Design and finite element modeling of two-dimensional nanomechanical biosensors for SARS-CoV-2 detection

SARS-CoV-2 is the causative agent of COVID-19 disease. The development of different variants has increased the prevalence, pathogenicity, and mortality of the SARS-CoV-2. Prompt diagnosis and timely initiation of therapy can undoubtedly minimize the damage caused by this virus. In this study, a wide range of emerging single layer two-dimensional materials (SL2DMs), including graphene, grapheme oxide (GO), reduced graphene oxide (rGO), hexagonal boron nitride (h-BN), Ti3C2Tx MXene, and MoS2that can be used to fabricate highly sensitive biosensors, are analyzed using the finite element method based on antigen-antibody interaction. Important design parameters including sensor size, sensor aspect ratio, number of viruses, and applying in-plane strain on sensor performance are analyzed using frequency shift technique. In the following, an analytical relationship that can predict the limit of detection (LOD) according to the above parameters is proposed. The results show that all the above materials have a good performance in detecting viruses in the sample range of 10-100 viruses. This range can be reduced significantly by applying strains of less than 0.1. Also, applying strain increases shift frequency index by 2 to 3 times, which is a significant result. The maximum and minimum sensor performance are obtained for GO and Ti3C2Tx, respectively. The results of this paper can be used to build a new generation of two-dimensional biosensors for rapid detection of COVID-19 and other viruses.

Two Novel Tri-Aryl Derivatives Attenuate the Invasion-Promoting Effects of Stromal Mesenchymal Stem Cells on Breast Cancer

Background:

The concept of Epithelial-Mesenchymal Transition (EMT) to promote carcinoma progression has been recognized as a venue for research on novel anticancer drugs. Triaryl template-based structures are one of the pivotal structural features found in a number of compounds with a wide variety of biological properties including anti-breast cancer. Among the various factors triggering EMT program, cyclooxygenase-2 (COX-2), NF-κB as well as the transforming growth factor-beta (TGF-β) have been widely investigated.

Objective:

Here, we aim to investigate the effect of two novel compounds A and B possessing triaryl structures, which interact with both COX-2 and TGF-β active sites and suppress NF-κB activation, on EMT in a co-culture system with breast cancer and stromal cells.

Methods:

MDA-MB-231 and bone-marrow mesenchymal stem (BM-MS) cells were co-cultured in a trans-well plate. Migration, matrigel-based invasion and colony formation in soft agar assays along with Real- time PCR and Western blot analysis were performed to examine the effect of compounds A and B on the invasive properties of MDA-MB-231 cells after 72 hours of co-culturing with BM-MSCs. In addition, TGF-beta interaction was investigated by Localized Surface Plasmon Resonance (LSPR).

Results:

BM-MSCs enhanced migration, invasion and anchorage-independent growth of the co-cultured MDAMB- 231 cells. A reduction in E-cadherin level concomitant with an increase in vimentin and N-cadherin levels following the co-culture implied EMT as the underlying process. Compounds A and B inhibited invasion and anchorage-independent growth of breast cancer cells co-cultured with BM-MSCs at 10µM. The observed inhibitory effects along with an increase in E-cadherin and a reduction in vimentin and ZEB2 levels suggest that the anti-invasive properties of compounds A and B might proceed through the blockade of stromal cell-induced EMT, mediated by their interaction with TGF-beta.

Conclusion:

These findings introduce compounds A and B as novel promising agents, which prevent EMT in invasive breast cancer cells.

Preferred Interpersonal Distances: A Global Comparison

Human spatial behavior has been the focus of hundreds of previous research studies. However, the conclusions and generalizability of previous studies on interpersonal distance preferences were limited by some important methodological and sampling issues. The objective of the present study was to compare preferred interpersonal distances across the world and to overcome the problems observed in previous studies. We present an extensive analysis of interpersonal distances over a large data set ( N = 8,943 participants from 42 countries). We attempted to relate the preferred social, personal, and intimate distances observed in each country to a set of individual characteristics of the participants, and some attributes of their cultures. Our study indicates that individual characteristics (age and gender) influence interpersonal space preferences and that some variation in results can be explained by temperature in a given region. We also present objective values of preferred interpersonal distances in different regions, which might be used as a reference data point in future studies.

The Associations of Dyadic Coping and Relationship Satisfaction Vary between and within Nations: A 35-Nation Study

OBJECTIVE

Theories about how couples help each other to cope with stress, such as the systemic transactional model of dyadic coping, suggest that the cultural context in which couples live influences how their coping behavior affects their relationship satisfaction. In contrast to the theoretical assumptions, a recent meta-analysis provides evidence that neither culture, nor gender, influences the association between dyadic coping and relationship satisfaction, at least based on their samples of couples living in North America and West Europe. Thus, it is an open questions whether the theoretical assumptions of cultural influences are false or whether cultural influences on couple behavior just occur in cultures outside of the Western world.

METHOD

In order to examine the cultural influence, using a sample of married individuals (N = 7973) from 35 nations, we used multilevel modeling to test whether the positive association between dyadic coping and relationship satisfaction varies across nations and whether gender might moderate the association.

RESULTS

RESULTS reveal that the association between dyadic coping and relationship satisfaction varies between nations. In addition, results show that in some nations the association is higher for men and in other nations it is higher for women.

CONCLUSIONS

Cultural and gender differences across the globe influence how couples' coping behavior affects relationship outcomes. This crucial finding indicates that couple relationship education programs and interventions need to be culturally adapted, as skill trainings such as dyadic coping lead to differential effects on relationship satisfaction based on the culture in which couples live.

[Position Paper of the Youth Forum DGOU 2010 - part 1]

The aim of the "Youth Forum of the DGOU" during the Convention 2010 in Heidelberg was to place a statement concerning the professional politics in the field of Orthopaedic and Trauma Surgery. The emigration of young German physicians, the occupational image of the Physician Assistant and the quality of the German residency programs in Orthopaedic and Trauma Surgery we discussed as main topics. The main reason for young German physicians to go abroad is, besides better work conditions and less bureaucracy, the better structured education during residency. Therefore the "Youth Forum" generally supports the concept of the "physician assistant" as "a relief from non-physician duties rather than discussing the delegation of true physician duties". The "Youth Forum" is looking forward to collaborating on the improvement of the ongoing education of residents. In this regard, Orthopaedic and Trauma Surgery needs to become more attractive for young academics. We also support a uniform and nationwide curriculum, which guarantees a structured education to improve the theoretic, practical and academic skills of the future specialist in orthopaedic and trauma surgery. Additional surveys and interviews among the current generation of residents are needed to further specify the potential goals of such a curriculum. We would like to discuss the future of our speciality with our colleagues. Therefore different communication platforms including our website http://www.jf-dgou.de have been created.

Attractiveness of Leg Length: Report From 27 Nations

The leg-to-body ratio (LBR) is a morphological index that has been shown to influence a person’s attractiveness. In our research, 3,103 participants from 27 nations rated the physical attractiveness of seven male and seven female silhouettes varying in LBR. We found that male and female silhouettes with short and excessively long legs were perceived as less attractive across all nations. Hence, the LBR may significantly influence perceptions of physical attractiveness across nations.