Artificial Intelligence in Orthodontics: Critical Review

With increasing digitalization in orthodontics, certain orthodontic manufacturing processes such as the fabrication of indirect bonding trays, aligner production, or wire bending can be automated. However, orthodontic treatment planning and evaluation remains a specialist's task and responsibility. As the prediction of growth in orthodontic patients and response to orthodontic treatment is inherently complex and individual, orthodontists make use of features gathered from longitudinal, multimodal, and standardized orthodontic data sets. Currently, these data sets are used by the orthodontist to make informed, rule-based treatment decisions. In research, artificial intelligence (AI) has been successfully applied to assist orthodontists with the extraction of relevant data from such data sets. Here, AI has been applied for the analysis of clinical imagery, such as automated landmark detection in lateral cephalograms but also for evaluation of intraoral scans or photographic data. Furthermore, AI is applied to help orthodontists with decision support for treatment decisions such as the need for orthognathic surgery or for orthodontic tooth extractions. One major challenge in current AI research in orthodontics is the limited generalizability, as most studies use unicentric data with high risks of bias. Moreover, comparing AI across different studies and tasks is virtually impossible as both outcomes and outcome metrics vary widely, and underlying data sets are not standardized. Notably, only few AI applications in orthodontics have reached full clinical maturity and regulatory approval, and researchers in the field are tasked with tackling real-world evaluation and implementation of AI into the orthodontic workflow.

Quality of life in patients with hypoparathyroidism receiving standard treatment: an updated systematic review

PURPOSE

Hypoparathyroidism is defined by hypocalcemia with inappropriately normal or low parathyroid hormone levels. The current standard treatment consists of lifelong calcium and/ or vitamin D supplementation. Even while on stable treatment regimens, hypoparathyroid patients might still suffer from symptoms that can negatively impact their quality of life.

METHODS

A systematic literature review to identify the current knowledge regarding quality of life in patients with hypoparathyroidism receiving standard treatment was performed on November 1st, 2023. PubMed as well as Web of Science were searched. The systematic review is registered in PROSPERO (#CRD42023470924).

RESULTS

After removal of duplicates, 398 studies remained for title and abstract screening, after which 30 were included for full-text screening. After exclusion of seven studies with five studies lacking a control population, one using a non-validated questionnaire, and one being a subsample of the larger included study, 23 studies were included in this systematic review. The majority of the included studies used a guideline-conform definition of hypoparathyroidism, and the SF-36 was the most often applied tool. Almost all studies (87%) reported statistically significantly lower scores in at least one quality of life domain compared to a norm population or controls.

CONCLUSION

Patients with hypoparathyroidism receiving standard treatment report impairments in quality of life. The reasons for these impairments are probably multifaceted, making regular monitoring and the inclusion of various professionals necessary.

Cumulative social disadvantage and cardiovascular disease burden and mortality

AIMS

To investigate the association between cumulative social disadvantage and cardiovascular burden and mortality in a large cohort of the general population.

METHODS AND RESULTS

Cross-sectional (n = 15 010, aged 35 to 74 years, baseline investigation period 2007 to 2012) and longitudinal data (5- and 10-year follow-ups from 2012 to 2022) from the Gutenberg Health Study were used to investigate the association between individual socioeconomic status (SES, measured via a validated questionnaire) and cardiovascular disease (CVD, composite of atrial fibrillation, coronary artery disease, myocardial infarction, stroke, chronic heart failure, peripheral artery disease, and/or venous thromboembolism) risk and mortality. Subjects with prevalent CVD had a lower SES sum score, as well as lower education, occupation, and household net-income scores (all P < 0.0001). Logistic regression analysis showed that a low SES (vs. high, defined by validated cut-offs) was associated with 19% higher odds of prevalent CVD [odds ratio (OR) 1.19, 95% CI 1.01; 1.40] in the fully adjusted model. At 5-year follow-up, low SES was associated with both increased cardiovascular [hazard ratio (HR) 5.36, 2.24; 12.82] and all-cause mortality (HR 2.23, 1.51; 3.31). At 10-year follow-up, low SES was associated with a 68% higher risk of incident CVD (OR 1.68, 1.12; 2.47) as well as 86% higher all-cause mortality (HR 1.86, 1.55; 2.24). In general, the education and occupation scores were stronger related to risk of CVD and death than the household net-income score. Low SES was estimated to account for 451.45 disability-adjusted life years per 1000 people (years lived with disability 373.41/1000 and years of life lost 78.03/1000) and an incidence rate of 11 CVD cases and 3.47 CVD deaths per 1000 people per year. The population attributable fraction for CVD incidence after 5 years was 4% due to low SES.

CONCLUSION

Despite universal healthcare access, cumulative social disadvantage remains associated with higher risk of CVD and mortality. Dimensions of education and occupation, but not household net income, are associated with outcomes of interest.

Impairments in quality of life and predictors of symptom burden in patients with hypoparathyroidism: results from a population-based survey

PURPOSE

To investigate the quality of life (QoL) in patients with hypoparathyroidism (hypoPT) compared to the general population and to identify sociodemographic and clinical factors that are associated with symptom burden.

METHODS

Patients with a diagnosis of hypoPT participated in an online survey. Information regarding the survey was distributed by treating physicians or a self-help organization. Quality of life was assessed using the EORTC QLQ-C30 and symptom burden using the Hypoparathyroid Patient Questionnaire (HPQ28). Multivariate linear regression analysis was used to compare QoL of hypoPT patients with the general population (adjusted for age, sex, education)and to identify factors associated with symptom burden.

RESULTS

Altogether, 264 hypoPT patients provided information on QoL and symptom burden. HypoPT was associated with worse cognitive (β = -15.9; p < 0.01) and emotional functioning (β = -12.3; p = 0.04) compared to the general population. The highest symptom burden in hypoPT patients was observed for the domains loss of vitality (mean: 61.4; SD: 21.9), pain and cramps (mean: 43.7; SD: 26.5), and numbness and tingling sensations (mean: 38.9; SD: 30.0). Female gender was associated with a higher symptom burden across all nine domains of the HPQ28, while longer disease duration was associated with a lower symptom burden in neurovegetative symptoms, loss of vitality, depression and anxiety, and depressive symptoms.

CONCLUSION

HypoPT patients have impaired QoL compared to the general population. Being female is strongly associated with high symptom burden.

Hypoparathyroidism - management, information needs, and impact on daily living from the patients' perspective: results from a population-based survey

PURPOSE

Hypoparathyriodism (hypoPT) is a rare endocrine disorder. It is not known how hypoPT is managed in Germany or whether patients have unmet information needs or impairments in their daily living.

METHODS

HypoPT patients at a minimum of 6 months' post-diagnosis were invited to participate in an online survey through their treating physician or through patient organizations. An extensive questionnaire, which was developed and pilot-tested with hypoPT patients, was administered.

RESULTS

A total of 264 patients with a mean age of 54.5 years (SD: 13.3), 85.2% female and 92% with postsurgical hypoPT, participated in the study. In total, 74% of the patients reported regular monitoring of serum calcium at least every 6 months, with lower control frequencies for phosphate (47%), magnesium (36%), creatinine (54%), and parathyroid hormone (50%), and 24-h urine calcium excretion (36%) on a yearly basis. Information on symptoms of hypo- and hypercalcemia was available in 72 and 45% of the patients. Information needs were related to the disease and its treatment as well as to nutrition, physical activities/sports, and support opportunities. Statistically significant differences for all information needs in association with symptom burden were observed. Hospitalization for hypocalcemia was reported by 32%, nutritional impairments (38%) or impact on work ability (52%) was available among patients with hypoPT.

CONCLUSION

HypoPT patients experience impairments in daily living and report unmet information needs. Patient and physician education regarding hypoPT is one of the key concepts for improving the management of patients with hypoPT.

Multi-modal deep learning for automated assembly of periapical radiographs

OBJECTIVES

Periapical radiographs are oftentimes taken in series to display all teeth present in the oral cavity. Our aim was to automatically assemble such a series of periapical radiographs into an anatomically correct status using a multi-modal deep learning model.

METHODS

4,707 periapical images from 387 patients (on average, 12 images per patient) were used. Radiographs were labeled according to their field of view and the dataset split into a training, validation, and test set, stratified by patient. In addition to the radiograph the timestamp of image generation was extracted and abstracted as follows: A matrix, containing the normalized timestamps of all images of a patient was constructed, representing the order in which images were taken, providing temporal context information to the deep learning model. Using the image data together with the time sequence data a multi-modal deep learning model consisting of two residual convolutional neural networks (ResNet-152 for image data, ResNet-50 for time data) was trained. Additionally, two uni-modal models were trained on image data and time data, respectively. A custom scoring technique was used to measure model performance.

RESULTS

Multi-modal deep learning outperformed both uni-modal image-based learning (p<0.001) and time-based learning (p<0.05). The multi-modal deep learning model predicted tooth labels with an F1-score, sensitivity and precision of 0.79, respectively, and an accuracy of 0.99. 37 out of 77 patient datasets were fully correctly assembled by multi-modal learning; in the remaining ones, usually only one image was incorrectly labeled.

CONCLUSIONS

Multi-modal modeling allowed automated assembly of periapical radiographs and outperformed both uni-modal models. Dental machine learning models can benefit from additional data modalities.

CLINICAL SIGNIFICANCE

Like humans, deep learning models may profit from multiple data sources for decision-making. We demonstrate how multi-modal learning can assist assembling periapical radiographs into an anatomically correct status. Multi-modal learning should be considered for more complex tasks, as clinically a wealth of data is usually available and could be leveraged.

Effects of care of multimorbid patients in general practices by advanced practice nurses (FAMOUS): study protocol for a nonrandomized controlled trial

BACKGROUND

Multimorbidity is a common phenomenon among patients treated in general practices. Key challenges within this group include functional difficulties, polypharmacy, treatment burden, fragmentation of care, reduced quality of life and increased health care utilization. These problems cannot be solved in the short consultation time of a general practitioner (GP) since there is an increasing shortage of GPs. In many countries, advanced practice nurses (APNs) are successfully integrated into primary health care for multimorbid patients. The objective of this study is to examine whether the integration of APNs in the primary care of multimorbid patients in Germany leads to optimized care of the target group and to a reduction in the workload of the GPs.

METHODS

The intervention includes the integration of APNs into the care for multimorbid patients in general practice for twelve months. Qualifications for APNs include a master's level academic degree and 500 hours of project-specific training. Their tasks include in-depth assessment, preparation, implementation, monitoring and evaluation of a person-centred and evidence-based care plan. In this nonrandomized controlled trial, a prospective multicentre mixed methods study will be performed. The main inclusion criterion was the cooccurrence of three chronic diseases. For data collection in the intervention group (n = 817), routine data from health insurance companies and association of statutory health insurance physicians (ASHIP) will be used, as well as qualitative interviews. In addition, the intervention will be assessed through documentation of the care process and standardized questionnaires using a longitudinal design. The control group (n = 1634) will receive standard care. For the evaluation, routine data from health insurance companies are matched at a ratio of 1:2. Outcomes will be measured using emergency contacts and GP visits, treatment costs, health status of the patients and the satisfaction of parties involved. The statistical analyses will include Poisson regression to compare outcomes between the intervention and control groups. Descriptive and analytical statistical methods will be used in the longitudinal analysis of the intervention group data. Cost analysis will compare total costs and subgroup costs between the intervention and control groups. Qualitative data will be analysed using content analysis.

DISCUSSION

Challenges to this protocol could include the political and strategic environment as well as the planned number of participants.

TRIAL REGISTRATION

DRKS00026172 on DRKS.

The INDICATE Knee expectations survey detects general patient treatment goals for total knee arthroplasty and the influence of demographic factors on patients expectations

PURPOSE

Post-operative outcome after total knee arthroplasty (TKA) in the treatment of end-stage osteoarthritis correlates strongly with pre-operative impairment-driven patient treatment goals. However, a clinical tool for measuring patient treatment goals in correlation to impairments is still missing, which impedes patient-oriented indication in TKA.

METHODS

Patients scheduled for TKA were recruited in four German hospitals. All patients were handed the INDICATE Knee Score pre-operatively. The score contains 31 treatment goals with respective impairments, subdivided into seven categories. They were asked to rank all treatment goals and impairments on a 3-point scale. Treatment goals and impairments were then checked for frequency of occurrence. Correlation of goal and impairment was tested. Analysis for associations of treatment goals and different cohort characteristics (age, sex, BMI) was conducted.

RESULTS

1.298 patients were included in the study. Seven treatment goals were categorised as "main goal" from more than 90% of all patients ("knee pain", "range of motion", "walking distance", "overall physical function", "climbing stairs", "quality of life", "implant survival"). Comparing age groups, there were significant associations towards higher expectations regarding working, physical and sports related treatment goals in younger patients (< 65y) ("ability to work" (P ≤ .001), "sports activities" (P ≤ .001), "sex life" (P ≤ .001), "dependence on help of others" (P = .015), "preventing secondary impairment" (P = .03), "dependence on walking aids" (P = .005)). Higher BMI resulted in increasing relevance of "weight reduction" (P ≤ .001), "climbing stairs" (P = .039) "global health status" (P = .015) and "long standing" (P = .007) as a "main goal". Analysis for differences in treatment goals regarding sex showed women choosing more treatment goals as "main goals" than men.

CONCLUSION

Seven treatment goals which were expected by > 90% in our collective can be classified as general treatment goals for TKA. Demographic factors (age, sex, BMI) were significantly associated with patients' expectations for TKA. We conclude physicians should clearly assess their patients' demands prior to TKA to maximise post-operative outcome.

LEVEL OF EVIDENCE

Prognostic Level III.

Determinants of mammography screening participation-a cross-sectional analysis of the German population-based Gutenberg Health Study (GHS)

PURPOSE

We investigated the association between social inequality and participation in a mammography screening program (MSP). Since the German government offers mammography screening free of charge, any effect of social inequality on participation should be due to educational status and not due to the financial burden.

METHODS

The 'Gutenberg Health Study' is a cohort study in the Rhine-Main-region, Germany. A health check-up was performed, and questions about medical history, health behavior, including secondary prevention such as use of mammography, and social status are included. Two indicators of social inequality (equivalence income and educational status), an interaction term of these two, and different covariables were used to explore an association in different logistic regression models.

RESULTS

A total of 4,681 women meeting the inclusion criteria were included. Only 6.2% never participated in the MSP. A higher income was associated with higher chances of ever participating in a mammography screening (odds ratios (OR): 1.67 per €1000; 95%CI:1.26-2.25, model 3, adjusted for age, education and an interaction term of income and education). Compared to women with a low educational status, the odds ratios for ever participating in the MSP was lower for the intermediate educational status group (OR = 0.64, 95%CI:0.45-0.91) and for the high educational status group (0.53, 95%CI:0.37-0.76). Results persisted also after controlling for relevant confounders.

CONCLUSIONS

Despite the absence of financial barriers for participation in the MSP, socioeconomic inequalities still influence participation. It would be interesting to examine whether the educational effect is due to an informed decision.

What are predictors of impaired quality of life in patients with hypoparathyroidism?

CONTEXT

Hypoparathyroidism (hypoPT) is a rare endocrine disorder. Little is known about what factors are associated with potential quality of life (QOL) impairments.

DESIGN

HypoPT patients at a minimum of 6 months' post diagnosis were invited to participate in an online survey through their treating physician or through self-help organisations METHODS: Impairments of clinical importance in QOL were considered present if the score of the respective functioning scale of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 exceeded a pre-defined threshold. Symptom burden was assessed using the HPQ-28. Multivariate logistic regression was used to identify factors associated with impairments in QOL.

RESULTS

Data were available for 264 hypoPT patients. Impairments of clinical importance in QOL were reported for 40.4% in role functioning (RF), 40.6% in social functioning (SF), 60.8% in physical functioning (PF), 65.5% in cognitive functioning (CF) and 76.0% in emotional functioning (EF). Higher odds for reporting impaired QOL were seen for higher symptom burden (for almost all domains) and for being unable to work (for PF, RF and SF). Surgery for thyroid cancer being the cause of hypoPT was associated with lower odds in PF for patients and in PF and CF for patients with surgery for other thyroid-related diseases being the hypoPT cause.

CONCLUSIONS

HypoPT needs to be recognised as a disease which might be associated with impaired QOL and affect daily living. Symptom management is crucial for improving QOL in hypoPT patients but socioeconomic factors like work-ability need to be considered when treating hypoPT patients.

Hängen die Stundenkontingente für ambulante Psychotherapie zur Behandlung von Depressionen mit deren Schweregrad zusammen?

Fragestellung

Vor dem Hintergrund der Debatte um eine mögliche Festlegung des Leistungsumfangs für ambulante Psychotherapie anhand der Diagnose haben wir untersucht, ob in der aktuellen Versorgungspraxis bei Patienten mit Depressionen die Anzahl der beantragten sowie die der vom Gutachter befürworteten Stunden mit dem Schweregrad der Erkrankung zusammenhängen.

Methode

Aus einer Zufallsstichprobe von 1000 Anträgen auf Kostenübernahme für ambulante analytische oder tiefenpsychologisch fundierte Psychotherapie wurden jene herausgesucht, in denen eine Depressionsdiagnose mit Schweregradeinschätzung (ICD-10 F32 oder F33) entweder im Bericht oder auf dem Antragsformular kodiert worden war. Die Zahl der beantragten und der befürworteten Stunden pro Antrag wurde extrahiert. Bei Umwandlungs- und Fortführungsanträgen wurden dabei auch die im Vorfeld stattgefundenen Therapiestunden berücksichtigt. Ein möglicher Zusammenhang des Schweregrads der Depression mit der Zahl der beantragten bzw. der vom Gutachter befürworteten Stunden wurde anhand von Spearman-Rangkorrelationen überprüft.

Ergebnisse

Insgesamt 521 Anträge (52 %) enthielten eine F32- und/oder eine F33-Diagnose. Davon waren 63 (12 %) als leicht kodiert, 349 (67 %) als mittelgradig und 50 (10 %) als schwer.

Im Median wurden 75 h bei leichter sowie je 50 h bei mittelgradiger bzw. bei schwerer Depression beantragt, wobei die Zahlen innerhalb der Gruppen stark variierten (10 bis 327 h) und der Zusammenhang zwischen Schweregrad und beantragter Stundenzahl gering war (Rho −0,10).

Die befürworteten Stundenkontingente waren im Median 74 (leichte Depression), 50 (mittelgradig) und 50 (schwer) Stunden, auch hier war die Spannweite hoch (0 bis 327 h) und die Korrelation gering (Rho −0,11).

Diskussion

Es gibt keine Anhaltspunkte dafür, dass Psychotherapeuten die benötigten Stundenkontingente allein anhand des Schweregrads der Diagnose festlegen.

Quality of Life Assessment for Tonsillar Infections and Their Treatment

Background and Objectives: Tonsillar infections are a common reason to see a physician and lead to a reduction in the patients’ health-related quality of life (HRQoL). HRQoL may be an important criterion in decision science and should be taken into account when deciding when to perform tonsillectomy, especially for chronic tonsillitis. The aim of this study was to determine the health utility for different states of tonsillar infections. Materials and Methods: Hospitalized patients with acute tonsillitis or a peritonsillar abscess were asked about their HRQoL with the 15D questionnaire. Patients who had undergone tonsillectomy were reassessed six months postoperatively. Results: In total, 65 patients participated in the study. The health states of acute tonsillitis and peritonsillar abscess had both a utility of 0.72. Six months after tonsillectomy, the mean health utility was 0.95. Conclusions: Our study confirms a substantial reduction in utility due to tonsillar infections. Tonsillectomy significantly improves the utility and therefore HRQoL six months after surgery.

Benchmarking atlas-level data integration in single-cell genomics

Single-cell atlases often include samples that span locations, laboratories and conditions, leading to complex, nested batch effects in data. Thus, joint analysis of atlas datasets requires reliable data integration. To guide integration method choice, we benchmarked 68 method and preprocessing combinations on 85 batches of gene expression, chromatin accessibility and simulation data from 23 publications, altogether representing >1.2 million cells distributed in 13 atlas-level integration tasks. We evaluated methods according to scalability, usability and their ability to remove batch effects while retaining biological variation using 14 evaluation metrics. We show that highly variable gene selection improves the performance of data integration methods, whereas scaling pushes methods to prioritize batch removal over conservation of biological variation. Overall, scANVI, Scanorama, scVI and scGen perform well, particularly on complex integration tasks, while single-cell ATAC-sequencing integration performance is strongly affected by choice of feature space. Our freely available Python module and benchmarking pipeline can identify optimal data integration methods for new data, benchmark new methods and improve method development.

scCODA is a Bayesian model for compositional single-cell data analysis

Compositional changes of cell types are main drivers of biological processes. Their detection through single-cell experiments is difficult due to the compositionality of the data and low sample sizes. We introduce scCODA ( https://github.com/theislab/scCODA ), a Bayesian model addressing these issues enabling the study of complex cell type effects in disease, and other stimuli. scCODA demonstrated excellent detection performance, while reliably controlling for false discoveries, and identified experimentally verified cell type changes that were missed in original analyses.

[Impact of the COVID-19 pandemic on speech therapy for children with Speech and Language Disorders]

OBJECTIVE

 In December 2019, the COVID-19 pandemic began to spread around the world and caused massive restrictions in our daily life. Many educational facilities and practices delivering speech therapy were temporally closed (so-called lockdown). Children with a speech and language disorder were forced to pause their therapy. The aim of this study was to describe if and how speech therapy was delivered during lockdown and what psychological burden was associated to affected parents.

MATERIAL AND METHODS

 Parents of children with a speech and language disorder were asked about their child´s therapy during lockdown and about their fears and worries associated with it.

RESULTS

 For 17 patients speech therapy was paused during lockdown while 20 patients could continue their therapy. Children speaking a language other than German had a higher risk for having their therapy paused during lockdown (Odds ratio = 5.11, with 95 % confidence interval = 1.09-32.54). Parents whose children did not receive speech therapy during lockdown were more worried about their child's development.

CONCLUSIONS

 There is no common concept on how speech therapy can be delivered safely during lockdown. Possible barriers to healthcare might be more pronounced during the pandemic and parents experience a high psychosocial burden.

Financial toxicity in sarcoma patients and survivors in Germany: results from the multicenter PROSa study

Purpose

Cancer patients have been shown to frequently suffer from financial burden before, during, and after treatment. However, the financial toxicity of patients with sarcoma has seldom been assessed. Therefore, the aim of this study was to evaluate whether financial toxicity is a problem for sarcoma patients in Germany and identify associated risk factors.

Methods

Patients for this analysis were obtained from a multicenter prospective cohort study conducted in Germany. Using the financial difficulties scale of the EORTC QLQ-C30, financial toxicity was considered to be present if the score exceeded a pre-defined threshold for clinical importance. Comparisons to an age- and sex-matched norm population were performed. A multivariate logistic regression using stepwise backward selection was used to identify factors associated with financial toxicity.

Results

We included 1103 sarcoma patients treated in 39 centers and clinics; 498 (44.7%) patients reported financial toxicity. Sarcoma patients had 2.5 times the odds of reporting financial difficulties compared to an age- and sex-matched norm population. Patient age < 40 and > 52.5 years, higher education status, higher income, and disease progression (compared to patients with complete remission) were associated with lower odds of reporting financial toxicity. Receiving a disability pension, being currently on sick leave, and having a disability pass were statistically significantly associated with higher odds of reporting financial toxicity.

Conclusion

Financial toxicity is present in about half of German sarcoma patients, making it a relevant quality of life topic for patients and decision-makers.

Management of thyroid cancer: results from a German and French patient survey

OBJECTIVE

Various national and international guidelines for the management of thyroid cancer exist. The aim of this survey was to evaluate whether patients experience differences regarding the management of thyroid cancer in Germany and in France.

METHODS

An online survey addressing diagnosis, treatment, aftercare, and information needs of thyroid cancer survivors was set up by the German and the French nationwide thyroid cancer self-help organizations. The survey consisted of up to 70 questions depending on the given answers. Descriptive statistics and univariate comparisons, if appropriate, for comparing thyroid cancer survivors in Germany and France were performed.

RESULTS

In total, 1254 thyroid cancer survivors took part in the survey, of whom 1005 were included in the analysis, 618 from Germany and 387 from France. Remarkable differences between the two countries were observed regarding waiting times, diagnostics, surgical complications, radioiodine treatment, and aftercare of the patients. A high disease burden and lack of information regarding the condition and its treatment were reported in both countries.

CONCLUSION

This large survey showed that despite various guidelines for the management of thyroid cancer, thyroid cancer survivors' experiences are noticeably different between two big European countries. Lack of information and unmet needs are still tasks to be addressed in order to optimize thyroid cancer care.

The PROMISE study protocol: a multicenter prospective study of process optimization with interdisciplinary and cross-sectoral care for German patients receiving hip and knee endoprostheses

Background and purpose - Knee and hip replacement are common and increasing procedures, and an optimized care process that could be implemented in different settings would be useful. The PROMISE trial investigates whether a new care process works equally in different German settings and how the results compare with current non-standardized care.Patients and methods - This multi-center prospective mixed-method study includes 2,000 German patients receiving arthritis-related hip or knee endoprostheses. An interdisciplinary and cross-sectoral care process was developed and implemented in 3 German hospitals with different levels of care, and corresponding rehabilitation centers were included to bridge the gap after acute care.Duration and outcome - The PROMISE trial recruited patients between May 2018 and March 2020. Follow-up will end in February 2021. Assessments are performed at: examination on clinical indication, 1 week before surgery, on the day of surgery, at the end of hospitalization, end of the rehabilitation program, and 3 months, 6 months, and 12 months after surgery. Outcomes include patient-reported outcomes, medical examination findings, and routinely collected data regarding the surgery and complications. Guideline-based interviews are conducted with selected patients and care partners. The primary endpoint is the presence of chronic pain at 12 months after surgery. Secondary endpoints are the number of recognized pre-existing conditions, physical activity at 12 months after surgery, use of medical services, quality of life, and interactions between care partners.Trial registration - The trial is registered with the German Clinical Trials Register (https://www.drks.de; DRKS00013972; March 23, 2018).

Quality of Life in Patients With Hypoparathyroidism After Treatment for Thyroid Cancer

PURPOSE

Surgical complications such as hypoparathyroidism (HPT) or vocal cord palsy are seldom assessed when the quality of life (QOL) in thyroid cancer patients is investigated. The aim of this study was to measure the QOL difference in thyroid cancer survivors with and without HPT.

METHODS

Participants for this analysis were enrolled in 13 countries from a study that pilot-tested a thyroid cancer-specific QOL instrument. They were included if they had been diagnosed with thyroid cancer at least 9 months previously. QOL was measured using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core (EORTC QLQ-C30) and some items on HPT symptoms (eg, tingling in fingers or toes). HPT status and other clinical data were extracted from the patients' medical charts. Comparisons of QOL domains between patients with and without HPT were performed using Mann-Whitney U test. The occurrence of HPT-related symptoms was compared using chi-square tests. Multiple ordinal regression analysis was performed to evaluate factors that might affect QOL.

RESULTS

Eighty-nine patients participated in this study, 17 of whom were considered to have HPT. Patients in the HPT group reported significantly reduced QOL in 9 of the 15 scales of the EORTC QLQ-C30 compared to patients without HPT. Regression analysis showed that HPT was independently negatively associated with various scales of the QLQ-C30. Both groups showed a high prevalence of typical HPT symptoms.

CONCLUSION

Thyroid cancer patients with HPT report significantly impaired QOL compared to thyroid cancer survivors without HPT. The assessment of HPT should be considered when measuring QOL in thyroid cancer patients.

Obtaining Patient-Reported Outcomes Electronically With "OncoFunction" in Head and Neck Cancer Patients During Aftercare

The disease and treatment of patients with head and neck cancer can lead to multiple late and long-term sequelae. Especially pain, psychosocial problems, and voice issues can have a high impact on patients' health-related quality of life. The aim was to show the feasibility of implementing an electronic Patient-Reported Outcome Measure (PROM) in patients with head and neck cancer (HNC). Driven by our department's intention to assess Patient-Reported Outcomes (PRO) based on the International Classification of Functioning during tumor aftercare, the program "OncoFunction" has been implemented and continuously refined in everyday practice. The new version of "OncoFunction" was evaluated by 20 head and neck surgeons and radiation oncologists in an interview. From 7/2013 until 7/2017, 846 patients completed the PROM during 2,833 of 3,610 total visits (78.5%). The latest software version implemented newly developed add-ins and increased the already high approval ratings in the evaluation as the number of errors and the time required decreased (6 vs. 0 errors, 1.35 vs. 0.95 min; p<0.01). Notably, patients had different requests using PRO in homecare use. An additional examination shows that only 59% of HNC patients use the world wide web. Using OncoFunction for online-recording and interpretation of PROM improved data acquisition in daily HNC patients' follow-up. An accessory timeline grants access to former consultations and their visualization supported and simplified structured examinations. This provides an easy-to-use representation of the patient's functional outcome supporting comprehensive aftercare, considering all aspects of the patient's life.

Associations of cardiovascular risk factors and retinal vessel dimensions at present and their evolution over time in a healthy working population

PURPOSE

The aim of this study was to investigate whether an association between retinal vessel diameters with blood pressure and other risk factors exists in a healthy working population and whether current risk factors can be used as predictors for retinal vessel changes over time.

METHODS

Retinal photographs and medical data were obtained during a voluntary work health check in 2010 and 2013. The central retinal arterial equivalent (CRAE) and central retinal venular equivalent (CRVE) were assessed using a semi-automated software. Linear regression analysis was carried out to determine associations with systemic parameters and cardiovascular risk factors.

RESULTS

A total of 1685 participants had gradable photographs and full medical data with a mean age of 44.8 years (SD: 10.2) and 80.8% being male; full data were obtained in both 2010 and 2013 for 365 participants allowing for longitudinal analysis. In the cross-sectional analysis, a mean CRAE of 171.2 ±18.3 μm and a mean CRVE 215.8 ± 18.6 μm were found. A significant negative association for CRAE was seen for age, mean arterial blood pressure (MABP), body mass index (BMI) and high-density lipoprotein (HDL), while triglycerides, spherical equivalent (SAE) and being a current smoker were positively associated. For CRVE age, MABP, HbA1c and HDL were negatively associated, while being female, low-density lipoprotein, white blood cell count, SAE and being a current smoker showed a positive association. The linear regression model for the cross-sectional analysis explained 31% and 21% of the variance of CRAE and CRVE, respectively. The longitudinal analysis showed a mean decrease of -1.6 μm (p = 0.04) for CRAE and -2.0 (p = 0.005) for CRVE within the three-year time frame. Linear regression analysis with longitudinal data showed a significant association for HDL and CRAE, while for other factors no statistically significant association between current risk factors and changes in CRAE and CRVE was observed.

CONCLUSION

The width of both arterial and venous retinal vessels shows associations not only with arterial blood pressure but also with biochemical markers of cardiovascular risk. While such effects are partially established for elderly persons, our study results indicate that they apply also in a young population in working age with seemingly unimpaired health.

Quality of life of patients more than 1 year after surgery for thyroid cancer

PURPOSE

Patients with thyroid cancer are often assumed to have no quality of life (QOL) impairments after treatment because of thyroid cancer's good prognosis. However, the QOL implications of surgical complications and the necessity to take lifelong medication are seldom assessed.

METHODS

Patients who had surgery due to thyroid cancer at the University Medical Center Mainz between 2010 and 2015 and who had calcium or parathyroid hormone levels below the reference values immediately following surgery were eligible for this study. QOL was assessed using the EORTC QLQ-C30 and the thyroid cancer module EORTC QLQ-THY34. Multiple logistic regression was used to determine factors associated with a worse QOL compared with a general population.

RESULTS

A total of 75 (56%) of 134 eligible patients participated in the study. Patients with persistent/prolonged calcium or vitamin D intake reported worse QOL in the domains of global health, physical functioning, role functioning, emotional functioning, and insomnia than patients without current intake. Current calcium and vitamin D intake, higher education, living with a partner, and age had an effect on the odds of having worse QOL than the age- and sex-adjusted general population.

CONCLUSION

Prolonged calcium and/or vitamin D intake are negatively associated with certain domains of QOL in thyroid cancer patients who are at least 1 year post surgery. Assessment of calcium and vitamin D and diagnosis of hypoparathyroidism are therefore important for the follow-up of thyroid cancer survivors since it may affect their QOL.

Quality of life in patients with hypoparathyroidism receiving standard treatment: a systematic review

PURPOSE

Hypoparathyroidism is a rare endocrine disorder for which replacement therapy of the missing parathyroid hormone is not the standard therapeutic option. Current standard treatment consists of calcium and vitamin D supplementation. The intake of calcium and vitamin D supplementation can lead to complications and therefore might negatively influence patients' quality of life.

METHODS

A systematic literature review was performed to assess the current knowledge on the influence of hypoparathyroidism on patients' quality of life. The literature search was conducted in PubMed and Web of Science; all relevant literature published by August 24, 2016, was included.

RESULTS

In total 372 records were found. After title and abstract screening, 14 studies remained for a full-text screening. The full-text screening resulted in five studies which were included into the systematic review. Comparing the results with a norm-based reference population, three studies reported lower SF-36 scores for hypoparathyroidism patients. Two studies showed a reduced quality of life in hypoparathyroidism patients when their results were compared to control populations.

CONCLUSION

Most hypoparathyroidism patients receiving standard treatment show stable calcium and vitamin D levels. However, hypoparathyroidism patients still report reduced quality of life and experience physical, mental, and emotional symptoms. Therefore, it is assumed that the lack of parathyroid hormone directly influences the patients' quality of life. This review indicates that patients with hypoparathyroidism have a reduced quality of life in comparison to norm-based populations or matched controls. Further studies are required to quantify the effect of hypoparathyroidism on patients' quality of life using disease-specific questionnaires and controlling for the co-morbidities and etiologies of the patients.

Influenza A Viruses Detected in Swine in Southern Germany after the H1N1 Pandemic in 2009

Infections with influenza A viruses (IAV) are highly prevalent in swine populations, and stable cocirculation of at least three lineages has been well documented in European swine - till 2009. However, since the emergence of the human pandemic pdmH1N1 virus in 2009, which has been (re)introduced into individual swine herds worldwide, the situation has been changing. These variations in the respective IAV pools within pig populations are of major interest, and the zoonotic potential of putative emerging viruses needs to be evaluated. As data on recent IAV in swine from southern Germany were relatively sparse, the purpose of this study was to determine the major IAV subtypes actually present in this region. To this aim, from 2010 to 2013, 1417 nasal swabs or lung tissue samples from pigs with respiratory disease were screened for IAV genomes. Overall, in 130 holdings IAV genomes were detected by real-time RT-PCR targeting the matrix protein gene. For further analyses, several PCR protocols were adapted to quickly subtype between H1, pdmH1, H3, N1 and N2 sequences. Taken together, cocirculation of the three stable European lineages of IAV was confirmed for Bavaria. H1N1 sequences were identified in 59, whereas H1N2 genomes were only diagnosed in 14, and H3N2 in 9 of the holdings analysed. However, pdmH1 in combination with N1 was detected in 2010, 2012 and 2013 confirming a presence, albeit in low prevalence, likewise pdmH1N2 reassortant viruses. Interestingly, individual cases of coinfections with more than one subtype were diagnosed. Partial genome sequences were determined and phylogenetic analyses performed. Clearly other than in the human population classically circulating IAV have not been displaced by pdmH1N1 in Bavarian swine. However, some interesting viruses were detected. Further surveillance of these viruses in the Bavarian pig population will be of major importance, to monitor future developments.

The Region of Difference Four is a Robust Genetic Marker for Subtyping Mycobacterium caprae Isolates and is Linked to Spatial Distribution of Three Subtypes

Alpine Mycobacterium caprae isolates found in cattle and red deer display at least three genetic variations in the region of difference four (RD4) that can be used for further differentiation of the isolates into the subtypes 'Allgäu', 'Karwendel' and 'Lechtal'. Each genomic subtype is thereby characterized by a specific nucleotide deletion pattern in the 12.7-kb RD4 region. Even though M. caprae infections are frequently documented in cattle and red deer, little is known about the transmission routes. Hence, robust markers for M. caprae subtyping are needed to gain insight into the molecular epidemiology. For this reason, a rapid and robust multiplex PCR was developed for the simultaneous detection of three M. caprae RD4 subtypes and was used to subtype a total number of 241 M. caprae isolates from animals (145 cattle, 95 red deer and one fox) from Bavaria and Austria. All three subtypes occur spatially distributed and are found in cattle and in red deer suggesting transmission between the two species. As subtypes are genetically stable in both species it is hypothesized that the described genetic variations developed within the host due to 'within-host replication'. The results of this study recommend the genomic RD4 region as a reliable diagnostic marker for M. caprae subtype differentiation.

ARFI-based tissue elasticity quantification and kidney graft dysfunction: first clinical experiences

BACKGROUND AND PURPOSE

Beyond the medical history, the clinical exam and lab findings, non-invasive ultrasound parameters such as kidney size and Doppler values (e.g. the resistive index) are important tools assisting clinical decision making in the monitoring of renal allografts. The gold standard for the diagnosis of renal allograft dysfunction remains the renal biopsy; while an invasive procedure, the justifiable necessity for this derives from its definitive nature a requirement beyond the synopses of all non-invasive tools. "Acoustic Radiation Force Impulse Imaging"(ARFI)-quantification is a novel ultrasound-based technology measuring tissue elasticity properties. So far experience related to this new method has not been reported in renal transplant follow-up. The purpose of this study was to evaluate changes in ARFI-measurements between clinically stable renal allografts and biopsy-proven transplant dysfunction.

METHODS

We employed "Virtual Touch™ tissue quantification" (Siemens Acuson, S2000) for the quantitative measurement of tissue stiffness in the cortex of transplant kidneys. We performed initial baseline and later disease-evaluative ultrasound examinations in 8 renal transplant patients in a prospective study design. Patients were first examined during stable allograft function with a routine post-transplant renal ultrasound protocol. A second follow-up examination was carried out on subsequent presentation with transplant dysfunction prior to allograft biopsy and histological evaluation. All patiens were examined using ARFI-quantification (15 measurements/kidney). Resistive indices (RI) were calculated using pulsed-wave Doppler ultrasound, and transplant kidney size was measured on B-mode ultrasound images. All biopsies were evaluated histologically by a reference nephropathologist unaware of the results of the ultrasound studies. Histopathological diagnoses were based on biopsy results, taking clinical and laboratory findings into account. Finally we calculated the relative changes in ARFI-quantification, resistive indices and the absolute change of kidney size on a percentage basis at these defined assessment times and compared the results with the final pathologic diagnosis.

RESULTS

Histological results enumerated five cases of acute T-cell-mediated rejection, one case of calcineurin inhibitor toxicity and two cases of acute tubular necrosis. Calcineurin inhibitor toxicity and acute tubular necrosis were subsumed as "other pathologies". Mean ARFI-values showed an average increase of more than 15% percent in transplants with histologically proven acute rejection whereas no increase was seen in transplants with other pathologies. Mean RI-values showed no increase either in the diagnostic group of acute rejection, nor in the group with other pathologies. Kidney size showed a mean absolute increase of 0.5 centimetres in allografts with acute rejection, whereas a mean decrease of 0.17 centimetres was seen in the group with other pathologies.

CONCLUSION

As shown before in other studies, RI values and kidney size are of doubtful utility in the evaluation of kidney allograft dysfunction. ARFI-based elasticity measurement shows promise as a complementary non-invasive parameter in follow-on diagnosis of renal allograft rejection.

Radiochemotherapy induces a favourable tumour infiltrating inflammatory cell profile in head and neck cancer

Head and neck squamous cell cancers (HNSSC) generate an immune-suppressive micro-environment by a specific pattern of tumour infiltrating inflammatory cells. The aim of our study was to evaluate the impact of radiochemotherapy on the numbers and composition of inflammatory cells and its influence on outcome. Fifty-eight patients suffering from oral cavity cancer were studied, whose therapy consisted of concurrent radiochemotherapy followed by surgery. Numbers and ratios of tumour infiltrating inflammatory cells were compared prior to and after radiochemotherapy. Intraepithelial and stromal location of tumour infiltrating inflammatory cells was analysed separately. Infiltration of CD3(+), CD4(+), CD25(+), FoxP3(+), CD8(+), Granzyme B(+), CD20(+) and CD68(+) cells predominated in the peritumoural stromal compartment, whereas CD1a(+) dendritic cells were found more frequently in the intraepithelial compartment. Neoadjuvant treatment was associated with a general decrease of tumour infiltrating inflammatory cells in both compartments. The CD8(+) and Granzyme B(+) cytotoxic cells decreased only slightly after RCT. In contrast, the decrease of FoxP3(+) regulatory T cells was more pronounced and the cytotoxic T-cell/FoxP3(+) ratio increased 2- to 3-fold in both compartments, respectively. Patients with high cytotoxic cell numbers, high dendritic cell numbers and a high ratio of cytotoxic cells to regulatory T cells had a better disease free survival. Concurrent radiochemotherapy of oral squamous cell carcinoma was shown to drive the composition of inflammatory cells in a direction which is supposed to be prognostically favourable.

83 EFFECTS OF HUMAN INTERFERON-α ON GENE EXPRESSION IN THE BOVINE ENDOMETRIUM IN COMPARISON TO DAYS 15 AND 18 OF PREGNANCY

Interferon-τ (IFNT), a Type-I interferon (IFN), is the pregnancy recognition signal produced by the ruminant conceptus (Godkin et al. 1984; Hansen et al. 1985; Helmer et al. 1987; Spencer et al. 2007). In addition to these specific functions of IFNT in ruminants, many studies suggest that IFNs play a general role in establishment of pregnancy and conceptus attachment/implantation in most mammalian species (Bazer et al. 2009; Bazer et al. 2010; Johnson et al. 2009; Roberts et al. 2008). To characterise the effects of prototype Type-I IFNs on bovine endometrium, in experiment one, Simmental heifers were treated from Day 14 to Day 16 of the oestrous cycle with a rod-shaped intrauterine device releasing human interferon-α (IFNA) or placebo lipid extrudates or PBS only as controls (n = 4 each). Lipid formulation and concentration of human IFNA were adjusted to release 8–9 × 107 IU of IFNA over a period of 2 days in in vitro release experiments. On Day 16, endometrial biopsy samples were collected after flushing the uterus. In experiment 2, endometrial tissue samples were obtained on Day 12, 15 and 18 post-mating from nonpregnant or pregnant heifers. All samples from both experiments were analysed with an Affymetrix Bovine Genome Array (Santa Clara, CA). In experiment one, IFNA treatment resulted in differential gene expression in the bovine endometrium. Significant differences were found between the IFNA group and both control groups, whereas no differences were observed between the placebo and the PBS control group. In experiment 2, differentially expressed genes were found between pregnant and nonpregnant endometria on Day 15 and 18, but not on Day 12, with many of them known IFN-stimulated genes. The comparison of the data sets from both experiments showed very similar gene expression changes for most of the typical IFN-stimulated genes. In addition, several genes were identified which were differentially expressed after IFNA treatment but not different at Day 15 or 18 of pregnancy compared with nonpregnant animals. Conversely, some genes were found as differentially expressed during pregnancy but not after IFNA treatment. Differential expression of selected genes was verified by quantitative real-time PCR and 4 genes, namely jumonji C domain containing histone demethylase 1 homologue D (JHDM1D), indoleamine 2,3-dioxygenase 1 (IDO1), fatty acid binding protein 3, muscle and heart (mammary-derived growth inhibitor) (FABP3) and dickkopf homologue 1 (DKK1), were selected for localization of mRNA expression in endometrial tissue sections. The findings of this study suggest that there may be differential effects of bovine IFNT compared with human IFNA and that some pregnancy-specific changes in the endometrium are elicited by conceptus-derived factors other than IFNT. This study was supported by the German Ministry for Education and Research (BMBF, FUGATO-plus, COMPENDIUM) and the German Research Foundation (DFG FOR478). The authors are part of the European Union COST action GEMINI.

[Evaluation of a renal biopsy: what information is important for nephrologists?]

A kidney biopsy is an important and frequently used diagnostic tool in routine nephrology. In order to obtain relevant clinical information from a renal biopsy close cooperation between clinicians and pathologists is mandatory. The better the information obtained from nephrologists and the better the understanding by nephrologists and the quality of the kidney biopsy, the more rewarding is the information from pathologists. The following paper will discuss some practical aspects regarding the interaction between nephrology and pathology which may not be known or poorly handled and may thus cause misunderstanding. In order to facilitate interaction between clinicians and pathologists some guidelines concerning the procedure and work-up of routine kidney biopsies have been established and will be discussed in detail.

ARFI-based tissue elasticity quantification in comparison to histology for the diagnosis of renal transplant fibrosis

BACKGROUND AND PURPOSE

Until recently clinical diagnosis of chronic renal allograft dysfunction could only be established invasively by renal biopsy. Given the risks of that procedure, a non-invasive, diagnostic test would be very advantageous. Novel ultrasound-based elasticity tools, using "Acoustic Radiation Force Impulse (ARFI)" technology are now available. Previously this technique has been utilised to quantify liver fibrosis. First results of these studies are promising. The purpose of our study was to investigate correlation between stiffness values obtained by ARFI-quantification and histological fibrosis score in renal transplants.

METHODS

We employed "Virtual Touch™ tissue quantification" (Siemens Acuson, S2000) to quantitatively measure tissue stiffness in the cortex of transplant kidneys. Eighteen patients were included in this prospective study, recording close temporal ARFI-quantification and fibrosis measurements. All patients undergoing renal transplant biopsy were examined with ARFI-quantification (15 measurements per transplant kidney). Resistive indices were also calculated from pulsed-wave Doppler ultrasound. Transplant biopsies were histologically evaluated by a reference nephropathologist and graded according to the percentage of fibrosis and to the BANFF-score. Due to the non-normal distribution of the data the Spearman-correlation-coefficient (rho) was used to assess the bivariate relationship of ARFI and fibrosis in the transplant kidney.

RESULTS

There was a significant positive moderate correlation between mean ARFI-values and the grade of fibrosis (rho = +0.465; p = 0.026). This correlation was also valid for the mean ARFI-values and the BANFF-category (rho = +0.468; p = 0.025). There was no significant correlation between the mean ARFI-values and the resistive indices in the transplant kidney (rho = +0.034; p = 0.904). Nevertheless, a positive correlation between the mean RI-values of the kidney and the grade of fibrosis was established (rho = +0.563; p = 0.015).

CONCLUSION

The mean values of ARFI measurements and the resistive indices are potentially independent explanation variables for evaluating the grade of fibrosis in transplant kidneys.

The Arabidopsis sugar transporter (AtSTP) family: an update

The Arabidopsis sugar transporter (AtSTP) family is one of the best characterised families within the monosaccharide transporter (MST)-like genes. However, several aspects are still poorly investigated or not yet addressed experimentally, such as post-translational modifications and other factors affecting transport activity. This mini-review summarises recent advances in the AtSTP family as well as objectives for future studies.

Avian influenza A virus monitoring in wild birds in Bavaria: occurrence and heterogeneity of H5 and N1 encoding genes

To define avian influenza virus prevalence in wild birds in Bavaria, 12,930 tracheal, cloacal swabs or tissue samples from various waterfowl species were screened between January 2006 and December 2007. In 291 (2.3%) birds, genomes of influenza A viruses were detected by reverse transcription real-time PCR (rRT-PCR) targeting the matrix protein genes. Furthermore, solitary H5 hemagglutinin or N1 neuraminidase encoding genes were identified in 35 (0.3%) apparently healthy birds; whereas highly pathogenic (HPAI) H5N1 virus genomes were only diagnosed in dead wild birds (n = 93; 0.7%) found across this federal state region. In this study, multiple import events for H5N1 viruses were confirmed during 2006 and 2007. In addition, our findings argue against an existing HPAI H5N1 reservoir in aquatic birds in Bavaria. By contrast, phylogenetic analyses of the H5 or N1 sequences of low pathogenic avian influenza (LPAI) viruses revealed a marked diversity and multiple genetic lineages. This diversity of LPAI H5 and N1 subtype components indicates the existence of LPAI HA and NA gene pools which differ from the Bavarian HPAI H5N1. Moreover, the hemagglutinin amino acid differences between LPAI H5 viruses of a western European genotypic lineage observed in wild birds suggest a continuous evolution of LPAI viruses in Bavaria.

Generation of avian influenza virus (AIV) contaminated fecal fine particulate matter (PM(2.5)): genome and infectivity detection and calculation of immission

As a model for aerosol transmission, chicken feces was spiked with avian influenza virus (AIV) subtype H10N7 and used to generate a fine particulate matter aerosol. For this an innovative aerosol chamber was developed, that collected PM(2.5) on quartz microfiber filters. With AIV contaminated PM(2.5) dust-coated filters different incubation times ranging from 0 to 4 days and storage mainly at +4 and +20 degrees C and at different relative humidity (RH) were performed. Embryonic death in inoculated hen's eggs with filter elute was the AIV infectivity read out. To determine viral genome presence quantitative real time RT-PCR was applied. The filter elutes contained AIV genome as well as viable virus whereby +20 degrees C indicated a borderline temperature for infectious virus stability. In addition, high relative humidity was critical for AIV viability in PM(2.5). The results allowed a dispersion calculation of infectious AIV in aerosols assuming a worst case scenario for an AIV outbreak in poultry farms. Thus exposure to AIV associated with PM(2.5) is possible near to infected farms and may be a serious risk for fatal influenza disease in both man and animals. Airborne transmission should be effectively preventable by dispersion of water combined with disinfection into the inside air as well as the exhaust air stream of AIV infected farms.

Gold cluster formation on a fullerene surface

The growth of Au clusters on a fullerene thin film was investigated by in situ photoelectron spectroscopy in the ultraviolet (UPS) and x-ray (XPS) regime. Due to its highly corrugated surface fullerene films provide a wide range of bonding sites which could be exploited as molecular templates and serve to create a cluster superstructure. To gain insight into the fullerene-Au interaction two types of experiments were performed: (i) the deposition of Au on a fullerene surface, and (ii) the deposition of fullerenes on a Au surface. In both experiments an island growth mode is observed. The deposition of submonolayer amounts of C60 onto a gold film showed that the main interaction of the two species is due to chemisorption of the first C60 monolayer. In addition a constant band bending in the fullerene film is detected, but the UPS valence-band spectra show that there is no charge transfer from the Au to the C60 lowest unoccupied molecular orbital. In the reverse experiment, the cluster growth of Au on the corrugated C60 surface, the analysis of the Au core level does not reveal a specific bonding or nucleation site for Au atoms and clusters. This is in contrast to observations with Si clusters, which prefer to reside in the troughs between the fullerene molecules. The Au clusters grow continually from a size of about 55 atoms for the early stages of growth up to 150 atoms for the deposition of a nominal coverage of 1.5 nm. These data are derived from an analysis of the d-band splitting and the Au 4f core-level shift due to delayed photohole relaxation. The thermal stability of the Au-clusters-covered fullerene film was investigated by annealing in situ up to temperatures of 650 degrees C. For temperatures up to 450 degrees C a continuous growth of the clusters is detected, which is accompanied by a slight drop in Au concentration in the range of XPS for annealing temperatures higher than 350 degrees C. This may be due to a ripening of the clusters. The presence of Au apparently delays fullerene sublimation. The film shows a very good thermal stability and even after annealing at 650 degrees C there is still a fullerene film detectable in the photoelectron spectroscopy spectra.