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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 313: 124148, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38492463

RESUMO

Oleogel represents a promising healthier alternative to act as a substitute for conventional fat in various food products. Oil selection is a crucial factor in determining the technological properties and applications of oleogels due to their distinct fatty acid composition, molecular weight, and thermal properties, as well as the presence of antioxidants and oxidative stability. Hence, the relevance of monitoring oleogel properties by non-destructive, eco-friendly, portable, fast, and effective techniques is a relevant task and constitutes an advance in the evaluation of oleogels quality. Thus, the present study aims to classify oleogels rapidly and reliably, without the use of chemicals, comparing two handheld near infrared (NIR) spectrometers and one portable Raman device. Furthermore, two different multivariate methods are compared for oleogel classification according to oil type. Three types of oleogels were prepared, containing 95 % oil (sunflower, soy, olive) and 5 % beeswax as a structuring agent, melted at 90 °C. Polarized light microscopy (PLM) images were acquired, and fatty acid composition, peroxide index and free fatty acid content were determined using official methods. A total of 240 oleogel and 92 oil spectra were obtained for each instrument. After spectra pretreatment, Principal Component Analysis (PCA) was performed, and two classification methods were investigated. The Data Driven - Soft Independent Modelling of Class Analogy (DD-SIMCA) and Partial Least Squares Discriminant Analysis (PLS-DA) models demonstrated 95 % to 100 % of accuracy for the external test set. In conclusion, the use of vibrational spectroscopy using handheld and portable instruments in tandem with chemometrics showed to be an efficient alternative for classifying oils and oleogels and could be extended to other food samples. Although the classification of vegetable oils by NIR is widely used and known, this work proposes the classification of different types of oil in oleogel matrices, which has not yet been explored in the literature.


Assuntos
Quimiometria , Óleos de Plantas , Ácidos Graxos/química , Análise Espectral , Compostos Orgânicos
2.
Molecules ; 28(23)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38067622

RESUMO

The following investigations describe the potential of handheld NIR spectroscopy and Raman imaging measurements for the identification and authentication of food products. On the one hand, during the last decade, handheld NIR spectroscopy has made the greatest progress among vibrational spectroscopic methods in terms of miniaturization and price/performance ratio, and on the other hand, the Raman spectroscopic imaging method can achieve the best lateral resolution when examining the heterogeneous composition of samples. The utilization of both methods is further enhanced via the combination with chemometric evaluation methods with respect to the detection, identification, and discrimination of illegal counterfeiting of food products. To demonstrate the solution to practical problems with these two spectroscopic techniques, the results of our recent investigations obtained for various industrial processes and customer-relevant product examples have been discussed in this article. Specifically, the monitoring of food extraction processes (e.g., ethanol extraction of clove and water extraction of wolfberry) and the identification of food quality (e.g., differentiation of cocoa nibs and cocoa beans) via handheld NIR spectroscopy, and the detection and quantification of adulterations in powdered dairy products via Raman imaging were outlined in some detail. Although the present work only demonstrates exemplary product and process examples, the applications provide a balanced overview of materials with different physical properties and manufacturing processes in order to be able to derive modified applications for other products or production processes.


Assuntos
Cacau , Espectroscopia de Luz Próxima ao Infravermelho , Cacau/química , Alimentos , Controle de Qualidade , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Análise Espectral Raman/métodos
3.
Anal Chem ; 95(17): 6888-6893, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37070825

RESUMO

For successful soil remediation and hydrocarbon exploration operations, determining the total petroleum hydrocarbon (TPH) content of soils is an indispensable process step. This paper reports on the performance of a handheld Fourier transform near-infrared (FT-NIR) spectrometer for rapid and quantitative determination of TPH content of soils from two different sites by diffuse reflection measurements. For rapid decisions for exploration work or environmental site assessment projects, a quick─preferably on-site─determination of TPH content is valuable. Diffuse reflection NIR spectra were recorded from soil samples of two different sites with TPH reference values ranging from 350 to 30,000 ppm, as determined by capillary gas chromatography and flame ionization detection with hydrocarbon fingerprinting C1-C44. However, this paper not only addresses the development of site-specific partial-least squares (PLS) calibrations but also demonstrates the locally-weighted PLS (LW-PLS) technique, which can be used to develop global, site-independent PLS calibrations without significant penalty in calibration performance. As a first step, the diffuse reflection spectra were used to develop conservative, site-specific PLS calibration models with root-mean-square calibration/cross-validation errors (RMSEC/RMSECV) of 1043/1106 and 741/785 ppm TPH, respectively, and the average absolute prediction errors for samples not contained in the calibration set were 451 and 293 ppm for the two sites, respectively. In a further step, significant degradation of the RMSE values of a conservative PLS model based on the NIR spectra of both sites was then compared to the application of the LW-PLS method, with only a slight loss of the prediction accuracy relative to the site-independent models. This study confirms the ability of next-generation portable FT-NIR spectrometers to predict low TPH levels in various soil types through both─soil-specific and site-independent─calibrations, giving these spectrometers the potential to become rapid screening tools in the field.

4.
J Antimicrob Chemother ; 76(3): 635-638, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33374010

RESUMO

BACKGROUND: The performance of the galactomannan enzyme immunoassay (GM-EIA) is impaired in patients receiving mould-active antifungal therapy. The impact of mould-active antifungal therapy on Aspergillus PCR testing needs to be determined. OBJECTIVES: To determine the influence of anti-mould prophylaxis (AMP) on the performance of PCR blood testing to aid the diagnosis of proven/probable invasive aspergillosis (IA). METHODS: As part of the systematic review and meta-analysis of 22 cohort studies investigating Aspergillus PCR blood testing in 2912 patients at risk of IA, subgroup analysis was performed to determine the impact of AMP on the accuracy of Aspergillus PCR. The incidence of IA was calculated in patients receiving and not receiving AMP. The impact of two different positivity thresholds (requiring either a single PCR positive test result or ≥2 consecutive PCR positive test results) on accuracy was evaluated. Meta-analytical pooling of sensitivity and specificity was performed by logistic mixed-model regression. RESULTS: In total, 1661 (57%) patients received prophylaxis. The incidence of IA was 14.2%, significantly lower in the prophylaxis group (11%-12%) compared with the non-prophylaxis group (18%-19%) (P < 0.001). The use of AMP did not affect sensitivity, but significantly decreased specificity [single PCR positive result threshold: 26% reduction (P = 0.005); ≥2 consecutive PCR positive results threshold: 12% reduction (P = 0.019)]. CONCLUSIONS: Contrary to its influence on GM-EIA, AMP significantly decreases Aspergillus PCR specificity, without affecting sensitivity, possibly as a consequence of AMP limiting the clinical progression of IA and/or leading to false-negative GM-EIA results, preventing the classification of probable IA using the EORTC/MSGERC definitions.


Assuntos
Aspergilose , Infecções Fúngicas Invasivas , Aspergilose/diagnóstico , Aspergilose/prevenção & controle , Aspergillus/genética , Humanos , Mananas , Metanálise como Assunto , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade
5.
Anaesthesist ; 70(2): 146-154, 2021 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-33185697

RESUMO

Providing medical care to patients suffering from the coronavirus disease 2019 (COVID-19) pandemic is a major challenge for government healthcare systems around the world. The new coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), shows a high organ specificity for the lower respiratory tract. Since there is so far no effective treatment or vaccination against the virus, early diagnostic recognition is of great importance. Due to the specific aspects of the infection, which mainly begins in the peripheral lung parenchyma, lung ultrasonography is suitable as a diagnostic imaging method to identify suspected cases as such in the early stages of the disease. Serial ultrasound examinations on patients with confirmed COVID-19 can promptly detect changes in the affected lung tissue at the bedside. This article summarizes the diagnostic potential of lung ultrasound with respect to screening and therapeutic decision-making in patients with suspected or confirmed SARS-CoV­2 pneumonia.


Assuntos
COVID-19/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Ultrassonografia/métodos , COVID-19/diagnóstico , Teste para COVID-19 , Humanos , Pandemias
6.
Chimia (Aarau) ; 74(12): 921, 2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33357283
7.
Front Plant Sci ; 10: 1548, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827484

RESUMO

Recently, miniaturization of Raman, mid-infrared (MIR) and near-infrared (NIR) spectrometers have made substantial progress, and marketing companies predict this segment of instrumentation a significant growth rate within the next few years. This increase will be based on a more frequent implementation for industrial quality and process control and a broader adoption of spectrometers for in-the-field testing, on-site measurements, and every-day-life consumer applications. The reduction in size, however, must not lead to compromises in measurement performance and the hand-held instrumentation will only have a real impact if spectra of comparable quality to laboratory spectrometers can be obtained. The present communication will, on the one hand, explain the instrumental reasons why NIR spectroscopy is presently the most advanced technique regarding miniaturization and on the other hand, it will emphasize the impact of NIR spectroscopy for plant analysis by discussing in some detail a qualitative and a quantitative application example.

8.
Molecules ; 24(19)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581527

RESUMO

The band shapes and band positions of near-infrared (NIR) and Raman spectra change depending on the concentrations of specific chemical functionalities in a multicomponent system. To elucidate these effects in more detail and clarify their impact on the analytical measurement techniques and evaluation procedures, NIR transmission spectra and Raman spectra of two organic liquid three-component systems with variable compositions were analyzed by two different multivariate calibration procedures, partial least squares (PLS) and classical least-squares (CLS) regression. Furthermore, the effect of applying different concentration units (volume percent (%V) and weight percent (%W) on the performance of the two calibration procedures have been tested. While the mixtures of benzene/cyclohexane/ethylbenzene (system 1) can be regarded as a blended system with comparatively low molecular interactions, hydrogen bonding plays a dominant role in the blends of ethyl acetate/1-heptanol/1,4-dioxane (system 2). Whereas system 1 yielded equally good calibrations by PLS and CLS regression, for system 2 acceptable results were only obtained by PLS regression. Additionally, for both sample systems, Raman spectra generally led to lower calibration performance than NIR spectra. Finally, volume and weight percent concentration units yielded comparable results for both chemometric evaluation procedures.


Assuntos
Hidrocarbonetos Cíclicos/isolamento & purificação , Derivados de Benzeno/isolamento & purificação , Calibragem , Cicloexanos/isolamento & purificação , Ligação de Hidrogênio , Análise dos Mínimos Quadrados , Peso Molecular , Espectroscopia de Luz Próxima ao Infravermelho , Análise Espectral Raman
9.
Molecules ; 24(11)2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31141878

RESUMO

Nowadays, near infrared (NIR) spectroscopy has experienced a rapid progress in miniaturization (instruments < 100 g are presently available), and the price for handheld systems has reached the < $500 level for high lot sizes. Thus, the stage is set for NIR spectroscopy to become the technique of choice for food and beverage testing, not only in industry but also as a consumer application. However, contrary to the (in our opinion) exaggerated claims of some direct-to-consumer companies regarding the performance of their "food scanners" with "cloud evaluation of big data", the present publication will demonstrate realistic analytical data derived from the development of partial least squares (PLS) calibration models for six different nutritional parameters (energy, protein, fat, carbohydrates, sugar, and fiber) based on the NIR spectra of a broad range of different pasta/sauce blends recorded with a handheld instrument. The prediction performance of the PLS calibration models for the individual parameters was double-checked by cross-validation (CV) and test-set validation. The results obtained suggest that in the near future consumers will be able to predict the nutritional parameters of their meals by using handheld NIR spectroscopy under every-day life conditions.


Assuntos
Alimentos , Avaliação Nutricional , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Calibragem , Análise dos Mínimos Quadrados
10.
J Hosp Infect ; 101(3): 339-346, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30423409

RESUMO

BACKGROUND: Invasive mucormycosis (IM) is a rare invasive fungal infection with a high mortality rate. However, data concerning the clinical and economic burden of IM are scarce. AIM: To evaluate the direct treatment costs and additional expenditures of patients with IM. METHODS: A retrospective cost-of-illness analysis of cases with IM extracted from FungiScope - Global Registry for Emerging Fungal Infections, accessible through the epidemiological research platform www.ClinicalSurveys.net, was undertaken. Results of patients with IM were compared with those of matched patients with similar underlying conditions based on the German Diagnosis Related Group (G-DRG) coding. FINDINGS: Out of 46 patients with probable/proven IM, 31 (67%) patients were male and the median age was 53 years (range 11-88 years). Forty-two patients (92%) had haematological diseases as the most common risk factor. Analysis of cost factors identified antifungal treatment due to IM as the primary cost driver [€22,816, 95% confidence interval (CI) €15,036-32,346], with mean overall direct treatment costs of €53,261 (95% CI €39,660-68,825). Compared with matched patients, patients with IM were treated in hospital for 26.5 additional days (standard deviation 31.8 days; P < 0.001), resulting in mean additional costs of €32,991 (95% CI €21,558-46,613; P < 0.001). Probable IM, as well as absence of chemotherapy, surgical measures due to IM, and antifungal prophylaxis were associated with lower overall costs. Nineteen patients (41.3%) died during hospitalization. CONCLUSION: This study demonstrates the considerable healthcare burden of IM. The choice of antifungal agent for treatment of IM had no impact on overall cost.


Assuntos
Efeitos Psicossociais da Doença , Infecções Fúngicas Invasivas/economia , Infecções Fúngicas Invasivas/epidemiologia , Mucormicose/economia , Mucormicose/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antifúngicos/economia , Antifúngicos/uso terapêutico , Criança , Feminino , Hospitalização/economia , Humanos , Infecções Fúngicas Invasivas/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Mucormicose/tratamento farmacológico , Estudos Retrospectivos , Centros de Atenção Terciária , Adulto Jovem
11.
Light Sci Appl ; 7: 101, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30534370

RESUMO

The development of wideband lasing media has deep implications for imaging, sensing, and display technologies. We show that a single chromophore can be engineered to feature wide-gamut fluorescence and lasing throughout the entire visible spectrum and beyond. This exceptional color tuning demonstrates a chemically controlled paradigm for light emission applications with precise color management. Achieving such extensive color control requires a molecular blueprint that yields a high quantum efficiency and a high solubility in a wide variety of liquids and solids while featuring a heterocyclic structure with good steric access to the lone pair electrons. With these requirements in mind, we designed a lasing chromophore that encloses a lasing color space twice as large as the sRGB benchmark. This record degree of color tuning can in principle be adapted to the solid state by incorporating the chromophore into polymer films. By appropriately engineering the base molecular structure, the widest range of lasing wavelengths observed for a conventional gain medium can be achieved, in turn establishing a possible route toward high-efficiency light emitters and lasers with near-perfect chromaticity.

12.
Nanoscale ; 10(48): 23018-23026, 2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30506071

RESUMO

Metal-organic composites are of great interest for a wide range of applications. The control of their structure remains a challenge, one of the problems being a complex interplay of covalent and supramolecular interactions. This paper describes the self-assembly, thermal stability and phase transitions of ordered structures of silver atoms and thiol molecules spanning from the molecular to the mesoscopic scale. Building blocks of molecularly defined clusters formed from 44 silver atoms, each particle coated by a monolayer of 30 thiol ligands, are used as ideal building blocks. By changing solvent and temperature it is possible to tune the self-assembled 3D crystals of pristine nanoparticles or, conversely, 2D layered structures, with alternated stacks of Ag atoms and thiol monolayers. The study investigates morphological, chemical and structural stability of these materials between 25 and 300 °C in situ and ex situ at the nanoscale by combining optical and electronic spectroscopic and scattering techniques, scanning probe microscopies and density-functional theory (DFT) calculations. The proposed wet-chemistry approach is relatively cheap, easy to implement, and scalable, allowing the fabricated materials with tuned properties using the same building blocks.

13.
J Pharm Biomed Anal ; 160: 179-186, 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30096648

RESUMO

Notwithstanding the first developments of miniaturized vibrational spectrometers more than a decade ago, only recently real handheld near-infrared (NIR) spectrometers (<200 g) became commercially available at significantly reduced costs compared to other portable systems. While on the one hand this development was driven by the consumer request for every-day-life applications by non-experts, on the manufacturer side it was supported by the availability and potential of new technologies such as micro-electromechanical systems (MEMS). In the present communication calibration spectra of a solid pharmaceutical formulation consisting of two excipients and three active ingredients, acetylsalicylic acid (ASA), ascorbic acid (ASC) and caffeine (CAF), have been measured with four handheld NIR spectrometers based on different monochromator principles and have subsequently been used to develop partial least squares (PLS) models for the quantitative determination of the active ingredients. Taking into account the instrumental and spectral peculiarities of the four instruments and the three analytes, respectively, the detailed analysis of the calibration parameters and the prediction accuracy for a test sample set then allowed to compare the performance of the different spectrometers for the analytical problem under investigation.


Assuntos
Composição de Medicamentos/estatística & dados numéricos , Estudos de Avaliação como Assunto , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Ácido Ascórbico/análise , Aspirina/análise , Cafeína/análise , Calibragem , Espectroscopia de Luz Próxima ao Infravermelho/métodos
14.
Appl Spectrosc ; 72(9): 1362-1370, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29855195

RESUMO

For sustainable utilization of raw materials and environmental protection, the recycling of the most common polymers-polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polystyrene (PS)-is an extremely important issue. In the present communication, the discrimination performance of the above polymer commodities based on their near-infrared (NIR) spectra measured with four real handheld (<200 g) spectrometers based on different monochromator principles were investigated. From a total of 43 polymer samples, the diffuse reflection spectra were measured with the handheld instruments. After the original spectra were pretreated by second derivative and standard normal variate (SNV), principal component analysis (PCA) was applied and unknown samples were tested by soft independent modeling of class analogies (SIMCA). The results show that the five polymer commodities cluster in the score plots of their first three principal components (PCs) and, furthermore, samples in calibration and test sets can be correctly identified by SICMA. Thus, it was concluded that on the basis of the NIR spectra measured with the handheld spectrometers the SIMCA analysis provides a suitable analytical tool for the correct assignment of the type of polymer. Because the mean distance between clusters in the score plot reflects the discrimination capability for each polymer pair the variation of this parameter for the spectra measured with the different handheld spectrometers was used to rank the identification performance of the five polymer commodities.


Assuntos
Polímeros , Espectroscopia de Luz Próxima ao Infravermelho , Calibragem , Polímeros/análise , Polímeros/química , Polímeros/classificação , Análise de Componente Principal , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Espectroscopia de Luz Próxima ao Infravermelho/normas
15.
Ann Oncol ; 29(6): 1354-1365, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29688266

RESUMO

Infectious complications are a significant cause of morbidity and mortality in patients with malignancies specifically when receiving anticancer treatments. Prevention of infection through vaccines is an important aspect of clinical care of cancer patients. Immunocompromising effects of the underlying disease as well as of antineoplastic therapies need to be considered when devising vaccination strategies. This guideline provides clinical recommendations on vaccine use in cancer patients including autologous stem cell transplant recipients, while allogeneic stem cell transplantation is subject of a separate guideline. The document was prepared by the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO) by reviewing currently available data and applying evidence-based medicine criteria.


Assuntos
Anti-Infecciosos/uso terapêutico , Doenças Transmissíveis/tratamento farmacológico , Neoplasias Hematológicas/terapia , Neoplasias/terapia , Guias de Prática Clínica como Assunto/normas , Transplante de Células-Tronco/efeitos adversos , Vacinação/normas , Doenças Transmissíveis/etiologia , Humanos , Prognóstico
16.
Clin Microbiol Infect ; 24 Suppl 1: e1-e38, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29544767

RESUMO

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.


Assuntos
Antifúngicos/uso terapêutico , Aspergilose/diagnóstico , Aspergilose/tratamento farmacológico , Aspergillus/isolamento & purificação , Gerenciamento Clínico , Anticorpos Antifúngicos/sangue , Antifúngicos/farmacologia , Aspergilose/complicações , Aspergilose/imunologia , Aspergillus/efeitos dos fármacos , Aspergillus/imunologia , Biópsia/métodos , Lavagem Broncoalveolar , Diagnóstico Precoce , Flucitosina/farmacologia , Flucitosina/uso terapêutico , Galactose/análogos & derivados , Humanos , Hospedeiro Imunocomprometido , Testes Imunológicos , Aspergilose Pulmonar Invasiva/diagnóstico , Itraconazol/farmacologia , Itraconazol/uso terapêutico , Leucemia Mieloide Aguda/complicações , Leucemia Mieloide Aguda/terapia , Imageamento por Ressonância Magnética , Mananas/análise , Testes de Sensibilidade Microbiana , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/terapia , Nitrilas/farmacologia , Nitrilas/uso terapêutico , Piridinas/farmacologia , Piridinas/uso terapêutico , Tomografia Computadorizada por Raios X , Triazóis/farmacologia , Triazóis/uso terapêutico , Voriconazol/farmacologia , Voriconazol/uso terapêutico
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 188: 478-482, 2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-28759848

RESUMO

In the present communication the potential of 2DCOS analysis and the spin-off technique perturbation-correlation moving window 2D (PCMW2D) analysis is illustrated with reference to spectroscopic changes observed in a data set recorded by in-line fiber-coupled FT-IR spectroscopy in the attenuated total reflection (ATR) mode during a polyurethane solution polymerization at different temperatures. In view of the chemical functionalities involved, hydrogen bonding plays an important role in this polymerization reaction. Based on the 2DCOS and PCMW2D analysis, the sequence of hydrogen bonding changes accompanying the progress of polymerization and precipitation of solid polymer can be determined. Complementary to the kinetic data derived from the original variable-temperature spectra in a previous publication the results provide a more detailed picture of the investigated solution polymerization.

18.
Neuroscience ; 371: 371-383, 2018 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-29262299

RESUMO

The molecular basis for onset, maintenance and propagation of excitation along neuronal networks in epilepsy is still poorly understood. Besides different neurotransmitter receptors that control signal transfer at the synapse, one key regulator involved in all of these processes is the ATPase N-ethylmaleimide-sensitive fusion protein (NSF). Therefore, we analyzed receptor subunits and NSF levels in tissues from the medial temporal gyrus (MTG) of patients with pharmaco-resistant focal temporal lobe epilepsy resected during epilepsy surgery and autopsy controls. The resected tissues were further characterized by field potential recordings into tissues with and without spontaneous sharp wave activity. We detected increased levels of NSF, NMDA 1.1, 2A and GABAAγ2 receptor subunits associated with spontaneous sharp wave spiking activity. We further identified correlations between NSF, AMPA receptor subunit, metabotropic glutamate receptor and adenosine 1 receptor levels in the spontaneous sharp wave spiking tissues. Our findings suggest that NSF plays a key role in controlling spontaneous network excitation in epilepsy by two mechanisms of action: (1) directly via controlling transmitter release at the presynaptic side, and (2) indirectly via altering the function of possible receptor crosstalk and directing/integrating specific receptor compounds through/into the postsynaptic membrane.


Assuntos
Epilepsia do Lobo Temporal/metabolismo , Proteínas Sensíveis a N-Etilmaleimida/metabolismo , Lobo Temporal/metabolismo , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Epilepsia Resistente a Medicamentos/metabolismo , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia do Lobo Temporal/patologia , Epilepsia do Lobo Temporal/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Receptores de Neurotransmissores/metabolismo , Lobo Temporal/patologia , Técnicas de Cultura de Tecidos
19.
Ann Hematol ; 96(11): 1775-1792, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28856437

RESUMO

Fever may be the only clinical symptom at the onset of infection in neutropenic cancer patients undergoing myelosuppressive chemotherapy. A prompt and evidence-based diagnostic and therapeutic approach is mandatory. A systematic search of current literature was conducted, including only full papers and excluding allogeneic hematopoietic stem cell transplant recipients. Recommendations for diagnosis and therapy were developed by an expert panel and approved after plenary discussion by the AGIHO. Randomized clinical trials were mainly available for therapeutic decisions, and new diagnostic procedures have been introduced into clinical practice in the past decade. Stratification into a high-risk versus low-risk patient population is recommended. In high-risk patients, initial empirical antimicrobial therapy should be active against pathogens most commonly involved in microbiologically documented and most threatening infections, including Pseudomonas aeruginosa, but excluding coagulase-negative staphylococci. In patients whose expected duration of neutropenia is more than 7 days and who do not respond to first-line antibacterial treatment, specifically in the absence of mold-active antifungal prophylaxis, further therapy should be directed also against fungi, in particular Aspergillus species. With regard to antimicrobial stewardship, treatment duration after defervescence in persistently neutropenic patients must be critically reconsidered and the choice of anti-infective agents adjusted to local epidemiology. This guideline updates recommendations for diagnosis and empirical therapy of fever of unknown origin in adult neutropenic cancer patients in light of the challenges of antimicrobial stewardship.


Assuntos
Doenças Transmissíveis/diagnóstico , Febre de Causa Desconhecida/diagnóstico , Hematologia/normas , Oncologia/normas , Neutropenia/diagnóstico , Guias de Prática Clínica como Assunto/normas , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/terapia , Febre de Causa Desconhecida/epidemiologia , Febre de Causa Desconhecida/terapia , Alemanha/epidemiologia , Hematologia/métodos , Humanos , Oncologia/métodos , Neutropenia/epidemiologia , Neutropenia/terapia , Sociedades Médicas/normas
20.
Anal Bioanal Chem ; 409(3): 833-839, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27376357

RESUMO

Polyurethanes are a polymer class with large property diversity. However, despite their extreme technical importance, only few research data regarding the on-line analysis and the derivation of kinetic polymerization data are available in the literature. The present work focuses on the in-line monitoring of the solution polymerization of 4,4'-diphenylmethanediisocyanate and 1,4-butanediol by fiber-coupled FT-IR spectroscopy in the attenuated total reflection (ATR) mode at variable temperatures and the interpretation of the spectral changes as a function of polymerization progress. Furthermore, the activation energy of the solution polymerization will be derived from the kinetic data and experimental issues of the ATR in-line measurement mode will be addressed.

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