The effects of force application on the compressive properties of femoral spongious bone.

BACKGROUND: End artefacts play a major role in uniaxial compression tests with cancellous bone specimens. They lead to misinterpretation of mechanical parameters of bones due to uncontrolled introduction of bending moments into the free ends of trabeculae. This work aims to simplify current methods preventing end-artefacts and furthermore to investigate the influence of end artefacts on plateau stress. METHODS: 176 cylindrical cancellous bone specimens were taken from human femoral condyles and tested in uniaxial compression. The specimens were divided into 2 groups (direct, end-cap) and compressive modulus, maximum stress, plateau stress, energy absorbtion as well as apparent density were evaluated. Density values are from separate specimens which are immediately adjacent to the mechanical specimen. FINDINGS: All mechanical parameters were significantly higher in the end-cap specimens than in the direct ones by about 30 - 40 %, thus reaching similar differences as the previous studies. Greatest differences between groups were determined for compressive modulus (45 %) and plateau stress (35 %). Energy absorbtion can be explained with great accuracy by plateau stress (P < 0.001; R2 = 0.95). Among all parameters plateau stress can be best explained by apparent density using an exponential function (P < 0.001; R2 = 0.38). INTERPRETATION: The end-cap method used here to prevent end artefacts showed variations consistent with the literature when compared to the direct method. Additionally it was shown that the way in which the force is applied to the specimen has a major influence on the failure progression behavior, which was characterized using the plateau stress.

Biomechanical validation of additively manufactured artificial femoral bones.

Replicating the mechanical behavior of human bones, especially cancellous bone tissue, is challenging. Typically, conventional bone models primarily consist of polyurethane foam surrounded by a solid shell. Although nearly isotropic foam components have mechanical properties similar to cancellous bone, they do not represent the anisotropy and inhomogeneity of bone architecture. To consider the architecture of bone, models were developed whose core was additively manufactured based on CT data. This core was subsequently coated with glass fiber composite. Specimens consisting of a gyroid-structure were fabricated using fused filament fabrication (FFF) techniques from different materials and various filler levels. Subsequent compression tests showed good accordance between the mechanical behavior of the printed specimens and human bone. The unidirectional fiberglass composite showed higher strength and stiffness than human cortical bone in 3-point bending tests, with comparable material behaviors being observed. During biomechanical investigation of the entire assembly, femoral prosthetic stems were inserted into both artificial and human bones under controlled conditions, while recording occurring forces and strains. All of the artificial prototypes, made of different materials, showed analogous behavior to human bone. In conclusion, it was shown that low-cost FFF technique can be used to generate valid bone models and selectively modify their properties by changing the infill.

Punzi-loss:: a non-differentiable metric approximation for sensitivity optimisation in the search for new particles.

We present the novel implementation of a non-differentiable metric approximation and a corresponding loss-scheduling aimed at the search for new particles of unknown mass in high energy physics experiments. We call the loss-scheduling, based on the minimisation of a figure-of-merit related function typical of particle physics, a Punzi-loss function, and the neural network that utilises this loss function a Punzi-net. We show that the Punzi-net outperforms standard multivariate analysis techniques and generalises well to mass hypotheses for which it was not trained. This is achieved by training a single classifier that provides a coherent and optimal classification of all signal hypotheses over the whole search space. Our result constitutes a complementary approach to fully differentiable analyses in particle physics. We implemented this work using PyTorch and provide users full access to a public repository containing all the codes and a training example.

Influence of osteoporosis on the compressive properties of femoral cancellous bone and its dependence on various density parameters.

Data collection of mechanical parameters from compressive tests play a fundamental role in FE modelling of bone tissues or the developing and designing of bone implants, especially referring to osteoporosis or other forms of bone loss. A total of 43 cylindrical samples (Ø8 × 16 mm) were taken from 43 freshly frozen proximal femora using a tenon cutter. All femora underwent BMD measurement and additionally apparent- and relative- and bulk density (ρapp, ρr, ρb) were determined using samples bordering the compressive specimen on the proximal and distal regions. All samples were classified as "normal", "osteopenia" and "osteoporosis" based on the DEXA measurements. Distal apparent density was most suitable for predicting bone strength and BMD. One novel aspect is the examination of the plateau stress as it describes the stress at which the failure of spongious bone progresses. No significant differences in mechanical properties (compressive modulus E; compressive stress σmax and plateau stress σp) were found between osteopenic and osteoporotic bone. The results suggest that already in the case of a known osteopenia, actions should be taken as they are applied in the case of osteoporosis A review of the literature regarding extraction and testing methods illustrates the urgent need for standardized biomechanical compressive material testing.

[Medical child protection during the coronavirus lockdown]. / Medizinischer Kinderschutz während des Corona-Lockdowns: Vergleichende Befunde der Kinderschutzfälle aus Kliniken und Ambulanzen in Deutschland.

BACKGROUND: There are indications that during the lockdown and the measures of social distancing due to the coronavirus disease 2019 (COVID-19) pandemic, physical and sexual child abuse and neglect may have increased. Additionally, decreased social control may have led to a lower detection rate of child protection cases. OBJECTIVE: This study aimed to better understand the impact of the lockdown in Germany on the frequency and severity of child abuse and neglect. To do so the quantity and quality of cases of suspected child abuse and neglect in German pediatric departments and outpatient departments for medical child protection were examined. METHODS: In May 2020 a total of 343 institutions of medical child protection were invited to fill in a questionnaire with items describing their institution and items depicting cases of child protection in March and April 2019 and 2020 regarding age, form and severity of abuse as well as items to describe particular remarks and ideas for child protection during the pandemic. RESULTS: Out of the 343 pediatric departments and outpatient departments of medical child protection invited, the participation rate was 46%. In this study 81 institutions reported the total cases of suspected child abuse or neglect for both March and April 2019 and 2020. The number of cases dropped from 454 to 387 (-15%) in outpatient child abuse clinics and from 307 to 246 (-20%) in pediatric inpatient departments. Regarding the age of affected children and the form of abuse no significant differences were found. CONCLUSION: The study found a decrease in reported cases of suspected child abuse and neglect during the lockdown in March and April 2020 compared to 2019. While the results do not show an increase of total child abuse and neglect, as suspected by many professionals, the decrease in reported cases may be explained by a steep increase in unreported cases due to reduced social control.

Correction to: Translation and cross-cultural adaptation of eight pediatric PROMIS® item banks into Spanish and German.

In the original publication of the article, two of the author names "L. A. Schröder, F. Metzner" and email address of the authors "J. Devine, J. Moon, A. C. Haller" were missed out. The correct author group with affiliations are provided in this correction.

Translation and cross-cultural adaptation of eight pediatric PROMIS® item banks into Spanish and German.

PURPOSE: The Patient-Reported Outcome Measurement Information System (PROMIS®) is a National Institutes of Health (NIH)-funded initiative to develop reliable, valid, and normed item banks to measure health. We describe the first large-scale translation and cross-cultural adaptation effort to German and Spanish of eight pediatric PROMIS item banks: Physical activity (PAC), subjective well-being (SWB), experiences of stress (EOS), and family relations (FAM). METHODS: We utilized methods outlined in the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) PRO Translation Task Force recommendations. Ten professional translators performed a translatability assessment and generated forward translations. Forward Translations were compared within a country and cross-culturally to identify problems and to produce a consensus-derived version, which was then back translated, evaluated, and revised where necessary. Reconciled versions were evaluated in cognitive interviews with 126 children before finalization. RESULTS: Eight resulting pediatric PROMIS® item banks were translated: Two PAC banks (22 total items), three SWB banks (125 total items), two EOS banks (45 total items), and one FAM bank (47 total items). Up to 92% of all items raised no or only minor translation difficulties, 0-5.6% were difficult to translate. Up to 20% item revisions were necessary to ensure conceptual equivalence and comprehensibility. Cognitive interviews indicated that 91-94% of the final items were appropriate for children (8-17 years). CONCLUSIONS: German and Spanish translations of eight PROMIS Pediatric item banks were created for clinical trials and routine pediatric health care. Initial translatability assessment and rigorous translation methodology helped to ensure conceptual equivalence and comprehensibility. Next steps include cross-cultural validation and adaptation studies.

Patients with Postpartum Depression in Gynaecological Practices in Germany - Results of a Representative Survey of Local Gynaecologists about Diagnosis and Management.

THEORETICAL BACKGROUND AND CURRENT ISSUES: For the sake of pre-emptive child protection it is necessary to recognise signs of postpartum depression (PPD) in pregnant women and young mothers as early as possible and to initiate adequate assistance. Because of their high acceptance, especially in the phases of pregnancy and birth, the local gynaecologists offer ideal prerequisites for access to the parents. This study evaluates the current status of diagnosis and management of PPD in gynaecological practices. MATERIAL AND METHODS: In a representative German nation-wide questionnaire survey taking the regional distribution into account n = 3000 local gynaecologists were selected at random and contacted by post. The questionnaire addressed their approaches to the diagnosis and management of PPD as well as the encountered barriers. RESULTS: Among the n = 1034 participating gynaecologists (response rate: 35 %) half of them dealt actively with PPD; 16 % used a questionnaire for this purpose. Consultation by the gynaecologist (84 %) or referral to therapists or hospitals (86 %) were among the most common interventions in the management of PPD. A need for improvement in the management of women with PPD was recognised equally often. As barriers the gynaecologists mentioned above all the lack of time, the low reimbursements for consultations and the lack of effective treatment options. Predictors for an active anamnesis were found to be female gender of the gynaecologist, possession of an additional psychosomatic qualification and practice located in an urban catchment area or state of the former West Germany. CONCLUSION: The results clearly demonstrate a high acceptance for the management of PPD by gynaecologists as well as the need for further action to improve the care of patients with PPD in gynaecological practices.

[Importance and Implementation of Prevention in Germany--A Nationwide Survey of Decision-makers in the GKV-Spitzenverband and Political Decision-makers]. / Stellenwert und Umsetzung der Prävention in Deutschland--Eine bundesweite Befragung von Entscheidungsträgern in GKV-Spitzenverband, Bund, Ländern und Kommunen.

Representatives of the statutory health insurance (n=46) and policy makers at the local, federal and state level (n=136) were interviewed in 2 nationwide online surveys about the significance and degree of implementation of prevention. The group comparison between the decision-makers shows significant differences in terms of attitudes towards health prevention. The political leaders are demanding an improvement of the GKV-benefit package and the obstacles require the cooperation of urgent attention.

[Families with Migrant Backgrounds as Target Group of Early Interventions: Results of a Social Early Warning System in a Metropolitan Region]. / Familien mit Migrationshintergrund als Zielgruppe in den Frühen Hilfen: Ergebnisse eines Sozialen Frühwarnsystems einer Metropolregion.

OBJECTIVES: Families with migrant backgrounds (MB) are exposed to several psychosocial risk factors that increase the likelihood of impaired child development, in particular. QUESTIONS: We investigated whether families with MB differ from families without MB regarding their psychosocial stressors in the period of pregnancy and birth. METHOD: As part of a social early warning system in an obstetrics clinic in Germany n=502 families with MB were compared with n=349 families without MB with respect to the degree of stress and stress factors on the basis of an initial screening of risk factors for child maltreatment by a midwife or physician and a subsequent structured clearing interview by social education workers during the mothers' inpatient hospitalisation. RESULTS: For families without MB, a significantly higher total score was found in the risk screening (M=3,9 points vs. M=2,9 points) in comparison to families with MB. While families with MB compared to families without MB were faced more frequently by social stressors, e. g., financial problems or a difficult housing situation (81 vs. 37%), they were less frequently impacted by mental strain (27 vs. 48%), young fathers (2 vs. 10%) and maternal psychiatric diseases (3 vs. 17%), according to the risk screening. Socio-economic determinants such as social inclusion and living environment were found to be important factors influencing the psychosocial stress level of families. CONCLUSION: Explanations and implications for research and practice are discussed.

[Health Promotion and Child Protection in the Paediatric Practice - Paediatricians as Protagonists in an Invitation and Reporting System for Child Health Check-ups]. / Prävention und Kinderschutz in der pädiatrischen Praxis - Kinderärzte als Akteure im Einladungs- und Meldewesen für Kinderfrüherkennungsuntersuchungen.

INTRODUCTION: Since 1971 routine child health check-ups allow the routine identification of dis-eases in children and adolescents. Paediatricians play a central role in health prevention in childhood and adolescence and are - on account of their acceptance and admission requirements - important actors in child protection. Thus, paediatric practitioners were actively involved in the invitation and reporting system for the routine child health check-ups (U6 and U7), which was introduced to increase participation rates and improve child protection in Hamburg. METHOD: By means of a questionnaire survey, all paediatric practitioners practicing in Hamburg were asked a year after introduction of the invitation and reporting system to report on their practical experience, and to share their assessment and criticism of the system (response rate 73%). RESULTS: Out of 110 participating pediatricians (M=19.5 years practical experience), 81% evaluated the invitation and reporting system as very useful, useful or rather useful; 83% supported an expansion of the system for routine child health check-ups, and about 18% observed an increased utilisation of routine child health check-ups especially from families with a migrant background and by socially-disadvantaged families. Criticism was made concerning ineffective procedures. CONCLUSION: The invitation and reporting system for routine child health check-ups in Hamburg shows how pediatricians can be integrated into the network of prevention and child welfare. It also shows their support of this system. Paying more systematic attention and an interdisciplinary network connecting paediatricians may contribute to a more comprehensive prevention and child protection.

[Status quo of children's preventative medicine programmes--results of the first German nationwide workshop 2011 in Frankfurt am Main]. / Zum aktuellen stand der kindervorsorgeprogramme--ergebnisse des ersten bundesweiten arbeitstreff ens 2011 in Frankfurt am Main.

10 of the 13 federal states presented their structures, implementation methods and results as part of the nationwide workshop for children's preventative medicine and early recognition projects for Germany on 9th September 2011 in Frankfurt am Main. This was the first time a full overview of all programmes of this kind in Germany has been possible. The programmes and data from these 10 presentations were analysed and compared. Despite the many differences between the legal frameworks and structural implementation, the programmes also displayed similarities in the implementation and in the problems which arise. Significantly improved participation rates for early recognition check-ups have been achieved in the context of the programmes. Previously, only a few detailed evaluations for the detection of risks to children's welfare and other effects such as vaccination rates and improvements in children's health through more advice and care were available.