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Bioburden of postmortem bone tissues with a procurement time exceeding 36 h
No full textTo qualify for bone donation many criteria must be met. For procurement, two time intervals—a postmortem interval (PMI) of 6 h (hours) until cooling of the deceased and a maximum procurement time of tissues within 24/36 h postmortem are mandatory. Expanding the procurement to donors with a longer PMI would be helpful e.g. to have more time to contact relatives for consent for donation. A loss of biomechanical quality of bone tissues should not be expected in the PMI until procurement, but the question of microbiological contamination remains. Therefore, samples from the iliac crest were procured under standard procurement conditions between 48 and 54 h (n = 14, group 1) and 72–78 h (n = 7, group 2) postmortem (pm). Samples were immediately frozen after procurement at < − 18 °C and sent to the German Institute for Tissue and Cell Replacement (DIZG) for mechanical preparation. Additionally, chloroform treatment was performed at the tissue bank of the Charité Berlin. After each step the samples were refrozen and sent to a contracted microbiological lab for bioburden testing according to the European Pharmacopoeia. Samples were tested after procurement, preparation, and chloroform treatment respectively. As acceptance criterion a maximum amount of 9 × 104 colony forming units per gram (CFU/g) tissue was defined. All samples were within the defined limit with a maximum value of 2.5 × 102 CFU/g. These values are in the range of bone tissues procured under non-strict-aseptic procurement conditions within 24 or 36 h and are within the capacity of the peracetic acid sterilization process used by several tissue banks
The Role and Development of Psychological Capital in the Context of Academia
No full textNull results, rejected articles, publication pressure or funding reductions—all of those are examples of challenging work conditions in academia. Coping with these adversities is crucial for wellbeing and success. Psychological Capital (PsyCap) positively affects performance and health outcomes in various work contexts. This study explores PsyCap and its components in academia. In Study 1, we examined academics’ PsyCap in relation to their in- and extra-role performance. Participants (n = 116) took part in an online survey with two measurement points. Results confirmed a positive link between PsyCap and performance dimensions. Looking at the components separately, self-efficacy was related to in-role performance and resilience to extra-role performance. Study 2 aimed at training PsyCap in a quasi-experimental setting with an experimental (n = 30), an active (n = 22), and a passive control group (n = 17) in a pretest–posttest design. Differences between the experimental and passive control groups were found with respect to overall PsyCap, but no differences between the experimental and active control group. Looking at specific components, besides self-efficacy and resilience (in line with their importance shown in Study 1), hope showed significant differences (experimental vs. passive control group). By taking this training approach, we revealed that the PsyCap intervention predicted an increase in self-efficacy, resilience, and hope and hereby detected valuable personal resource in academia. In conclusion, especially self-efficacy and resilience seem to play a crucial role for performance in academia. This provides valuable indications for personnel development measures for academics
On Consistently Assessing Alleged Mnemonic Systems (or, why isn’t Immune Memory “really” Memory?)
No full textA new species and the earliest occurrence of the Gnathosaurinae (Pterosauria) from the Late Kimmeridgian of Brunn, Germany
No full textThe so-called “Solnhofen limestones” of southern Germany are widely recognized for their abundance of Late Jurassic fossil vertebrates, with pterosaurs being no exception. Within the recognized plenitude of the pterosaurs within this assemblage, although ctenochasmatid remains are relatively abundant, gnathosaurines are scarce, with only one known Solnhofen representative of the group known thus far. The Late Kimmeridgian locality of Brunn (near Regensburg, Germany) represents the oldest locality of the Solnhofen complex (“Solnhofen Archipelago” in recent literature), with only one pterosaur having been described from this locality to date. Here, a second pterosaur taxon from within this locality and a new gnathosaur is introduced, Spathagnathus roeperi gen. et sp. nov., whose novel tooth and dental enamel features add to the known dental diversity for the group. The new taxon represents the oldest occurrence of a gnathosaurine and contributes to the paleoenvironmental stratigraphic range for the Gnathosaurinae within the overall fossil assemblage of the Solnhofen Archipelago. Furthermore, the new taxon adds to the known diversity of ctenochasmatids in the Late Jurassic and underlines the importance of this early radiation of pterodactyloid pterosaurs during this time
Improved quadriceps efficiency with a medial pivot in comparison to a cruciate‐retaining design in total knee arthroplasty
No full textPurpose:
The posterior cruciate-retaining (CR) design offers rotational freedom but risks abnormal kinematics and instability. The medial pivot (MP) design mimics native joint motion with a high-conformity medial and flat lateral interface. Within clinical studies, the MP design outclassed the CR design, but biomechanical studies are lacking. This study investigates the tibiofemoral and patellofemoral kinematics of both implant designs compared to native kinematics.
Methods:
Eight fresh-frozen cadaveric knee specimens underwent total knee arthroplasty using MP and CR designs. Testing was performed in a dynamic knee rig simulating active knee flexion (30–130°) under muscle load. Biomechanical assessments included tibial rotation, tibiofemoral translation, patellar tilt/shift, patellofemoral contact/pressure patterns and quadriceps force. Functional regressions were used to analyse the effects of the component designs on the native situation.
Results:
The MP design exhibited increased tibial rotation (130° flexion: MP 9.4° vs. CR 6.6°) and lateral anterior tibial translation during flexion (130° flexion: MP 25.8 mm vs. CR 22.6 mm). Both designs showed no significant differences in patellar tilt or shift and similar patellofemoral pressure (CR 3.2 MPa, MP 3.4 MPa) and contact patterns (CR 213.8 mm2 vs. MP 230.4 mm2). The MP design required lower quadriceps force, particularly in deep flexion (NS 452.6 N, CR 407.8 N and MP 367.3 N).
Conclusion:
The MP design provides a more native-like knee kinematic profile than the CR design, with a more pronounced MP motion pattern and reduced quadriceps loading
Personalized strategies for high-risk acute pulmonary embolism: addressing the “catastrophic” subgroup. Author’s reply
No full textComparing the proteome profiling of plasma-derived extracellular vesicles in individuals with schizophrenia and healthy controls: a pilot study
No full textBackground
Studying extracellular vesicles (EVs)—tiny intercellular communicators with a diverse molecular cargo—may provide insight into the poorly understood neuropathology and pathophysiology of schizophrenia (SCZ). Here, we focused on the protein profile of plasma-derived EVs with the aim to detect differences between individuals with SCZ and healthy controls (HCs).
Methods
EVs were isolated from blood plasma of 73 individuals with SCZ and 77 HCs and evaluated by nanoparticle tracking analysis, electron microscopy, and Western blot analysis. EV proteins were identified by liquid chromatography coupled with mass spectrometry. Proteomic data were analyzed using logistic regression analyses.
Results
A total of 1659 proteins were identified, and analyses were performed with the 1021 proteins with quantitative data available for more than 50 % of the participants in each group (SCZ and HC). Comparing these proteins between the two groups showed no significant differences. An enrichment analysis based on the proteins with a noncorrected significant p value revealed a significant enrichment of pathways connected to complement system. Although comparison of complement components between the two groups did not show significant differences, but it demonstrated that antipsychotics and duration of illness may affect EV protein levels.
Conclusion
Overall, even as our findings highlight the importance of medication use and duration of illness on EV protein levels, they suggest that the complement system may be involved in the etiopathology of SCZ. Although, the results of this pilot study need to be replicated in larger research, they may help elucidate the mechanisms involved in the pathophysiology of SCZ