Differential electrophoretic separation of cells and its effect on cell viability

An electrophoretic separation method was applied to the separation of cells. To determine the efficiency of the separation, it was necessary to apply existing methodology and develop new methods to assess the characteristics and functions of the separated subpopulations. Through appropriate application of the widely used isoelectric focusing procedure, a reproducible separation method was developed. Cells accumulated at defined pH and 70-80% remained viable. The cells were suitable for further biologic, biochemical and immunologic studies

The effects of stress on the enzymes of peripheral leukocytes

Previous work showed an early response of rabbit and human leukocyte enzymes to the stress of bacterial infection. Since these represented a mixed population of leukocytes and since polymorphonuclear leukocytes (PMN) increased in these preparations, it was necessary to establish whether the observed increase in lactate dehydrenase (LDH) and protein was the result of an increase in any one particular cell type or in all cells. The need for the development of a simple reproducible method for the differential separation of peripheral leukocytes for the furtherance of our own studies was apparent. It was also becoming increasingly apparent that morphologically similar cells, such as small lymphocytes (L) and macrophages, were capable of different biological functions. A dextran gradient centrifugation method was developed which has provided an easily reproducible technique for separating L from PMN. During the course of this work, in which over 250 rabbits were examined, the pattern of daily leukocyte protein and enzyme variation became increasingly more apparent. This information could have some impact on future work with leukocyte enzymes, by our group and by other workers. The differences in normal protein and enzyme levels maintained by some individuals, and some inbred strains, were evaluated and reported separately. It has been shown that one type of leukocyte may react more to a given stress than other leukocytes

Can a virtual reality-based rehabilitation program have a positive impact on the quality of life of adults with Multiple Sclerosis (MS)?

OBJECTIVE: The objective of this selective EBM review is to determine whether or not virtual reality based rehabilitation programs have a positive impact on the quality of life of people with MS. STUDY DESIGN: Review of 2 randomized control trials (RCTs) and one randomized control cross over pilot study written in English, two of which were published in 2013 and one in 2016. DATA SOURCES: Two randomized control trials (RCTs) and one randomized control cross over pilot study, all three non-blind, published in peer-reviewed journals found via PubMed. OUTCOME MEASURED: Quality of life was measured via Falls Efficacy Scale- International, Modified Fatigue Impact Scale, and MS Impact Scale- 29 (MSIS-29). RESULTS: All three studies showed a significant improvement quality of life in MS patients with virtual reality based training compared to conventional therapy or no physical therapy. CONCLUSION: All three studies showed that there was an increase in the quality of life in patients with MS with use of VR based training. However, further studies with larger sample sizes that examine a uniform specialized MS VR program will be needed to reinforce the conclusion that virtual reality based training is effective in improving quality of life in adults with MS

The diversity and evolution of phenazine biosynthesis pathways in Enterobacterales

Enterobacterales is an order of Gram-negative bacteria that encompasses plant and animal pathogens and organisms of industrial importance. Some of these bacteria produce secondary metabolites classified as phenazines (Phz). Studies in other groups of microorganisms revealed that phenazines are redox-active and exhibit broad antibacterial, antifungal, and antiparasitic activity. Enterobacterales are known to produce phenazines, but details about the diversity, biochemistry, and function of phenazine metabolites in these organisms are missing. In this work, we screened the National Center for Biotechnology Information (NCBI) GenBank for genome sequences of phenazine-producing (Phz+) Enterobacterales. Additionally, genomes of Phz+ strains Pectobacterium carotovorum cc303 and P. betavasculorum Ecb168 were sequenced, assembled, annotated, and used in downstream analyses. Scaffolds containing phz clusters were extracted and analyzed for the presence of the core biosynthesis, phenazine modifying, and resistance genes. These deoxyribonucleic acid (DNA) sequences were analyzed for the presence of site-specific recombinases and transposases. The evolution of phz pathways was analyzed by comparing phylogenies of the core phenazine biosynthesis and housekeeping genes. The results of this study revealed an unexpected and widespread presence of phenazine genes in Enterobacterales. We identified at least six distinct types of phenazine clusters in Escherichia coli, Shigella, Klebsiella, Enterobacter, Pantoeae, Brenneria, Serratia, Xenorhabdus, Photorhabdus, and Providencia. In many strains, phz genes formed parts of genomic islands or were associated with plasmids, suggesting their spread via horizontal gene transfer and contribution to the competition for the ecological niche between closely related taxa

Charge-Based Compact Modeling of Capacitances and Low-Frequency Noise in Organic Thin-Film Transistors

Els transistors orgànics de capa prima són candidats prometedors per a noves aplicacions electròniques a causa de la possibilitat de fabricar dispositius electrònics orgànics a baixes temperatures sobre substrats flexibles com el plàstic o el paper. Aquesta tesi doctoral tracta del desenvolupament d'un model compacte basat en la càrrega per a la descripció del comportament capacitiu i del soroll de baixa freqüència en transistors orgànics de capa prima. A partir d'un model de corrent continu existent, es deriven expressions per a les càrregues totals en condicions d'operació quasi estàtica. Els efectes no quasistàtics es capturen mitjançant diferents mètodes, com ara l'enfocament de segmentació de canals o funcions d'escalat depenents de la freqüència de les àrees del transistor on es calculen les càrregues. El model de les càrregues totals es verifica mitjançant mesures de capacitat d'un TFT orgànic esglaonat i per simulacions numèriques de TFT orgànics en les arquitectures esglaonades i coplanars mitjançant el simulador de dispositiu Sentaurus TCAD. Els models no quasistàtics es verifiquen mitjançant mesures d'admitància depenents de la freqüència d'un transistor esglaonat i per mesures de paràmetres de dispersió de transistors coplanars i esglalonats. El model compacte s'implementa en el llenguatge de descripció de hardware Verilog-A i la simulació d'un amplificador diferencial es compara amb les mesures, amb les quals es mostra un bon acord. El model de soroll es verifica mitjançant mesures de TFT orgànics esglalonats i simulacions TCAD. El model compacte mostra en general una bona concordança i flexibilitat en general pel que fa a l'arquitectura del dispositiu (per exemple, esglaonat o coplanar) i els materials utilitzats.Los transistores orgánicos de capa fina son candidatos prometedores para nuevas aplicaciones electrónicas debido a la posibilidad de fabricar dispositivos electrónicos orgánicos a bajas temperaturas en sustratos flexibles como plástico o papel. Esta tesis doctoral trata del desarrollo de un modelo compacto basado en la carga para la descripción del comportamiento capacitivo y el ruido de baja frecuencia en transistores orgánicos de capa fina. A partir de un modelo DC existente, se desarrollan expresiones para las cargas totales en condiciones de operación cuasiestáticas. Los efectos no cuasiestáticos se capturan mediante diferentes métodos, como la aproximación de segmentación del canal o las funciones de escalado dependientes de la frecuencia de las áreas del transistor donde se calculan las cargas. El modelo para las cargas totales se verifica mediante medidas de capacitancia de un TFT orgánico escalonado y mediante simulaciones numéricas de TFT orgánicos en las arquitecturas escalonada y coplanar utilizando el simulador de dispositivo TCAD Sentaurus. Los modelos no cuasiestáticos se verifican mediante medidas de admitancia dependientes de la frecuencia de un transistor escalonado y mediante medidas de parámetros de dispersión de transistores coplanares y escalonados. El modelo compacto se implementó en el lenguaje de descripción de hardware Verilog-A y la simulación de un amplificador diferencial se compara con medidas, observándose una buena concordancia. El modelo de ruido se verifica mediante medidas de TFT orgánicos escalonados y mediante simulaciones TCAD. El modelo compacto muestra en general una buena concordancia y flexibilidad con respecto a la arquitectura del dispositivo (p. ej. escalonado o coplanar) y los materiales utilizados.Organic thin-film transistors are promising candidates for novel electronics applications due to the possibility of fabricating organic electronic devices at low temperatures on flexible substrates like plastic or paper. This doctoral thesis deals with the development of a charge-based compact model for the description of the capacitive behavior and the low-frequency noise in organic thin-film transistors. Based on an existing DC model, expressions for the total charges under quasistatic operation conditions are derived. Non-quasistatic effects are captured by different methods, such as the channel-segmentation approach or frequency-dependent scaling functions of the areas in the transistor where charges are calculated. The model for the total charges is verified by capacitance measurements of a staggered organic TFT and by numerical simulations of organic TFTs in the staggered and coplanar architectures using the device simulator Sentaurus TCAD. The non-quasistatic models are verified by frequency-dependent admittance measurements of a staggered transistor and by scattering-parameter measurements of coplanar and staggered transistors. The compact model is implemented in the hardware description language Verilog-A and the simulation of a differential amplifier is compared to measurements, which shows a good agreement. The noise model is verified by measurements of staggered organic TFTs and by TCAD simulations. The compact model shows an overall good agreement and flexibility with respect to the device architecture (e. g. staggered or coplanar) and the used materials

Multiple Cdk1 Inhibitory Kinases Regulate the Cell Cycle during Development

AbstractThe Wee kinases block entry into mitosis by phosphorylating and inhibiting the activity of the mitotic cyclin-dependent kinase, Cdk1. We have found that the various Xenopus Wee kinases have unique temporal and spatial patterns of expression during development. In addition, we have isolated and characterized a new Wee1-like kinase, Xenopus Wee2. By both in vivo and in vitro tests, Xenopus Wee2 functions as a Wee1-like kinase. The previously isolated Wee1-like kinase, Xenopus Wee1, is expressed only as maternal gene product. In contrast, Xenopus Wee2 is predominantly a zygotic gene product, while the third Wee kinase, Xenopus Myt1, is both a maternal and zygotic gene product. Concurrent with the changing levels of these Cdk inhibitory kinases, the pattern of embryonic cell division becomes asynchronous and spatially restricted in the Xenopus embryo. Interestingly, once zygotic transcription begins, Xenopus Wee2 is expressed in regions of the embryo that are devoid of mitotic cells, such as the involuting mesoderm. In contrast, Xenopus Myt1 is expressed in regions of the embryo that have high levels of proliferation, such as the developing neural tissues. The existence of multiple Wee kinases may help explain how distinct patterns of cell division arise and are regulated during development