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Foods (Basel, Switzerland) Mar 2024Beekeeping directly depends on the floral biodiversity available to honey bees. In tropical regions, where nectar and pollen resources are numerous, the botanical origin...
Beekeeping directly depends on the floral biodiversity available to honey bees. In tropical regions, where nectar and pollen resources are numerous, the botanical origin of some honey is still under discussion. A precise knowledge of plants foraged by honey bees is useful to understand and certify the botanical origin of honey. In this study, attention was paid to honey samples from the French Guiana Atlantic coast where beekeepers generally place their hives in four types of biotopes: seaside vegetation, mangrove, savannah, and secondary forest. Pollen analysis of 87 honey samples enabled the identification of major plants visited by Africanized honey bees during the dry season (approximately from July to January). Through melissopalynologic analysis, 51 pollen types were identified and classified according to their relative presence. Frequently observed pollens (with relative presence > 50%) in French Guiana kinds of honey were those from , sp., sp., , sp., , , sp., Myrtaceae sp., sp., sp., and sp. In many honeys, only was over-represented (relative frequency > 90%). Color and electrical conductivity in French Guiana honeys exhibit significant variations, with color ranging from 27 mm to 110 mm Pfund, and electrical conductivity ranging from 0.35 to 1.22 mS/cm.
PubMed: 38611377
DOI: 10.3390/foods13071073 -
BioRxiv : the Preprint Server For... May 2024Antimicrobial resistance is an emerging global threat to humanity. As resistance outpaces development, new perspectives are required. For decades, scientists have...
Antimicrobial resistance is an emerging global threat to humanity. As resistance outpaces development, new perspectives are required. For decades, scientists have prioritized chemical optimization, while largely ignoring the physical process of delivery. Here, we used biophysical simulations and microfluidic experiments to explore how fluid flow delivers antimicrobials into communities of the highly resistant pathogen . We discover that increasing flow overcomes bacterial resistance towards three chemically distinct antimicrobials: hydrogen peroxide, gentamicin, and carbenicillin. Without flow, resistant cells generate local zones of depletion by neutralizing all three antimicrobials through degradation or chemical modification. As flow increases, delivery overwhelms neutralization, allowing antimicrobials to regain effectiveness against resistant bacteria. Additionally, we discover that cells on the edge of a community shield internal cells, and cell-cell shielding is abolished in higher flow regimes. Collectively, our quantitative experiments reveal the unexpected result that physical flow and chemical dosage are equally important to antimicrobial effectiveness. Thus, our results should inspire the incorporation of flow into the discovery, development, and implementation of antimicrobials, and could represent a new strategy to combat antimicrobial resistance.
PubMed: 38766052
DOI: 10.1101/2024.05.08.591722 -
Frontiers in Psychology 2023
PubMed: 38111863
DOI: 10.3389/fpsyg.2023.1334171 -
Accounts of Materials Research Jul 2023
PubMed: 38737440
DOI: 10.1021/accountsmr.3c00061 -
Sensors (Basel, Switzerland) Feb 2024The construction of large-diameter shield tunnels underwater involves complex variations in water and earth load outside the tunnel segment, as well as intricate...
The construction of large-diameter shield tunnels underwater involves complex variations in water and earth load outside the tunnel segment, as well as intricate mechanical responses. This study analyzes the variation laws of external loads, axial forces, and bending moments acting on the segment ring during the shield assembly and removal from the shield tail. It accomplishes this through the establishment of an on-site monitoring system based on the Internet of Things (IoT) and proposes a Bayesian-genetic algorithm model to estimate the water and earth pressure. The fluctuation section exhibits a peak load twice as high as that in the stable section. These variations are influenced by Jack thrust, shield shell force, and grouting pressure. The peak load observed in the fluctuation section is twice as high as the load observed in the stable section. During the shield tail removal process, the internal forces undergo significant fluctuations due to changes in both load and boundary conditions, and the peak value of the axial force during the fluctuation section is eight times higher than that during the stable section, while the peak value of the bending moment during the fluctuation section is five times higher than that during the stable section. The earth and water pressure calculated using the inversion analysis method, which relies on the measured internal forces, closely matches the actual measured values. The results demonstrate that the accuracy of the water and earth pressure obtained through inversion analysis is twice as high as that obtained using the full coverage pressure method. These results can serve as a valuable reference for similar projects.
PubMed: 38400469
DOI: 10.3390/s24041310 -
Nano-micro Letters Jul 2023Composite organohydrogels have been widely used in wearable electronics. However, it remains a great challenge to develop mechanically robust and multifunctional...
Composite organohydrogels have been widely used in wearable electronics. However, it remains a great challenge to develop mechanically robust and multifunctional composite organohydrogels with good dispersion of nanofillers and strong interfacial interactions. Here, multifunctional nanofiber composite reinforced organohydrogels (NCROs) are prepared. The NCRO with a sandwich-like structure possesses excellent multi-level interfacial bonding. Simultaneously, the synergistic strengthening and toughening mechanism at three different length scales endow the NCRO with outstanding mechanical properties with a tensile strength (up to 7.38 ± 0.24 MPa), fracture strain (up to 941 ± 17%), toughness (up to 31.59 ± 1.53 MJ m) and fracture energy (up to 5.41 ± 0.63 kJ m). Moreover, the NCRO can be used for high performance electromagnetic interference shielding and strain sensing due to its high conductivity and excellent environmental tolerance such as anti-freezing performance. Remarkably, owing to the organohydrogel stabilized conductive network, the NCRO exhibits superior long-term sensing stability and durability compared to the nanofiber composite itself. This work provides new ideas for the design of high-strength, tough, stretchable, anti-freezing and conductive organohydrogels with potential applications in multifunctional and wearable electronics.
PubMed: 37420043
DOI: 10.1007/s40820-023-01148-9 -
Signal Transduction and Targeted Therapy Apr 2024Circulating tumor cells (CTCs) are precursors of distant metastasis in a subset of cancer patients. A better understanding of CTCs heterogeneity and how these CTCs...
Circulating tumor cells (CTCs) are precursors of distant metastasis in a subset of cancer patients. A better understanding of CTCs heterogeneity and how these CTCs survive during hematogenous dissemination could lay the foundation for therapeutic prevention of cancer metastasis. It remains elusive how CTCs evade immune surveillance and elimination by immune cells. In this study, we unequivocally identified a subpopulation of CTCs shielded with extracellular vesicle (EVs)-derived CD45 (termed as CD45 CTCs) that resisted T cell attack. A higher percentage of CD45 CTCs was found to be closely correlated with higher incidence of metastasis and worse prognosis in cancer patients. Moreover, CD45 tumor cells orchestrated an immunosuppressive milieu and CD45 CTCs exhibited remarkably stronger metastatic potential than CD45 CTCs in vivo. Mechanistically, CD45 expressing on tumor surfaces was shown to form intercellular CD45-CD45 homophilic interactions with CD45 on T cells, thereby preventing CD45 exclusion from TCR-pMHC synapse and leading to diminished TCR signaling transduction and suppressed immune response. Together, these results pointed to an underappreciated capability of EVs-derived CD45-dressed CTCs in immune evasion and metastasis, providing a rationale for targeting EVs-derived CD45 internalization by CTCs to prevent cancer metastasis.
Topics: Humans; Extracellular Vesicles; Neoplastic Cells, Circulating; Receptors, Antigen, T-Cell; T-Lymphocytes
PubMed: 38575583
DOI: 10.1038/s41392-024-01789-1 -
Scientific Reports Mar 2024In tropical disaster victim identification (DVI) scenarios, challenging environmental conditions lead to accelerated DNA degradation in remains. To further enhance the...
In tropical disaster victim identification (DVI) scenarios, challenging environmental conditions lead to accelerated DNA degradation in remains. To further enhance the utilization of leached DNA from tissue in the preservative solution (termed "free DNA") as an alternative source, we incorporated new results by assessing its integrity in postmortem and decomposing cadavers preserved in DNA/RNA Shield™ and modified TENT, with silica-based purification (QIAquick) for faster processing. The psoas muscle tissues of one decomposed and ten cadavers were preserved in each solution at 25 °C and 35 °C for 3 months. Free DNA efficiency was compared with individual reference samples for reliable results in quantity, quality, and STR profiles. The findings revealed that DNA/RNA Shield™ effectively preserves free DNA integrity for extended storage, while modified TENT is more suitable for short-term storage due to higher degradation levels. Moreover, the use of free DNA samples with massive parallel sequencing displays potential for forensic DNA analysis. Successful amplification of the mtDNA control region enables variant calling and heteroplasmy analysis while also serving as quality control using ACTB and enabling differentiation within the 16S rRNA region for microbiome analysis. The simplicity of handling free DNA for PCR-based forensic analysis adds to its potential for various applications, including DVI and field-based analysis of biological evidence.
Topics: Humans; Disaster Victims; Feasibility Studies; RNA, Ribosomal, 16S; DNA, Mitochondrial; Cadaver
PubMed: 38443390
DOI: 10.1038/s41598-024-53040-0 -
Proceedings of the National Academy of... Aug 2023This paper presents an approach to Solar Radiation Management (SRM) using a tethered solar shield at the modified gravitational L1 Lagrange point. Unlike previous...
This paper presents an approach to Solar Radiation Management (SRM) using a tethered solar shield at the modified gravitational L1 Lagrange point. Unlike previous proposals, which were constrained by the McInnes bound on shield surface density, our proposed configuration with a counterweight toward the Sun circumvents this limitation and potentially reduces the total mass by orders of magnitude. Furthermore, only 1% of the total weight must come from Earth, with ballast from lunar dust or asteroids serving as the remainder. This approach could lead to a significant cost reduction and potentially be more effective than previous space-based SRM strategies.
PubMed: 37523526
DOI: 10.1073/pnas.2307434120 -
BMC Musculoskeletal Disorders Nov 2023Porous cages are considered a promising alternative to high-density cages because their interconnectivity favours bony ingrowth and appropriate stiffness tuning reduces...
BACKGROUND
Porous cages are considered a promising alternative to high-density cages because their interconnectivity favours bony ingrowth and appropriate stiffness tuning reduces stress shielding and the risk of cage subsidence.
METHODS
This study proposes three approaches that combine macroscopic topology optimization and micropore design to establish three new types of porous cages by integrating lattices (gyroid, Schwarz, body-centred cubic) with the optimized cage frame. Using these three porous cages along with traditional high-density cages, four ACDF surgical models were developed to compare the mechanical properties of facet articular cartilage, discs, cortical bone, and cages under specific loads.
RESULTS
The facet joints in the porous cage groups had lower contact forces than those in the high-density cage group. The intervertebral discs in all models experienced maximum stress at the C5/6 segment. The stress distribution on the cortical bone surface was more uniform in the porous cage groups, leading to increased average stress values. The gyroid, Schwarz, and BCC cage groups showed higher average stress on the C5 cortical bone. The average stress on the surface of porous cages was higher than that on the surface of high-density cages, with the greatest difference observed under the lateral bending condition. The BCC cage demonstrated favourable mechanical stability.
CONCLUSION
The new porous cervical cages satifies requirements of low rigidity and serve as a favourable biological scaffold for bone ingrowth. This study provides valuable insights for the development of next-generation orthopaedic medical devices.
Topics: Humans; Porosity; Finite Element Analysis; Spinal Diseases; Intervertebral Disc; Spinal Fusion; Biomechanical Phenomena; Cervical Vertebrae
PubMed: 37950220
DOI: 10.1186/s12891-023-06999-2