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Biomedical subjects

S T Tang

Publications and source records attributed to S T Tang.

9 recordsLinked to original sources
PubMed2005

Industrial wideband noise reduction for hearing aids using a headset with adaptive-feedback active noise cancellation.

High-intensity noises are a health hazard for industrial workers, and hearing protection is necessary to prevent hearing loss. Passive methods, such as ear muffs, are ineffective against low-frequency noise. Moreover, many hearing-impaired workers must wear hearing aids to enable communication at their workplace, and such aids can amplify ambient noise. To overcome this problem, the present study developed a headset equipped with a digital signal processing system to implement adaptive-feedback active noise cancellation (AFANC) to reduce low-frequency noise. The proposed AFANC headset was effective against wideband industrial noise, with a maximum noise spectrum power reduction of 30 dB. Furthermore, when used with a hearing aid, it improved the speech signal-to-noise ratio by up to 14 dB. These results suggest that a headset with AFANC would be useful for hearing protection in workplaces with high levels of low-frequency industrial noise, especially for hearing-impaired workers.

Ear Protective Devices↗
PubMed2001

Beneficial effect of HCL-31D in murine models of endotoxaemia.

We evaluated the effect of HCL-31D, a novel cAMP-specific phosphodiesterase inhibitor, on the induction of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-treated rat aortic smooth muscle cells (RASMC) and on survival in a murine model of severe endotoxaemia. Treatment of cultured RASMC with LPS and IFN-gamma resulted in an increase of nitrite, tumour necrosis factor (TNF-alpha) production and induction of iNOS mRNA. However, incubation with HCL-31D (1 approximately 50 microM) for 24 h caused significant attenuation of nitrite and TNF-alpha formation as well as iNOS mRNA induction in a dose-dependent manner but no effect on iNOS activity in RASMC. In addition, administration of HCL-31D (5 mg/kg, i.p.) resulted in that the increase of both plasma nitrate and TNF-alpha levels induced by LPS in vivo was significantly reduced in LPS-treated rats. Treatment of conscious mice with a high dose of LPS (60 mg/kg, i.p.) to ICR mice resulted in a 24-h survival rate of only 10%. However, administration of HCL-31D (5 mg/kg, i.p. at 0 h and 6 h after LPS) improved the 24-h survival to 50%, indicating that HCL-31D has a beneficial effect in murine model endotoxaemia. These effects may be mainly due to inhibition of TNF-alpha formation and of the induction of iNOS. We proposed that the elevation of cAMP levels by HCL-31D may be involved in the prevention of TNF-alpha formation and iNOS induction.

Animals↗
PubMed2001

Determinants of place of death for terminal cancer patients.

Approximately two-third of cancer patients, when asked about the preferred place of death, wish to die in their own homes. However, the majority of deaths from cancers in most western countries occur in a hospital. When a person dies from other than sudden or traumatic causes, the death appears to be a function of a complex interplay of personal and cultural values and physical and medical factors, as well as various health care systems forces. This article reviews the determinants of place of death for terminal cancer patients from published studies in hopes of shedding light on the difficulties of dying patients to realize their preferences for place of death. These insights may contribute to modification of hospice care systems so health professionals will be more responsive to the needs of their dying patients to retain control and die with dignity and help health professionals achieve the proposed outcome of hospice care.

Attitude to Death↗
PubMed2001

3 x 3 matrix for unitary optical systems.

We introduce a 3 x 3 matrix for the study of unitary optical systems. This 3 x 3 matrix is a submatrix of the 4 x 4 Mueller matrix. The elements of this 3 x 3 matrix are real, and thus complex-number calculations can be avoided. The 3 x 3 matrix is useful for illustrating the polarization state of an optical system. One can also use it to derive the conditions for linear and circular polarization output for a general optical system. New characterization methods for unitary optical systems are introduced. It is shown that the trajectory of the Stokes vector on a Poincaré sphere is either a circle or an ellipse as the optical system or input polarizer is rotated. One can use this characteristic circle or ellipse to measure the equivalent optical retardation and rotation of any lossless optical system.

Journal Article↗
PubMed2001

[High performance liquid chromatographic determination of domoic acid in shellfish samples].

Domoic acid in shellfish samples was determined by HPLC with DAD/UV detector at 242 nm. Samples were extracted with methanol-water followed by clean-up of the extracts with strong anion exchange solid phase extraction cartridge(3 mL LC-SAX). Zorbax SB-C18 column, 150 mm x 4.6 mm i.d., and mobile phase of acetonitrile-0.1% aqueous trifluoroacetic acid(13:87, V/V) were used for the assay. The quantitative analysis was performed with external standard. The calibration curve of domoic acid was linear in the range of 1.0 m/L-25.0 mg/L and the detection limit was ca. 0.2 microgram/g.

Animals↗
PubMed2000

Meanings of dying at home for Chinese patients in Taiwan with terminal cancer: a literature review.

To maintain dignity, patients with terminal cancer must be able to do things in their own way, to make their own decisions, and to preside over their own dying. Among the tasks considered essential for patients with terminal cancer is deciding where they prefer to die. The actual place of death has been recognized in hospice care as indicating quality of care. Approximately two-thirds of patients with cancer, when asked about the preferred place of death, say they wish to die in their own homes. Patients with terminal cancer dying at home may find physical and emotional comfort there. Home is a place where people may feel safety and a sense of belonging. In dying at home, patients with terminal cancer also may have a greater chance to control their environment, more autonomy and privacy, and a sense of normality. In this article, special cultural meaning of dying at home for the Chinese patient and the family is reviewed. It is essential for health care professionals to understand Chinese cultural beliefs and values related to dying at home in order to provide culturally sensitive care for Chinese dying patients and their families and to enhance their sense of control over the unknown process of dying.

Attitude to Health↗