Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Roeland van Wijk is active.

Publication


Featured researches published by Roeland van Wijk.


Journal of Photochemistry and Photobiology B-biology | 1993

Light-induced photon emission by mammalian cells

Roeland van Wijk; Hans van Aken; Weiping Mei; Fritz Albert Popp

In this work, the light-induced photon emission (IPE) by suspensions of mammalian cells was examined. IPE is extremely low and for detection in a single photon counting device with a cooled EMI 9558QB photomultiplier tube was used. The mammalian cells in this study were from different tissues and different mammalian species including cat, Chinese hamster, cow, dog, human, monkey, mouse and rat. The IPE was detected in all mammalian cells tested, but was different for the various cell types, ranging from 4 to 100 photons per 10(4) cells. Although our data agree with previous studies in that the IPE of non-fibroblastic normal cells is distinct from that of malignant cells our results reveal that cells of fibroblastic origin show the highest IPE values.


Complementary Medicine Research | 2005

Multi-Site Recording and Spectral Analysis of Spontaneous Photon Emission from Human Body

Eduard P.A. Van Wijk; Roeland van Wijk

Background: In the past years, research on ultraweak photon emission (UPE) from human body has increased for isolated cells and tissues. However, there are only limited data on UPE from the whole body, in particular from the hands. Objective: To describe a protocol for the management of subjects that (1) avoids interference with light-induced longterm delayed luminescence, and (2) includes the time slots for recording photon emission. Material and Methods: The protocol was utilised for multi-site recording of 4 subjects at different times of the day and different seasons, and for one subject to complete spectral analysis of emission from different body locations. An especially selected low-noise end-window photomultiplier was utilised for the detection of ultraviolet / visible light (200-650 nm) photon emission. For multi-site recording it was manipulated in three directions in a darkroom with a very low count rate. A series of cut-off filters was used for spectral analysis of UPE. 29 body sites were selected such that the distribution in UPE could be studied as right-left symmetry, dorsal-ventral symmetry, and the ratio between the central body part and extremities. Results: Generally, the fluctuation in photon counts over the body was lower in the morning than in the afternoon. The thorax-abdomen region emitted lowest and most constantly. The upper extremities and the head region emitted most and increasingly over the day. Spectral analysis of low, intermediate and high emission from the superior frontal part of the right leg, the forehead and the palms in the sensitivity range of the photomultiplier showed the major spontaneous emission at 470-570 nm. The central palm area of hand emission showed a larger contribution of the 420-470 nm range in the spectrum of spontaneous emission from the hand in autumn/winter. The spectrum of delayed luminescence from the hand showed major emission in the same range as spontaneous emission. Conclusion: Examples of multi-site UPE recordings and spectral analysis revealed individual patterns and dynamics of spontaneous UPE over the body, and spectral differences over the body. The spectral data suggest that measurements might well provide quantitative data on the individual pattern of peroxidative and anti-oxidative processes in vivo. We expect that the measurements provide physiological information that can be useful in clinical examination.


Complementary Medicine Research | 2005

Effect of Meditation on Ultraweak Photon Emission from Hands and Forehead

Eduard P.A. Van Wijk; John Ackerman; Roeland van Wijk

Background: Various physiologic and biochemical shifts can follow meditation. Meditation has been implicated in impacting free radical activity. Ultraweak photon emission (UPE, biophoton emission) is a constituent of the metabolic processes in a living system. Spectral analysis showed the characteristics of radical reactions. Objectives: Recording and analysing photon emission in 5 subjects before, during and after meditation. Methods: UPE in 5 subjects who meditated in sitting or supine positions was recorded in a darkroom utilising a photomultiplier designed for manipulation in three directions. Results: Data indicated that UPE changes after meditation. In 1 subject with high pre-meditation values, UPE decreased during meditation and remained low in the postmeditation phase. In the other subjects, only a slight decrease in photon emission was found, but commonly a decrease was observed in the kurtosis and skewness values of the photon count distribution. A second set of data on photon emission from the hands before and after meditation was collected from 2 subjects. These data were characterised by the Fano factor, F(T), i.e. variance over mean of the number of photoelectrons observed within observation time T. All data were compared to surrogate data sets which were constructed by random shuffling of the data sets. In the pre-meditation period, F(T) increased with observation time, significantly at time windows >6 s. No such effect was found after meditation, when F(T) was in the range of the surrogate data set. Conclusions: The data support the hypothesis that human photon emission can be influenced by meditation. Data from time series recordings suggest that this non-invasive tool for monitoring radical reactions during meditation is useful to characterise the effect of meditation. Fano factor analysis demonstrated that the time series before meditation do not represent a simple Poisson process. Instead, UPE has characteristics of a fractal process, showing long-range correlations. The effect of meditation waives out this coherence phenomenon, suggesting a weaker and less ordered structure of UPE. In general, meditation seems to influence the complex interactions of oxidative and anti-oxidative reactions which regulate photon emission. The reason for the statistical changes between pre- and post-meditation measurements remains unclear and demands further examination.


PLOS ONE | 2014

Ultraweak photon emission as a non-invasive health assessment: A systematic review

John A. Ives; Eduard van Wijk; Namuun Bat; Cindy Crawford; Avi Walter; Wayne B. Jonas; Roeland van Wijk; Jan van der Greef

We conducted a systematic review (SR) of the peer reviewed scientific literature on ultraweak photon emissions (UPE) from humans. The question was: Can ultraweak photon emissions from humans be used as a non-invasive health assessment? A systematic search was conducted across eight relevant databases: PubMed/MEDLINE, BIOSIS, CINAHL, PSYCHINFO, All of Cochrane EBM databases, GIDEON, DoD Biomedical Research, and clinicaltrials.gov from database inception to October 2011. Of the 1315 studies captured by the search strategy, 56 met the inclusion criteria, out of which 1 was a RCT, 27 were CCT, and 28 were observational and descriptive studies. There were no systematic reviews/meta-analyses that fit the inclusion criteria. In this report, the authors provide an assessment of the quality of the RCT included; describe the characteristics of all the included studies, the outcomes assessed, and the effectiveness of photon emission as a potential health assessment tool. This report demonstrates that the peer reviewed literature on UPE and human UPE measurement in particular is surprisingly large. Most of the human UPE literature is of good to high quality based on our systematic evaluation. However, an evaluation tool for systematically evaluating this type of “bio-evaluation” methodology is not currently available and would be worth developing. Publications in the peer reviewed literature over the last 50 years demonstrate that the use of “off-the-shelf” technologies and well described methodologies for the detection of human photon emissions are being used on a regular basis in medical and research settings. The overall quality of this literature is good and the use of this approach for determining inflammatory and oxidative states of patients indicate the growing use and value of this approach as both a medical and research tool.


Journal of Alternative and Complementary Medicine | 2008

Differential Effects of Relaxation Techniques on Ultraweak Photon Emission

Eduard P.A. Van Wijk; Rainer Lüdtke; Roeland van Wijk

BACKGROUNDnEvidence has accumulated favoring the possible role of oxidative stress in the pathogenesis of many chronic diseases. Meditation is utilized as an adjunct to conventional medical treatment for several clinical conditions. A few studies suggest a role of long-term meditation in the control of the free-radical metabolism. Many techniques for recording reactive oxygen species (ROS) have been made available. However, most are invasive and none are applicable to all conditions. Attention has recently been drawn to spontaneous ultraweak photon emission (UPE). However, the application of this method in meditation studies is very limited.nnnOBJECTIVEnThe present study recorded spontaneous UPE at multiple anatomic locations of subjects with long-term experience in transcendental meditation (TM) and compared this with a group that practiced other meditation techniques (OMT) and with subjects having no meditation experience.nnnMETHODSnThe study examined the anatomic pattern of UPE of 20 subjects practicing TM, compared to 20 subjects practicing OMT, and 20 control subjects with no experience in meditation. Subjects were men who were reported to be healthy and nonsmokers. Meditation was not practiced on the day prior to recording. UPE was recorded in a dark room, using a highly sensitive, cooled photomultiplier system designed for manipulation in three directions. The protocol for the multisite registration of UPE included recording 12 anatomic locations, including the anterior torso, head, neck, and hands.nnnRESULTSnData demonstrated emission intensities in the TM and OMT groups that were 27% and 17% lower, respectively, compared to the control group. The decrease was recorded at all anatomic locations. The percent emission contribution of each location to total emission was very similar for the three groups.nnnCONCLUSIONSnData supported the hypothesis that persistent meditation resulted in decreased UPE. However, the determination of oxidation levels as the source of group differences needs to be verified further to confirm our hypothesis.


PLOS ONE | 2013

Imaging of ultra-weak photon emission in a rheumatoid arthritis mouse model

Eduard van Wijk; Masaki Kobayashi; Roeland van Wijk; Jan van der Greef

Ultra-weak photon emission (UPE) of a living system received scientific attention because of its potential for monitoring increased levels of reactive oxygen species (ROS) in the pathogenesis of rheumatoid arthritis (RA). In this study, a highly sensitive cryogenic charge-coupled device (CCD) camera was used to monitor in a RA mouse model the photon emission both without and with luminol. For that purpose, arthritis was induced in mice utilizing a repeated co-administration of type II collagen with lipopolysaccharide. Quantitative imaging of ultra-weak photon emission of the front and back paws of the animals was initiated 70 days after the first injection. All of the animals were measured once without luminol and once again immediately after luminol injection. Data illustrated a higher UPE intensity after initiating arthritis by CII-injection of the animals. The increase in UPE intensity was measured with and without using luminol indicating that this imaging technology may be useful for the future study of human RA.


Journal of Photochemistry and Photobiology B-biology | 2013

Attributes characterizing spontaneous ultra-weak photon signals of human subjects.

Rajendra P. Bajpai; Eduard van Wijk; Roeland van Wijk; Jan van der Greef

Sixty visible range photon signals spontaneously emitted from the dorsal side of both hands of fifteen human subjects are analyzed with the aim of finding their attributes. The signals are of 30 min duration and detected in bins of 50 ms by two synchronized photo multipliers sensitive in the range (290-630 nm). Each signal is a time series of 36,000 elements. The attributes of its signal are determined from the statistical properties of time series. The mean and variance of time series determine the attributes signal strength and intercept (p₀) and slope (p₁) of the Fano Factor curve. The photon count distribution of the time series determines squeezed state parameters |α|, r, θ and ϕ, squeezed state index (SSI), and sum of the squares of residue (SSR). The correlation between simultaneously detected signals determines intercept (c₀) and slope (c₁) of their correlation curve. The variability of attributes is studied by calculating them in smaller intervals covering the entire signal. The profile of attribute at 12 sites in a subject is more informative and biologically relevant.


Journal of Photochemistry and Photobiology B-biology | 2014

Towards whole-body ultra-weak photon counting and imaging with a focus on human beings: A review

Roeland van Wijk; Eduard P.A. Van Wijk; Herman van Wietmarschen; Jan van der Greef

For decades, the relationship between ultra-weak photon emission (UPE) and the health state of the body is being studied. With the advent of systems biology, attention shifted from the association between UPE and reactive oxygen species towards UPE as a reflection of changed metabolic networks. Essential for this shift in thinking is the development of novel photon count statistical methods that more reflect the dynamics of the systems organization. Additionally, efforts to combine and correlate UPE data with other types of measurements such as metabolomics be key to understand the complexity of the human body. This review describes the history and developments in the area of human UPE research from a technical - methodological perspective, an experimental perspective and a theoretical perspective. There is ample evidence that human UPE research will allow a better understanding of the body as a complex dynamical system. The future lies in the further development of an integrated UPE and metabolomics platform for a personalized monitoring of changes of the system towards health or disease.


Journal of Acupuncture and Meridian Studies | 2010

Human Ultraweak Photon Emission and the Yin Yang Concept of Chinese Medicine

Roeland van Wijk; Jan van der Greef; Eduard van Wijk

Abstract The relationship between connective tissue and meridian function is discussed in terms of energy transmission. The network of hydrogen-bonded water molecules interspersed within the collagen fibrillar matrix is especially significant for both the sensitivity of connective tissue to weak signals of mechanical pressure, heat, or electricity and the electrical intercommunication that may correlate with the meridian acupuncture system. Special electromagnetic properties of connective tissue have similar collective properties of ultraweak photon emission. A relationship between ultraweak photon emission and yin yang dynamics is based on three types of ultraweak photon emission studies, focusing on diurnal and annual dynamics, diseased states, and acupuncture points. A novel concept explains the functional (health) integrity of physiologic systems in relation to the left-right balance in ultraweak photon emission by pointing to, (1) balanced corticoneuromusculoskeletal activities and triboluminescent aspects of ultraweak photon emission by skeletal structures, and (2) local fine-tuning in oxygen supply and the formation of radical oxygen species. This approach offers testable hypotheses for further validation utilizing a combination of human photon recording techniques and specialized metabolomics for the estimation of organ-specific oxidative states.


Journal of Photochemistry and Photobiology B-biology | 2016

Effects of growth altitude on chemical constituents and delayed luminescence properties in medicinal rhubarb

Mengmeng Sun; Li Li; Mei Wang; Eduard van Wijk; Min He; Roeland van Wijk; Slavik Koval; Thomas Hankemeier; Jan van der Greef; Shengli Wei

To improve the quality control of herbal drugs, there has been a major shift from evaluating individual chemicals to evaluating multiple-constituent chemicals, given the multi-pharmacology nature of herbal drugs. Therefore, rapid, systematic assays are needed in order to assess the quality of medicinal herbs using a comprehensive, integrated approach. Light-induced delayed luminescence (DL) is used to measure decaying long-term ultra-weak photon emissions following excitation with light. DL is considered to be a sensitive indicator for characterizing the properties of biological systems and herbal medicines with various therapeutic properties. The aim of this study was to examine the feasibility of using DL as a novel quality-assessment tool using rhubarb material as a model system, and to establish the correlation between DL parameters and the chemical constituents of rhubarb. Raw roots and rhizomes were collected from rhubarb (Rheum palmatum L.) at various elevations in western China. HPLC analysis was used to identify fourteen bioactive constituents. Five DL parameters were calculated from the DL decay curves of the rhubarb samples. Statistical tools, including principal component analysis, were used to classify the rhubarb samples using data obtained using two different assays. Finally, Spearmans correlation coefficient was calculated to quantify the correlation between the bioactive compounds and corresponding DL parameters. We found that both the chemical analysis and DL measurements reflect variations in the quality of rhubarb due to environment factor. The DL parameters were correlated significantly with the bioactive chemical constituents. Our results indicate that DL is a promising tool for evaluating multiple constituents and for assessing the therapeutic properties of herbal medicines. Thus, DL may be used as part of a comprehensive system for assessing the quality and/or therapeutic properties of herbal medicines.

Collaboration


Dive into the Roeland van Wijk's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge