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Somitogenesis is a hallmark feature of all vertebrates and some invertebrate species that involves the periodic formation of block-like structures called somites. Somites are transient embryonic segments that eventually establish the entire vertebral column. A highly conserved molecular oscillator called the segmentation clock underlies this periodic event and the pace of this clock regulates the pace of somite formation. Although conserved signaling pathways govern the clock in most vertebrates, the mechanisms underlying the speciesspecific divergence in various clock characteristics remain elusive. For example, the segmentation clock in classical model species such as zebrafish, chick, and mouse embryos tick with a periodicity of ~30, ~90, and ~120 min respectively. This enables them to form the species-specific number of vertebrae during their overall timespan of somitogenesis. Here, we perform a systematic review of the species-specific features of the segmentation clock with a keen focus on mouse embryos. We perform this review using three different perspectives: Notchresponsive clock genes, ligand-receptor dynamics, and synchronization between neighboring oscillators. We further review reports that use non-classical model organisms and in vitro model systems that complement our current understanding of the segmentation clock. Our review highlights the importance of comparative developmental biology to further our understanding of this essential developmental process. [ABSTRACT FROM AUTHOR]

Background: Every year, 350,000 people die from cardiac arrest. However, cardiopulmonary resuscitation (CPR) can double or triple an individual's chance of survival after cardiac arrest. Global CPR Training aims to spread awareness and educate our communities on this life-saving skill, focusing our attention on rural and low-income communities that have higher average emergency response times. Methods: Our free training courses are based on the American Red Cross material and are hour-long classes condensed to efficiently and effectively teach CPR, known as an IMPACT course. These classes are held at the University of Texas at Dallas in designated classrooms and at Stacy Montessori Academy. Participants of our efficacy study are given an emergency cardiac arrest scenario and are scored in a pre-test and post-test based on the completion of specific CPR steps. The instructor provides no prompts, and the results are not shared with the participants. Results: Based on the current analysis of pre-test and posttest results, the Global CPR Training course has resulted in a 185.5% increase in cardiac arrest and CPR knowledge immediately following the class. Conclusions: A future examination will be given one year after each class to verify the validity of our training. Furthermore, to improve the quality of our course, we are receiving feedback from all participants via online survey forms that instructors analyze following every class. The program is expected to increase CPR knowledge and skill retention while also improving out-of-hospital health outcomes involving cardiac arrest in rural and low-income communities. [ABSTRACT FROM AUTHOR]

TheSARS-CoV-2 virus caused a pandemic affecting healthcare deliveryglobally. Despite the presentation of COVID-19 infection beingfrequently dominated by respiratory symptoms; it is now notorious tohave potentially serious cardiovascular sequelae. This articleexplores current data to provide a comprehensive overview of thepathophysiology, cardiovascular risk factors, and implications ofCOVID-19. Inherentstructure of SARS-CoV-2, and its interaction with both ACE-2 andnon-ACE-2 mediated pathways have been implicated in the developmentof cardiovascular manifestations, progressively resulting in acuterespiratory distress syndrome, multiorgan failure, cytokine releasesyndrome, and subsequent myocardial damage. The interplay betweenexisting and de novo cardiac complications must be noted. Forindividuals taking cardiovascular medications, pharmacologicinteractions are a crucial component. Short-term cardiovascularimpacts include arrhythmia, myocarditis, pericarditis, heart failure,and thromboembolism, whereas long-term impacts include diabetes andhypertension. To identify suitable studies, a PubMed literaturesearch was performed including key words such as 'Covid 19,''Cardiovascular disease,' 'Long covid,' etc. Moresophisticated planning and effective management for cardiologyhealthcare provision is crucial, especially for accommodatingchallenges associated with Long-COVID. With the potential applicationof AI and automated data, there are many avenues and sequelae thatcan be approached for investigation. Deemed the pandemic of the century, COVID-19 is an illness affecting multiple organ systems. Although the virus is best known for its lung-related complications, its adverse effects on the heart and blood vessels are now becoming more apparent. Rapidly mutating and evolving, its unique structure enables it to undergo interactions with various proteins in the body, resulting in complications of both the heart itself and blood vessels throughout the body. Numerous risk factors have been identified to facilitate these manifestations, including existing heart disease, medication usage, and age. Research has shown that certain drug interactions induce disturbances of the heart rhythm and function. In addition to this, they can also exacerbate preexisting heart-related complications, resulting in severe manifestations. The effects on the heart and blood vessels can be divided into acute and chronic complications. Acute complications include heart failure, rhythm disturbances, heart muscle weakness, and inflammation. In addition to this, chronic complications such as high blood pressure and the new onset of diabetes could also be a consequence. Further research is necessary to improve and enhance both our understanding of the virus and our ability to anticipate heart-related symptoms early on. [ABSTRACT FROM AUTHOR]

Resistance drift in phase change memory (PCM) reduces the accuracy of analog computing applications such as neural network inference. Recently, PCMs based on superlattice (SL) phase change layers have shown low resistance drift, however the origin of this low drift remains unexplored. Here, we uncover that resistance drift in SL-PCM based on alternating layers of Sb2Te3 and Ge2Sb2Te5 (GST) is controlled by the number of SL interfaces as well as the degree of SL intermixing. Temperature-dependent measurements reveal smaller and more stable activation energy upon annealing (thus suppressed structural relaxation) in our SL-PCM vs. control GST devices, accounting for the low resistance drift. By controlling SL interfaces, we achieve low resistance drift coefficient ${v} < 0.01$ in these SL-PCMs, maintained after extensive cycling and at various read voltages and intervals - showing robustness required for analog computing with PCM. [ABSTRACT FROM AUTHOR]

Membrane based separations offer an inexpensive and energy efficient pathway to purification. However, their use is often stifled during separation of organics due to low selectivity. This can be attributed to the inherent limitations of the synthesis methods employed, namely, interfacial polymerization and phase inversion. In this work, a new class of structure-by-design membranes are synthesized by surface modification of crosslinked polyimide using graft polymerization with a series of methacrylate monomers with differing chain lengths and chemistries. Graft polymerization of long chain monomers resulted in increased selectivity (α∼3.7 for 80-20 mol.% MeOH-toluene and α∼6 for 95-5 mol.% toluene-triisopropyl benzene (TIPB) for both test solutions) as a result of increased stiffness and order (using GIWAXS)). The observed selectivities renders these membranes competitive for organic solvent nanofiltration applications. In addition, pure solvent permeabilities were measured. The performance of these membranes was correlated with brush properties such as degree of grafting (using ATR-FTIR), surface polarity (contact angle measurements), stiffness (using QCM-D) and brush configuration in different solvent environments (using MD Simulations). MD simulations demonstrate that in mixtures containing hydrophobic species, polymers with longer hydrophobic side chains well more and form fuller matrices leading to increased solvent accessible surface area. GIWAXS results showed increased order with longer side chain length. These tunable membranes offer promise for organics separation. [Display omitted] • Tunable structure by design for polymer membranes. • Correlated brush length and brush chemistry with membrane selectivity. • Selectivity of 3.7 for methanol-toluene and ∼6 for toluene-TIPB mixtures. [ABSTRACT FROM AUTHOR]

Synthetic polymeric nanofiltration membrane processes offer an alternate low-energy option to energy-intensive distillation to fractionate similar size organic solvents for chemical, petroleum, food and biotechnology industries. Here, we synthesize and test a new class of structure-by-design hydrophilic polymeric brush membranes, that address the limitations of commercial polymer membranes, are tunable and exhibit commercially relevant filtration performance. Because these brush membranes are grafted by Single Electron Transfer-Living Radical Polymerization (SET-LRP) and replace statistically random phase inversion or interfacial polymerization used for synthesizing commercial polymer membranes, their porous structure can be remodeled by varying their morphology and chemistry. We graft hydroxyethyl methacrylate (HEMA) brush structures with short and long crosslinkers, demonstrate two competing phenomena - pore stiffening and opening - and obtain high selectivity at reasonable permeability for commercially relevant methanol/toluene separation. This new class of stable, tunable, and scalable membranes offers exciting opportunities to reduce energy for separation of organic solvents. [Display omitted] • Tunable 'structure-by-design' for polymer membranes. • Relatively green, scalable and inexpensive surface modification. • Selectivity of 3.7 for methanol-toluene organic solvent mixtures. • Correlating polymer stiffening and pore opening with selectivity. [ABSTRACT FROM AUTHOR]

A novel surface modification technique for polyimide membranes, their characterization and organic solvent filtration performance is described. The process involves treating crosslinked polyimide support membranes with surface initiators followed by Single Electron Transfer - Living Radical Polymerization (SET-LRP) with three alkyl methacrylates. Proof of grafting is established using ATR-FTIR, XPS and FESEM. The degree of grafting (DG) and brush height were a function of monomer type and polymerization time and provide a unifying basis for correlating selectivity and permeability. The permeability of these composite membranes, evaluated with 6 organic solvents (alcohols), correlated with solvent properties and can be tailored with DG. Filtration performance was assessed by measuring the selectivity and fouling of the organic dye Rose Bengal (RB) in ethanol. The polarized wall concentration increased with DG, whereas the RB sieving coefficient decreased with DG. Flux decline during RB filtration was best described by pore blocking and by heterogeneous and Langmuir sorption models. These studies provide a basis for designing polymeric membranes comprising branched brush selective layers with defined microstructure not possible with the widely popular phase inversion process. Image 1 • Novel surface modification technique, Single Electron Transfer - Living Radical Polymerization. • Membrane performance linked to degree of grafting. • Tunable brush length for organic solvent nanofiltration. • Fouling models to describe flux decline. [ABSTRACT FROM AUTHOR]

Reliable measurement of permeability of membranes with respect of different chemical compounds is of paramount importance for the design of novel materials for selective separations, protective barriers against chemical warfare agents and toxic industrial chemicals. An original in-situ Raman spectroscopy experimental setup is devised to measure the dynamics of permeation of toxins with example of diffusion of dimethyl methylphosphonate (DMMP), a nerve agent surrogate, across polyelectrolyte composite membranes. Efficiency of the proposed method is demonstrated on two types of commercial membranes, Nafion 117 and Nexar MD9200, modified with metal oxide nanoparticles. It was found that loading membranes with ZnO nanoparticles significantly reduces agent permeation, enhancing its protective capabilities against hazardous substances. The proposed methodology can be adopted and applied for characterization of permeability of other types of CWAs, their simulants, and other chemicals through polymeric membranes of different origin. • Polyelectrolyte composite membranes exhibit chemical protection capabilities. • An original in-situ Raman experimental setup was used to assess chemical protection. • Incorporation of ZnO nanoparticles enhances chemical protection of membranes. [ABSTRACT FROM AUTHOR]