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Search Results: 1 - 10 of 19766 matches for " Alexander Lembcke "
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Comparison of free breathing versus breath-hold in perfusion imaging using dynamic volume CT
Sonja Kandel,Henning Meyer,Patrik Hein,Alexander Lembcke,Jens-C. Rueckert,Patrik Rogalla
Insights into Imaging , 2012, DOI: 10.1007/s13244-012-0169-9
Abstract: Image registration is crucial for CT perfusion imaging.
Reducing Radiation Dose in Emergency CT Scans While Maintaining Equal Image Quality: Just a Promise or Reality for Severely Injured Patients?
Ulrich Grupp,Max-Ludwig Sch?fer,Henning Meyer,Alexander Lembcke,Alexander P?llinger,Gero Wieners,Diane Renz,Philipp Schwabe,Florian Streitparth
Emergency Medicine International , 2013, DOI: 10.1155/2013/984645
Abstract: Objective. This study aims to assess the impact of adaptive statistical iterative reconstruction (ASIR) on CT imaging quality, diagnostic interpretability, and radiation dose reduction for a proven CT acquisition protocol for total body trauma. Methods. 18 patients with multiple trauma ( ) were examined either with a routine protocol ( ), 30% ( ), or 40% ( ) of iterative reconstruction (IR) modification in the raw data domain of the routine protocol (140?kV, collimation: 40, noise index: 15). Study groups were matched by scan range and maximal abdominal diameter. Image noise was quantitatively measured. Image contrast, image noise, and overall interpretability were evaluated by two experienced and blinded readers. The amount of radiation dose reductions was evaluated. Results. No statistically significant differences between routine and IR protocols regarding image noise, contrast, and interpretability were present. Mean effective dose for the routine protocol was ?mSv, ?mSv for the IR 30, and ?mSv for the IR 40 protocol, that is, 22.1% effective dose reduction for IR 30 ( ) and 30.8% effective dose reduction for IR 40 ( ). Conclusions. IR does not reduce study interpretability in total body trauma protocols while providing a significant reduction in effective radiation dose. 1. Introduction The use of computed tomography (CT) brought enormous benefits to modern medicine and diagnostic CT examinations are increasingly used in recent years because of their speed, availability, and diagnostical power. In particular, for patients with polytrauma during the early resuscitation phase, whole-body CT is recommended as the standard diagnostic modality [1]. However, the common utilization of CT is accompanied by a steady increase in the population’s cumulative exposure to ionizing radiation [2, 3]. As X-rays have been classified as “carcinogen,” new efforts to minimize radiation exposure were undertaken to meet rising concerns of possible long-term cancer, especially regarding pediatric and young patients as well as patients undergoing several follow-up CT examinations [4]. A plurality of approaches, from “AEC” (automated exposure control) to “X-ray beam collimation,” led to a significant reduction in radiation dose [5, 6]. With the fast advancement of computational power, the technique of iterative reconstruction (IR), well known from SPECT and PET imaging, became the center of attention for CT adaption in recent years [7–10]. The group of severely injured patients is of great concern for dose reduction as these patients may be of a young age and standard
Resentimiento en adolescentes escolares de condición socio-económica alta y baja
Ramón León,Roxana Gómez Sánchez Lembcke
Revista de Psicología , 1988,
Abstract: El resentimiento de adolescentes escolares, de ambos sexos, de nivel socioeconómico bajo y adolescentes mujeres de nivel alto fue explorado con la Escala de León el al. y la sub-escala de Buss-Dutkee. Con la primera, no se detectaron diferencias sexuales al interior del nivel bajo, pero si a nivel socioeconómico (mayor resentimiento en las adolescentes de nivel bajo), encontrándose también diferencias con ítem específicos. Con la sub-escala de Buss-Dutkee, los sexos diferían solamente en un ítem (7); pero a nivel socioeconómico se advirtieron diferencias en cuatro de los ocho ítem.
Portraying the Expression Landscapes of B-CellLymphoma-Intuitive Detection of Outlier Samples and of Molecular Subtypes
Lydia Hopp,Kathrin Lembcke,Hans Binder,Henry Wirth
Biology , 2013, DOI: 10.3390/biology2041411
Abstract: We present an analytic framework based on Self-Organizing Map (SOM) machine learning to study large scale patient data sets. The potency of the approach is demonstrated in a case study using gene expression data of more than 200 mature aggressive B-cell lymphoma patients. The method portrays each sample with individual resolution, characterizes the subtypes, disentangles the expression patterns into distinct modules, extracts their functional context using enrichment techniques and enables investigation of the similarity relations between the samples. The method also allows to detect and to correct outliers caused by contaminations. Based on our analysis, we propose a refined classification of B-cell Lymphoma into four molecular subtypes which are characterized by differential functional and clinical characteristics.
Anticuerpos IgA secretorios de la leche materna protectores contra la infección por Cryptosporidium parvum
CASTILLO,ROSA; GILMAN,ROBERT; MIRANDA,ELBA; ECHEVARRIA,MARIANO; LEMBCKE,JORGE; STERLING,CHARLES;
Parasitología al día , 2001, DOI: 10.4067/S0716-07202001000100001
Abstract: the protective effect of breast milk from 150 women on infection produced by protozoa cryptosporidium parvum of children under 2 years old living in a shantytown nearby lima, perú was studied. breast milk had specific secretory inmunoglobulin a (siga) antibodies to c. parvum antigen determined by inmunoelectrotransfer blot (eitb) assay. each mother secreted milk with different composition of specific secretory iga antibodies against 15 proteins of c. parvum antigen with molecular weight 15-158 k-da, remained constant during the 24 month lactation period. the risk of c. parvum infection was reduced in children breast milk with specific secretory iga against proteins of high molecular weight c. parvum antigen (158, 123 y 97 k-da), protecting the breast fed baby from infection
Impact of Fast-Track Concept Elements in the Classical Pancreatic Head Resection (Kausch-Whipple Procedure)
Ingo Gastinger, Frank Meyer, Thomas Lembcke, Uwe Schmidt, Henry Ptok, Hans Lippert
Polish Journal of Surgery , 2012, DOI: 10.2478/v10035-012-0066-4
Abstract: The aim of the study was to determine statistically significant factors with an impact on the early postoperative surgical outcome. Material and methods. The influence of applied fast-track components on surgical results and early postoperative outcome in 143 consecutive Kausch-Whipple procedure patients was evaluated in a single-center retrospective analysis of a prospective collection of patient-associated pre-, peri- and postoperative data from 1997-2006. Results. The in-hospital mortality rate was 2.8% (n=4). Fast-track measures were shown to have no effect on the morbidity rate in the multi-variate analysis. Over the study period, a decrease of intraoperative infusion volume from 14.2 mL/kg body weight/h in the first year to 10.7 mL/kg body weight/h in the last year was accompanied by an increase in patients requiring intraoperative catecholamines, up from 17% to 95%. The administration of ropivacain/sufentanil via thoracic peri-dural catheter injection initiated in 2000 and now considered the leading analgesic method, was used in 95% of the cases in 2006. Early extubation rate rose from 16.6% to 57.9%. Conclusions. Fast-track aspects in the perioperative management have become more important in several surgical procedure even in those with a greater invasiveness such as Kausch-Whipple. However, such techniques used in peri-operative management of Kausch-Whipple pancreatic-head resections had no impact on the morbidity rate. In addition, the low in-hospital mortality rate was particularly attributed to surgical competence.
Protection of Environment from Damaged Nuclear Station and Transparent Inflatable Blanket for Cities—Protection from Radioactive Dust and Chemical, Biological Weapons  [PDF]
Alexander Bolonkin
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.24037
Abstract: The author, in a series of previous articles, designed the “AB Dome” made of transparent thin film supported by a small additional air overpressure for the purpose of covering a city or other important large installations or sub-regions. In present article the author offers a variation in which a damaged nuclear station can be quickly covered by such a cheap inflatable dome. By containing the radioactive dust from the damaged nuclear station, the danger zone is reduced to about 2 km2 rather than large regions which requires the resettlement of huge masses of people and which stops indus-try in large areas. If there is a big city (as Tokyo) near the nuclear disaster or there is already a dangerous amount of radioactive dust near a city, the city may also be covered by a large inflatable transparent Dome. The building of a gi-gantic inflatable AB Dome over an empty flat surface is not difficult. The cover is spread on a flat surface and a venti-lator (fan system) pumps air under the film cover and lifts the new dome into place but inflation takes many hours. However, to cover a city, garden, forest or other obstacle course in contrast to an empty, mowed field, the thin film cannot be easily deployed over building or trees without risking damage to it by snagging and other complications. This article proposes a new method which solves this problem. The design is a double film blanket filled by light gas such as, methane, hydrogen, or helium - although of these, methane will be the most practical and least likely to leak. Sections of this AB Blanket are lighter than air and will rise in the atmosphere. They can be made on a flat area serving as an as-sembly area and delivered by dirigible or helicopter to station at altitude over the city. Here they connect to the already assembled AB Blanket subassemblies, cover the city in an AB Dome and protect it from bad weather, chemical, bio-logical and radioactive fallout or particulates. After assembly of the dome is completed, the light gas can be replaced by (heavier but cheaper) air. Two projects for Tokyo (Japan) and Moscow (Russia) are used in this paper for sample computation.
Filters and Ultrafilters as Approximate Solutions in the Attainability Problems with Constraints of Asymptotic Character  [PDF]
Alexander Chentsov
Intelligent Information Management (IIM) , 2010, DOI: 10.4236/iim.2010.29062
Abstract: Abstract problems about attainability in topological spaces are considered. Some nonsequential version of the Warga approximate solutions is investigated: we use filters and ultrafilters of measurable spaces. Attrac- tion sets are constructed. AMS (MOS) subject classification. 46A, 49 K 40.
Using of High Altitude Wind Energy  [PDF]
Alexander Bolonkin
Smart Grid and Renewable Energy (SGRE) , 2011, DOI: 10.4236/sgre.2011.22010
Abstract: Ground based, wind energy extraction systems have reached their maximum capability. The limitations of current de-signs are: wind instability, high cost of installations, and small power output of a single unit. The wind energy industry needs of revolutionary ideas to increase the capabilities of wind installations. This article suggests a revolutionary innovation which produces a dramatic increase in power per unit and is independent of prevailing weather and at a lower cost per unit of energy extracted. The main innovation consists of large free-flying air rotors positioned at high altitude for power and air stream stability, and an energy cable transmission system between the air rotor and a ground based electric generator. The air rotor system flies at high altitude up to 14 km. A stability and control is provided and systems enable the changing of altitude. This article includes six examples having a high unit power output (up to 100 MW). The proposed examples provide the following main advantages: 1) Large power production capacity per unit—up to 5,000 - 10,000 times more than conventional ground-based rotor designs; 2) The rotor operates at high altitude of 1 - 14 km, where the wind flow is strong and steady; 3) Installation cost per unit energy is low; 4) The installation is environmentally friendly (no propeller noise).
Production of Freshwater and Energy from Earth’s Atmosphere  [PDF]
Alexander Bolonkin
Smart Grid and Renewable Energy (SGRE) , 2011, DOI: 10.4236/sgre.2011.22011
Abstract: The author offers a new, cheap method for the extraction of freshwater from the Earth’s atmosphere. The suggested method is fundamentally dictinct from all existing methods that extract freshwater from air. All other industrial methods extract water from a saline water source (in most cases from seawater). This new method may be used at any point in the Earth except the Polar Zones. It does not require long-distance freshwater transportation. If seawater is not utilized for increasing its productivity, this inexpensive new method is very environmentally-friendly. The author’s method has two working versions: 1) In the first variant warm (or hot) atmospheric air is lifted by the inflatable tube in a high altitude and atmospheric water vapor is condensed into freshwater: 2) in the second version, the warm air is pumped 20-30 meters under the sea-surface. In the first version, wind and solar heating of air are used for causing air flow. In version 2) wind and fans are used for causing air movment. The first method does not need energy, the second needs a small amount. Moreover, in variant 1) the freshwater has a high pressure (> 30 or more atm) and can be used for production of energy such as electricity and in that way the freshwater cost is lower. For increasing the productivity the seawater is injected into air and a solar air heater may be used. The solar air heater produces a huge amount of electricity as a very powerful electrical generation plant. The offered electricity installation is 100 - 200 times cheaper than any common electric plant of equivalent output.
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