Biomedical subjects

Da-Wei Wang

Publications and source records attributed to Da-Wei Wang.

8 recordsLinked to original sources

PubMed2006

Seasonal changes in chronic social interactions and physiological states in female rat-like hamsters (Tscheskia triton).

We examined the behavioral characteristics and physiological states related to solitary lifestyle and dominant-subordinate relationships in female rat-like hamsters (Tscheskia triton), formerly known as Cricetulus triton. Wild adult hamsters were captured and caged singly in the laboratory during the non-breeding and breeding seasons. The experimental hamsters were subjected to 5 min staged dyadic encounters every day for 28 consecutive days by pairing two unfamiliar and weight matched females in a neutral arena. Aggressive behavior, defense and flank marking were quantified everyday within the first week and once each week during the last 3 weeks. Animals were then autopsied and their physiological and reproductive state assessed. Our results suggested that dominant-subordinate relationships could be established especially in non-breeding conditions, where the dominant displayed higher aggression and flank marking, and lower defense than its opponent. The breeding females followed this pattern except there was no difference in aggressive behavior, between the partners. The repeated encounters did not appear to reduce aggression or lead to amiable behavior or bonding. At the end of the experiment breeding females exhibited higher levels of serum estradiol, progesterone and corticosterone than non-breeding females. Both dominant and subordinate females in non-breeding condition had atrophied ovaries and uteri, whereas both dominant and subordinate females in breeding condition had hypertrophied ovaries and uteri. Non-breeding females possessed heavier and thicker flank glands than breeding females did. Dominant females displayed longer or thicker flank glands than subordinate did. Thus, our data suggest that the behavioral traits observed in our experiment support the solitary lifestyle of adult female rat-like hamsters and physiological state show some differences between social ranks or in both seasons.

Aggression↗

PubMed2006

Stepped changes of monovalent ligand-binding force during ligand-induced clustering of integrin alphaIIB beta3.

Recent evidence demonstrated that conformational changes of the integrin during receptor activation affected its binding to extracellular matrix; however, experimental assessment of ligand-receptor binding following the initial molecular interaction has rarely been carried out at a single-molecule resolution. In the present study, laser tweezers were used to measure the binding force exerted by a live Chinese hamster ovary cell that expressed integrin alphaIIb beta3 (CHO alphaIIb beta3), to the bead carrier coated with the snake venom rhodostomin that served as an activated ligand for integrin alphaIIb beta3. A progressive increase of total binding force over time was noticed when the bead interacted with the CHO alphaIIb beta3 cell; such an increase was due mainly to the recruitment of more integrin molecules to the bead-cell interface. When the binding strength exerted by a single ligand-receptor pair was derived from the "polyvalent" measurements, surprisingly, a stepped decrease of the "monovalent binding force" was noted (from 4.15 to 2.54 piconewtons (pN)); such decrease appeared to occur during the ligand-induced integrin clustering process. On the other hand, the mutant rhodostomin defective in clustering integrins exhibited only one (1.81 pN) unit binding strength.

Animals↗

PubMed2006

Effect of pore packing defects in 2-d ordered mesoporous carbons on ionic transport.

Ordered mesoporous materials show great importance in energy, environmental, and chemical engineering. The diffusion of guest species in mesoporous networks plays an important role in these applications, especially for energy storage, such as supercapacitors based on ordered mesoporous carbons (OMCs). The ion diffusion behavior in two different 2-D hexagonal OMCs was investigated by using cyclic voltametry and electrochemical impedance spectroscopy. In addition, transmission electron microscopy, small-angle X-ray diffraction, and nitrogen cryosorption methods were used to study the pore structure variations of these two OMCs. It was found that, for the OMC with defective pore channels (termed as pore packing defects), the gravimetric capacitance was greatly decayed when the voltage scan rate was increased. The experimental results suggest that, for the ion diffusion in 2-D hexagonal OMCs with similar mesopore size distribution, the pore packing defect is a dominant dynamic factor.

Journal Article↗

PubMed2006

Developing and evaluating a wireless speech-and-touch-based interface for intelligent comprehensive triage support systems.

Continuous speech recognition (CSR) technology appears promising in mobile nursing but is not yet well studied. We developed and evaluated bimodal CSR and touchscreen triage support systems in the Emergency department (ED) of a medical center with 2700 beds in 2004-5. Evaluation results show that the average accuracy rates of systems ranged from 94 to 98%. Results suggest that the ED nurses were significantly more willing to use CSR combined with touchscreen systems than the others, such as PDA and CSR alone. A more flexible interface, not efficiency, might be the main reason for this finding.

Attitude to Computers↗

PubMed2005

Development of a deterministic XML schema by resolving structure ambiguity of HL7 messages.

Health level 7 (HL7) is a standard for medical information exchange. It defines data transfers for the application systems in the healthcare environment. Alternatively, the extensible markup language (XML) is a standard for data exchange using the Internet. If exchange messages follow the content and the sequence defined by HL7 and are expressed in the XML format, the system may benefit from the advantages of both standards. In creating the XML schema, we found ambiguities in HL7 message structures that cause the XML schema to be non-deterministic. These ambiguous expressions are summarized within 12 structures and can be replaced with equivalent or similar unambiguous structures. The finite state automata are used to verify expression equivalence. Applying this schema, an XML document may eliminate redundant segment group definitions and make the structure simple and easy to reproduce. In this paper, we discuss the methods and our experience in resolving ambiguous problems in HL7 messages to generate a deterministic XML schema.

Health Status↗

PubMed2004

Medical privacy protection based on granular computing.

Based on granular computing methodology, we propose two criteria to quantitatively measure privacy invasion. The total cost criterion measures the effort needed for a data recipient to find private information. The average benefit criterion measures the benefit a data recipient obtains when he received the released data. These two criteria remedy the inadequacy of the deterministic privacy formulation proposed in Proceedings of Asia Pacific Medical Informatics Conference, 2000; Int J Med Inform 2003;71:17-23. Granular computing methodology provides a unified framework for these quantitative measurements and previous bin size and logical approaches. These two new criteria are implemented in a prototype system Cellsecu 2.0. Preliminary system performance evaluation is conducted and reviewed.

Computing Methodologies↗

PubMed2003

Preserving confidentiality when sharing medical database with the Cellsecu system.

We propose a computer system called Cellsecu that maintains the anonymity and the confidentiality of each cell containing sensitive information in medical database. Cellsecu attains this by automatically removing, generalizing, and expanding information. It is designed to enhance data privacy protection so a data warehouse can automatically handle queries. In most cases, health organizations collect medical data with explicit identifiers, such as name, address and phone number. Simply removing all explicit identifiers prior to release of the data is not enough to preserve the data confidentiality. Remaining data can be used to re-identify individuals by linking or matching the data to other database, or by looking at unique characteristics found in the database. A formal model based on Modal logic is the theoretical foundation of Cellsecu. As well, a new confidentiality criteria called "non-uniqueness" is defined and implemented. We believe modeling this problem formally can clarify the issue as well as clearly identify the boundary of current technology. Base on our preliminary performance evaluation, the confidentiality check module and the confidentiality enhancing module only slightly degrade system performance.

Computer Security↗

PubMed2002

[FTIR investigation on crystal chemistry of CO(2-)3-substituted apatite solid solutions prepared through different methods].

The CO(2-)3-substituted apatite solid solutions were prepared through different methods. The FTIR and XRD measurements were applied to investigate its crystal chemistry properties. The results indicated that the CO(2-)3-substituted sites in the carbonate hydroxyapatite(CHAP) prepared through homogeneous precipitation method are type-B in which [CO3.OH] tetrahedral-coordinations are substituted for [PO4] tetrahedral-coordinations; the ones in the CHAP prepared through solid phase ions exchange method are type-A in which [CO3] triangle-coordinations are substituted for [OH] in column sites; the ones in the carbonate fluorapatite(CFAP) prepared through solid phase reaction method are type-B in which [CO3.F] tetrahedral-coordinations are substituted for [PO4] tetrahedral-coordinations; the ones in the CHAP prepared through sol-gel method are AB mixed-type. The vibrational band psi 3 is splitted into psi 3-1, psi 3-4 and psi 3F. The psi 3F is combined by psi 3-2 (type-A) and psi 3-3 (type-B) in Gaussian function fitting. When Wco(2-)3 < 3.34%, substitution value of type-A increases with the increasing of CO(2-)3 contents. When Wco(2-)3 = 3.34%, substitution value of type-A has maximum. When 3.34% < Wco(2-)3 < 7.52%, substitution value of type-B increases with the increasing of CO(2-)3 contents. When Wco(2-)3 = 7.52%, substitution value of type-B has maximum.

Apatites↗