Doping-Induced Enhancement of Hydrogen Evolution at MoS2 Electrodes.

Rate theory and DFT calculations of hydrogen evolution reaction (HER) on MoS2 with Co, Ni and Pt impurities show the significance of dihydrogen (H2*) complex where both hydrogen atoms are interacting with the surface. Stabilization of such a complex affects the competing Volmer-Heyrovsky (direct H2 release) and Volmer-Tafel (H2* intermediate) pathways. The resulting evolution proceeds with a very small overpotential for all dopants ( η ${\eta }$ =0.1 to 0.2 V) at 25 % edge substitution, significantly reduced from the already low η ${\eta }$ =0.27 V for the undoped edge. At full edge substitution, Co-MoS2 remains highly active ( η ${\eta }$ =0.18 V) while Ni- and Pt-MoS2 are deactivated ( η ${\eta }$ =0.4 to 0.5 V) due to unfavorable interaction with H2*. Instead of the single S-vacancy, the site of intrinsic activity in the basal plane was found to be the undercoordinated central Mo-atom in threefold S-vacancy configurations, enabling hydrogen evolution with η ${\eta }$ =0.52 V via a H2* intermediate. The impurity atoms interact favorably with the intrinsic sulfur vacancies on the basal plane, stabilizing but simultaneously deactivating the triple vacancy configuration. The calculated shifts in overpotential are consistent with reported measurements, and the dependence on doping level may explain variations in experimental observations.

Is the doped MoS2 basal plane an efficient hydrogen evolution catalyst? Calculations of voltage-dependent activation energy.

Transition metal dichalcogenides are cheap and earth-abundant candidates for the replacement of precious metals as catalyst materials. Experimental measurements of the hydrogen evolution reaction (HER), for example, have demonstrated significant electrocatalytic activity of MoS2 but there is large variation depending on the preparation method. In order to gain information about the mechanism and active sites for the HER, we have carried out calculations of the reaction and activation energy for HER at the transition metal doped basal plane of MoS2 under electrochemical conditions, i.e. including applied electrode potential and solvent effects. The calculations are based on identifying the relevant saddle points on the energy surface obtained from density functional theory within the generalized gradient approximation, and the information on energetics is used to construct voltage-dependent volcano plots. Doping with 3d-metal atoms as well as Pt is found to enhance hydrogen adsorption onto the basal plane by introducing electronic states within the band gap, and in some cases (Co, Ni, Cu, Pt) significant local symmetry breaking. The Volmer-Heyrovsky mechanism is found to be most likely and the associated energetics show considerable dopant and voltage-dependence. While the binding free energy of hydrogen can be tuned to be seemingly favorable for HER, the calculated activation energy turns out to be significant, at least 0.7 eV at a voltage of -0.5 V vs. SHE, indicating low catalytic activity of the doped basal plane. This suggests that other sites are responsible for the experimental activity, possibly edges or basal plane defects.

Sulfur-deficient edges as active sites for hydrogen evolution on MoS2.

A grand-canonical approach is employed to calculate the voltage-dependent activation energy and estimate the kinetics of the hydrogen evolution reaction (HER) on intrinsic sites of MoS2, including edges of varying S-coverage as well as S-vacancies on the basal plane. Certain edge configurations are found to be vastly more active than others, namely S-deficient edges on the Mo-termination where, in the fully S-depleted case, HER can proceed with activation energy below 0.5 eV at an electrode potential of 0 V vs. SHE. There is a clear distinction between the performance of Mo-rich and S-rich adsorption sites, as HER at the latter sites is characterized by large (generally above 1.5 eV) Heyrovsky and Tafel energy barriers despite near-thermoneutral hydrogen adsorption energy. Thus, exposing Mo-atoms on the edges to which hydrogen can directly bind is crucial for efficient hydrogen evolution. While S-vacancies on the basal plane do expose Mo-rich sites, the energy barriers are still significant due to high coordination of the Mo atoms. Kinetic modelling based on the voltage-dependent reaction energetics gives a theoretical overpotential of 0.25 V and 1.09 V for the Mo-edge with no S atoms and the weakly sulfur-deficient (2% S-vacancies) basal plane, respectively, with Volmer-Heyrovsky being the dominant pathway. These values coincide well with reported experimentally measured values of the overpotential for the edges and basal plane. For the partly Mo-exposed edges, the calculated overpotential is 0.6-0.7 V while edges with only S-sites give overpotential exceeding that of the basal plane. These results show that the overpotential systematically decreases with increased sulfur-deficiency and reduced Mo-coordination. The fundamental difference between Mo- and S-rich sites suggests that catalyst design of transition metal dichalcogenides should be focused on facilitating and modifying the metal sites, rather than activating the chalcogen sites.

[Castleman's disease in the rheumatological practice]. / Morbus Castleman in der rheumatologischen Praxis.

The term Castleman's disease encompasses a group of rare lymphoproliferative diseases that show histopathological similarities in lymph node biopsy. Diagnostic criteria and a specific ICD-10 code have been available for a few years. Case studies listed at the beginning illustrate that close cooperation between clinicians and pathologists is required to enable a reliable diagnosis. For an optimal histopathological assessment, the pathologist is also dependent on the removal of a complete lymph node. Before distinguishing a potentially fatal multicentric idiopathic Castleman's disease from the resectable unicentric form, which is important in terms of prognosis and treatment, early diagnosis presupposes that Castleman's disease is considered in the differential diagnosis. Various immune phenomena and overlaps with autoimmune diseases can increase the probability of misdiagnosis or undetected cases in the clinical routine of rheumatologists. The intention of the present overview is therefore to point out the similarities with autoimmune diseases that are relevant for differential diagnoses and to point out situations that justify a review of the previous diagnosis.

The xylem of anisohydric Quercus alba L. is more vulnerable to embolism than isohydric codominants.

The coordination of plant leaf water potential (ΨL ) regulation and xylem vulnerability to embolism is fundamental for understanding the tradeoffs between carbon uptake and risk of hydraulic damage. There is a general consensus that trees with vulnerable xylem more conservatively regulate ΨL than plants with resistant xylem. We evaluated if this paradigm applied to three important eastern US temperate tree species, Quercus alba L., Acer saccharum Marsh. and Liriodendron tulipifera L., by synthesizing 1600 ΨL observations, 122 xylem embolism curves and xylem anatomical measurements across 10 forests spanning pronounced hydroclimatological gradients and ages. We found that, unexpectedly, the species with the most vulnerable xylem (Q. alba) regulated ΨL less strictly than the other species. This relationship was found across all sites, such that coordination among traits was largely unaffected by climate and stand age. Quercus species are perceived to be among the most drought tolerant temperate US forest species; however, our results suggest their relatively loose ΨL regulation in response to hydrologic stress occurs with a substantial hydraulic cost that may expose them to novel risks in a more drought-prone future.

[Nailfold capillaroscopy-Principles and clinical application]. / Kapillarmikroskopie ­ Grundlagen und klinische Anwendung.

Nailfold capillaroscopy is a rapid and easily applicable differential diagnostic technique that allows direct visualization of the microcirculation. Abnormal findings in nailfold capillaroscopy are closely associated with connective tissue diseases, such as systemic sclerosis. The clinical manifestation of impaired microcirculation is Raynaud's phenomenon, which is a classical symptom of connective tissue diseases. Nailfold capillaroscopy is increasingly used in various fields of medicine, therefore it is important to define methods for the acquisition and analysis of the results of nailfold capillary and to have a uniform definition of abnormal capillaries. This article discusses image acquisition and analysis, various capillaroscopic techniques, normal and abnormal capillaroscopic features and their significance, scoring systems and reliability of image acquisition and interpretation.

[Further development of regional early care-Many roads lead to Rome : Developmental stages of four established rheumatological early care concepts in different regions of Germany]. / Regionale Frühversorgung weiterentwickeln ­ Viele Wege führen nach Rom : Entwicklungsetappen von 4 etablierten rheumatologischen Frühversorgungskonzepten in verschiedenen Regionen Deutschlands.

In order to shorten the prognostically relevant waiting time until diagnosis and initiation of appropriate treatment in inflammatory rheumatic diseases, rheumatological centers in many regions across Germany have established and continuously developed specific early care concepts. Evaluated models from Altötting·Burghausen, Berlin Buch, Düsseldorf and Heidelberg and their developmental stages as a response to internal and external challenges are presented in this overview. The transparent publication of the developmental steps and the exchange of experiences aim at promoting new early care concepts in other regions and continuing the joint dialogue for improvement of the early detection and quality of care of inflammatory rheumatic diseases in Germany.

[Determinants of health-related quality of life in systemic lupus erythematosus: a monocentric, retrospective long-term observational study in Germany]. / Determinanten gesundheitsbezogener Lebensqualität bei systemischem Lupus erythematodes: eine monozentrische, retrospektive Langzeitobservationsstudie in Deutschland.

BACKGROUND: Improvement of health-related quality of life (HRQoL) is a prioritized treatment target in systemic lupus erythematosus (SLE). A retrospective chart review of patients with repeated HRQoL measurements from the outpatient department was conducted in order to better understand which factors drive HRQoL in established SLE. Of particular interest was the association between HRQoL and disease activity. METHODS: The medical outcomes study short form 36 (SF-36), systemic lupus activity measure (SLAM) and routine clinical data of 169 patients (83% female, mean age 40.3 ± 13 years, disease duration 9.4 ± 7 years) over an average of 7.1 ± 4.2 years were available for analysis by linear mixed modelling. Factors associated with the physical component summary (PCS) and mental component summary (MCS) of the SF-36 were assessed. The proportion of HRQoL which could be explained by the variables was estimated by marginal R2 (mR2) and conditional R2 (cR2). RESULTS: At baseline, SLE patients showed a reduced HRQoL in all subscales of the SF-36 including PCS and MCS with the exception of vitality. A higher PCS over time was significantly associated with concurrent parameters, such as intake of antimalarial drugs, no glucocorticoid use, less fatigue, lower disease activity as well as to the baseline parameters of younger age and higher PCS (mR2 54.7%, cR2 59.9%). A higher MCS was associated with concurrent use of glucocorticoids and a higher baseline MCS (mR2 21.7%, cR2 25.1%). CONCLUSION: The use of antimalarial drugs and no glucocorticoid intake as well as low current disease activity are modifiable factors associated with a better physical HRQoL. The mental component of HRQoL was poorly represented by conventional parameters and not associated with parameters of disease activity in the present study cohort.

[Early recognition and screening consultation: a necessary way to improve early detection and treatment in rheumatology? : Overview of the early recognition and screening consultation models for rheumatic and musculoskeletal diseases in Germany]. / Früh- und Screeningsprechstunden: Ein notwendiger Weg zur besseren Frühversorgung in der internistischen Rheumatologie? : Rheumatologische Früh- und Screeningsprechstundenmodelle in Deutschland.

In order to reduce the prognostically relevant time interval between the initial manifestation of a rheumatic and musculoskeletal disease and diagnosis as well as the consecutive initiation of an appropriate treatment, several rheumatological centers in Germany have improved the access to initial rheumatologic evaluation by establishing early recognition/screening clinics at their respective sites. Corresponding models located at Altoetting·Burghausen, Bad Pyrmont, Berlin Buch, Duesseldorf, Heidelberg, Herne, Mannheim as well as supraregional/multicenter initiatives Rheuma Rapid, RhePort and Rheuma-VOR are presented in this overview along with the respective characteristics, potential advantages and disadvantages, but also first evaluation results of several models. The aim of this publication is to promote early detection of rheumatic and musculoskeletal diseases as one of the most important challenges in current rheumatology by encouraging further rheumatologic centers and practices to launch their own early recognition/screening consultation model on the basis of aspects presented herein.

Age-specific prevalence of diagnosed systemic lupus erythematosus in Germany 2002 and projection to 2030.

OBJECTIVE: The objective of this report is to estimate the prevalence and future number of cases of systemic lupus erythematosus (SLE) in Germany. METHODS: Data from a representative sample of all insurants from the statutory health insurance in Germany comprising more than 2.3 million individuals have been screened for SLE diagnoses. The gender- and age-specific prevalence of SLE is calculated. The case definition is based on at least one recorded diagnosis of SLE during 2002. The stratum-specific prevalence is applied to the current and the future population of Germany in order to estimate and predict the number of people with SLE until 2030. RESULTS: The overall prevalence of diagnosed SLE in 2002 was 15.4 (95% CI: 13.1-17.9) and 55.4 (51.4, 59.8) per 100,000 in the male and female German population. This corresponds to an estimated 30,000 and 31,000 people with diagnosed SLE in 2002 and 2010, respectively. This number will slightly increase until 2020 and decrease thereafter. CONCLUSIONS: Compared with health insurance data from France, the prevalence in our data is similar. Under the assumption that the gender- and age-specific prevalence of SLE in Germany will not change considerably, the number of cases in the next two decades will change only slightly.

Autoinflammatory diseases (AID).

Most of the autoinflammatory diseases (AID) are orphan diseases with recurrent episodes of systemic inflammation. Fever and exanthema are leading features. Given the ongoing elucidation of pathogenic causes and hence therapeutic approaches, we provided a review of the current literature of AID.

[Gender-specific differences in capillaroscopy in healthy persons and patients with inflammatory rheumatic diseases]. / Geschlechtsspezifische Unterschiede bei Gesunden und Patienten mit entzündlich-rheumatischen Erkrankungen in der Kapillarmikroskopie.

BACKGROUND: Capillaroscopy is an established tool to assess morphological and functional findings of the microcirculation which have a confirmed association with disease activity and damage of inflammatory rheumatic diseases, especially systemic sclerosis. Hairpin-shaped capillaries with normal density predict a very low risk for collagenosis. METHODS: Own databases were evaluated with respect to the topic of the manuscript and the current literature was evaluated. RESULTS: The healthy population does not only demonstrate hairpin shape as capillaroscopic normal findings and morphological and functional abnormalities can also be found which show various patterns depending on gender and age. These can be found in healthy persons and also patients with collagenosis. Ectasia and sludge phenomenon are more common in women and tortuous capillaries are more common in men. Capillary filling is often decreased in women and increased in male patients. CONCLUSION: When assessing capillaroscopy findings, gender and the morphological or functional alterations which can be found in the normal healthy population should be taken into consideration. In further studies with capillaroscopy as the target parameter, the potential source of the disturbance should be known, especially in small populations, and if necessary balanced by weighted randomization.

Patient-reported outcomes in large vessel vasculitis: insights from a retrospective analysis of disease activity and associated factors.

BACKGROUND: Patient-reported outcomes (PROs) play a crucial role in assessing rheumatic diseases, offering insights into disease evaluation and treatment efficacy. This study focuses on PRO assessment in large vessel vasculitides, including Takayasu Arteritis and Giant Cell Arteritis (GCA). METHODS: We retrospectively analyzed routine data from patients treated at our rheumatology clinic over a 10-year span. Patient and physician-rated global disease activity scale (G-DAS) scores, measured on a numeric rating scale (0-10 points), were collected at each visit. Clinical variables like age, sex, body mass index (BMI), disease duration, lab values, pain perception, and questionnaire responses were recorded. Linear regression and generalized additive linear regression (GAM analysis) examined associations between PROs and these factors. RESULTS: The study included 138 patients, primarily diagnosed with GCA (94.4%). Mean follow-up was 2.5 years (0-7.7). Patient and physician G-DAS exhibited a moderate correlation (Pearson R 0.19, CI 0.14-0.24, p < 0.001). Higher patient G-DAS correlated with younger age (CI -3.4 - -1.5, p < 0.001), increased pain (CI 3.5-4, p < 0.001), functional limitations (HAQ, CI 0.5-0.6, p < 0.001), reduced physical (CI 2.3-2.7, p ≤ 0.001) and psychological well-being (CI 2.1-2.5, p < 0.001), and higher BMI (CI 1.3-2.4, p < 0.001). Physician G-DAS correlated with Birmingham Vasculitis Activity Score (V3.0; R 0.42, p 0.046) and were significantly linked to serum CRP elevations (ß = 0.04, CI 0.0-0.08, p 0.028). CONCLUSIONS: These findings underscore the need to integrate PRO measures into vasculitis disease management strategies, enhancing the understanding of disease activity from the patient's perspective.

Validation and evaluation of the German Brief Index of Lupus Damage (BILD)--a self-reported instrument to record damage in systemic lupus erythematosus.

INTRODUCTION: Damage is a very important predictor for outcome in systemic lupus erythematosus (SLE) and should be routinely documented. Patient-reported assessments for damage are rare and neither the Lupus Damage Index Questionnaire (LDIQ) nor the Brief Index of Lupus Damage (BILD) is validated in German language. Our aim was to validate the BILD in German language and evaluate its use as a patient-administered instrument. METHOD: We translated and adapted the BILD questionnaire to use it as a self-administered questionnaire for German-speaking SLE patients. It was applied to SLE outpatients at an academic centre and compared to the SLICC/SDI and other lupus outcome parameters. RESULTS: The German BILD showed as strong a correlation with the SLICC/SDI as the original version of the BILD and a superior correlation compared to the LDIQ. It scored significantly higher with an increase of age, disease duration or disease activity, with a lower functional status or overall health and a higher probability of receiving an incapacity pension. CONCLUSION: The German version of the BILD shows a comparable validity to the original BILD with even higher correlation to physician-reported damage even when used as a self-administered questionnaire. Hence it represents a promising instrument to survey damage in clinical routine as well as in clinical and epidemiological studies.

An unusual presentation of a common infection.

A 40-year-old Ghanaian woman presented with fever and exanthema. She had anemia, leukopenia, increased erythrocyte sedimentation rate (ESR), creatinin kinase, lactate dehydrogenase (LDH), and liver enzymes. She was diagnosed with schistosomiasis and was cured with praziquantel. During the following years, she developed polymyositis, chronic nephritis, and life-threatening perimyocarditis. High numbers of Epstein-Barr virus (EBV)-encoded RNA copies were demonstrated in CD8+ T-lymphocytes from endomyocardial biopsies. There was no evidence of any underlying immunosuppression or an EBV-related malignancy. Chronic active EBV infection was diagnosed, a clinical picture not described in an adult African previously. Interestingly, among all therapy attempts, only rituximab was effective at stabilizing the disease.

[Capillaroscopy. An update]. / Kapillarmikroskopie. Ein Update.

This article reports relevant innovations 2 years after the publication of the German consensus on nomenclature and procedure of capillaroscopy in this journal. Standardization: certified training courses in capillaroscopy under the patronage of the Rheumatism Academy have reached over 300 rheumatologists nationwide. Trained investigators clearly show greater agreement on findings than untrained experts even with years of experience. Normal findings were detected using the published terminology in a large cohort. Scientific application: the number of publications on capillaroscopy has risen significantly, prospective studies of smaller cohorts and the comparison to other methods regarding systemic sclerosis, Raynaud's disease and also miscellaneous diseases. A large prospective multicenter European study on the capillaroscopic skin ulcer risk index (CSURI) was conducted with German participation. The role as a screening tool has been confirmed by the majority of the studies. For systemic lupus erythematosus it is also increasingly being used in the diagnostic work-up as an additional investigation. Practical application: capillaroscopy has a solid and indispensable role in the diagnostic algorithm of Raynaud's disease and early diagnosis of systemic sclerosis. Videocapillaroscopy and simple USB microscopes are increasingly being used besides traditional light microscopy.

[Nailfold capillaroscopy-Principles and clinical application]. / Kapillarmikroskopie ­ Grundlagen und klinische Anwendung.

Nailfold capillaroscopy is a rapid and easily applicable differential diagnostic technique that allows direct visualization of the microcirculation. Abnormal findings in nailfold capillaroscopy are closely associated with connective tissue diseases, such as systemic sclerosis. The clinical manifestation of impaired microcirculation is Raynaud's phenomenon, which is a classical symptom of connective tissue diseases. Nailfold capillaroscopy is increasingly used in various fields of medicine, therefore it is important to define methods for the acquisition and analysis of the results of nailfold capillary and to have a uniform definition of abnormal capillaries. This article discusses image acquisition and analysis, various capillaroscopic techniques, normal and abnormal capillaroscopic features and their significance, scoring systems and reliability of image acquisition and interpretation.