Pleiotropic Effects of PhaR Regulator in Bradyrhizobium diazoefficiens Microaerobic Metabolism.

Bradyrhizobium diazoefficiens can live inside soybean root nodules and in free-living conditions. In both states, when oxygen levels decrease, cells adjust their protein pools by gene transcription modulation. PhaR is a transcription factor involved in polyhydroxyalkanoate (PHA) metabolism but also plays a role in the microaerobic network of this bacterium. To deeply uncover the function of PhaR, we applied a multipronged approach, including the expression profile of a phaR mutant at the transcriptional and protein levels under microaerobic conditions, and the identification of direct targets and of proteins associated with PHA granules. Our results confirmed a pleiotropic function of PhaR, affecting several phenotypes, in addition to PHA cycle control. These include growth deficiency, regulation of carbon and nitrogen allocation, and bacterial motility. Interestingly, PhaR may also modulate the microoxic-responsive regulatory network by activating the expression of fixK2 and repressing nifA, both encoding two transcription factors relevant for microaerobic regulation. At the molecular level, two PhaR-binding motifs were predicted and direct control mediated by PhaR determined by protein-interaction assays revealed seven new direct targets for PhaR. Finally, among the proteins associated with PHA granules, we found PhaR, phasins, and other proteins, confirming a dual function of PhaR in microoxia.

Impact of daily physical therapy over 2 weeks on spinal mobility including objective electronic measurements and function in patients with axial spondyloarthritis.

Background: Patients with axial spondyloarthritis (axSpA) are often compromised by impaired function and mobility. The standardized 2-week inpatient program 'multimodal rheumatologic complex treatment' (MRCT) was designed for patients with axSpA. The Epionics SPINE (ES) is an objective tool validated to assess mobility. Objective: To investigate the impact of MRCT on physical function and mobility including range of motion (RoM) and kinematics (RoK). Design: Single-center interventional, observational trial. Methods: Patients with axSpA presenting with high disease activity and impaired physical function were consecutively recruited to undergo MRCT. Assessments performed before (V1) and after (V2) the intervention included Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis functional index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), the ankylosing spondylitis physical performance index (ASPI), the Short Physical Performance Battery (SPPB), and ES measurements. Results: At baseline, the 80 patients included had: BASDAI 5.5 ± 1.5, BASFI 5.6 ± 2.0, BASMI 4.2 ± 1.8, SPPB 13.8 ± 1.8, and ASPI 37.3 ± 18.1 s. Clinically relevant improvements between V1 versus V2 were noted for BASFI, BASMI, and all other assessments (p < 0.001), and also for ES measures of RoK (all p < 0.003) and RoM (all p < 0.04), while a positive trend was seen for flexion and extension (RoM). There was no significant effect of changes in medication (all p > 0.05). Conclusion: The 2-weeks MRCT was associated with definite improvements of function and mobility. Importantly, the effect of this extensive physical activity was confirmed by using the ES as an objective tool to assess spinal mobility. The ES demonstrated for the first time that the RoK of spinal mobility can significantly improve related to an exercise intervention. Trial registration: Ethical Committee: Ruhr-Universität (reference-number: 19-6735-BR).

Clinically relevant differences in spinal mobility related to daytime performance in patients with axial spondyloarthritis.

OBJECTIVE: Patients with axial spondyloarthritis (axSpA) suffer from clinical symptoms like morning stiffness and back pain. Mobility of patients with axSpA is often impaired. The aim of this study is to compare the performance of patients with axSpA regarding mobility measures including performance-based tests and objective electronic assessments with the Epionics SPINE device (ES) at different times of the day compared with healthy controls (HC). METHODS: Observational trial, consecutive inpatients with axSpA (n=100) and 20 HCs were examined in the morning (V1: before 10:00 am) and in the afternoon (V2: after 02:00 pm) by the Bath Ankylosing Spondylitis Metrology Index (BASMI), the AS physical performance index (ASPI), the Short Physical Performance Battery (SPPB) and ES measurements, including range of motion (RoM) and range of kinematics (RoK). RESULTS: The assessments of patients with axSpA performed in the morning clearly differed from those in the afternoon, especially regarding performance-based tests. Significant improvements were seen for BASMI (4.0±3.8 to 3.8±1.9; p<0.001), ASPI (36.2±18.3 to 28.8±11.9 s; p<0.001), SPPB (10.1±1.5 to 10.7±1.4 points; p<0.001) and for ES measures of speed (RoK; p<0.018) but not for RoM, except for lateral flexion (13.3±7.4 to 14.7±8.2°; p=0.002). This time of assessment-related variability was not observed in HC. CONCLUSION: The spinal mobility of patients with axSpA was worse in the morning but significantly improved in the afternoon. This was captured best by performance-based measures and was not seen in HC. The diurnal variation of mobility has implications for clinical studies, suggesting that the time of assessments needs to be standardised.

Analysis of the carbide precipitation and microstructural evolution in HCCI as a function of the heating rate and destabilization temperature.

Microstructural modification of high chromium cast irons (HCCI) through the precipitation of secondary carbides (SC) during destabilization treatments is essential for improving their tribological response. However, there is not a clear consensus about the first stages of the SC precipitation and how both the heating rate (HR) and destabilization temperature can affect the nucleation and growth of SC. The present work shows the microstructural evolution, with a special focus on the SC precipitation, in a HCCI (26 wt% Cr) during heating up to 800, 900, and 980 °C. It was seen that the HR is the most dominant factor influencing the SC precipitation as well as the matrix transformation in the studied experimental conditions. Finally, this work reports for first time in a systematic manner, the precipitation of SC during heating of the HCCI, providing a further understanding on the early stages of the SC precipitation and the associated microstructural modifications.

Patients' awareness towards physical activity in the treatment of axial spondyloarthritis.

INTRODUCTION: The course of axial spondyloarthritis (axSpA) is often characterized by impairments in physical function and mobility. Regular physical activity (PA) is a cornerstone of axSpA management. Recent European League Against Rheumatism (EULAR) recommendations for PA have stressed the importance of their implementation. OBJECTIVE: Cohort study to investigate the awareness on and individual implementation of axSpA patients towards PA. METHODS: Patients with axSpA and impaired physical function (Bath AS Functional Index [BASFI] score≥2.0) were recruited consecutively. All patients underwent a clinical examination including assessments of disease activity, physical function, mobility and global functioning. Patients also had to fill out structured questionnaires on knowledge, awareness and individual attitudes to PA. RESULTS: Out of a total of 100 patients enrolled, 96 were included. Most respondents (n=82, 85.4%) were aware that PA has significant health benefits for patients with axSpA. Even though less than half of the patients (n=44, 42.7%) were aware that actual EULAR recommendations do exist, 45 patients (46.9%) did already fulfill these in terms of frequency/week. The majority of patients (n=61, 67.7%) had been informed about the benefits of PA by their physician, and physiotherapy had often been prescribed (n=61, 63.3%). Many patients (n=51, 53.1%) reported to perform individual exercise programs, and some (n=22, 22.9) supervised PA. CONCLUSION: Even though the majority of axSpA patients are not aware of the recent EULAR recommendations for PA, many understand and agree that PA is beneficial for their health status. Health care providers should concentrate on the patients who are not active and do not know about the benefits of PA.

Correlative Site-Specific Sample Preparation for Atom Probe Tomography on Complex Microstructures.

Site-specific specimen preparation for atom probe tomography (APT) is a challenging task. Small features need to be located using a suitable imaging technique and captured within a volume of less than 0.01 µm3. Correlative microscopy has shown to be helpful for target preparation as well as to gain complementary information about the material. Current strategies developed in that direction can be highly time-consuming and not always ensure the correct site extraction in complex microstructures. In this work, we present a methodology to study grain boundaries and interfaces in martensitic steels by combining electron backscattered diffraction, transmission Kikuchi diffraction (TKD), and APT. Furthermore, we include the design of a sample holder that allows to perform TKD and scanning transmission electron microscopy on the specimen during preparation without breaking the vacuum of the scanning electron microscope/focused ion beam workstation. We show a case study where a prior austenite grain boundary is traced from the bulk material to the apex of the APT specimen. The presence of contamination due to the specimen exposure to the electron beam and the use of plasma cleaning to minimize it are discussed.