| 1. |
- Barany, George, et al.
(författare)
-
Poly(ethylene glycol)-containing supports for solid-phase synthesis of peptides and combinatorial organic libraries.
- 1997
-
Ingår i: Poly(ethylene glycol): Chemistry and Biological Applications, ACS Symp. Series. - Washington, DC : American Chemical Society. - 9780841235373 ; 680, s. 239-264
-
Bokkapitel (populärvet., debatt m.m.)abstract
- The choice of a polymeric support is a key factor for the success of solid-phase methods for syntheses of organic compounds and biomolecules such as peptides and oligonucleotides. Classical Merrifield solid-phase peptide synthesis, performed on low cross-linked hydrophobic polystyrene (PS) beads, sometimes suffers from sequence-dependent coupling difficulties. The concept of incorporating PEG into supports for solid-phase synthesis represents a successful approach to alleviating such problems. This chapter reviews the preparation of families of poly(ethylene glycol)-polystyrene (PEG-PS)graft as well as (highly) Cross-Linked Ethoxylate Acrylate Resin (CLEAR) supports developed in our laboratories, and demonstrates their applications to the syntheses of a wide range of targets in connection with numerous research objectives.
|
|
| 2. |
|
|
| 3. |
- Holmberg, Krister, et al.
(författare)
-
Poly(ethylene glycol) grafting as a way to prevent protein adsorption and bacterial adherence
- 1998
-
Ingår i: Mittal Festschrift on Adhesion Science and Technology. - : VSP International Science Publishers. ; , s. 443-460
-
Bokkapitel (refereegranskat)abstract
- Grafting of poly(ethylene glycol) (PEG) is an effective way of preventing adsorption of proteins and bacteria to hydrophobic surfaces. The paper discusses and compares two different routes of attaching PEG chains to surfaces: adsorption of block copolymers of ethylene oxide and propylene oxide (EO-PO block copolymers) and grafting via use of an anchoring polymer, poly(ethylene imine) (PEI). An overriding goal is to achieve a dense packing of PEG chains. The best effect in terms of protein and bacteria rejection is obtained by adsorbing a preformed copolymer of PEG grafted to PEI on a negatively charged surface. Using PEGs of molecular weight 1,500 g/mol or higher, protein adsorption is reduced to a few percent of the amount adsorbed at an untreated surface. The block copolymer adsorption route is less effective, mainly due to protein-induced desorption of the hydrophilizing agent. Bacterial adherence is also minimal when the PEI-PEG route is used. Branched PEGs are slightly less effective than linear PEGs of the same molecular weight. The difference in performance between linear and branched PEGs is discussed in terms of difference in entropy change when the hydrophilic surface-bound layer is compressed by an approaching protein. Branched PEGs, having smaller exclusion volumes and less freedom of motion, will lose less entropy on compression. The effects excerted on protein adsorption by PEG attached to a surface parallel its effect on particle mobility in electrophoresis. Similar molecular properties seem to be responsible for both protein and bacteria rejection and reduction of electrokinetic effects.
|
|
| 4. |
- Ikäheimo, Tiina M., et al.
(författare)
-
Cold Stress : Part V. Physical Agents
- 2021
-
Ingår i: Patty's Industrial Hygiene. - : Wiley. - 9780471297840 - 9780471125327 ; , s. 1-29
-
Bokkapitel (refereegranskat)abstract
- Owing to the steep temperature gradient between the warm human body and a cold environment, a potential for high heat losses prevails that may endanger heat balance and represent a threat to human health, function, and performance. Our physiological adaptive power is relatively is relatively low in the cold. Instead, humans rely on technique, organization, and protection to mitigate the effects of cold and create conditions for work that can be coped with, at least for some time. This chapter describes the physics of heat exchange between man and the cold environment. In particular, clothing is dealt with in more detail, as it is one of the most powerful and simple means of controlling body heat exchange and to preserve an optimal heat balance. When heat cannot be preserved, the body cools, starting with fingers, hands, toes, and feet. Whole-body or local cooling, and the related physiological responses, leads to decreased work performance and adverse health effects. International standards intended for ergonomics of thermal environments are available for the assessment and management of cold-related occupational effects. The chapter ends with a suggestion for a simplified risk-assessment procedure and tables with numerous examples of preventive measures for alleviation cold stress.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Troll, Valentin, et al.
(författare)
-
Pre-Teide Volcanic Activity on the Northeast Volcanic Rift Zone
- 2013
-
Ingår i: Teide Volcano. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642258923 - 9783642258930 ; , s. 75-92
-
Bokkapitel (refereegranskat)abstract
- The northeast rift zone of Tenerife (NERZ) presents a partially eroded volcanic rift that offers a superb opportunity to study the structure and evolution of oceanic rift zones. Field data, structural observations, isotopic dating, magnetic stratigraphy, and isotope geochemistry have recently become available for this rift and provide a reliable temporal framework for understanding the structural and petrological evolution of the entire rift zone. The NERZ appears to have formed in several major pulses of activity with a particularly high production rate in the Pleistocene (ca. 0.99 and 0.56 Ma). The rift underwent several episodes of flank creep and eventual catastrophic collapses driven by intense intrusive activity and gravitational adjustment. Petrologically, a variety of mafic rock types, including crystal-rich ankaramites, have been documented, with most samples isotopically typical of the “Tenerife signal”. Some of the NERZ magmas also bear witness to contamination by hydrothermally altered components of the island edifice and/or sediments. Isotope geochemistry furthermore points to the generation of the NERZ magmas from an upwelling column of mantle plume material mixed with upper asthenospheric mantle. Finally, persistent isotopic similarity through time between the NERZ and the older central edifices on Tenerife provides strong evidence for a genetic link between Tenerife’s principal volcanic episodes.
|
|
| 9. |
|
|
