29,329 results match your criteria Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology[Journal]


Effects of bensulfuron-methyl residue on photosynthesis and chlorophyll fluorescence in leaves of cucumber seedlings.

PLoS One 2019 23;14(4):e0215486. Epub 2019 Apr 23.

Institute of Plant Protection, Henan Academy of Agricultural Sciences, Henan Key Laboratory of Crop Pest Control, IPM key laboratory in the southern part of North China for Ministry of Agriculture, Zhengzhou, China.

A potted soil experiment was conducted to investigate the effects of bensulfuron-methyl (BSM) residue on the growth and photosynthesis of seedlings of a local cucumber variety (Xia Feng No.1). When the residue of bensulfuron-methyl in soil exceeded 50μg kg-1, it significantly inhibited the growth of cucumber, chlorophyll content and photosynthetic capacity of cucumber. Read More

View Article

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215486PLOS
April 2019
1 Read

Push-Pull Stilbene: Visible Light Activated Photoremovable Protecting Group for Alcohols and Carboxylic Acids with Fluorescence Reporting Employed for Drug Delivery.

Org Lett 2019 Apr 23. Epub 2019 Apr 23.

For the first time we have utilized push-pull stilbene as a visible light activated photoremovable protecting group (PRPG) for the uncaging of alcohols and carboxylic acids. The PRPG efficiently release caged molecules with good photochemical quantum yield. It is capable of monitoring the release in real time owing to its fluorescence "turn on" phenomenon upon photorelease in polar medium. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.9b00124DOI Listing

Probing eumelanin photoprotection using a catechol:quinone heterodimer model system.

Faraday Discuss 2019 Apr 23. Epub 2019 Apr 23.

Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.

Eumelanin is a natural pigment with photoprotective and radical scavenging characteristics, which are vital for a multitude of living organisms. However, the molecular mechanisms behind these functions remain obscure, in part because eumelanin is a heterogeneous polymer composed of a complex assortment of structural and chemical domains. Despite uncertainty about its precise structure, the functional units of eumelanin are thought to include quinones in various oxidation states. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8fd00231bDOI Listing

Photochemical Etching of Carbonyl Groups from a Carbon Matrix: The (001) Diamond Surface.

Phys Rev Lett 2019 Jan;122(1):016802

MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, New South Wales 2109, Australia.

The surface of diamond is reported to undergo nonablative photochemical etching when exposed to ultraviolet (UV) radiation which allows controlled single and partial layer removal of lattice layers. Oxygen termination of surface dangling bonds is known to be crucial for the etching process; however, the exact mechanism of carbon ejection remains unclear. We investigate the interaction of UV laser pulses with oxygen-terminated diamond surfaces using atomic-scale surface characterization combined with first-principles time-dependent density functional theory calculations. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.122.016802DOI Listing
January 2019

Protein conformational alterations induced by the retinal excited state in proton and sodium pumping rhodopsins.

Phys Chem Chem Phys 2019 Apr 23. Epub 2019 Apr 23.

Department of Organic Chemistry, Weizmann Institute of Science Rehovot, Israel.

Retinal proteins' biological activity is triggered by the retinal chromophore's light absorption, which initiates a photocycle. However, the mechanism by which retinal light excitation induces the protein's response is not completely understood. Recently, two new retinal proteins were discovered, namely, King Sejong 1-2 (KS1-2) and Nonlabens (Donghaeana) dokdonensis (DDR2), which exhibit H+ and Na+ pumping activities, respectively. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9cp00681hDOI Listing

Color Patterning of Luminescent Perovskites via Light-Mediated Halide Exchange with Haloalkanes.

Adv Mater 2019 Apr 22:e1901247. Epub 2019 Apr 22.

Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore.

Lead halide perovskite possesses a semiconductor bandgap that is readily tunable by a variation in its halide composition. Here, a photo-activated halide exchange process between perovskite nanocrystals and molecular haloalkanes is reported, which enables the perovskite luminescence to be controllably shifted across the entire visible spectrum. Mechanistic investigations reveal a mutual exchange of halogens between the perovskite crystal surface and a chemisorbed haloalkane, yielding nanocrystals and haloalkanes with mixed halide contents. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1002/adma.201901247DOI Listing

How to Design Donor-Acceptor Based Heterocyclic Conjugated Polymers for Applications from Organic Electronics to Sensors.

Top Curr Chem (Cham) 2019 Apr 22;377(3):12. Epub 2019 Apr 22.

Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai, Tamil Nadu, 600025, India.

Over the past few years, significant progress has been made in the design of organic semi-conducting conjugated polymers that readily transport holes or electrons and can result in light emission. The conjugated backbone consist mainly of electron-donating (donor) and electron-withdrawing (acceptor) units as alternating groups in a conjugated oligomer or polymer that can be regulated by physical properties such as π conjugation length, monomer alteration, inter/intramolecular interactions and energy levels. Certainly, it is notable today that the highest occupied molecular orbital level of the producing material is localized predominantly on the electron-donating moiety and lowest unoccupied molecular orbital level on the electron-accepting moiety. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s41061-019-0237-4DOI Listing

Carbonic anhydrase activity as a potential biomarker for acute exposure to copper in corals.

Chemosphere 2019 Apr 15;227:598-605. Epub 2019 Apr 15.

Instituto Coral Vivo, Rua dos Coqueiros, Parque Yaya, Santa Cruz Cabrália, BA, 45807-000, Brazil; Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Av. Itália, Km 8, Rio Grande, RS, 96203-900, Brazil. Electronic address:

Coral reefs are subjected to climate change and are severely impacted by human activities, with copper (Cu) being a relevant physiological stressor for corals at local scale. The ecological relevance of parameters measured at biochemical or cellular level is now considered an extremely important feature in environmental studies, and can be used as early warning signs of environmental degradation. In this context, the effects of acute exposure (96 h) to Cu were assessed on the maximum photochemical efficiency of zooxanthellae (Fv/Fm) and on the activity of key enzymes [carbonic anhydrase (CA) and Ca-ATPase] involved in coral physiology using the scleractinian coral Mussismilia harttii as a biological model. Read More

View Article

Download full-text PDF

Source
https://linkinghub.elsevier.com/retrieve/pii/S00456535193074
Publisher Site
http://dx.doi.org/10.1016/j.chemosphere.2019.04.089DOI Listing
April 2019
1 Read

Visible-Light Excitation of Quinolinone-Containing Substrates Enables Divergent Radical Cyclizations.

Org Lett 2019 Apr 22. Epub 2019 Apr 22.

Center for Catalytic Hydrocarbon Functionalizations , Institute for Basic Science (IBS) , Daejeon 34141 , Korea.

Reported herein is the photochemical activity of quinolinone-containing substrates that directly reach an excited state upon light absorption to trigger radical-based bond-forming processes. The presented transformations allow divergent construction of valuable dihydro- or tetrahydrophenanthridin-6(5 H)-ones through the generation of S- or P-centered radicals, subsequent radical addition, cyclization, and a hydrogen atom transfer/electron transfer sequence. This strategy demonstrates the potential generality of quinolinone-tethered substrates to directly participate in the photoexcitation for the development of useful synthetic methods. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.9b01155DOI Listing

Updates to the Noah Land Surface Model in WRF-CMAQ to Improve Simulated Meteorology, Air Quality, and Deposition.

J Adv Model Earth Syst 2019 Jan 18;11(1):231-256. Epub 2019 Jan 18.

National Exposure Research Laboratory U.S. Environmental Protection Agency Durham NC USA.

Regional, state, and local environmental regulatory agencies often use Eulerian models to investigate the potential impacts on pollutant deposition and air quality from changes in land use, anthropogenic and natural emissions, and climate. The Noah land surface model (LSM) in the Weather Research and Forecasting (WRF) model is widely used with the Community Multiscale Air Quality (CMAQ) model for such investigations, but there are many inconsistencies that need to be changed so that they are consistent with dry deposition and emission processes. In this work, the Noah LSM in WRFv3. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1029/2018MS001422DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6472559PMC
January 2019

The role of photodynamic therapy on multidrug resistant breast cancer.

Cancer Cell Int 2019 11;19:91. Epub 2019 Apr 11.

Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, Johannesburg, 2028 South Africa.

Breast cancer heterogeneity allows cells with different phenotypes to co-exist, contributing to treatment failure and development of drug resistance. In addition, abnormal signal transduction and dysfunctional DNA repair genes are common features with breast cancer resistance. Chemo-resistance of breast cancer associated with multidrug resistance events utilizes ATP-binding cassette (ABC) efflux transporters to decrease drug intracellular concentration. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12935-019-0815-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6458738PMC

Photochemical Synthesis of ,,-1,2,3,4-Tetrakis(diphenylphosphanyl)buta-1,3-diene and Its Metal Coordination.

Eur J Inorg Chem 2018 Dec 8;2018(46):4962-4971. Epub 2018 Nov 8.

Institute of General, Inorganic and Theoretical Chemistry Centrum for Chemistry and Biomedicine University of Innsbruck Innrain 80-82, A -6020 Innsbruck Austria.

The new bis(bidentate) tetraphosphane ,,-1,2,3,4-tetrakis(diphenylphosphanyl)buta-1,3-diene (dppbd) () was obtained by applying a photochemical synthetic protocol. The key step of the photochemical reaction consisted of an intramolecular [2+2] cycloaddition involving a C-C double and triple bond of the Pt-dimer species of the formula [PtCl(dppa)(-dppen)] () {dppa = 1,2-bis(diphenylphosphanyl)acetylene and dppen = 1,2-bis(diphenylphosphanyl)ethene} leading to [PtCl(dppbd)] (). The asymmetrically bridged precursor complex was obtained by combinatorial chemistry. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1002/ejic.201800804DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6471117PMC
December 2018

Cerebrovascular Injuries Induce Lymphatic Invasion into Brain Parenchyma to Guide Vascular Regeneration in Zebrafish.

Dev Cell 2019 Apr 8. Epub 2019 Apr 8.

Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China. Electronic address:

Damage to regional cerebrovascular networks and neuronal tissues occurs during acute cerebrovascular diseases, such as ischemic stroke. The promotion of vascular regeneration is the most promising therapeutic approach. To understand the cellular and molecular mechanisms underlying brain vascular regeneration, we developed two zebrafish cerebrovascular injury models using genetic ablation and photochemical thrombosis. Read More

View Article

Download full-text PDF

Source
https://linkinghub.elsevier.com/retrieve/pii/S15345807193023
Publisher Site
http://dx.doi.org/10.1016/j.devcel.2019.03.022DOI Listing
April 2019
1 Read

Exogenous putrescine alleviates photoinhibition caused by salt stress through cooperation with cyclic electron flow in cucumber.

Photosynth Res 2019 Apr 19. Epub 2019 Apr 19.

College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.

When plants suffer from abiotic stresses, cyclic electron flow (CEF) is induced for photo-protection. Putrescine (Put), a primary polyamine in chloroplasts, plays a critical role in stress tolerance. However, the relationship between CEF and Put in chloroplasts for photo-protection is unknown. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11120-019-00631-yDOI Listing

Dynamics Properties of Photosynthetic Microorganisms Probed by Incoherent Neutron Scattering.

Biophys J 2019 Apr 2. Epub 2019 Apr 2.

CNR Istituto di Cristallografia, Monterotondo Stazione, Rome, Italy.

Studies on the dynamical properties of photosynthetic membranes of land plants and purple bacteria have been previously performed by neutron spectroscopy, revealing a tight coupling between specific photochemical reactions and macromolecular dynamics. Here, we probed the intrinsic dynamics of biotechnologically useful mutants of the green alga Chlamydomonas reinhardtii by incoherent neutron scattering coupled with prompt chlorophyll fluorescence experiments. We brought to light that single amino acid replacements in the plastoquinone (PQ)-binding niche of the photosystem II D1 protein impair electron transport (ET) efficiency between quinones and confer increased flexibility to the host membranes, expanding to the entire cells. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bpj.2019.03.029DOI Listing

Effects of row direction and row spacing on maize leaf senescence.

PLoS One 2019 18;14(4):e0215330. Epub 2019 Apr 18.

Northeast Institute of Geography and Agroecology, CAS, Changchun, China.

To analyze three row orientations (south-north, east-west, southwestern 20°) and two row spacings ('65 + 65', '160 + 40'), we investigated the effect of row orientation and planting pattern on photosynthetic performance, physiological and biochemical indicators related to the aging of leaves. Results revealed that during maturity stage, in north-south and east-west, the initial fluorescence (Fo) at '65 + 65' were higher than those under'160 + 40'; the maximum quantum yield of PS2 photochemistry(ΦP0), basal quantum yield of non-photochemical processes in PS2(ΦN0)of the lower leaves and photosynthetic rate of the upper and ear leaves under'160 + 40'were higher than those under'65 + 65'. The polyphenoloxidase (POD) activities of leaves at different positions under '160 + 40' were higher than that under'65 + 65', while the malondialdehyde (MDA) content was lower. Read More

View Article

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215330PLOS
April 2019
5 Reads

A Photochemical Route towards Metal Sulfide Nanosheets from Layered Metal Thiolate Complexes.

Angew Chem Int Ed Engl 2019 Apr 18. Epub 2019 Apr 18.

Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences (CAS), Key Laboratory of Photochemical Conversion and Optoelectronic Materials, No.29 Zhongguancun East Road, Haidian District,, 100190, Beijing, CHINA.

Synthesizing nanomaterials with anisotropic architectures, especially two-dimensional (2D) nanosheets (NSs), is a key focus of materials science research. Metal sulfide nanosheets (MSNSs) are typically obtained involving exfoliation of bulk metal sulfides with layered structures. The synthesis of NSs of intrinsically non-layered metal sulfides has received relatively less attention. Read More

View Article

Download full-text PDF

Source
http://doi.wiley.com/10.1002/anie.201902791
Publisher Site
http://dx.doi.org/10.1002/anie.201902791DOI Listing
April 2019
3 Reads
11.261 Impact Factor

Photoreaction Dynamics of Red-Shifting Retinal Analogues Reconstituted in Proteorhodopsin.

J Phys Chem B 2019 Apr 18. Epub 2019 Apr 18.

Microbial rhodopsins constitute a key protein family in optobiotechnological applications such as optogenetics and voltage imaging. Spectral tuning of rhodopsins into the deep red and near-infrared spectral regions is of great demand in such applications since more bathochromic light into the near-infrared range penetrates deeper in living tissue. Recently, retinal analogues have been successfully used in ion transporting and fluorescent rhodopsins to achieve red-shifted absorption, activity and emission properties. Read More

View Article

Download full-text PDF

Source
http://pubs.acs.org/doi/10.1021/acs.jpcb.9b01136
Publisher Site
http://dx.doi.org/10.1021/acs.jpcb.9b01136DOI Listing
April 2019
2 Reads

8-Mercaptoquinoline as Ligand for Enhancing the Photocatalytic Activity of Pt(II) Coordination Complexes: Reactions and Mechanistic Insights.

J Org Chem 2019 Apr 18. Epub 2019 Apr 18.

A family of quinoline-platinum(II) complexes as efficient photocatalysts is presented. Their key characteristic is their easy preparation by coordination of the readily available 8-hydroxy- or 8-thio-quinolines ligands, which are well known for their strong chelating ability to different metal ions. In the different photochemical transformations investigated, such as cross-dehydrogenative couplings, oxidation of aryl boronic acids and asymmetric alkylations of aldehydes, the 8-mercaptoquinoline-Pt(II) complex proved to be the most general catalyst. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.joc.9b00520DOI Listing
April 2019
1 Read

IN VITRO AND IN VIVO INVESTIGATION OF CHLOROPHYLL BINDING SITES INVOLVED IN NON-PHOTOCHEMICAL QUENCHING IN CHLAMYDOMONAS REINHARDTII.

Plant Cell Environ 2019 Apr 18. Epub 2019 Apr 18.

Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy.

Non-photochemical quenching (NPQ) of the light energy absorbed is one of the main photoprotective mechanisms evolved by oxygenic photosynthetic organisms to avoid photodamage, at a cost of reduced photosynthetic efficiency. Tuning of NPQ has been reported as a promising biotechnological strategy to increase productivity in both higher plants and unicellular microalgae. Engineering of NPQ induction requires the comprehension of its molecular mechanism(s), strongly debated in the last three decades with several different models proposed. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1111/pce.13566DOI Listing

Air pollution survey across the western Mediterranean Sea: overview on oxygenated volatile hydrocarbons (OVOCs) and other gaseous pollutants.

Environ Sci Pollut Res Int 2019 Apr 17. Epub 2019 Apr 17.

National Research Council of Italy, Institute of Atmospheric Pollution Research (CNR.IIA), Monterotondo, RM, Italy.

Despite the Mediterranean Sea basin is among the most sensitive areas over the world for climate change and air quality issues, it still remains less studied than the oceanic regions. The domain investigated by the research ship Minerva Uno cruise in Summer 2015 was the Tyrrhenian Sea. An overview on the marine boundary layer (MBL) concentration levels of carbonyl compounds, ozone (O), and sulfur dioxide (SO) is reported. Read More

View Article

Download full-text PDF

Source
http://link.springer.com/10.1007/s11356-019-04916-6
Publisher Site
http://dx.doi.org/10.1007/s11356-019-04916-6DOI Listing
April 2019
2 Reads

Ultralow-temperature photochemical synthesis of atomically dispersed Pt catalysts for the hydrogen evolution reaction.

Chem Sci 2019 Mar 19;10(9):2830-2836. Epub 2019 Jan 19.

State Key Laboratory of New Ceramics and Fine Processing , School of Materials Science and Engineering , Tsinghua University , Beijing , 100084 , China . Email:

Efficient control of nucleation is a prerequisite for the solution-phase synthesis of nanocrystals. Although the thermodynamics and kinetics of the formation of metal nanoparticles have been largely investigated, fully suppressing the nucleation in solution synthesis remains a major challenge due to the high surface free energy of isolated atoms. In this article, we largely decreased the reaction temperature for ultraviolet (UV) photochemical reduction of HPtCl solution to -60 °C and demonstrated such a method as a fast and convenient process for the synthesis of atomically dispersed Pt. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8sc04986fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6431957PMC

Achieving an exceptionally high loading of isolated cobalt single atoms on a porous carbon matrix for efficient visible-light-driven photocatalytic hydrogen production.

Chem Sci 2019 Mar 16;10(9):2585-2591. Epub 2019 Jan 16.

Chemical Sciences Division , Oak Ridge National Laboratory , Oak Ridge , TN 37831 , USA . Email:

Single-atom catalysts (SACs) have shown great potential in a wide variety of chemical reactions and become the most active new frontier in catalysis due to the maximum efficiency of metal atom use. The key obstacle in preparing SAs lies in the development of appropriate supports that can avoid aggregation or sintering during synthetic procedures. As such, achieving high loadings of isolated SAs is nontrivial and challenging. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8sc05540hDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6428031PMC

A chemical reaction controlled by light-activated molecular switches based on hetero-cyclopentanediyls.

Chem Sci 2019 Mar 18;10(12):3486-3493. Epub 2019 Feb 18.

Institute of Chemistry , University of Rostock , Albert-Einstein-Str. 3a , D-18059 Rostock , Germany . Email: ; Email:

Molecular switches are molecules that can reversibly be shifted between at least two stable states with different physical and chemical properties, making them interesting for application as chemical sensors or molecular machines. We recently discovered that five-membered, cyclic biradicals based on group 15 elements are efficient and robust photochemical switches that can be activated by red light. The quantum yield of the photo-isomerization is as high as 24. Read More

View Article

Download full-text PDF

Source
http://xlink.rsc.org/?DOI=C8SC04893B
Publisher Site
http://dx.doi.org/10.1039/c8sc04893bDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6430090PMC
March 2019
1 Read

Orthogonal shortwave infrared emission based on rare earth nanoparticles for interference-free logical codes and bio-imaging.

Chem Sci 2019 Mar 24;10(11):3281-3288. Epub 2019 Jan 24.

Department of Chemistry , Capital Normal University , Beijing 100048 , People's Republic of China.

Shortwave infrared (SWIR) photoluminescence has received intense interest in many fields in recent years thanks to the advantages of its wide wavelength range and high tissue imaging ability and it is invisible to the naked eye. However, achieving orthogonal SWIR emission still remains a challenge. In the present study, synthesized NaErF@NaLuF (Er@Lu) and NaYF:Nd@NaLuF (Y:Nd@Lu) nanoparticles emitted atom-like SWIR emission, and the separation distance between the SWIR emission was beyond 50 nm, which permitted orthogonal SWIR signal acquirement with optical filters. Read More

View Article

Download full-text PDF

Source
http://xlink.rsc.org/?DOI=C8SC05044A
Publisher Site
http://dx.doi.org/10.1039/c8sc05044aDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6429594PMC
March 2019
1 Read

Transition-metal-free α-arylation of oxindoles a visible-light-promoted electron transfer.

Chem Sci 2019 Mar 22;10(10):3049-3053. Epub 2019 Jan 22.

Key Laboratory of Medicinal Chemistry for Natural Resources (Ministry of Education and Yunnan Province) , School of Chemical Science and Technology , Yunnan University , 2 North Cuihu Road , Kunming 650091 , China . Email:

An operationally simple photochemical strategy for the direct arylation of oxindoles with (hetero)aryl halides in the absence of both transition metals and photoredox catalysts has been developed. The reaction provides an efficient way to construct various 3-aryloxindole building blocks of pharmaceutical interest at ambient temperature by using household compact fluorescent light (CFL) bulbs as the light source. Preliminarily, mechanistic studies revealed that the intermolecular electron transfer relied on the formation of photon-absorbing electron-donor-acceptor (EDA) complexes between electron-rich oxindole enolates and electron-deficient (hetero)aryl halides, and a radical chain mechanism was operative. Read More

View Article

Download full-text PDF

Source
http://xlink.rsc.org/?DOI=C8SC05170D
Publisher Site
http://dx.doi.org/10.1039/c8sc05170dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6427940PMC
March 2019
2 Reads

Nox2 NADPH oxidase is dispensable for platelet activation or arterial thrombosis in mice.

Blood Adv 2019 Apr;3(8):1272-1284

Department of Internal Medicine.

Deficiency of the Nox2 (gp91phox) catalytic subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is a genetic cause of X-linked chronic granulomatous disease, a condition in which patients are prone to infection resulting from the loss of oxidant production by neutrophils. Some studies have suggested a role for superoxide derived from Nox2 NADPH oxidase in platelet activation and thrombosis, but data are conflicting. Using a rigorous and comprehensive approach, we tested the hypothesis that genetic deficiency of Nox2 attenuates platelet activation and arterial thrombosis. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1182/bloodadvances.2018025569DOI Listing

Effect of differently methyl-substituted ionic liquids on Scenedesmus obliquus growth, photosynthesis, respiration, and ultrastructure.

Environ Pollut 2019 Apr 10;250:155-165. Epub 2019 Apr 10.

School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China. Electronic address:

Concerns have been raised regarding the ecotoxicity of ionic liquids (ILs) owing to their wide usage in numerous fields. Three imidazolium chloride ILs with different numbers of methyl substituents, 1-decyl-imidazolium chloride ([CIM]Cl), 1-decyl-3-methylimidazolium chloride ([CMIM]Cl), and 1-decyl-2,3-dimethylimidazolium chloride ([CDMIM]Cl), were examined to assess their effects on growth, photosynthesis pigments content, chlorophyll fluorescence, photosynthetic and respiration rate, and cellular ultrastructure of Scenedesmus obliquus. The results showed that algal growth was significantly inhibited by ILs treatments. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2019.04.021DOI Listing
April 2019
1 Read

Bile Acid Binding Protein Functionalization Leads to a Fully Synthetic Rhodopsin Mimic.

J Phys Chem Lett 2019 Apr 22:2235-2243. Epub 2019 Apr 22.

Dipartimento di Biotecnologie, Chimica e Farmacia (Dipartimento di Eccellenza 2018-2022) , Università degli Studi di Siena , Via Aldo Moro 2 , 53100 Siena , Italy.

Rhodopsins are photoreceptive proteins using light to drive a plethora of biological functions such as vision, proton and ion pumping, cation and anion channeling, and gene and enzyme regulation. Here we combine organic synthesis, NMR structural studies, and photochemical characterization to show that it is possible to prepare a fully synthetic mimic of rhodopsin photoreceptors. More specifically, we conjugate a bile acid binding protein with a synthetic mimic of the rhodopsin protonated Schiff base chromophore to achieve a covalent complex featuring an unnatural protein host, photoswitch, and photoswitch-protein linkage with a reverse orientation. Read More

View Article

Download full-text PDF

Source
http://pubs.acs.org/doi/10.1021/acs.jpclett.9b00210
Publisher Site
http://dx.doi.org/10.1021/acs.jpclett.9b00210DOI Listing
April 2019
2 Reads
7.458 Impact Factor

A nuclear permeable Ru(ii)-based photoactivated chemotherapeutic agent towards a series of cancer cells: in vitro and in vivo studies.

Dalton Trans 2019 Apr 17. Epub 2019 Apr 17.

Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.

Ru(ii) polypyridyl complexes which can undergo photo-induced ligand dissociation and DNA covalent binding are considered as potential photoactivated chemotherapeutic (PACT) agents. Herein four pyridine-2-sulfonate (py-SO3-) ligand based Ru(ii) complexes [Ru(N-N)2(py-SO3)]+ (1-4) were synthesized and studied. All the complexes can undergo fast py-SO3- ligand dissociation and DNA covalent binding upon visible light irradiation. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9dt00441fDOI Listing
April 2019
1 Read

Effect of alkali ions on optical properties of flavins: vibronic spectra of cryogenic Mlumiflavin complexes (M = Li-Cs).

Faraday Discuss 2019 Apr 17. Epub 2019 Apr 17.

Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany. and Tokyo Tech World Research Hub Initiative (WRHI), Institute of Innovation Research, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama, Japan.

Flavin compounds are frequently used by nature in photochemical processes because of their unique optical properties which can be strongly modulated by the surrounding environment such as solvation or coordination with metal ions. Herein, we employ vibronic photodissociation spectroscopy of cryogenic M+LF complexes composed of lumiflavin (LF, C13H12N4O2), the parent molecule of the flavin family, and alkali ions (M = Li-Cs) to characterize the strong impact of metalation on the electronic properties of the LF chromophore. With the aid of time-dependent density functional theory calculations (PBE0/cc-pVDZ) coupled to multidimensional Franck-Condon simulations, the visible photodissociation (VISPD) spectra of M+LF ions recorded in the 500-570 nm range are assigned to the S1 ← S0 (ππ*) transitions into the first optically bright S1 state of the lowest-energy M+LF(O4+) isomers. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8fd00203gDOI Listing

Electronic spectroscopy and nanocalorimetry of hydrated magnesium ions [Mg(HO)], n = 20-70: spontaneous formation of a hydrated electron?

Faraday Discuss 2019 Apr 17. Epub 2019 Apr 17.

Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.

Hydrated singly charged magnesium ions [Mg(H2O)n]+ are thought to consist of an Mg2+ ion and a hydrated electron for n > 15. This idea is based on mass spectra, which exhibit a transition from [MgOH(H2O)n-1]+ to [Mg(H2O)n]+ around n = 15-22, black-body infrared radiative dissociation, and quantum chemical calculations. Here, we present photodissociation spectra of size-selected [Mg(H2O)n]+ in the range of n = 20-70 measured for photon energies of 1. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8fd00204eDOI Listing

[Effects of nitrogen fertilizer reduction management on photosynthesis and chlorophyll fluorescence characteristics of sweetpotato].

Ying Yong Sheng Tai Xue Bao 2019 Apr;30(4):1253-1260

Crop Research Institute, Anhui Academy of Agricultural Sciences, Hefei 230031, China.

Crop productivity depends on photosynthetic source capacity. Appropriate nitrogen (N) fertilizer management is beneficial for improving growth, photosynthetic capacity and thereby increasing crops yield. A two-year pot experiment was conducted with four N treatments, i. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.13287/j.1001-9332.201904.012DOI Listing

Photochemical evolution of continental air masses and their influence on ozone formation over the South China Sea.

Sci Total Environ 2019 Apr 8;673:424-434. Epub 2019 Apr 8.

School of Atmospheric Sciences, Sun Yat-sen University, China.

To investigate photochemical ozone (O) pollution over the South China Sea (SCS), an intensive sampling campaign was conducted from August to November simultaneously at a continental site (Tung Chung, TC) and a marine site (Wan Shan Island, WSI). It was found that when continental air masses intruded the SCS, O episodes often occurred subsequently. To discover the causes, a photochemical trajectory model (PTM) coupled with the near-explicit Master Chemical Mechanism (MCM) was adopted, and the photochemical processes of air masses during the transport from TC to WSI were investigated. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2019.04.075DOI Listing

Influence of light intensity on cadmium uptake and toxicity in the cyanobacteria Synechocystis sp. PCC6803.

Aquat Toxicol 2019 Mar 25;211:163-172. Epub 2019 Mar 25.

College of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, PR China. Electronic address:

The mechanisms of cadmium toxicity to cyanobacterial photosynthesis have been extensively studied, but the response mechanisms to combinations of different cadmium concentrations and different light intensities are not yet well understood. The two principal objectives of the present work were to: 1) study the short term (5 h) toxic effects of cadmium on Synechocystis PCC6803 under three different culturing light intensity conditions; and, 2) investigate the effects of light history on Cd toxicity to Synechocystis. The maximal (Ф) and operational (Ф') photosystem II quantum yields, photosystem I quantum yield [Y (I)], cyclic electron flow, relative photochemical quenching (qPrel), relative non-photochemical quenching (qNrel), relative unquenched fluorescence (UQFrel), pigment contents, and cadmium uptake were evaluated when Synechocystis cells were treated with cadmium for 5 h under three different light conditions. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.aquatox.2019.03.016DOI Listing
March 2019
1 Read

Bifunctional Template-Induced VO@SiO Dual-Shelled Hollow Nanosphere-Based Coatings for Smart Windows.

ACS Appl Mater Interfaces 2019 Apr 16. Epub 2019 Apr 16.

School of Chemical and Environmental Engineering China University of Mining and Technology (Beijing) , Beijing 100083 , China.

Thermochromic vanadium dioxide (VO) as one of the most promising candidates for smart windows has attracted widespread attention in recent years. Excellent optical performances (luminous transmittance, T, and solar modulation efficiency, Δ T) of VO-based coatings are usually pursued as crucial issues. In the current work, we report an ingenious approach for the synthesis of VO@SiO dual-shell hollow nanospheres (DSHNs) and the preparation of DSHNs thermochromic coatings. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.8b22113DOI Listing

The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction.

Nat Chem 2019 Apr 15. Epub 2019 Apr 15.

Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.

The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactions in vitamin D synthesis. Although the relaxation from the photoexcited electronic state during the ring-opening has been investigated in numerous studies, the accompanying changes in atomic distance have not been resolved. Here we present a direct and unambiguous observation of the ring-opening reaction path on the femtosecond timescale and subångström length scale using megaelectronvolt ultrafast electron diffraction. Read More

View Article

Download full-text PDF

Source
http://www.nature.com/articles/s41557-019-0252-7
Publisher Site
http://dx.doi.org/10.1038/s41557-019-0252-7DOI Listing
April 2019
2 Reads

Indian annual ambient air quality standard is achievable by completely mitigating emissions from household sources.

Proc Natl Acad Sci U S A 2019 Apr 15. Epub 2019 Apr 15.

Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801.

Exposures to ambient and household fine-particulate matter (PM) together are among the largest single causes of premature mortality in India according to the Global Burden of Disease Studies (GBD). Several recent investigations have estimated that household emissions are the largest contributor to ambient PM exposure in the country. Using satellite-derived district-level PM exposure and an Eulerian photochemical dispersion model CAMx (Comprehensive Air Quality Model with Extensions), we estimate the benefit in terms of population exposure of mitigating household sources--biomass for cooking, space- and water-heating, and kerosene for lighting. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1900888116DOI Listing
April 2019
1 Read

Dextran-conjugated Caged siRNA Nanoparticles for Photochemical Regulation of RNAi-induced Gene Silencing in Cells and Mice.

Bioconjug Chem 2019 Apr 16. Epub 2019 Apr 16.

RNA interference (RNAi)-based gene therapy is a precision therapeutic approach for highly efficient sequence-specific gene silencing in vivo or in vitro. Caged RNAs featuring dextran conjugation of antisense and sense RNA strands using photolabile linker were rationally designed and self-assembled to form caged siRNA nanoparticles (Dex-p-siRNA) for photoregulation of target gene expression. The dextran-conjugated caged siRNA nanoparticles showed significant se-rum nuclease-resistance due to the formation of dextran-siRNA nanoparticles. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.bioconjchem.9b00204DOI Listing

Formation, Photophysics, and Photochemistry of Anionic Lanthanide(III) Mono- and Bisporphyrins.

Molecules 2019 Apr 3;24(7). Epub 2019 Apr 3.

Department of General and Inorganic Chemistry, Institute of Chemistry, Faculty of Engineering, University of Pannonia, P.O.B. 158, H-8201 Veszprém, Hungary.

Since water-soluble porphyrin complexes of lanthanides(III) have proved to be promising for medical applications (e.g., luminescence imaging, photodynamic therapy, and theranostics), the investigation of the formation, photophysical, and photochemical properties of such coordination compounds provides useful pieces of information for their potential usage. Read More

View Article

Download full-text PDF

Source
https://www.mdpi.com/1420-3049/24/7/1309
Publisher Site
http://dx.doi.org/10.3390/molecules24071309DOI Listing
April 2019
1 Read

Electrospun Gelatin Fibers Surface Loaded ZnO Particles as a Potential Biodegradable Antibacterial Wound Dressing.

Nanomaterials (Basel) 2019 Apr 3;9(4). Epub 2019 Apr 3.

Hangzhou Research Institute of Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Hangzhou 310018, China.

Traditional wound dressings require frequent replacement, are prone to bacterial growth and cause a lot of environmental pollution. Therefore, biodegradable and antibacterial dressings are eagerly desired. In this paper, gelatin/ZnO fibers were first prepared by side-by-side electrospinning for potential wound dressing materials. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.3390/nano9040525DOI Listing

Diclofenac as an environmental threat: Impact on the photosynthetic processes of Lemna minor chloroplasts.

Chemosphere 2019 Jun 1;224:892-899. Epub 2019 Mar 1.

Department of Plant Physiology and Anatomy, Institute of Experimental Biology, Faculty of Science, Masaryk University Brno, Kotlářská 2, 611 37 Brno, Czech Republic. Electronic address:

Mechanisms of pharmaceuticals action on biochemical and physiological processes in plants that determine plant growth and development are still mostly unknown. This study deals with the effects of non-steroidal anti-inflammatory drug diclofenac (DCF) on photosynthesis as an essential anabolic process. Changes in primary and secondary photosynthetic processes were assessed in chloroplasts isolated from Lemna minor exposed to 1, 10, 100, and 1000 μM DCF. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2019.02.197DOI Listing
June 2019
1 Read

Experimental and theoretical investigation on photodegradation mechanisms of naproxen and its photoproducts.

Chemosphere 2019 Apr 8;227:142-150. Epub 2019 Apr 8.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, PR China.

The photochemical degradation of the pharmaceuticals and personal care products (PPCPs) has attracted increasing attention. In this study, a deep inspection of the photolysis mechanisms of naproxen and its photoproducts has been performed by employing experimental and theoretical methods. Contributions of different reactive oxygen species (ROS, such as OH, O, and O) in the photolysis reaction also have been clarified. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2019.04.055DOI Listing

Organocatalytic Transformation of Aldehydes to Thioesters with Visible Light.

Chemistry 2019 Apr 15. Epub 2019 Apr 15.

UNITED STATES.

Here we describe a metal free and oxidant free catalytic method of accessing structurally diverse thioesters from readily accessible, widespread aldehydes. A strategy of a simple organic 9,10-phenanthrenequinone promoted hydrogen atom transfer (HAT) with visible light is successfully implemented to selectively generate acyl radicals without inducing crossover reactivity of thioester products. The preparative power of the method is demonstrated by broad substrate scope and wide functional group tolerance, and enables the late-stage modification of complex structures, which are difficult to achieve with the existing protocols. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.201900932DOI Listing

Quantifying the photoionization cross section of the hydroxyl radical.

J Chem Phys 2019 Apr;150(14):141103

Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214 CNRS, Université Paris-Sud, Université Paris-Saclay, F-91405 Orsay Cedex, France.

The hydroxyl free radical, OH, is one of the most important radicals in atmospheric and interstellar chemistry, and its cation plays a role in the reactions leading to HO formation. Knowledge of the photoionization efficiency of the OH radical is crucial to properly model the water photochemical cycle of atmospheres and astrophysical objects. Using a gas-phase radical source based on a single H-abstraction reaction combined with a photoelectron/photoion imaging coincidence spectrometer coupled with synchrotron radiation, we recorded the OH photoion yield over the 12. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.5091966DOI Listing

Leaves of isoprene-emitting tobacco plants maintain PSII stability at high temperatures.

New Phytol 2019 Apr 13. Epub 2019 Apr 13.

Department of Biology, Agriculture and Food Sciences, National Research Council of Italy, Piazzale Aldo Moro 7, 00185, Rome, Italy.

At high temperatures, isoprene-emitting plants display a higher photosynthetic rate and a lower non-photochemical quenching (NPQ) compared to non-emitting plants. The mechanism of this phenomenon, which may be very important under current climate warming, is still elusive. NPQ was dissected into its components, and chlorophyll fluorescence lifetime imaging microscopy (FLIM) was used to analyze the dynamics of excited chlorophyll relaxation in isoprene-emitting and non-emitting plants. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1111/nph.15847DOI Listing

Facile Photochemical Syntheses of Conjoined Nanotwin Gold-Silver Particles within a Biologically-Benign Chitosan Polymer.

Nanomaterials (Basel) 2019 Apr 11;9(4). Epub 2019 Apr 11.

Department of Chemistry, University of North Texas, Denton, TX 76203, USA.

A simple photochemical method for making conjoined bi-metallic gold-silver (Au/Ag) nanotwins, a new breed of nanoparticles (NPs), is developed. To the best of our knowledge, the photochemical method resulted in distinct, conjoined, bimetallic nanotwins that are different from any well-established alloyed or core-shell nanostructures in the literature. The conjoined Au-Ag NPs possessed surface plasmon resonance (SPR) properties of both metals. Read More

View Article

Download full-text PDF

Source
https://www.mdpi.com/2079-4991/9/4/596
Publisher Site
http://dx.doi.org/10.3390/nano9040596DOI Listing
April 2019
2 Reads

Molecular engineering mechanism of organic photoactive layer by alkyl chains, 4-butoxyphenyl and cyanogroup.

Spectrochim Acta A Mol Biomol Spectrosc 2019 Mar 20;218:142-154. Epub 2019 Mar 20.

School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 639798, Singapore. Electronic address:

The three organic dye molecules (JY31, JY32 and JY33) were applied to the photoactive layer in solar cells. Photophysical and photochemical characteristic have been investigated with natural bond orbital (NBO), frontier molecular orbital, ionization potentials, electron affinities, absorption properties, reorganization energies, static first hyperpolarizability, emission characteristics, IR spectra, charge density difference; the influence of alkyl chains and 4-butoxyphenyl on properties were revealed; Subsequently, three new molecules JY33-1, JY33-2 and JY33-3 were designed by inserting the electron withdrawing group -CN into the acceptor part of JY33 in order to understand molecular engineering mechanism. The results show that the three original molecules have relatively high molar extinction coefficients, and the molecule of JY33 with a 4-butoxyphenyl group enables a bathochromic shift in absorption spectrum and is beneficial to improve the hole transport, injection capacity and ICT properties as well as better energy levels matching. Read More

View Article

Download full-text PDF

Source
https://linkinghub.elsevier.com/retrieve/pii/S13861425193030
Publisher Site
http://dx.doi.org/10.1016/j.saa.2019.03.070DOI Listing
March 2019
3 Reads

Sunlight-Mediated Lead and Chromium Release from Commercial Lead Chromate Pigments in Aqueous Phase.

Environ Sci Technol 2019 Apr 12. Epub 2019 Apr 12.

Lead chromate pigments are a group of most widely-used pigments, which account for 3% of the worldwide lead consumption. This study reports the photoactivity of commercial lead chromate pigment (i.e. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.est.8b06839DOI Listing

Double benefits of mechanical wounding in enhancing chilling tolerance and lodging resistance in wheat plants.

Plant Biol (Stuttg) 2019 Apr 12. Epub 2019 Apr 12.

National Technique Innovation Center for Regional Wheat Production, Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture / National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, PR China.

Chilling and lodging are major threats to wheat production. However, strategies that can be used to effectively mitigate the adverse effects of these threats are still far from clear. Mechanical wounding is one of the traditional agronomic measures whereas information about the role it plays in wheat chilling and lodging is scanty. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1111/plb.12995DOI Listing
April 2019
1 Read
2.633 Impact Factor