scholarly journals An Ion Source for the HVEE 14C Isotope Ratio Mass Spectrometer for Biomedical Applications

Radiocarbon ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 283-288 ◽  
Author(s):  
Dirk J. W. Mous ◽  
Wim Fokker ◽  
Rein Van Den Broek ◽  
Ron Koopmans ◽  
Christopher Bronk Ramsey ◽  
...  

During the past two decades, accelerator mass spectrometry (AMS) has allowed major developments in many areas of geosciences and archaeology. In the near future, AMS should realize a similar potential in the field of biomedical research, leading ultimately to clinical applications. For such applications, the required instrument differs significantly from that presently used in the field of 14C dating. Whereas the needed accuracy and sensitivity is more than an order of magnitude less demanding than that for present state-of-the-art 14C instrumentation, the widespread acceptance of 14C AMS in biomedical research will require AMS spectrometers that are small, simple to operate and capable of handling CO2 samples. In order to satisfy these demands, HVEE has developed a compact 14C AMS spectrometer dedicated to biomedical research. The instrument consists of a compact accelerator with a footprint of 2.25 × 1.25 m and an ion source that features direct CO2 acceptance and optimal user friendliness. Having previously described the layout and design of the accelerator, we here discuss progress on the accelerator and present the design and first results of the CO2 ion source.

Author(s):  
T. L. Hayes

Biomedical applications of the scanning electron microscope (SEM) have increased in number quite rapidly over the last several years. Studies have been made of cells, whole mount tissue, sectioned tissue, particles, human chromosomes, microorganisms, dental enamel and skeletal material. Many of the advantages of using this instrument for such investigations come from its ability to produce images that are high in information content. Information about the chemical make-up of the specimen, its electrical properties and its three dimensional architecture all may be represented in such images. Since the biological system is distinctive in its chemistry and often spatially scaled to the resolving power of the SEM, these images are particularly useful in biomedical research.In any form of microscopy there are two parameters that together determine the usefulness of the image. One parameter is the size of the volume being studied or resolving power of the instrument and the other is the amount of information about this volume that is displayed in the image. Both parameters are important in describing the performance of a microscope. The light microscope image, for example, is rich in information content (chemical, spatial, living specimen, etc.) but is very limited in resolving power.


Author(s):  
R. W. Cole ◽  
J. C. Kim

In recent years, non-human primates have become indispensable as experimental animals in many fields of biomedical research. Pharmaceutical and related industries alone use about 2000,000 primates a year. Respiratory mite infestations in lungs of old world monkeys are of particular concern because the resulting tissue damage can directly effect experimental results, especially in those studies involving the cardiopulmonary system. There has been increasing documentation of primate parasitology in the past twenty years.


Author(s):  
Philippe Fragu

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.


2019 ◽  
Vol 26 (38) ◽  
pp. 6834-6850 ◽  
Author(s):  
Mohammad Omaish Ansari ◽  
Kalamegam Gauthaman ◽  
Abdurahman Essa ◽  
Sidi A. Bencherif ◽  
Adnan Memic

: Nanobiotechnology has huge potential in the field of regenerative medicine. One of the main drivers has been the development of novel nanomaterials. One developing class of materials is graphene and its derivatives recognized for their novel properties present on the nanoscale. In particular, graphene and graphene-based nanomaterials have been shown to have excellent electrical, mechanical, optical and thermal properties. Due to these unique properties coupled with the ability to tune their biocompatibility, these nanomaterials have been propelled for various applications. Most recently, these two-dimensional nanomaterials have been widely recognized for their utility in biomedical research. In this review, a brief overview of the strategies to synthesize graphene and its derivatives are discussed. Next, the biocompatibility profile of these nanomaterials as a precursor to their biomedical application is reviewed. Finally, recent applications of graphene-based nanomaterials in various biomedical fields including tissue engineering, drug and gene delivery, biosensing and bioimaging as well as other biorelated studies are highlighted.


2020 ◽  
Vol 14 ◽  
Author(s):  
Abhishek Kumar ◽  
Neeraj Masand ◽  
Vaishali M. Patil

Abstract: Breast cancer is the most common and highly heterogeneous neoplastic disease comprised of several subtypes with distinct molecular etiology and clinical behaviours. The mortality observed over the past few decades and the failure in eradicating the disease is due to the lack of specific etiology, molecular mechanisms involved in initiation and progression of breast cancer. Understanding of the molecular classes of breast cancer may also lead to new biological insights and eventually to better therapies. The promising therapeutic targets and novel anti-cancer approaches emerging from these molecular targets that could be applied clinically in the near future are being highlighted. In addition, this review discusses some of the details of current molecular classification and available chemotherapeutics


1998 ◽  
Vol 11 (1) ◽  
pp. 360-360
Author(s):  
T. Gautschy ◽  
H.W. Duerbeck ◽  
A.M. Van Genderen ◽  
S. Benetti

The peculiar outburst of the star baptized Sakurai’s Object (SO) is a conceivable example of a late He shell flash in a post-AGB object. The new source of nuclear energy forces such objects toward high luminosities and eventually low effective temperatures; they cross the HR diagram in a comparable fashion as FG Sge did in the past - i.e., they move noticeably on the HR diagram on human timescales. From monitoring campaigns of SO during the last year, first estimates of its cooling rate were derived and in particular cyclic light variability was established. We present first results from attempts to model stellar envelopes appropriate for SO. As we hypothesize the light variability to be attributable to stellar pulsations, we aim at constraining the basic stellar parameters based on stability analyses of our envelope models. Radial, nonadiabatic stability computations provided predictions of the modal content which should be observable as SO evolves. The particular components in such mode spectra of SO as they are to appear in the coming years should indeed help to constrain basic stellar parameters such as mass and luminosity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martin Gajdošík ◽  
Karl Landheer ◽  
Kelley M. Swanberg ◽  
Christoph Juchem

AbstractIn vivo magnetic resonance spectroscopy (MRS) is a powerful tool for biomedical research and clinical diagnostics, allowing for non-invasive measurement and analysis of small molecules from living tissues. However, currently available MRS processing and analytical software tools are limited in their potential for in-depth quality management, access to details of the processing stream, and user friendliness. Moreover, available MRS software focuses on selected aspects of MRS such as simulation, signal processing or analysis, necessitating the use of multiple packages and interfacing among them for biomedical applications. The freeware INSPECTOR comprises enhanced MRS data processing, simulation and analytical capabilities in a one-stop-shop solution for a wide range of biomedical research and diagnostic applications. Extensive data handling, quality management and visualization options are built in, enabling the assessment of every step of the processing chain with maximum transparency. The parameters of the processing can be flexibly chosen and tailored for the specific research problem, and extended confidence information is provided with the analysis. The INSPECTOR software stands out in its user-friendly workflow and potential for automation. In addition to convenience, the functionalities of INSPECTOR ensure rigorous and consistent data processing throughout multi-experiment and multi-center studies.


Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Traian V. Chirila

Fibroin is a fibrous protein that can be conveniently isolated from the silk cocoons produced by the larvae of Bombyx mori silk moth. In its form as a hydrogel, Bombyx mori silk fibroin (BMSF) has been employed in a variety of biomedical applications. When used as substrates for biomaterial-cells constructs in tissue engineering, the oxygen transport characteristics of the BMSF membranes have proved so far to be adequate. However, over the past three decades the BMSF hydrogels have been proposed episodically as materials for the manufacture of contact lenses, an application that depends on substantially elevated oxygen permeability. This review will show that the literature published on the oxygen permeability of BMSF is both limited and controversial. Additionally, there is no evidence that contact lenses made from BMSF have ever reached commercialization. The existing literature is discussed critically, leading to the conclusion that BMSF hydrogels are unsuitable as materials for contact lenses, while also attempting to explain the scarcity of data regarding the oxygen permeability of BMSF. To the author’s knowledge, this review covers all publications related to the topic.


1991 ◽  
Vol 17 (1-2) ◽  
pp. 145-180
Author(s):  
Evan Ackiron

Patents and other statutory types of market protections are used in the United States to promote scientific research and innovation. This incentive is especially important in research intensive fields such as the pharmaceutical industry. Unfortunately, these same protections often result in higher monopoly pricing once a successful product is brought to market. Usually this consequence is viewed as the necessary evil of an incentive system that encourages costly research and development by promising large rewards to the successful inventor. However, in the case of the AIDS drug Zidovudine (AZT), the high prices charged by the pharmaceutical company owning the drug have led to public outcry and a re-examination of government incentive systems.This Note traces the evolution of these incentive programs — the patent system, and, to a lesser extent, the orphan drug program — and details the conflicting interests involved in their development. It then demonstrates how the AZT problem brings the interest of providing inventors with incentives for risky innovative efforts into a sharp collision with the ultimate goal of such systems: ensuring that the public has access to the resulting products at a reasonable price. Finally, the Note describes how Congress and the courts have attempted to resolve these problems in the past, and how they might best try to solve the AZT problem in the near future.


1899 ◽  
Vol 45 (191) ◽  
pp. 713-724
Author(s):  
F. Ashby Elkins ◽  
Jas. Middlemass

We think it will be generally acknowledged that the problem which the treatment of noisy, destructive, and dirty patients sets to their medical officers is greatest as regards their management at night. It is then undoubtedly that noise, destructiveness, and dirty habits have the greatest chance of getting free play, and it is then that the efforts for reformation have to be greatest. If these efforts are successful considerably more than half the problem will have been solved. It is to this part of the question, viz. the supervision of such patients during the night, that we desire in this paper to direct attention. At the outset it may be stated that our proposals are not theoretical. They are the result of practical experience gained during the past four years in the Sunderland Asylum. The special arrangements we propose to describe were instituted by one of us at the opening of the institution four years ago. At first a few cases were dealt with tentatively, but, as the first results were so encouraging, the number of cases was gradually increased, until all the patients who were restless, noisy, destructive, or of dirty habits came without exception to be dealt with. The asylum, situated at Ryhope, is a small one, containing only 350 beds, and on this account, as well as because it was new, it was conveniently suited for such an experiment. It may be well before going further to describe the arrangements now in existence there. There are 175 beds for each sex, made up as follows:—45 single rooms, one fully padded, and 2 half-padded; 2 small dormitories of 7 each, 2 of 13 each, 2 of 19 each, and 2 of 26 each. In the last two there is a night attendant, and one also in one of the dormitories for 19, which is the hospital ward. There is, in addition, a head night attendant who visits the patients in these dormitories and also all the remaining patients every hour, or oftener when necessary. There are thus 4 of a night staff for 175 patients. Though this is probably a large proportion compared to most public asylums, it is not claimed as a new departure in asylum management, as we are aware that in a number of asylums the advantage of having a large night staff is fully realised and acted on. The essential feature of the arrangements at Ryhope, to which we wish to direct attention, is the selection of cases placed in dormitories under constant supervision. Of course, all epileptics and suicidal patients are placed there. But, in addition, all recent cases of whatever kind, all dirty and destructive cases, and those who sleep badly and are in consequence inclined to chatter or be noisy, are also placed under constant supervision. Looked at from the other side, all single rooms and dormitories not under constant supervision are reserved for quiet and well-behaved patients who do not require any special attention during the night. This plan has been found to work exceedingly well, and since it was organised we have never had occasion to think of adopting any other. Another testimony to its effectiveness is that those of the staff who have the actual supervision of the patients and have had experience in other asylums are unanimous in their opinion that the arrangement is a very decided improvement. This opinion, let it be observed, is not based on the ground that now their duties are lighter than they were, because, as a matter of fact, they are more onerous.


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