ESRF

Distribution by Scientific Domains


Selected Abstracts


In situ Grazing Incidence Scattering Investigations During Magnetron Sputtering Deposition of FePt/Ag Thin Films (Adv. Eng.

ADVANCED ENGINEERING MATERIALS, Issue 6 2009
Mater.
The cover picture shows an grazing incidence small angle X-ray scattering pattern of a granular Ag(6nm)-FePt(7.5nm)-Ag-FePt thin film using an in-situ magnetron sputtering chamber measured directly after growth at the Beamline BM20 (ROBL) at the ESRF. The sequential deposition provides separated, faceted FePt nanoislands without any magnetic property degradation and with magnetic moments preferentially oriented parallel to layer surface. The central part of the picture was blocked by a beam stop to avoid an over-saturation of the CCD detector. More details can be found in the article by Jörg Grenzer et al. on page 478. [source]


Macromolecular crystallography at high pressure with pneumatic diamond anvil cells handled by a six-axis robotic arm

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2010
Eric Girard
A new pneumatic diamond anvil cell has been constructed, generating continuous pressure and temperature variations in the range 0,2.5,GPa and 293,393,K. The cell is designed mainly for high-pressure macromolecular crystallography and should facilitate pressure and temperature annealing of the sample. The analysis is reported of several diffraction data sets of tetragonal hen egg-white lysozyme crystals loaded either in the new cell or in a currently used membrane-based cell. These experiments were performed on beamline FIP-BM30A at the ESRF, Grenoble, a macromolecular crystallography beamline on a bending magnet. Cells were handled and automatically centred by a six-axis robotic arm that was used as a goniometer for data collection by the oscillation method. [source]


Online collection and analysis of X-ray fluorescence spectra on the macromolecular crystallography beamlines of the ESRF

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2009
Gordon A. Leonard
X-ray fluorescence (XRF) measurements on solutions or crystals of biological macromolecules provide additional information that can be used in structure determination and/or refinement protocols. Here details are presented of an experimental setup, employed on all the ESRF Macromolecular Crystallography Group beamlines, that allows the online collection and qualitative analysis of XRF spectra. This experimental setup uses a highly attenuated beam and short exposures, meaning it is minimally destructive but retains high sensitivity. [source]


In situ investigation of the non-linear optical crystal rubidium titanyl arsenate, RbTiOAsO4, under applied electric field using X-ray imaging

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3 2007
P. A. Thomas
Recent work on the non-linear optical single-crystal rubidium titanyl arsenate (RbTiOAsO4, RTA) has shown that it exhibits behaviour consistent with a ferroelectric semiconductor under large applied electric fields, with the development of a non-uniform field in the near-surface region. To confirm aspects of the proposed model, the behaviour of 001 slices of initially single-domain RTA, patterned with periodic Ag electrodes of spacing 38,µm, as for periodic poling in non-linear optics, were investigated using synchrotron X-ray section topography with the electric field applied in situ while under X-ray illumination at the ID19 topography beamline of the ESRF, Grenoble. The results of white-beam section topography as both a function of crystal to film distance, and under DC voltage are reported, confirming that there is a bending of the planes in the near-surface region. The strain in the near-surface region was examined directly using high-resolution monochromatic X-ray section topography. This revealed an extensive strain of 3,(±1) × 10,4 at 1,kV, indicating that the electrostrictive coefficient, ,3333, in RTA is positive in sign. [source]


Instrument line-profile synthesis in high-resolution synchrotron powder diffraction

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2003
O. Masson
An accurate method for synthesizing the instrumental line profile of high-resolution synchrotron powder diffraction instruments is presented. It is shown that the instrumental profile can be modelled by the convolution of four physical aberration functions: the equatorial intensity distribution, the monochromator and analyser transfer functions, and the axial divergence aberration function. Moreover, each equatorial aberration is related to an angle-independent function by a scale transform factor. The principles of the instrument line-profile calculation are general. They are applied in the case of the angle-dispersive powder X-ray diffraction beamline BM16 at the ESRF. The effects of each optical element on the overall instrument profile are discussed and the importance of the quality of the different optical elements of the instrument is emphasized. Finally, it is shown that the high resolution combined with the precise modelling of the instrument profile shape give access to a particle size as large as 3,µm. [source]


The SAXS/WAXS software system of the DUBBLE CRG beamline at the ESRF

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2001
E. Homan
The small/wide-angle X-ray scattering (SAXS/WAXS) system on the DUBBLE CRG beamline at the ESRF is used for both static and time-resolved measurements. The integrated system developed for control and data reduction deals effectively with the high rates of incoming data from the different detector systems, as well as the presentation of results for the user. To ensure that the data may be used directly by a wide range of packages, they may be recorded in a number of output formats, thus serving as a practical test bed where developing standards may be compared and contrasted. The software system implements proposals raised at the canSAS meetings to promote a limited set of standard data formats for small-angle scattering studies. The system presented can cope with a volume of results in excess of 10,Gbytes of data per experiment and shows the advantages achieved by minimizing the dependence on raw-data formats. [source]


Microarchitectural and Physical Changes During Fetal Growth in Human Vertebral Bone,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2003
S Nuzzo
Abstract The ossification process in human vertebra during the early stage of its formation was studied by X-ray diffraction (XRD) and X-ray microtomography (,CT) at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. Twenty-two samples taken from vertebral ossification centers of human fetal bone (gestational age ranging between 16 and 26 weeks) were investigated. The analysis of three-dimensional images at high spatial resolution (,10 and ,2 ,m) allows a detailed quantitative description of bone microarchitecture. A denser trabecular network was found in fetal bone compared with that of adult bone. The images evidenced a global isotropic structure clearly composed of two regions: a central region (trabecular bone) and a peripheral region (immature bone). XRD experiments evidenced hydroxyapatite-like crystalline structure in the mineral phase at any fetal age after 16 weeks. Interestingly, the analysis of XRD patterns highlighted the evolution of crystalline structure of mineralized bone as a function of age involving the growth of the hydroxyapatite crystallites. [source]


RESEARCH INTO PAIN PERCEPTION WITH ARTERIOVENOUS FISTULA (AVF) CANNULATION

JOURNAL OF RENAL CARE, Issue 4 2008
Ana E. Figueiredo RN
SUMMARY Patients with end-stage renal failure (ESRF) undergoing haemodialysis (HD) are repeatedly exposed to stress and pain from approximately 300 punctures per year to their arteriovenous fistula (AVF). Repeated AVF punctures lead to a considerable degree of pain, due to the calibre and length of the bevel of fistula needles. Pain is a sensitive, emotional and subjective experience. The objective of this study was to measure pain associated with AVF needling. The analogue visual scale (AVS) divided into 10 equal parts (0 indicating lack of pain, and 10 unbearable pain) was used. Patients7 perceptions were measured in three different HD sessions. Pain was considered mild during AVF needling. The buttonhole technique caused a mean degree of pain of 2.4 (±1.7), compared to 3.1 (±2.3) using the conventional ropeladder technique. Although without reaching a statistically significant difference, diminished pain was associated with the buttonhole technique. [source]


MxCuBE: a synchrotron beamline control environment customized for macromolecular crystallography experiments

JOURNAL OF SYNCHROTRON RADIATION, Issue 5 2010
José Gabadinho
The design and features of a beamline control software system for macromolecular crystallography (MX) experiments developed at the European Synchrotron Radiation Facility (ESRF) are described. This system, MxCuBE, allows users to easily and simply interact with beamline hardware components and provides automated routines for common tasks in the operation of a synchrotron beamline dedicated to experiments in MX. Additional functionality is provided through intuitive interfaces that enable the assessment of the diffraction characteristics of samples, experiment planning, automatic data collection and the on-line collection and analysis of X-ray emission spectra. The software can be run in a tandem client-server mode that allows for remote control and relevant experimental parameters and results are automatically logged in a relational database, ISPyB. MxCuBE is modular, flexible and extensible and is currently deployed on eight macromolecular crystallography beamlines at the ESRF. Additionally, the software is installed at MAX-lab beamline I911-3 and at BESSY beamline BL14.1. [source]


X-ray magnetic circular dichroism measurements using an X-ray phase retarder on the BM25 A-SpLine beamline at the ESRF

JOURNAL OF SYNCHROTRON RADIATION, Issue 3 2010
Roberto Boada
Circularly polarized X-rays produced by a diamond X-ray phase retarder of thickness 0.5,mm in the Laue transmission configuration have been used for recording X-ray magnetic circular dichroism (XMCD) on the bending-magnet beamline BM25A (SpLine) at the ESRF. Field reversal and helicity reversal techniques have been used to carry out the measurements. The performance of the experimental set-up has been demonstrated by recording XMCD in the energy range from 7 to 11,keV. [source]


Wavelength-dispersive spectrometer for X-ray microfluorescence analysis at the X-ray microscopy beamline ID21 (ESRF)

JOURNAL OF SYNCHROTRON RADIATION, Issue 3 2010
J. Szlachetko
The development of a wavelength-dispersive spectrometer for microfluorescence analysis at the X-ray Microscopy ID21 beamline of the European Synchrotron Radiation Facility (ESRF) is reported. The spectrometer is based on a polycapillary optic for X-ray fluorescence collection and is operated in a flat-crystal geometry. The design considerations as well as operation characteristics of the spectrometer are presented. The achieved performances, in particular the energy resolution, are compared with the results of Monte Carlo simulations. Further improvement in the energy resolution, down to ,eV range, by employing a double-crystal geometry is examined. Finally, examples of applications requiring both spatial and spectral resolutions are presented. [source]


The ID23-2 structural biology microfocus beamline at the ESRF

JOURNAL OF SYNCHROTRON RADIATION, Issue 1 2010
David Flot
The first phase of the ESRF beamline ID23 to be constructed was ID23-1, a tunable MAD-capable beamline which opened to users in early 2004. The second phase of the beamline to be constructed is ID23-2, a monochromatic microfocus beamline dedicated to macromolecular crystallography experiments. Beamline ID23-2 makes use of well characterized optical elements: a single-bounce silicon (111) monochromator and two mirrors in Kirkpatrick,Baez geometry to focus the X-ray beam. A major design goal of the ID23-2 beamline is to provide a reliable, easy-to-use and routine microfocus beam. ID23-2 started operation in November 2005, as the first beamline dedicated to microfocus macromolecular crystallography. The beamline has taken the standard automated ESRF macromolecular crystallography environment (both hardware and software), allowing users of ID23-2 to be rapidly familiar with the microfocus environment. This paper describes the beamline design, the special considerations taken into account given the microfocus beam, and summarizes the results of the first years of the beamline operation. [source]


Achievements in high-pressure science at the high-brilliance energy-dispersive X-ray absorption spectrometer of ESRF, ID24

JOURNAL OF SYNCHROTRON RADIATION, Issue 6 2009
Giuliana Aquilanti
Although the idea of an X-ray absorption spectrometer in dispersive geometry was initially conceived for the study of transient phenomena, the instrument at the European Synchrotron Radiation facility has been increasingly exploited for studies at extreme conditions of pressure using diamond anvil cells. The main results of investigations at high pressure obtained at beamline ID24 are reviewed. These concern not only fundamental topics, such as the local and the electronic structure as well as the magnetic properties of matter, but also geological relevant questions such as the behaviour of Fe in the main components of the Earth's interior. [source]


Phonon spectroscopy at high pressure by inelastic X-ray scattering

JOURNAL OF SYNCHROTRON RADIATION, Issue 6 2009
Valentina M. Giordano
The current status of phonon-dispersion studies at high pressure using very high energy resolution inelastic X-ray scattering is discussed. A brief description of the instrumental apparatus is given, together with an illustration of the high-pressure facilities available at the IXS beamlines ID16 and ID28 of the ESRF. Some selected examples of recent studies on crystalline and liquid samples in a diamond anvil cell are then presented. [source]


Upgrade of the CATS sample changer on FIP-BM30A at the ESRF: towards a commercialized standard

JOURNAL OF SYNCHROTRON RADIATION, Issue 1 2009
L. Jacquamet
An upgraded version of the sample changer `CATS' (Cryogenic Automated Transfer System) that was developed on the FIP-BM30A beamline at the ESRF is presented. At present, CATS is installed at SLS (three systems), BESSY (one system), DLS (two systems) and APS (four systems for the LSCAT beamline). It consists mainly of an automated Dewar with an assortment of specific grippers designed to obtain a fast and reliable mounting/dismounting rate without jeopardizing the flexibility of the system. The upgraded system has the ability to manage any sample standard stored in any kind of puck. [source]


XAS and XMCD under high magnetic field and low temperature on the energy-dispersive beamline of the ESRF

JOURNAL OF SYNCHROTRON RADIATION, Issue 5 2007
O. Mathon
The present paper demonstrates the feasibility of X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) under high magnetic fields up to 26,T and low temperatures down to 5,K on the ID24 energy-dispersive XAS beamline of the ESRF. The pulsed magnetic field set-up, entirely developed at the ESRF, is described as well as the beamline set-up, the synchronization and the measurement procedure. It allows field strengths up to 30,T. Finally, as an example, we report a recent XMCD study at the Re L2 and L3 absorption edges of the double perovskite Sr2CrReO6. [source]


Energy-dispersive absorption spectroscopy for hard-X-ray micro-XAS applications

JOURNAL OF SYNCHROTRON RADIATION, Issue 5 2006
S. Pascarelli
Originally developed for time-resolved X-ray absorption spectroscopy (XAS), energy-dispersive absorption spectroscopy offers new opportunities for applications such as fluorescence detection and microbeams for scanning probe spectroscopy, thanks to recent developments in both instrumentation and optics. In this context, this paper presents a first example of chemical mapping recorded at ID24, the energy-dispersive XAS beamline at the ESRF. Attributes of this geometry for microanalysis are addressed. Finally, present and future plans are discussed and developed in the light of the evolution of the focal spot on this instrument in the past ten years. [source]


The ID23-1 structural biology beamline at the ESRF

JOURNAL OF SYNCHROTRON RADIATION, Issue 3 2006
Didier Nurizzo
The demand for access to macromolecular crystallography synchrotron beam time continues to increase. To meet this demand the ESRF has constructed a dual station beamline using a canted undulator system as the X-ray source. The first phase of the beamline to be constructed is ID23-1, a tunable MAD-capable station with a mini-focus X-ray beam. The beamline makes use of well characterized optical elements: a channel-cut monochromator with a high-precision toroidal mirror to focus the X-ray beam. The beamline has been conceived with the aim of providing high levels of automation to create an industrial-like environment for protein crystallography. A new software suite has been developed to permit reliable easy operation for the beamline users and beamline staff. High levels of diagnostics are built in to allow rapid trouble-shooting. These developments are now being exported to the ESRF macromolecular crystallography beamline complex and have been made in a modular fashion to facilitate transportability to other synchrotrons. [source]


Too hot to handle?

JOURNAL OF SYNCHROTRON RADIATION, Issue 6 2002
Synchrotron X-ray damage of lipid membranes, mesophases
The call for brighter synchrotron X-radiation sources for use in structural biology research is barely audible as we enter the new millennium. Our brightest sources are already creating havoc when used at design specifications because of radiation damage. The time is long overdue to take stock of where we are and where we wish to go with regards to using existing sources and to designing new ones. The problem of radiation damage is particularly acute in studies involving kinetics and mechanisms where cryo-techniques are not always viable. Accordingly, we need to understand the very nature of radiation damage and to devise means of minimizing it. This is the thrust of the current report as applied to lipid membranes and mesophases. The experiments were performed at the most brilliant beamlines at CHESS, the APS and the ESRF. Two very different types of radiation damage are reported here. One involves a dramatic phase transformation and the other a disordering of lamellar stacking. How beam energy and dose rate affect damage is also discussed. The work highlights the free-radical-mediated nature of the damage process and the need for additional studies if the most efficient use is to be made of an important resource, synchrotron radiation. [source]


Present state and perspectives of synchrotron radiation diffraction imaging

JOURNAL OF SYNCHROTRON RADIATION, Issue 3 2002
J. Baruchel
The modern third-generation synchrotron radiation sources offer enhanced possibilities for all variants of imaging techniques. The quantitative and qualitative improvements with respect to previous synchrotron diffraction imaging work, which include the investigation in transmission of bulky samples, the use, as an additional parameter, of the sample-to-detector distance, and the use of the coherence of the beam, are illustrated by several examples. Emphasis is given to the possibilities associated with modern electronic detectors for this type of imaging. The new techniques implemented at the ESRF that take full advantage of new capabilities, and more particularly that of `topo-tomography', are presented. [source]


The XMaS beamline at ESRF: instrumental developments and high-resolution diffraction studies

JOURNAL OF SYNCHROTRON RADIATION, Issue 6 2001
S. D. Brown
The beamline, which is situated on a bending magnet at ESRF, comprises a unique combination of instrumentation for high-resolution and magnetic single-crystal diffraction. White-beam operation is possible, as well as focused and unfocused monochromatic modes. In addition to an eleven-axis Huber diffractometer, which facilitates simple operation in both vertical and horizontal scattering geometries, there is an in-vacuum polarization analyser and slit system, mirrors for harmonic rejection, sub 4.2,K and 1,Tesla magnetic field sample environment, plus a diamond phase plate for polarization conditioning. The instrumentation developed specifically for this beamline is described, and its use illustrated by recent scientific results. [source]


Phase imaging using highly coherent X-rays: radiography, tomography, diffraction topography

JOURNAL OF SYNCHROTRON RADIATION, Issue 3 2000
José Baruchel
Several hard X-rays imaging techniques greatly benefit from the coherence of the beams delivered by the modern synchrotron radiation sources. This is illustrated with examples recorded on the `long' (145,m) ID19 `imaging' beamline of the ESRF. Phase imaging is directly related to the small angular size of the source as seen from one point of the sample (`effective divergence' , microradians). When using the `propagation' technique, phase radiography and tomography are instrumentally very simple. They are often used in the `edge detection' regime, where the jumps of density are clearly observed. The in situ damage assessment of micro-heterogeneous materials is one example of the many applications. Recently a more quantitative approach has been developed, which provides a three-dimensional density mapping of the sample (`holotomography'). The combination of diffraction topography and phase-contrast imaging constitutes a powerful tool. The observation of holes of discrete sizes in quasicrystals, and the investigation of poled ferroelectric materials, result from this combination [source]


Primary hyperoxaluria: Simultaneous combined liver and kidney transplantation from a living related donor

LIVER TRANSPLANTATION, Issue 4 2003
Ibrahim Astarcioglu
Primary hyperoxaluria type 1 (PH1) is a rare inherited metabolic disorder in which deficiency of the liver enzyme AGT leads to renal failure and systemic oxalosis. Timely, combined cadaveric liver-kidney transplantation (LKT) is recommended for end-stage renal failure (ESRF) caused by PH1; however, the shortage of cadaveric organs has generated enthusiasm for living-related transplantation in years. Recently, successful sequential LKT from the same living donor has been reported in a child with PH1. We present a sister-to-brother simultaneous LKT in a pediatric patient who suffered from PH1 with ESRF. Twelve months after transplantation, his daily urine oxalate excretion was decreased from 160 mg to 19.5 mg with normal liver and renal allograft functions. In addition to the well-known advantages of living organ transplantation, simultaneous LKT may facilitate early postoperative hemodynamic stability and may induce immunotolerance and allow for low-dose immunosuppression. [source]


Polymorphism of renin-angiotensin system genes in IgA nephropathy

NEPHROLOGY, Issue 5 2004
KENG-THYE WOO
SUMMARY: Background and Aims: Individuals are prone to disease because of certain disease-susceptible genes. The angiotensin I-converting enzyme (ACE) gene insertion/deletion (I/D), the angiotensinogen (AGT) gene, M235T, and the angiotensin II type 1 receptor (ATR) gene, A1166C, polymorphisms have been associated with IgA nephropathy (IgAN) and its progression. Several studies on Caucasians and Japanese patients have reported contradictory results. We determined these polymorphisms in 118 Chinese patients with IgAN and 94 healthy Chinese subjects to assess their clinical impact. Methods: Genotyping was performed with DNA isolated from peripheral leucocytes, polymerase chain reaction amplification of the polymorphic sequence, restriction enzymes digestion, and separation and identification of DNA fragments. Clinical data at renal biopsy and final status on renal function were determined from patients' records. Results: Comparing all IgAN patients with controls, AGT and ATR genotype distributions were similar, whereas there was a significant increase in the ACE DD genotype (P < 0.05). When comparing patients with end-stage renal failure (IgAN-ESRF) and those without (IgAN-nonESRF), there was no difference among the three gene polymorphisms. In contrast, there were significant differences in higher male prevalence (P < 0.05), increased serum creatinine at presentation (P < 0.05), more sclerosis (P < 0.01) and higher tubulointerstitial lesion score (P < 0.001) in the IgAN-ESRF group. Conclusion: Among the ACE, AGT and ATR gene polymorphisms, only the DD genotype may predispose the individual to IgAN in the Chinese population. None are significant for prognosticating ESRF. [source]


First experiences of pediatric kidney transplantation in Sri Lanka

PEDIATRIC TRANSPLANTATION, Issue 4 2007
C. K. Abeysekera
Abstract:, KT is the most effective therapeutic option for ESRF. We present our first experiences in a developing country. All children who underwent kidney transplantation since the inception of this program in July 2004 until 30 September 2005 were studied. Their demographic data, operative and peri-operative details, graft and host survival, and drug compliance are described here. Data were collected from patient records and nursing observation records. Eleven children were transplanted during this period (median recipient age 10.75 yr, range: 8,16). The median age of the donors was 41 yr (range: 38,45) and was the mother in eight, father in two and uncle in one. The median (range) follow-up period following transplantation was 12.5 months (7,12). The vascular anastomotic site was aorta and inferior vena cava in nine patients and the cold ischemia time was mean (s.d.) 1.9 h (0.96). All patients received steroids, cyclosporine and MMF for immunosuppression. Hypotension, heart failure and septicemia were common medical complications. Four were treated for acute rejection. Vascular anastomotic leak, burst abdomen, intestinal obstruction, intra-abdominal leak of supra pubic catheter and vesico-ureteric junction obstruction were surgical complications. There were no graft losses or deaths. Despite limited resources good outcomes are possible following renal transplantation in children in developing countries. [source]


Pediatric renal transplantation in a South African teaching hospital: A 20-year perspective

PEDIATRIC TRANSPLANTATION, Issue 4 2006
G. J. Pitcher
Abstract:, Introduction:, Renal transplantation is established as the standard of care for end-stage renal failure (ESRF) in the developed world. In emerging nations, the appropriateness of such costly interventions has been questioned. We undertook an analysis of all renal transplants undertaken under the care of the pediatric nephrology service at the Johannesburg Hospital, South Africa, in order to establish the outcomes of a transplantation service in a resource-constrained environment in a developing country. Methods:, This was a retrospective review of renal transplantation undertaken at a single teaching hospital in Johannesburg, part of the University of the Witwatersrand. Two hundred and eighty-two transplants were performed between 1984 and 2003. Demographic characteristics of the transplanted population, diagnosis, morbidity, graft survival, and mortality were recorded. Results:, Overall 1-, 5-, and 10-yr graft survival was 82, 44, and 23%. Overall 1-, 5-, and 10-yr patient survival was 97, 84, and 68%. The median graft survival for all transplantation episodes was 4.38 yr; 70% of patients survive 10 yr and 54% survive 20 yr or more. Although early graft survival was good, there was a more rapid rate of graft loss than when compared to results from developed centers with much poorer results at 5 and 10 yr. Causes of ESRF show marked variation between the races, and black patients have significantly worse outcomes than others. Compared with white patients, black recipients received fewer living donor kidneys (26 vs. 10%, p = 0.0019), a greater proportion of totally mismatched organs (56 vs. 36%, p = 0.015), less pre-emptive transplantation (7 vs. 35%, p = 0.0001) and experienced a higher rate of primary non-function (13 vs. 3%, p = 0.004). Surgical complications of transplantation occurred in 9% of recipients, but rarely led to graft loss. Conclusion:, Pediatric renal transplantation in Johannesburg can be accomplished with low complication rates, but medium and long-term graft survival is poor when compared with contemporary results achieved in developed countries. The difficulties of undertaking such complex, multidisciplinary interventions in a developing nation are daunting, but we believe that renal transplantation should still be the treatment of choice for all children with ESRF. The poorer outcomes in black recipients can be addressed by increasing education in our communities and expanding the pool of appropriate donors. Better institutional support would allow for improved long-term patient care. [source]


New strepsirrhine primate from the late Eocene of Peninsular Thailand (Krabi Basin)

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2006
Laurent Marivaux
Abstract In this paper, we describe the newly discovered lower jaw of a primate from the late Eocene Krabi coal mine (Bang Mark pit) of Peninsular Thailand. We performed microtomographic examinations at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) to analyze different morphological aspects of the jaw and teeth. Although partially preserved, this fossil mandible reveals a set of distinctive dental traits (e.g., double-rooted P2 and molarized P4) that allow us to describe a new stepsirrhine adapiform: Muangthanhinius siami, new genus and species. This taxon is somewhat atypical among Paleogene adapiforms, and more specialized than the sivaladapid adapiforms (hoanghoniines) that existed in Asia in the same epoch. In fact, Muangthanhinius shows a degree of dental specialization approximating that of some modern strepsirrhine lemuriforms, although it lacks the highly specialized anterior dentition characterizing this living primate group (canine + incisors forming a very procumbent toothcomb). In contrast, Muangthanhinius exhibits a large canine deeply anchored within the dentary that probably protruded high above the toothrow. Finally, despite the development of a molarized P4 as in Miocene sivaladapid sivaladapines, Muangthanhinius differs in molar morphology from this group, and the position of this new taxon within the Adapiformes remains indeterminate. Clarification of its phylogenetic position will require more morphological evidence than is currently available. Am J Phys Anthropol, 2006. © 2006 Wiley-Liss, Inc. [source]


Successful Lung Transplantation in an HIV- and HBV-Positive Patient with Cystic Fibrosis

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2009
A. Bertani
Prior to the advent of highly active antiretroviral therapy (HAART), HIV-infected patients were usually not considered as transplant candidates because of the poor prognosis of their underlying disease and concerns regarding the potential detrimental effects of immunosuppression on viral load and immune status. However, with the significant HAART-associated improvements in morbidity and mortality, good short-term outcomes after liver and kidney transplantation for patients with HIV infection have been reported. Nevertheless, HIV infection is currently considered a contraindication to lung transplantation in most transplant centers worldwide. The results of a double lung transplant performed in an HIV and HBV co-infected patient with cystic fibrosis (CF) and end-stage respiratory failure (ESRF) are presented after a 2-year follow-up. Approval of and recommendations for the management of this patient were obtained from the Italian National Center for Transplantation as an extension of the ongoing Italian protocol for liver and kidney transplantation in HIV-infected individuals. The operation was successful and the patient recovered rapidly after surgery. A cautious infectious and immunosuppressive management allowed so far the avoidance of major infectious complications and rejection. To the best of our knowledge, this is the first report of lung transplantation in an HIV and HBV co-infected patient. [source]


The structure of Vibrio cholerae extracellular endonuclease I reveals the presence of a buried chloride ion

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2006
Bjørn Altermark
The crystal structure of a periplasmic/extracellular endonuclease from Vibrio cholerae has been solved at low and at neutral pH. Crystals grown at pH 4.6 and 6.9 diffracted to 1.6,Å (on BM01A at the ESRF) and 1.95,Å (on a rotating-anode generator), respectively. The structures of the endonuclease were compared with the structure of a homologous enzyme in V. vulnificus. The structures of the V. cholerae enzyme at different pH values are essentially identical to each other and to the V. vulnificus enzyme. However, interesting features were observed in the solvent structures. Both V. cholerae structures reveal the presence of a chloride ion completely buried within the core of the protein, with the nearest solvent molecule approximately 7,Å away. Magnesium, which is essential for catalysis, is present in the structure at neutral pH, but is absent at low pH, and may partly explain the inactivity of the enzyme at lower pH. [source]


Purification, crystallization, X-ray diffraction analysis and phasing of a Fab fragment of monoclonal neuroantibody ,D11 against nerve growth factor

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2004
Sonia Covaceuszach
The rat monoclonal neuroantibody ,D11 is a potent antagonist that prevents the binding of nerve growth factor (NGF) to its tyrosine kinase A receptor (TrkA) in a variety of systems, most notably in two in vivo systems linked to crucial pathological states, such as Alzheimer's disease and HIV infection. To provide further insights into the mechanism of action of this potentially therapeutic monoclonal antibody, structural studies of the antigen-binding fragment (Fab) of ,D11 were performed. ,D11 IgG2a immunoglobulin was obtained from hybridomas by in vitro tissue culture. The ,D11 Fab crystallizes in two crystal forms. Form I belongs to space group P1, with unit-cell parameters a = 42.7, b = 50.6, c = 102.7,Å, , = 82.0, , = 89.1, , = 86.0°. With two molecules in the asymmetric unit, VM is 2.3,Å3,Da,1 and the solvent content is 46%. A complete data set has been collected at 2.7,Å resolution on beamline XRD-1 (ELETTRA, Trieste, Italy). Form II belongs to space group C2, with unit-cell parameters a = 114.8, b = 69.4, c = 64.10,Å, , = 117.0°. With one molecule in the asymmetric unit, VM is 2.4,Å3,Da,1 and the solvent content is 48%. A complete data set has been collected at 1.7,Å resolution on beamline ID14-1 (ESRF, Grenoble, France). Phasing was successfully performed by Patterson search techniques and refinement of the structures is currently under way. Crystal forms I and II display a close-packing pattern. [source]