bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of stable xenon inhalation on intracranial pressure during measurement of cerebral blood flow in head injury
Authors: Plougmann Jan , Astrup Jens , Pedersen Jens , Gyldensted Carsten 
Published: May 2009

✓ Xenon-enhanced computerized tomography (CT) is well suited for measurements of cerebral blood flow (CBF) in head-injured patients. Previous studies indicated divergent results on whether inhalation of xenon may cause a clinically relevant increase in intracranial pressure (ICP). The authors employed Xe-enhanced CT/CBF measurements to study the effect of 20 minutes of inhalation of 33% xenon in oxygen on ICP, cerebral perfusion pressure (CPP), and arteriovenous oxygen difference (AVDO2) in 13 patients 3 days (mean 1 to 5 days) after severe head injury (Glasgow Coma Scale score ≤ 7). The patients were moderately hyperventilated (mean PaCO2 4.3 kPa or 32.3 mm Hg). Six patients were studied before and during additional hyperventilation. All 13 patients reacted with an increase in ICP and 11 with a decrease in CPP. The mean ICP increment was 6.9 ± 7.7 (range 2 to 17 mm Hg). The mean CPP decrement was −9.7 ± −14.6 (range 17 to 47 mm Hg). The time course of the ICP changes indicated that ICP increased rapidly during the first 5 to 6 minutes, then declined to a plateau (peak-plateau type in four of 13 patients), remained at a plateau (plateau type in six of 13), or continued to increase in three of 13, indicating individual variance in xenon reactivity. Additional hyperventilation had no effect on the xenon-induced increments in ICP but these occurred at lower ICP and higher CPP baseline levels. The AVDO2 values, an index of flow in relation to metabolism, indicated a complex effect of xenon on CBF as well as on metabolism.
This study indicates that xenon inhalation for Xe-CT CBF measurements in head-injured patients according to our protocol causes clinically significant increments in ICP and decrements in CPP. It is suggested that the effect of xenon is analogous to anesthesia induction. Individual variations were observed indicating possible individual tolerance, possible influence of type and extent of the cerebral injury, disturbances in cerebrovascular reactivity, and possible influence of medication. These effects of xenon suggest that hyperventilation should be ensured in patients with evidence of reduced compliance or high ICP. On the other hand, inhalation of stable xenon is not believed to pose a risk because no signs of cerebral oligemia or ischemia were indicated in the AVDO2 values.
Morbidity and mortality from elective surgery for asymptomatic, unruptured, intracranial aneurysms: a meta-analysis
Authors: King Joseph T. , Berlin Jesse A. , Flamm Eugene S. 
Published: May 2009

✓ A meta-analysis of the literature on morbidity and mortality from elective surgery for asymptomatic unruptured intracranial aneurysms was performed to obtain a more precise, accurate, and generalizable estimate of operative risk than is currently available. The authors used a MEDLINE search from 1966 to 1992, supplemented with manual searches, to locate studies containing four or more patients who had undergone elective surgery for these aneurysms. Only patients with asymptomatic, unruptured aneurysms were eligible for inclusion. Demographic and clinical data were collected from each series; aneurysms were categorized as incidental, multiple, or unclassifiable. Data were analyzed using Fisher's exact test and logistical regression.
There were twenty-eight articles containing data on 733 patients who met eligibility criteria. The mean patient age was 48.6 ± 5.5 years, and 55% ± 17% of the patients were women. There was a total of 30 deficits for a morbidity rate of 4.1% (95% confidence interval 2.8, 5.8%) and a total of seven deaths for a mortality rate of 1.0% (95% confidence interval 0.4, 2.0%). There was insufficient statistical power to detect a difference in morbidity or mortality rates related to study size, year of publication, or potential risk factors such as patient sex or age, or aneurysm size, location, or category (incidental, multiple, or unclassifiable) (for all analyses, p ≥ 0.16).
Elective surgery for asymptomatic unruptured intracranial aneurysms, as reported in the literature, has low rates of morbidity (4.1%) and mortality (1.0%). At present there is insufficient detail in the literature to understand the impact of patient and aneurysm characteristics on elective surgical outcomes.
Surgical excision of meningiomas involving the clivus: preoperative and intraoperative features as predictors of postoperative functional deterioration
Authors: Sekhar Laligam N. , Swamy Narayana K. S. , Jaiswal Viswadarshi , Rubinstein Elaine , Hirsch William E. , Wright Donald C. 
Published: May 2009

✓ Neurological deterioration is commonly seen after surgical excision of clival meningiomas; however, an understanding of the risk factors associated with postoperative deterioration can lead to improvements in outcome.
In 75 patients with clival meningiomas operated on over a 7-year period, the following data were studied: preoperative variables such as presenting Karnofsky scale score, age, sex, and prior operations or radiation therapy. Radiological findings on magnetic resonance imaging or arteriography, such as the development of the arachnoidal cleavage plane between tumor and the brain stem, brainstem edema, tumor size, extent of compression on the brain stem, vascular encasement, and blood supply from the basilar artery were among other data studied. In addition, intraoperative findings such as development of the arachnoid plane, vascular encasement, and the difficulty of dissection were noted. Finally, each patient's neurological and functional statuses were recorded at 1 week postoperatively and at follow-up examinations.
Early postoperative functional deterioration occurred in 45 patients (60%) and ranged from mild (30 patients) to severe (three patients). Significant improvement had occurred by the time of follow-up examination in all but four patients; however, permanent postoperative dysfunction was present in 12 patients. Statistical analysis revealed significant correlations between early functional deterioration and preoperative Karnofsky scale scores, male gender, radiological findings of the absence of an arachnoid plane, edema of the brain stem, and arteriographic supply from the basilar artery. Operative features included difficulty with dissection, an absent arachnoidal cleavage plane, and incomplete tumor resection. Permanent functional deterioration was statistically associated with the following: blood supply from the basilar artery, difficulty of dissection, incomplete tumor resection, and early postoperative dysfunction. Logistical regression analysis revealed that the most important risk factor for early postoperative deterioration was tumor size. Patients with large or giant tumors had a 6.7 to 13 times greater risk of functional deterioration, respectively, than patients with small- or medium-sized tumors. Excluding tumor size, the most important factor for permanent deterioration was blood supply from the basilar artery. Patients in this category had a 4.4 times greater risk of permanent functional deterioration.
Three stages of tumor relationship to the brainstem arachnoid and pial membranes are proposed. Based on the results of this clinical study of clival meningiomas, suggestions are made for changes in the management strategy of these difficult lesions.
The “filum intermedium” sign: focal in utero spinal cord infarct and extraspinal thecal sac
Authors: Mamelak Adam N. , Cogen Philip H. , Barkovich A. James 
Published: May 2009

✓ This report describes the unique case of a child born with paraplegia and a neurogenic bladder who was found to have a dysplastic, nonossified T-12 vertebral body, midline fusion of the T-12 neural arches, obliteration of the spinal canal at T-12, and an extraspinal thecal sac in the T11—L1 region. Neural tissue was focally absent from T9–12, but neural structures above and below were preserved. Narrowing of the thecal sac on myelograms and sagittal magnetic resonance images signifies in utero focal infarction of the spinal cord after neurulation but before formation of the posterior half of the spinal canal. The infarction resulted in severe focal narrowing of the thecal sac from T10—L1, resembling a premature and duplicated filum terminale; to denote the radiographic appearance of these anomalies, the authors have coined the term “filum intermedium” sign.
The extremely unusual radiographic findings in this child illustrate the important interactions between neural tube, neural crest, and somite in the development of the spinal cord and spinal column. Correlation of the radiographic findings with the embryological differentiation and migration of these structures suggests that the spinal anomalies were caused by a focal insult, probably vascular in origin, occurring between the sixth and eighth weeks of gestation. The identification of a focally narrowed thecal sac and spinal cord (the “filum intermedium” sign) localizes the time of the insult to between the first and third month of gestation, and therefore is a useful marker in understanding developmental malformation of the spinal cord.
Les déterminants de l'épidémie du VIH/SIDA en Afrique subsaharienne
Authors: Tsafack Temah Chrystelle 
Published: May 2009

Résumé	Cet article décompose l’impact des déterminants de l’évolution de l’épidémie du VIH/SIDA pendant la période 1997-2005. Après avoir classé ces déterminants en socio-économiques, socioculturels et épidémiologiques, nous essayons de déterminer l’impact de chaque groupe de déterminants sur le cours de l’épidémie en Afrique subsaharienne. A l’aide d’un modèle de panel utilisant les données de 42 pays africains, nous examinons le lien entre les trois catégories de déterminants et l’évolution de l’épidémie. Après avoir effectué une transformation logistique du taux de prévalence du VIH/SIDA, nous estimons notre modèle par les effets aléatoires et nous incluons une variable muette régionale parmi les déterminants pour capter les différences sous-régionales dans la diffusion de l’épidémie. La même équation est ensuite estimée en utilisant le taux d’incidence du VIH/SIDA. Enfin, nous estimons notre modèle par la méthode des moments généralisés (GMM) pour tenir compte des effets dynamiques dans l’évolution de l’épidémie. Nos résultats sont robustes et montrent que ce sont les variables épidémiologiques et socioculturelles qui ont un impact plus important sur l’évolution de l’épidémie. De plus, les variables socio-économiques les plus déterminantes pour l’épidémie sont les inégalités de revenu et les inégalités de genre.	Classification JEL : I10, I12, I19, 015
Effets économiques du paludisme sur les cultures de rente : l'exemple du café et du cacao en Côte d'Ivoire
Authors: Audibert Martine , Brun Jean-François , Mathonnat Jacky , Henry Marie-Claire 
Published: May 2009

Résumé Les secteurs du café et du cacao représentaient avant la crise politique en Côte d’Ivoire, approximativement 15 % du PNB et 40 % des exportations. La zone de production de ces deux cultures est la forêt, également zone d’endémie palustre. Leur exploitation est moins contraignante que celle des cultures vivrières comme le riz et l’igname qui, elles, demandent à être repiquées chaque année. Par contre, l’entretien du sol et le traitement des caféiers et des cacaoyers sont des tâches importantes car elles contribuent à l’amélioration des rendements et donc aux revenus monétaires des planteurs. Mais elles exposent les planteurs, par une présence accrue dans les champs, aux piqûres des anophèles et donc au risque de paludisme. Les agriculteurs de cette zone cultivent également du riz, en mode pluvial, mais aussi pour certains, en mode irrigué (culture de bas-fonds). L’objectif de cet article est double. Il est d’estimer d’une part l’effet du paludisme sur la production de café et de cacao et d’autre part l’effet du mode de production rizicole sur la transmission du paludisme. Trois équations, production de café, production de cacao et production de santé, sont estimées. Les données sont issues d’une étude menée en 1999 sur un échantillon de 750 ménages, répartis en 21 villages, en zone forestière. Les principaux résultats soulignent l’absence d’effet du paludisme sur la production de café et de cacao et concluent que la riziculture de bas-fonds n’est pas un facteur de risque pour la transmission du paludisme. Classification JEL : I12, O13
L'impact du paludisme sur l'éducation primaire : une analyse en coupe transversale des taux de redoublement et d'achèvement
Authors: Thuilliez Josselin 
Published: May 2009

Résumé Ce travail explore la relation entre le paludisme à P.falciparum – le seul mortel et le plus répandu – et l’éducation primaire en termes de résultats scolaires au niveau macroéconomique. L’analyse en coupe transversale réalisée montre que le lien entre les performances des enfants dans le primaire (mesurées par les taux de redoublement et d’achèvement dans le primaire) et l’indice de paludisme à P.falciparum utilisé est fort. Ces résultats laissent penser que l’accomplissement de l’objectif d’éducation universelle nécessite une approche plus large et non uniquement focalisée sur les dépenses d’éducation (publiques ou privées) mais aussi sur des dépenses de santé spécifiques. Pour améliorer la qualité de l’éducation, il faut également prendre en compte l’état de santé des enfants et les maladies affectant particulièrement leurs capacités cognitives dont le paludisme. Les dépenses spécifiques d’éducation et de santé pour faire face au fléau du paludisme devraient faire l’objet de recherches plus approfondies. Classification JEL : O15, I10, I20
Facteurs associés à l'abandon du traitement anti-tuberculeux dans la ville d'Antananarivo, Madagascar
Authors: Rakotonirina El-C. Julio , Ravaoarisoa Lantonirina , Randriatsarafara Fidiniaina Mamy , de Dieu Marie Rakotomanga Jean , Robert Annie 
Published: May 2009

Résumé Une étude épidémiologique analytique, basée sur un recueil rétrospectif de données, ayant inclus 442 patients, a été effectuée dans un des centres de traitement de la tuberculose de la ville d’Antananarivo, pour identifier les facteurs liés à l’abandon du traitement. Les résultats montrent que les hommes abandonnent plus le traitement que les femmes (OR = 1,81 [1,13 ; 3,03]). Parmi ceux qui habitent loin du centre, les malades de moins de 30 ans ont tendance à être plus irréguliers dans le suivi du traitement (OR = 3,43 [1,16 ; 10,15]). Il n’existe pas de relation statistiquement significative entre l’abandon au traitement et l’âge, la forme clinique, le régime thérapeutique et la résidence. Les responsables de chaque centre de traitement devraient être plus vigilants vis-à-vis des tuberculeux de sexe masculin et des jeunes patients. Ils devraient adapter les modalités de suivi selon ces facteurs de risque à l’abandon.
The Effect of International Courses on Nursing Practice at Jordanian Hospitals
Authors: Shudifat Raed , Hayajneh Ferial , Mahadeen Alia I. 
Published: May 2009

Background:
Recently, nursing education in Jordan has been radically reformed to fit social and organizational processes of globalization. Jordanian nurses are attending international courses to improve their nursing practice.

Methods:
This descriptive, qualitative study was aimed at identifying the impact of Jordanian nurses' participation in international courses on nursing practice in Jordan. Purposive sampling techniques were used. Two focus groups of Jordanian nurses who participated in international courses provided rich data.

Results:
Findings from the focus groups suggested that participation in international courses makes a significant contribution to nurses' professional and personal development.

Conclusion:
Jordanian nurses are challenged to find ways to actually apply the new skills and knowledge gained from these courses in their work.

J Contin Educ Nurs
2009;40(4):187–192.
Macroscopic Third-body Wear Caused by Porous Metal Surface Fragments in Total Hip Arthroplasty
Authors: Kleinhans Jennifer A. , Jakubowitz Eike , Seeger Joern B. , Heisel Christian , Kretzer J. Philippe 
Published: May 2009

Implants with surfaces of various porosities and pore sizes are in clinical use. This article demonstrates how macroscopic porous metal fragments can detach from the implant surface in total hip arthroplasty (THA) and cause significant third-body damage such as deep scratches and indentations in implants' bearing surfaces. Radiographs prior to revision surgery due to aseptic loosening of the acetabular component revealed the presence of numerous small metal fragments approximately 1 to 2 mm in size in the periarticular area. The size, shape, and material of the metal fragments (cobalt–chromium–molybdenum [CoCrMo]) indicated that they originated from the porous metal surface.
In this case, the acetabular liner composite material consisted of two-thirds polyurethane and one-third aluminium oxide ceramic. The femoral head was made of aluminium oxide ceramic. The aluminium oxide femoral head, which had been in situ for 21 years, showed no signs of macroscopic indentations or scratches, suggesting that an aluminium oxide bearing surface, which is significantly harder than the CoCrMo debris, is not significantly affected by metal debris embedment in the counterface material. The polyurethane–aluminium oxide composite material used for the acetabular liner is not comparable to a traditional ceramic bearing surface material. Debris damaged the surface of and became embedded in the liner, causing accelerated wear of the femoral head.
In porous metal surface THA, ceramic-on-ceramic bearing couples should, due to their superior hardness, be considered to prevent excessive wear, including debris embedment and scratching of the bearing surfaces, especially in revision cases.
Total Hip Arthroplasty in Patients With Underlying Fibrous Dysplasia
Authors: Sierra Rafael J. , Cabanela Miguel E. 
Published: May 2009

Fibrous dysplasia is a developmental anomaly of bone formation that accounts for approximately 7% of benign bone tumors. It exists in a monostotic or polyostotic form, commonly occurs in the proximal femur, and may require total hip arthroplasty (THA) for its management in a select group of patients. The results of THA in patients with this disorder is not known.
Of the 27,543 primary THAs performed at our institution between 1969 and 2001, 10 were in patients with fibrous dysplasia (prevalence of 0.04%). Two other patients (2 hips) with the same diagnoses were referred after a failed primary THA. The study group comprised 7 men and 4 women (1 bilateral) with an average age at primary THA of 44 years (range, 23–66 years). Four patients had the monostotic form and 7 patients had the polyostotic form. A cemented stem was used in 7 hips and cementless stem in the rest (N=12). Average follow-up was 15.7 years (range, 2–30 years). Seven hips in 6 patients were revised for loosening of components at an average of 12.5 years, and 2 of these were re-revised for the same reason. Loosening of a cementless femoral component led to early revision in 3 hips. The surgical outcomes for patients with monostotic was better than those with polyostotic disease.
Long-term fixation of the femoral component is of concern in patients with fibrous dysplasia. Total hip arthroplasty provided these patients with long-lasting pain relief and function despite the higher rate of complications at the time of surgery.
Transmission Electron Microscopy and UV–vis–IR Spectroscopy Analysis of the Diameter Sorting of Carbon Nanotubes by Gradient Density Ultracentrifugation
Authors: Fleurier Romain , Lauret Jean‐Sébastien , Lopez Ugo , Loiseau Annick 
Published: May 2009

AbstractDiameter separation of single‐walled carbon nanotubes is achieved via the density gradient ultracentrifugation process. Statistical analysis of the separated samples is performed using high‐resolution transmission electron microscopy (HRTEM). The evolution of the diameter distribution with respect to the gradient density is extracted by analyzing hundreds of HRTEM images, and the results are found to be consistent with those estimated by UV–vis–IR spectroscopy. The efficiency of the separation process can be quantitatively characterized by the standard deviation of the diameter distribution, which is determined from the TEM analyses. This particular study indicated that for electric arc nanotubes dispersed in sodium cholate, diameter sorting is more efficient in the upper part of the gradient.
PY181 Pigment Microspheres of Nanoplates Synthesized via Polymer‐Induced Liquid Precursors
Authors: Ma Yurong , Mehltretter Gerald , Plüg Carsten , Rademacher Nadine , Schmidt Martin U. , Cölfen Helmut 
Published: May 2009

AbstractOrganic pigments are important crystalline substances, and their properties and applications rely on size and shape control. Pigment Yellow 181 (PY181) is an industrial azo pigment that is light and weatherfast and suitable for high temperature processing. One disadvantage is its needle‐like shape in the default β‐phase, which makes the pigment difficult to process in industry, e.g., in polymer melts, where a spherical structure would be ideal. Here, we show for the first time, that polymer‐induced liquid precursor structures can be formed even in association to a chemical reaction. Furthermore, it is demonstrated that biomineralization principles can be exploited for the generation of advanced functional materials, such as pigments with novel complex morphology and different properties. Stable PY181 microspheres of nanoplates in the β‐phase were obtained in mixed solvents of water and isopropanol by direct azo coupling under the directing influence of a designed copolymer additive aminobenzoylaminobenzamide‐acetoacetyl‐poly(ethylene imine)‐block‐poly(ethylene glycol) (ABABA‐acetoacetyl‐PEI‐b‐PEG).
Artificial Stem Cell Niches
Authors: Lutolf Matthias P. , Blau Helen M. 
Published: May 2009

AbstractStem cells are characterized by their dual ability to reproduce themselves (self‐renew) and specialize (differentiate), yielding a plethora of daughter cells that maintain and regenerate tissues. In contrast to their embryonic counterparts, adult stem cells retain their unique functions only if they are in intimate contact with an instructive microenvironment, termed stem cell niche. In these niches, stem cells integrate a complex array of molecular signals that, in concert with induced cell‐intrinsic regulatory networks, control their function and balance their numbers in response to physiologic demands. This progress report provides a perspective on how advanced materials technologies could be used (i) to engineer and systematically analyze specific aspects of functional stem cells niches in a controlled fashion in vitro and (ii) to target stem cell niches in vivo. Such “artificial niches” constitute potent tools for elucidating stem cell regulatory mechanisms with the capacity to directly impact the development of novel therapeutic strategies for tissue regeneration.
Anionic Bridged Bis(amidinate) Lithium Lanthanide Complexes: Efficient Bimetallic Catalysts for Mild Amidation of Aldehydes with Amines
Authors: Wang Junfeng , Li Junmei , Xu Fan , Shen Qi 
Published: May 2009

Abstractmagnified imageAnionic bridged bis(amidinate) lithium lanthanide complexes have been found to be efficient catalysts for the amidation of aldehydes with amines under mild conditions. The activity follows the order: yttrium<neodymium<europium≈ ytterbium. The catalysts are available for the formation of benzamides derived from pyrrolidine, piperidine, and morpholine with good to excellent yields. In comparison with the corresponding neutral complexes, the anionic complexes show higher activity and a wider range of scope for the amines. A cooperation of the lanthanide and lithium metals in this process is proposed to contribute to the high activity of the present catalyst.