X-ray emission spectroscopic study of chloride solid compounds using synchrotron radiation

An x-ray emission spectrometer, developed at beamline 9.3.1 of the Advance Light Source (ALS), Lawrence Berkeley National Laboratory (LBNL), will allow performing measurements of x-ray emission from molecules and materials in gas, liquid and solid phases with energy, angle and polarization dependence. A two-dimensional position-sensitive detector system with data acquisition software is developed for the spectrometer that allows collecting a complete x-ray emission spectrum simultaneously. Mechanical supports for detector mounting and a holder for solid samples are designed and manufactured. Energy calibration, resolution, and performance of the detector system and the spectrometer are tested by studying a solid potassium chloride (KCl) sample with photon energies in the vicinity of Cl K edge. A detectable energy range of 55--60 eV with a resolution of 0.2 eV are obtained and reported. The detector system and data acquisition software are suitable for x-ray emission measurements

Prognostic Tools for Early Mortality in Hemorrhagic Stroke: Systematic Review and Meta-Analysis

Background and Purpose: Several risk scores have been developed to predict mortality in intracerebral hemorrhage (ICH). We aimed to systematically determine the performance of published prognostic tools. Methods: We searched MEDLINE and EMBASE for prognostic models (published between 2004 and April 2014) used in predicting early mortality (<6 months) after ICH. We evaluated the discrimination performance of the tools through a random-effects meta-analysis of the area under the receiver operating characteristic curve (AUC) or c-statistic. We evaluated the following components of the study validity: study design, collection of prognostic variables, treatment pathways, and missing data. Results: We identified 11 articles (involving 41,555 patients) reporting on the accuracy of 12 different tools for predicting mortality in ICH. Most studies were either retrospective or post-hoc analyses of prospectively collected data; all but one produced validation data. The Hemphill-ICH score had the largest number of validation cohorts (9 studies involving 3,819 patients) within our systematic review and showed good performance in 4 countries, with a pooled AUC of 0.80 [95% confidence interval (CI)=0.77-0.85]. We identified several modified versions of the Hemphill-ICH score, with the ICH-Grading Scale (GS) score appearing to be the most promising variant, with a pooled AUC across four studies of 0.87 (95% CI=0.84-0.90). Subgroup testing found statistically significant differences between the AUCs obtained in studies involving Hemphill-ICH and ICH-GS scores (p=0.01). Conclusions: Our meta-analysis evaluated the performance of 12 ICH prognostic tools and found greater supporting evidence for 2 models (Hemphill-ICH and ICH-GS), with generally good performance overall

Microscopic and spectroscopic studies of metal deposition on carbon-based materials

This dissertation is focused on studying the atomic and electronic structure of carbon-based materials, namely highly-ordered pyrolytic graphite (HOPG), single-walled carbon nanotubes (SWNT), and C60 fullerenes, with and without metal (Ti and Li) deposition. The work is motivated by ongoing efforts to understand and improve the hydrogen storage capability of carbon-based nanomaterials as well as their potential applications for developing novel electronic devices; Ti and Li deposition on the surface of SWNT, C60, and HOPG samples have been performed in ultra-high vacuum. The morphology and local geometric and electronic structure of the samples was investigated by scanning tunneling microscopy and spectroscopy (STM and STS). The chemical and electronic structure of the samples was studied by X-ray and UV photoelectron spectroscopy (PES). Changes in the carbon core- and valence-electronic levels upon metal deposition were observed and correlated with detailed morphological and electronic characteristics. The results give detailed information about the interaction between metal adatoms and carbon-based materials. In addition, several important aspects related to the deposited metals, such as the formation of oxides, were studied. The results provide fundamental insight into metal-carbon interactions and help to develop approaches to improve the performance of carbon-based materials for hydrogen storage and novel electronic devices

Intravenous tPA therapy does not worsen acute intracerebral hemorrhage in mice

Tissue plasminogen activator (tPA) is the only FDA-approved treatment for reperfusing ischemic strokes. But widespread use of tPA is still limited by fears of inadvertently administering tPA in patients with intracerebral hemorrhage (ICH). Surprisingly, however, the assumption that tPA will worsen ICH has never been biologically tested. Here, we assessed the effects of tPA in two models of ICH. In a mouse model of collagenase-induced ICH, hemorrhage volumes and neurological deficits after 24 hrs were similar in saline controls and tPA-treated mice, whereas heparin-treated mice had 3-fold larger hematomas. In a model of laser-induced vessel rupture, tPA also did not worsen hemorrhage volumes, while heparin did. tPA is known to worsen neurovascular injury by amplifying matrix metalloproteinases during cerebral ischemia. In contrast, tPA did not upregulate matrix metalloproteinases in our mouse ICH models. In summary, our experimental data do not support the assumption that intravenous tPA has a deleterious effect in acute ICH. However, due to potential species differences and the inability of models to fully capture the dynamics of human ICH, caution is warranted when considering the implications of these findings for human therapy

A participatory approach for digital documentation of Egyptian Bedouins intangible cultural heritage

The Bedouins of Egypt hold a unique intangible cultural heritage (ICH), with distinct cultural values and social practices that are rapidly changing as a consequence of having settled after having been nomadic for centuries. We present our attempt to develop a bottom-up approach to document Bedouin ICH. Grounded in participatory design practices, the project purpose was two-fold: engaging Egyptian Engineering undergraduates with culturally-distant technology users and introducing digital self-documentation of ICH to the Bedouin community. We report the design of a didactic model that deployed the students as research partners to co-design four prototypes of ICH documentation mobile applications with the community. The prototypes reflected an advanced understanding for the values to the Bedouins brought by digital documentation practices. Drawing from our experience, three recommendations were elicited for similar ICH projects. Namely, focusing on the community benefits; promoting motivation ownership, and authenticity; and pursuing a shared identity between designers and community members. These guidelines hold a strong value as they have been tested against local challenges that could have been detrimental to the project

Iodinated contrast media and cerebral hemorrhage after intravenous thrombolysis

&lt;p&gt;Background and Purpose: Iodinated contrast is increasingly used in CT perfusion or angiographic examinations in acute stroke. Increased risk of intracranial hemorrhage (ICH) complicating microcatheter contrast injections has recently been reported in the second Interventional Management of Stroke (IMS 2) trial with contrast toxicity potentially contributory.&lt;/p&gt; &lt;p&gt;Methods: We reviewed clinical and radiological data on all patients treated with intravenous alteplase at a single center between May 2003 and November 2008.&lt;/p&gt; &lt;p&gt;Results: Of 312 patients treated with intravenous alteplase, 69 (22.1%) received intravenous iodinated contrast in volumes between 50 and 150 mL. Incidence of symptomatic ICH defined as per European Cooperative Acute Stroke Study 2 was 16 of 312 (5.1%; 95% CI, 2.7% to 7.6%); among patients not given contrast, it was 12 of 243 (4.9%; 2.2% to 7.7%) compared with 4 of 69 (5.8%; 0.3% to 11.3%) in those given contrast. Incidence of symptomatic ICH defined as per Safe Implementation of Thrombolysis in Stroke-MOnitoring Study (SITS-MOST) criteria was 12 of 312 (3.9%; 1.7% to 6%), 9 of 243 (3.7%; 1.3% to 6%) among those not given contrast, and 3 of 69 (4.4%; 95% CI, -0.5% to 9.2%) among those given contrast. Patients with symptomatic ICH were older, had higher pretreatment National Institutes of Health Stroke Scale, and blood glucose than those without symptomatic ICH. In logistic regression analysis, pretreatment blood glucose was the only significant predictor of symptomatic ICH by either definition (OR, 1.23; 95% CI, 1.03 to 1.48 per mmol/L increment; P=0.024). Contrast administration or dose was not associated with symptomatic ICH.&lt;/p&gt; &lt;p&gt;Conclusions: Intravenous iodinated contrast in doses typically required for CT angiography and perfusion imaging was not associated with symptomatic intracranial hemorrhage in patients treated with alteplase.&lt;/p&gt

Secondary Hematoma Expansion and Perihemorrhagic Edema after Intracerebral Hemorrhage: From Bench Work to Practical Aspects.

Intracerebral hemorrhages (ICH) represent about 10-15% of all strokes per year in the United States alone. Key variables influencing the long-term outcome after ICH are hematoma size and growth. Although death may occur at the time of the hemorrhage, delayed neurologic deterioration frequently occurs with hematoma growth and neuronal injury of the surrounding tissue. Perihematoma edema has also been implicated as a contributing factor for delayed neurologic deterioration after ICH. Cerebral edema results from both blood-brain barrier disruption and local generation of osmotically active substances. Inflammatory cellular mediators, activation of the complement, by-products of coagulation and hemolysis such as thrombin and fibrin, and hemoglobin enter the brain and induce a local and systemic inflammatory reaction. These complex cascades lead to apoptosis or neuronal injury. By identifying the major modulators of cerebral edema after ICH, a therapeutic target to counter degenerative events may be forthcoming