Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 328
Filter
1.
Nanoscale ; 13(47): 20028-20033, 2021 Dec 13.
Article in English | MEDLINE | ID: mdl-34842882

ABSTRACT

We investigate the behavior of both pure spin and spin-polarized currents measured with four-probe non-local and two probe local configurations up to room temperature and under an external gate voltage in a lateral graphene transistor, produced using a standard large-scale microfabrication process. The high spin diffusion length of pristine graphene in the channel, measured both directly and by the Hanle effect, and the tuning of the relationship between the electrode resistance areas present in the device architecture allowed us to observe local tunnel magnetoresistance at room temperature, a new finding for this type of device. The results also indicate that while pure spin currents are less sensitive to temperature variations, spin-polarized current switching by an external voltage is more efficient, due to a combination of the Rashba effect and a change in carrier mobility by a Fermi level shift.

2.
Appl Microbiol Biotechnol ; 105(14-15): 5795-5807, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34268581

ABSTRACT

Pectin-rich residues are considered as promising feedstocks for sustainable production of platform chemicals. Enzymatic hydrolysis of extracted sugar beet press pulp (SBPP) releases the main constituent of pectin, D-galacturonic acid (D-GalA). Using engineered Saccharomyces cerevisiae, D-GalA is then reduced to L-galactonate (L-GalOA) with sorbitol as co-substrate. The current work addresses the combination of enzymatic hydrolysis of pectin in SBPP with a consecutive optimized biotransformation of the released D-GalA to L-GalOA in simple batch processes in stirred-tank bioreactors. Process conditions were first identified with synthetic media, where a product concentration of 9.9 g L-1 L-GalOA was obtained with a product selectivity of 99% (L-GalOA D-GalA-1) at pH 5 with 4% (w/v) sorbitol within 48 h. A very similar batch process performance with a product selectivity of 97% was achieved with potassium citrate buffered SBPP hydrolysate, demonstrating for the first time direct production of L-GalOA from hydrolyzed biomass using engineered S. cerevisiae. Combining the hydrolysis process of extracted SBPP and the biotransformation process with engineered S. cerevisiae paves the way towards repurposing pectin-rich residues as substrates for value-added chemicals. KEY POINTS: • Efficient bioreduction of D-GalA with S. cerevisiae in stirred-tank reactors • Batch production of L-GalOA by engineered S. cerevisiae with high selectivity • Direct L-GalOA production from hydrolyzed sugar beet press pulp Bioreduction of D-galacturonic acid to L-galactonate with recombinant Saccharomyces cerevisiae enables for the first time the valorization of hydrolysates from extracted sugar beet press pulp for the sustainable production of value-added chemicals.


Subject(s)
Beta vulgaris , Saccharomyces cerevisiae , Hexuronic Acids , Hydrolysis , Saccharomyces cerevisiae/genetics , Sugars
3.
Anaesthesist ; 67(12): 901-906, 2018 12.
Article in German | MEDLINE | ID: mdl-30367211

ABSTRACT

BACKGROUND: Whole-body computed tomography (CT) is increasingly being used as the diagnostic modality of choice in patients admitted to the resuscitation room. Beyond findings related to the suspected diagnosis it often additionally reveals incidental findings. The aim of this investigation was the evaluation of these findings in patients admitted via the emergency room after suffering potential major trauma or life-threatening medical conditions. Furthermore, the number of iatrogenic injuries as well as misplaced catheters and endotracheal tubes was investigated. METHODS: All patients admitted from 1 February 2012 to 31 January 2014 via the resuscitation area of the Mannheim University Medical Center, a tertiary care hospital and level 1 trauma center, were included in this study if they had undergone a whole-body CT scan at admission. Data from 1362 patients were collected retrospectively and 197 patients were excluded because of missing data so that the final cohort consisted of 1165 patients (1038 trauma and 127 internal neurological patients). Reports from the whole-body CT scans were screened for incidental findings. These findings were then classified as either clinically relevant or not. Furthermore, the reports were checked for iatrogenic injuries as well as misplaced catheters and endotracheal tubes. RESULTS: A total of 465 incidental findings were reported in 293 patients (25.1%) of the final cohort. In the synopsis of the radiological and clinical findings, 72 were rated as clinically relevant. In one patient two relevant incidental findings were reported and one patient presented with three incidental findings. In total, relevant incidental findings could be detected in 5.8% of the study patients (68/1165). In the discharge letters and/or the radiological report 16.2% of the incidental findings rated as clinically relevant were reported to be previously known, 66.2% were reported to be unknown and 17.6% could not be unequivocally classified as known or unknown due to missing references in the discharge letters. The group of internal neurological patients were clearly older than the trauma patients (61.6 years vs. 45.5 years). The rate of relevant incidental findings in the internal neurological group was more than twice as high as in the trauma group (11.0% vs. 5.2%); however, in the relatively young trauma group 1 in 20 patients showed an incidental finding classified as clinically relevant. In 43 (3.7%) patients a total of 46 iatrogenic injuries or misplaced catheters were reported. The most common finding was a too deeply placed endotracheal tube and five transurethral catheters placed in the emergency room were found to be blocked within the urethra. CONCLUSION: In addition to the main diagnosis, clinically relevant incidental findings were reported in nearly 25% of whole-body CT scans of patients admitted to the resuscitation room. Approximately 6% of patients had incidental findings rated as clinically relevant. In the internal neurological group of patients the rate of incidental findings was doubled compared to the trauma group; however, the latter were significantly younger. Whole-body CT was also useful for diagnosing iatrogenic injuries and misplaced catheters in approximately 4% of the study patients.


Subject(s)
Iatrogenic Disease , Incidental Findings , Resuscitation/methods , Tomography, X-Ray Computed/methods , Adolescent , Female , Germany , Humans , Male , Middle Aged , Resuscitation/statistics & numerical data , Retrospective Studies , Trauma Centers
4.
Brain Stimul ; 11(3): 600-606, 2018.
Article in English | MEDLINE | ID: mdl-29373260

ABSTRACT

BACKGROUND: Directional Deep Brain Stimulation (D-DBS) allows axially asymmetric electrical field shaping, away from structures causing side-effects. However, concerns regarding the impact on device lifespan and complexity of the monopolar survey have contributed to sparing use of these features. OBJECTIVE: To investigate whether chronically implanted D-DBS systems can improve the therapeutic window, without a negative impact on device lifespan, in thalamic deep brain stimulation (DBS). METHODS: We evaluated stable outcomes of initial programming sessions (4-6 weeks post-implantation) retrospectively in 8 patients with drug-resistant disabling tremor syndromes. We assessed the impact of directional stimulation on the Therapeutic Window (TW), Therapeutic Current Strength (TCS), tremor scores, disability scores and total electrical energy delivered. Finally, we performed Volume of Tissue Activation (VTA) modelling, based on a range of parameters. RESULTS: We report significant gains in TW (91%) and reductions in TCS (31%) with stimulation in the best direction compared to best omnidirectional stimulation alternative. Tremor and ADL scores improvements remained unchanged at six months. There was no increase in averaged IPG power consumption (there is a 6% reduction over the omnidirectional-only alternative). Illustrative VTA modelling shows that D-DBS achieves 85% of the total activation volume at just 69% of the stimulation amplitude of non-directional configuration. CONCLUSIONS: D-DBS can improve the therapeutic window over non-directional DBS, leading to significant reduction in disability that may be sustained without additional reprogramming visits. When averaged across the cohort, power output and predicted device lifespan was not impacted by the use of directional stimulation in this study.


Subject(s)
Deep Brain Stimulation/instrumentation , Deep Brain Stimulation/methods , Thalamus/physiology , Tremor/therapy , Aged , Electrodes, Implanted , Female , Humans , Male , Middle Aged , Models, Neurological , Retrospective Studies
5.
J Synchrotron Radiat ; 25(Pt 1): 145-150, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-29271764

ABSTRACT

The experimental observation of the depression effect in gas devices designed for X-ray free-electron lasers (FELs) is reported. The measurements were carried out at the Linac Coherent Light Source using a two-bunch FEL beam at 6.5 keV with 122.5 ns separation passing through an argon gas cell. The relative intensities of the two pulses of the two-bunch beam were measured, after and before the gas cell, from X-ray scattering off thin targets by using fast diodes with sufficient temporal resolution. At a cell pressure of 140 hPa, it was found that the after-to-before ratio of the intensities of the second pulse was about 17% ±â€…6% higher than that of the first pulse, revealing lower effective attenuation of the gas cell due to heating by the first pulse and subsequent gas density reduction in the beam path. This measurement is important in guiding the design and/or mitigating the adverse effects in gas devices for high-repetition-rate FELs such as the LCLS-II and the European XFEL or other future high-repetition-rate upgrades to existing FEL facilities.

6.
Phys Chem Chem Phys ; 19(15): 9974-9982, 2017 Apr 12.
Article in English | MEDLINE | ID: mdl-28362013

ABSTRACT

In situ X-ray absorption spectroscopy and mass spectrometry measurements were employed to simultaneously probe the atom specific short range order and reactivity of Pd and PtPd nanoparticles towards NO decomposition at 300 °C. The nanoparticles were synthesized by a well controlled, eco-friendly wet chemical reduction of metal salts and later supported on activated carbon. Particularly for the bimetallic PtPd samples, distinct atomic arrangements were achieved using a seeding growth method, which allowed producing a random nanoalloy, or nanoparticles with Pt- or Pd-rich core. X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction provided additional insights on their electronic, morphological and long range order structural properties. The results revealed that the higher the thermal induced atomic migration observed within the nanoparticles during thermal treatments, the least were their reactivity for NO abatement.

7.
Schmerz ; 31(1): 75-85, 2017 Feb.
Article in German | MEDLINE | ID: mdl-28091738

ABSTRACT

In the age of globalization and cultural diversification differing concepts of pain in patient care are of increasing importance. Historical models of the origin and interpretation of pain, which in this article are presented in a cursory and exemplary way, help to understand the panoply of modern concepts outside of medicine. Basically, pain was viewed not only in religion and philosophy but also by premodern physicians as a psychophysical phenomenon crucially depending on the determination by a "soul" therefore creating therapeutic options even before the discovery of an effective analgesia. Furthermore, the historical interpretations of pain in and outside of medicine can still be of profound importance to patients even today.


Subject(s)
Anthropology, Cultural/history , Cross-Cultural Comparison , Cultural Diversity , Ethics, Medical/history , Internationality/history , Pain Management/history , Pain/history , Religion and Medicine , History, 16th Century , History, 17th Century , History, 18th Century , History, 19th Century , History, 20th Century , History, 21st Century , History, Ancient , History, Medieval , Humans
8.
Phys Med Biol ; 59(22): 6959-77, 2014 Nov 21.
Article in English | MEDLINE | ID: mdl-25350552

ABSTRACT

Cardiac ablation procedures during electrophysiology interventions are performed under x-ray guidance with a C-arm imaging system. Some procedures require catheter navigation in complex anatomies like the left atrium. Navigation aids like 3D road maps and external tracking systems may be used to facilitate catheter navigation. As an alternative to external tracking a fully automatic method is presented here that enables the calculation of the 3D location of the ablation catheter from individual 2D x-ray projections. The method registers a high resolution, deformable 3D attenuation model of the catheter to a 2D x-ray projection. The 3D localization is based on the divergent beam projection of the catheter. On an individual projection, the catheter tip is detected in 2D by image filtering and a template matching method. The deformable 3D catheter model is adapted using the projection geometry provided by the C-arm system and 2D similarity measures for an accurate 2D/3D registration. Prior to the tracking and registration procedure, the deformable 3D attenuation model is automatically extracted from a separate 3D cone beam CT reconstruction of the device. The method can hence be applied to various cardiac ablation catheters. In a simulation study of a virtual ablation procedure with realistic background, noise, scatter and motion blur an average 3D registration accuracy of 3.8 mm is reached for the catheter tip. In this study four different types of ablation catheters were used. Experiments using measured C-arm fluoroscopy projections of a catheter in a RSD phantom deliver an average 3D accuracy of 4.5 mm.


Subject(s)
Cardiac-Gated Imaging Techniques/methods , Catheter Ablation/methods , Heart/diagnostic imaging , Heart/physiology , Imaging, Three-Dimensional/methods , Phantoms, Imaging , Computer Simulation , Cone-Beam Computed Tomography/methods , Fluoroscopy/methods , Humans , Motion , X-Rays
9.
Phys Med Biol ; 59(14): 3861-75, 2014 Jul 21.
Article in English | MEDLINE | ID: mdl-24957596

ABSTRACT

Cardiac C-arm CT imaging delivers a tomographic region-of-interest reconstruction of the patient's heart during image guided catheter interventions. Due to the limited size of the flat detector a volume image is reconstructed, which is truncated in the cone-beam (along the patient axis) and the fan-beam (in the transaxial plane) direction. To practically address this local tomography problem correction methods, like projection extension, are available for first pass image reconstruction. For second pass correction methods, like metal artefact reduction, alternative correction schemes are required when the field of view is limited to a region-of-interest of the patient. In classical CT imaging metal artefacts are corrected by metal identification in a first volume reconstruction and generation of a corrected projection data set followed by a second reconstruction. This approach fails when the metal structures are located outside the reconstruction field of view. When a C-arm CT is performed during a cardiac intervention pacing leads and other cables are frequently positioned on the patients skin, which results in propagating streak artefacts in the reconstruction volume. A first pass approach to reduce this type of artefact is introduced and evaluated here. It makes use of the fact that the projected position of objects outside the reconstruction volume changes with the projection perspective. It is shown that projection based identification, tracking and removal of high contrast structures like cables, only detected in a subset of the projections, delivers a more consistent reconstruction volume with reduced artefact level. The method is quantitatively evaluated based on 50 simulations using cardiac CT data sets with variable cable positioning. These data sets are forward projected using a C-arm CT system geometry and generate artefacts comparable to those observed in clinical cardiac C-arm CT acquisitions. A C-arm CT simulation of every cardiac CT data set without cables served as a ground truth. The 3D root mean square deviation between the simulated data set with and without cables could be reduced for 96% of the simulated cases by an average of 37% (min -9%, max 73%) when using the first pass correction method. In addition, image quality improvement is demonstrated for clinical whole heart C-arm CT data sets when the cable removal algorithm was applied.


Subject(s)
Artifacts , Cone-Beam Computed Tomography , Heart/diagnostic imaging , Image Processing, Computer-Assisted/methods , Humans , Metals , Models, Biological
10.
J Anim Sci ; 92(1): 349-58, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24305871

ABSTRACT

Monitoring the nutritional status of range cows is difficult. Near-infrared spectroscopy (NIRS) of feces has been used to predict diet quality in cattle. When fecal NIRS is coupled with decision support software such as the Nutritional Balance Analyzer (NUTBAL PRO), nutritional status and animal performance can be monitored. Approximately 120 Hereford and 90 CGC composite (50% Red Angus, 25% Tarentaise, and 25% Charolais) cows grazing in a single herd were used in a study to determine the ability of fecal NIRS and NutbalPro to project BCS (1 = thin and 9 = fat) under commercial scale rangeland conditions in central Arizona. Cattle were rotated across the 31,000 ha allotment at 10 to 20 d intervals. Cattle BCS and fecal samples (approximately 500 g) composited from 5 to 10 cows were collected in the pasture approximately monthly at the midpoint of each grazing period. Samples were frozen and later analyzed by NIRS for prediction of diet crude protein (CP) and digestible organic matter (DOM). Along with fecal NIRS predicted diet quality, animal breed type, reproductive status, and environmental conditions were input to the software for each fecal sampling and BCS date. Three different evaluations were performed. First, fecal NIRS and NutbalPro derived BCS was projected forward from each sampling as if it were a "one-time only" measurement. Second, BCS was derived from the average predicted weight change between 2 sampling dates for a given period. Third, inputs to the model were adjusted to better represent local animals and conditions. Fecal NIRS predicted diet quality varied from a minimum of approximately 5% CP and 57% DOM in winter to a maximum of approximately 11% CP and 60% DOM in summer. Diet quality correlated with observed seasonal changes and precipitation events. In evaluation 1, differences in observed versus projected BCS were not different (P > 0.1) between breed types but these values ranged from 0.1 to 1.1 BCS in Herefords and 0.0 to 0.9 in CGC. In evaluation 2, differences in observed versus projected BCS were not different (P > 0.1) between breed types but these values ranged from 0.00 to 0.46 in Hereford and 0.00 to 0.67 in CGC. In evaluation 3, the range of differences between observed and projected BCS was 0.04 to 0.28. The greatest difference in projected versus observed BCS occurred during periods of lowest diet quality. Body condition was predicted accurately enough to be useful in monitoring the nutrition of range beef cows under the conditions of this study.


Subject(s)
Animal Husbandry/methods , Cattle/physiology , Decision Support Techniques , Nutritional Status , Spectroscopy, Near-Infrared/methods , Animal Nutritional Physiological Phenomena , Animals , Arizona , Body Composition , Desert Climate , Feces/chemistry , Female , Male , Spectroscopy, Near-Infrared/veterinary
11.
Dtsch Med Wochenschr ; 138(51-52): 2671-7, 2013 Dec.
Article in German | MEDLINE | ID: mdl-24343185

ABSTRACT

For very long medicine has been dealing with the question what death means and when it has occurred. The promotion of this debate is mainly owed to the new medical findings and the concrete requirements of the clinical practice; but other factors like social-historical influences (in particular the dispute over the secure determination of death) as well as the (de-)medicalization of the concept of death have also to be taken into account. In a concise historical overlook this study aims to demonstrate the development of the definition of death: In ancient Greece Aristotle, disregarding the transcendent teleology, describes the natural or non-natural death that occurs when the production of the vegetative warmth in the central organ - the heart - has ceased. In the Enlightenment Johann August Unzer (emulated later by Bichat and Hufeland) worked out the concept of the step-by-step process of death: In the attempt to explain sudden death, apparent death and reanimation the enlightened physiologist differentiated between the cessation of the senses (caused by heart death and brain death) and the vegetative functions. In the second half of the 20th century progress made in transplanting and intensive care generated a broadened medical definition of death that met strong opposition in the discussions on the autonomy of the patient and the worth of human life. Generally considered, the increasing differences in interpreting death between physicians and medical laymen, but also in medical practice and basic research are mainly due to the divergent demands regarding the definition and diagnosis of death.


Subject(s)
Brain Death/diagnosis , Death , Forensic Medicine/history , Philosophy, Medical/history , Terminology as Topic , History, 15th Century , History, 16th Century , History, 17th Century , History, 18th Century , History, 19th Century , History, 20th Century , History, 21st Century , History, Ancient , History, Medieval
13.
Rhinology ; 51(1): 61-9, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23441313

ABSTRACT

BACKGROUND: Hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) is often associated with chronic rhinosinusitis (CRS), nasal polyps (CRSwNP) and asthma, together known as Samter's triad. The disease is characterised by eicosanoid imbalance. In our study, we determined clinical and laboratory parameters in respect of three groups of patients: 1) CRSwNP, 2) CRSwNP and asthma (CRSwNP-A), and 3) CRSwNP with asthma and NSAID-triggered hypersensitivity (CRSwNP-AA). Our main goal was to improve the characterisation of the stages of development in Samter's triad, pointing to the homogeneous or heterogeneous course of disease. METHODOLOGY: Forty-three patients (10 CRSwNP, 14 CRSwNP-A, 19 CRSwNP-AA) and 10 control subjects were included in the study. Nasal assessment using the CRS visual analogue score, endoscopy- and computer tomography scores, allergy tests, analysis of sinus surgeries, asthma severity and in vitro functional eicosanoid tests (FET) with peripheral blood leucocytes were performed. RESULTS: The scores reflecting CRS symptoms such as nasal congestion, nasal discharge and smell impairment differed between the patients groups reflecting the severity of disease (CRSwNP-AA > CRSwNP-A > CRSwNP). Eicosanoid imbalance correlated with nasal congestion, nasal discharge and loss of smell. CONCLUSION: The data presented support the hypothesis of the continuous development of NSAID-triggered hypersensitivity, culminating in Samter's triad.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Asthma/chemically induced , Drug Hypersensitivity/immunology , Eicosanoids/blood , Nasal Polyps/chemically induced , Rhinitis/chemically induced , Sinusitis/chemically induced , Adult , Aged , Anti-Inflammatory Agents, Non-Steroidal/immunology , Asthma/complications , Asthma/immunology , Case-Control Studies , Chi-Square Distribution , Eicosanoids/immunology , Endoscopy , Female , Humans , Male , Middle Aged , Nasal Polyps/complications , Nasal Polyps/immunology , Rhinitis/complications , Rhinitis/immunology , Severity of Illness Index , Sinusitis/complications , Sinusitis/immunology , Statistics, Nonparametric , Surveys and Questionnaires , Tomography, X-Ray Computed
14.
Anal Bioanal Chem ; 405(11): 3739-52, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23435451

ABSTRACT

The review covers recent developments in which quantum dots (QDs) are combined with electrodes for detection of analytes. Special focus will be on the generation of photocurrents and the possibility of spatially resolved, light-directed analysis. Different modes for combining biochemical reactions with QDs will be discussed. Other applications involve the use of QDs as labels in binding analysis. Different methods have been developed for read-out. In addition to photocurrent analysis, voltammetric detection of metals and electrochemiluminescence (ECL) can be used. In the latter, light is the sensor signal. ECL-based systems combine the advantage of very sensitive analytical detection with rather simple instrumentation.


Subject(s)
Biosensing Techniques/instrumentation , Electrochemical Techniques/instrumentation , Luminescent Measurements/instrumentation , Quantum Dots , Animals , Biosensing Techniques/methods , Electrochemical Techniques/methods , Electrodes , Equipment Design , Humans , Luminescent Measurements/methods , Models, Molecular
16.
Anal Bioanal Chem ; 404(3): 843-51, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22722745

ABSTRACT

Francisella tularensis are very small, gram-negative bacteria which are capable of infecting a number of mammals. As a highly pathogenic species, it is a potential bioterrorism agent. In this work we demonstrate a fast immunological detection system for whole F. tularensis bacteria. The technique is based on a quartz crystal microbalance with dissipation monitoring (QCMD), which uses sensor chips modified by a specific antibody. This antibody is useful as a capture molecule to capture the lipopolysaccharide structure on the surface of the bacterial cell wall. The QCMD technique is combined with a microfluidic system and allows the label-free online detection of the binding of whole bacteria to the sensor surface in a wide dynamic concentration range. A detection limit of about 4 × 10(3) colony-forming units per milliliter can be obtained. Furthermore, a rather short analysis time and a clear discrimination against other bacteria can be achieved. Additionally, we demonstrate two possibilities for specific and significant signal enhancement by using antibody-functionalized gold nanoparticles or an enzymatic precipitation reaction. These additional steps can be seen as further proof of the specificity and validity.


Subject(s)
Antibodies, Immobilized/chemistry , Biosensing Techniques , Francisella tularensis/isolation & purification , Lipopolysaccharides/chemistry , Quartz Crystal Microbalance Techniques/methods , Antibodies, Immobilized/immunology , Francisella tularensis/chemistry , Francisella tularensis/immunology , Gold/chemistry , Limit of Detection , Metal Nanoparticles/chemistry , Microfluidic Analytical Techniques , Quartz Crystal Microbalance Techniques/instrumentation , Stem Cells
17.
Clin Genet ; 82(5): 478-83, 2012 Nov.
Article in English | MEDLINE | ID: mdl-21919902

ABSTRACT

In families with clustering of breast and ovarian cancer, molecular testing of the major susceptibility genes BRCA1/2 helps to identify patients with disease mutations and healthy persons at high risk who can participate in targeted intervention programs. We investigated 5559 families from the German Consortium for Hereditary Breast and Ovarian Cancer included between 1997 and 2008 and treated under clinical routine conditions. In each family an index patient/person had been screened for deleterious mutations in BRCA1/2. Healthy relatives agreed to predictive testing in 888 of 1520 BRCA1/2 mutation-positive families (58%). Of 2646 eligible unaffected first-degree relatives 1143 decided to be tested (43%). In 325 families with BRCA1/2-positive index patients one related BC/OC patient was tested and 39 (12.0%; 95% confidence interval: 8.7-16.0%) discrepant cases found. A second related individual was screened in 163 of 3388 (4.9%) families with BRCA1/2-negative index patient and in eight families a BRCA1/2 mutation was found. In BRCA1/2 mutation-positive families, BC/OC patients lacking the familial mutation have to be expected at a rather high rate. In families with BRCA1/2-negative index patient we recommend a second screening if another patient with a high probability of carrying a BRCA1/2 mutation is available.


Subject(s)
BRCA2 Protein/genetics , Genetic Testing , Ubiquitin-Protein Ligases/genetics , Adult , Aged , Breast Neoplasms/genetics , Female , Genetic Predisposition to Disease , Germany , Humans , Middle Aged , Mutation , Ovarian Neoplasms/genetics , Pedigree , Phenotype , Risk Factors
18.
Handchir Mikrochir Plast Chir ; 43(6): 376-83, 2011 Dec.
Article in German | MEDLINE | ID: mdl-22095056

ABSTRACT

Microsurgery is a very relevant component of reconstructive surgery. In this context anticoagulation plays an increasing role. At the moment there are no unanimously accepted prospective studies or generally accepted regimes available that could serve as evidence-based guidelines for the prevention of thrombosis in microsurgery. With regard to this problem the aim of a series of workshops during the annual meetings of the German-speaking group for microsurgery in 2009 and 2010 was to establish a first possible consensus. This article reflects the main aspects of the ongoing development of a generally acceptable guideline for anticoagulation in microsurgery as interim report of these consensus workshops. Basically there are 3 main agents in thromboprophylaxis available: antiplatelet drugs, dextran and heparin. In the course of the workshops no general use of aspirin or dextran for anticoagulation in microsurgery was recommended. The use of heparin as anticoagulation agent is advisable for different indications. Low molecular heparins (LMH) have certain advantages in comparison to unfractionated heparins (UFH) and are therefore preferred by most participants. Indications for UFH are still complex microsurgical revisions, renal failure and some specific constellations in patients undergoing reconstruction of the lower extremity, where the continuous administration of heparin is recommended. At the moment of clamp release a single-shot of UFH is still given by many microsurgeons, despite a lack of scientific evidence. Future prospective clinical trials and the establishment of a generally accepted evidence-based guideline regarding anticoagulation treatment in microsurgery are deemed necessary.


Subject(s)
Anticoagulants/administration & dosage , Education , Microsurgery/standards , Microvessels/surgery , Perioperative Care/standards , Peripheral Nerves/surgery , Evidence-Based Medicine , Germany , Humans , Partial Thromboplastin Time , Postoperative Complications/blood , Postoperative Complications/prevention & control , Thrombosis/blood , Thrombosis/prevention & control
19.
Anal Chem ; 83(20): 7778-85, 2011 Oct 15.
Article in English | MEDLINE | ID: mdl-21870859

ABSTRACT

This study reports on the oxygen sensitivity of quantum dot electrodes modified with CdSe/ZnS nanocrystals. The photocurrent behavior is analyzed for dependence on pH and applied potential by potentiostatic and potentiodynamic measurements. On the basis of the influence of the oxygen content in solution on the photocurrent generation, the enzymatic activity of glucose oxidase is evaluated in solution. In order to construct a photobioelectrochemical sensor which can be read out by illuminating the respective electrode area, two different immobilization methods for the fixation of the biocatalyst have been investigated. Both covalent cross-linking and layer-by-layer deposition of GOD by means of the polyelectrolyte polyallylamine hydrochloride show that a sensor construction is possible. The sensing properties of this type of electrode are drastically influenced by the amount and density of the enzyme on top of the quantum dot layer, which can be advantageously adjusted by the layer-by-layer technique. By depositing four bilayers [GOD/PAH](4) on the CdSe/ZnS electrode, a fast-responding sensor for the concentration range of 0.1-5 mM glucose can be prepared. This study opens the door to multianalyte detection with a nonstructured sensing electrode, localized enzymes, and spatial read-out by light.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Light , Quantum Dots , Cadmium Compounds/chemistry , Electrodes , Glucose/analysis , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Immobilized Proteins/chemistry , Immobilized Proteins/metabolism , Oxygen/chemistry , Polyamines/chemistry , Selenium Compounds/chemistry , Sulfides/chemistry , Zinc Compounds/chemistry
20.
Surf Coat Technol ; 205(12-7): 3729-3735, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-22241938

ABSTRACT

The manipulation of mechanical and thermal interfaces is essential for the design of modern composites. Amongst these are copper carbon composites which can exhibit excellent heat conductivities if the Cu/C interface is affected by a suitable interlayer to minimize the Thermal Contact Resistance (TCR) and to maximize the adhesion strength between Cu and C.In this paper we report on the effect of boron based interlayers on wetting, mechanical adhesion and on the TCR of Cu coatings deposited on glassy carbon substrates by magnetron sputtering. The interlayers were 5 nm thick and consisted of pure B and B with additions of the carbide forming metals Mo, Ti and Cr in the range of 5 at.% relative to B. The interlayers were deposited by RF magnetron sputtering from either a pure B target or from a composite target. The interlayer composition was checked by Auger Electron Spectroscopy and found to be homogenous within the whole film.The system C-substrate/interlayer/Cu coating was characterized in as deposited samples and samples heat treated for 30 min at 800 °C under High Vacuum (HV), which mimics typical hot pressing parameters during composite formation. Material transport during heat treatment was investigated by Secondary Ion Mass Spectroscopy (SIMS). The de-wetting and hole formation in the Cu coating upon heat treatment were studied by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The adhesion of the Cu coating was evaluated by mechanical pull-off testing. The TCR was assessed by infrared photothermal radiometry (PTR). A correlation between the adhesion strength and the value of the TCR which was measured by PTR was determined for as deposited as well as for heat treated samples.

SELECTION OF CITATIONS
SEARCH DETAIL
...