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1.
Life Sci Space Res (Amst) ; 20: 62-71, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30797435

ABSTRACT

Extended human spaceflight missions require not only the processing, but also the recycling of human waste streams in bio-regenerative life support systems, which are rich in valuable resources. The Combined Regenerative Organic food Production® project of the German Aerospace Center aims for recycling human metabolic waste products to produce useful resources. A biofiltration process based on natural communities of microorganisms has been developed and tested. The processed aqueous solution is, among others, rich in nitrogen present as nitrate. Nitrate is one of the main nutrients required for plant cultivation, resulting in strong synergies between the developed recycling process and plant cultivation. The latter is envisaged as the basis of future bio-regenerative life support systems, because plants do consume carbon dioxide, water and nutrients in order to produce oxygen, water, food and inedible biomass. This paper describes a series of plant cultivation experiments performed with synthetic urine processed in a bioreactor. The aim of the experiments was to investigate the feasibility of growing tomato plants with this solution. The results of the experiments show that such cultivation of tomato plants is generally feasible, but that the plants are less productive. The fruit fresh weight per plant is less compared to plants grown with the half-strength Hoagland reference solution. This lack in production is caused by imbalances of sodium, chloride, potassium, magnesium and ammonium in the solution gained from recycling the synthetic urine. An attempt on adjusting the produced bioreactor solution with additional mineral fertilizers did not show a significant improvement in crop yield.


Subject(s)
Biomimetic Materials/chemistry , Ecological Systems, Closed , Nutrients/pharmacology , Plant Development , Solanum lycopersicum/growth & development , Urine/chemistry , Waste Management/methods , Humans , Solanum lycopersicum/drug effects , Space Flight
3.
Life Sci Space Res (Amst) ; 10: 1-16, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27662782

ABSTRACT

The cultivation of higher plants occupies an essential role within bio-regenerative life support systems. It contributes to all major functional aspects by closing the different loops in a habitat like food production, CO2 reduction, O2 production, waste recycling and water management. Fresh crops are also expected to have a positive impact on crew psychological health. Plant material was first launched into orbit on unmanned vehicles as early as the 1960s. Since then, more than a dozen different plant cultivation experiments have been flown on crewed vehicles beginning with the launch of Oasis 1, in 1971. Continuous subsystem improvements and increasing knowledge of plant response to the spaceflight environment has led to the design of Veggie and the Advanced Plant Habitat, the latest in the series of plant growth systems. The paper reviews the different designs and technological solutions implemented in higher plant flight experiments. Using these analyses a comprehensive comparison is compiled to illustrate the development trends of controlled environment agriculture technologies in bio-regenerative life support systems, enabling future human long-duration missions into the solar system.


Subject(s)
Ecological Systems, Closed , Environment, Controlled , Plant Development , Space Flight , Humans
4.
Physiol Meas ; 37(6): 698-712, 2016 06.
Article in English | MEDLINE | ID: mdl-27203725

ABSTRACT

The measurement of rapid regional lung volume changes by electrical impedance tomography (EIT) could determine regional lung function in patients with obstructive lung diseases during pulmonary function testing (PFT). EIT examinations carried out before and after bronchodilator reversibility testing could detect the presence of spatial and temporal ventilation heterogeneities and analyse their changes in response to inhaled bronchodilator on the regional level. We examined seven patients suffering from chronic asthma (49 ± 19 years, mean age ± SD) using EIT at a scan rate of 33 images s(-1) during tidal breathing and PFT with forced full expiration. The patients were studied before and 5, 10 and 20 min after bronchodilator inhalation. Seven age- and sex-matched human subjects with no lung disease history served as a control study group. The spatial heterogeneity of lung function measures was quantified by the global inhomogeneity indices calculated from the pixel values of tidal volume, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak flow and forced expiratory flow between 25% and 75% of FVC as well as histograms of pixel FEV1/FVC values. Temporal heterogeneity was assessed using the pixel values of expiration times needed to exhale 75% and 90% of pixel FVC. Regional lung function was more homogeneous in the healthy subjects than in the patients with asthma. Spatial and temporal ventilation distribution improved in the patients with asthma after the bronchodilator administration as evidenced mainly by the histograms of pixel FEV1/FVC values and pixel expiration times. The examination of regional lung function using EIT enables the assessment of spatial and temporal heterogeneity of ventilation distribution during bronchodilator reversibility testing. EIT may become a new tool in PFT, allowing the estimation of the natural disease progression and therapy effects on the regional and not only global level.


Subject(s)
Asthma/diagnostic imaging , Bronchodilator Agents/therapeutic use , Lung/diagnostic imaging , Respiratory Function Tests/methods , Tomography/methods , Asthma/drug therapy , Asthma/physiopathology , Electric Impedance , Female , Humans , Lung/drug effects , Lung/physiopathology , Male , Middle Aged , Pilot Projects , Time Factors
5.
Pneumologie ; 70(4): 250-76, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27064418

ABSTRACT

Non-tuberculous mycobacterioses comprise a group of diseases caused by mycobacteria which do not belong to the Mycobacterium (M.) tuberculosis-complex and are not ascribed to M. leprae. These mycobacteria are characterized by a broad variety as to environmental distribution and adaptation. Some of the species may cause specific diseases, especially in patients with underlying immunosuppressive diseases, chronic pulmonary diseases or genetic predisposition, respectively. Worldwide, a rising prevalence and significance of non-tuberculous mycobacterioses is recognized. The present recommendations summarise current aspects of epidemiology, pathogenesis, clinical aspects, diagnostics - especially microbiological methods including susceptibility testing -, and specific treatment for the most relevant species. Diagnosis and treatment of non-tuberculous mycobacterioses during childhood and in HIV-infected individuals are described in separate chapters.


Subject(s)
Diagnostic Techniques, Respiratory System/standards , Infectious Disease Medicine/standards , Mycobacterium Infections, Nontuberculous/diagnosis , Mycobacterium Infections, Nontuberculous/therapy , Practice Guidelines as Topic , Pulmonary Medicine/standards , Evidence-Based Medicine , Germany , Humans , Mycobacterium Infections, Nontuberculous/microbiology , Treatment Outcome
7.
Diagn Pathol ; 10: 130, 2015 Jul 28.
Article in English | MEDLINE | ID: mdl-26215852

ABSTRACT

BACKGROUND: Several c-MET targeting inhibitory molecules have already shown promising results in the treatment of patients with Non-small Cell Lung Cancer (NSCLC). Combination of EGFR- and c-MET-specific molecules may overcome EGFR tyrosine kinase inhibitor (TKI) resistance. The aim of this study was to allow for the identification of patients who might benefit from TKI treatments targeting MET and to narrow in on the diagnostic assessment of MET. METHODS: 222 tumor tissues of patients with NSCLC were analyzed concerning c-MET expression and activation in terms of phosphorylation (Y1234/1235 and Y1349) using a microarray format employing immunohistochemistry (IHC). Furthermore, protein expression and MET activation was correlated with the amplification status by Fluorescence in Situ Hybridization (FISH). RESULTS: Correlation was observed between phosphorylation of c-MET at Y1234/1235 and Y1349 (spearman correlation coefficient rs = 0.41; p < 0.0001). No significant correlation was shown between MET expression and phosphorylation (p > 0.05). c-MET gene amplification was detected in eight of 214 patients (3.7%). No significant association was observed between c-MET amplification, c-MET protein expression and phosphorylation. CONCLUSION: Our data indicate, that neither expression of c-MET nor the gene amplification status might be the best way to select patients for MET targeting therapies, since no correlation with the activation status of MET was observed. We propose to take into account analyzing the phosphorylation status of MET by IHC to select patients for MET targeting therapies. Signaling of the receptor and the activation of downstream molecules might be more crucial for the benefit of therapeutics targeting MET receptor tyrosine kinases than expression levels alone.


Subject(s)
Carcinoma, Non-Small-Cell Lung/drug therapy , Gene Amplification , Gene Expression Regulation, Neoplastic , Lung Neoplasms/drug therapy , Molecular Targeted Therapy/methods , Patient Selection , Proto-Oncogene Proteins c-met/metabolism , Aged , Antineoplastic Agents/therapeutic use , Blotting, Western , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Female , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Male , Middle Aged , Phosphorylation , Proto-Oncogene Proteins c-met/genetics , Real-Time Polymerase Chain Reaction , Retrospective Studies , Tissue Array Analysis
8.
Pneumologie ; 67(11): 605-33, 2013 Nov.
Article in German | MEDLINE | ID: mdl-24198237

ABSTRACT

Nontuberculous mycobacterioses comprise a group of diseases caused by mycobacteria which do not belong to the Mycobacterium (M.) tuberculosis complex and are not ascribed to M. leprae. These mycobacteria are characterized by a broad variety as to environmental distribution and adaptation. Some of the species may cause specific diseases, especially in patients with underlying immunosuppressive diseases, chronic pulmonary diseases or genetic predisposition, respectively. Worldwide a rising prevalence and significance of nontuberculous mycobacterioses can be recognized. The present recommendations summarise actual aspects of epidemiology, pathogenesis, clinical aspects, diagnostics - especially microbiological methods including susceptibility testing -, and specific treatment for the most relevant species. Diagnosis and treatment of nontuberculous mycobacterioses during childhood and in HIV-infected individuals are described in separate chapters.


Subject(s)
Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium Infections, Nontuberculous/prevention & control , Nontuberculous Mycobacteria , Practice Guidelines as Topic , Pulmonary Medicine/standards , Anti-Bacterial Agents , Germany , Humans
9.
Pneumologie ; 67(2): 81-111, 2013 Feb.
Article in German | MEDLINE | ID: mdl-23325398

ABSTRACT

Idiopathic pulmonary fibrosis is a fatal lung disease with a variable and unpredictable natural history and limited treatment options. Since publication of the ATS-ERS statement on IPF in the year 2000 diagnostic standards have improved and a considerable number of randomized controlled treatment trials have been published necessitating a revision. In the years 2006 - 2010 an international panel of IPF experts produced an evidence-based guideline on diagnosis and treatment of IPF, which was published in 2011. In order to implement this evidence-based guideline into the German Health System a group of German IPF experts translated and commented the international guideline, also including new publications in the field. A consensus conference was held in Bochum on December 3rd 2011 under the protectorate of the "Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin (DGP)" and supervised by the "Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften" (AWMF). Most recommendations of the international guideline were found to be appropriate for the german situation. Based on recent clinical studies "weak negative" treatment recommendations for pirfenidone and anticoagulation were changed into "weak positive" for pirfenidone and "strong negative" for anticoagulation. Based on negative results from the PANTHER-trial the recommendation for the combination therapy of prednisone plus azathiorpine plus N-acetlycsteine was also changed into strong negative für patients with definite IPF. This document summarizes essential parts of the international IPF guideline and the comments and recommendations of the German IPF consensus conference.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Idiopathic Pulmonary Fibrosis/diagnosis , Idiopathic Pulmonary Fibrosis/therapy , Practice Guidelines as Topic , Pulmonary Medicine/standards , Tomography, X-Ray Computed/methods , Germany , Humans , Idiopathic Pulmonary Fibrosis/blood , Internationality
11.
Respiration ; 83(1): 61-73, 2012.
Article in English | MEDLINE | ID: mdl-21860221

ABSTRACT

BACKGROUND: The acute-phase protein haptoglobin (Hp) and its receptor CD163 serve as immunomodulators and possess anti-inflammatory besides antioxidant functions. OBJECTIVES: To further understand the role of the recently described pulmonary Hp (pHp) and its receptor CD163 in case of inflammation and infection, pHp and CD163 were investigated on mRNA and protein level to gain insight into the cellular events taking place upon stimulation with the inflammatory mediators LPS, Pam3, cytokine IL-6 and dexamethasone, and upon infection with respiratory pathogens (Haemophilus influenzae, Streptococcuspneumoniae and Chlamydia pneumoniae) by use of a human ex vivo tissue culture model and cell cultures of A549 and alveolar epithelial cells type II. In addition, pHp and CD163 expression in COPD and sarcoidosis was assessed. METHODS: We conducted experiments using 942 ex vivo cultured lung samples applying immunohistochemistry, immunocytochemistry, in situ hybridization, immunofluorescence, real-time PCR, RT-PCR, slot and Western immunoblot analyses with tissue lysates and culture supernatants as well as ELISA and cytometric bead array analyses. RESULTS: This study describes for the first time the expression, regulation and secretion of pHp and its receptor CD163 in the human lung. The release of soluble mediators from A549 cell line and human monocyte-derived macrophages was observed indicating that Hp differentially activates the release of soluble mediators and major chemoattractants. CONCLUSIONS: The findings indicate a native function of pHp and CD163 as functional pulmonary defense elements due to local expression, regulation and secretion during lung infection and as part of the inflammatory immune response of the respiratory system.


Subject(s)
Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Cytokines/metabolism , Haptoglobins/metabolism , Inflammation Mediators/metabolism , Lung/metabolism , Pulmonary Disease, Chronic Obstructive/metabolism , Receptors, Cell Surface/metabolism , Respiratory Tract Infections/metabolism , Antigens, CD/genetics , Antigens, Differentiation, Myelomonocytic/genetics , Blotting, Western , Cell Line , Cytokines/genetics , Enzyme-Linked Immunosorbent Assay , Humans , Immunohistochemistry , Lung/pathology , RNA/analysis , Real-Time Polymerase Chain Reaction , Receptors, Cell Surface/genetics , Receptors, Scavenger
12.
Br J Cancer ; 105(5): 673-81, 2011 Aug 23.
Article in English | MEDLINE | ID: mdl-21811254

ABSTRACT

BACKGROUND: Different therapy regimens in non-small-cell lung cancer (NSCLC) are of rising clinical importance, and therefore a clear-cut subdifferentiation is mandatory. The common immunohistochemical markers available today are well applicable for subdifferentiation, but a fraction of indistinct cases still remains, demanding upgrades of the panel by new markers. METHODS: We report here the generation and evaluation of a new monoclonal antibody carrying the MAdL designation, which was raised against primary isolated human alveolar epithelial cells type 2. RESULTS: Upon screening, one clone (MAdL) was identified as a marker for alveolar epithelial cell type II, alveolar macrophages and adenocarcinomas of the lung. In a large-scale study, this antibody, with an optimised staining procedure for formalin-fixed tissues, was then evaluated together with the established markers thyroid transcription factor-1, surfactant protein-A, pro-surfactant protein-B and napsin A in a series of 362 lung cancer specimens. The MAdL displays a high specificity (>99%) for adenocarcinomas of the lung, together with a sensitivity of 76.5%, and is capable of delivering independent additional diagnostic information to the established markers. CONCLUSION: We conclude that MAdL is a new specific marker for adenocarcinomas of the lung, which helps to clarify subdifferentiation in a considerable portion of NSCLCs.


Subject(s)
Adenocarcinoma/diagnosis , Antibodies, Monoclonal/biosynthesis , Antibodies, Monoclonal/metabolism , Biomarkers, Tumor , Lung Neoplasms/diagnosis , Adenocarcinoma/metabolism , Adenocarcinoma of Lung , Animals , Antibodies, Monoclonal/analysis , Antibody Formation , Antibody Specificity , Biomarkers, Tumor/analysis , Biomarkers, Tumor/biosynthesis , Biomarkers, Tumor/metabolism , Carcinoma, Non-Small-Cell Lung/classification , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cross Reactions , Early Detection of Cancer/methods , Female , Humans , Lung Neoplasms/classification , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Mice, Inbred BALB C , Neoplasm Staging , Sensitivity and Specificity , Tissue Array Analysis
14.
Pneumologie ; 65(9): 558-64, 2011 Sep.
Article in German | MEDLINE | ID: mdl-21512973

ABSTRACT

BACKGROUND: The purpose of this retrospective study was to investigate the efficacy and safety of an indwelling pleural device (PleurX, Denver Biomedical, USA) for the treatment of recurrent pleural effusions. In cases when life expectancy tends to be very short and also surgical decortication is not recommended, pleurodesis is another treatment option but requires complete drainage of the whole pleural fluid for optimal results which is sometimes hard to achieve. The PleurX catheter is an alternative therapeutic option. METHODS AND RESULTS: We retrospectively analysed the clinical data from a total of 21 patients who were treated with a PleurX alone (11 patients) or who initially received pleurodesis and afterwards a PleurX catheter (10 patients). Mean survival was 25 weeks after initial diagnosis of the underlying disease. The mean amount of pleural effusion drained per week was 725 mL. 16 patients used the catheter until they died at least 1 - 2 times a week. The complication rate was 19 % and thus within a reasonable range when compared to other treatment options for recurrent pleural effusions. There was no statistically significant difference in clinical outcome in both groups (pleurodesis and subsequent PleurX vs. PleurX alone). The amount of evacuated pleural effusion was inversely correlated with the remaining life time. CONCLUSION: The use of an indwelling pleural device is a safe alternative treatment option for patients with chronic pleural effusions and trapped lung signs. We should be aware of this device and propagate its use at an earlier stage of malignant diseases with recurrent pleural effusions, especially when the remaining life time is short.


Subject(s)
Chest Tubes , Pleural Effusion, Malignant/therapy , Pleural Effusion/therapy , Aged , Aged, 80 and over , Female , Hospital Mortality , Humans , Male , Middle Aged , Pleural Effusion/mortality , Pleural Effusion, Malignant/mortality , Pleurodesis , Recurrence , Retrospective Studies , Survival Rate
17.
Rom J Morphol Embryol ; 51(4): 647-53, 2010.
Article in English | MEDLINE | ID: mdl-21103621

ABSTRACT

Despite considerable progress in the development of individualized targeted therapies of tumor diseases, identification of additional reliable target molecules is still mandatory. One of the most recent targets is microtubule-associated human EML4 generating a fusion-type oncogene with ALK demonstrating marked transforming activity in lung cancer. Since EML4 is a poorly characterized protein with regard to expression, function and regulation in human tissue, specimens of human tumor and tumor-free tissues obtained from patients with NSCLC were analyzed to determine the cellular localization. All tissue samples have been previously fixed with the novel HOPE-technique and paraffin embedded. Determination of both gene expression and protein levels of EML4 were performed using RT-PCR, in situ hybridization as well as immunohistochemistry, respectively. In human NSCLC tissue samples, possible regulation of EML4 transcription upon chemotherapy with combinations of most established cytotoxic drugs for NSCLC treatment was also studied employing the recently established ex vivo tissue culture model STST. In normal lung, both marked mRNA and protein levels of EML4 were localized in alveolar macrophages. In contrast, lung tumor tissues always showed consistent transcriptional expression in situ and by RT-PCR. Stimulation of NSCLC tissues with chemotherapeutics revealed heterogeneous effects on EML4 mRNA levels. Based on its expression patterns in both tumor-free lung and NSCLC tissues, human EML4 is likely to be closely associated with processes involved in local inflammation of the lung as well as with tumor behavior. Thus, our results suggest that EML4 may have the potential as a therapeutic target molecule in NSCLC chemotherapy.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung/metabolism , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Line, Tumor , Gene Expression/drug effects , Humans , Lung Neoplasms/drug therapy
18.
Ultraschall Med ; 31(1): 53-62, 2010 Feb.
Article in English, German | MEDLINE | ID: mdl-19582661

ABSTRACT

PURPOSE: Conventional sonography at 2 - 10 MHz cannot permeate the chest because ultrasound at this frequency is strongly scattered and reflected by air inclusions in the lungs. Therefore, sonography is considered impracticable for thoracic imaging. However, human thoraxes and lungs in situ were never rigorously probed with ultrasound at frequencies below 1 MHz. In addition, ultrasound is commonly applied as echo imaging rather than sound transmission. MATERIALS AND METHODS: Human subjects were studied with a transducer detector pair or an elastic thorax belt equipped with 12 sensors 5 cm apart that was wrapped around the thorax and a single pulse transmitter attached to the sternum. We focused on fast ultrasound transmission from 1 kHz to 1 MHz, coupled over thoracic sonotrodes. RESULTS: Between 1 Hz to 1 MHz, sound transmission through thorax and lungs shows three distinct bands: < 1 kHz sound is transmitted at 30 - 50 m/sec, between 1 - 10 kHz sound transmission is absent and > 10 kHz sound is transmitted with a speed of 1500 m/sec. We demonstrate that low-frequency ultrasound (10 - 750 kHz) can permeate the thorax and permits monitoring of the air and water content of human lungs. In healthy subjects at 15 kHz, the difference in sound transmission through thorax and lungs between inspiration and expiration was dynamic and spanned several decades. Sound transmission during expiration was strongly decreased in patients suffering from pulmonary emphysema or pneumothorax, but increased in patients with pleural effusions. CONCLUSION: Sound transmission in the lungs is characterized by three distinct frequency bands. Low frequency ultrasound is transmitted through the lungs and may offer a novel non-invasive approach to real time diagnostics.


Subject(s)
Extravascular Lung Water/diagnostic imaging , Image Processing, Computer-Assisted/instrumentation , Lung Diseases/diagnostic imaging , Lung/diagnostic imaging , Monitoring, Physiologic/instrumentation , Pulmonary Emphysema/diagnostic imaging , Transducers , Ultrasonography/instrumentation , Adult , Aged , Aged, 80 and over , Exhalation/physiology , Female , Humans , Inhalation/physiology , Lung Volume Measurements , Male , Middle Aged , Pleural Effusion/diagnostic imaging , Pneumothorax/diagnostic imaging , Pulmonary Disease, Chronic Obstructive/diagnostic imaging , Pulmonary Fibrosis/diagnostic imaging , Reference Values , Sarcoidosis, Pulmonary/diagnostic imaging , Sensitivity and Specificity , Sound Spectrography/instrumentation
19.
Internist (Berl) ; 50(7): 779-80, 782-4, 786-7, 2009 Jul.
Article in German | MEDLINE | ID: mdl-19436978

ABSTRACT

The pathophysiology of sepsis is not completely understood. Bacteria are the main cause of sepsis. Activated receptors of the innate immune system lead to an exaggerated immune response. Immune cells including activated neutrophils and macrophages express and are controlled by a variety of cytokines, chemokines, complement factors and other mediators. These proinflammatory factors induce the expression of secondary mediators such as lipids and reactive oxygen species leading to further amplification of inflammation. Due to loss of control mechanisms in sepsis the immune response causes damage of the own organism. The early phase of sepsis is characterized by a proinflammatory response. In contrast, in the late stage of sepsis an anti-inflammatory milieu is observed that can cause severe immunosuppression. An overview will be given on the recent advances in understanding the interaction of different pathophysiological mechanisms and potential therapeutic interventions in the complex and dynamic syndrome of sepsis.


Subject(s)
Cytokines/immunology , Immunologic Factors/immunology , Models, Immunological , Sepsis/immunology , Sepsis/therapy , Animals , Humans , Sepsis/microbiology
20.
Rev Sci Instrum ; 79(11): 113903, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19045899

ABSTRACT

Time-resolved surface photovoltage (SPV) is an important method for studying charge separation, for example, in nanostructured semiconductors. High precision differential measurement of SPV transients was realized with two identical measurement capacitors and high-impedance buffers. In addition, logarithmic readout and averaging procedures were implemented for single transients over eight magnitudes in time. As a model system ultrathin CdS layers were investigated. The thickness dependencies of the SPV amplitudes and that of the dominating relaxation mechanisms are demonstrated and discussed.


Subject(s)
Cadmium Compounds/chemistry , Electricity , Sulfides/chemistry , Electric Capacitance , Electric Impedance , Electrodes , Equipment Design , Fluorides/chemistry , Glass/chemistry , Lasers , Semiconductors , Sensitivity and Specificity , Surface Properties , Time Factors , Tin Compounds/chemistry
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