P. Ruoff

发表

Temperature dependency and temperature compensation in a model of yeast glycolytic oscillations.

Reinhart Heinrich, P. Ruoff, M. K. Christensen, 2003, Biophysical chemistry.

The Goodwin model: simulating the effect of light pulses on the circadian sporulation rhythm of Neurospora crassa.

P. Ruoff, M. Vinsjevik, C. Monnerjahn, 2001, Journal of theoretical biology.

The control of the controller: molecular mechanisms for robust perfect adaptation and temperature compensation.

P. Ruoff, X. Ni, T. Drengstig, 2009, Biophysical journal.

Performance of Homeostatic Controller Motifs Dealing with Perturbations of Rapid Growth and Depletion.

P. Ruoff, T. Drengstig, Gunhild Fjeld, 2017, The journal of physical chemistry. B.

BIOLOGICAL TIMING AND THE CLOCK METAPHOR: OSCILLATORY AND HOURGLASS MECHANISMS

P Ruoff, L Rensing, P. Ruoff, 2001, Chronobiology international.

The effect of integral control in oscillatory and chaotic reaction kinetic networks

Peter Ruoff, Tormod Drengstig, Kristian Thorsen, 2019, Physica D: Nonlinear Phenomena.

Circadian oscillators in eukaryotes

P. Ruoff, I. W. Jolma, O. Laerum, 2010, Wiley interdisciplinary reviews. Systems biology and medicine.

Simulating dark expressions and interactions of frq and wc-1 in the Neurospora circadian clock.

Peter Ruoff, Jay C Dunlap, P. Ruoff, 2008, Biophysical journal.

Semi-algebraic optimization of temperature compensation in a general switch-type negative feedback model of circadian clocks

Peter Ruoff, Sven Ole Aase, S. O. Aase, 2007, Journal of mathematical biology.

PER/TIM-mediated amplification, gene dosage effects and temperature compensation in an interlocking-feedback loop model of the Drosophila circadian clock.

Peter Ruoff, P. Ruoff, M. K. Christensen, 2005, Journal of theoretical biology.

The relationship between FRQ-protein stability and temperature compensation in the Neurospora circadian clock.

Peter Ruoff, Jay C Dunlap, P. Ruoff, 2005, Proceedings of the National Academy of Sciences of the United States of America.

TEMPERATURE EFFECT ON ENTRAINMENT, PHASE SHIFTING, AND AMPLITUDE OF CIRCADIAN CLOCKS AND ITS MOLECULAR BASES

Peter Ruoff, P. Ruoff, L. Rensing, 2002, Chronobiology international.

Systems biology of the modified branched Entner-Doudoroff pathway in Sulfolobus solfataricus

P. Ruoff, D. Schomburg, J. Schaber, 2017, PloS one.

The Goodwin Oscillator: On the Importance of Degradation Reactions in the Circadian Clock

P Ruoff, L Rensing, P. Ruoff, 1999, Journal of biological rhythms.

Antagonistic regulation with a unique setpoint, integral and double integral action

P. Ruoff, T. Drengstig, K. Thorsen, 2018, bioRxiv.

Determination of enolization rates and overall stoichiometry from proton NMR records of the methylmalonic acid Belousov-Zhabotinskii reaction

P. Ruoff, E. Hansen, 1989 .

Cerium-induced excitability and non-periodic behaviour in closed Belousov-Zhabotinsky systems

P. Ruoff, 1983 .

The Escherichia coli alkA Gene Is Activated to Alleviate Mutagenesis by an Oxidized Deoxynucleoside

P. Ruoff, A. Matsuda, I. Leiros, 2020, Frontiers in Microbiology.

Modeling the diversion of primary carbon flux into secondary metabolism under variable nitrate and light/dark conditions.

P. Ruoff, T. Drengstig, C. Lillo, 2016, Journal of theoretical biology.

Bioeconomic evaluation of extended season and year-round tomato production in Norway using supplemental light

C. Stanghellini, P. Ruoff, T. Persson, 2022, Agricultural Systems.

Homeostatic controllers compensating for growth and perturbations

P. Ruoff, T. Drengstig, K. Thorsen, 2018, bioRxiv.

Exploring Mechanisms of Glucose Uptake Regulation and Dilution Resistance in Growing Cancer Cells

P. Ruoff, T. Drengstig, Gunhild Fjeld, 2020, bioRxiv.

An amplified derepression controller with multisite inhibition and positive feedback

P. Ruoff, Qaiser Waheed, Gorana Drobac, 2020, bioRxiv.

Temperature adaptation of house keeping and heat shock gene expression in Neurospora crassa.

P. Ruoff, L. Rensing, T. Schroeder, 1998, Fungal genetics and biology : FG & B.

PLATINUM SENSITIVE 2 LIKE impacts growth, root morphology, seed set, and stress responses

Amr R. A. Kataya, P. Ruoff, C. Lillo, 2017, PloS one.

Kinetics and mechanism of methane hydrate formation and decomposition in liquid water : Description of hysteresis

P. Ruoff, K. Lekvam, 1997 .

Frequency switching between oscillatory homeostats and the regulation of p53

P. Ruoff, N. Nishiyama, 2019, bioRxiv.

The Organization of Controller Motifs Leading to Robust Plant Iron Homeostasis

P. Ruoff, T. Drengstig, X. Xu, 2016, PloS one.

Alleviation of C⋅C Mismatches in DNA by the Escherichia coli Fpg Protein

P. Ruoff, S. Klimašauskas, A. Klungland, 2021, Frontiers in Microbiology.

Heat Shock and Oxidative Stress-induced Exposure of Hydrophobic Protein Domains as Common Signal in the Induction ofhsp68*

U. Hobohm, P. Ruoff, L. Rensing, 2001, The Journal of Biological Chemistry.

Global structure of magnetorotationally turbulent protoplanetary discs

P. Ruoff, R. Kissmann, W. Kley, 2011, 1111.5497.

Gradient and mc scf calculations of the conformers and the formation of primary ethylene ozonide

P. Ruoff, J. Almlöf, S. Sæbø, 1981 .

Conformational analysis of primary ethylene ozonide by gradient and multiconfigurational scf calculations

P. Ruoff, J. Almlöf, S. Sæbø, 1980 .

Considerably Lower Levels of Hypocretin-1 in Cerebrospinal Fluid Is Revealed by a Novel Mass Spectrometry Method Compared with Standard Radioimmunoassay.

P. Ruoff, M. Partinen, R. Omdal, 2019, Analytical chemistry.

A basic model of calcium homeostasis in non-excitable cells

P. Ruoff, Christina H. Selstø, 2022, bioRxiv.

The Goodwin Oscillator and its Legacy

P. Ruoff, D. Gonze, 2020, Acta Biotheoretica.

The complete UV–visible photoluminescence spectrum of aqueous Ce(III)

P. Ruoff, A. Bjørnstad, Monica Jakobsen, 1998 .

The complete UV-visible photoluminescence spectrum of

P. Ruoff, A. Bjørnstad, Monica Jakobsen, 1998 .

Influence of Oxygen and Organic Substrate on Oscillations and Autocatalysis in the Belousov-Zhabotinsky Reaction

P. Ruoff, L. Treindl, Per Olav Kvernberg, 1997 .

Belousov-Zhabotinsky oscillations during the chemical or electrochemical generation of Ag+ ions

P. Ruoff, T. Hemmingsen, L. Treindl, 1997 .

Oxidation of Methylmalonic Acid by Cerium(IV). Evidence for Parallel Reaction Pathways

P. Ruoff, E. Hansen, B. Pedersen, 1997 .

Photoluminescence in the cerium-ion catalyzed Belousov-Zhabotinsky reaction

P. Ruoff, 1994 .

Bromine hydrolysis control and two consecutive oscillatory domains in closed, cerium-catalyzed glyoxylic acid Belousov-Zhabotinsky systems

P. Ruoff, E. Hansen, E. Kőrös, 1987 .

An amplified Oregonator model simulating alternative excitabilities, transitions in types of oscillations, and temporary bistability in a closed system

R. M. Noyes, P. Ruoff, 1986 .

Variable setpoint as a relaxing component in physiological control

Peter Ruoff, Tormod Drengstig, Kristian Thorsen, 2017, Physiological reports.

Circadian rhythms and protein turnover: The effect of temperature on the period lengths of clock mutants simulated by the Goodwin oscillator

P. Ruoff, L. Rensing, S. Mohsenzadeh, 1996, Die Naturwissenschaften.

Robust adaptation and homeostasis by autocatalysis.

T Drengstig, X Y Ni, K Thorsen, 2012, The journal of physical chemistry. B.

Biological switches and clocks

Reka Albert, Peter Ruoff, Albert Goldbeter, 2008, Journal of The Royal Society Interface.

pH HOMEOSTASIS OF THE CIRCADIAN SPORULATION RHYTHM IN CLOCK MUTANTS OF NEUROSPORA CRASSA

P. Ruoff, M. Vinsjevik, Amrollah Behzadi, 2000, Chronobiology international.

Detection of small bioactive peptides from Atlantic herring (Clupea harengus L.)

P. Ruoff, F. Provan, M. Sivertsvik, 2012, Peptides.

How bromate oscillators are controlled

Peter Ruoff, P. Ruoff, E. Koros, 1988 .

Temperature-Compensation in Biological Clocks: Models and Experiments

P. Ruoff, 2004 .

Timing‐Mechanismen in der Natur: Biologische Uhren

P. Ruoff, L. Rensing, Ulf Meyer-Grahle, 2001 .

Effect of temperature in cerium-ion-catalyzed bromate-driven oscillators

P. Ruoff, G. Nagy, E. Koros, 1996 .

Phase response behaviors of different oscillatory states in the Belousov–Zhabotinsky reaction

R. M. Noyes, P. Ruoff, 1988 .

DOPA Homeostasis by Dopamine: A Control-Theoretic View

P. Ruoff, R. Kleppe, Qaiser Waheed, 2021, International journal of molecular sciences.

Temperature and nitrogen effects on regulators and products of the flavonoid pathway: experimental and kinetic model studies.

Peter Ruoff, Trond Løvdal, Michel Verheul, 2009, Plant, cell & environment.

Temperature compensation through systems biology

Peter Ruoff, H. Westerhoff, P. Ruoff, 2007, The FEBS journal.

Kinetics of the Crosslinking of Polyacrylamide with Cr(III). Analysis of Possible Mechanisms

P. Ruoff, T. Klaveness, 1994 .

Excision of uracil from DNA by hSMUG1 includes strand incision and processing

P. Ruoff, X. Xu, F. Kirpekar, 2018, Nucleic acids research.

Excitability in a closed stirred Belousov—Zhabotinskii system

Peter Ruoff, P. Ruoff, 1982 .

A rapid method for preparation of the cerebrospinal fluid proteome

P. Ruoff, R. Omdal, C. Brede, 2015, Proteomics.

Kinetics and mechanism of the cerium(IV) oxidation of methylmalonic acid in sulfuric acid

P. Ruoff, G. Névdal, 1989 .

Harmonic oscillations in homeostatic controllers: Dynamics of the p53 regulatory system.

Peter Ruoff, Xiao Yu Ni, P. Ruoff, 2010, Biophysical journal.

How can yeast cells decide between three activated MAP kinase pathways? A model approach.

P. Ruoff, L. Rensing, 2009, Journal of theoretical biology.

Personalized Medicine to Improve Treatment of Dopa-Responsive Dystonia—A Focus on Tyrosine Hydroxylase Deficiency

P. Ruoff, J. Haavik, Aurora Martínez, 2021, Journal of personalized medicine.

Temperature compensation of the circadian period length--a special case among general homeostatic mechanisms of gene expression?

P. Ruoff, L. Rensing, U. Meyer, 1997, Chronobiology international.

microRNAs AS PROGNOSTICATORS IN BREAST CANCER A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR MASTER PROGRAM IN BIOLOGICAL CHEMISTRY BY SAGAR KAFLE

P. Ruoff, S. Kafle, E. Janssen, 2015 .

DIURNAL EXPRESSION OF CLOCK GENES IN PINEAL GLAND AND BRAIN AND PLASMA LEVELS OF MELATONIN AND CORTISOL IN ATLANTIC SALMON PARR AND SMOLTS

P. Ruoff, Tien‐sheng Huang, P. Fjelldal, 2010, Chronobiology international.

EFFECT OF CONTINUOUS LIGHT ON DAILY LEVELS OF PLASMA MELATONIN AND CORTISOL AND EXPRESSION OF CLOCK GENES IN PINEAL GLAND, BRAIN, AND LIVER IN ATLANTIC SALMON POSTSMOLTS

P. Ruoff, Tien‐sheng Huang, P. Fjelldal, 2010, Chronobiology international.

Lithium differentially affects clock gene expression in serum-shocked NIH-3T3 cells

Ivar Heuch, P. Ruoff, V. Steen, 2011, Journal of psychopharmacology.

Opposite-base dependent excision of 5-formyluracil from DNA by hSMUG1

P. Ruoff, A. Matsuda, I. Leiros, 2009, International journal of radiation biology.

Structural basis for enzymatic excision of N1‐methyladenine and N3‐methylcytosine from DNA

P. Ruoff, N. Birkeland, I. Leiros, 2007, The EMBO journal.

A basic set of homeostatic controller motifs.

T Drengstig, X Y Ni, K Thorsen, 2012, Biophysical journal.

The Goodwin Oscillator and its Legacy

Peter Ruoff, Didier Gonze, P. Ruoff, 2020, Acta Biotheoretica.

Excision of uracil from DNA by the hyperthermophilic Afung protein is dependent on the opposite base and stimulated by heat-induced transition to a more open structure.

P. Ruoff, N. Birkeland, A. Klungland, 2001, Mutation research.

Acetic acid treatment in S. cerevisiae creates significant energy deficiency and nutrient starvation that is dependent on the activity of the mitochondrial transcriptional complex Hap2-3-4-5

S. Wölfl, P. Ruoff, Florian Heigwer, 2012, Front. Oncol..

Nutrient depletion as a key factor for manipulating gene expression and product formation in different branches of the flavonoid pathway.

P. Ruoff, C. Lillo, Unni S. Lea, 2008, Plant, cell & environment.

Kinetics of the Crosslinking of Poly(acrylamide) with Cr(III). 3. Rheological Measurements of the Gelation

P. Ruoff, T. Klaveness, J. Kolnes, 1995 .

Control theoretic properties of physiological controller motifs

Peter Ruoff, Tormod Drengstig, Kristian Thorsen, 2013, 2013 International Conference on System Science and Engineering (ICSSE).

A Nitrate-Induced frq-Less Oscillator in Neurospora crassa

P. Ruoff, M. K. Christensen, J. Dunlap, 2004, Journal of biological rhythms.

The Temperature-Compensated Goodwin Model Simulates Many Circadian Clock Properties

Peter Ruoff, P. Ruoff, L. Rensing, 1996 .

Introducing temperature‐compensation in any reaction kinetic oscillator model

Peter Ruoff, P. Ruoff, 1992 .

A minimal model of light‐induced circadian rhythms of nitrate reductase activity in leaves of barley

P. Ruoff, C. Lillo, 1984 .

New dynamic behaviors in a closed iodide-catalyzed bromate oscillator: experiments and their mechanistic interpretation

P. Ruoff, E. Koros, M. Varga, 1987 .

Phase response relationships as an analytical tool in investigating chemical oscillating reactions. I. A crucial test between Explodator and Oregonator‐type models describing the Ag+‐perturbed Belousov–Zhabotinsky reaction

P. Ruoff, 1985 .

Studying adaptation and homeostatic behaviors of kinetic networks by using MATLAB.

P. Ruoff, T. Drengstig, T. Kjosmoen, 2011, Methods in molecular biology.

Transepithelial glucose transport and Na+/K+ homeostasis in enterocytes: an integrative model.

P. Ruoff, T. Drengstig, K. Thorsen, 2014, American journal of physiology. Cell physiology.

Homeostasis at different backgrounds: The roles of overlayed feedback structures in vertebrate photoadaptation

P. Ruoff, Jonas V. Grini, Melissa Nygård, 2023, bioRxiv.

Action potential propagation and facilitation-like phenomena in the closed stirred excitable Belousov-Zhabotinsky reaction

P. Ruoff, 1983, Naturwissenschaften.

Modeling temperature compensation in chemical and biological oscillators.

Peter Ruoff, Roald Kommedal, P. Ruoff, 1997, Chronobiology international.

Antagonistic balance in the oregonator: about the possibility of temperature-compensation in the Belousov-Zhabotinsky

P. Ruoff, 1995 .

Circadian Rhythmicity by Autocatalysis

Peter Ruoff, Jennifer J. Loros, Jay C. Dunlap, 2006, PLoS Comput. Biol..

Kinetics of gas hydrate formation in w/o-emulsions the model system trichlorofluoromethane/water/non-ionic surfactant studied by means of dielectric spectroscopy

P. Ruoff, J. Sjöblom, T. Jakobsen, 1996 .

General homeostasis in period- and temperature-compensated chemical clock mutants formed by random selection conditions

P. Ruoff, 1994, Die Naturwissenschaften.

Transitions between two oscillatory states in a closed malonic acid Belousov-Zhabotinsky reaction simultaneously catalyzed by ferroin and cerium ions

P. Ruoff, S. Kolboe, C. E. Sjøgren, 1986 .

Chemical oscillations and instabilities. Part 61. Temporary bistability and unusual oscillatory behavior in a closed Belousov-Zhabotinskii reaction system

R. M. Noyes, P. Ruoff, 1985 .

Modeling the interaction between donor-derived regulatory T cells and effector T cells early after allogeneic hematopoietic stem cell transplantation

P. Ruoff, F. Miwakeichi, J. Jiménez, 2023, Biosyst..

Robust Concentration and Frequency Control in Oscillatory Homeostats

P. Ruoff, X. Ni, T. Drengstig, 2014, PloS one.

Temperature effects on circadian clocks

P. Ruoff, L. Rensing, 2004 .

Exceptionally large oxygen effect in the Belousov-Zhabotinskii reaction

R. M. Noyes, P. Ruoff, 1989 .

Hysteretic enzyme adaptation to environmental pH: change in storage pH of alkaline phosphatase leads to a pH-optimum in the opposite direction to the applied change.

P. Ruoff, Amrollah Behzadi, A. Behzadi, 1999, Biophysical chemistry.

A reaction kinetic mechanism for methane hydrate formation in liquid water

P. Ruoff, K. Lekvam, 1993 .

FRI0280 A molecular network for fatigue in primary sjÖgren’s syndrome

P. Ruoff, R. Omdal, J. T. Kvaløy, 2018, FRIDAY, 15 JUNE 2018.

Inner filter effect: Phase relationships between oscillatory fluorescence and oscillatory Ru(II) concentration in the Belousov-Zhabotinsky reaction

P. Ruoff, Gunn Marit Solli, 1995 .

Oscillations, Excitability and Stirring Effects in Closed Methylmalonic Acid Belousov-Zhabotinsky Systems

P. Ruoff, B. Schwitters, 1983 .

Excitability created by oxygen inhibition in the stirred malonic acid Belousov-Zabotinskii system

P. Ruoff, 1982 .

homeostasis in enterocytes: an integrative model

P. Ruoff, T. Drengstig, K. Thorsen, 2014 .

Life cycle assessment of tomato production for different production strategies in Norway

P. Ruoff, T. Persson, M. Verheul, 2022, Journal of Cleaner Production.

Characterization of a manganese-catalyzed bromate-driven oscillator within the proton NMR framework

P. Ruoff, E. Hansen, 1989 .

Integrating fluctuating nitrate uptake and assimilation to robust homeostasis.

Peter Ruoff, Tormod Drengstig, Yongshun Huang, 2012, Plant, cell & environment.

Interleukin-1-related activity and hypocretin-1 in cerebrospinal fluid contribute to fatigue in primary Sjögren’s syndrome

P. Ruoff, R. Omdal, C. Brede, 2019, Journal of Neuroinflammation.

Closing the circadian negative feedback loop: FRQ-dependent clearance of WC-1 from the nucleus.

P. Ruoff, C. Hong, J. Dunlap, 2008, Genes & development.

Unraveling the function of the two Entner–Doudoroff branches in the thermoacidophilic Crenarchaeon Sulfolobus solfataricus P2

M. Wagner, P. Ruoff, D. Schomburg, 2013, The FEBS journal.

Fatigue in primary Sjögren’s syndrome: A proteomic pilot study of cerebrospinal fluid

P. Ruoff, R. Omdal, C. Brede, 2019, SAGE open medicine.

Potentiometric and spectrophotometric studies of the silver bromide reaction in 1 M sulfuric acid and its relevance to silver ion perturbed bromate-driven oscillators

P. Ruoff, Jostein Vestvik, 1989 .

Simulation of bromate-driven oscillations in the presence of excess silver ions using the Oregonator model

P. Ruoff, B. Schwitters, 1986 .

Phase response relationships of the closed bromide-perturbed Belousov-Zhabotinsky reaction. Evidence of bromide control of the free oscillating state without use of a bromide-detecting device

Peter Ruoff, P. Ruoff, 1984 .

Controversial interpretations of silver(1+) perturbation of the Belousov-Zhabotinskii reaction

Peter Ruoff, Richard M. Noyes, R. M. Noyes, 1989 .

Eukaryotic Gene Prediction by Spectral Analysis and Pattern Recognition Techniques

S. O. Aase, G. Schuster, T. Eftestol, 2006, Proceedings of the 7th Nordic Signal Processing Symposium - NORSIG 2006.

SulfoSYS (Sulfolobus Systems Biology): towards a silicon cell model for the central carbohydrate metabolism of the archaeon Sulfolobus solfataricus under temperature variation.

C. Schleper, A. Manica, H. Klenk, 2009, Biochemical Society transactions.

Biological Clocks, Rhythms, and Oscillations: The Theory of Biological Timekeeping (by Daniel B. Forger)

P. Ruoff, 2018, Journal of biological rhythms.

Predicting perfect adaptation motifs in reaction kinetic networks.

Peter Ruoff, Tormod Drengstig, Hiroki R Ueda, 2008, The journal of physical chemistry. B.

Assessing the presence of female DNA on post-coital penile swabs: Relevance to the investigation of sexual assault.

P. Ruoff, R. K. Farmen, E. S. Frøyland, 2012, Journal of forensic and legal medicine.

Interleukin-1-related activity and hypocretin-1 in cerebrospinal fluid contribute to fatigue in primary Sjögren’s syndrome

P. Ruoff, R. Omdal, J. T. Kvaløy, 2019, Journal of Neuroinflammation.

Lithium Leads to an Increased FRQ Protein Stability and to a Partial Loss of Temperature Compensation in the Neurospora Circadian Clock

P. Ruoff, I. W. Jolma, Grete Falkeid, 2006, Journal of biological rhythms.

Circadian period lengths of lipid synthesis mutants (cel, chol-1) of Neurospora show defective temperature, but intact pH-compensation

P. Ruoff, Ieda Slewa, 2002, Chronobiology international.

Aase, S.O; Ruoff, P. (2008) Semi-algebraic optimization of temperature compensation in a general switch-type negative feedback model of circadian

P. Ruoff, 2013 .

The Goodwin model: simulating the effect of cycloheximide and heat shock on the sporulation rhythm of Neurospora crassa.

P Ruoff, L Rensing, P. Ruoff, 1999, Journal of theoretical biology.

Kinetics and mechanisms of catalyzed dual-E (antithetic) controllers

P. Ruoff, Huimin Zhou, Qaiser Waheed, 2021, bioRxiv.

Lithium differentially affects clock gene expression in serum-shocked NIH-3T3 cells

Ivar Heuch, P. Ruoff, V. Steen, 2011, Journal of psychopharmacology.

Computer Controlled Automated Assay for Comprehensive Studies of Enzyme Kinetic Parameters

Peter Ruoff, Stefan Wölfl, Felix Bonowski, 2010, PloS one.

Circadian oscillators in eukaryotes

P. Ruoff, I. W. Jolma, O. Laerum, 2010, Wiley interdisciplinary reviews. Systems biology and medicine.

7-28-2006 Circadian Rhythmicity by Autocatalysis

P. Ruoff, C. Hong, J. Dunlap, 2018 .

Biological Clocks, Rhythms, and Oscillations: The Theory of Biological Timekeeping (by Daniel B. Forger)

P. Ruoff, 2018, Journal of biological rhythms.

Sulfolobus Systems Biology: Cool Hot Design for Metabolic Pathways

H. Westerhoff, P. Ruoff, R. Steuer, 2012 .

The nitrate reductase circadian system. The central clock dogma contra multiple oscillatory feedback loops.

P. Ruoff, C. Meyer, C. Lillo, 2001, Plant physiology.

Evidence for increased proton dissociation in low-activity forms of dephosphorylated squash-leaf nitrate reductase.

P. Ruoff, C. Lillo, P. Ruoff, 1997, Biophysical chemistry.