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1.
Tijdschr Psychiatr ; 66(3): 161-164, 2024.
Article in Dutch | MEDLINE | ID: mdl-38650514

ABSTRACT

BACKGROUND: ChatGPT is increasingly used in various sectors, from lawyers to copywriters. However, its implementation in Mental Health Care (MHC) is still largely uncharted territory, both administratively and therapeutically. AIM: This essay provides an informed view on the practical implementation of ChatGPT in MHC, paying special attention to both administrative and therapeutic applications, as well as identifying some challenges. METHOD: Through exploratory contemplation and literature research, the use of ChatGPT in MHC is depicted, considering the applications and limitations of the technology. RESULTS: ChatGPT can be effectively used for administrative tasks such as generating letters and documents. Additionally, it offers potential in treatments, provided it is carefully implemented and evaluated. Practical examples illustrate the versatility of ChatGPT in MHC. CONCLUSION: ChatGPT has the potential to significantly transform MHC, from streamlining administrative tasks to enhancing therapeutic contact. Aspects such as privacy and information accuracy should be central in its implementation. While current scientific evidence is still quite limited, ChatGPT already offers possibilities that should now be utilized by healthcare professionals. It is crucial that therapists form an opinion about ChatGPT, and institutions should be willing to invest in this innovative technology.


Subject(s)
Mental Health Services , Humans , Mental Health Services/standards , Mental Health Services/organization & administration , Mental Disorders/therapy
2.
Neth Heart J ; 30(9): 423-428, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35380417

ABSTRACT

AIM: To provide insight into the basic characteristics of decision making in the treatment of symptomatic severe aortic stenosis (SSAS) in Dutch heart centres with specific emphasis on the evaluation of frailty, cognition, nutritional status and physical functioning/functionality in (instrumental) activities of daily living [(I)ADL]. METHODS: A questionnaire was used that is based on the European and American guidelines for SSAS treatment. The survey was administered to physicians and non-physicians in Dutch heart centres involved in the decision-making pathway for SSAS treatment. RESULTS: All 16 Dutch heart centres participated. Before a patient case is discussed by the heart team, heart centres rarely request data from the referring hospital regarding patients' functionality (n = 5), frailty scores (n = 0) and geriatric consultation (n = 1) as a standard procedure. Most heart centres 'often to always' do their own screening for frailty (n = 10), cognition/mood (n = 9), nutritional status (n = 10) and physical functioning/functionality in (I)ADL (n = 10). During heart team meetings data are 'sometimes to regularly' available regarding frailty (n = 5), cognition/mood (n = 11), nutritional status (n = 8) and physical functioning/functionality in (I)ADL (n = 10). After assessment in the outpatient clinic patient cases are re-discussed 'sometimes to regularly' in heart team meetings (n = 10). CONCLUSIONS: Dutch heart centres make an effort to evaluate frailty, cognition, nutritional status and physical functioning/functionality in (I)ADL for decision making regarding SSAS treatment. However, these patient data are not routinely requested from the referring hospital and are not always available for heart team meetings. Incorporation of these important data in a structured manner early in the decision-making process may provide additional useful information for decision making in the heart team meeting.

3.
J Crit Care ; 68: 22-30, 2022 04.
Article in English | MEDLINE | ID: mdl-34856490

ABSTRACT

INTRODUCTION: Evidence on physical and psychological well-being of in-hospital cardiac arrest (IHCA) survivors is scarce. The aim of this study is to describe long-term health-related quality of life (HRQoL), functional independence and psychological distress 3 and 12 months post-IHCA. METHODS: A multicenter prospective cohort study in 25 hospitals between January 2017 - May 2018. Adult IHCA survivors were included. HRQoL (EQ-5D-5L, SF-12), psychological distress (HADS, CSI) and functional independence (mRS) were assessed at 3 and 12 months post-IHCA. RESULTS: At 3-month follow-up 136 of 212 survivors responded to the questionnaire and at 12 months 110 of 198 responded. The median (IQR) EQ-utility Index score was 0.77 (0.65-0.87) at 3 months and 0.81 (0.70-0.91) at 12 months. At 3 months, patients reported a median SF-12 (IQR) physical component scale (PCS) of 38.9 (32.8-46.5) and mental component scale (MCS) of 43.5 (34.0-39.7) and at 12 months a PCS of 43.1 (34.6-52.3) and MCS 46.9 (38.5-54.5). DISCUSSION: Using various tools most IHCA survivors report an acceptable HRQoL and a substantial part experiences lower HRQoL compared to population norms. Our data suggest that younger (male) patients and those with poor functional status prior to admission are at highest risk of impaired HRQoL.


Subject(s)
Heart Arrest , Quality of Life , Adult , Hospitals , Humans , Male , Prospective Studies , Surveys and Questionnaires , Survivors/psychology
4.
Neth Heart J ; 26(11): 540-551, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30232783

ABSTRACT

OBJECTIVE: The EuroSCORE I was one of the most frequently used pre-operative risk models in cardiac surgery. In 2011 it was replaced by its successor the EuroSCORE II. This study aims to validate the EuroSCORE II and to compare its performance with the EuroSCORE I in a Dutch hospital. METHODS: The EuroSCORE II was prospectively validated in 2,296 consecutive cardiac surgery patients between 1 April 2012 and 1 January 2014. Receiver operating characteristic curves on in-hospital mortality were plotted for EuroSCORE I and EuroSCORE II, and the area under the curve was calculated to assess discriminative power. Calibration was assessed by comparing observed versus expected mortality. Additionally, analyses were performed in which we stratified for type of surgery and for elective versus emergency surgery. RESULTS: The observed mortality was 2.4% (55 patients). The discriminative power of the EuroSCORE II surpassed that of the EuroSCORE I (area under the curve EuroSCORE II 0.871, 95% confidence interval (CI) 0.832-0.911; area under the curve additive EuroSCORE I 0.840, CI 0.798-0.882; area under the curve logistic EuroSCORE I 0.761, CI 0.695-0.828). Both the additive and the logistic EuroSCORE I overestimated mortality (predictive mortality additive EuroSCORE I median 5.0%, inter-quartile range 3.0-8.0%; logistic EuroSCORE I 10.7%, inter-quartile range 5.8-13.9), while the EuroSCORE II underestimated mortality (median 1.6%, inter-quartile range 1.0-3.5). In most stratified analyses the EuroSCORE II performed better. CONCLUSION: Our results show that the EuroSCORE II produces a valid risk prediction and outperforms the EuroSCORE I in elective cardiac surgery patients.

5.
Phys Rev Lett ; 121(25): 258001, 2018 Dec 21.
Article in English | MEDLINE | ID: mdl-30608787

ABSTRACT

Vacancies in simple cubic crystals of hard cubes are known to delocalize over one-dimensional chains of several lattice sites. Here, we use computer simulations to examine the structure and dynamics of vacancies in simple cubic crystals formed by hard cubes, right rhombic prisms (slanted cubes), truncated cubes, and particles interacting via a soft isotropic pair potential. We show that these vacancies form a vacancy analog of the crowdion interstitial, generating a strain field which follows a soliton solution of the sine-Gordon equation, and diffusing via a persistent random walk. Surprisingly, we find that the structure of these "voidions" is not significantly affected by changes in density, vacancy concentration, and even particle interaction. We explain this structure quantitatively using a one-dimensional model that includes the free-energy barrier particles have to overcome to slide between lattice sites and the effective pair interaction along this line. We argue that voidions are a robust phenomenon in systems of repulsive particles forming simple cubic crystals.

6.
J Chem Phys ; 147(12): 124501, 2017 Sep 28.
Article in English | MEDLINE | ID: mdl-28964042

ABSTRACT

We use computer simulations to study the phase behaviour for hard, right rhombic prisms as a function of the angle of their rhombic face (the "slant" angle). More specifically, using a combination of event-driven molecular dynamics simulations, Monte Carlo simulations, and free-energy calculations, we determine and characterize the equilibrium phases formed by these particles for various slant angles and densities. Surprisingly, we find that the equilibrium crystal structure for a large range of slant angles and densities is the simple cubic crystal-despite the fact that the particles do not have cubic symmetry. Moreover, we find that the equilibrium vacancy concentration in this simple cubic phase is extremely high and depends only on the packing fraction and not the particle shape. At higher densities, a rhombic crystal appears as the equilibrium phase. We summarize the phase behaviour of this system by drawing a phase diagram in the slant angle-packing fraction plane.

7.
Soft Matter ; 12(25): 5630-5, 2016 Jul 07.
Article in English | MEDLINE | ID: mdl-27257054

ABSTRACT

Using computer simulations we explore how grain boundaries can be removed from three-dimensional colloidal crystals by doping with a small fraction of active colloids. We show that for sufficient self-propulsion, the system is driven into a crystal-fluid coexistence. In this phase separated regime, the active dopants become mobile and spontaneously gather at the grain boundaries. The resulting surface melting and recrystallization of domains result in the motion of the grain boundaries over time and lead to the formation of a large single crystal. However, when the self-propulsion is too low to cause a phase separation, we observe no significant enhancement of grain growth.

8.
Soft Matter ; 12(14): 3406-11, 2016 Apr 14.
Article in English | MEDLINE | ID: mdl-26936131

ABSTRACT

Using simulations we explore the behaviour of two-dimensional colloidal (poly)crystals doped with active particles. We show that these active dopants can provide an elegant new route to removing grain boundaries in polycrystals. Specifically, we show that active dopants both generate and are attracted to defects, such as vacancies and interstitials, which leads to clustering of dopants at grain boundaries. The active particles both broaden and enhance the mobility of the grain boundaries, causing rapid coarsening of the crystal domains. The remaining defects recrystallize upon turning off the activity of the dopants, resulting in a large-scale single-domain crystal.

9.
Soft Matter ; 11(48): 9385-92, 2015 Dec 28.
Article in English | MEDLINE | ID: mdl-26435265

ABSTRACT

In this paper we study a two-dimensional system of charged colloidal particles using Brownian dynamics simulations. We determine the phase diagram and investigate the dynamics of this system in the density regime where hexatic and solid phases are stable. We find that the dynamics in these phases is heterogeneous by means of the spontaneous formation and diffusion of highly mobile defects. We identify two key mechanisms associated with the areas of high mobility. The first mechanism involves the highly cooperative motion of a closed loop of particles which shift coherently along the loop until each particle has replaced the position of its predecessor in the chain. The second mechanism involves the spontaneous creation of vacancy-interstitial pairs which diffuse within the hexatic and solid phases. We further explore quantitatively the properties of the open-ended and closed rearrangement strings and find that in the crystal phase the string-size distribution can be approximately matched with a simple, random walk description of vacancies and interstitials on a lattice.

10.
Methods ; 66(2): 131-8, 2014 Mar 15.
Article in English | MEDLINE | ID: mdl-23811334

ABSTRACT

Förster resonance energy transfer (FRET) describes a physical phenomenon widely applied in biomedical research to estimate separations between biological molecules. Routinely, genetic engineering is used to incorporate spectral variants of the green fluorescent protein (GFPs), into cellular expressed proteins. The transfer efficiency or rate of energy transfer between donor and acceptor FPs is then assayed. As appreciable FRET occurs only when donors and acceptors are in close proximity (1-10nm), the presence of FRET may indicate that the engineered proteins associate as interacting species. For a homogeneous population of FRET pairs the separations between FRET donors and acceptors can be estimated from a measured FRET efficiency if it is assumed that donors and acceptors are randomly oriented and rotate extensively during their excited state (dynamic regime). Unlike typical organic fluorophores, the rotational correlation-times of FPs are typically much longer than their fluorescence lifetime; accordingly FPs are virtually static during their excited state. Thus, estimating separations between FP FRET pairs is problematic. To overcome this obstacle, we present here a simple method for estimating separations between FPs using the experimentally measured average FRET efficiency. This approach assumes that donor and acceptor fluorophores are randomly oriented, but do not rotate during their excited state (static regime). This approach utilizes a Monte-Carlo simulation generated look-up table that allows one to estimate the separation, normalized to the Förster distance, from the average FRET efficiency. Assuming a dynamic regime overestimates the separation significantly (by 10% near 0.5 and 30% near 0.75 efficiencies) compared to assuming a static regime, which is more appropriate for estimates of separations between FPs.


Subject(s)
Fluorescence Resonance Energy Transfer/methods , Algorithms , Computer Simulation , Fluorescent Dyes/chemistry , Microscopy, Fluorescence/methods , Monte Carlo Method
11.
PLoS One ; 7(11): e49593, 2012.
Article in English | MEDLINE | ID: mdl-23152925

ABSTRACT

Förster resonance energy transfer (FRET) microscopy is widely used to study protein interactions in living cells. Typically, spectral variants of the Green Fluorescent Protein (FPs) are incorporated into proteins expressed in cells, and FRET between donor and acceptor FPs is assayed. As appreciable FRET occurs only when donors and acceptors are within 10 nm of each other, the presence of FRET can be indicative of aggregation that may denote association of interacting species. By monitoring the excited-state (fluorescence) decay of the donor in the presence and absence of acceptors, dual-component decay analysis has been used to reveal the fraction of donors that are FRET positive (i.e., in aggregates)._However, control experiments using constructs containing both a donor and an acceptor FP on the same protein repeatedly indicate that a large fraction of these donors are FRET negative, thus rendering the interpretation of dual-component analysis for aggregates between separately donor-containing and acceptor-containing proteins problematic. Using Monte-Carlo simulations and analytical expressions, two possible sources for such anomalous behavior are explored: 1) conformational heterogeneity of the proteins, such that variations in the distance separating donor and acceptor FPs and/or their relative orientations persist on time-scales long in comparison with the excited-state lifetime, and 2) FP dark states.


Subject(s)
Darkness , Fluorescence Resonance Energy Transfer , Green Fluorescent Proteins/metabolism , Computer Simulation , Monte Carlo Method
13.
Ned Tijdschr Geneeskd ; 151(40): 2214-8, 2007 Oct 06.
Article in Dutch | MEDLINE | ID: mdl-17969573

ABSTRACT

A 62-year-old man was brought into the intensive care unit because of a cardiac arrest. After extensive resuscitation, including defibrillation, sinus bradycardia occurred with marked QT prolongation, followed by recurrent episodes of torsade de pointes. Hetero-anamnestic data revealed a suicide attempt with sotalol. Treatment consisted largely of temporary pacing using an external transvenous overdrive pacemaker and administration of glucagon, milrinon and norepinephrine. Eventually, the patient was discharged in good condition. A suicide attempt with sotalol is a rare intoxication with considerable morbidity and mortality. Treatment is primarily based upon counteracting the proarrhythmic effects of sotalol. However, even when therapeutic levels of this drug are used, proarrhythmic effects can occur.


Subject(s)
Heart Arrest/chemically induced , Pacemaker, Artificial , Sotalol/adverse effects , Suicide, Attempted , Tachycardia/chemically induced , Heart Arrest/therapy , Heart Rate/drug effects , Humans , Male , Middle Aged , Tachycardia/therapy
14.
Schmerz ; 21(5): 469-77; quiz 478, 2007 Oct.
Article in German | MEDLINE | ID: mdl-17828610

ABSTRACT

The etiology of fibromyalgia as a chronic disease is still unexplained. This article gives an overview of the newest treatment methods of behavioral medicine of the fibromyalgia syndrome with regard to the state of research of etiology and diagnosis of this disease. Methods such as operant conditioning, cognitive-behavioral approaches, patient education and relaxation methods are discussed.


Subject(s)
Behavior Therapy , Fibromyalgia/psychology , Fibromyalgia/therapy , Fibromyalgia/etiology , Humans , Models, Psychological , Pain/psychology
15.
Rheumatology (Oxford) ; 46(6): 1029-33, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17409134

ABSTRACT

OBJECTIVES: Nasal carriage of Staphylococcus aureus constitutes a risk factor for disease exacerbation in Wegener's granulomatosis (WG). We hypothesized that staphylococcal superantigens (SAg) are a determinant of S. aureus-related risk for disease relapse in WG. METHODS: In a retrospective longitudinal cohort study in 62 WG patients, we investigated the presence of the staphylococcal SAg genes sea, seb, sec, sed, see, tsst-1 and eta in S. aureus strains isolated from WG patients during an observation period of seven years. Subsequently, we assessed whether relapses of WG were associated with the presence of SAg-positive staphylococci. RESULTS: Of 1718 swab cultures analysed, 709 (41.2%) were S. aureus-positive. Fifty-one patients carried S. aureus, of whom 37 (72.5%) patients carried at least one SAg-positive S. aureus strain. Of the 709 S. aureus-positive cultures, 326 (46%) contained at least one SAg gene. Except for see, all assessed SAg genes were detected. sea was found most frequently, followed by sec, tsst-1 and eta and finally, by sed and seb. Using a multivariate, time-dependent Cox regression analysis we found that the presence of S. aureus was associated with relapses of WG (RR 3.2; 95% CI 1.2-8.4). The risk for relapse was modulated by the presence and type of SAg, with tsst-1 being associated with an increased risk for relapse (RR 13.3, 95% CI 4.2-42.6). CONCLUSION: The risk for relapse of WG increases with the presence of tsst-1-positive S. aureus. Eradication of tsst-1-positive S. aureus in WG may show whether disease relapses can be prevented.


Subject(s)
Bacterial Toxins/analysis , Enterotoxins/analysis , Granulomatosis with Polyangiitis/microbiology , Staphylococcal Infections/complications , Staphylococcus aureus/immunology , Superantigens/analysis , Adult , Aged , Aged, 80 and over , Bacterial Toxins/genetics , Carrier State , DNA, Bacterial/genetics , Enterotoxins/genetics , Female , Genes, Bacterial , Humans , Male , Middle Aged , Polymerase Chain Reaction/methods , Recurrence , Retrospective Studies , Risk Factors , Staphylococcus aureus/genetics , Staphylococcus aureus/pathogenicity , Superantigens/genetics
16.
Ann Rheum Dis ; 65(7): 929-35, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16269426

ABSTRACT

BACKGROUND: Inhibition of intracellular signal transduction is considered to be an interesting target for treatment in inflammation. p38 MAPK inhibitors, especially, have been developed and are now in phase II clinical trials for rheumatoid arthritis (RA). OBJECTIVE: To investigate the influence of p38 MAPK inhibition on acute phase protein (APP) production, which is dependent on both JAK/STAT and p38 MAPK pathways. METHODS: The effects of p38 MAPK inhibition on APP production and mRNA expression in four human hepatoma cell lines was investigated, after stimulation with interleukin (IL)6 and/or IL1beta or tumour necrosis factor alpha. RESULTS: Two out of four cell lines produced C reactive protein (CRP), especially after combined IL6 and IL1beta stimulation. CRP production was significantly inhibited by the p38 MAPK specific inhibitor RWJ 67657 at 1 micromol/l, which is pharmacologically relevant. Fibrinogen production was also inhibited at 1 micromol/l in all cell lines. Serum amyloid A (SAA) was produced in all four lines. In contrast with CRP, SAA production was not inhibited by RWJ 67657 at 1 micromol/l. CONCLUSION: Production and mRNA expression of CRP and fibrinogen, but not SAA production and mRNA expression, were significantly inhibited by p38 MAPK specific inhibitor in hepatoma cell lines. For p38 MAPK inhibitor treatment in RA SAA might be a better marker of disease activity than CRP and fibrinogen, because SAA is not directly affected by p38 MAPK inhibition.


Subject(s)
Acute-Phase Proteins/biosynthesis , Carcinoma, Hepatocellular/metabolism , Imidazoles/pharmacology , Liver Neoplasms/metabolism , Pyridines/pharmacology , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , Analysis of Variance , Blotting, Western/methods , C-Reactive Protein/biosynthesis , Carcinoma, Hepatocellular/drug therapy , Cell Line, Tumor , Complement C3/biosynthesis , Fibrinogen/biosynthesis , Humans , Immunization , Interleukin-1/pharmacology , Liver Neoplasms/drug therapy , MAP Kinase Signaling System/drug effects , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction , STAT3 Transcription Factor/biosynthesis , Serum Amyloid A Protein/biosynthesis , Tumor Necrosis Factor-alpha/pharmacology
17.
Biophys J ; 86(5): 3020-9, 2004 May.
Article in English | MEDLINE | ID: mdl-15111416

ABSTRACT

Fluorescence polarization measurements were used to study changes in the orientation and order of different sites on actin monomers within muscle thin filaments during weak or strong binding states with myosin subfragment-1. Ghost muscle fibers were supplemented with actin monomers specifically labeled with different fluorescent probes at Cys-10, Gln-41, Lys-61, Lys-373, Cys-374, and the nucleotide binding site. We also used fluorescent phalloidin as a probe near the filament axis. Changes in the orientation of the fluorophores depend not only on the state of acto-myosin binding but also on the location of the fluorescent probes. We observed changes in polarization (i.e., orientation) for those fluorophores attached at the sites directly involved in myosin binding (and located at high radii from the filament axis) that were contrary to the fluorophores located at the sites close to the axis of thin filament. These altered probe orientations suggest that myosin binding alters the conformation of F-actin. Strong binding by myosin heads produces changes in probe orientation that are opposite to those observed during weak binding.


Subject(s)
Actin Cytoskeleton/chemistry , Actins/chemistry , Cross-Linking Reagents/chemistry , Maleimides/chemistry , Muscles/chemistry , Myosin Subfragments/chemistry , Actins/metabolism , Adenosine Diphosphate/chemistry , Amino Acids/chemistry , Animals , Binding Sites , Biophysics/methods , Fluorescent Dyes/chemistry , Lysine/chemistry , Microscopy, Fluorescence , Muscle, Skeletal , Muscles/metabolism , Myosin Subfragments/metabolism , Myosins/chemistry , Phalloidine/chemistry , Protein Binding , Protein Structure, Tertiary , Rabbits , Spectrophotometry , Time Factors
18.
J Biotechnol ; 82(3): 181-96, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11999689

ABSTRACT

The orientation factor, which is commonly called kappa-squared, is often considered to be a nuisance because it represents a significant uncertainty in the distance obtained with the FRET technique. It is shown that this uncertainty is rather small in almost all cases of practical interest if one takes the width of a 67% confidence interval (CI) for the distance distribution as a measure of uncertainty. Kappa-squared has the potential to open up new information on orientations and rotations from time-resolved studies of donor and acceptor anisotropies. One can make sense of such data by designing matrix models for the transitions between states describing various orientations and positions of donors and acceptors in the system.


Subject(s)
Energy Transfer , Spectrometry, Fluorescence , Anisotropy
19.
J Chromatogr A ; 922(1-2): 391-7, 2001 Jul 13.
Article in English | MEDLINE | ID: mdl-11486889

ABSTRACT

The determination of the fatty acid composition (as methyl esters, FAMEs) of fats and oils and their cis/trans (CTME) distribution requires a simple, but manual and time-consuming sample preparation. The so-called BF3 method is often the preferred procedure. Because FAME/CTME analyses are encountered very frequently in the food industry, an automated, robot-based alternative is proposed which uses the sodium methylate procedure. After sample weighing and the (manual) addition of heptane (2 min), a XYZ robotic autosampler is used for all remaining work, which includes reagent addition, agitation, sample settling and the final injection into the gas chromatograph (10 min). The performance of the sodium methylate and BF3 methods are compared by analysing some 30 oil and fat samples. The novel procedure is much faster (less than 15 min versus ca. 1 h) and manual sample handling is drastically decreased. The experimental results obtained with the two methods frequently are the same, while small differences can be explained by (known) differences of the two methods in the conversion of minor oil/fat constituents, such as free fatty acids, wax esters and sterol esters. In case of FAME analyses, a hot injection is to be preferred over a cold injection. The RSDs of the peak areas were 1.5% for the major fatty acids to 11% for peaks that were just above the noise level. The detection limit were approximately 0.03%.


Subject(s)
Fats/chemistry , Fatty Acids/chemistry , Fish Oils/chemistry , Automation , Esters
20.
Biochim Biophys Acta ; 1544(1-2): 333-40, 2001 Jan 12.
Article in English | MEDLINE | ID: mdl-11341942

ABSTRACT

Surface photovoltage spectroscopy (SPS) was chosen to study the photovoltaic behavior of horseradish peroxidase (HRP), hemin and immobilized hemin (poly(NIPAAm/MBA/hemin)). Different photovoltaic behaviors were observed in these three systems. In air, similar SPS curves were found for HRP and poly(NIPAAm/MBA/hemin) with different response intensities. However, poly(NIPAAm/MBA/hemin) showed a wider changing range upon increasing the positive and negative bias to 1.0 V. The SPS of hemin showed a total different behavior when an external positive potential was applied. In vacuum, clearly different photovoltaic behaviors were found. Moreover, the response value decreased when HRP was exposed to O2, the SPS intensity was different from that in air, and could be altered by changing the external biases. On the other hand, the SPS could not be changed before and after poly(NIPAAm/MBA/hemin) was exposed to O2. These differences may result from different chemical microenvironments for hemin in HRP versus that in poly(NIPAAm/MBA/hemin). It could be concluded that H2O and O2 were important factors affecting the photovoltage response in HRP, but only H2O played this important role in poly(NIPAAm/MBA/hemin).


Subject(s)
Horseradish Peroxidase/chemistry , Molecular Mimicry , Spectrum Analysis/methods , Spectrophotometry, Ultraviolet
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