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1. Genetic and physical interactions between the organellar mechanosensitive ion channel homologs MSL 1, MSL 2, and MSL 3 reveal a role for inter‐organellar communication in plant development

   https://doi.org/10.1002/pld3.124  

   Lee, Josephine S. ; Wilson, Margaret E. ; Richardson, Ryan A. ; Haswell, Elizabeth S. ( March 2019 , Plant Direct)

   Plant development requires communication on many levels, including between cells and between organelles within a cell. For example, mitochondria and plastids have been proposed to be sensors of environmental stress and to coordinate their responses. Here we present evidence for communication between mitochondria and chloroplasts during leaf and root development, based on genetic and physical interactions between threeMechanosensitive channel ofSmall conductance‐Like (MSL) proteins fromArabidopsis thaliana.MSLproteins areArabidopsishomologs of the bacterialMechanosensitivechannel ofSmall conductance (MscS), which relieves cellular osmotic pressure to protect against lysis during hypoosmotic shock.MSL1 localizes to the inner mitochondrial membrane, whileMSL2 andMSL3 localize to the inner plastid membrane and are required to maintain plastid osmotic homeostasis during normal growth and development. In this study, we characterized the phenotypic effect of a genetic lesion inMSL1, both in wild type and inmsl2 msl3mutant backgrounds.msl1single mutants appear wild type for all phenotypes examined. The characteristic leaf rumpling inmsl2 msl3double mutants was exacerbated in themsl1 msl2 msl3triple mutant. However, the introduction of themsl1lesion into themsl2 msl3mutant background suppressed othermsl2 msl3mutant phenotypes, including ectopic callus formation, accumulation of superoxide and hydrogen peroxide in the shoot apical meristem, decreased root length, and reduced number of lateral roots. All these phenotypes could be recovered by molecular complementation with a transgene containing a wild type version ofMSL1. In yeast‐based interaction studies,MSL1 interacted with itself, but not withMSL2 orMSL3. These results establish that the abnormalities observed inmsl2 msl3double mutants is partially dependent on the presence of functionalMSL1 and suggest a possible role for communication between plastid and mitochondria in seedling development.

    

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2. Continuous CTC separation through a DEP ‐based contraction–expansion inertial microfluidic channel

   https://doi.org/10.1002/btpr.3341  

   Islam, Md Sadiqul ; Chen, Xiaolin ( July 2023 , Biotechnology Progress)

   Abstract The efficient isolation of viable and intact circulating tumor cells (CTCs) from blood is critical for the genetic analysis of cancer cells, prediction of cancer progression, development of drugs, and evaluation of therapeutic treatments. While conventional cell separation devices utilize the size difference between CTCs and other blood cells, they fail to separate CTCs from white blood cells (WBCs) due to significant size overlap. To overcome this issue, we present a novel approach that combines curved contraction–expansion (CE) channels with dielectrophoresis (DEP) and inertial microfluidics to isolate CTCs from WBCs regardless of size overlap. This label‐free and continuous separation method utilizes dielectric properties and size variation of cells for the separation of CTCs from WBCs. The results demonstrate that the proposed hybrid microfluidic channel can effectively isolate A549 CTCs from WBCs regardless of their size with a throughput of 300 μL/min, achieving a high separation distance of 233.4 μm at an applied voltage of 50 V p–p . The proposed method allows for the modification of cell migration characteristics by controlling the number of CE sections of the channel, applied voltage, applied frequency, and flow rate. With its unique features of a single‐stage separation, simple design, and tunability, the proposed method provides a promising alternative to the existing label‐free cell separation techniques and may have a wide range of applications in biomedicine. 

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3. Multi‐channel helical‐antenna inner‐volume RF coils for ultra‐high field MR scanners

   https://doi.org/10.1002/cmr.b.21405  

   Athalye, Pranav S. ; Ilić, Milan M. ; van de Moortele, Pierre‐Francois ; Kiruluta, Andrew J. M. ; Notaroš, Branislav M. ( February 2019 , Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering)

   RFcoil design for human ultra‐high field (7 T and higher) magnetic resonance (MR) imaging is an area of intense development, to overcome difficult challenges such asRFexcitation spatial heterogeneity and lowRFtransfer efficiency into the spin system. This article proposes a novel category of multi‐channelRFvolume coil structures at both 7 T and 10.5 T based on a subject‐loaded multifilar helical‐antennaRFcoil that aims at addressing these problems. In some prior applications of helix antennas asMR RFcoils at 7 T, the imaged sample was positioned outside the helix. Here, we introduce a radically different approach, with the inner volume of a helix antenna being utilized to image a sample. The new coil uniquely combines traveling‐wave behavior through the overall antenna wire structure and near‐fieldRFinteraction between the conducting elements and the imaged tissues. It thus benefits from the congruence of far‐ and near‐field regimes. Design and analysis of the novel inner‐volume coils are performed by numerical simulations using multiple computational electromagnetics techniques. The fabricated coil prototypes are tested, validated, and evaluated experimentally in 7‐T and 10.5‐TMRhuman wide bore (90‐cm) MRscanners. Phantom data at 7 T show good consistency between numerical simulations and experimental results. SimulatedB₁⁺transmit efficiencies, in T/√W, are comparable to those of some of the conventional and state‐of‐the‐artRFcoil designs at 7 T. Experimental results at 10.5 T show the scalability of the helix coil design.

    

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4. No evidence for induction or selection of mutant sodium channel expression in the copepod Acartia husdsonica challenged with the toxic dinoflagellate Alexandrium fundyense

   https://doi.org/10.1002/ece3.1197  

   Finiguerra, Michael ; Avery, David E. ; Dam, Hans G. ( August 2014 , Ecology and Evolution)

   Some species in the dinoflagellate genusAlexandriumspp. produce a suite of neurotoxins that block sodium channels, known as paralytic shellfish toxins (PST), which have deleterious effects on grazers. Populations of the ubiquitous copepod grazerAcartia hudsonicathat have co‐occurred with toxicAlexandriumspp. are better adapted than naïve populations. The mechanism of adaptation is currently unknown. We hypothesized that a mutation in the sodium channel could account for the grazer adaptation. We tested two hypotheses: (1) Expression of the mutant sodium channel could be induced by exposure to toxicAlexandrium fundyense; (2) in the absence of induction, selection exerted by toxicA. fundyensewould favor copepods that predominantly express the mutant isoform. In the copepodA. hudsonica, both isoforms are expressed in all individuals in varying proportions. Thus, in addition to comparing expression ratios of wild‐type to mutant isoforms for individual copepods, we also partitioned copepods into three groups: those that predominantly express the mutant (PMI) isoform, the wild‐type (PWI) isoform, or both isoforms approximately equally (EI). There were no differences in isoform expression between individuals that were fed toxic and nontoxic food after three and 6 days; induction of mutant isoform expression did not occur. Furthermore, the hypothesis that mutant isoform expression responds to toxic food was also rejected. That is, no consistent evidence showed that the wild‐type to mutant isoform ratios decreased, or that the relative proportion ofPMIindividuals increased, due to the consumption of toxic food over four generations. However, in the selected line that was continuously exposed to toxic food sources, egg production rate increased, which suggested that adaptation occurred but was unrelated to sodium channel isoform expression.

    

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5. Shear‐induced migration and axial development of particles in channel flows of non‐Brownian suspensions

   https://doi.org/10.1002/aic.17100  

   Rashedi, Ahmadreza ; Sarabian, Mohammad ; Firouznia, Mohammadhossein ; Roberts, Dallas ; Ovarlez, Guillaume ; Hormozi, Sarah ( October 2020 , AIChE Journal)

   We present an experimental study on the shear‐induced migration and axial development of particles in the channel flows of non‐Brownian suspensions. The suspending fluid is Newtonian. We investigate fracturing flows with a Hele‐Shaw type scaling through building a unique channel setup and an advanced optical system. The local particle concentration profiles are measured via the refractive‐index matching technique for a wide range of bulk volume fraction, that is,. Simultaneously, the particle image velocimetry is performed to determine the velocity profile of the particle phase. We compare our experimental results with the available two‐phase continuum frameworks and show discrepancies and similarities in the fully developed and axial development of the solid volume fraction profiles. We discuss directions in which the continuum frameworks require improvements.

    

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