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https://www.readbyqxmd.com/read/29691368/a-novel-sigb-q225p-mutation-in-staphylococcus-aureus-retains-virulence-but-promotes-biofilm-formation
#1
Hui Liu, Weilong Shang, Zhen Hu, Ying Zheng, Jizhen Yuan, Qiwen Hu, Huagang Peng, Xinyu Cai, Li Tan, Shu Li, Junmin Zhu, Ming Li, Xiaomei Hu, Renjie Zhou, Xiancai Rao, Yi Yang
Staphylococcus aureus is an important pathogen that produces abundant virulence factors, which cause various diseases that burden human health worldwide. The stress response regulon called sigma factor B (SigB) is a well-characterized global regulator that is involved in the regulation of S. aureus virulence, pigmentation, and biofilm formation. However, the regulatory network upon SigB in S. aureus is incompletely described. Here, we identified a novel substitution mutation, SigB(Q225P), which contributed the nonpigmented phenotype of S...
April 25, 2018: Emerging Microbes & Infections
https://www.readbyqxmd.com/read/29690633/on-the-phase-separation-in-n-type-thermoelectric-half-heusler-materials
#2
Michael Schwall, Benjamin Balke
Half-Heusler compounds have been in focus as potential materials for thermoelectric energy conversion in the mid-temperature range, e.g., as in automotive or industrial waste heat recovery, for more than ten years now. Because of their mechanical and thermal stability, these compounds are advantageous for common thermoelectric materials such as Bi 2 Te 3 , SiGe, clathrates or filled skutterudites. A further advantage lies in the tunability of Heusler compounds, allowing one to avoid expensive and toxic elements...
April 23, 2018: Materials
https://www.readbyqxmd.com/read/29690524/sigma-routing-metric-for-rpl-protocol
#3
Paul Sanmartin, Aldo Rojas, Luis Fernandez, Karen Avila, Daladier Jabba, Sebastian Valle
This paper presents the adaptation of a specific metric for the RPL protocol in the objective function MRHOF. Among the functions standardized by IETF, we find OF0, which is based on the minimum hop count, as well as MRHOF, which is based on the Expected Transmission Count (ETX). However, when the network becomes denser or the number of nodes increases, both OF0 and MRHOF introduce long hops, which can generate a bottleneck that restricts the network. The adaptation is proposed to optimize both OFs through a new routing metric...
April 21, 2018: Sensors
https://www.readbyqxmd.com/read/29689761/rf-ablation-thermal-simulation-model-parameter-sensitivity-analysis
#4
Xiaoru Wang, Hongjian Gao, Shuicai Wu, Yanping Bai, Zhuhuang Zhou
OBJECTIVE: The aim of the research is to obtain the relative influences of some critical electro-thermal parameters on the ablation temperature and lesion volume during temperature-controlled radiofrequency ablation (RFA) of liver tumor by parameter sensitivity analysis. METHODS: The finite element method (FEM) has been used to establish the simulation model of RFA temperature field, and the sensitivity of the tissue parameters has been analyzed. The effects of six parameters have been taken into account, including the thermal specific capacity (Cp), the thermal conductivity (k), the electrical conductivity (Sigma), the density (rho), the dielectric constant (Epsilon) and the resistance (R)...
April 10, 2018: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
https://www.readbyqxmd.com/read/29686772/effects-of-7-mega-tm-500-on-oxidative-stress-inflammation-and-skin-regeneration-in-h-2-o-2-treated-skin-cells
#5
In-Bong Song, Hyejung Gu, Hye-Ju Han, Na-Young Lee, Ji-Yun Cha, Yeon-Kyong Son, Jungkee Kwon
Environmental stimuli can lead to the excessive accumulation of reactive oxygen species (ROS), which is one of the risk factors for premature skin aging. Here, we investigated the protective effects of 7-MEGATM 500 (50% palmitoleic acid, 7-MEGA) against oxidative stress-induced cellular damage and its underlying therapeutic mechanisms in the HaCaT human skin keratinocyte cell line (HaCaT cells). Our results showed that treatment with 7-MEGA prior to hydrogen peroxide (H2 O2 )-induced damage significantly increased the viability of HaCaT cells...
April 2018: Toxicological Research
https://www.readbyqxmd.com/read/29686109/regulation-of-global-transcription-in-escherichia-coli-by-rsd-and-6s-rna
#6
Avantika Lal, Sandeep Krishna, Aswin Sai Narain Seshasayee
In Escherichia coli , the sigma factor σ70 directs RNA polymerase to transcribe growth-related genes, while σ38 directs transcription of stress response genes during stationary phase. Two molecules hypothesized to regulate RNA polymerase are the protein Rsd, which binds to σ70 , and the non-coding 6S RNA which binds to the RNA polymerase-σ70 holoenzyme. Despite multiple studies, the functions of Rsd and 6S RNA remain controversial. Here we use RNA-Seq in five phases of growth to elucidate their function on a genome-wide scale...
April 23, 2018: G3: Genes—Genomes—Genetics
https://www.readbyqxmd.com/read/29685710/excellent-survival-and-good-outcomes-at-15-years-using-the-press-fit-condylar-sigma-total-knee-arthroplasty
#7
William M Oliver, Calum H C Arthur, Alexander M Wood, Robert A E Clayton, Ivan J Brenkel, Philip Walmsley
BACKGROUND: We report 15-year survival, clinical, and radiographic follow-up data for the Press-Fit Condylar Sigma total knee arthroplasty. METHODS: Between October 1998 and October 1999, 235 consecutive TKAs were performed in 203 patients. Patients were reviewed at a specialist nurse-led clinic before surgery and at 5, 8-10, and 15 years postoperatively. Clinical outcomes, including Knee Society Score, were recorded prospectively at each clinic visit, and radiographs were obtained...
March 27, 2018: Journal of Arthroplasty
https://www.readbyqxmd.com/read/29684473/improved-cognitive-morning-performance-in-healthy-older-adults-following-blue-enriched-light-exposure-on-the-previous-evening
#8
Karine Scheuermaier, Mirjam Münch, Joseph M Ronda, Jeanne F Duffy
OBJECTIVES: Exposure to light can have acute alerting and circadian phase-shifting effects. This study investigated the effects of evening exposure to blue-enriched polychromatic white (BEL) vs. polychromatic white light (WL) on sleep inertia dissipation the following morning in older adults. METHODS: Ten healthy older adults (average age = 63.3 yrs; 6 F) participated in a 13-day study comprising three baseline days, an initial circadian phase assessment, four days with 2-h evening light exposures, a post light exposure circadian phase assessment and three recovery days...
April 20, 2018: Behavioural Brain Research
https://www.readbyqxmd.com/read/29682701/selective-effects-of-5-ht2c-receptor-modulation-on-performance-of-a-novel-valence-probe-visual-discrimination-task-and-probabilistic-reversal-learning-in-mice
#9
Benjamin U Phillips, Sigma Dewan, Simon R O Nilsson, Trevor W Robbins, Christopher J Heath, Lisa M Saksida, Timothy J Bussey, Johan Alsiö
RATIONALE: Dysregulation of the serotonin (5-HT) system is a pathophysiological component in major depressive disorder (MDD), a condition closely associated with abnormal emotional responsivity to positive and negative feedback. However, the precise mechanism through which 5-HT tone biases feedback responsivity remains unclear. 5-HT2C receptors (5-HT2CRs) are closely linked with aspects of depressive symptomatology, including abnormalities in reinforcement processes and response to stress...
April 22, 2018: Psychopharmacology
https://www.readbyqxmd.com/read/29680498/sleep-eeg-spectral-power-is-correlated-with-subjective-objective-discrepancy-of-sleep-onset-latency-in-major-depressive-disorder
#10
Seung-Gul Kang, Sara Mariani, Stephanie A Marvin, Kwang-Pil Ko, Susan Redline, John W Winkelman
We aimed to identify the sleep electroencephalography (EEG) spectral power correlates of the subjective-objective discrepancy (SOD) of sleep onset latency (SOL) in major depressive disorder (MDD), primary insomnia (PI), and normal sleeping control (NSC) groups. We examined relative power values in standard frequency bands of the EEG spectra during the first Non-Rapid Eye Movement (NREM) sleep period as correlates of SOD of SOL between sleep diary and polysomnography in MDD (n = 36), PI (n = 19), and NSC (n = 23) groups...
April 19, 2018: Progress in Neuro-psychopharmacology & Biological Psychiatry
https://www.readbyqxmd.com/read/29677169/-dentromers-a-family-of-super-dendrimers-with-specific-properties-and-applications
#11
REVIEW
Didier Astruc, Christophe Deraedt, Rodrigue Djeda, Catia Ornelas, Xiang Liu, Amalia Rapakousiou, Jaime Ruiz, Yanlan Wang, Qi Wang
Dentromer s (from dentro, δεντρο: tree in Greek), and meros (μεροσ, in greek: part) are introduced as a family of dendrimers constructed according to successive divergent 1 → 3 branching. The smaller dentromers have 27 terminal branches. With alcohol termini they were originally named arborols by Newkome, who pioneered 1 → 3 constructions of dendrimers and dendrons. Giant dentromers have been constructed and decorated in particular with ferrocene and other redox active groups...
April 20, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29674970/hypothesis-the-psychedelic-ayahuasca-heals-traumatic-memories-via-a-sigma-1-receptor-mediated-epigenetic-mnemonic-process
#12
Antonio Inserra
Ayahuasca ingestion modulates brain activity, neurotransmission, gene expression and epigenetic regulation. N,N -Dimethyltryptamine (DMT, one of the alkaloids in Ayahuasca) activates sigma 1 receptor (SIGMAR1) and others. SIGMAR1 is a multi-faceted stress-responsive receptor which promotes cell survival, neuroprotection, neuroplasticity, and neuroimmunomodulation. Simultaneously, monoamine oxidase inhibitors (MAOIs) also present in Ayahuasca prevent the degradation of DMT. One peculiarity of SIGMAR1 activation and MAOI activity is the reversal of mnemonic deficits in pre-clinical models...
2018: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/29672992/life-in-the-fast-lane-settled-pastoralism-in-the-central-eurasian-steppe-during-the-middle-bronze-age
#13
Margaret A Judd, Jessica L Walker, Alicia Ventresca Miller, Dmitry Razhev, Andrey V Epimakhov, Bryan K Hanks
OBJECTIVES: We tested the hypothesis that the purported unstable climate in the South Urals region during the Middle Bronze Age (MBA) resulted in health instability and social stress as evidenced by skeletal response. METHODS: The skeletal sample (n = 99) derived from Kamennyi Ambar 5 (KA-5), a MBA kurgan cemetery (2040-1730 cal. BCE, 2 sigma) associated with the Sintashta culture. Skeletal stress indicators assessed included cribra orbitalia, porotic hyperostosis, dental enamel hypoplasia, and tibia periosteal new bone growth...
April 19, 2018: American Journal of Human Biology: the Official Journal of the Human Biology Council
https://www.readbyqxmd.com/read/29671217/cyproheptadine-regulates-pyramidal-neuron-excitability-in-mouse-medial-prefrontal-cortex
#14
Yan-Lin He, Kai Wang, Qian-Ru Zhao, Yan-Ai Mei
Cyproheptadine (CPH), a first-generation antihistamine, enhances the delayed rectifier outward K+ current (IK ) in mouse cortical neurons through a sigma-1 receptor-mediated protein kinase A pathway. In this study, we aimed to determine the effects of CPH on neuronal excitability in current-clamped pyramidal neurons in mouse medial prefrontal cortex slices. CPH (10 µmol/L) significantly reduced the current density required to generate action potentials (APs) and increased the instantaneous frequency evoked by a depolarizing current...
April 18, 2018: Neuroscience Bulletin
https://www.readbyqxmd.com/read/29660915/hemorheological-and-metabolic-consequences-of-renal-ischemia-reperfusion-and-their-modulation-by-n-n-dimethyl-tryptamine-on-a-rat-model
#15
Katalin Peto, Norbert Nemeth, Anita Mester, Zsuzsanna Magyar, Souleiman Ghanem, Viktoria Somogyi, Bence Tanczos, Adam Deak, Laszlo Bidiga, Ede Frecska, Balazs Nemes
BACKGROUND: Micro-rheological relations of renal ischemia-reperfusion (I/R) have not been completely elucidated yet. Concerning anti-inflammatory agents, it is supposed that sigma-1 receptor agonist N,N-dimethyl-tryptamin (DMT) can be useful to reduce I/R injury. OBJECTIVE: To investigate the micro-rheological and metabolic parameters, and the effects of DMT in renal I/R in rats. METHODS: In anesthetized rats from median laparotomy both kidneys were exposed...
April 13, 2018: Clinical Hemorheology and Microcirculation
https://www.readbyqxmd.com/read/29660299/infection-induced-thrombin-production-a-potential-novel-mechanism-for-preterm-premature-rupture-of-membranes-pprom
#16
Liping Feng, Terrence K Allen, William P Marinello, Amy P Murtha
BACKGROUND: Preterm premature rupture of membranes (PPROM) is a leading contributor to maternal and neonatal morbidity and mortality. Epidemiologic and experimental studies have demonstrated that thrombin causes fetal membrane weakening and subsequently PPROM. Although blood is suspected as the likely source of thrombin in fetal membranes and amniotic fluid of patients with PPROM, this has not been proven. Ureaplasma Parvum (U. parvum) is emerging as a pathogen involved in prematurity, including PPROM, but until now, prothrombin production directly induced by bacteria in fetal membranes has not been described...
April 13, 2018: American Journal of Obstetrics and Gynecology
https://www.readbyqxmd.com/read/29659762/activation-of-%C3%AF-20-dependent-recombination-and-horizontal-gene-transfer-in-mycoplasma-genitalium
#17
Sergi Torres-Puig, Carlos Martínez-Torró, Ignasi Granero-Moya, Enrique Querol, Jaume Piñol, Oscar Q Pich
In the human pathogen Mycoplasma genitalium, homologous recombination is under the control of σ20, an alternative sigma factor that boosts the generation of genetic and antigenic diversity in the population. Under laboratory growth conditions, σ20 activation is rare and the factors governing its intermittent activity are unknown. Two σ20-regulated genes, rrlA and rrlB, showed to be important for recombination of homologous DNA sequences in this bacterium. Herein, we demonstrate that rrlA and rrlB code for two small proteins that participate in a feed-forward loop essential for σ20 function...
April 11, 2018: DNA Research: An International Journal for Rapid Publication of Reports on Genes and Genomes
https://www.readbyqxmd.com/read/29659191/optimised-arid1a-immunohistochemistry-is-an-accurate-predictor-of-arid1a-mutational-status-in-gynaecological-cancers
#18
Saira Khalique, Kalnisha Naidoo, Ayoma D Attygalle, Divya Kriplani, Frances Daley, Anne Lowe, James Campbell, Thomas Jones, Michael Hubank, Kerry Fenwick, Nicholas Matthews, Alistair G Rust, Christopher J Lord, Susana Banerjee, Rachael Natrajan
ARID1A is a tumour suppressor gene that is frequently mutated in clear cell and endometrioid carcinomas of the ovary and endometrium and is an important clinical biomarker for novel treatment approaches for patients with ARID1A defects. However, the accuracy of ARID1A immunohistochemistry (IHC) as a surrogate for mutation status has not fully been established for patient stratification in clinical trials. Here we tested whether ARID1A immunohistochemistry could reliably predict ARID1A mutations identified by next-generation sequencing...
April 16, 2018: Journal of Pathology. Clinical Research
https://www.readbyqxmd.com/read/29658449/-intrauterine-growth-status-of-twin-neonates-with-a-gestational-age-of-27-40-weeks
#19
Xiao-Yun Huang, Hui-Long Liu, Min Lei, Zhao-Hui Lian, Hui-Fen Mai
OBJECTIVE: To establish the intrauterine growth curve of twin neonates, and to investigate the intrauterine growth status of twin neonates. METHODS: Cross-sectional cluster sampling was performed for an on-the-spot investigation of 1 296 live twin neonates who were born in two hospitals in Shenzhen between April 2013 and September 2015. The Lambda-Mu-Sigma method was used for the curve fitting of body weight, body length, head circumference, chest circumference, and crown-rump length...
April 2018: Zhongguo Dang Dai Er Ke za Zhi, Chinese Journal of Contemporary Pediatrics
https://www.readbyqxmd.com/read/29656199/investigating-isoindoline-tetrahydroisoquinoline-and-tetrahydrobenzazepine-scaffolds-for-their-sigma-receptor-binding-properties
#20
Kathryn Linkens, Hayden R Schmidt, James J Sahn, Andrew C Kruse, Stephen F Martin
Substituted norbenzomorphans are known to display high affinity and selectivity for the two sigma receptor (σR) subtypes. In order to study the effects of simplifying the structures of these compounds, a scaffold hopping strategy was used to design several novel sets of substituted isoindolines, tetrahydroisoquinolines and tetrahydro-2-benzazepines. The binding affinities of these new compounds for the sigma 1 (σ1R) and sigma 2 (σ2R) receptors were determined, and some analogs were identified that exhibit high affinity (Ki  ≤ 25 nM) and significant selectivity (>10-fold) for σ1R or σ2R...
March 29, 2018: European Journal of Medicinal Chemistry
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