Vector-Borne and Zoonotic Pathogens in Raccoon Dogs (Nyctereutes procyonoides) and Raccoons (Procyon lotor) from Schleswig-Holstein, Germany.

Raccoon dogs (Nyctereutes procyonoides) and raccoons (Procyon lotor) are invasive alien species originating from East Asia and North America, respectively. They are discussed as vectors and reservoirs for various infectious diseases, including vector-borne and zoonotic pathogens, and are therefore a potential threat to human and domestic animal health, as well as to biodiversity and conservation. In the years 2021 and 2022, 110 raccoon dogs (Nyctereutes procyonoides) and 30 raccoons (Procyon lotor) were screened via qPCR for the presence of Leptospira spp., Rickettsia spp. and Borreliella spp. in the German federal state of Schleswig-Holstein as part of a health and risk assessment study. Borreliella spp. were confirmed in one raccoon dog and one raccoon, identified as Borreliella afzelii in the raccoon. Leptospira spp. were found in 21 (19.44%) raccoon dogs and 2 (6.90%) raccoons. In five raccoon dogs, Leptospira spp. were identified as Leptospira borgpetersenii, Leptospira kirschneri and Leptospira interrogans.

Malicious Mites-Sarcoptes scabiei in Raccoon Dogs (Nyctereutes procyonoides) in Schleswig-Holstein, Germany.

Sarcoptic mange was detected in five free-ranging raccoon dogs (Nyctereutes procyonoides) in the federal state of Schleswig-Holstein, Germany, during a health assessment study of invasive species, including raccoon dogs, carried out between 2021 and 2022. Four raccoon dogs showed severe lesions, including extensive alopecia with thickening and hyperpigmentation of the skin (lichenification). The fifth animal was less affected, showing only thinning of the hair coat in multiple body locations. Skin scrapings were performed and confirmed the presence of Sarcoptes scabiei. Histopathology of the skin revealed diffuse epidermal hyperplasia and hyperkeratosis, mild eosinophilic dermatitis, and varying amounts of intralesional mites. Staphylococcus pseudintermedius and Corynebacterium auriscanis were detected in the skin samples of the affected animals, indicating a secondary bacterial infection. The source of sarcoptic mange remains unclear; interspecies transmission via direct or indirect contact seems likely. Raccoon dogs are therefore a potential vector for sarcoptic mange, and their behaviour could contribute to disease spread and persistence.

Demodex carolliae in a colony of Seba's short-tailed bats (Carollia perspicillata): clinical, pathological and parasitological findings.

Seba's short-tailed bats (Carollia perspicillata) are a frugivorous species native to Central and South America. Despite their importance as a reservoir for zoonotic pathogens and their popularity in zoological collection and as research models, there are relatively few reports on non-zoonotic diseases of bats. Mites of the genus Demodex are obligate commensals of the skin of a range of mammals, are highly host-specific and are not associated with clinical disease when present in low numbers. However, infestation with high numbers can result in severe or even fatal disease and substantially affect the well-being of the animals. The clinical, pathological and parasitological findings in 12 Seba's short-tailed bats with demodicosis from a colony kept at Munich Zoo Hellabrunn between 1992 and 2021 are described in this report. From 2002, skin lesions became apparent on the head, especially the periocular region, nose and ears, as well as the genital area of some animals. In advanced cases, skin changes were also present on the abdomen, back and extremities. Gross findings typically included alopecia and thickening of the skin, with the formation of papules, reflecting cystically dilated hair follicles containing myriads of demodecid mites. Histologically, lesions were characterized by a paucicellular lymphocytic dermatitis and folliculitis with perifollicular fibrosis, epidermal hyperplasia, orthokeratotic hyperkeratosis and disproportionately high numbers of intrafollicular arthropods. Demodex carolliae was identified morphologically by light, phase-contrast and electron microscopy. Further characterization was achieved by extraction of parasitic DNA and partial gene sequencing of two mitochondrial genes, 16S rDNA and cox1. This is the first clinicopathological description of generalized demodicosis in Seba's short-tailed bats and includes the first molecular characterization of D. carolliae with provision of a GenBank entry.

The Outcome of Psychiatric Rehabilitation Treatment Depends on Affective State at the Time of Admission.

BACKGROUND: In Austria, new approaches of rehabilitation programs focus on the prevention of mental illness and offer treatment not only for acute psychiatric patients, but also for those who are at risk of developing a mental disorder or have recovered from one.The aim of this study was to determine the effects of a psychiatric rehabilitation program on individuals with different mood states. SUBJECTS AND METHODS: 600 patients with a history of affective disorder were tested at the time of admission to an Austrian inpatient psychiatric rehabilitation center. Data of extreme groups - patients who were depressed (n=59; BDI-II<9 and HAMD<8) or euthymic (n=59; BDI<18 and HAMD>19) at the time of therapy start - were analyzed. The participants completed the Maslach Burnout Inventory - General Survey, the Symptom Checklist - Revised and the Stress Coping Questionnaire at the beginning and the end of the 6-weeks rehabilitation program. RESULTS: After 6 weeks, both groups showed significantly less psychiatric symptoms (BDI-II, HAMD, SCL-90, and negative coping strategies (SVF). Importantly, work-related stress symptoms ("burnout" symptoms) improved significantly in the euthymic group. CONCLUSIONS: Euthymic patients seem to be able to focus on work-related stress symptoms including reduced emotional exhaustion through treatment, while currently depressed patients primarily benefit by an improvement in general psychiatric symptomatology. The results indicate the crucial role of mood state validated with standardized psychological questionnaires BDI-II and HAMD at time of admission to such programs. These findings could have implications on treatment decisions for psychiatric patients and assist in making a forecast concerning ability to recover and treatment prognosis.

Examining the Autonomic Nervous System in the Relationship among Heart Rate Variability, Stress Coping, and Cognitive Ability in Individuals with Psychiatric Disorders.

Depression is one of the most severe psychiatric disorders and affects patients on emotional, physical, and cognitive levels. Comorbid somatic conditions, such as cardiovascular diseases, are frequent and affect the quality of life, as well as mortality. Underlying maladaptive autonomic nervous system regulation influences emotional and cognitive processes. This study, thus, aimed to investigate the relationship among heart rate variability (HRV), self-reported coping strategies, executive function, and inhibition in individuals with psychiatric disorders. Data of 97 patients treated in a multi-professional psychiatric rehabilitation center for 6 weeks were analyzed. Subjects underwent psychological tests (Stress Coping Style Questionnaire, Emotional Competence Questionnaire, and Becks Depression Inventory-II), a cognitive test (Color-Word Interference Test), and a 24 h electrocardiogram to record HRV. Patients with higher depression scores had significantly lower HRVs and decreased self-reported abilities for stress coping. Depression severity did not affect cognitive inhibitory abilities. HRV was related to neither coping strategies nor cognitive inhibition abilities. However, lower HRV was related to higher values of Negative Stress Coping (ß = −0.21, p < 0.05). This relationship was fully mediated by depression severity (−4.79, 95% CI: −8.72, −0.72). HRV is not related to quantitative cognitive inhibition, but to the self-reported ability to cope with negative emotions in individuals with psychiatric disorders.

Bacterial urinary tract infection and subclinical bacteriuria in dogs receiving antineoplastic chemotherapy.

BACKGROUND: Immunosuppressive treatment with glucocorticoids and cyclosporine increases the risk for positive urine cultures (PUCs) in dogs. OBJECTIVE: To investigate the prevalence and incidence of PUC in dogs diagnosed with cancer and treated with antineoplastic chemotherapy while distinguishing between subclinical bacteriuria (SB) and urinary tract infection (UTI). ANIMALS: Forty-six client-owned dogs with nonurogenital cancer treated with antineoplastic chemotherapy. METHODS: Prospective observational longitudinal clinical study. Dogs in which a urine culture was performed before the start of and at least once during antineoplastic chemotherapy were included. A McNemar's test was used to investigate if the prevalence of PUC increased during antineoplastic chemotherapy. Positive urine cultures were categorized into SB and UTI and multiple PUCs from the same dog and category were grouped together as 1 episode of PUC. RESULTS: Urine culture was positive in 21/185 urine samples in 8/46 dogs. Antineoplastic chemotherapy did not influence the prevalence of PUC (P = 1.00), which was 11% (5/46 dogs; 95% confidence interval: 5-23%) before the start of and 13% (6/46 dogs; 95% confidence interval: 6-26%) during antineoplastic chemotherapy. Eight dogs had 10 episodes of PUC; 7/10 episodes were classified as SB, and in 3/10 episodes UTI (chronic prostatitis, prostatic abscess, and emphysematous cystitis) was diagnosed. Escherichia coli was the most common pathogen, isolated in 9/10 episodes. CONCLUSIONS AND CLINICAL IMPORTANCE: We did not find evidence that antineoplastic chemotherapy is a major predisposing factor for the development of PUC. Most dogs with PUC had SB.

Body Mass Index Predicts Decline in Executive Function in Bipolar Disorder: Preliminary Data of a 12-Month Follow-up Study.

INTRODUCTION: Obesity and associated risk factors have been linked to cognitive decline before. OBJECTIVES: In the present study, we evaluated potential cumulative negative effects of overweight and obesity on cognitive performance in euthymic patients with bipolar disorder (BD) in a longitudinal design. METHODS: Neurocognitive measures (California Verbal Learning Test, Trail Making Test [TMT] A/B, Digit-Symbol-Test, Digit-Span, d2 Test), anthropometrics (e.g., body mass index [BMI]), and clinical ratings (Hamilton Depression Scale, Young Mania Rating Scale) were collected over a 12-month observation period. Follow-up data of 38 patients with BD (mean age 40 years; 15 males, 23 females) were available. RESULTS: High baseline BMI predicted a decrease in the patient's performance in the Digit-Span backwards task measuring working memory performance. In contrast, cognitive performance was not predicted by increases in BMI at follow-up. Normal weight bipolar patients (n = 19) improved their performance on the TMT B, measuring cognitive flexibility and executive functioning, within 1 year, while overweight bipolar patients (n = 19) showed no change in this task. CONCLUSIONS: The results suggest that overweight can predict cognitive performance changes over 12 months.

PROVIT: Supplementary Probiotic Treatment and Vitamin B7 in Depression-A Randomized Controlled Trial.

Gut microbiota are suspected to affect brain functions and behavior as well as lowering inflammation status. Therefore, an effect on depression has already been suggested by recent research. The aim of this randomized double-blind controlled trial was to evaluate the effect of probiotic treatment in depressed individuals. Within inpatient care, 82 currently depressed individuals were randomly assigned to either receive a multistrain probiotic plus biotin treatment or biotin plus placebo for 28 days. Clinical symptoms as well as gut microbiome were analyzed at the begin of the study, after one and after four weeks. After 16S rRNA analysis, microbiome samples were bioinformatically explored using QIIME, SPSS, R and Piphillin. Both groups improved significantly regarding psychiatric symptoms. Ruminococcus gauvreauii and Coprococcus 3 were more abundant and ß-diversity was higher in the probiotics group after 28 days. KEGG-analysis showed elevated inflammation-regulatory and metabolic pathways in the intervention group. The elevated abundance of potentially beneficial bacteria after probiotic treatment allows speculations on the functionality of probiotic treatment in depressed individuals. Furthermore, the finding of upregulated vitamin B6 and B7 synthesis underlines the connection between the quality of diet, gut microbiota and mental health through the regulation of metabolic functions, anti-inflammatory and anti-apoptotic properties. Concluding, four-week probiotic plus biotin supplementation, in inpatient individuals with a major depressive disorder diagnosis, showed an overall beneficial effect of clinical treatment. However, probiotic intervention compared to placebo only differed in microbial diversity profile, not in clinical outcome measures.

C-Reactive Protein as a Possible Predictor of Trail-Making Performance in Individuals with Psychiatric Disorders.

Cognitive dysfunction is a prominent feature of psychiatric disorders. Studies have shown that systemic low-grade inflammation is crucial in the development of cognitive deficits across psychiatric disorders. The aim of this study was to further examine the role of inflammation and inflammatory mediators in cognitive function in psychiatric disorders. This study included 364 inpatients (53% females) with International Classification of Diseases (ICD)-10 F3 (affective disorders) and F4 (neurotic, stress-related, and somatoform disorders) diagnoses. The mean age was 52 years (22 to 69 years) and the median body mass index was 27.6. Cognitive function was assessed with the Color-Word Interference Test after Stroop and the Trail-Making Test A/B. Multiple linear regression models were calculated to assess the predictive value of C-reactive protein and the kynurenine/tryptophan ratio on cognitive function controlling for age, sex, education, premorbid verbal intelligence quotient illness duration, depressive symptoms, and obesity-related parameters (e.g., body mass index, high-density lipoprotein). Our data confirm that in patients with psychiatric disorders, C-reactive protein serum concentration is a relevant and important predictor of Trail-Making Test B performance, measuring cognitive flexibility. The effect size of this association did not change much after adding clinical and metabolic variables into the regression model. The kynurenine/tryptophan ratio was not related to cognitive test scores. The involvement of C-reactive protein as a peripheral inflammatory marker in cognitive flexibility and psychomotor processing speed in psychiatric illness can be concluded.

Personality Structure and Attachment in Bipolar Disorder.

BACKGROUND: An impairment of self and interpersonal functioning has an impact on coping strategies, regulation of affect and stress. Little is known so far about the impairment of personality functioning in patients with bipolar disorder (BD). The aim of this study is to assess the effects of personality structure and attachment in BD patients on the symptom burden. METHODS: Forty-six patients with the diagnosis of BD were assessed by the 12-item Operationalized Psychodynamic Diagnosis Structure Questionnaire (OPD-SQS), the short version of Experience in Close Relationship-revised (ECR-R-D), and the Brief Symptom Inventory-18 (BSI 18) to determine the level of personality functioning, attachment patterns, and symptom load. RESULTS: We observed positive correlations between personality difficulties, insecure attachment, and symptom load in patients with BD. A low level of structural integration and an insecure attachment style in patients with BD were accompanied by a significantly higher symptom load (r = 0.66, p ≤ 0.01). Interestingly, there were no significant differences in the structural integration (T(1.44) = -0.93, p = 0.357) and in the attachment style attachment related avoidance: (T(1,44) = 1.50, p = 0.140); attachment related anxiety (T(1,44) = -0.781, p = 0.439) of study participants with BD when compared to the normative value of the general population. LIMITATIONS: Our limitations are the small sample size of our group and the lack of a control group. CONCLUSION: In general, our results suggest that there is a link between personality structure and affective dynamics including depressive, anxiety, and somatization symptoms in BD. These findings underline the increasing importance of assessing personality structure and attachment for diagnosis and treatment planning of BD.

Probiotic Treatment in Individuals with Euthymic Bipolar Disorder: A Pilot-Study on Clinical Changes and Compliance.

The importance of the microbiome for psychological well-being has gained rising interest in the last decade. A strategy to examine the role of the microbiome in different diseases is the intake of supplements that modulate the gut microbiome. Despite promising results in animal studies, research in humans is sparse to date and especially in individuals with psychiatric disorders almost missing. The current report of the ProbioBIP-one pilot study aims at describing general effects of the intake of the probiotic OMNi-BiOTiC Stress repair® on psychological parameters as well as gastrointestinal symptoms and general compliance in a cohort of euthymic individuals with bipolar disorder (BD), receiving daily probiotic treatment over a time period of 3 months. Twenty-seven individuals with BD took part in the present study (mean age = 50.7 years, SD = 12.2; females 40.7%). In sum, there was a high compliance rate with 81.5% of the study participants completing all 3 study visits and 85% of planned probiotic ingestions taken. Gastrointestinal problems were prevalent in more than half of the patients at the time of inclusion (t1). Expectedly, in the whole cohort, a high proportion of study participants experienced changes concerning digestion during probiotic treatment, around one third reported positive changes (reduced flatulence and easier and more frequent bowel movements) after 1 month (t2) and further after 3 months (t3). In contrast, a smaller part of study participants reported gastrointestinal discomfort after 1 and after 3 months (mainly flatulence and obstipation). We found a significantly reduced cognitive reactivity to sad mood between t2 and t3 indicating that participants under probiotic supplementation perceived themselves to be less distracted by ruminative thoughts. Further changes in psychiatric symptoms were small due to the euthymic state and already low scoring at the time of inclusion. Nevertheless, we found a significant symptom reduction in the rating scales measuring manic symptoms. From a clinical point of view, probiotic supplementation might provide a well-tolerated tool to positively influence gastrointestinal quality of life as well as mental and somatic health, cognition and immune response and potentially have effects on psychiatric symptoms.

Physical health in individuals with psychiatric disorders in Austria.

INTRODUCTION: The association between severe psychiatric disorders and metabolic syndrome is well documented and goes along with a reduced life expectancy. The prevalence of medical comorbidities in individuals suffering from psychiatric disorders in Austria has not yet been examined; aim of this study was to analyze the prevalence of comorbid somatic disorder in individuals diagnosed with psychiatric disorders in Austria. METHODS: Patients (n = 600) with a life-time diagnosis of mood and anxiety disorders undergoing a six-week course of intensive treatment in a psychiatric rehabilitation center were recruited. Prevalent somatic and psychological conditions, anamnestic data, medical history, blood samples, clinical and psychological tests as well as medication were examined to determine somatic and psychiatric diagnoses. RESULTS: Metabolic disorders were highly prevalent especially in individuals diagnosed with affective disorders, respectively in bipolar disorder. Furthermore, obesity and thyroid dysfunction were found in about 40% of individuals diagnosed with bipolar disorder in the present study. Significant gender differences were found in CVD and hypertension with higher prevalence in men, while thyroid dysfunction occurred more often in women also compared to the general female population. CONCLUSIONS: Characterizing somatic comorbidity in individuals with psychiatric disorders can stimulate research to better understand possible shared etiologic factors and has public health implications for improving models of care. This could have a positive effect on the course of mental disorders, and additionally improve social integration and life expectancy. Knowledge about sex differences should be used to further improve individualized treatment of individuals with psychiatric disorders.

Weight Gain During Treatment of Bipolar Disorder (BD)-Facts and Therapeutic Options.

Bipolar disorder (BPD) is a mood disorder, which is characterized by alternating affective states, namely (hypo)mania, depression, and euthymia. Evidence is growing that BPD has indeed a biologic substrate characterized by chronic inflammation, oxidative stress, and disturbed energy metabolism. Apart from this, there is obviously a hereditary component of this disease with multi-genetic factors. Most probably a susceptibility threshold favors the outbreak of clinical disease after a cascade of stress events that remain to be elucidated in more detail. Evidence is also growing that weak points in brain energy metabolism contribute to outbreak and severity of BPD. Conventional psychopharmacologic therapy must be reassessed under the aspects of weight cycling and development of central obesity as a deterioration factor for a worse clinical course leading to early cardiovascular events in BPD subgroups.

Branched-chain amino acids are associated with metabolic parameters in bipolar disorder.

Objectives: An important aspect of bipolar disorder (BD) research is the identification of biomarkers pertaining to the somatic health state. The branched-chain essential amino acids (BCAAs), viz valine, leucine and isoleucine, have been proposed as biomarkers of an individual's health state, given their influence on protein synthesis and gluconeogenesis inhibition.Methods: BCAA levels of 141 euthymic/subsyndromal individuals with BD and 141 matched healthy controls (HC) were analysed by high-pressure lipid chromatography and correlated with clinical psychiatric, anthropometric and metabolic parameters.Results: BD and HC did not differ in valine and isoleucine, whereas leucine was significantly lower in BD. Furthermore, correlations were found between BCAAs and anthropometric and glucose metabolism data. All BCAAs correlated with lipid metabolism parameters in females. There were no associations between BCAAs and long-term clinical parameters of BD. A negative correlation was found between valine and Hamilton Depression-Scale, and Beck Depression Inventory II, in male individualsConclusions: Our results indicate the utility of BCAAs as biomarkers for the current state of health, also in BD. As BD individuals have a high risk for overweight/obesity, in association with comorbid medical conditions (e.g. cardiovascular diseases or insulin resistance), health state markers are urgently required. However, no illness-specific associations were found in this euthymic/subsyndromal BD group.

Adiponectin is decreased in bipolar depression.

Objectives: Bipolar disorder (BD) is often accompanied by medical comorbidities, which affect illness course and prognosis. Adipokines may not only be involved in the aetiopathogenetic mechanisms of these comorbidities; there might be an association between adipokines and the neuropsychiatric core features of BD such as mood disturbances and cognitive deficits.Methods: In this investigation, fasting blood samples from 120 individuals with BD (75 euthymic and 45 with mild depressive symptoms) and 68 control subjects were taken and adiponectin and leptin concentrations were analysed.Results: We found that, in female participants, adiponectin levels differed significantly between patients and controls indicating lower levels in individuals with BD, even after controlling for BMI (F(1,92) = 4.65, P = 0.034, partial η2 = 0.05). After stratification by mood status we found a significant difference in adiponectin between controls, euthymic and depressive patients (F(2, 180) = 4.90, P = 0.008, partial η2 = 0.05).Conclusions: This investigation confirms previous findings of an association between low adiponectin levels and depressive state in individuals with BD. Beyond its immediate effect on central nervous system function, adiponectin might interfere with pathophysiological mechanisms of BD and its somatic comorbidities via involvement in metabolic and inflammatory processes.

Psychopathic personality factor "Fearless dominance" is related to low self-reported stress-levels, fewer psychiatric symptoms, and more adaptive stress coping in psychiatric disorders.

The aim of this cross-sectional study was to test the idea that the psychopathic trait "Fearless dominance" (FD) may be associated with reduced psychological stress symptoms and better stress coping strategies in psychiatric patients, whereas the factor "Self-centered impulsivity" (SCI) may be associated with more stress and maladaptive stress coping. The investigation included 626 individuals with psychiatric disorders treated in a psychiatric rehabilitation program. The participants were tested with the Psychopathic Personality Inventory Revised (PPI-R) and completed several clinical scales measuring stress experience and stress coping (Symptom-Checklist Revised, Trier Inventory for Chronic Stress, The Stress Coping Style Questionnaire 78). Consistent with the hypothesis, structural equation modeling results showed that self-reported stress levels and adaptive stress coping strategies might be explained by psychopathic FD traits in the psychiatric sample. Supplemental subscale analyses showed that especially the PPI-R scales Stress Immunity and Social Influence were positively related to adaptive stress coping. The second model of SCI did not fit our data well. In conclusion, individuals with psychopathic FD traits may experience less stress symptoms during residential care. Well-designed prospective trials may ultimately answer the question whether psychopathic traits could be viewed as serving a buffer function in the development of depression.

Endoplasmic reticulum stress in bipolar disorder? - BiP and CHOP gene expression- and XBP1 splicing analysis in peripheral blood.

BACKGROUND: Endoplasmic Reticulum stress activates the Unfolded Protein Response, which is partially impaired in Bipolar Disorder (BD) according to previous in-vitro studies. Thus, BiP and CHOP gene expression and XBP1 splicing were analyzed in peripheral blood of study participants with BD and controls. METHODS: RNA was isolated from fasting blood of study participants with BD (n = 81) and controls (n = 54) and reverse transcribed into cDNA. BiP and CHOP gene expression was analyzed with quantitative RT-PCR. Atypical splicing of XBP1 mRNA was measured by semi-quantitative RT-PCR, gel-electrophoresis and densitometry. ANCOVAs with the covariates age, BMI, sex, lithium and anticonvulsants intake were used with SPSS. Bonferroni correction was used to correct for multiple testing (adjusted p = 0.0083). RESULTS: BiP gene expression was significantly higher in BD than in controls (F(1/128) = 10.076, p = 0.002, Partial η2 = 0.073). Total XBP1 (F(1/126) = 9.550, p = 0.002, Partial η2 = 0.070) and unspliced XBP1 (F(1/128)= 8.803, p= 0.004, Patial η2 = 0.065) were significantly decreased in BD. Spliced XBP1 (F(1/126) = 5.848, p = 0.017, Partial η2 = 0.044) and the ratio spliced XBP1/ unspliced XBP1 did not differ between BD and controls (F(1/126) = 0.599, p = 0.441, Partial η2 = 0.005). Gene expression did not differ between euthymia, depression and mania. DISCUSSION: BiP gene expression was significantly higher in BD compared to controls. Total and unspliced XBP1 were significantly lower in BD than in the control group. Thus, both genes may be considered as putative trait markers. Nevertheless, XBP1 splicing itself did not differ between both groups.

Practicable methods for histological section thickness measurement in quantitative stereological analyses.

The accuracy of quantitative stereological analysis tools such as the (physical) disector method substantially depends on the precise determination of the thickness of the analyzed histological sections. One conventional method for measurement of histological section thickness is to re-embed the section of interest vertically to its original section plane. The section thickness is then measured in a subsequently prepared histological section of this orthogonally re-embedded sample. However, the orthogonal re-embedding (ORE) technique is quite work- and time-intensive and may produce inaccurate section thickness measurement values due to unintentional slightly oblique (non-orthogonal) positioning of the re-embedded sample-section. Here, an improved ORE method is presented, allowing for determination of the factual section plane angle of the re-embedded section, and correction of measured section thickness values for oblique (non-orthogonal) sectioning. For this, the analyzed section is mounted flat on a foil of known thickness (calibration foil) and both the section and the calibration foil are then vertically (re-)embedded. The section angle of the re-embedded section is then calculated from the deviation of the measured section thickness of the calibration foil and its factual thickness, using basic geometry. To find a practicable, fast, and accurate alternative to ORE, the suitability of spectral reflectance (SR) measurement for determination of plastic section thicknesses was evaluated. Using a commercially available optical reflectometer (F20, Filmetrics®, USA), the thicknesses of 0.5 µm thick semi-thin Epon (glycid ether)-sections and of 1-3 µm thick plastic sections (glycolmethacrylate/ methylmethacrylate, GMA/MMA), as regularly used in physical disector analyses, could precisely be measured within few seconds. Compared to the measured section thicknesses determined by ORE, SR measures displayed less than 1% deviation. Our results prove the applicability of SR to efficiently provide accurate section thickness measurements as a prerequisite for reliable estimates of dependent quantitative stereological parameters.

Chiral molecules adsorbed on a solid surface: Tartaric acid diastereomers and their surface explosion on Cu(111).

The adsorption of diastereoisomers of tartaric acid, namely, meso (R,S)-tartaric acid, (R,R)-tartaric acid, and the racemic mixture of (R,R) and (S,S) tartaric acid on the (111) surface of a copper single crystal has been studied by means of reflection-absorption IR Spectroscopy, X-ray photoelectron spectroscopy, low-energy electron diffraction, and thermal desorption spectroscopy. Two distinct adsorption modes are identified for all three adsorbate systems. All molecules undergo an identical thermally induced autocatalytic decomposition reaction above 510 K. The pure enantiomers show 2D chiral long-range ordered structures of opposite handedness.

Ranking the Stability of Transition-Metal Complexes by On-Surface Atom Exchange.

Surface-adsorbed macrocycles exhibit a number of interesting physical and chemical properties; many of them are determined by their transition-metal centers. The hierarchical exchange of the central metal atom in such surface-adsorbed complexes is demonstrated, specifically in the porphyrin-like macrocycle pyrphyrin adsorbed on Cu(111). Using scanning tunneling microscopy and X-ray photoelectron spectroscopy, we show that Cu as central metal atom is easily exchanged with Ni or Fe atoms supplied in trace amounts to the surface. Atom exchange of Ni centers with Fe atoms also occurs, with moderate yield. These results allow ranking the stability of the surface-adsorbed Cu, Ni, and Fe complexes. The fact that the atom exchange occurs at 423 K shows that surface-adsorbed macrocycles can be surprisingly easily transformed.