As the most important skeletal component in plants, the polysaccharide cellulose is an almost inexhaustible polymeric raw material with fascinating structure and properties. Formed by the repeated connection of D-glucose building blocks, the highly functionalized, linear stiff-chain homopolymer is characterized by its hydrophilicity, chirality, biodegradability, broad chemical modifying capacity, and its formation of versatile semicrystalline fiber morphologies. In view of the considerable increase in interdisciplinary cellulose research and product development over the past decade worldwide, this paper assembles the current knowledge in the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for coatings, films, membranes, building materials, drilling techniques, pharmaceuticals, and foodstuffs. New frontiers, including environmentally friendly cellulose fiber technologies, bacterial cellulose biomaterials, and in-vitro syntheses of cellulose are highlighted together with future aims, strategies, and perspectives of cellulose research and its applications.

Cellulose: Fascinating Biopolymer and Sustainable Raw Material

基礎講座 電気泳動(Electrophoresis)

1.1 Photodynamic Therapy and Imaging
The purpose of this review is to present the current state of the role of imaging in photodynamic therapy (PDT). In order for the reader to fully appreciate the context of the discussions embodied in this article we begin with an overview of the PDT process, starting with a brief historical perspective followed by detailed discussions of specific applications of imaging in PDT. Each section starts with an overview of the specific topic and, where appropriate, ends with summary and future directions. The review closes with the authors’ perspective of the areas of future emphasis and promise. The basic premise of this review is that a combination of imaging and PDT will provide improved research and therapeutic strategies.

PDT is a photochemistry-based approach that uses a light-activatable chemical, termed a photosensitizer (PS), and light of an appropriate wavelength, to impart cytotoxicity via the generation of reactive molecular species (Figure 1a). In clinical settings, the PS is typically administered intravenously or topically, followed by illumination using a light delivery system suitable for the anatomical site being treated (Figure 1b). The time delay, often referred to as drug-light interval, between PS administration and the start of illumination with currently used PSs varies from 5 minutes to 24 hours or more depending on the specific PS and the target disease. Strictly speaking, this should be referred to as the PS-light interval, as at the concentrations typically used the PS is not a drug, but the drug-light interval terminology seems to be used fairly frequently. Typically, the useful range of wavelengths for therapeutic activation of the PS is 600 to 800 nm, to avoid interference by endogenous chromophores within the body, and yet maintain the energetics necessary for the generation of cytotoxic species (as discussed below) such as singlet oxygen (1O2). However, it is important to note that photosensitizers can also serve as fluorescence imaging agents for which activation with light in the 400nm range is often used and has been extremely useful in diagnostic imaging applications as described extensively in Section 2 of this review. The obvious limitation of short wavelength excitation is the lack of tissue penetration so that the volumes that are probed under these conditions are relatively shallow.






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Figure 1


(A) A schematic representation of PDT where PS is a photoactivatable multifunctional agent, which, upon light activation can serve as both an imaging agent and a therapeutic agent. (B) A schematic representation of the sequence of administration, localization and light activation of the PS for PDT or fluorescence imaging. Typically the PS is delivered systemically and allowed to circulate for an appropriate time interval (the “drug-light interval”), during which the PS accumulates preferentially in the target lesion(s) prior to light activation. In the idealized depiction here the PS is accumulation is shown to be entirely in the target tissue, however, even if this is not the case, light delivery confers a second layer of selectivity so that the cytotoxic effect will be generated only in regions where both drug and light are present. Upon localization of the PS, light activation will result in fluorescence emission which can be implemented for imaging applications, as well as generation cytotoxic species for therapy. In the former case light activation is achieved with a low fluence rate to generate fluorescence emission with little or no cytotoxic effect, while in the latter case a high fluence rate is used to generate a sufficient concentration of cytotoxic species to achieve biological effects.

/pdf/imaging-and-photodynamic-therapy-mechanisms-monitoring-and-76rc7acuq5.pdf

Imaging and photodynamic therapy: mechanisms, monitoring, and optimization.

D ESIGN CON SID ERATION S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 Bll/ding a Trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 Beam Steering 254 Trapping Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 T RAPPIN G TH EORY . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .. . . . . . . . . . . . ... . . . . 260 Ray-Optics Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 Electromagnetic Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 F ORCE M EASUREM EN T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 Measurement of Trap Stiffness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 Physics of Trup Stiffness Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 B�ownia,! Motion During Force Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . 272 PlcotenslOmeters 273 Other Applications of Picotensiometry .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Determinants of Trapping Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

Biological applications of optical forces

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

https://www.zora.uzh.ch/id/eprint/44154/1/Rabe1.pdf

Understanding protein adsorption phenomena at solid surfaces

Not much is known so far about the amounts of engineered nanomaterials (ENM) that are produced but this information is crucial for environmental exposure assessment. This paper provides worldwide and Europe-wide estimates for the production and use of ten different ENM (TiO2, ZnO, FeO
 x
 , AlO
 x
 , SiO2, CeO2, Ag, quantum dots, CNT, and fullerenes) based on a survey sent to companies producing and using ENM. The companies were asked about their estimate of the worldwide or regional market and not about their company-specific production, information that they would be less likely to communicate. The study focused on the actual production quantities and not the production capacities. The survey also addressed information on distribution of the produced ENM to different product categories. The results reveal that some ENM are produced in Europe in small amounts (less than 10 t/year for Ag, QDs and fullerenes). The most produced ENM is TiO2 with up to 10,000 t of worldwide production. CeO2, FeO
 x
 , AlO
 x
 , ZnO, and CNT are produced between 100 and 1000 t/year. The data for SiO2 cover the whole range from less than 10 to more than 10,000 t/year, which is indicative of problems related to the definition of this material (is pyrogenic silica considered an ENM or not?). For seven ENM we have obtained the first estimates for their distribution to different product categories, information that also forms the base for life-cycle based exposure analysis.

/pdf/industrial-production-quantities-and-uses-of-ten-engineered-qixg8ggmbs.pdf

Industrial production quantities and uses of ten engineered nanomaterials in Europe and the world

The separation of oil from oily water is an important pursuit because of increasing worldwide oil pollution. Separation by the use of materials with selective oil/water absorption is a relatively recent area of development, yet highly promising. Owing to their selective superantiwetting/superwetting properties towards water and oil, superhydrophobic/superoleophilic surfaces and underwater superoleophobic surfaces have been developed for the separation of oil/water-free mixtures and emulsions. In this Review, after a short introduction to oil/water separation, we describe the principles of materials with selective oil/water absorption and outline recent advances in oil/water separation with superwetting/superantiwetting materials, including their design, their fabrication, and models of experimental setups. Finally, we discuss the current state of this new field and point out the remaining problems and future challenges.

Oil/Water Separation with Selective Superantiwetting/Superwetting Surface Materials

Superhydrophobic and superoleophilic polyester materials are successfully prepared by one-step growth of silicone nanofilaments onto the textile via chemical vapor deposition of trichloromethylsilane. The successful growth of silicone nanofilaments is confirmed with scanning electron microscopy, energy-dispersive X-ray analysis, and investigation of the wetting behavior of water on the textile. Even microfibers deeply imbedded inside a woven material could be coated very well with the nanofilaments. The coated textile is water repellant and could only be wetted by liquids of low surface tension. The applications of the coated textile as a membrane for oil/water separation and as a bag for selective oil absorption from water are studied in detail. Owing to the superwetting properties and flexibility of the coated textile, excellent reusability, oil/water separation efficiency, and selective oil absorption capacity are observed, which make it very promising material, e.g., for practical oil absorption.

Polyester Materials with Superwetting Silicone Nanofilaments for Oil/Water Separation and Selective Oil Absorption

Superhydrophobic textile fabrics are prepared by a simple, one-step gas phase coating procedure by which a layer of polymethylsilsesquioxane nanofilaments is grown onto the individual textile fibers. A total of 11 textile fabrics made from natural and man made fibers are successfully coated and their superhydrophobic properties evaluated by the water shedding angle technique. A thorough investigation of the commercially relevant poly(ethylene terephthalate) fabric reveals an unparalleled long-term water resistance and stability of the superhydrophobic effect. Because of the special surface geometry generated by the nanoscopic, fibrous coating on the microscopic, fibrous textiles, the coated fabric remains completely dry even after two months of full immersion in water and stays superhydrophobic even after continuous rubbing with a skin simulating friction partner under significant load. Furthermore, important textile parameters such as tensile strength, color, and haptics are unaffected by the silicone nanofilament coating. For the first time, an in-depth characterization of the wetting properties, beyond simple contact angle measurements, as well as a thorough evaluation of the most important textile parameters is performed on a superhydrophobic fabric, which reveals a true potential for application.

https://www.zora.uzh.ch/id/eprint/13689/1/Zimmermann_AdvFuncMat_2008_V.pdf

Stefan Seeger

Papers

Understanding protein adsorption phenomena at solid surfaces

Industrial production quantities and uses of ten engineered nanomaterials in Europe and the world

Oil/Water Separation with Selective Superantiwetting/Superwetting Surface Materials

Polyester Materials with Superwetting Silicone Nanofilaments for Oil/Water Separation and Selective Oil Absorption

A Simple, One-Step Approach to Durable and Robust Superhydrophobic Textiles**