Biomimetics of microducts in three-dimensional bacterial nanocellulose biomaterials for soft tissue regenerative medicine

The demand for solid organs is increasing worldwide, regenerative medicine aims to develop organs that can replace their human counterparts. In this regard, this study describes a novel biomimetic-based methodology for the incorporation of microducts in 3D bacterial nanocellulose (BNC-3D) biomaterials. Although BNC is a biomaterial that has been used as a scaffold for cell culture purposes, it does not have the microduct structure that solid organs required to maintain cell viability. This study aims to biomimicry the microduct structure (blood vessels) in BNC using a corroded porcine kidney in epoxy resin during BNC synthesis. The resin mold was incorporated into the biological process of producing BNC-3D. After the BNC fermentation, the resin was removed using a novel method (acid hydrolysis) to expose the blood vessels constructs. BNC-3D and BNC-3D with microducts (BNC-3DM) were analyzed using electronic microscopy, infrared analysis, thermogravimetric and biological analysis. Results show that biomaterials biomimicry the blood vessels of the reference organ, moreover, the BNC chemical and morphological properties of BNC was not affected in the biomimetic process. Regarding cell behavior, cell viability was not affected by the incorporation of the microducts, and it was proven that viable cells adhere to the microducts surface, reproducing their shape and migrate into the biomaterial up to 245 mu m for 8 days of culture. To conclude, the data demonstrate the potential of biomimetic in BNC for regenerative medicine, in which the microducts transport fluids (blood, nutrients, and waste products) from and to engineered solid organs via animal counterparts. Graphic abstract The graphical abstract represents the structural modification of bacterial nanocellulose (BNC) with the inclusion of microducts and microporosities. Furthermore, it represents the usefulness of the microducts in future applications, where, they can be used for nutrients inlet to feed the cells and to remove the wastes from the developed tissue, same as do the blood vessels. [GRAPHICS]

Gas Dynamic Virtual Nozzle for Generation of Microscopic Droplet Streams

As shown by Ganan-Calvo and co-workers, a free liquid jet can be compressed in iameter through gas-dynamic forces exerted by a co-flowing gas, obviating the need for a solid nozzle to form a microscopic liquid jet and thereby alleviating the clogging problems that plague conventional droplet sources of small diameter. We describe in this paper a novel form of droplet beam source based on this principle. The source is miniature, robust, dependable, easily fabricated, and eminently suitable for delivery of microscopic liquid droplets, including hydrated biological samples, into vacuum for analysis using vacuum instrumentation. Monodisperse, single file droplet streams are generated by triggering the device with a piezoelectric actuator. The device is essentially immune to clogging

Filosofía ambiental de campo: Educación e investigación para la valoración ecológica y ética de los insectos dulceacuícolas (Field environmental philosophy: education and research for the ecological and ethical appreciation of freshwater insects)

In a rapidly changing world, to confront biodiversity losses and the lack of appreciation for and knowledge about the most diverse groups of organisms, it is urgently necessary to stimulate cultural shifts that transcend purely scientific and technological domains. This paper addresses this problem by focusing on one of the least known groups of organisms, and in one of the most remote regions of the planet: freshwater insects in the sub-Antarctic Magellanic ecoregion. The work of this thesis included scientific-ecological and environmental philosophical research that was integrated into formal and non-formal environmental education practices that value freshwater insects, particularly as indicators of climate change. The integration of science and philosophy was done adapting the Field Environmental Philosophy methodology that includes a four-step cycle. Transdisciplinary research on freshwater insects and their sub-Antarctic ecosystems served as a basis for the composition of metaphors and educational activities with schoolchildren, other members of the local community and visitors to Omora Park, in Puerto Williams, Chile. Based on this work, new outdoor educational activities were designed with the objective of awakening the interest of citizens for insects, and nurturing their perceptions about these organisms, their habitats and life habits. In this way, at a local scale this work aims to contribute to greater knowledge, appreciation and conservation of this unique sub-Antarctic biodiversity, and at a global scale it aims to contribute overcoming the under-appreciation for the most diverse group of organisms: the insects

Exploring efficient seamless handover in VANET systems using network dwell time

Vehicular ad hoc networks are a long-term solution contributing significantly towards intelligent transport systems (ITS) in providing access to critical life-safety applications and services. Although vehicular ad hoc networks are attracting greater commercial interest, current research has not adequately captured the real-world constraints in vehicular ad hoc network handover techniques. Therefore, in order to have the best practice for vehicular ad hoc network services, it is necessary to have seamless connectivity for optimal coverage and ideal channel utilisation. Due to the high velocity of vehicles and smaller coverage distances, there are serious challenges in providing seamless handover from one roadside unit (RSU) to another. Though other research efforts have looked at many issues in vehicular ad hoc networks (VANETs), very few research work have looked at handover issues. Most literature assume that handover does not take a significant time and does not affect the overall VANET operation. In our previous work, we started to investigate these issues. This journal provides a more comprehensive analysis involving the beacon frequency, the size of beacon and the velocity of the vehicle. We used some of the concepts of Y-Comm architecture such as network dwell time (NDT), time before handover (TBH) and exit time (ET) to provide a framework to investigate handover issues. Further simulation studies were used to investigate the relation between beaconing, velocity and the network dwell time. Our results show that there is a need to understand the cumulative effect of beaconing in addition to the probability of successful reception as well as how these probability distributions are affected by the velocity of the vehicle. This provides more insight into how to support life critical applications using proactive handover techniques

Targeting the EIF2AK1 Signaling Pathway Rescues Red Blood Cell Production in SF3B1 Mutant Myelodysplastic Syndromes With Ringed Sideroblasts

View full abstracthttps://openworks.mdanderson.org/leading-edge/1025/thumbnail.jp

Stem cell architecture drives myelodysplastic syndrome progression and predicts response to venetoclax-based therapy

Myelodysplastic syndromes (MDS) are heterogeneous neoplastic disorders of hematopoietic stem cells (HSCs). The current standard of care for patients with MDS is hypomethylating agent (HMA)-based therapy; however, almost 50% of MDS patients fail HMA therapy and progress to acute myeloid leukemia, facing a dismal prognosis due to lack of approved second-line treatment options. As cancer stem cells are the seeds of disease progression, we investigated the biological properties of the MDS HSCs that drive disease evolution, seeking to uncover vulnerabilities that could be therapeutically exploited. Through integrative molecular profiling of HSCs and progenitor cells in large patient cohorts, we found that MDS HSCs in two distinct differentiation states are maintained throughout the clinical course of the disease, and expand at progression, depending on recurrent activation of the anti-apoptotic regulator BCL-2 or nuclear factor-kappa B-mediated survival pathways. Pharmacologically inhibiting these pathways depleted MDS HSCs and reduced tumor burden in experimental systems. Further, patients with MDS who progressed after failure to frontline HMA therapy and whose HSCs upregulated BCL-2 achieved improved clinical responses to venetoclax-based therapy in the clinical setting. Overall, our study uncovers that HSC architectures in MDS are potential predictive biomarkers to guide second-line treatments after HMA failure. These findings warrant further investigation of HSC-specific survival pathways to identify new therapeutic targets of clinical potential in MDS

Effects of mannoprotein E1 in liquid diet on inflammatory response and TLR5 expression in the gut of rats infected by Salmonella typhimurium

<p>Abstract</p> <p>Background</p> <p>Mannoproteins are yeast cell wall componend, and rich in mannose. The use of foods rich in mannose as carbohydrate, could have a bioprotective effect against entrobacteria intestinal infection. Nothing is known about mannoproteins' activity in inflammatory bowel processes induced by entrobacteria.</p> <p>This study investigates the effects of mannoprotein administration via a liquid diet on inflammatory response and TLR5 expression during intestinal tissue injury in a rat model of infection with <it>Salmonella typhimurium</it>.</p> <p>Methods</p> <p>Adult Wistar male rats were divided into three groups: control, and mannoprotein E₁at 10 or 15%. Animals were fed with a liquid diet supplemented or not with mannoprotein E₁. Groups were infected by intragastrical administration of <it>S. typhimurium</it>. 24 h post-inoculation samples of spleen, ileum and liver were collected for microbiological studies. Gut samples were processed to determine levels of proinflammatory cytokines (mRNA) and TLR5 (mRNA and protein) by quantitative PCR and Western-blot, and the number of proliferative and apoptotic cells determined by immunohistochemistry.</p> <p>Results</p> <p>Ininfected levels of proinflammatory cytokines and TLR5 were higher in untreated controls than in the animals receiving mannoprotein. Proliferation was similar in both groups, whereas apoptosis was higher in controls. Curiosly, the mannoprotein effect was dose dependent.</p> <p>Conclusions</p> <p>Mannoprotein administration in a liquid diet seems to protect intestinal tissue against <it>S. typhimurium </it>infection. This protection seems to expressed as a lower pro-inflammatory response and TLR5 downregulation in gut epithelium, as well as by an inhibition of apoptosis. Nevertheless, the molecular mechanism by which mannoprotein is able to regulate these responses remain unclear. These results could open up new avenues in the use of mannoproteins as prebiotics in the therapeutic strategy for treatment of inflammatory gut processes induced by microbia.</p

The Epidemiology, Genetics and Future Management of Syndactyly

Syndactyly is a condition well documented in current literature due to it being the most common congenital hand defect, with a large aesthetic and functional significance