keyword
MENU ▼
Read by QxMD icon Read
search

exo

keyword
https://www.readbyqxmd.com/read/28444826/indium-iii-catalyzed-aza-conia-ene-reaction-for-the-synthesis-of-indolizines
#1
Karl Anker Jørgensen, Marta Meazza, Lars Astrup Leth, Jeremy David Erickson
A novel indium(III)-catalyzed reaction for the synthesis of a series of indolizine scaffolds has been developed. This methodology is highly efficient, allowing a low catalyst loading of 2 mol% (down to 0.5 mol%) and rendering the products in high yields through a 5-exo-dig aza-Conia-ene reaction. Further-more, the possibility of incorporating an electrophile to the generated pyrrolidine-ring in a one-pot synergistic fashion is demonstrated. Finally, based on experimental observations, a mechanism proposal is outlined...
April 26, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28431748/a-benchtop-biorobotic-platform-for-in-vitro-observation-of-muscle-tendon-dynamics-with-parallel-mechanical-assistance-from-an-elastic-exoskeleton
#2
Benjamin D Robertson, Siddarth Vadakkeveedu, Gregory S Sawicki
We present a novel biorobotic framework comprised of a biological muscle-tendon unit (MTU) mechanically coupled to a feedback controlled robotic environment simulation that mimics in vivo inertial/gravitational loading and mechanical assistance from a parallel elastic exoskeleton. Using this system, we applied select combinations of biological muscle activation (modulated with rate-coded direct neural stimulation) and parallel elastic assistance (applied via closed-loop mechanical environment simulation) hypothesized to mimic human behavior based on previously published modeling studies...
March 21, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28429132/development-of-a-real-time-recombinase-polymerase-amplification-assay-for-rapid-and-sensitive-detection-of-porcine-circovirus-2
#3
Jianchang Wang, Jinfeng Wang, Libing Liu, Wanzhe Yuan
Porcine diseases associated with porcine circovirus 2 (PCV-2) infection have resulted in significant economic losses worldwide. A real-time recombinase polymerase amplification (RPA) assay was developed to detect PCV-2 using primers and an exo probe specific for the ORF2 gene. The reaction process can be completed in 20 min at 38 °C. The assay only detects PCV-2, as there was no cross-reaction with other pathogens important in pigs. Using the PCV-2 genomic DNA as template, the analytical sensitivity of the real-time RPA was 103 copies...
April 20, 2017: Archives of Virology
https://www.readbyqxmd.com/read/28427347/comparative-transcriptomics-of-mountain-pine-beetle-pheromone-biosynthetic-tissues-and-functional-analysis-of-cyp6de3
#4
J A Nadeau, J Petereit, R L Tillett, K Jung, M Fotoohi, M MacLean, S Young, K Schlauch, G J Blomquist, C Tittiger
BACKGROUND: The mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) is a highly destructive pest of pine forests in western North America. During flight to a new host tree and initiation of feeding, mountain pine beetles release aggregation pheromones. The biosynthetic pathways of these pheromones are sex-specific and localized in the midgut and fat body, but the enzymes involved have not all been identified or characterized. RESULTS: We used a comparative RNA-Seq analysis between fed and unfed male and female MPB midguts and fat bodies to identify candidate genes involved in pheromone biosynthesis...
April 20, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28427305/neuromechanical-adaptations-during-a-robotic-powered-exoskeleton-assisted-walking-session
#5
Arvind Ramanujam, Christopher M Cirnigliaro, Erica Garbarini, Pierre Asselin, Rakesh Pilkar, Gail F Forrest
OBJECTIVE: To evaluate gait parameters and neuromuscular profiles of exoskeleton-assisted walking under Max Assist condition during a single-session for; (i) able bodied (AB) individuals walking assisted with (EXO) and without (non-EXO) a powered exoskeleton, (ii) non-ambulatory SCI individuals walking assisted with a powered exoskeleton. DESIGN: Single-session. SETTING: Motion analysis laboratory. PARTICIPANTS: Four AB individuals and four individuals with SCI...
April 20, 2017: Journal of Spinal Cord Medicine
https://www.readbyqxmd.com/read/28425549/nicotinamide-adenine-dinucleotide-detection-based-on-silver-nanoclusters-stabilized-by-a-dumbbell-shaped-probe
#6
Hong-Ya Wang, Jin-Liang Ma, Bin-Cheng Yin, Bang-Ce Ye
We have developed a novel method for detecting nicotinamide adenine dinucleotide (NAD(+)) based on fluorescent silver nanoclusters (AgNCs) stabilized by a dumbbell-shaped DNA template containing two cytosine-loops joined in a dsDNA stem. The design involves two types of components: a dumbbell-shaped DNA template and three enzymes. In the presence of NAD(+) as a cofactor, Escherichia coli DNA ligase (E.coli DNA ligase) catalyzes template ligation to generate a sealed (no terminal nucleotides) dumbbell-shaped structure, preventing digestion by exonuclease III (Exo III) and exonuclease I (Exo I)...
April 20, 2017: Analyst
https://www.readbyqxmd.com/read/28421898/targeting-the-nuclear-rna-exosome-poly-a-binding-proteins-enter-the-stage
#7
Nicola Meola, Torben Heick Jensen
Centrally positioned in nuclear RNA metabolism, the exosome deals with virtually all transcript types. This 3'-5' exo- and endo-nucleolytic degradation machine is guided to its RNA targets by adaptor proteins that enable substrate recognition. Recently, the discovery of the 'Poly(A) tail exosome targeting (PAXT)' connection as an exosome adaptor to human nuclear polyadenylated transcripts has relighted the interest of poly(A) binding proteins (PABPs) in both RNA productive and destructive processes.
April 19, 2017: RNA Biology
https://www.readbyqxmd.com/read/28419521/cytokinetic-abscission-phosphoinositides-and-escrts-direct-the-final-cut
#8
Federico Gulluni, Miriam Martini, Emilio Hirsch
Cytokinetic abscission involves the fine and regulated recruitment of membrane remodeling proteins that participate in the abscission of the intracellular bridge that connects the two dividing cells. This essential process is mediated by the concomitant activity of the endosomal sorting complex required for transport (ESCRT) and the vesicular trafficking directed to the midbody. Phosphoinositides (PtdIns), produced at plasma membrane and endosomes, act as molecular intermediates by recruiting effector proteins involved in multiple cellular processes, such as intracellular signalling, endo- and exo-cytosis and membrane remodelling events...
April 17, 2017: Journal of Cellular Biochemistry
https://www.readbyqxmd.com/read/28413018/plaa-mutations-cause-a-lethal-infantile-epileptic-encephalopathy-by-disrupting-ubiquitin-mediated-endolysosomal-degradation-of-synaptic-proteins
#9
Emma A Hall, Michael S Nahorski, Lyndsay M Murray, Ranad Shaheen, Emma Perkins, Kosala N Dissanayake, Yosua Kristaryanto, Ross A Jones, Julie Vogt, Manon Rivagorda, Mark T Handley, Girish R Mali, Tooba Quidwai, Dinesh C Soares, Margaret A Keighren, Lisa McKie, Richard L Mort, Noor Gammoh, Amaya Garcia-Munoz, Tracey Davey, Matthieu Vermeren, Diana Walsh, Peter Budd, Irene A Aligianis, Eissa Faqeih, Alan J Quigley, Ian J Jackson, Yogesh Kulathu, Mandy Jackson, Richard R Ribchester, Alex von Kriegsheim, Fowzan S Alkuraya, C Geoffrey Woods, Eamonn R Maher, Pleasantine Mill
During neurotransmission, synaptic vesicles undergo multiple rounds of exo-endocytosis, involving recycling and/or degradation of synaptic proteins. While ubiquitin signaling at synapses is essential for neural function, it has been assumed that synaptic proteostasis requires the ubiquitin-proteasome system (UPS). We demonstrate here that turnover of synaptic membrane proteins via the endolysosomal pathway is essential for synaptic function. In both human and mouse, hypomorphic mutations in the ubiquitin adaptor protein PLAA cause an infantile-lethal neurodysfunction syndrome with seizures...
April 10, 2017: American Journal of Human Genetics
https://www.readbyqxmd.com/read/28411826/a-novel-fluorescent-biosensor-for-adenosine-triphosphate-detection-based-on-the-polydopamine-nanospheres-integrating-with-enzymatic-recycling-amplification
#10
Xiaoting Ji, Bingqing Yi, Yujuan Xu, Yanan Zhao, Hua Zhong, Caifeng Ding
Based on the protective performance of polydopamine nanospheres (PDANSs) for DNA against nuclease digestion and the specific recognition characteristic of aptamer, we have developed an enzymatic recycling signal amplification method for highly sensitive and selective detection of adenosine triphosphate (ATP). Fluorescence measurements were carried out to verify the DNA polymerase and exonuclease III (Exo III) assisted target recycling process and fluorescence signal amplification. In the absence of the ATP, initially, the signal DNA-PDANSs complex was in the "off" state due to the efficient fluorescence quenching of 6-carboxyfluorescein (FAM) adjacent to the surface of PDANSs...
July 1, 2017: Talanta
https://www.readbyqxmd.com/read/28408484/joint-features-and-complementarities-of-tspan8-and-cd151-revealed-in-knockdown-and-knockout-models
#11
REVIEW
Shijing Yue, Kun Zhao, Ulrike Erb, Sanyukta Rana, Margot Zöller
Tetraspanins are highly conserved 4-transmembrane proteins which form molecular clusters with a large variety of transmembrane and cytosolic proteins. By these associations tetraspanins are engaged in a multitude of biological processes. Furthermore, tetraspanin complexes are located in specialized microdomains, called tetraspanin-enriched microdomains (TEMs). TEMs provide a signaling platform and are poised for invagination and vesicle formation. These vesicles can be released as exosomes (Exo) and are important in cell contact-independent intercellular communication...
April 15, 2017: Biochemical Society Transactions
https://www.readbyqxmd.com/read/28407783/exosomal-transfer-of-tumor-associated-macrophage-derived-mir-21-confers-cisplatin-resistance-in-gastric-cancer-cells
#12
Peiming Zheng, Lei Chen, Xiangliang Yuan, Qin Luo, Yi Liu, Guohua Xie, Yanhui Ma, Lisong Shen
BACKGROUND: Cisplatin-based chemotherapy is frequently used to treat advanced gastric cancer (GC). However, the resistance often occurs with the mechanisms being not well understood. Recently, emerging evidence indicates that tumor-associated macrophages (TAMs) play an important role in chemoresistance of cancer. As the important mediators in intercellular communications, exosomes secreted by host cells mediate the exchange of genetic materials and proteins to be involved in tumor aggressiveness...
April 13, 2017: Journal of Experimental & Clinical Cancer Research: CR
https://www.readbyqxmd.com/read/28398840/the-ntry-ntrx-system-of-sinorhizobium-meliloti-gr4-regulates-motility-eps-i-production-and-nitrogen-metabolism-but-is-dispensable-for-symbiotic-nitrogen-fixation
#13
Nieves Calatrava-Morales, Joaquina Nogales, Kinia Ameztoy, Bart van Steenbergen, María José Soto
Sinorhizobium meliloti can translocate over surfaces. However, little is known about the regulatory mechanisms that control this trait and its relevance for establishing symbiosis with alfalfa plants. To gain insights into this field, we isolated Tn5 mutants of S. meliloti GR4 with impaired surface motility. In mutant strain GRS577, the transposon interrupted the ntrY gene encoding the sensor kinase of the NtrY/NtrX two-component regulatory system. GRS577 is impaired in flagella synthesis, and overproduces succinoglycan which is responsible for increased biofilm formation...
April 11, 2017: Molecular Plant-microbe Interactions: MPMI
https://www.readbyqxmd.com/read/28398443/changing-the-path-of-least-resistance-or-access-to-endo-dig-products-via-a-sequence-of-three-exo-trig-transition-states-electronic-effects-in-homoallyic-ring-expansion-cascades-of-alkenyl-isonitriles
#14
Gabriel Dos Passos Gomes, Christopher J Evoniuk, Michelle Ly, Igor V Alabugin
Chemoselective addition of radicals to isonitriles can be harnessed for initiating reaction cascades designed to overcome the stereoelectronic restrictions on homoallylic ring expansion in alkyne reactions and to develop a new general route for the preparation of N-heteroaromatics. This method utilizes alkenes as synthetic equivalents of alkynes by coupling homoallylic ring expansion to yield the formal "6-endo" products with aromatization via stereoelectronically assisted C-C bond scission. Detailed computational analysis of the individual steps of the homoallylic expansion sequence maps effects of substituents and structural constraints on this multi-step potential energy surface...
April 11, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28396546/structural-insights-into-hiv-reverse-transcriptase-mutations-q151m-and-q151m-complex-that-confer-multi-nucleoside-drug-resistance
#15
Kalyan Das, Sergio E Martinez, Eddy Arnold
HIV-1 reverse transcriptase (RT) is targeted by multiple drugs. RT mutations emerge that confer resistance to nucleoside RT inhibitors (NRTIs) in clinical use. Q151M, and four associated mutations A62V, V75I, F77L, and F116Y were detected in patients failing therapies to dideoxynucleosides (didanosine, ddI; zalcitabine, ddC) and/or zidovudine (AZT). The cluster of the five mutations is referred to as the Q151M complex (Q151Mc), and an RT or virus containing Q151Mc exhibits resistance to multiple NRTIs. To understand the structural basis for Q151M and Q151Mc resistance, we have systematically determined crystal structures of wild-type RT/dsDNA/dATP (I), wild-type RT/dsDNA/ddATP (II), Q151M RT/dsDNA/dATP (III), Q151Mc RT/dsDNA/dATP (IV), and Q151Mc RT/dsDNA/ddATP (V) ternary complexes...
April 10, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28393464/exo-and-surface-proteomes-of-the-probiotic-bacterium-lactobacillus-acidophilus-ncfm
#16
Hasan Ufuk Celebioglu, Birte Svensson
Lactobacillus acidophilus NCFM is a well-known probiotic bacterium extensively studied for its beneficial health effects. Exoproteome (proteins exported into culture medium) and surface proteome (proteins attached to S-layer) of this probiotic were identified by using 2DE followed by MALDI TOF MS to find proteins potentially involved in bacteria-host interactions. The exo- and surface proteomes included 43 and 39 different proteins from 72 and 49 successfully identified spots, respectively. Twenty-two proteins were shared between the two proteomes; both contained the major surface layer protein that participates in host interaction as well as several well-known and putative moonlighting proteins...
April 9, 2017: Proteomics
https://www.readbyqxmd.com/read/28389394/kinetically-accessible-yield-kay-for-redirection-of-metabolism-to-produce-exo-metabolites
#17
Jimmy G Lafontaine Rivera, Matthew K Theisen, Po-Wei Chen, James C Liao
The product formation yield (product formed per unit substrate consumed) is often the most important performance indicator in metabolic engineering. Until now, the actual yield cannot be predicted, but it can be bounded by its maximum theoretical value. The maximum theoretical yield is calculated by considering the stoichiometry of the pathways and cofactor regeneration involved. Here we found that in many cases, dynamic stability becomes an issue when excessive pathway flux is drawn to a product. This constraint reduces the yield and renders the maximal theoretical yield too loose to be predictive...
April 5, 2017: Metabolic Engineering
https://www.readbyqxmd.com/read/28388522/hydrogen-peroxide-activated-quinone-methide-precursors-with-enhanced-dna-cross-linking-capability-and-cytotoxicity-towards-cancer-cells
#18
Yibin Wang, Heli Fan, Kumudha Balakrishnan, Zechao Lin, Sheng Cao, Wenbing Chen, Yukai Fan, Quibria A Guthrie, Huabing Sun, Kelly A Teske, Varsha Gandhi, Leggy A Arnold, Xiaohua Peng
Quinone methide (QM) formation induced by endogenously generated H2O2 is attractive for biological and biomedical applications. To overcome current limitations due to low biological activity of H2O2-activated QM precursors, we are introducing herein several new arylboronates with electron donating substituents at different positions of benzene ring and/or different neutral leaving groups. The reaction rate of the arylboronate esters with H2O2 and subsequent bisquinone methides formation and DNA cross-linking was accelerated with the application of Br as a leaving group instead of acetoxy groups...
March 24, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28386471/characterization-of-virulence-potential-of-pseudomonas-aeruginosa-isolated-from-bovine-meat-fresh-fish-and-smoked-fish
#19
Comoé Koffi Donatien Benie, Adjéhi Dadié, Nathalie Guessennd, Nadège Ahou N'gbesso-Kouadio, N'zebo Désiré Kouame, David Coulibaly N'golo, Solange Aka, Etienne Dako, Koffi Marcellin Dje, Mireille Dosso
Pseudomonas aeruginosa owns a variability of virulence factors. These factors can increase bacterial pathogenicity and infection severity. Despite the importance of knowledge about them, these factors are not more characterized at level of strains derived from local food products. This study aimed to characterize the virulence potential of P. aeruginosa isolated from various animal products. Several structural and virulence genes of P. aeruginosa including lasB, exoS, algD, plcH, pilB, exoU, and nan1 were detected by polymerase chain reaction (PCR) on 204 strains of P...
March 2017: European Journal of Microbiology & Immunology
https://www.readbyqxmd.com/read/28384222/functional-studies-of-e-faecalis-rnase-j2-and-its-role-in-virulence-and-fitness
#20
Peng Gao, Kenneth L Pinkston, Agathe Bourgogne, Barbara E Murray, Ambro van Hoof, Barrett R Harvey
Post-transcriptional control provides bacterial pathogens a method by which they can rapidly adapt to environmental change. Dual exo- and endonucleolytic activities of RNase J enzymes contribute to Gram-positive RNA processing and decay. First discovered in Bacillus subtilis, RNase J1 plays a key role in mRNA maturation and degradation, while the function of the paralogue RNase J2 is largely unknown. Previously, we discovered that deletion of the Enterococcus faecalis rnjB gene significantly attenuates expression of a major virulence factor involved in enterococcal pathogenesis, the Ebp pili...
2017: PloS One
keyword
keyword
49874
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"