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Photochemical & Photobiological... Apr 2012
Topics: History, 20th Century; History, 21st Century; Photobiology; Photochemistry
PubMed: 22415821
DOI: 10.1039/c2pp90010f -
Photochemistry and Photobiology Sep 1995
Review
Topics: Blood; Humans; Photochemistry; Sterilization
PubMed: 8570697
DOI: 10.1111/j.1751-1097.1995.tb02358.x -
Nature Materials Sep 2004Certain periodic dielectric structures can prohibit the propagation of light for all directions within a frequency range. These 'photonic crystals' allow researchers to... (Review)
Review
Certain periodic dielectric structures can prohibit the propagation of light for all directions within a frequency range. These 'photonic crystals' allow researchers to modify the interaction between electromagnetic fields and dielectric media from radio to optical wavelengths. Their technological potential, such as the inhibition of spontaneous emission, enhancement of semiconductor lasers, and integration and miniaturization of optical components, makes the search for an easy-to-craft photonic crystal with a large bandgap a major field of study. This progress article surveys a collection of robust complete three-dimensional dielectric photonic-bandgap structures for the visible and near-infrared regimes based on the diamond morphology together with their specific fabrication techniques. The basic origin of the complete photonic bandgap for the 'champion' diamond morphology is described in terms of dielectric modulations along principal directions. Progress in three-dimensional interference lithography for fabrication of near-champion diamond-based structures is also discussed.
Topics: Crystallization; Diamond; Macromolecular Substances; Molecular Conformation; Nanotechnology; Photochemistry; Photons
PubMed: 15343291
DOI: 10.1038/nmat1201 -
Molecular BioSystems Apr 2013The recent developments and future perspectives in the use of light triggered reactions in chemical biology are reviewed with the focus on novel caged compounds for... (Review)
Review
The recent developments and future perspectives in the use of light triggered reactions in chemical biology are reviewed with the focus on novel caged compounds for protein and oligonucleotide modification, phototriggered cross linking agents and the photosensitive nanomaterials.
Topics: Light; Photochemistry; Photosynthesis; Reactive Oxygen Species
PubMed: 23223543
DOI: 10.1039/c2mb25407g -
Methods in Molecular Biology (Clifton,... 2010This chapter describes the methods and specific procedures used to fabricate microstructures by soft lithography. These techniques are useful for the prototyping of... (Review)
Review
This chapter describes the methods and specific procedures used to fabricate microstructures by soft lithography. These techniques are useful for the prototyping of devices useful for applications in biotechnology. Fabrication by soft lithography does not require specialized or expensive equipment; the materials and facilities necessary are found commonly in biological and chemical laboratories in both academia and industry. The combination of the fact that the materials are low-cost and that the time from design to prototype device can be short (< 24 h) makes it possible to use and to screen rapidly devices that also can be disposable. Here we describe the procedures for fabricating microstructures with lateral dimensions as small as 1 mum. These types of microstructures are useful for microfluidic devices, cell-based assays, and bioengineered surfaces.
Topics: Biotechnology; Dimethylpolysiloxanes; Equipment Design; Microarray Analysis; Microfluidic Analytical Techniques; Microtechnology; Nanotechnology; Photochemistry; Time Factors
PubMed: 19763460
DOI: 10.1007/978-1-60327-106-6_3 -
Amyloid : the International Journal of... Mar 2017Thioflavin T (ThT) has been widely used to investigate amyloid formation since 1989. While concerns have recently been raised about its use as a probe specific for... (Review)
Review
Thioflavin T (ThT) has been widely used to investigate amyloid formation since 1989. While concerns have recently been raised about its use as a probe specific for amyloid, ThT still continues to be a very valuable tool for studying kinetic aspects of fibrillation and associated inhibition mechanisms. This review aims to provide a conceptual instruction manual, covering appropriate considerations and pitfalls related to the use of ThT. We start by giving a brief introduction to amyloid formation with focus on the morphology of different aggregate species, followed by a discussion of the quality of protein needed to obtain reliable fibrillation data. After an overview of the photochemical basis for ThT's amyloid binding properties and artifacts that may arise from this, we describe how to plan and analyze ThT assays. We conclude with recommendations for complementary techniques to address shortcomings in the ThT assay.
Topics: Amyloid; Animals; Benzothiazoles; Humans; Photochemistry; Thiazoles
PubMed: 28393556
DOI: 10.1080/13506129.2017.1304905 -
Accounts of Chemical Research Jul 2001The volume-conserving hula-twist cis/trans isomerization process has been incorporated in a general scheme for photoisomerization of polyenes, applicable to small... (Review)
Review
The volume-conserving hula-twist cis/trans isomerization process has been incorporated in a general scheme for photoisomerization of polyenes, applicable to small organic molecules as well as to protein-bound polyene chromophores. The main theme is that in solution the conventional one-bond-flip mechanism dominates, while in frozen media (or under other forms of supramolecular constraint) the hula-twist mechanism takes over. Literature examples of photoisomerization obtained under confined conditions have been critically reviewed, the applicability of HT has been examined, and new systems unambiguously testing this volume-conserving process are proposed.
Topics: Isomerism; Photochemistry; Polyenes; Proteins
PubMed: 11456473
DOI: 10.1021/ar000165c -
The Journal of Physical and Colloid... Mar 1948
Topics: Aldehydes; Photochemistry
PubMed: 18904935
DOI: 10.1021/j150459a013 -
Philosophical Transactions. Series A,... Apr 2007The Sun provides approximately 100,000 terawatts to the Earth which is about 10000 times more than the present rate of the world's present energy consumption.... (Review)
Review
The Sun provides approximately 100,000 terawatts to the Earth which is about 10000 times more than the present rate of the world's present energy consumption. Photovoltaic cells are being increasingly used to tap into this huge resource and will play a key role in future sustainable energy systems. So far, solid-state junction devices, usually made of silicon, crystalline or amorphous, and profiting from the experience and material availability resulting from the semiconductor industry, have dominated photovoltaic solar energy converters. These systems have by now attained a mature state serving a rapidly growing market, expected to rise to 300 GW by 2030. However, the cost of photovoltaic electricity production is still too high to be competitive with nuclear or fossil energy. Thin film photovoltaic cells made of CuInSe or CdTe are being increasingly employed along with amorphous silicon. The recently discovered cells based on mesoscopic inorganic or organic semiconductors commonly referred to as 'bulk' junctions due to their three-dimensional structure are very attractive alternatives which offer the prospect of very low cost fabrication. The prototype of this family of devices is the dye-sensitized solar cell (DSC), which accomplishes the optical absorption and the charge separation processes by the association of a sensitizer as light-absorbing material with a wide band gap semiconductor of mesoporous or nanocrystalline morphology. Research is booming also in the area of third generation photovoltaic cells where multi-junction devices and a recent breakthrough concerning multiple carrier generation in quantum dot absorbers offer promising perspectives.
Topics: Conservation of Energy Resources; Electricity; Electrochemistry; Forecasting; Internationality; Photochemistry; Power Plants; Solar Energy; Technology Assessment, Biomedical; Transducers
PubMed: 17272237
DOI: 10.1098/rsta.2006.1963 -
The Journal of Physical Chemistry. A Jun 2015The structure, infrared spectrum, and photochemistry of 5-hydroxyquinoline (5HQ) were studied by matrix isolation infrared spectroscopy, complemented by theoretical...
The structure, infrared spectrum, and photochemistry of 5-hydroxyquinoline (5HQ) were studied by matrix isolation infrared spectroscopy, complemented by theoretical calculations performed at the DFT(B3LYP)/6-311++G(d,p) level of approximation. According to the calculations, the trans conformer of 5HQ (with the OH group pointing to the opposite direction of the pyridine ring of the molecule) is more stable than the cis form (by ∼8.8 kJ mol(-1)). The main factors determining the relative stability of the two conformers were rationalized through natural bond orbital (NBO) and charge density analyses. The compound was trapped in solid nitrogen at 10 K, and its infrared spectra registered and interpreted, showing the sole presence in the matrix of the more stable trans conformer. Broadband in situ UV irradiations (λ ≥ 288 nm and λ ≥ 235 nm) allowed for the observation of different chemical transformations, which started by excitation to the S1 state of 5HQ, followed by homolytic cleavage of the O-H bond, and subsequent reattachment of the H atom to the 5HQ radical to form quinolin-5(6H)-one and quinolin-5(8H)-one. The first of these two quinolinones was found to convert to open-ring isomeric ketenes, especially when irradiation was performed at higher energy, whereas the second is rather stable under the used experimental conditions. As a whole, the observed photochemistry of matrix-isolated 5HQ closely matches those previously reported for phenol and thiophenol. A detailed mechanistic interpretation for the observed photochemical processes is here proposed, which received support from time-dependent DFT calculations.
Topics: Hydroxyquinolines; Molecular Conformation; Photochemistry; Spectrophotometry, Infrared; Ultraviolet Rays
PubMed: 26024730
DOI: 10.1021/acs.jpca.5b03942