Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Data Science”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources
PubMed2006

Radiographic assessment of post-retained crowns in an adult Jordanian population.

AIM: The objective of this study was to radiographically assess and compare the quality of post-retained crowns fabricated at the Dental Health Centre of the Jordan University of Science & Technology (JUST). METHODS AND MATERIALS: Study data were collected in 2002 from existing dental records for all patients receiving treatment with post-retained crowns between October, 1997 and June, 1999. The posts were assessed radiographically to evaluate various aspects of the quality of post-retained crowns. All 129 posts were fabricated in the dental school. RESULTS: The most-frequently restored teeth were the maxillary incisors (38.8%). Sixty-two percent of the posts were tapered, while 38% were parallel-sided. The mean length of the posts was 0.95 mm (SD 0.41) with a range between 0.22-2.85 mm. Caries was diagnosed radiographically in 10.8% of cases with lesions located on root surfaces in 64.3% of them, while 35.7% of lesions were within the root canal. Three posts (2.3%) were deviated from the line of the root canal in the mesio-distal plane. No evidence of root filling was found in 2.3% of the cases. In the remainder of teeth 15.5% had gutta percha extended to the radiographic apex of the tooth, while 59.7% fell 0.5-1 mm short of the radiographic apex. Gutta-percha was extruded beyond the apex in 22.5% of the teeth. Space between the end of the post and the root filling was found in 22.2%. The percentage of canals with apparently completely healthy periapical tissue was 51.2%. In the rest of the cases 34.8% had areas of radiolucency at or near the root apices and 14% demonstrated widening of the periodontal space around the root apex. Root resection had been completed in 2.3% cases. Signs of external resorption were apparent in one case (0.78%). CONCLUSION: The standards of the treatment of the endodontically treated teeth made at the dental hospital were satisfactory but could be improved by a controlled academic supervisory environment and a strict scientific approach to fixed prosthodontics within the dental school.

Adult↗
PubMedDate not supplied

[The rational coding of stomatological data].

The introduction of the computer technique in the stomatological science and practice actualized the problems of coding of stomatological information. The material presented discusses the problems of devising of optimal code system, intended for the stomatological symptomatics. An original mode for semipontional coding is proposed. Basic characteristics of the code system are described, stressing up its main advantages.

Abstracting and Indexing↗
PubMed1986

Spectral differentiation and gas chromatographic/mass spectrometric analysis of the lacrimators 2-chloroacetophenone and o-chlorobenzylidene malononitrile.

2-Chloroacetophenone (CN) and o-chlorobenzylidene malononitrile (CS) are the most common chemical agents used as lacrimators in the United States. There is a lack of complete spectral data on these compounds in the literature. Spectral data (ultraviolet, fluorescence, proton nuclear magnetic resonance, and infrared) and a gas-liquid chromatographic/mass spectrometric method are presented that differentiate and identify CN and CS. These methods and data were used to identify a forensic science specimen from an accidental intoxication.

Gas Chromatography-Mass Spectrometry↗
PubMed1987

Theoretical prerequisites for an experimental corroboration of the existence of a specialized cellular system in control of multicellular organism tissue proliferation.

A theoretical analysis of cell proliferation as a selflimiting process designed to maintain the integrity of an entire multicellular organism and based on the principles of a "hypercycle" suggests the need for the existence, starting at a certain level of multicellular organization, of a specialized system in control of tissue proliferation, a system represented by a body of cells capable of both stimulating and inhibiting the proliferation of a variety of cell types. An analysis of experimental data in different fields of the biological science points to certain T-cell populations as probable candidate for the role of cellular regulators of tissue proliferation. Using as an example the induction of murine liver regeneration by the administration of CCL4, the author demonstrates the dynamics of the formation of cells stimulating and inhibiting regeneration, which conforms well to theoretical considerations.

Animals↗
PubMed1985

The antitumor activity of oxoplatinum.

A coordination complex cis-dichlorodiamminedihydroxoplatinum (IV) (oxoplatinum) was first synthesized in the USSR by Chugaev and Khlopin in 1927 [3]. Its marked antitumor properties were revealed by one of the authors of this article at the All-Union Cancer Research Center of the Academy of Medical Sciences of the USSR. The paper gives data on the antiblastic and side effects of oxoplatinum and also on the results of pharmacokinetic studies of the drug. Particular attention was paid to the similarity and differences of biological properties of oxoplatinum and cis-dichlorodiammineplatinum(II) (DDP) which has found wide use in oncological practice. It has been established that, on principle, oxoplatinum differs from DDP in action on the body and tumors. The new drug is 10 times less toxic than DDP. Oxoplatinum has a wide spectrum of antineoplastic action resulting in marked inhibition of growth of solid and ascitic forms of transplantable tumors. The drug has a longer duration of antitumor effect after the end of the therapeutic course. An important property of oxoplatinum is its high therapeutic index. The new drug manifests high antitumor activity with different ways of its administration into the body. Oxoplatinum in therapeutic doses does not produce necrotic lesions in the kidneys. The new drug exerted no cross-resistance with DDP and the alkylating antitumor agent sarcolysin. At the present time oxoplatinum is undergoing preclinical investigation.

Animals↗
PubMed1985

Toward an experimental chiropractic: time-series designs.

If chiropractic is to develop as a clinical science, it must develop an experimental data-base. Despite numerous continuing obstacles, a growing segment of the profession is advocating chiropractic clinical trials. However, the large-scale control-group clinical-experimental designs which have most frequently been recommended are usually beyond the economic means of chiropractic institutions. Moreover, such designs are impractical in many ways for the chiropractic field-doctor who wishes to integrate the roles of scientist and practitioner. Time-series experimental (and case study) designs offer practical and economical alternatives for the DC, whether inter, solo-practitioner, or academic researcher. Several types of time-series designs are described, published examples from related health-care literature are noted, and the role of time-series research in furthering the goals of chiropractic research are reviewed. Ethical considerations in clinical research are briefly noted.

Chiropractic↗
PubMed1983

[Possibilities of the epidemiologic method and various results of a population study of schizophrenia].

Some results of the epidemiological studies on schizophrenia conducted recently by the Epidemiology Department of the Psychiatry Institute, the USSR Academy of Medical Sciences, are summed up. The principal demographic data on schizophrenia, such as its prevalence and forms as well as the pathogenetic role of the sex and age are presented. Taking the paroxysmal forms as a model, the application of the epidemiological method in investigating the course and probable prognosis of schizophrenia is reviewed in greater detail. On the basis of the material from a representative group of patients with paroxysmal schizophrenia of the 15-year duration or over (1461 patients), the basic regularities of the time course of negative and positive disturbances during remission, as well as the specific features of the shift in the clinical forms of paroxysms are demonstrated. Statistical distribution shows that in most patients, the distinctive signs of a given form of the disease course tend to remain unaltered during the whole period of the illness. Apart from reflecting the stability of patterns of the disease course, these findings support the validity of the current schizophrenia differentiation.

Age Factors↗
PubMed1993

How hyper are we? A look at hypermedia management in academic health sciences libraries.

Advances in instruction-delivery technology have a direct impact on academic media centers. New technology challenges librarians philosophically, financially, and ethically to provide access to information and instructional systems. Each institution has a unique set of circumstances governing decisions to provide access to hypermedia. If patron needs are met satisfactorily through labs outside the library, it may not be necessary for the library to incorporate hypermedia into its collection. Other library media centers may serve as a main point of access, or a substantial alternative computing resource may exist in departments or professional schools. Regardless of which route is taken, hypermedia is a viable instructional delivery system and can coexist with traditional services. Future studies on various aspects of hypermedia and multimedia management should be encouraged. Academic health sciences librarians would benefit from the study of hypermedia and multimedia collection-development policies, equipment, and personnel management. As computer networking of multimedia and image databases becomes available, it will be interesting to see the role academic health sciences libraries assume in integrating these data-bases with traditional information-delivery systems. Changing technology and instructional methods will affect budgets as well as library relationships with academic departments and computing centers.

Computer Communication Networks↗
PubMed2003

Neuroscience data and tool sharing: a legal and policy framework for neuroinformatics.

The requirements for neuroinformatics to make a significant impact on neuroscience are not simply technical--the hardware, software, and protocols for collaborative research--they also include the legal and policy frameworks within which projects operate. This is not least because the creation of large collaborative scientific databases amplifies the complicated interactions between proprietary, for-profit R&D and public "open science." In this paper, we draw on experiences from the field of genomics to examine some of the likely consequences of these interactions in neuroscience. Facilitating the widespread sharing of data and tools for neuroscientific research will accelerate the development of neuroinformatics. We propose approaches to overcome the cultural and legal barriers that have slowed these developments to date. We also draw on legal strategies employed by the Free Software community, in suggesting frameworks neuroinformatics might adopt to reinforce the role of public-science databases, and propose a mechanism for identifying and allowing "open science" uses for data whilst still permitting flexible licensing for secondary commercial research.

Computational Biology↗
PubMed2004

Conflicts of interest in medical science: peer usage, peer review and 'CoI consultancy'.

In recent years, the perception has grown that conflicts of interest are having a detrimental effect on medical science as it influences health policy and clinical practice, leading medical journals to enforce self-declaration of potential biases in the attempt to counteract or compensate for the problem. Conflict of interest (CoI) declarations have traditionally been considered inappropriate in pure science since its evaluation systems themselves constitute a mechanism for eliminating the effect of individual biases. Pure science is primarily evaluated by 'peer usage', in which scientific information is 'replicated' by being incorporated in the work of other scientists, and tested by further observation of the natural world. Over the long-term, the process works because significant biases impair the quality of science, and bad science tends to be neglected or refuted. However, scientific evaluation operates slowly over years and decades, and only a small proportion of published work is ever actually evaluated. But most of modern medical science no longer conforms to the model of pure science, and may instead be conceptualized as a system of 'applied' science having different aims and evaluation processes. The aim of applied medical science is to solve pre-specified problems, and to provide scientific information ready for implementation immediately following publication. The primary evaluation process of applied science is peer review, not peer usage. Peer review is much more rapid (with a timescale of weeks or months) and cheaper than peer usage and (consequently) has a much wider application: peer review is a prospective validation while peer usage is retrospective. Since applied science consists of incremental advances on existing knowledge achieved using established techniques, its results can usually be reliably evaluated by peer review. However, despite its considerable convenience, peer review has significant limitations related to its reliance on opinion. One major limitation of peer review has proved to be its inability to deal with conflicts of interest, especially in a 'big science' context when prestigious scientists may have similar biases, and conflicts of interest are widely shared among peer reviewers. When applied medical science has been later checked against the slower but more valid processes of peer usage, it seems that reliance on peer review may allow damaging distortions to become 'locked-in' to clinical practice and health policy for considerable periods. Scientific progress is generally underpinned by increasing specialization. Medical journals should specialize in the communication of scientific information, and they have neither the resources nor the motivation to investigate and measure conflicts of interest. Effectively dealing with the problem of conflicts of interest in applied medical science firstly requires a more explicit demarcation between the communications media of pure medical science and applied medical science. Greater specialization of these activities would then allow distinctive aims and evaluation systems to evolve with the expectation of improved performance in both pure and applied systems. In future, applied medical science should operate with an assumption of bias, with the onus of proof on applied medical scientists to facilitate the 'data transparency' necessary to validate their research. Journals of applied medical science will probably require more rigorous processes of peer review than at present, since their publications are intended to be ready for implementation. But since peer review does not adequately filter-out conflicts of interest in applied medical science, there is a need for the evolution of specialist post-publication institutional mechanisms. The suggested solution is to encourage the establishment of independent 'CoI consultancy' services, whose role would be to evaluate conflicts of interest and other biases in published applied medical science prior to their implementation. Such services would be paid-for by the groups who intend to implement applied medical research.

Conflict of Interest↗
PubMed2006

Computation of individual latent variable scores from data with multiple missingness patterns.

Latent variable models are used in biological and social sciences to investigate characteristics that are not directly measurable. The generation of individual scores of latent variables can simplify subsequent analyses. However, missing measurements in real data complicate the calculation of scores. Missing observations also result in different latent variable scores having different degrees of accuracy which should be taken into account in subsequent analyses. This manuscript presents a publicly available software tool that addresses both these problems, using as an example a dataset consisting of multiple ratings for ADHD symptomatology in children. The program computes latent variable scores with accompanying accuracy indices, under a 'user-specified' structural equation model, in data with missing data patterns. Since structural equation models encompass factor models, it can also be used for calculating factor scores. The program, documentation and a tutorial, containing worked examples and specimen input and output files, is available at http://statgen.iop.kcl.ac.uk/lsc .

Attention Deficit Disorder with Hyperactivity↗
PubMed2006

Strategic biomonitoring initiatives: moving the science forward.

Biomonitoring programs in the United States and Europe demonstrate the vast array of data that are publicly available for the evaluation of exposure trends, identification of susceptible populations, detection of emerging chemical risks, the conduct of epidemiology studies, and evaluation of risk reduction strategies. To cultivate international discussion on these issues, the ILSI Health and Environmental Sciences Institute convened a scientific session at its annual meeting in January 2006 on "Integration of Biomonitoring Exposure Data into the Risk Assessment Process." This Forum paper presents perspectives from session speakers on the biomonitoring activities of the Centers for Disease Control and Prevention, the U.S. Environmental Protection Agency, the National Research Council Committee on Human Biomonitoring for Environmental Toxicants, the German Commission on Human Biomonitoring, and the Health and Environmental Sciences Institute Biomonitoring Technical Committee. Speakers noted that better estimates of biological concentrations of substances in the tissues of human populations can be combined with other exposure indices, as well as epidemiological and toxicologic data, to improve risk estimates. With this type of combined data, the potential also exists to define exposure levels at which hazard and risk are of minimal concern. Limitations in interpreting biomonitoring data were discussed, including the need for different criteria for applying biomonitoring data for exposure assessment, risk assessment, risk management, or disease prevention purposes. As efforts and resources are expended to improve the ability to apply biomonitoring exposure data in the risk assessment process, it is equally important to communicate the significance of such data to the public.

Environmental Monitoring↗
PubMed1985

The variation of glucose tolerance in a multi racial population.

The pattern of plasma and urine sugar changes after 50g glucose load in 1900 Malaysians (522 males and 1378 females) consisting predominantly of Malays, Chinese and Indians were studied. The data were analysed using Statistical Package for Social Sciences (SPSS). The results show bimodal distribution of 120 min. plasma sugar values in the age groups 21 years and above and trimodal distribution in most groups above 40 years. The mean 120 minutes plasma sugar cut-off values for nondiabetics (ND), impaired glucose tolerance (IGT), and diabetics (DM) of 8.4 and 11.1 mmol/l respectively were close to the values recommended by the National Diabetic Data Group (NDDG). Fifty two percent of all subjects showed peaked plasma sugar values at 60 minutes (14% of them had IGT, 12% DM), 25% peaked at 30 minutes (98% of them were ND). The rest showed peaked values at 90 minutes (17%), 120 minutes (4%) and 150 minutes (2%) and from this group forty two percent were DM and 23% had IGT. Reliance on urine sugar qualitative tests could misclassify 7.3% of subjects (predominantly elderly females) with hyperglycaemia of greater than 11 mmol/l. This study shows that in the 50 g glucose tolerance test, the NDDG criteria for ND, IGT, DM is still applicable to the Malaysian population. The sampling time could be reduced to four points at 0, 60, 90, and 120 minutes. Blood analysis is the preferred method for the diagnosis of hyperglycaemia in elderly females.

Adolescent↗
PubMed2004

Cross-site comparison of gene expression data reveals high similarity.

Consistency and coherence of gene expression data across multiple sites depends on several factors such as platform (oligo, cDNA, etc.), environmental conditions at each laboratory, and data quality. The Hepatotoxicity Working Group of the International Life Sciences Institute Health and Environmental Sciences Institute consortium on the application of genomics to mechanism-based risk assessment is investigating these factors by comparing high-density gene expression data sets generated on two sets of RNA from methapyrilene (MP) experiments conducted at Abbott Laboratories and Boehringer-Ingelheim Pharmaceuticals, Inc. using a single platform (Affymetrix Rat Genome U34A GeneChip) at seven different sites. This article focuses on the evaluation of data quality and statistical models that facilitate the comparison of such data sets at the probe level. We present methods for exploring and quantitatively assessing differences in the data, with the principal goal being the generation of lists of site-insensitive genes responsive to low and high doses of MP. A combination of numerical and graphical techniques reveals important patterns and partitions of variability in the data, including the magnitude of the site effects. Although the site effects are significantly large in the analysis results, they appear to be primarily additive and therefore can be adjusted in the statistical calculations in a way that does not bias conclusions regarding treatment differences.

Animals↗
PubMed2003

Craniofacial imaging informatics and technology development.

PURPOSE: 'Craniofacial imaging informatics' refers to image and related scientific data from the dentomaxillofacial complex, and application of 'informatics techniques' (derived from disciplines such as applied mathematics, computer science and statistics) to understand and organize the information associated with the data. METHOD: Major trends in information technology determine the progress made in craniofacial imaging and informatics. These trends include industry consolidation, disruptive technologies, Moore's law, electronic atlases and on-line databases. Each of these trends is explained and documented, relative to their influence on craniofacial imaging. RESULTS: Craniofacial imaging is influenced by major trends that affect all medical imaging and related informatics applications. The introduction of cone beam craniofacial computed tomography scanners is an example of a disruptive technology entering the field. An important opportunity lies in the integration of biologic knowledge repositories with craniofacial images. CONCLUSION: The progress of craniofacial imaging will continue subject to limitations imposed by the underlying technologies, especially imaging informatics. Disruptive technologies will play a major role in the evolution of this field.

Databases as Topic↗
PubMed2005

Small animal positron emission tomography in food sciences.

Positron emission tomography (PET) is a 3-dimensional imaging technique that has undergone tremendous developments during the last decade. Non-invasive tracing of molecular pathways in vivo is the key capability of PET. It has become an important tool in the diagnosis of human diseases as well as in biomedical and pharmaceutical research. In contrast to other imaging modalities, radiotracer concentrations can be determined quantitatively. By application of appropriate tracer kinetic models, the rate constants of numerous different biological processes can be determined. Rapid progress in PET radiochemistry has significantly increased the number of biologically important molecules labelled with PET nuclides to target a broader range of physiologic, metabolic, and molecular pathways. Progress in PET physics and technology strongly contributed to better scanners and image processing. In this context, dedicated high resolution scanners for dynamic PET studies in small laboratory animals are now available. These developments represent the driving force for the expansion of PET methodology into new areas of life sciences including food sciences. Small animal PET has a high potential to depict physiologic processes like absorption, distribution, metabolism, elimination and interactions of biologically significant substances, including nutrients, 'nutriceuticals', functional food ingredients, and foodborne toxicants. Based on present data, potential applications of small animal PET in food sciences are discussed.

Animal Nutritional Physiological Phenomena↗
PubMed1985

The usefulness, in pharmacological classification, of complementary pattern-recognition techniques and structure modelling as afforded by the iterative collation of multiple-trial data in data banks.

In this emerging information age no significant limits can be envisaged to the immense resources of knowledge that pharmacological sciences can draw upon by systematically applying multivariate pattern-recognition techniques to those data banks which can be organized internationally with better standardization of descriptors, i.e. by parametrizing observations and evaluating monitoring in experimental, biological assays, clinical trials and postmarketing surveillance. Even conventionally or habitually adopted references and communalities such as traditional drug profiles and receptor models may be iteratively re-checked and suitably adapted so as to take account of more adequate, up-to-date analytical techniques, fresh biological ideas and new advances in terms of physiological refinements. An attempt may also be made to modify the chemicophysical relationships and patterns currently traced on the basis of what are held to be quantitative structure-activity oversimplifications. The present paper focuses upon specifying a number of standardization criteria in conventional assays and upon submitting multiple biological features to monitoring; in addition, it gives some picture of the new trends the approach can offer and draws attention to the more relevant, innovative literature references.

Animals↗