Biomedical subjects

D-Y Yang

Publications and source records attributed to D-Y Yang.

5 recordsLinked to original sources

PubMed2007

The psychological effect of severe acute respiratory syndrome on emergency department staff.

BACKGROUND: The severe acute respiratory syndrome (SARS) outbreak in 2003 affected 29 countries. The SARS outbreak was unique in its rapid transmission and it resulted in heavy stress in first-line healthcare workers, particularly in the emergency department. AIM: : To determine the influence of SARS on the psychological status, including post-traumatic stress disorder (PTSD) symptoms, of the staff in the emergency department. METHODS: To investigate whether different working conditions in the hospital led to different psychological effects on healthcare workers, the psychological effect on emergency department staff in the high-risk ward was compared with that on psychiatric ward staff in the medium-risk ward. Davidson Trauma Scale-Chinese version (DTS-C) and Chinese Health Questionnaire-12 (CHQ-12) items were designed to check the psychological status of the staff in the month after the end of the SARS outbreak. RESULTS: 86 of 92 (93.5%) medical staff considered the SARS outbreak to be a traumatic experience. The DTS-C scores of staff in the emergency department and in the psychiatric ward were significantly different (p = 0.04). No significant difference in CHQ score was observed between the two groups. Emergency department staff had more severe PTSD symptoms than staff in the psychiatric ward. CONCLUSION: SARS was a traumatic experience for healthcare providers in Taiwan. Most staff in the emergency department and in the psychiatric ward had PTSD. Emergency department staff had more severe PTSD symptoms than staff in the psychiatric ward.

Adult↗

PubMed2005

Two approaches toward a high-efficiency flashing ratchet.

For a flashing ratchet with periodic potentials fluctuating via random shifts of one-half period, a high efficiency is shown to result from two mechanisms. The previously reported one [Yu. A. Makhnovskii, Phys. Rev. E 69, 021102 (2004); V. M. Rozenbaum, JETP Lett. 79, 388 (2004)] is realized in the near-equilibrium region and implies, first, the presence of a high barrier V0 blocking the reverse movement of a Brownian particle and, second, identical, though energy-shifted, portions of the asymmetric flat potential profile on both half periods. We report another mechanism acting far from equilibrium, typical of strongly asymmetric potentials which are shaped identically on both half periods with a large energetic shift DeltaV . The two mechanisms exhibit radically different limiting behavior of the maximum possible efficiency: eta(m) approximately 1-exp (-beta V0 /2) for the former and eta(m) approximately 1-ln (2betaDeltaV) /betaDeltaV for the latter ( beta being the reciprocal temperature in energy units). The flux and the efficiency for a Brownian motor with a piecewise-linear potential are calculated using the transfer matrix method; an exact analytical solution can thus be obtained for an extremely asymmetric sawtooth potential, the simplest example of the second high-efficiency mechanism. As demonstrated, the mechanisms considered are also characteristic of a two-well periodic potential treated in terms of the kinetic approach.

Algorithms↗

PubMed2004

Flashing ratchet model with high efficiency.

As a simple model of the Brownian motor, we consider hopping motion of a particle in a periodic asymmetric double-well potential which randomly switches between two states. The potential profiles of the states are identical but shifted by half a period. The current and the efficiency are explicitly calculated as functions of the parameters of the model, including also a load force. Such a flashing ratchet is shown to be particularly efficient, with the efficiency tending to unity when the highest peak of the potential is high enough to suppress the backward motion.

Journal Article↗

PubMed2003

Comparison of cadaveric pericardial, dermal, vein, and synthetic grafts for tunica albuginea substitution using a rat model.

OBJECTIVE: To evaluate in an animal model the intermediate and long-term efficacy of cadaveric pericardium, dermis, vein and Gore-Tex per thousand as grafting materials for tunica albuginea substitution after plaque excision for Peyronie's disease. MATERIALS AND METHODS: The study comprised 100 male Sprague-Dawley rats (300-325 g) divided into five equal groups: group 1, sham-operated controls; and groups 2-5 which underwent wedge excision of the tunica albuginea and replacement with either cadaveric pericardium, dermis, vein or Gore-Tex grafts. Ten rats in each group had the cavernosal nerve stimulated electrically to assess erectile function at 4 months, and the remaining 10 rats at 6 months. After death the sampled tissues were fixed in 10% formalin, paraffin-embedded, and stained with Masson's trichrome and Verhoff's van Giesen for collagen and elastic fibres. RESULTS: Erectile function, assessed by cavernosal nerve stimulation, did not differ significantly in any of the groups (P > 0.05). The histological assessment of penile cross-sections showed minimal fibrosis surrounding the patch in the dermal and vein grafts, and moderate to severe fibrosis in the Gore-Tex graft at 4 and 6 months. In the pericardial graft there was a moderate degree of fibrosis at 4 months with only minimal fibrosis at 6 months. CONCLUSIONS: These results show that cadaveric pericardium allows complete penile expansion and is strong enough to withstand normal intracorporal pressures. There was minimal fibrosis in the pericardial, dermal and vein grafts, and moderate fibrosis in the Gore-Tex graft at 6 months. The pericardial graft is a satisfactory grafting material when used for tunica albuginea substitution, including the surgical management of Peyronie's disease.

Animals↗

PubMed2002

Localization of peripheral dopamine D1 and D2 receptors in rat corpus cavernosum.

OBJECTIVE: To detect and locate anatomically peripheral dopamine D1 and D2 receptors in rat cavernosa, as dopamine is important in sexual drive and penile erection through receptors located in the central nervous system. MATERIALS AND METHODS: Corpora cavernosa were obtained from Sprague-Dawley rats; total RNA and membrane proteins were extracted and cryostat sections prepared. The rat brain hypothalamus was used as a control for dopamine D1 and D2 receptors. The presence and expression of peripheral dopamine D1 and D2 receptor mRNAs in rat corpus cavernosa was assessed using reverse transcription and polymerase chain reaction (RT-PCR), and Northern blot hybridization using (32)P-UTP-labelled RNA probes. Concurrently, corresponding proteins from D1 and D2 receptors were assayed and detected by a Western blotting technique. The anatomical location of dopamine D1 and D2 receptor mRNAs in rat penile tissues was identified by in situ hybridization using (35)S-UTP-labelled RNA probes in cryostat sections. Immunohistochemical staining was used to locate peripheral dopamine D1 and D2 receptor proteins in rat corpora cavernosa. RESULTS: Dopamine D1 and D2 receptor gene expression was detected in rat corpora cavernosa. In situ hybridization signals for dopamine D1 and D2 receptor mRNAs were localized to corpus cavernosal tissues and dorsal vessels in the rat penis. Western blot analyses showed peripheral dopamine D1 and D2 receptor proteins in rat corpora cavernosa. Immunohistochemically, peripheral dopamine D1 and D2 receptor proteins were detected in dorsal nerves, dorsal vessels and corpus cavernosal smooth muscle of the rat penile tissues. CONCLUSIONS: Peripheral dopamine D1 and D2 receptors are present in the corpora cavernosa of rats. The functional significance of these receptors and signal transduction pathways in modulating the vascular tone of the penis warrants further investigation.

Animals↗