keyword
MENU ▼
Read by QxMD icon Read
search

Directed Evolution

keyword
https://www.readbyqxmd.com/read/28346548/kinetics-of-light-induced-ordering-and-deformation-in-lc-azobenzene-containing-materials
#1
Vladimir Toshchevikov, Tatiana Petrova, Marina Saphiannikova
Azobenzene-containing smart materials are able to transform the energy of light into directional mechanical stress. We develop a theory of time-dependent light-induced ordering and deformation in azobenzene materials starting from the kinetic equations of photoisomerization. The liquid crystalline (LC) interactions between rod-like trans-isomers are taken into account. Angular selectivity of the photoisomerization known as an "angular hole burning" or the Weigert effect leads to the light-induced ordering and deformation of the azobenzene materials...
March 27, 2017: Soft Matter
https://www.readbyqxmd.com/read/28345775/quantification-of-the-position-and-depth-of-the-flexor-hallucis-longus-groove-in-euarchontans-with-implications-for-the-evolution-of-primate-positional-behavior
#2
Gabriel S Yapuncich, Erik R Seiffert, Doug M Boyer
OBJECTIVE: On the talus, the position and depth of the groove for the flexor hallucis longus tendon have been used to infer phylogenetic affinities and positional behaviors of fossil primates. This study quantifies aspects of the flexor hallucis longus groove (FHLG) to test if: (1) a lateral FHLG is a derived strepsirrhine feature, (2) a lateral FHLG reflects inverted and abducted foot postures, and (3) a deeper FHLG indicates a larger muscle. METHODS: We used linear measurements of microCT-generated models from a sample of euarchontans (n = 378 specimens, 125 species) to quantify FHLG position and depth...
March 27, 2017: American Journal of Physical Anthropology
https://www.readbyqxmd.com/read/28345481/cost-effectiveness-analysis-of-implementing-an-antimicrobial-stewardship-programme-in-critical-care-units
#3
Jesus Ruiz-Ramos, Juan Frasquet, Eva Romá, Jose Luis Poveda-Andres, Miguel Salavert-Leti, Alvaro Catellanos, Paula Ramirez
AIMS: To evaluate the cost-effectiveness of antimicrobial stewardship (AS) programme implementation focused on critical care units based on assumptions for the Spanish setting. MATERIAL AND METHODS: A decision model comparing costs and outcomes of sepsis, community-acquired pneumonia, and nosocomial infections (including catheter-related bacteremia, urinary tract infection, and ventilator-associated pneumonia) in critical care units with or without an AS was designed...
March 26, 2017: Journal of Medical Economics
https://www.readbyqxmd.com/read/28345194/decay-of-the-glycolytic-pathway-and-adaptation-to-intranuclear-parasitism-within-enterocytozoonidae-microsporidia
#4
Dominic Wiredu Boakye, Pattana Jaroenlak, Anuphap Prachumwat, Tom A Williams, Kelly S Bateman, Ornchuma Itsathitphaisarn, Kallaya Sritunyalucksana, Konrad H Paszkiewicz, Karen A Moore, Grant D Stentiford, Bryony A P Williams
Glycolysis and oxidative phosphorylation are the fundamental pathways of ATP generation in eukaryotes. Yet in microsporidia, endoparasitic fungi living at the limits of cellular streamlining, oxidative phosphorylation has been lost: energy is obtained directly from the host or, during the dispersive spore stage, via glycolysis. It was therefore surprising when the first genome from the Enterocytozoonidae - a major family of human and animal-infecting microsporidians - appeared to have lost glycolysis. Here we sequence and analyse genomes from four additional members of this family, shedding new light on their unusual biology...
March 26, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28345044/continental-igneous-rock-composition-a-major-control-of-past-global-chemical-weathering
#5
Clément P Bataille, Amy Willis, Xiao Yang, Xiao-Ming Liu
The composition of igneous rocks in the continental crust has changed throughout Earth's history. However, the impact of these compositional variations on chemical weathering, and by extension on seawater and atmosphere evolution, is largely unknown. We use the strontium isotope ratio in seawater [((87)Sr/(86)Sr)seawater] as a proxy for chemical weathering, and we test the sensitivity of ((87)Sr/(86)Sr)seawater variations to the strontium isotopic composition ((87)Sr/(86)Sr) in igneous rocks generated through time...
March 2017: Science Advances
https://www.readbyqxmd.com/read/28345024/ovad1-a-novel-potent-and-selective-chimeric-oncolytic-virus-developed-for-ovarian-cancer-by-3d-directed-evolution
#6
Irene Kuhn, Maxine Bauzon, Nicola Green, Len Seymour, Kerry Fisher, Terry Hermiston
Effective therapeutics for ovarian cancer continue to be urgently needed, particularly for chemotherapy-resistant cases. Here we present both a 3D-Matrigel culture-based expansion of our directed evolution method for generation of oncolytic virotherapies and two promising ovarian-cancer targeted oncolytic viruses, OvAd1 and OvAd2. OvAd1 was developed using Matrigel cell cultures, whereas OvAd2 was developed in parallel using traditional monolayer tissue culture methods. Both viruses are potent against a panel of platinum-resistant ovarian cancer cell lines and are attenuated on normal cells in vitro, resulting in therapeutic windows of ∼200-fold...
March 17, 2017: Molecular Therapy Oncolytics
https://www.readbyqxmd.com/read/28344912/the-topography-of-a-continental-indenter-the-interplay-between-crustal-deformation-erosion-and-base-level-changes-in-the-eastern-southern-alps
#7
J Robl, B Heberer, G Prasicek, F Neubauer, S Hergarten
The topography of the eastern Southern Alps (ESA) reflects indenter tectonics causing crustal shortening, surface uplift, and erosional response. Fluvial drainages were perturbed by Pleistocene glaciations that locally excavated alpine valleys. The Late Miocene desiccation of the Mediterranean Sea and the uplift of the northern Molasse Basin led to significant base level changes in the far field of the ESA and the Eastern Alps (EA), respectively. Among this multitude of mechanisms, the processes that dominate the current topographic evolution of the ESA and the ESA-EA drainage divide have not been identified...
January 2017: Journal of Geophysical Research. Earth Surface
https://www.readbyqxmd.com/read/28344871/description-of-the-immune-microenvironment-of-chondrosarcoma-and-contribution-to-progression
#8
François A Simard, Iseulys Richert, Alexandra Vandermoeten, Anne-Valérie Decouvelaere, Jean-Philippe Michot, Christophe Caux, Jean-Yves Blay, Aurélie Dutour
Chondrosarcoma (CHS) is a rare bone malignancy characterized by its resistance to conventional systemic and radiation therapies. Whether immunotherapy targeting immune checkpoints may be active in these tumors remains unknown. To explore the role of the immune system in this tumor, we analyzed the immune environment of chondrosarcomas both in human sample, and in a syngeneic rat model, and tested the contribution of T lymphocytes and macrophages in chondrosarcoma progression. Immunohistochemical stainings were performed on human chondrosarcoma samples and on Swarm rat chondrosarcoma (SRC) model...
2017: Oncoimmunology
https://www.readbyqxmd.com/read/28343390/high-performance-rh2p-electrocatalyst-for-efficient-water-splitting
#9
Haohong Duan, Dongguo Li, Yan Tang, Yang He, Ji Shu Fang, Rongyue Wang, Haifeng Lv, Pietro P Lopes, Arvydas P Paulikas, Haoyi Li, Scott X Mao, Chong-Min Wang, Nenad M Markovic, Jun Li, Vojislav R Stamenkovic, Yadong Li
Search for active, stable and cost-efficient electrocataltysts for hydrogen production via water splitting could make substantial impact to the energy technologies that do not rely on fossil fuels. Here we report the synthesis of rhodium phosphide electrocatalyst with low metal loading in the form of nanocubes (NCs) dispersed in high surface area carbon (Rh2P/C) by a facile solvo-thermal approach. The Rh2P/C exhibit remarkable performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) compared to Rh/C and Pt/C catalysts...
March 26, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28343268/cytogenetic-comparison-of-heteromorphic-and-homomorphic-sex-chromosomes-in-coccinia-cucurbitaceae-points-to-sex-chromosome-turnover
#10
Aretuza Sousa, Jörg Fuchs, Susanne S Renner
Our understanding of the evolution of plant sex chromosomes is increasing rapidly due to high-throughput sequencing data and phylogenetic and molecular-cytogenetic approaches that make it possible to infer the evolutionary direction and steps leading from homomorphic to heteromorphic sex chromosomes. Here, we focus on four species of Coccinia, a genus of 25 dioecious species, including Coccinia grandis, the species with the largest known plant Y chromosome. Based on a phylogeny for the genus, we selected three species close to C...
March 25, 2017: Chromosome Research
https://www.readbyqxmd.com/read/28341706/partner-abundance-controls-mutualism-stability-and-the-pace-of-morphological-change-over-geologic-time
#11
Guillaume Chomicki, Susanne S Renner
Mutualisms that involve symbioses among specialized partners may be more stable than mutualisms among generalists, and theoretical models predict that in many mutualisms, partners exert reciprocal stabilizing selection on traits directly involved in the interaction. A corollary is that mutualism breakdown should increase morphological rates of evolution. We here use the largest ant-plant clade (Hydnophytinae), with different levels of specialization for mutualistic ant symbionts, to study the ecological context of mutualism breakdown and the response of a key symbiosis-related trait, domatium entrance hole size, which filters symbionts by size...
March 24, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28339862/a-new-insight-into-the-evolution-and-functional-divergence-of-sweet-transporters-in-chinese-white-pear-pyrus-bretschneideri
#12
Jiaming Li, Mengfan Qin, Xin Qiao, Yinsheng Cheng, Xiaolong Li, Huping Zhang, Jun Wu
SWEET genes are a recently identified plant gene family that play an indispensable role in sugar efflux. However, no systematic study has been performed in pear. In this research, 18 SWEET transporters identified in pear, almost twice the number found in woodland strawberry and Japanese apricot, were divided into four clades. Conserved motifs and six exons of the SWEET transporters were found in six species. SWEET transporters contained seven transmembrane segments (TMSs) that evolved from an internal duplication of an ancestral three-TMSs unit, connected by TMS4...
March 1, 2017: Plant & Cell Physiology
https://www.readbyqxmd.com/read/28338893/site-directed-mutant-libraries-for-isolating-minimal-mutations-yielding-functional-changes
#13
Dong Hee Chung, Sarah C Potter, Ammon C Tanomrat, Krishnakumar M Ravikumar, Michael D Toney
Powerful, facile new ways to create libraries of site-directed mutants are demonstrated. These include: (1) one-pot-PCR, (2) multi-pot-PCR, and (3) split-mix-PCR. One-pot-PCR uses mutant oligonucleotides to generate megaprimers in situ, and it was used to randomly incorporate 28 mutations in a gabT gene in a single reaction. In more difficult cases, multi-pot-PCR can be employed: mutant megaprimers are synthesized individually, then combined in a single mutagenesis PCR. This method was used to incorporate 14 out of 15 mutations in a pabB gene...
March 9, 2017: Protein Engineering, Design & Selection: PEDS
https://www.readbyqxmd.com/read/28338820/evolutionary-dynamics-of-regulatory-changes-underlying-gene-expression-divergence-among-saccharomyces-species
#14
Brian P H Metzger, Patricia J Wittkopp, Joseph D Coolon
Heritable changes in gene expression are important contributors to phenotypic differences within and between species and are caused by mutations in cis-regulatory elements and trans-regulatory factors. While previous work has suggested that cis-regulatory differences preferentially accumulate with time, technical restrictions to closely related species and limited comparisons have made this observation difficult to test. To address this problem, we used allele-specific RNA-seq data from Saccharomyces species and hybrids to expand both the evolutionary timescale and number of species in which the evolution of regulatory divergence has been investigated...
February 22, 2017: Genome Biology and Evolution
https://www.readbyqxmd.com/read/28338799/novel-form-of-the-michaelis-menten-equation-that-enables-accurate-estimation-of-kcat-km-ki-with-just-two-rate-measurements-utility-in-directed-evolution
#15
Jian Lu, Yuxia Dong, Emily C Ng, Daniel L Siehl
One of applications of directed evolution is to desensitize an enzyme to an inhibitor. kcat,1/KM and KI are three dimensions that when multiplied measure an enzyme's intrinsic capacity for catalysis in the presence of an inhibitor. The ideal values for the individual dimensions depend on substrate and inhibitor concentrations under the conditions of the application. When attempting to optimize those values by directed evolution, (kcat/KM)*KI can be an informative parameter for evaluating libraries of variants, but throughput is limited...
February 22, 2017: Protein Engineering, Design & Selection: PEDS
https://www.readbyqxmd.com/read/28338698/thermally-driven-bubble-evolution-at-a-heater-wire-in-water-characterized-by-high-speed-transmission-electron-microscopy
#16
J R Vance, S J Dillon
This work investigates the early stage evolution of thermally nucleated microbubbles in water using in situ high-speed, 400 fps, transmission electron microscopy. A Pt wire Joule heater induced bubble nucleation and growth from air-saturated water at different levels of power. For all powers below Pt breakdown, the dissolved gas initiates bubble nucleation at the concave surface defects adjacent to the area of highest temperature. A combination of interfacial forces and stress relaxation drive rapid migration of the bubbles away from the nucleation site...
March 24, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28338492/the-evolution-of-current-research-impact-metrics-from-bibliometrics-to-altmetrics
#17
Joseph S Butler, I David Kaye, Arjun S Sebastian, Scott C Wagner, Patrick B Morrissey, Gregory D Schroeder, Christopher K Kepler, Alexander R Vaccaro
The prestige of publication has been based on traditional citation metrics, most commonly journal impact factor. However, the Internet has radically changed the speed, flow, and sharing of medical information. Furthermore, the explosion of social media, along with development of popular professional and scientific websites and blogs, has led to the need for alternative metrics, known as altmetrics, to quantify the wider impact of research. We explore the evolution of current research impact metrics and examine the evolving role of altmetrics in measuring the wider impact of research...
March 23, 2017: Clinical Spine Surgery
https://www.readbyqxmd.com/read/28337912/nanostructured-nickel-cobalt-titanium-alloy-grown-on-titanium-substrate-as-efficient-electrocatalysts-for-alkaline-water-electrolysis
#18
Pandian Ganesan, Sivanantham Arumugam, Sangaraju Shanmugam
One of the important challenges in alkaline water electrolysis are to utilize a bifunctional catalyst for both hydrogen evolution (HER) and oxygen evolution (OER) reactions to increase the efficiency of water splitting devices for the long durable operations. Herein, nickel-cobalt-titanium alloy directly grown on a high corrosion resistance titanium foil (NCT) by a simple, single and rapid electrochemical deposition at room temperature. The electrocatalytic activity of NCT alloy electrodes is evaluated for both HER and OER in aqueous electrolyte...
March 24, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28337898/melanin-of-the-nipple-areola-complex
#19
A Goren, M Kovacevic, T Lotti
Biological pigments or biochromes are ubiquitous in animals, plants, and simpler organisms such as fungi and bacteria. They serve a wide spectrum of functions from photosynthesis, camouflage, mimicry, photo protection from the environment to attracting mates. The human female nipple areola complex (NAC) is a highly-pigmented area. Currently, the prevailing theory as to the evolution of the pigmented human NAC is based on infant recognition of breast feeding latching zone; however, due to the protruding shape of the nipple and surrounding breast, the authors of this letter believe that the evolutionary advantage of the pigmented NAC has a direct physiological function, namely the initiation of involution at the end of the infant lactation period...
January 2017: Journal of Biological Regulators and Homeostatic Agents
https://www.readbyqxmd.com/read/28337138/motor-skill-learning-in-an-insect-inspired-neuro-computational-control-system
#20
Eleonora Arena, Paolo Arena, Roland Strauss, Luca Patané
In nature, insects show impressive adaptation and learning capabilities. The proposed computational model takes inspiration from specific structures of the insect brain: after proposing key hypotheses on the direct involvement of the mushroom bodies (MBs) and on their neural organization, we developed a new architecture for motor learning to be applied in insect-like walking robots. The proposed model is a nonlinear control system based on spiking neurons. MBs are modeled as a nonlinear recurrent spiking neural network (SNN) with novel characteristics, able to memorize time evolutions of key parameters of the neural motor controller, so that existing motor primitives can be improved...
2017: Frontiers in Neurorobotics
keyword
keyword
25222
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"