applied currents. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural analysis of pyramidal defects in Mg‐doped GaN
Authors: Pretorius A. , Schowalter M. , Daneu N. , Kröger R. , Rečnik A. , Rosenauer A.
Published: May 2006

Pyramidal defects in GaN:Mg grown by metalorganic vapour phase epitaxy are studied by high resolution transmission electron microscopy, energy dispersive X‐ray analysis and scanning transmission electron microscopy. High resolution transmission electron microscopy images were simulated using the multislice approach in order to analyse the basal plane of the pyramidal defects. The simulated images were compared quantitatively with the experimental images. Two structural models for the basal plane inversion domain boundary containing antibixbyite‐type layers are presented which show the best observed agreement with the experimentally found inversion domain boundary. Nevertheless, both models still do not match the experimental images satisfactorily, indicating that some other structure than antibixbyite is present at the boundary. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The initial growth stage in PVT growth of aluminum nitride
Authors: Heimann P. , Epelbaum B. M. , Bickermann M. , Nagata S. , Winnacker A.
Published: May 2006

The main issue in homoepitaxial growth of aluminum nitride (AlN) on native seed substrates is the formation of an aluminum oxynitride (AlON) layer at temperatures between 1850‐1950 °C leading to polycrystalline growth. On the contrary, heteroepitaxial growth of AlN on silicon carbide (SiC) is relatively easy to achieve due to natural formation of a thin molten layer of (Al2OCx) on the seed surface and consequent growth of AlN via the molten buffer layer. Optimization of the seeding process can be achieved by use of ultra‐pure starting material. Another critical issue of AlN growth on SiC is cracking of the grown layer upon cooling as a result of different thermal expansion coefficients. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier dynamics of optical emission from two‐dimensional electron gas in undoped AlGaN/GaN single heterojunctions
Authors: Kwack H. S. , Cho Y. H. , Kim G. H. , Park M. R. , Youn D. H. , Bae S. B. , Lee K.‐S. , Lee J. H. , Lee J. H.
Published: May 2006

The strucutral and optical properties of undoped AlGaN/GaN single heterojunctions (HJs) were studied by means of high‐resolution x‐ray diffraction, photoluminescence (PL), cathodoluminescence (CL), and time‐resolved PL spectroscopy. An additional two‐dimensional electron gas (2DEG)‐related PL and CL emission appeared at about 40 meV below the GaN band‐edge emission energy and persisted up to about 100 K, while this peak disappeared when the top AlGaN layer was removed by reactive ion etching. Depth‐resolved CL spectra reveal the presence of a 2DEG at the heterointerface. The additional PL and CL emission below the GaN band‐edge emission is attributed to the recombination between photogenerated holes and electrons confined at 2DEG states in the triangular‐shaped interface potential. For the 2DEG emission, we observed an about 50‐ps delayed rise time than the GaN and AlGaN emissions by using time‐resolved PL, indicating effective carrier transfer from the GaN flatband and AlGaN regions to the heterointerface. From the results, we explained the optical properties and carrier recombination dynamics of 2DEG, GaN, and AlGaN emissions in undoped AlGaN/GaN single HJs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Localization of non‐equilibrium carriers in deep InGaN quantum dots and its impact on the device performance
Authors: Sizov D. S. , Sizov V. S. , Lundin V. V. , Zavarin E. E. , Tsatsul'nikov A. F. , Vlasov A. S. , Musikhin Yu. G. , Ledentsov N. N. , Mintairov A.M. , Sun K. , Merz J.
Published: May 2006

Structural and optical properties of MOCVD grown InGaN quantum dot (QD) layers have been studied using transmission electron microscopy, X‐ray diffraction, near‐field spectroscopy and selectively excited photoluminescence. We have shown that the presence of Indium in the matrix strongly increases the activation energy of QD layers, due to stimulated phase separation. The increase of the activation energy is accompanied by an increase of the activation time, which was revealed from photocurrent spectroscopy. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Active‐controlled, non‐inferiority trials in oncology: arbitrary limits, infeasible sample sizes and uninformative data analysis. Is there another way?
Authors: Carroll Kevin J.
Published: May 2006

In oncology, it may not always be possible to evaluate the efficacy of new medicines in placebo‐controlled trials. Furthermore, while some newer, biologically targeted anti‐cancer treatments may be expected to deliver therapeutic benefit in terms of better tolerability or improved symptom control, they may not always be expected to provide increased efficacy relative to existing therapies. This naturally leads to the use of active‐control, non‐inferiority trials to evaluate such treatments. In recent evaluations of anti‐cancer treatments, the non‐inferiority margin has often been defined in terms of demonstrating that at least 50% of the active control effect has been retained by the new drug using methods such as those described by Rothmann et al., Statistics in Medicine 2003; 22:239–264 and Wang and Hung Controlled Clinical Trials 2003; 24:147–155. However, this approach can lead to prohibitively large clinical trials and results in a tendency to dichotomize trial outcome as either ‘success’ or ‘failure’ and thus oversimplifies interpretation. With relatively modest modification, these methods can be used to define a stepwise approach to design and analysis. In the first design step, the trial is sized to show indirectly that the new drug would have beaten placebo; in the second analysis step, the probability that the new drug is superior to placebo is assessed and, if sufficiently high in the third and final step, the relative efficacy of the new drug to control is assessed on a continuum of effect retention via an ‘effect retention likelihood plot’. This stepwise approach is likely to provide a more complete assessment of relative efficacy so that the value of new treatments can be better judged. Copyright © 2006 John Wiley & Sons, Ltd.
Pharmacological activity of three commercial Hypericum perforatum preparations in mice
Authors: Jean D. , Pouligon M. , Henriot A. C.
Published: May 2006

St John's Wort (Hypericum perforatum) is the main herbal species used to treat depression. The products available on the pharmaceutical and dietary supplement markets are obtained by a variety of preparation processes and their pharmacological effects may differ significantly. The purpose of this study therefore was to investigate the effect of different St John's Wort commercial preparations available on the French market. Only one preparation gave significant results in the forced swimming test. Copyright © 2006 John Wiley & Sons, Ltd.
Bulk agent Plantago ovata after Milligan‐Morgan hemorrhoidectomy with Ligasure™
Authors: Kecmanovic Dragutin M. , Pavlov Maja J. , Ceranic Miljan S. , Kerkez Mirko D. , Rankovic Vitomir I. , Masirevic Vesna P.
Published: May 2006

The aim of this study was to determine usefulness of the bulk agent Plantago ovata in reducing postoperative pain and tenesmus after open hemorrhoidectomy (Milligan‐Morgan with Ligasure™). Ninety‐eight patients were randomized into two groups of 49 patients each. In both groups Milligan‐Morgan open hemorrhoidectomy with Ligasure™ was performed. The first group received postoperatively two sachets daily of 3.26 g of the bulk agent, Plantago ovata, for 20 days. The control group was treated postoperatively with glycerin oil. There was no statistically significant difference in age, gender distribution and hemorrhoid grading, between the two groups. The pain score after first defecation (p < 0.001) and after 10 days (p < 0.01) and the global pain score (p < 0.001) was statistically significantly lower in the group treated with Plantago ovata, while there was no statistically significant difference in the pain level after 20 days (p > 0.05). The hospital stay was statistically significantly shorter in the group receiving Plantago ovata (2.6 ± 0.6 vs 3.9 ± 0.7 days, p < 0.001). The incidence of tenesmus was higher in the control group (40.8% vs 10.2%, p < 0.01). Treating patients with Plantago ovata after open hemorrhoidectomy, reduces pain, tenesmus rate and shortens postoperative hospital stay. Copyright © 2006 John Wiley & Sons, Ltd.
Adenovirus: from foe to friend
Authors: Gonçalves Manuel A. F. V. , de Vries Antoine A. F.
Published: May 2006

Human adenoviruses (HAdVs) can cause mild respiratory, gastrointestinal, urogenital and ocular disease. Knowledge about HAdVs has been expanding for more than five decades putting them amongst the most‐studied viruses. This continued interest stems, to a great extent, from the fact that these double‐stranded DNA viruses have proven to be a versatile tool to probe the basic phenomena of eukaryotic cells. HAdV research has led to the discovery of, for instance, RNA splicing and greatly contributed to our knowledge of processes as fundamental as replication, transcription and translation. Moreover, the transformation of rodent cells by HAdVs has provided a system to unravel the molecular pathways that control cell proliferation. As a result, the genetic organisation of these agents is known in great detail allowing the straightforward manipulation of their genomes. In addition, the virus itself became renowned for its ability to produce large amounts of progeny and to efficiently infect mammalian cells regardless of their cell cycle status. These features contributed to the broad use of recombinant HAdVs as gene carriers particularly in in vivo settings where the vast majority of target cells are post‐mitotic. The most advanced type of HAdV vectors can accommodate up to 37 kb of foreign DNA and are devoid of viral genes. With the aid of these high‐capacity HAdV vectors large physiologically responsive transcriptional elements and/or genes can be efficiently introduced into target cells while minimising adaptive immune responses against the transduced cells. This article provides information on HAdV especially on the aspects pertinent to the design, production and performance of its recombinant forms. The development and characteristics of the main HAdV‐based vector types are also briefly reviewed. Copyright © 2006 John Wiley & Sons, Ltd.
Kyasanur forest disease: an epidemiological view in India
Authors: Pattnaik Priyabrata
Published: May 2006

Kyasanur forest disease (KFD) was first recognised as a febrile illness in the Shimoga district of Karnataka state of India. The causative agent, KFD virus (KFDV), is a highly pathogenic member in the family Flaviviridae, producing a haemorrhagic disease in infected human beings. KFD is a zoonotic disease and has so far been localised only in a southern part of India. The exact cause of its emergence in the mid 1950s is not known. A variant of KFDV, characterised serologically and genetically as Alkhurma haemorrhagic fever virus (AHFV), has been recently identified in Saudi Arabia. KFDV and AHFV share 89% sequence homology, suggesting common ancestral origin. Homology modelling of KFDV envelope (E) protein exhibited a structure similar to those of other flaviviruses, suggesting a common mechanism of virus‐cell fusion. The possible mechanism of receptor‐ligand interaction involved in infection by KFDV may resemble that of other flavivirses. Present understanding is that KFDV may be persisting silently in several regions of India and that antigenic and structural differences from other tick borne viruses may be related to the unique host specificity and pathogenicity of KFDV. From January 1999 through January 2005, an increasing number of KFD cases have been detected in Karnataka state of Indian subcontinent despite routine vaccination, suggesting insufficient efficacy of the current vaccine protocol. However, the exact cause of the increase of KFD cases needs further investigation. Considering the requirement of safer and more effective vaccines in general, there is clearly a need for developing an alternative vaccine as well as a rapid diagnostic system for KFD. The changing ecology of the prime focus of the KFD also warrants attention, as it may lead to establishment of the disease in newer localities, never reported before. Copyright © 2006 John Wiley & Sons, Ltd.
The influence of fetal position on amniotic fluid index and single deepest pocket
Authors: Fok W. Y. , Chan L. Y. , Lau T. K.
Published: May 2006

Objective

To evaluate the effect of fetal position on measurement of amniotic fluid index (AFI) and of the single deepest pocket (SDP).

Methods

This was a prospective observational study, in a university obstetric unit, of women with an uncomplicated singleton pregnancy with longitudinal lie and cephalic presentation at or beyond 28 weeks of gestation. AFI was calculated and SDP measured and the fetal position was characterized in terms of three parameters. These were: the side of the maternal abdomen on which the fetus lay; a numerical representation (laterality score) of the distance that the fetus was from the sagittal midline plane of the maternal abdomen; the orientation of the fetal trunk (ventral anterior, lateral or posterior).

Results

Eighty‐one women were recruited into the study. There was a significant relationship between the laterality score and the AFI (P = 0.005) but not the SDP (P = 0.23): AFI was on average 4.35 cm higher in fetuses lying centrally compared with those lying laterally inside the uterus. There was no significant difference for either SDP (P = 0.8) or AFI (P = 0.3) between fetuses lying on the right or the left side of the maternal abdomen. Similarly, there was no significant difference in SDP (P = 0.9) or AFI (P = 1.0) for the different orientations of the fetal trunk.

Conclusion

Fetal position affects the measurement of AFI but not that of SDP. Therefore, SDP may be a more consistent parameter for the estimation of amniotic fluid volume. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Model estimated uncertainties in the calibration of a total reflection x‐ray fluorescence spectrometer using single‐element standards
Authors: Owoade O. K. , Olise F. S. , Olaniyi H. B. , Wegrzynek D.
Published: May 2006

Total reflection x‐ray fluorescence (TXRF) was used for the analysis of single‐element standards, Ca, Cr, Zn, Ga, Se, Rb, Sr and Y, at various concentrations. A triplicate analysis was carried out to determine the homogeneity of the samples and the reproducibility of the results. The average estimated uncertainty (model calculated) values was compared with the predicted uncertainties (systematic or equipment related). The estimated and the predicted uncertainties showed considerable agreement except at very low concentrations resulting from excessive dilution. The discrepancies decreased as the concentrations of the analytes increased. This work indicates a very reliable dependence on the systematic or predicted uncertainties from TXRF spectrometric analysis, especially at high concentrations. Copyright © 2006 John Wiley & Sons, Ltd.
Mak16p is required for the maturation of 25S and 5.8S rRNAs in the yeast Saccharomyces cerevisiae
Authors: Pellett Sabine , Tracy James W.
Published: May 2006

The nucleolar Mak16p protein of Saccharomyces cerevisiae has been implicated in 60S ribosome biogenesis. To learn more about the role of Mak16p in this process, ribosomal RNA processing was examined in a mak16‐1 temperature‐sensitive yeast strain. Steady‐state levels of the 25S and 5.8S mature rRNA species dropped dramatically over a 4 h period in the mak16‐1 yeast after a shift to the non‐permissive temperature, while 18S and 5S rRNA levels decreased only moderately. Ribosomal RNA processing (rRNA) analyses showed that the most prominent defect at the non‐permissive temperature was a dramatic decrease in 27SB precursor RNA levels, with no significant increase in the levels of any precursor. These data indicate an essential role for Mak16p in the stability of the 27SB precursor rRNA. Association of Mak16p with the 66S preribosomal complex does not appear to be sufficient for its function, because the mutant Mak16‐1p protein was detected in sucrose density gradient fractions corresponding to the 66S pre‐RNP complex. Copyright © 2006 John Wiley & Sons, Ltd.
Near‐infrared spectroscopic monitoring of biomass, glucose, ethanol and protein content in a high cell density baker's yeast fed‐batch bioprocess
Authors: Finn Beverley , Harvey Linda M. , McNeil Brian
Published: May 2006

The use of at‐line NIRS to monitor a high cell density fed‐batch baker's yeast bioprocess was investigated. Quantification of the key analytes (biomass, ethanol and glucose) and the product quality indicator (percentage protein content) was studied. Biomass was quantitatively modelled using whole matrix samples (as was percentage protein content). The dominance of the whole matrix spectrum by biomass, and its associated light scattering effects, were overcome by use of filtrate samples and adapted (semi‐synthetic) filtrate samples, which allowed successful ethanol and glucose modelling, respectively. Calibrations were rigorously challenged via external validation with large sample sets relative to the calibration sample size, ensuring model robustness and potential practical utility. The standard errors of calibration for biomass, glucose, ethanol and total intracellular protein were (g/l) 1.79, 0.19, 0.79 and 0.91, respectively, comparable to those of the primary assays. The calibration strategies necessary to generate quantitative models for this range of analytes in such a complex high cell density bioprocess fluid are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Repression of CDC28 reduces the expression of the morphology‐related transcription factors, Efg1p, Nrg1p, Rbf1p, Rim101p, Fkh2p and Tec1p and induces cell elongation in Candida albicans
Authors: Umeyama Takashi , Kaneko Aki , Niimi Masakazu , Uehara Yoshimasa
Published: May 2006

The ability of the human fungal pathogen Candida albicans to transit its cell shape is important for its pathogenicity. To obtain additional evidence that the cell cycle of C. albicans is associated with its morphology, we generated and characterized a conditional mutant of C. albicans CDC28, a cyclin‐dependent kinase. In the constructed strain, the expression of CDC28 was regulated by the MET3 promoter and could be repressed in the presence of methionine and cysteine. Cdc28p‐depleted cells demonstrated highly polarized growth and wider filaments than serum‐induced hyphae. Hyphae‐specific genes, HWP1, RBT4 and ECE1, were activated in the elongated filaments caused by the Cdc28p depletion. Furthermore, the protein expression levels of the transcription factors involved in morphological transition, Efg1p, Nrg1p, Rbf1p, Rim101p, Fkh2p and Tec1p, decreased under conditions that repress CDC28 expression. Taken together, these data indicate that repression of CDC28 affected the protein levels of the morphology‐related transcription factors, the regulation of hyphae‐specific genes and cell shape in C. albicans. Copyright © 2006 John Wiley & Sons, Ltd.
Annotation of unknown yeast ORFs by correlation analysis of microarray data and extensive literature searches
Authors: Pir Pınar , Ülgen Kutlu Ö. , Hayes Andrew , İlsen Önsan Z. , Kırdar Betül , Oliver Stephen G.
Published: May 2006

Changes in the expression of genes were used to elucidate the metabolic pathways and regulatory mechanisms that respond to environmental or genetic modifications. Results from previously published chemostat datasets were merged with novel data generated in the present study. ORFs displaying significant changes in expression that correlated with those of other ORFs were analysed using GO mapping tools and supplemented by literature information. The strategy developed was used to propose annotations for ORFs of unknown function. The following ORFs were assigned functions as a result of this study: YMR090w, YGL157w, YGR243w, YLR327c, YER121w, YFR017c, YGR067c, YKL187c, YGR236c (SPG1), YMR107w (SPG4), YMR206w, YER067w, YJL103c, YNL175C (NOP13) YJL200C, YDL070C (FMP16) and YGR173W. Copyright © 2006 John Wiley & Sons, Ltd.
Education of the Modern Surgical Resident: Novel Approaches to Learning in the Era of the 80‐Hour Workweek
Authors: Nguyen Liz , Brunicardi F. Charles , DiBardino Daniel J. , Scott Bradford G. , Awad Samir S. , Bush Ruth L. , Brandt Mary L.
Published: May 2006

Introduction

Implementation of the 80‐hour work week has resulted in limitations on the hours available for resident education, creating a need for innovative approaches to teach surgical residents successfully. Herein we report the methods and results of an innovative didactic learning program at a large academic surgerical residency program.

Methods

Between 2004 and 2005, based on known principles of adult education and innovative learning techniques, a didactic learning program was instituted in a major academic surgery program. The course work consisted of a structured reading program using Schwartz’s Textbook of Surgery, with weekly testing and problem‐based learning (PBL) groups led by surgical faculty. The residents’ progress was assessed by American Board of Surgery In‐Training Examination (ABSITE) training scores before and after program implementation. A resident survey was also conduced to assess residents’ attitudes toward the new program. Results were reported as a mean, and categoric variables were compared using a paired Student’s t‐test.

Results

During the academic year of the structured reading program, the mean ABSITE score improved by 10% (P = 0.02) from the previous year. The postgraduate year 4 class had the largest change, with a score increase of 17% over the previous year’s performance (P = 0.02). Survey results demonstrated that 64% of the responders agreed that the small‐group PBL was preferable for achieving educational goals. Furthermore, 89% of residents responded that the PBL groups improved interaction between residents and faculty members.

Conclusions

An innovative formal learning program based on a major surgical textbook with weekly testing and small group sessions can significantly improve surgical training in the modern era of work‐hour restrictions. Furthermore, surgical trainees find this format to be innovative and useful for improving didactic teaching.
Telemedicine and Electronic Health Information for Clinical Continuity in a Mobile Surgery Program
Authors: Mora Francisco , Cone Stephen , Rodas Edgar , Merrell Ronald C.
Published: May 2006

Introduction

An intermittent surgical services program in rural Ecuador was able to benefit from close collaboration between surgeons and primary care physicians through the use of telemedicine technologies.

Methods

Inexpensive telemedicine workstations capable of patient documentation, imaging, and video‐conferencing at extremely low bandwidth were established in collaborative primary care sites in rural Ecuador. Patients were screened for intermittent surgical services by primary caregivers according to the surgeons’ guidelines. Real‐time and store‐and‐forward telemedicine allowed appropriate collaborative, informed decision‐making. Surgery was performed, and postoperative care was similarly handled by on‐site, familiar primary caregivers.

Results

To date, this system has been used in more than 124 patient encounters (74 preoperative and 50 postoperative visits). The system allowed advance screening of patients on the part of the surgeons, leading to cancellations for 9 patients. Postoperatively, the system allowed 100% concurrence in postoperative diagnoses between the primary caregivers and the surgeons.

Conclusions

Inexpensive, low‐bandwidth telemedicine solutions can support intermittent surgical services by providing patients to have contact with specialist care through their familiar, local primary caregivers.
A New Technique in Closure of Burst Abdomen: TI, TIE and TIES Incisions
Authors: Esmat M. Emad
Published: May 2006

Background

Burst abdomen is a continuing problem for the general surgeon as the incidence of such complication may reach 3% with a mortality rate exceeding 25%.

Methods

New technique: A lateral incision is done from inside the abdomen along a line between the costal margin above to the iliac crest below in the area between the mid and anterior axillary line. According to the depth of the incision, the incision may either involve the transversus abdominus and internal oblique muscles (TI incision), or include in addition the external oblique muscle (TIE incision), or it may also involve the Scarpa’s fascia (TIES incision). Such incisions would give an extra length on each side towards medial advancement. Eight patients, 5 men and 3 women aged 34–67 years, with burst abdomen after major gastrointestinal and hepatobiliary surgery failed to close primarily were managed using this technique. Long‐term follow‐up patients was done for development of complications. Electromyogram (EMG) for the rectus muscle and sensory loss for the abdominal wall were also tested. The distance between the 2 cut edges of the different release incisions was measured clinically (TIES incisions) or using ultrasound device (TI and TIE incisions). Scarpa’s fascia biopsy was taken from 1 patient of the TIE group for histopathological study 6 years after surgery.

Results

One patient died on the third postoperative day (mortality 12.5%), and 2 patients developed subincisional abscesses (25%). No single case of reburst occurred. Long‐term follow‐up showed no single case of incisional hernia in the site of the midline surgical incision, but incisional hernia did occur in all the sites of TIES incisions. Incisional hernia did not occur in the TI incision and, more strangely, neither did it occur in any of the TIE incisions. Follow‐up of the incisions width showed a significant increase in width of the TIES with time while there was no significant increase in that of the TI or TIE. There was a sensory loss at and below the level of umbilicus in the TIES group. EMG showed evidence of motor affection to the rectus muscle at and below the level of the umbilicus in all groups. Scarpa’s fascia biopsy was taken to try to find an explanation for the absence of incisional hernia in TIE incisions and was found to be 3 times as thick and the type I collagen was replaced by collagen type III.

Conclusion

The new method described is simple, straightforward and tension free, with a comparable mortality and morbidity. The Scarpa’s fascia adaptation and its ability to change have enormous applications in general and reconstructive surgery, but further evaluation of such phenomenon is needed.
Clinicopathological Characteristics and Long‐term Outcome in Patients with Distant Metastases from Differentiated Thyroid Cancer
Authors: Benbassat Carlos A. , Mechlis‐Frish Sara , Hirsch Dania
Published: May 2006

Background

Distant metastases are seen in a minority of patients with differentiated thyroid carcinoma (DTC) but account for most of its disease‐specific mortality. Studies on the long‐term outcome of patients with distant metastases are controversial.

Materials and Methods

We retrospectively reviewed the medical records of 660 patients with differentiated thyroid carcinoma followed at our institution from 1994 to 2004. Forty‐four patients (6.7%) had distant metastases, with a prevalence of 4.8% for papillary thyroid cancer, 21% for follicular thyroid cancer, and 10% for Hurthle cell cancer. Primary near‐total thyroidectomy followed by I131 radiation was performed in 97% of patients with metastases (86% operated on in 1980–2003). Mean age at thyroidectomy was 49 ± 19 years, and the female‐to‐male ratio was 1.9:1.

Results

The distant metastasis occurred synchronously with the primary tumor in 45.5% and after a median follow‐up of 9 years in the others. Affected sites were lungs (n = 24), bones (n = 11), lungs and bones (n = 9), brain (n = 3), and uterus (n = 1). Median duration of follow‐up was 12 years (range: 1–42 years) from thyroidectomy and 5.5 years (range: 1–24 years) from diagnosis of distant metastases. The 5‐ and 10‐year survival rates (all causes) after diagnosis of distant metastases were 88% and 77%, respectively. No significant differences in survival curves were found by age, sex, metastasis site, histopathology, or interval to distant metastasis.

Conclusions

We conclude that complete resection of the thyroid gland at diagnosis and high‐dose adjuvant radioactive iodine are associated with improved survival in patients with metastatic DTC.
Hemoglobin‐Based Oxygen Carriers in Trauma Care: Scientific Rationale for the US Multicenter Prehosptial Trial
Authors: Moore Ernest E. , Cheng Aaron M. , Moore Hunter B. , Masuno Tomohiko , Johnson Jeffrey L.
Published: May 2006

Background

The greatest need for blood substitutes worldwide is in patients with unanticipated acute blood loss, and trauma is the most likely scenario. The blood substitutes reaching advanced clinical trials today are red blood cell (RBC) substitutes derived from hemoglobin. The hemoglobin‐based oxygen carriers (HBOCs) tested currently in advanced clinical trials are polymerized hemoglobin solutions.

Methods

In the USA, the standard approach to restoring oxygen delivery for hemorrhagic shock has been crystalloid administration to expand intravascular volume, followed by stored RBCs for critical anemia. Allogeneic RBCs, however, may have adverse immunoinflammatory effects that increase the risk of postinjury multiple organ failure (MOF). Phase II in hospital clinical trials, as well as in vitro and in vivo work, suggest that resuscitation with an HBOC—in lieu of stored RBCs—attenuates the systemic inflammatory response invoked in the pathogenesis of MOF. Specifically, an HBOC has been shown to obviate stored RBC‐provoked polymorphonuclear neutrophil (PMN) priming, endothelial activation, and systemic release of interleukins (IL) 6, 8, and 10. In a 2‐event rodent study of shock‐induced PMN‐mediated acute respiratory distress syndrome (ARDS), the simulated prehospital administration of an HBOC markedly attenuated lung injury.

Results

Based on this background and work by others, we have initiated a US multicenter prehospital trial in which severely injured patients with major blood loss [systolic blood pressure (SBP) ≤90 mmHg] are randomized to initial field resuscitation with crystalloid versus HBOC. During the hospital phase, the control group is further resuscitated with stored RBCs whereas the study group receives HBOC (up to 6 units) in the first 12 hours. The primary study endpoint is decreased 30‐day mortality, and secondary endpoints include reductions in administration of allogeneic RBCs and uncrossmatched RBCs; avoiding circulating hemoglobin levels <5 g/dl; and decreased ARDS and MOF.

Conclusions

To date, >500 injured patients have been enrolled in this multicenter trial, and the final interim analyses support the original target of 720.
Overview of the Essential Trauma Care Project
Authors: Mock Charles , Joshipura Manjul , Goosen Jacques , Maier Ronald
Published: May 2006

The Essential Trauma Care (EsTC) Project represents an effort to set reasonable, affordable, minimum standards for trauma services worldwide and to define the resources necessary to actually provide these services to every injured person, even in the lowest‐income countries. An emphasis is improved organization and planning, at minimal cost. The EsTC Project is a collaborative effort of the World Health Organization and the International Association for Trauma Surgery and Intensive Care, an integrated society within the International Society of Surgery‐Société Internationale de Chirurgie. A milestone of the project has been the release of Guidelines for Essential Trauma Care. This establishes 11 core Essential Trauma Care services that can be considered “The Rights of the Injured.” To assure these services, Guidelines delineates 260 items of human and physical resources that should be in place at the spectrum of health facilities globally. These are delineated in a series of flexible resource tables, to be adjusted based on an individual country’s circumstances. Guidelines is intended to serve as both a planning guide and an advocacy statement. It has been used to catalyze improvements in trauma care in several countries. It has stimulated five national‐level consultation meetings on trauma care, which constituted the highest governmental attention yet devoted to trauma care in those countries. At these meetings, the EsTC resource templates were adjusted to local circumstances and implementation strategies developed. Future efforts need to emphasize more on‐the‐ground implementation in individual countries, greater linkages with prehospital care, and wider political endorsement, such as by passage of a World Health Assembly resolution.
Advancing Essential Trauma Care through the Partner Organizations: IATSIC, ISS‐SIC, and WHO
Authors: Goosen Jacques , Morris Peter , Kobusingye Olive , Mock Charles
Published: May 2006

The publication Guidelines for Essential Trauma Care offers an opportunity to improve trauma care services in an affordable and sustainable fashion, primarily through improved organization and planning. The publication will be useful, however, only if it actually catalyzes improvements in trauma care in health care facilities in individual countries, especially those low‐ and middle‐income countries with the greatest needs. There is much that can be done to make this happen on the part of the partners that created these recommendations, including IATSIC (International Association for Trauma Surgery and Intensive Care); ISS‐SIC (International Society of Surgery–Société Internationale de Chirurgie); and WHO (World Health Organization). This includes such activities as organizing multi‐sectoral stakeholders’ meetings to adapt the Essential Trauma Care (EsTC) criteria to local needs; conducting trauma care needs assessments to identify priorities for low‐cost improvements; having surgical colleges and societies throughout the world endorse the Guidelines; lobbying ministries of health to incorporate the EsTC recommendations into health policy; and seeking to integrate the EsTC recommendations into the 2‐year action plans of WHO country offices. In all of these activities, surgeons and others who care for the injured can play a pivotal role, especially working collaboratively with their own ministries of health and WHO country offices.
Where Do We Belong? Urban Adolescents' Struggle for Place and Voice
Authors: Ross Laurie
Published: May 2006

Through a telling of key events in the history of the “Teen Action Center” (TAC), a drop‐in youth center located in downtown “Unionville,” this story demonstrates how ‘youth’ is an important diversity category. The community conflict highlighted in this story centers around the 1997 arrest of TAC's Executive Director and two youth leaders (all Puerto Rican) because a small group of Latino and African‐American youth was smoking cigarettes on the sidewalk in front of the Center. This conflict brings into focus divergent views on where Unionville's youth of color belong in the city, both physically and figuratively. The lessons learned in this story have wide application as Unionville, and other cities undergoing demographic transformation and economic decline, are likely to continue to experience these types of clashes, where the dominant paradigm of economic development overrides the realities, rights, and interests of marginalized groups.
IL-9 ModulatedMUC4Gene and Glycoprotein Expression in Airway Epithelial Cells
Authors: Damera Gautam , Xia Baoyun , Ancha Hanumatha R. , Sachdev Goverdhan P.
Published: May 2006

Compromised epithelial cell integrity is a common feature associated with chronic lung inflammatory states such as asthma. While epithelial cell damage is largely due to sustained effects of inflammatory mediators localized to airways, the subsequent process of epithelial cell differentiation is attributed to members of the transmembrane receptor tyrosine kinase family called the ErbB's. MUC4, a large molecular weight membrane-bound glycoprotein, has recently been identified as a potential ligand for the ErbB-2 receptor. In this study, we investigated the possible role of interleukin-9 (IL-9), a Th2 cytokine, on MUC4 expression using a lung cancer cell line, NCI-H650. We determined that IL-9 up-regulates MUC4 expression in a time and concentration-dependent fashion. Nuclear run-on assays indicated transcriptional regulation of MUC4 while no post-transcriptional mRNA stabilization was observed by actinomycin D chase experiments. IL-9 also increased MUC4 glycoprotein expression as determined by Western blots using a monoclonal antibody specific for a non-tandem repeat region on ASGP-2 region of MUC4. Furthermore, a JAK3-selective inhibitor 4-(4′-hydroxyphenyl) amino-6, 7-dimethoxyquinazoline (WHI-P131), substantially reduced IL-9-induced MUC4 mRNA expression in a dose-dependent fashion. These results implicate a potential role for IL-9 upon MUC4 expression in human airway epithelial cells.
Deleterious Effects of Supplementation with Dehydroepiandrosterone Sulphate or Dexamethasone on Rat Insulin-Secreting Cells Under In Vitro Culture Condition
Authors: Liu Hui-Kang , Green Brian D. , McClenaghan Neville H. , McCluskey Jannie T. , Flatt Peter R.
Published: May 2006

Dehydroepiandrosterone (DHEA) and glucocorticoids are steroid hormones synthesised in the adrenal cortex. Administration of DHEA, its sulphate derivative, DHEAS, and more controversially dexamethasone (DEX), a synthetic glucocorticoid, have beneficial effects in diabetic animals. Cultivating BRIN-BD11 cells for 3 days with either DHEAS (30 μM) or DEX (100 nM), reduced total cell number and reduced cell viability and cellular insulin content. DHEAS-treated cells had poor glucose responsiveness and regulated insulin release, coupled with reduced basal insulin release. In contrast, DEX-treated cells lacked responsiveness to glucose and membrane depolarisation, and both protein kinase A (PKA) and protein kinase C (PKC) secretory pathways were desensitised. Therefore, we conclude that this steroid hormone and synthetic glucocorticoid are not beneficial to pancreatic β-cells in vitro.
Mannose-6-phosphate/Insulin-like Growth Factor II Receptor Expression and Tumor Development
Authors: Hébert Eric
Published: May 2006

The mannose-6-phosphate/insulin-like growth factor II receptor (M6P/IGF-IIR) is a multi-functional transmembrane glycoprotein whose major function is to bind and transport M6P-bearing glycoproteins from the trans-Golgi network or the cell surface to lysosomes. The cell surface M6P/IGF-IIR also bind and internalizes the insulin-like growth factor II. The receptor gene is considered a « candidate » tumor suppressor gene. The phenotypic consequences of loss of M6P/IGF-IIR through somatic mutation are potentially very complex since M6P/IGF-IIR has a number of roles in cellular physiology. Loss of function mutations in M6P/IGF-IIR gene could contribute to multi-step carcinogenesis. In the light of the multi-functional cellular potential roles of the M6P/IGF-IIR the purpose of this review is to highlight some recent data concerning its normal functions and the potential role of its loss in tumor pathophysiology with the aim to try to clarify the possible underlying mechanisms of its involvement in tumor development.
Phenomenon of Activation of Cytochrome P450 by Nonionic Detergents
Authors: Myasoedova Ksenia N. , Arutyunyan Alexandr M. , Magretova Natalya N.
Published: May 2006

Mechanism of substitution of nonionic detergent Emulgen 913 for phospholipid as an activator of N-demethylase activity of cytochrome P450 form 2B4 (LM2) has been studied. It is shown that such an activation takes place at the detergent concentrations below values critical for micelle formation. Under these conditions, Emulgen does not affect the hexameric state of the cytochrome. The stimulating effect proved to be similar in reconstituted monooxygenase systems containing (a) cytochrome P450 2B4 and NADPH-cytochrome P-450 reductase and (b) cytochrome 2B4 and organic hydroperoxides. These results indicate that the activation is due to an effect of the detergent upon P450 2B4 per se rather than upon P450/flavoprotein complex formation. The above conclusion is supported by the sedimentation data and measurement of the CD spectra of cytochrome P450 2B4 at 380–450 nm.
Antigenic Profile of Osteoblasts Present in Human Bone Tissue Sections
Authors: García-Martínez O. , Reyes-Botella C. , Aguilera-Castillo O. , Vallecillo-Capilla M.F. , Ruiz C.
Published: May 2006

The antigenic profile of human osteoblasts was previously analyzed by our group using primary cultures as study samples. These studies suggested a novel functional approach to this cell population. Osteoblasts have a characteristic antigenic profile and share antigens in common with other cell populations that also originate in the bone marrow. Some of the detected antigens are constitutively expressed, while others are modulated by different factors and/or cytokines. The aim of the present study was to analyze the antigens present in osteoblasts in vivo, since the presence of certain biomolecules in fetal bovine serum may modulate the antigenic expression, compromising the results. For this purpose, human bone tissue sections were analyzed with a wide panel of mAbs and using the immunoperoxidase technique. CD10, CD44 and alkaline phosphatase antigens and IL-12, IL-18 and IFNγ cytokines were detected in osteoblasts in the bone tissue. However, CD80 and HLA-DR antigens were not found in all samples and when present their expression was weak. The expression of CD54 antigen was moderate or weak. These results allow data obtained by the primary culture of osteoblast-like cells to be endorsed.
Cloning and Characterization of a Flavanone 3-Hydroxylase Gene from Ginkgo biloba
Authors: Shen Guoan , Pang Yongzhen , Wu Weisheng , Deng Zhongxiang , Zhao Lingxia , Cao Youfang , Sun Xiaofen , Tang Kexuan
Published: May 2006

Flavanone 3-hydroxylase (F3H) activity is necessary for the biosynthesis of flavonoids, the main ingredients of Gingko biloba extract. The full-length cDNA and genomic DNA sequences of F3H gene were isolated from G. biloba for the first time. The full-length cDNA of G. biloba F3H gene (designated as GbF3H) contained a 1071 bp open reading frame (ORF) encoding a 357-amino-acid protein with a calculated molecular weight of about 40 kDa and isoelectric point (pI) of 5.57. The genomic DNA analysis showed that GbF3H gene had three exons and two introns. The deduced GbF3H protein showed high identities to other plant F3Hs. The conserved amino acids ligating ferrous iron and residues participating in 2-oxoglutarate binding (R-X-S) were found in GbF3H at the similar positions like other F3Hs. Three-dimensional structure modeling showed that GbF3H had a jerry roll in the enzyme core consisted of β-sheet, a typical structure shared by all 2-oxoglutarate-dependent dioxygenases including F3Hs. Phylogenetic tree analysis revealed that GbF3H shared the same ancestor in evolution with other F3Hs and had a further relationship with other angiosperms species. Southern blot analysis indicated that GbF3H belonged to a multi-gene family. Transcription analysis revealed that GbF3H expressed in stem and leaf with the highest transcription level in leaf. The isolation and characterization of GbF3H gene will be helpful to further study the role of GbF3H gene in the biosynthesis of flavonoids in G. biloba.