Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Bioorg Med Chem Lett ; 96: 129501, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37804995

RESUMO

The enzyme aldosterone synthase (CYP11B2) is specifically expressed in aldosterone-producing tissue of the adrenal cortex and is overexpressed in aldosterone-producing adenomas (APA). It therefore represents an ideal target for molecular imaging, particularly for the differential diagnosis between bilateral hyperplasia and unilateral APA in primary aldosteronism. However, the presence of the cortisol-producing enzyme 11ß-hydroxylase (CYP11B1) in the adrenal cortex remains very challenging owing to its high homology to CYP11B2. Within this study, we efficiently synthesized a variety of disubstituted fluorinated pyridines and pyrazines by Suzuki coupling reactions. These compounds were evaluated for their ability to inhibit CYP11B1 and CYP11B2 in transfected Y1 cells and in NCI-h295 cells. Several compounds were found to exhibit excellent affinity (IC50 < 10 nM) to CYP11B2 as well as strong selectivity (up to 125-fold) over CYP11B1. These findings support the further development of an analogous 18F-labelled PET tracer.


Assuntos
Adenoma , Hiperaldosteronismo , Humanos , Citocromo P-450 CYP11B2 , Esteroide 11-beta-Hidroxilase , Aldosterona , Hiperaldosteronismo/diagnóstico , Diagnóstico Diferencial
2.
Artigo em Alemão | MEDLINE | ID: mdl-36589472

RESUMO

Objective: Preliminary results from activity surveys conducted in spring 2020 suggest that athletic activity may have decreased within the contact restrictions against the spread of coronavirus. The coronavirus pandemic poses many challenges to the workforce in the healthcare system. Therefore, this study investigated whether the measures to limit the pandemic have an influence on the activity behavior of employees in the public sector. Method: A retrospective cross-sectional survey was conducted to collate the activity behavior among employees of three institutions in the public sector before and during the measures against the coronavirus in April 2020. An online version of the Freiburg Activity Questionnaire was used. Using Wilcoxon tests on connected samples with a significance level of p < 0.05, the activity behavior was examined for differences before compared to during the contact restrictions in min/week and MET-min./week. Results: A total of 1797 public sector employees in Freiburg (36.0% male, 63.9% female, and 0.1% diverse) participated in the survey. For sports activity, a relevant difference (p < 0.05) was measured in the medians (Mdn) of activities per week before (Mdn = 180 min) and during (Mdn = 120 min) the relevant contact restrictions. Similarly, for energy expenditure through exercise, the median value within the contact restrictions decreased from Mdn = 1022 MET-min/week to Mdn = 750 MET-min./week. Conclusion: Measures to limit the spread of the coronavirus have led to a reduction in activity levels among public sector employees. In particular, fewer employees engaged in sports. This could be related to the closure of fitness studios as these activities were particularly reduced. Decreased physical activity can lead to unfavorable individual risk profiles, which must be compensated for in the future.

3.
Phys Chem Chem Phys ; 24(48): 29371-29380, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36448738

RESUMO

Organic molecular thin-films are employed for manufacturing a wide variety of electronic devices, including memory devices and transistors. A precise description of the atomic-scale interactions in aromatic carbon systems is of paramount importance for the design of organic thin-films and carbon-based nanomaterials. Here we investigate the binding and structure of pyrazine on graphite with neutron diffraction and spin-echo measurements. Diffraction data of the ordered phase of deuterated pyrazine, (C4D4N2), adsorbed on the graphite (0001) basal plane surface are compared to scattering simulations and complemented by van der Waals corrected density functional theory calculations. The lattice constant of pyrazine on graphite is found to be (6.06 ± 0.02) Å. Compared to benzene (C6D6) adsorption on graphite, the pyrazine overlayer appears to be much more thermodynamically stable, up to 320 K, and continues in layer-by-layer growth. Both findings suggest a direct correlation between the intensity of van der Waals bonding and the stability of the self-assembled overlayer because the nitrogen atoms in the six-membered ring of pyrazine increase the van der Waals bonding in comparison to benzene, which only contains carbon atoms.

4.
Herpetologica ; 74(2): 127-134, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30078848

RESUMO

In the majority of anuran species, acoustic signals are the dominant mode of inter- and intrasexual communication. Male calls are always accompanied by the movement of a more or less conspicuous vocal sac-a potential visual cue. Reed frogs possess a striking vocal sac with a colorful patch of gland tissue clearly visible once the vocal sac is inflated during acoustic signaling. To investigate the visual signal function of vocal sac and gular gland, we presented male Spotted Reed Frogs (Hyperolius puncticulatus) with unimodal and multimodal signal playbacks of conspecific rivals in their natural habitat and recorded their behavioral responses. We found no difference in receiver response to unimodal advertisement call stimuli and to multimodal stimulus presentations of calls combined with visual signals of an artificial vocal sac with or without a gular patch, moving synchronously or asynchronously with the call playback. The inflations of a vocal sac with a colorful gular patch did not alter receiver response and neither increase nor decrease signal salience during male-male communication. Interestingly, males frequently displayed a novel hind and front foot-tapping behavior in response to all playbacks. Comparison of male responses to advertisement and aggressive call playbacks showed that Spotted Reed Frogs approached the sound source less during aggressive call presentations. Tapping behavior was not influenced by either call playback. We suggest that the gestural tapping behavior might act as vibrational signal and discuss its potential signal function in male contests and courtship for females.

5.
Chemistry ; 23(5): 1018-1022, 2017 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-27689679

RESUMO

Hexasubstituted C3 -symmetric benzenes with three elongated shape-persistent oligo(phenylenevinylene) arms and three pyridyl hydrogen-bond acceptors have been synthesized. These mesogens assemble in a double-helical columnar liquid crystal (LC) structure, owing to the compensation of free spaces between conjugated arms by dimer formation. The void is filled also by up to three anthracene carboxylic acids as guests forming hydrogen bonded supermesogens assembling in columnar LC and soft-crystal phases. Thin film fluorescence and solid-state NMR spectroscopy imply a transition from a disordered columnar LC to an unexpected double nanosegregated morphology of a filled soft columnar crystal phase. An additional intracolumnar separation of anthracene and oligo(phenylenevinylene) chromophores occurs, separate to the general segregation of aliphatic and aromatic building blocks in LC structures. The new type of supermesogens will enable the rational design of host-guest double cables with a wide range of different conjugated building blocks.

6.
Chemistry ; 23(5): 1060-1068, 2017 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-27761945

RESUMO

The molecular design of crowded hexasubstituted star mesogens based on a benzene core and alternating substitution with oligo(phenylenevinylene) arms and aryl units generates free space between the conjugated arm scaffolds. Various arylcarboxy building blocks, decorated with alkoxy chains, have been incorporated in the void by mixing, hydrogen bonding or covalent bonds to the aryl groups. The mesogens assemble in columnar stacks ranging from soft crystals to rectangular and hexagonal columnar liquid crystals, revealed by polarized optical microscopy, differential scanning calorimetry, X-ray scattering and modelling. The stability of the mesophases is crucially influenced by the binding mode of the arylcarboxy guest building blocks. The origin of the variation in clearing temperature is unravelled by modelling, cohesive energy density considerations and solid-state NMR spectroscopy. The control over the transition temperature is important for the formation of aligned thin films and thus for potential applications.

7.
Euro Surveill ; 22(14)2017 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-28422005

RESUMO

Between 1 June and 31 December 2016, 13,023 blood donations from the University Hospital Aachen in Germany were routinely screened for West Nile virus (WNV) RNA using the cobas TaqScreen WNV Test. On 28 September 2016, one blood donor was tested positive. Subsequent analysis revealed an acute Usutu virus (USUV) infection. During the ongoing USUV epizootics in Germany, blood transfusion services, public health authorities and clinicians should be aware of increased human USUV infections.


Assuntos
Infecções por Flavivirus/diagnóstico , Febre do Nilo Ocidental/diagnóstico , Adulto , Anticorpos Antivirais/imunologia , Doadores de Sangue , Vírus da Encefalite Japonesa (Espécie)/imunologia , Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Feminino , Flavivirus/genética , Flavivirus/imunologia , Infecções por Flavivirus/imunologia , Alemanha/epidemiologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Programas de Rastreamento , RNA Viral/sangue , RNA Viral/genética , Febre do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/genética , Vírus do Nilo Ocidental/imunologia
8.
Angew Chem Int Ed Engl ; 54(33): 9710-4, 2015 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-26101202

RESUMO

Hexasubstituted C3 -symmetric benzenes with three oligophenylenevinylene (OPV) arms and three pyridyl or phenyl substituents are shape-persistent star mesogens that are sterically crowded in the center. Such molecular structures possess large void spaces between their arms, which have to be filled in condensed phases. For the neat materials, this is accomplished by an exceptional formation of dimers and short-range helical packing in columnar mesophases. The mesophase is thermodynamically stable for the pyridyl compound. Only this derivative forms filled star-shaped supermesogens in the presence of various carboxylic acids. The latter do not arrange as dimers, but as monomers along the columnar stacks. In this liquid crystal (LC) phase, the guests are completely enclosed by the hosts. Therefore, the host can be regarded as a new LC endoreceptor, which allows the design of columnar functional structures in the future.

9.
Curr Cancer Drug Targets ; 23(5): 412-424, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36281866

RESUMO

BACKGROUND: Treatment with immune checkpoint inhibitors has improved both progressionfree survival and overall survival in a subset of patients with tumors. However, the selection of patients who benefit from immune checkpoint inhibitor treatment remains challenging. Positron Emission Tomography (PET) is a non-invasive molecular imaging tool that offers a promising alternative to the current IHC for detecting the PD-L1 expression in malignant cells in vivo, enabling patient selection and predicting the response to individual patient immunotherapy treatment. OBJECTIVES: Herein, we report the development of novel [18F]labeled pyridine-2-carboxamide derivatives [18F]2 and [18F]3 as small-molecule probes for imaging immune checkpoint (PD-1/PD-L1) in cancer using PET. METHODS AND RESULTS: [18F]2 and [18F]3 were prepared by a one-step radiofluorination in 44 ± 5% and 30 ± 4% radiochemical yield and > 98% radiochemical purity for a potential clinical translation. The total synthesis time, including HPLC purification, was less than 45 min. [18F]2 and [18F]3 showed excellent stability in injection solution and a significant accumulation and retention in PD-1/PD-L1 expressing MDA-MB-231 breast cancer and in HeLa cervix carcinoma cells (2- 5 cpm/1000 cells). In addition, autoradiographic analysis and inhibition experiments on tumor slices confirm the potential of both compounds as specific imaging probes for the PD-1/PD-L1 axis in tumors. CONCLUSION: The in vitro evaluation in PD-L1 expressing cells together with results from autoradiographic analysis in PD-L1 positive tumor sections, suggest that [18F]2 and [18F]3 could be potential imaging probes for assessing PD-L1 expression in tumors and warrant further biological evaluations in vivo.


Assuntos
Antígeno B7-H1 , Neoplasias , Feminino , Humanos , Antígeno B7-H1/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Compostos Radiofarmacêuticos , Piridinas
10.
J Occup Environ Med ; 65(9): e587-e592, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37311075

RESUMO

OBJECTIVES: This article compares the impact of COVID-19-related restrictions on the level of physical activity, performed by public servants, in April and November 2020. METHODS: The survey examined the amount (in minutes per week) and the energy expenditure (in metabolic equivalent of task in minutes per week [METmin/week]) of physical activity for both before and during contact restrictions in April and November 2020, respectively. RESULTS: Especially for sports activity difference was determined by the medians before (April/November: median [Mdn] = 180.0 min/wk) and during (April: Mdn = 130 minutes, November: Mdn = 60 min/wk) restrictions ( P < 0.05).Also for energy consumption (METmin/wk), the medians before and during the contact restrictions declined for both periods. CONCLUSIONS: Measures against the coronavirus have led to a reduction in activity levels among public employees, regardless of their work environment. The decrease in participation in sport activities seemed to be even more noticeable within the second restriction period.


Assuntos
COVID-19 , Esportes , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Exercício Físico , Inquéritos e Questionários , Metabolismo Energético
11.
J Pers Med ; 13(10)2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37888089

RESUMO

BACKGROUND: The COVID-19 pandemic resulted in unprecedented restrictions on public and private life. The aim of the study was to investigate the impact of the COVID-19 pandemic on the physical and mental health of employees in the public sector, especially patient-related professions. METHODS: For the data collection in summer 2021, an online questionnaire was used. Compared to a pre-pandemic point of time, the prevalence, frequency, and intensity of musculoskeletal pain, mental well-being, health status, and quality of life were recorded. RESULTS: The questionnaire was completed by 1678 employees (f: 1045, m: 617). A total of 1504 employees (89.6%) were affected by complaints. Compared to before the pandemic, the prevalence and intensity of musculoskeletal complaints and psychological distress increased significantly. Patient-related professions (n = 204) showed significantly higher levels of stress and discomfort in several aspects (p < 0.05). CONCLUSIONS: Due to the COVID-19 pandemic, there was an increase in musculoskeletal complaints and a decrease in psychological well-being. Preventive factors related to mental health were identified as male gender, a middle- to older-age group, employees with children, and working from home. Attention should be drawn to these findings and prevention strategies should be brought into focus to strengthen the employees' health. Special focus should be drawn to patient-related professions who are particularly confronted with pandemic-associated challenges.

12.
Front Chem ; 11: 1249290, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38033467

RESUMO

We present a detailed helium atom scattering study of the charge-density wave (CDW) system and transition metal dichalcogenide 1T-TaS2. In terms of energy dissipation, we determine the electron-phonon (e-ph) coupling, a quantity that is at the heart of conventional superconductivity and may even "drive" phase transitions such as CDWs. The e-ph coupling of TaS2 in the commensurate CDW phase (λ = 0.59 ± 0.12) is compared with measurements of the topo-logical insulator TlBiTe2 (λ = 0.09 ± 0.01). Furthermore, by means of elastic He diffraction and resonance/interference effects in He scattering, the thermal expansion of the surface lattice, the surface step height, and the three-dimensional atom-surface interaction potential are determined including the electronic corrugation of 1T-TaS2. The linear thermal expansion coefficient is similar to that of other transition-metal dichalcogenides. The He-TaS2 interaction is best described by a corrugated Morse potential with a relatively large well depth and supports a large number of bound states, comparable to the surface of Bi2Se3, and the surface electronic corrugation of 1T-TaS2 is similar to the ones found for semimetal surfaces.

13.
Front Public Health ; 11: 1223748, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38035288

RESUMO

Introduction: During the first months of the COVID pandemic it emerged that facilities where people gather or live together in cohorts, such as nursing homes or schools, were particularly at high risk for becoming hotspots of virus transmission. German political and health institutions responded with far-reaching interventions and preventive strategies to protect the population from infection with SARS-CoV-2. In this context, it remains unclear whether boarding schools for sports particularly pose a risk of infection to their residents. Methods: In a single-center prospective cohort study, numbers of SARS-CoV-2 infections of students in sports boarding schools (n = 11) vs. students attending regular day schools (n = 22) in the region Freiburg/Hochschwarzwald in Germany were investigated over a period from October 2020 to January 2021 via regular virus and antibody screening (German Clinical Trials Register; Study ID: DRKS00021909). In addition, individual and behavioral risk factors for infection were stratified via questionnaire, which provide an indication of cohort specific risk factors for infection and the success of the implementation of hygiene concepts, as well as other infection prevention strategies, within the respective facilities. Results: Regarding SARS-CoV-2 infection numbers, the screening detected no significant group difference between sports boarding schools vs. day schools. Discussion: The study results provide indications that sports boarding schools did not pose an increased risk of infection, assuming that the facilities prevent virus transmissions with appropriate preventive strategies and hygiene measures. In future pandemic scenarios larger-scale and multicenter studies are necessary to achieve more comprehensive epidemiological data in this field.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2 , Pandemias/prevenção & controle , Estudos Prospectivos , Instituições Acadêmicas , Estudantes
14.
Orthopadie (Heidelb) ; 52(10): 834-842, 2023 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-37567919

RESUMO

INTRODUCTION: MPFL reconstruction represents one of the most important surgical treatment options for recurrent patellar dislocations at low flexion angles associated with low flexion patellofemoral instability. Nevertheless, the role of quadriceps muscles in patients with patellofemoral instability before and after patellofemoral stabilization using MPFL reconstruction has not been fully elucidated. The present study investigates the influence of quadriceps muscles on the patellofemoral contact in patients with low flexion patellofemoral instability (PFI) before and after surgical patellofemoral stabilization using MPFL reconstruction using 3 T MRI datasets in early degrees of flexion (0-30°). METHODS: In this prospective cohort study, 15 patients with low flexion PFI before and after MPFL reconstruction and 15 subjects with healthy knee joints were studied using dynamic MRI scans. MRI scans were performed in a custom-made pneumatic knee loading device to determine the patellofemoral cartilage contact area (CCA) with and without quadriceps activation (50 N). Comparative measurements were performed using 3D cartilage and bone meshes in 0-30° knee flexion in the patients with patellofemoral instability preoperatively and postoperatively. RESULTS: The preoperative patellofemoral CCA of patients with low flexion PFI was 67.3 ± 47.3 mm2 in 0° flexion, 118.9 ± 56.6 mm2 in 15° flexion, and 267.6 ± 96.1 mm2 in 30° flexion. With activated quadriceps muscles (50 N), the contact area was 72.4 ± 45.9 mm2 in extension, 112.5 ± 54.9 mm2 in 15° flexion, and 286.1 ± 92.7 mm2 in 30° flexion without statistical significance. Postoperatively determined CCA revealed 159.3 ± 51.4 mm2 , 189.6 ± 62.2 mm2 and 347.3 ± 52.1 mm2 in 0°, 15° and 30° flexion. Quadriceps activation with 50 N showed a contact area in extension of 141.0 ± 63.8 mm2, 206.6 ± 67.7 mm2 in 15° flexion, and 353.5 ± 64.6 mm2 in 30° flexion, also without statistical difference compared with unloaded CCAs. Subjects with healthy knee joints showed an increase of 10.3% in CCA at 30° of flexion (p = 0.003). CONCLUSION: Although patellofemoral CCA increases significantly after isolated MPFL reconstruction in patients with low flexion patellofemoral instability, there is no significant influence of quadriceps muscles either preoperatively or postoperatively.


Assuntos
Articulação Patelofemoral , Humanos , Articulação Patelofemoral/diagnóstico por imagem , Músculo Quadríceps/diagnóstico por imagem , Estudos Prospectivos , Tendões , Ligamentos Articulares/cirurgia , Fenômenos Biomecânicos
15.
Sci Data ; 10(1): 590, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37679367

RESUMO

The modelling of electricity production and demand requires highly specific and comprehensive meteorological data. One challenge is the high temporal frequency as electricity production and demand modelling typically is done with hourly data. On the other side the European electricity market is highly connected, so that a pure country-based modelling is not expedient and at least the whole European Union (EU) area has to be considered. Additionally, the spatial resolution of the data set must be able to represent the thermal conditions, which requires high spatial resolution at least in mountainous regions. All these requirements lead to huge data amounts for historic observations and even more for climate change projections for the whole 21st century. Thus, we have developed the aggregated European wide climate data set SECURES-Met that has a temporal resolution of one hour, covers the whole EU area and other selected European countries, has a reasonable size but considers the high spatial variability.

16.
J Clin Med ; 12(5)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36902705

RESUMO

BACKGROUND: Patellofemoral instability (PFI) leads to chronic knee pain, reduced performance and chondromalacia patellae with consecutive osteoarthritis. Therefore, determining the exact patellofemoral contact mechanism, as well as the factors leading to PFI, is of great importance. The present study compares in vivo patellofemoral kinematic parameters and the contact mechanism of volunteers with healthy knees and patients with low flexion patellofemoral instability (PFI). The study was performed with a high-resolution dynamic MRI. MATERIAL/METHODS: In a prospective cohort study, the patellar shift, patella rotation and the patellofemoral cartilage contact areas (CCA) of 17 patients with low flexion PFI were analyzed and compared with 17 healthy volunteers, matched via the TEA distance and sex, in unloaded and loaded conditions. MRI scans were carried out for 0°, 15° and 30° knee flexion in a custom-designed knee loading device. To suppress motion artifacts, motion correction was performed using a moiré phase tracking system with a tracking marker attached to the patella. The patellofemoral kinematic parameters and the CCA was calculated on the basis of semi-automated cartilage and bone segmentation and registrations. RESULTS: Patients with low flexion PFI showed a significant reduction in patellofemoral CCA for 0° (unloaded: p = 0.002, loaded: p = 0.004), 15° (unloaded: p = 0.014, loaded: p = 0.001) and 30° (unloaded: p = 0.008; loaded: p = 0.001) flexion compared to healthy subjects. Additionally, patients with PFI revealed a significantly increased patellar shift when compared to volunteers with healthy knees at 0° (unloaded: p = 0.033; loaded: p = 0.031), 15° (unloaded: p = 0.025; loaded: p = 0.014) and 30° flexion (unloaded: p = 0.030; loaded: p = 0.034) There were no significant differences for patella rotation between patients with PFI and the volunteers, except when, under load at 0° flexion, PFI patients showed increased patellar rotation (p = 0.005. The influence of quadriceps activation on the patellofemoral CCA is reduced in patients with low flexion PFI. CONCLUSION: Patients with PFI showed different patellofemoral kinematics at low flexion angles in both unloaded and loaded conditions compared to volunteers with healthy knees. Increased patellar shifts and decreased patellofemoral CCAs were observed in low flexion angles. The influence of the quadriceps muscle is diminished in patients with low flexion PFI. Therefore, the goal of patellofemoral stabilizing therapy should be to restore a physiologic contact mechanism and improve patellofemoral congruity for low flexion angles.

17.
Orthop J Sports Med ; 11(5): 23259671231160215, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37213660

RESUMO

Background: Medial patellofemoral ligament (MPFL) reconstruction is a well-established procedure for the treatment of patients with patellofemoral instability (PFI) at low flexion angles (0°-30°). Little is known about the effect of MPFL surgery on patellofemoral cartilage contact area (CCA) during the first 30° of knee flexion. Purpose/Hypothesis: The purpose of this study was to investigate the effect of MPFL reconstruction on CCA using magnetic resonance imaging (MRI). We hypothesized that patients with PFI would have a lower CCA than patients with healthy knees and that CCA would increase after MPFL reconstruction over the course of low knee flexion. Study Design: Cohort study; Level of evidence, 2. Methods: In a prospective matched-paired cohort study, the CCA of 13 patients with low-flexion PFI was determined before and after MPFL reconstruction, and the data were compared with those of 13 healthy volunteers (controls). MRI was performed with the knee at 0°, 15°, and 30° of flexion in a custom-designed knee-positioning device. To suppress motion artifacts, motion correction was performed using a Moiré Phase Tracking system via a tracking marker attached to the patella. The CCA was calculated on the basis of semiautomatic cartilage and bone segmentation and registration. Results: The CCA (mean ± SD) at 0°, 15°, and 30° of flexion for the control participants was 1.38 ± 0.62, 1.91 ± 0.98, and 3.68 ± 0.92 cm2, respectively. In patients with PFI, the CCA at 0°, 15°, and 30° of flexion was 0.77 ± 0.49, 1.26 ± 0.60, and 2.89 ± 0.89 cm2 preoperatively and 1.65 ± 0.55, 1.97 ± 0.68, and 3.52 ± 0.57 cm2 postoperatively. Patients with PFI exhibited a significantly reduced preoperative CCA at all 3 flexion angles when compared with controls (P ≤ .045 for all). Postoperatively, there was a significant increase in CCA at 0° of flexion (P = .001), 15° of flexion (P = .019) and 30° of flexion (P = .026). There were no significant postoperative differences in CCA between patients with PFI and controls at any flexion angle. Conclusion: Patients with low-flexion patellar instability showed a significant reduction in patellofemoral CCA at 0°, 15°, and 30° of flexion. MPFL reconstruction increased the contact area significantly at all angles.

18.
PLoS One ; 14(4): e0214219, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31002711

RESUMO

Selenium plays an important, but vastly neglected role in human nutrition with a narrow gap between dietary deficiency and toxicity. For a potential biofortification of food with Se, as well as for toxicity-risk assessment in sites contaminated by Se, modelling of local and global Se cycling is essential. As bioavailability of Se for rice plants depends on the speciation of Se and the resulting interactions with mineral surfaces as well as the interaction with Se uptake mechanisms in plants, resulting plant Se content is complex to model. Unfortunately, simple experimental models to estimate Se uptake into plants from substrates have been lacking. Therefore, a mass balance of Se transfer between lithosphere (represented by kaolinite), hydrosphere (represented by a controlled nutrient solution), and biosphere (represented by rice plants) has been established. In a controlled, closed, lab-scale system, rice plants were grown hydroponically in nutrient solution supplemented with 0-10 000 µg L-1 Se of either selenate or selenite. Furthermore, in a series of batch experiments, adsorption and desorption were studied for selenate and selenite in competition with each of the major nutrient oxy-anions, nitrate, sulfate and phosphate. In a third step, the hydroponical plants experiments were coupled with sorption experiments to study synergy effects. These data were used to develop a mass balance fitting model of Se uptake and partitioning. Adsorption was well-described by Langmuir isotherms, despite competing anions, however, a certain percentage of Se always remained bio-unavailable to the plant. Uptake of selenate or selenite by transporters into the rice plant was fitted with the non-time differentiated Michaelis-Menten equation. Subsequent sequestration of Se to the shoot was better described using a substrate-inhibited variation of the Michaelis-Menten equation. These fitted parameters were then integrated into a mass balance model of Se transfer.


Assuntos
Oryza/metabolismo , Plântula/química , Selênio/metabolismo , Disponibilidade Biológica , Transporte Biológico , Humanos , Hidroponia , Nitratos/química , Nitratos/metabolismo , Avaliação Nutricional , Oryza/química , Fosfatos/química , Raízes de Plantas/química , Raízes de Plantas/crescimento & desenvolvimento , Selênio/toxicidade
19.
ESC Heart Fail ; 5(5): 846-857, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30168657

RESUMO

AIM: The aim of this study is to analyse the prognostic value of complement anaphylatoxin receptors in patients with non-ischaemic cardiomyopathy undergoing endomyocardial biopsy. METHODS AND RESULTS: In 102 patients (72.5% male patients, median age 54 years) with non-ischaemic cardiomyopathy, myocardial expression of C3aR was assessed among other parameters. The primary study endpoint was a composite of death, heart transplantation, heart failure-related re-hospitalization, and deterioration of left ventricular ejection fraction within a mean follow-up of 11.9 months. The number of cells, which stained positive for C3aR, was significantly increased in patients with inflammatory compared with non-inflammatory cardiomyopathy (1.75 ± 0.31 cells in inflammatory cardiomyopathy vs. 0.94 ± 0.26 in non-inflammatory cardiomyopathy, P = 0.049). Subsequently, positive expression for C3aR was judged based on a semi-quantitative scoring system. Significantly, more patients with positive MHCII and CD68 expression showed an increased number of C3aR-positive cells. C3aR expression based on this score was more pronounced in patients with human herpesvirus 6 viral genome detection. Kaplan-Meier curves illustrate that the C3aR-negative group reached the primary endpoint significantly more often (mean follow-up 11.9 months, log rank 5.963, P = 0.015). Lack of C3aR expression was a strong independent predictor for the primary endpoint in Cox regression analysis [hazard ratio 0.46 (0.26-0.82, P = 0.009)]. CONCLUSIONS: C3aR-positive cells are found more often in patients with inflammatory cardiomyopathy. The relevance of C3aR-positive cells in patients with non-ischaemic cardiomyopathy should be further evaluated as potential predictors or modulators of adverse cardiac remodelling, the substrate of progressive heart failure.


Assuntos
Regulação da Expressão Gênica , Insuficiência Cardíaca/genética , Miocárdio/metabolismo , RNA/genética , Receptores de Complemento/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Ecocardiografia , Feminino , Seguimentos , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Prognóstico , Receptores de Complemento/biossíntese , Estudos Retrospectivos , Adulto Jovem
20.
Artigo em Inglês | MEDLINE | ID: mdl-30200256

RESUMO

Inland waters are of great importance for scientists as well as authorities since they are essential ecosystems and well known for their biodiversity. When monitoring their respective water quality, in situ measurements of water quality parameters are spatially limited, costly and time-consuming. In this paper, we propose a combination of hyperspectral data and machine learning methods to estimate and therefore to monitor different parameters for water quality. In contrast to commonly-applied techniques such as band ratios, this approach is data-driven and does not rely on any domain knowledge. We focus on CDOM, chlorophyll a and turbidity as well as the concentrations of the two algae types, diatoms and green algae. In order to investigate the potential of our proposal, we rely on measured data, which we sampled with three different sensors on the river Elbe in Germany from 24 June⁻12 July 2017. The measurement setup with two probe sensors and a hyperspectral sensor is described in detail. To estimate the five mentioned variables, we present an appropriate regression framework involving ten machine learning models and two preprocessing methods. This allows the regression performance of each model and variable to be evaluated. The best performing model for each variable results in a coefficient of determination R 2 in the range of 89.9% to 94.6%. That clearly reveals the potential of the machine learning approaches with hyperspectral data. In further investigations, we focus on the generalization of the regression framework to prepare its application to different types of inland waters.


Assuntos
Clorofila A/análise , Clorofila/análise , Diatomáceas/crescimento & desenvolvimento , Ecossistema , Monitoramento Ambiental/instrumentação , Substâncias Húmicas/análise , Aprendizado de Máquina , Análise Espectral , Qualidade da Água , Alemanha
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA