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https://www.readbyqxmd.com/read/29150015/the-flotation-and-adsorption-of-mixed-collectors-on-oxide-and-silicate-minerals
#1
REVIEW
Longhua Xu, Jia Tian, Houqin Wu, Zhongyuan Lu, Wei Sun, Yuehua Hu
The analysis of flotation and adsorption of mixed collectors on oxide and silicate minerals is of great importance for both industrial applications and theoretical research. Over the past years, significant progress has been achieved in understanding the adsorption of single collectors in micelles as well as at interfaces. By contrast, the self-assembly of mixed collectors at liquid/air and solid/liquid interfaces remains a developing area as a result of the complexity of the mixed systems involved and the limited availability of suitable analytical techniques...
November 11, 2017: Advances in Colloid and Interface Science
https://www.readbyqxmd.com/read/29149539/dynamic-cross-exchange-in-halophosphonium-species-first-direct-observation-of-stereochemical-inversion-in-the-course-of-an-sn2-process
#2
Kirill Nikitin, Elizabeth V Jennings, Sulaiman Al Sulaimi, Yannick Ortin, Declan G Gilheany
The complex fluxional interconversions between, otherwise very similar, phosphonium bromides and chlorides R3PX+X- (R = Alk, Ar, X = Cl or Br) was studied by NMR techniques. Their energy barriers are typically ca. 11 kcal/mol but rise rapidly as bulky groups are attached to phosphorus, revealing the importance of steric factors. In contrast, electronic effects, as measured by Hammett analysis, are modest (rho 1.46) but still clearly indicate negative charge flow towards phosphorus in the transition state. Most significantly, detailed analysis of the exchange pathways unequivocally, and for the first time in any such process, shows that nucleophilic attack of the nucleophilic anion on the tetrahedral centre results in inversion of configuration...
November 17, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29149479/cripsr-cas-expands-dynamic-range-of-gene-expression-from-t7rnap-promoters
#3
Sean R McCutcheon, Kwan Lun Chiu, Daniel D Lewis, Cheemeng Tan
BACKGROUND: Reducing leaky gene expression is critical for improving protein yield of recombinant bacteria and stability of engineered cellular circuits in synthetic biology. Leaky gene expression occurs when a genetic promoter is not fully repressed, leading to unintended protein synthesis in the absence of stimuli. Existing work has devised specific molecular strategies for reducing leaky gene expression of each promoter. Main Method and Results: In contrast, we describe a repurposed, modular CRISPRi system that attenuates leaky gene expression using a series of single-guide RNAs targeting the PT7/LacO1 ...
November 17, 2017: Biotechnology Journal
https://www.readbyqxmd.com/read/29147679/dense-fluidized-granular-media-in-microgravity
#4
Philip Born, Johannes Schmitz, Matthias Sperl
Handling and transport of granular media are inevitably governed by the settling of particles. Settling into a dense state is one of the defining characteristics of granular media, among dissipation and absence of thermal agitation. Hence, settling complicates the adaptation of microscopic theories from atomic, molecular, or colloidal media to granular media. It is desirable to provide experiments in which selectively one of the granular characteristics is tuned to test suitable adaptation of a theory. Here we show that gas fluidization of granular media in microgravity is a suitable approach to achieve steady states closer to thermally agitated systems free of settling...
2017: NPJ Microgravity
https://www.readbyqxmd.com/read/29146919/nucleosome-acidic-patch-targeting-binuclear-ruthenium-compounds-induce-aberrant-chromatin-condensation
#5
Gabriela E Davey, Zenita Adhireksan, Zhujun Ma, Tina Riedel, Deepti Sharma, Sivaraman Padavattan, Daniela Rhodes, Alexander Ludwig, Sara Sandin, Benjamin S Murray, Paul J Dyson, Curt A Davey
The 'acidic patch' is a highly electronegative cleft on the histone H2A-H2B dimer in the nucleosome. It is a fundamental motif for protein binding and chromatin dynamics, but the cellular impact of targeting this potentially therapeutic site with exogenous molecules remains unclear. Here, we characterize a family of binuclear ruthenium compounds that selectively target the nucleosome acidic patch, generating intra-nucleosomal H2A-H2B cross-links as well as inter-nucleosomal cross-links. In contrast to cisplatin or the progenitor RAPTA-C anticancer drugs, the binuclear agents neither arrest specific cell cycle phases nor elicit DNA damage response, but rather induce an irreversible, anomalous state of condensed chromatin that ultimately results in apoptosis...
November 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/29146716/dynamic-contrast-enhanced-mri-derived-intracellular-water-lifetime-%C3%AF-i-a-prognostic-marker-for-patients-with-head-and-neck-squamous-cell-carcinomas
#6
S Chawla, L A Loevner, S G Kim, W-T Hwang, S Wang, G Verma, S Mohan, V LiVolsi, H Quon, H Poptani
BACKGROUND AND PURPOSE: Shutter-speed model analysis of dynamic contrast-enhanced MR imaging allows estimation of mean intracellular water molecule lifetime (a measure of cellular energy metabolism) and volume transfer constant (a measure of hemodynamics). The purpose of this study was to investigate the prognostic utility of pretreatment mean intracellular water molecule lifetime and volume transfer constant in predicting overall survival in patients with squamous cell carcinomas of the head and neck and to stratify p16-positive patients based upon survival outcome...
November 16, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/29146145/adars-and-editing-the-role-of-a-to-i-rna-modification-in-cancer-progression
#7
REVIEW
Kajsa Fritzell, Lidi Xu, Jens Lagergren, Marie Öhman
Cancer arises when pathways that control cell functions such as proliferation and migration are dysregulated to such an extent that cells start to divide uncontrollably and eventually spread throughout the body, ultimately endangering the survival of an affected individual. It is well established that somatic mutations are important in cancer initiation and progression as well as in creation of tumor diversity. Now also modifications of the transcriptome are emerging as a significant force during the transition from normal cell to malignant tumor...
November 13, 2017: Seminars in Cell & Developmental Biology
https://www.readbyqxmd.com/read/29145891/the-inuit-gut-microbiome-is-dynamic-over-time-and-shaped-by-traditional-foods
#8
Geneviève Dubois, Catherine Girard, François-Joseph Lapointe, B Jesse Shapiro
BACKGROUND: The human gut microbiome represents a diverse microbial community that varies across individuals and populations, and is influenced by factors such as host genetics and lifestyle. Diet is a major force shaping the gut microbiome, and the effects of dietary choices on microbiome composition are well documented. However, it remains poorly known how natural temporal variation in diet can affect the microbiome. The traditional Inuit diet is primarily based on animal products, which are thought to vary seasonally according to prey availability...
November 16, 2017: Microbiome
https://www.readbyqxmd.com/read/29145469/development-of-visual-cortical-function-in-infant-macaques-a-bold-fmri-study
#9
Tom J Van Grootel, Alan Meeson, Matthias H J Munk, Zoe Kourtzi, J Anthony Movshon, Nikos K Logothetis, Lynne Kiorpes
Functional brain development is not well understood. In the visual system, neurophysiological studies in nonhuman primates show quite mature neuronal properties near birth although visual function is itself quite immature and continues to develop over many months or years after birth. Our goal was to assess the relative development of two main visual processing streams, dorsal and ventral, using BOLD fMRI in an attempt to understand the global mechanisms that support the maturation of visual behavior. Seven infant macaque monkeys (Macaca mulatta) were repeatedly scanned, while anesthetized, over an age range of 102 to 1431 days...
2017: PloS One
https://www.readbyqxmd.com/read/29144730/cancer-protrusions-on-a-tightrope-nanofiber-curvature-contrast-quantitates-single-protrusion-dynamics
#10
Brian Koons, Puja Sharma, Zhou Ye, Apratim Mukherjee, Meng Horng Lee, Denis Wirtz, Bahareh Behkam, Amrinder Singh Nain
Cell migration is studied with the traditional focus on protrusion driven cell body displacement, while less is known on morphodynamics of individual protrusions themselves, especially in fibrous environments mimicking extracellular matrix. Here, using suspended fibers, we report integrative and multiscale abilities to study protrusive behavior independent of cell body migration. By manipulating the diameter of fibers in orthogonal directions, we constrain cell migration along large diameter (2 µm) base fibers, while solely allowing cells to sense, initiate, and mature protrusions on orthogonally deposited high curvature-low diameter (~100, 200 and 600 nm) protrusive fibers and low-curvature (~300 and 600 nm width) protrusive flat ribbons...
November 16, 2017: ACS Nano
https://www.readbyqxmd.com/read/29144161/use-of-patient-outcome-endpoints-to-identify-the-best-functional-ct-imaging-parameters-in-metastatic-renal-cell-carcinoma-patients
#11
Jill Rachel Mains, Frede Donskov, Erik Morre Petersen, Hans Henrik Torp Madsen, Jesper Thygesen, Kennet Thorup, Finn Rasmussen
OBJECTIVE: To use the patient outcome endpoints overall survival and progression-free survival to evaluate functional parameters derived from dynamic contrast-enhanced computed tomography (DCE-CT). METHODS: 69 patients with metastatic renal cell carcinoma (mRCC) had DCE-CT scans at baseline and after 5 and 10 weeks of treatment. Blood volume, blood flow and standardized perfusion values were calculated using deconvolution (BVdeconv, BFdeconv and SPVdeconv), blood flow and standardized perfusion values using maximum slope (BFmax and SPVmax), and blood volume and permeability surface area product using the Patlak model (BVpatlak and PS)...
November 16, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/29144072/relapse-and-cytogenetic-evolution-in-myeloid-neoplasms
#12
Natalie Ertz-Archambault, Katalin Kelemen
Based on the current WHO Classification of Myeloid Neoplasms, cytogenetic findings play a central role in the diagnostic classification of the myeloid malignancies. Cytogenetic abnormalities detected at primary diagnosis may change over time. Karyotype changes can be characterized as cytogenetic evolution, cytogenetic regression or a combination of both. While the exact mechanism of cytogenetic evolution is not completely understood, the process of cytogenetic evolution is not random, but follows different, and often disease-specific patterns during progression and relapse of myeloid neoplasms...
December 2017: Panminerva Medica
https://www.readbyqxmd.com/read/29143261/river-sediment-metal-and-nutrient-variations-along-an-urban-agriculture-gradient-in-an-arid-austral-landscape-implications-for-environmental-health
#13
Tatenda Dalu, Ryan J Wasserman, Qihang Wu, William P Froneman, Olaf L F Weyl
The effect of metals on environmental health is well documented and monitoring these and other pollutants is considered an important part of environmental management. Developing countries are yet to fully appreciate the direct impacts of pollution on aquatic ecosystems and as such, information on pollution dynamics is scant. Here, we assessed the temporal and spatial dynamics of stream sediment metal and nutrient concentrations using contaminant indices (e.g. enrichment factors, pollution load and toxic risk indices) in an arid temperate environment over the wet and dry seasons...
November 15, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29143200/structural-and-perfusion-magnetic-resonance-imaging-of-the-lung-in-cystic-fibrosis
#14
Christina Amaxopoulou, Ralph Gnannt, Kai Higashigaito, Andreas Jung, Christian J Kellenberger
BACKGROUND: Because of its absence of ionising radiation and possibility for obtaining functional information, MRI is promising for assessing lung disease in children who require repetitive imaging for long-term follow-up. OBJECTIVE: To describe MRI findings in children with cystic fibrosis and evaluate semi-quantitative dynamic contrast-enhanced lung perfusion. MATERIALS AND METHODS: We retrospectively compared lung MRI in 25 children and young adults with cystic fibrosis (median age 3...
November 15, 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/29143112/assessment-of-the-zonal-variation-of-perfusion-parameters-in-the-femoral-head-a-3-t-dynamic-contrast-enhanced-mri-pilot-study
#15
Jean-François Budzik, Guillaume Lefebvre, Hélène Behal, Sébastien Verclytte, Pierre Hardouin, Pedro Teixeira, Anne Cotten
OBJECTIVE: The objective was to describe MR perfusion characteristics of the femoral head, with a focus on the subchondral bone. MATERIALS AND METHODS: This prospective monocentric study was approved by our local Ethics Committee. Written informed consent was obtained from all subjects. Dynamic contrast-enhanced MRI of the right hip was performed in 59 adults with suspected spondyloarthritis (32 women, 28 men). Mean age was 37.5 (±12.5) years. Regions of interest were drawn in the femoral head epiphysis, in the subchondral areas the most exposed to mechanical load (superolateral, anterosuperior, and posterior zones) and in areas less exposed to mechanical load (inferior subchondral zone and center of the femoral head)...
November 15, 2017: Skeletal Radiology
https://www.readbyqxmd.com/read/29142223/active-diffusion-and-advection-in-drosophila-oocytes-result-from-the-interplay-of-actin-and-microtubules
#16
Maik Drechsler, Fabio Giavazzi, Roberto Cerbino, Isabel M Palacios
Transport in cells occurs via a delicate interplay of passive and active processes, including diffusion, directed transport and advection. Despite progress in super-resolution microscopy, discriminating and quantifying these processes is a challenge, requiring tracking of rapidly moving, sub-diffraction objects in a crowded, noisy environment. Here we use differential dynamic microscopy with different contrast mechanisms to provide a thorough characterization of the dynamics in the Drosophila oocyte. We study the movement of vesicles and the elusive motion of a cytoplasmic F-actin mesh, a known regulator of cytoplasmic flows...
November 15, 2017: Nature Communications
https://www.readbyqxmd.com/read/29142117/long-necks-enhance-and-constrain-foraging-capacity-in-aquatic-vertebrates
#17
Rory P Wilson, Agustina Gómez-Laich, Juan-Emilio Sala, Giacomo Dell'Omo, Mark D Holton, Flavio Quintana
Highly specialized diving birds display substantial dichotomy in neck length with, for example, cormorants and anhingas having extreme necks, while penguins and auks have minimized necks. We attached acceleration loggers to Imperial cormorants Phalacrocorax atriceps and Magellanic penguins Spheniscus magellanicus, both foraging in waters over the Patagonian Shelf, to examine the difference in movement between their respective heads and bodies in an attempt to explain this dichotomy. The penguins had head and body attitudes and movements that broadly concurred throughout all phases of their dives...
November 29, 2017: Proceedings. Biological Sciences
https://www.readbyqxmd.com/read/29142011/effect-of-distinct-lifestyle-interventions-on-mobilization-of-fat-storage-pools-the-central-mri-randomized-controlled-trial
#18
Yftach Gepner, Ilan Shelef, Dan Schwarzfuchs, Hila Zelicha, Lilac Tene, Anat Yaskolka Meir, Gal Tsaban, Noa Cohen, Nitzan Bril, Michal Rein, Dana Serfaty, Shira Kenigsbuch, Oded Komy, Arik Wolak, Yoash Chassidim, Rachel Golan, Hilla Avni-Hassid, Avital Bilitzky, Benjamin Sarusi, Eyal Goshen, Elad Shemesh, Yaakov Henkin, Michael Stumvoll, Matthias Blüher, Joachim Thiery, Uta Ceglarek, Assaf Rudich, Meir J Stampfer, Iris Shai
Background -We aimed to assess whether distinct lifestyle strategies can differentially affect specific body adipose depots. Methods -We performed an eighteen-month randomized controlled trial among 278 sedentary adults with abdominal obesity (75%) or dyslipidemia in an isolated workplace with a monitored provided lunch. Participants were randomized to iso-caloric low-fat (LF) or Mediterranean/low-carbohydrate (MED/LC) diet+28g walnuts/day with/without added moderate physical activity (PA;80% aerobic; supervised/free gym membership)...
November 15, 2017: Circulation
https://www.readbyqxmd.com/read/29141958/dna-methylation-defines-regional-identity-of-human-intestinal-epithelial-organoids-and-undergoes-dynamic-changes-during-development
#19
Judith Kraiczy, Komal M Nayak, Kate J Howell, Alexander Ross, Jessica Forbester, Camilla Salvestrini, Roxana Mustata, Sally Perkins, Amanda Andersson-Rolf, Esther Leenen, Anke Liebert, Ludovic Vallier, Philip C Rosenstiel, Oliver Stegle, Gordon Dougan, Robert Heuschkel, Bon-Kyoung Koo, Matthias Zilbauer
OBJECTIVE: Human intestinal epithelial organoids (IEOs) are increasingly being recognised as a highly promising translational research tool. However, our understanding of their epigenetic molecular characteristics and behaviour in culture remains limited. DESIGN: We performed genome-wide DNA methylation and transcriptomic profiling of human IEOs derived from paediatric/adult and fetal small and large bowel as well as matching purified human gut epithelium. Furthermore, organoids were subjected to in vitro differentiation and genome editing using CRISPR/Cas9 technology...
November 15, 2017: Gut
https://www.readbyqxmd.com/read/29141002/correlates-of-decisional-dynamics-in-the-dorsal-anterior-cingulate-cortex
#20
Habiba Azab, Benjamin Y Hayden
We hypothesized that during binary economic choice, decision makers use the first option they attend as a default to which they compare the second. To test this idea, we recorded activity of neurons in the dorsal anterior cingulate cortex (dACC) of macaques choosing between gambles presented asynchronously. We find that ensemble encoding of the value of the first offer includes both choice-dependent and choice-independent aspects, as if reflecting a partial decision. That is, its responses are neither entirely pre- nor post-decisional...
November 15, 2017: PLoS Biology
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