keyword
MENU ▼
Read by QxMD icon Read
search

Extreme heat

keyword
https://www.readbyqxmd.com/read/29790516/ultrafast-excited-state-decay-of-natural-uv-filters-from-intermolecular-hydrogen-bonds-to-a-conical-intersection
#1
Peter S Sherin, Yuri P Tsentalovich, Eric Vauthey, Enrico Benassi
Kynurenines (KNs) are natural UV filters of the human eye lens, protecting the eye tissues from solar UV radiation. Key points of their effective protection are the intramolecular charge transfer (ICT) in the excited state and the fast dissipation of absorbed light energy into heat via the intermolecular H-bonds. Herein we report that the introduction of an unsaturated double bond in the amino acid side chain, operating as an ICT-enhancing electron donor group, drastically accelerates the internal conversion (IC) due to a conical intersection (CI) between the potential energy surfaces of the excited and ground states...
May 23, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29789939/effects-of-heat-stress-in-the-leaf-mitotic-cell-cycle-and-chromosomes-of-four-wine-producing-grapevine-varieties
#2
Ana Carvalho, Fernanda Leal, Manuela Matos, José Lima-Brito
Grapevine varieties respond differentially to heat stress (HS). HS ultimately reduces the photosynthesis and respiratory performance. However, the HS effects in the leaf nuclei and mitotic cells of grapevine are barely known. This work intends to evaluate the HS effects in the leaf mitotic cell cycle and chromosomes of four wine-producing varieties: Touriga Franca (TF), Touriga Nacional (TN), Rabigato, and Viosinho. In vitro plants with 11 months were used in a stepwise acclimation and recovery (SAR) experimental setup comprising different phases: heat acclimation period (3 h-32 °C), extreme HS (1 h-42 °C), and two recovery periods (3 h-32 °C and 24 h-25 °C), and compared to control plants (maintained in vitro at 25 °C)...
May 22, 2018: Protoplasma
https://www.readbyqxmd.com/read/29788151/sporulation-environment-influences-spore-properties-in-bacillus-evidence-and-insights-on-underlying-molecular-and-physiological-mechanisms
#3
Christelle Bressuire-Isoard, Véronique Broussolle, Frédéric Carlin
Bacterial spores are resistant to physical and chemical insults, which make them a major concern for public health and for industry. Spores help bacteria to survive extreme environmental conditions that vegetative cells cannot tolerate. Spore resistance and dormancy are important properties for applications in medicine, veterinary health, food safety, crop protection, and other domains. The resistance of bacterial spores results from a protective multilayered structure and from the unique composition of the spore core...
May 17, 2018: FEMS Microbiology Reviews
https://www.readbyqxmd.com/read/29785202/opto-thermoelectric-nanotweezers
#4
Linhan Lin, Mingsong Wang, Xiaolei Peng, Emanuel N Lissek, Zhangming Mao, Leonardo Scarabelli, Emily Adkins, Sahin Coskun, Husnu Emrah Unalan, Brian A Korgel, Luis M Liz-Marzán, Ernst-Ludwig Florin, Yuebing Zheng
Optical manipulation of plasmonic nanoparticles provides opportunities for fundamental and technical innovation in nanophotonics. Optical heating arising from the photon-to-phonon conversion is considered as an intrinsic loss in metal nanoparticles, which limits their applications. We show here that this drawback can be turned into an advantage, by developing an extremely low-power optical tweezing technique, termed opto-thermoelectric nanotweezers (OTENT). Through optically heating a thermoplasmonic substrate, alight-directed thermoelectric field can be generated due to spatial separation of dissolved ions within the heating laser spot, which allows us to manipulate metal nanoparticles of a wide range of materials, sizes and shapes with single-particle resolution...
April 2018: Nature Photonics
https://www.readbyqxmd.com/read/29782030/the-genomes-of-three-bradyrhizobium-sp-isolated-from-root-nodules-of-lupinus-albescens-grown-in-extremely-poor-soils-display-important-genes-for-resistance-to-environmental-stress
#5
Camille E Granada, Luciano K Vargas, Fernando Hayashi Sant'Anna, Eduardo Balsanelli, Valter Antonio de Baura, Fábio de Oliveira Pedrosa, Emanuel Maltempi de Souza, Tiago Falcon, Luciane M P Passaglia
Lupinus albescens is a resistant cover plant that establishes symbiotic relationships with bacteria belonging to the Bradyrhizobium genus. This symbiosis helps the development of these plants in adverse environmental conditions, such as the ones found in arenized areas of Southern Brazil. This work studied three Bradyrhizobium sp. (AS23, NAS80 and NAS96) isolated from L. albescens plants that grow in extremely poor soils (arenized areas and adjacent grasslands). The genomes of these three strains were sequenced in the Ion Torrent platform using the IonXpress library preparation kit, and presented a total number of bases of 1,230,460,823 for AS23, 1,320,104,022 for NAS80, and 1,236,105,093 for NAS96...
May 17, 2018: Genetics and Molecular Biology
https://www.readbyqxmd.com/read/29781267/highly-regular-uniform-k-3-scf-6-mn-4-phosphors-facile-synthesis-microstructures-photo-luminescence-properties-and-application-in-led-devices
#6
Hong Ming, Shuifu Liu, Lili Liu, Jiaqing Peng, Junxiang Fu, Fu Du, Xinyu Ye
A new generation of red phosphors of complex fluoride matrices activated with Mn4+ , has gained a broad interest in getting high color rendering index (CRI), low correlated color temperature (CCT) of white light-emitting diodes(WLEDs). However, besides their instability towards moisture, the extremely irregular and nonuniform morphologies of these phosphors have limited their practical industry applications. In the present study, a novel type of K3 ScF6 :Mn4+ red phosphor with highly regular, uniform and high color purity was synthesized successfully via a facile two-step co-precipitation method under mild conditions...
May 21, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29780677/the-2016-southeastern-us-drought-an-extreme-departure-from-centennial-wetting-and-cooling
#7
A Park Williams, Benjamin I Cook, Jason E Smerdon, Daniel A Bishop, Richard Seager, Justin S Mankin
The fall 2016 drought in the southeastern United States (SE US) appeared exceptional based on its widespread impacts, but the current monitoring framework that only extends from 1979-present does not readily facilitate evaluation of soil-moisture anomalies in a centennial context. A new method to extend monthly gridded soil-moisture estimates back to 1895 is developed, indicating that since 1895, October-November 2016 soil moisture (0-200 cm) in the SE US was likely the second lowest on record, behind 1954...
October 27, 2017: Journal of Geophysical Research. Atmospheres: JGR
https://www.readbyqxmd.com/read/29780527/experimental-and-theoretical-evidence-of-a-supercritical-like-transition-in-an-organic-semiconductor-presenting-colossal-uniaxial-negative-thermal-expansion
#8
Arie van der Lee, Gilles H Roche, Guillaume Wantz, Joël J E Moreau, Olivier J Dautel, Jean-Sébastien Filhol
Thermal expansion coefficients of most materials are usually small, typically up to 50 parts per million per kelvin, and positive, i.e. materials expand when heated. Some materials show an atypical shrinking behavior in one or more crystallographic directions when heated. Here we show that a high mobility thiophene-based organic semiconductor, BHH-BTBT , has an exceptionally large negative expansion between 95 and 295 K (-216 < α 2 = α b < -333 MK-1 ), being compensated by an even larger positive expansion in the perpendicular direction (287 < α 1 < 634 MK-1 )...
April 28, 2018: Chemical Science
https://www.readbyqxmd.com/read/29775938/treatment-of-perfluoroalkyl-acids-by-heat-activated-persulfate-under-conditions-representative-of-in-situ-chemical-oxidation
#9
Thomas A Bruton, David L Sedlak
Perfluoroalkyl acids (PFAAs) are a class of organic contaminants notable for their extreme persistence. The unique chemical properties of these compounds make them difficult to remove from water using most standard water treatment techniques. To gain insight into the possibility of remediating contaminated groundwater by in situ chemical oxidation with heat-activated persulfate, PFAA removal and the generation of transformation products were evaluated under laboratory conditions. Solution pH had a strong influence on the removal of perfluorooctanoic acid (PFOA), resulting in its transformation into shorter-chain perfluorocarboxylic acids (PFCAs) at pH values below 3...
April 21, 2018: Chemosphere
https://www.readbyqxmd.com/read/29775713/enhancement-of-catalytic-activity-and-thermostability-of-a-thermostable-cellobiohydrolase-from-chaetomium-thermophilum-by-site-directed-mutagenesis
#10
Chao Han, Weiguang Li, Chengyao Hua, Fengqing Sun, Pengsheng Bi, Qunqing Wang
Enzymatic saccharification of lignocellulosic biomass is increasingly applied in agricultural and industrial applications. Nevertheless, low performance in the extreme environment severely prevents the utilization of commercial enzyme preparations. To obtain cellobiohydrolases with improved catalytic activity and thermostability, structure-based rational design was performed based on a thermostable cellobiohydrolase CtCel6 from Chaetomium thermophilum. In the present study, four conserved and noncatalytic residue substitutions were generated via site-directed mutagenesis...
May 15, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29773581/dynamic-changes-between-two-lhcx-related-energy-quenching-sites-control-diatom-photoacclimation
#11
Lucilla Taddei, Volha Chukhutsina, Bernard Lepetit, Giulio R Stella, Roberto Bassi, Herbert van Amerongen, Jean-Pierre Bouly, Marianne Jaubert, Giovanni Finazzi, Angela Falciatore
Marine diatoms are prominent phytoplankton organisms, optimally performing photosynthesis in extremely variable environments. Diatoms possess a strong ability to dissipate excess absorbed energy as heat via non-photochemical quenching (NPQ). This process relies on changes in carotenoid pigment composition (xanthophyll cycle) and on specific members of the light-harvesting complex (LHC) family specialized in photoprotection (LHCX), which potentially act as NPQ effectors. However, the link between light stress, NPQ, and the existence of different LHCX isoforms is not understood in these organisms...
May 17, 2018: Plant Physiology
https://www.readbyqxmd.com/read/29768848/nanosize-fe-x-o-y-sba-3-a-comparative-study-between-conventional-and-microwave-assisted-synthesis
#12
Sunita Barik, Sushanta K Badamali, Sagarika Sahoo, Nandakishor Behera, Sudhir E Dapurkar
The present study is focussed on development of highly dispersed nanosize iron oxide (FexOy) particles within the uniform mesopore channels of SBA-3. Herein we report a comparative study between conventional incipient wetness and microwave assisted synthesis routes adopted to devise nanoparticles. The developed materials are characterised by following X-ray diffraction, high resolution transmission electron microscopy, proton induced X-ray emission, diffuse reflectance UV-visible spectroscopy, thermogravimetry and Fourier transform infrared spectroscopy...
January 1, 2018: Journal of Nanoscience and Nanotechnology
https://www.readbyqxmd.com/read/29763817/escalating-heat-stress-mortality-risk-due-to-global-warming-in-the-middle-east-and-north-africa-mena
#13
Ali Ahmadalipour, Hamid Moradkhani
Climate change will substantially exacerbate extreme temperature and heatwaves. The impacts will be more intense across the Middle East and North Africa (MENA), a region mostly characterized by hot and arid climate, already intolerable for human beings in many parts. In this study, daily climate data from 17 fine-resolution Regional Climate Models (RCMs) are acquired to calculate wet-bulb temperature and investigate the mortality risk for people aged over 65 years caused by excessive heat stress across the MENA region...
May 11, 2018: Environment International
https://www.readbyqxmd.com/read/29760050/ultrafast-nonthermal-heating-of-water-initiated-by-an-x-ray-free-electron-laser
#14
Kenneth R Beyerlein, H Olof Jönsson, Roberto Alonso-Mori, Andrew Aquila, Saša Bajt, Anton Barty, Richard Bean, Jason E Koglin, Marc Messerschmidt, Davide Ragazzon, Dimosthenis Sokaras, Garth J Williams, Stefan Hau-Riege, Sébastien Boutet, Henry N Chapman, Nicuşor Tîmneanu, Carl Caleman
The bright ultrafast pulses of X-ray Free-Electron Lasers allow investigation into the structure of matter under extreme conditions. We have used single pulses to ionize and probe water as it undergoes a phase transition from liquid to plasma. We report changes in the structure of liquid water on a femtosecond time scale when irradiated by single 6.86 keV X-ray pulses of more than 106 J/cm2 These observations are supported by simulations based on molecular dynamics and plasma dynamics of a water system that is rapidly ionized and driven out of equilibrium...
May 14, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29755105/current-and-potential-future-seasonal-trends-of-indoor-dwelling-temperature-and-likely-health-risks-in-rural-southern-africa
#15
Thandi Kapwata, Michael T Gebreslasie, Angela Mathee, Caradee Yael Wright
Climate change has resulted in rising temperature trends which have been associated with changes in temperature extremes globally. Attendees of Conference of the Parties (COP) 21 agreed to strive to limit the rise in global average temperatures to below 2 °C compared to industrial conditions, the target being 1.5 °C. However, current research suggests that the African region will be subjected to more intense heat extremes over a shorter time period, with projections predicting increases of 4⁻6 °C for the period 2071⁻2100, in annual average maximum temperatures for southern Africa...
May 10, 2018: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/29752506/examination-of-intra-operative-core-temperature-in-joint-arthroplasty-a-single-institution-prospective-observational-study
#16
Jennifer R Matos, Julie R McSwain, Bethany J Wolf, J Wesley Doty, Sylvia H Wilson
PURPOSE: Peri-operative hypothermia is associated with increased blood loss, delayed wound healing, and surgical site infections. However, it is not known when or how rapidly hypothermia develops during arthroplasty. This study observed patients undergoing lower extremity arthroplasty to identify the times of greatest heat loss or gain. METHODS: This single-institution prospective observational study enrolled 120 patients undergoing elective knee or hip arthroplasty for peri-operative temporal temperature measurements at ten prespecified intervals...
May 11, 2018: International Orthopaedics
https://www.readbyqxmd.com/read/29751981/temporal-variation-in-the-effect-of-heat-and-the-role-of-the-italian-heat-prevention-plan
#17
F de'Donato, M Scortichini, M De Sario, A de Martino, P Michelozzi
OBJECTIVES: The aim of the article is to evaluate the temporal change in the effect of heat on mortality in Italy in the last 12 years after the introduction of the national heat plan. STUDY DESIGN: Time series analysis. METHODS: Distributed lag non-linear models were used to estimate the association between maximum apparent temperature and mortality in 23 Italian cities included in the national heat plan in four study periods (before the introduction of the heat plan and three periods after the plan was in place between 2005 and 2016)...
May 8, 2018: Public Health
https://www.readbyqxmd.com/read/29750554/dispensing-pollen-via-catapult-explosive-pollen-release-in-mountain-laurel-kalmia-latifolia
#18
Callin M Switzer, Stacey A Combes, Robin Hopkins
The astonishing amount of floral diversity has inspired countless assumptions about the function of diverse forms and their adaptive significance, yet many of these hypothesized functions are untested. We investigated an often-repeated adaptive hypothesis about how an extreme floral form functions. In this study, we conducted four investigations to understand the adaptive function of explosive pollination in Kalmia latifolia, the mountain laurel. We first performed a kinematic analysis of anther movement. Second, we constructed a heat map of pollen trajectories in three-dimensional space...
June 2018: American Naturalist
https://www.readbyqxmd.com/read/29749964/peculiar-phase-diagram-with-isolated-superconducting-regions-in-thfeasn-sub-1-i-x-i-sub-o-sub-i-x-i-sub
#19
Bai-Zhuo Li, Zhi-Cheng Wang, Jia-Lu Wang, Fu-Xiang Zhang, Dong-Ze Wang, Feng-Yuan Zhang, Yu-Ping Sun, Qiang Jing, Hua-Fu Zhang, Shugang Tan, Y K Li, Chun-Mu Feng, Yu-Xue Mei, Cao Wang, Guanghan Cao
ThFeAsN&lt;sub&gt;1-&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;O&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; (0≤&lt;i&gt;x&lt;/i&gt;≤0.6) system with heavy electron doping has been studied by the measurements of X-ray diffraction, electrical resistivity, magnetic susceptibility and specific heat. The non-doped compound exhibits superconductivity at &lt;i&gt;T&lt;sub&gt;c&lt;/sub&gt;&lt;sup&gt;onset&lt;/sup&gt;&lt;/i&gt;=30 K, which is possibly due to an internal uniaxial chemical pressure that is manifested by the extremely small value of As height with respect to the Fe plane...
May 11, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29749021/satellite-sun-induced-chlorophyll-fluorescence-detects-early-response-of-winter-wheat-to-heat-stress-in-the-indian-indo-gangetic-plains
#20
Lian Song, Luis Guanter, Kaiyu Guan, Liangzhi You, Alfredo Huete, Weimin Ju, Yongguang Zhang
Extremely high temperatures represent one of the most severe abiotic stresses limiting crop productivity. However, understanding crop responses to heat stress is still limited considering the increases in both the frequency and severity of heat wave events under climate change. This limited understanding is partly due to the lack of studies or tools for the timely and accurate monitoring of crop responses to extreme heat over broad spatial scales. In this work, we use novel space-borne data of sun-induced chlorophyll fluorescence (SIF), which is a new proxy for photosynthetic activity, along with traditional vegetation indices (Normalized Difference Vegetation Index NDVI & Enhanced Vegetation Index EVI) to investigate the impacts of heat stress on winter wheat in northwestern India, one of the world's major wheat production areas...
May 10, 2018: Global Change Biology
keyword
keyword
54781
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"