510 research outputs found
Mind-body interactions in breast cancer : neuroendocrine and immune aspects of acute psychological stress and psychosocial intervention in breast cancer patients
The proposition that stress plays a role in the progression of breast cancer has been a
source of inspiration for researchers to study the associations between psychological,
neuroendocrine and immune parameters. Until now a number of shldies attempted to
provide insight in the link between stress and breast cancer by correlating psychological
strcssors with baseline endocrine and immune values. There is a growing literature
supporting the notion that by using a reactivity model more reliable information can be
obtained about the organizational level of the neuroendocrine system as well as the
sensitivity of the immune system to the endocrine signals than by determining baseline
values. However, apart from shldies that examined the alterations in neuroendocrine
system and distribution and function of peripheral blood cells in breast cancer patients
in rest, data from reactivity studies are scarce.
The series of studies described in the first part of the present thesis were designed to
investigate changes in cardiovascular, endocrine and immunological values in response
to an acute stressor in breast cancer patients and to compare their responses with those
of age-matched healthy women
Information Flow through a Chaotic Channel: Prediction and Postdiction at Finite Resolution
We reconsider the persistence of information under the dynamics of the
logistic map in order to discuss communication through a nonlinear channel
where the sender can set the initial state of the system with finite
resolution, and the recipient measures it with the same accuracy. We separate
out the contributions of global phase space shrinkage and local phase space
contraction and expansion to the uncertainty in predicting and postdicting the
state of the system. Thus, we determine how the amplification parameter, the
time lag, and the resolution influence the possibility for communication. A
novel representation for real numbers is introduced that allows for a
visualization of the flow of information between scales.Comment: 14 pages, 13 figure
Challenges for Developing Rechargeable Room-Temperature Sodium Oxygen Batteries
© 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The development of high energy-density and low-cost energy storage devices requires new chemistry beyond the horizon of current state-of-the-art lithium-ion batteries. Recently, sodium/oxygen (Na/O2) batteries have attracted great attention as one possible battery type among the new generation of rechargeable batteries. They convince with superior energy density, a relatively simple cell reaction, and abundance of sodium. Research on Na/O2 batteries has progressed quickly in recent years. However, a fundamental understanding underpinning the complex chemical/electrochemical side reactions is still insufficient, and many challenges remain unsolved for real practical applications. Herein, recent achievements and remaining issues for the development of rechargeable Na/O2 batteries are summarized. The discussion focuses on cell reaction mechanisms as well as cathode materials, sodium anodes, and electrolytes as key components of this type of battery. Furthermore, perspectives for future research and technological advances of Na/O2 batteries are outlined
Alpha-foetoprotein and carcinoembryonic antigen in germ cell neoplasms.
Serum alpha-foetoprotein (AFP) and serum carcinoembryonic antigen (CEA) levels were measured, serially whenever possible, in 70 patients attending the Institute of Radiotherapy, Rotterdam, on account of testicular (65) or ovarian (4) germ cell tumours or, in one case, an endodermal sinus (yolk sac) tumour in the mediastinum. In 15 patients the disease was active; in the others it was in remission. Patients with active disease had raised serum AFP levels which correlated well with disease activity; no patient without evidence of active disease had raised serum AFP levels. None of the patients with active disease was found to have raised serum CEA levels. There was no correlation between serum AFP and CEA levels in patients with germ cell neoplasms, but good correlation between serum AFP levels and disease activity. Serum CEA levels did not correlate with disease activity, and serial determinations would therefore not be useful in monitoring progress in this group of diseases
Measuring Information Transfer
An information theoretic measure is derived that quantifies the statistical
coherence between systems evolving in time. The standard time delayed mutual
information fails to distinguish information that is actually exchanged from
shared information due to common history and input signals. In our new
approach, these influences are excluded by appropriate conditioning of
transition probabilities. The resulting transfer entropy is able to distinguish
driving and responding elements and to detect asymmetry in the coupling of
subsystems.Comment: 4 pages, 4 Figures, Revte
Geometry-dependent electrostatics near contact lines
Long-ranged electrostatic interactions in electrolytes modify their contact
angles on charged substrates in a scale and geometry dependent manner. For
angles measured at scales smaller than the typical Debye screening length, the
wetting geometry near the contact line must be explicitly considered. Using
variational and asymptotic methods, we derive new transcendental equations for
the contact angle that depend on the electrostatic potential only at the three
phase contact line. Analytic expressions are found in certain limits and
compared with predictions for contact angles measured with lower resolution. An
estimate for electrostatic contributions to {\it line} tension is also given.Comment: 3 .eps figures, 5p
Methods for measuring the behaviour of dairy cows in free stall barns
Behaviour is one of the most commonly used and sensitive indicators of animal welfare. Methods of assessing behavioural activity have changed in recent years, favouring techniques that automate monitoring and recording of animal behaviour, respect to use video recording system. The objectives of the current study were to determine the capability of electronic recording devices (HOBO Pendant G and IceTag) to measure behavioural activity of cows in comparison with video recording system. Automatic recording devices showed data of high sensitivity (Se 65 0.961) and specificity (Sp 65 0.951) for lying and standing behavioural patterns displaying predictive values close to 1.00 (PPV 65 0.966 and NPV 65 0.945). Instead, moving behavioural pattern was inadequately recorded by the IceTag device (PPV 64 0.303).
Video recording systems provide a complete view of all behaviour and also of the position of the cows in the barn, but it is often time consuming and labour-intensive. Automated measurement of laterality may improve understanding the role of this aspect of lying as an indicator of cow comfort and might be useful for assessing the welfare of dairy cattle. Data loggers accurately measured all aspect of lying behaviour, while the locomotion behaviour (walking) is not well represented. The development of these data loggers may improve the information on activity of dairy cows reducing time and labour required for monitoring of behaviour
Induction of apoptosis in human cancer cells by targeting mitochondria with gold nanoparticles
A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell death. The ability to target Au nanoparticles into mitochondria of breast cancer cells and induce apoptosis reveals an alternative application of Au nanoparticles in photothermal therapy of cancer
Phase diagram for morphological transitions of wetting films on chemically structured substrates
Using an interface displacement model we calculate the shapes of thin
liquidlike films adsorbed on flat substrates containing a chemical stripe. We
determine the entire phase diagram of morphological phase transitions in these
films as function of temperature, undersaturation, and stripe widthComment: 15 pages, RevTeX, 7 Figure
Shapes, contact angles, and line tensions of droplets on cylinders
Using an interface displacement model we calculate the shapes of
nanometer-size liquid droplets on homogeneous cylindrical surfaces. We
determine effective contact angles and line tensions, the latter defined as
excess free energies per unit length associated with the two contact lines at
the ends of the droplet. The dependences of these quantities on the cylinder
radius and on the volume of the droplets are analyzed.Comment: 26 pages, RevTeX, 10 Figure
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