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S H Lin

Publications and source records attributed to S H Lin.

At least 37 records · Page 2Linked to original sources
PubMed2005

Apoptotic markers on lymphocytes and monocytes are unchanged during single hemodialysis sessions using either regenerated cellulose or polysulfone membranes.

BACKGROUND: There is an increased rate of apoptosis of peripheral blood mononuclear cells (PBMCs) in patients undergoing hemodialysis (HD), but little is known about how different dialysis membranes may contribute to the process. We, therefore, studied the influence of two different dialysis membranes on apoptotic markers during HD. METHODS: 8 healthy controls and 8 patients on regular HD 3 times per week were enrolled in this cross-controlled study. Patients received HD using polysulfone and then regenerated cellulose dialysis membranes for one week each, sequentially. Serum was collected for C-reactive protein (CRP) detection; flow cytometry with dual antibody staining was used to measure the apoptotic markers Fas (CD95), FasL (CD 178) and TNF-R2 (CD120b) in T cells (CD3+), B cells (CD19+), and monocytes (CD14+) at 0, 15, 120 and 240 min after starting HD. We also measured total leukocyte numbers and differential white cell counts. RESULTS: Hemodialysis patients revealed lymphocytopenia, monocytopenia, higher CRP levels and higher Fas and TNF-R2 expression on lymphocytes and monocytes at baseline when compared with normal controls. Leukocyte numbers, including neutrophils, lymphocytes and monocytes, dropped significantly after 15 min of dialysis. There were no significant differences in Fas levels during hemodialysis on T and B lymphocytes or on monocytes. T lymphocyte FasL (CD 178) levels remained unchanged throughout the process. There was a significantly lower overall level of CD120b at 15 min of HD, whereas this marker was higher on monocytes after dialysis. There were no significant differences in the levels of apoptotic markers between the two membranes. CONCLUSION: Our results suggest that uremia itself contributes to PBMC apoptosis. The two different dialysis membranes used in this study did not influence apoptotic markers on PBMCs significantly, but increased TNF-R2 expression on monocytes during a single dialysis session.

Adult↗
PubMed2004

Photodissociation of benzene under collision-free conditions: an ab initio/Rice-Ramsperger-Kassel-Marcus study.

The ab initio/Rice-Ramsperger-Kassel-Marcus (RRKM) approach has been applied to investigate the photodissociation mechanism of benzene at various wavelengths upon absorption of one or two UV photons followed by internal conversion into the ground electronic state. Reaction pathways leading to various decomposition products have been mapped out at the G2M level and then the RRKM and microcanonical variational transition state theories have been applied to compute rate constants for individual reaction steps. Relative product yields (branching ratios) for C(6)H(5)+H, C(6)H(4)+H(2), C(4)H(4)+C(2)H(2), C(4)H(2)+C(2)H(4), C(3)H(3)+C(3)H(3), C(5)H(3)+CH(3), and C(4)H(3)+C(2)H(3) have been calculated subsequently using both numerical integration of kinetic master equations and the steady-state approach. The results show that upon absorption of a 248 nm photon dissociation is too slow to be observable in molecular beam experiments. In photodissociation at 193 nm, the dominant dissociation channel is H atom elimination (99.6%) and the minor reaction channel is H(2) elimination, with the branching ratio of only 0.4%. The calculated lifetime of benzene at 193 nm is about 11 micros, in excellent agreement with the experimental value of 10 micros. At 157 nm, the H loss remains the dominant channel but its branching ratio decreases to 97.5%, while that for H(2) elimination increases to 2.1%. The other channels leading to C(3)H(3)+C(3)H(3), C(5)H(3)+CH(3), C(4)H(4)+C(2)H(2), and C(4)H(3)+C(2)H(3) play insignificant role but might be observed. For photodissociation upon absorption of two UV photons occurring through the neutral "hot" benzene mechanism excluding dissociative ionization, we predict that the C(6)H(5)+H channel should be less dominant, while the contribution of C(6)H(4)+H(2) and the C(3)H(3)+C(3)H(3), CH(3)+C(5)H(3), and C(4)H(3)+C(2)H(3) radical channels should significantly increase.

Journal Article↗
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↗
PubMed2004

Theoretical differential Raman scattering cross-sections of totally-symmetric vibrational modes of free pyridine and pyridine-metal cluster complexes.

The differential Raman scattering cross-sections of totally-symmetric vibrational modes for pyridine and pyridine-metal clusters have been calculated by using ab initio and density functional methods. The results are compared with experimental data and a good agreement is obtained. In particular, we can theoretically reproduce the significant changes in the relative Raman intensities of the nu(12) mode in pyridine-metal cluster complexes. We focus on two mechanisms for these Raman intensities changes: (1) the chemical interaction between the pyridine and the metal clusters; and (2) the charge transfer mechanism. For the pyridine-silver cluster complexes, we find that due to the weak bonding, the chemical interaction does not influence the relative intensities of the Raman peaks of the nu(1) and nu(12) modes. However, in the case where the copper or the gold clusters are attached to pyridine, the intensity of the band of the nu(12) mode is weakened significantly. We also find that the charge transfer mechanism increases the asymmetry of the bands of the nu(1) and nu(12) modes on all three metals.

Carbon↗
PubMed2003

Adsorption and catalytic oxidation of phenol in a new ozone reactor.

Phenolic wastewater treatment in a new ozone reactor was investigated. The reactor was designed in such a fashion that gas induction was created in the reactor headspace by the high-speed action of an impeller turbine inside a draft tube to maximize the ozone utilization. Another important feature of the present reactor design was incorporation of granular activated carbon bed in a circular compartment between the reactor wall and the shaft tube. The fixed granular activated carbon bed was observed to significantly enhance the phenol decomposition and the chemical oxygen demand removal when compared to gas-induced ozonation alone, providing evidence of the synergistic effects of adsorption, catalytic reaction and ozonation. In addition to the enhanced phenol decomposition and chemical oxygen demand, ozonation was found to provide in-situ regeneration of granular activated carbon which was considered crucial in the present reaction system. Kinetic investigations were also made using a proposed complex kinetic model in an attempt to elucidate the possible decomposition reaction mechanisms of the present gas-induced ozonation system.

Adsorption↗
PubMed2003

Steroid-induced tumor lysis syndrome in a patient with preleukemia.

Tumor lysis syndrome (TLS) is a well recognized complication of chemotherapy and radiotherapy for leukemia, lymphoma as well as rapidly growing malignancies. Less described is the occurrence of TLS following steroid therapy alone. Herein, we report on a 32-year-old male with myelodysplastic syndrome, characterized by refractory anemia with excess blasts in transformation, who developed acute oliguric renal failure 12 hours after methylprednisolone 1.0 g for presumed autoimmune thrombocytopenia. Laboratory investigations revealed typical findings of TLS, including hyperkalemia, marked hyperuricemia, hyperphosphotemia, hypocalcemia and urine uric acid to creatinine ratio 1.8 (> 1.0). Long hemodialysis (8 hours) was initiated for 3 consecutive sessions. Renal function recovered 1 week later. This case high-lights that single-dose steroid administration in a patient with hematological malignancy may cause the potential life-threatening complications of TLS. Prophylactic management prior to the use of steroid therapy for a variety of purposes is absolutely required in high-risk patients.

Acute Kidney Injury↗
PubMed2002

Photoisomerization and photodissociation of toluene in molecular beam.

The photodissociation of isotope-labeled toluene C(6)H(5)CD(3) and C(6)H(5)(13)CH(3) molecules at 6.4 eV under collision-free conditions was studied in separate experiments by multimass ion imaging techniques. In addition to the major dissociation channels, C(6)H(5)CD(3) --> C(6)H(5)CD(2) + D and C(6)H(5)CD(3) --> C(6)H(5) + CD(3), the respective photofragments CD(2)H, CDH(2), and CH(3) and their heavy fragment partners C(6)H(4)D, C(6)H(3)D(2), and C(6)H(2)D(3) were observed from C(6)H(5)CD(3) dissociation. Photofragments (13)CH(3) and CH(3), and their heavy fragment partners C(6)H(5) and (13)CC(5)H(5), were also observed from C(6)H(5)(13)CH(3) dissociation. Our results show that 25% of the excited toluene isomerizes to a seven-membered ring (cycloheptatriene) and then rearomatizes prior to dissociation. The isomerization pathway competes with direct C-C bond and C-H bond dissociation. The significance of this isomerization is that the carbon atoms and hydrogen atoms belonging to the alkyl group are involved in an exchange with those atoms in the aromatic ring during isomerization. The dissociation rate of toluene at 193 nm is measured to be (1.17 +/- 0.1) x 10(6) s(-)(1).

Journal Article↗
PubMed2002

Adsorption of phenol and m-chlorophenol on organobentonites and repeated thermal regeneration.

Experimental investigations were conducted on the adsorption characteristics of phenol and m-chlorophenol by organobentonites. The organobentonites were prepared by modifying natural bentonite with various quaternary ammonium salts including tetramethylammonium bromide, hexadecyltrimethylammonium bromide, benzyl-triethylammonium bromide, tetraethylammonium bromide and cetylpyridinium bromide. The adsorption characteristics of phenol and chlorophenol by these organobentonites were examined in detail. The empirical Freundlich isotherm was found to describe well the equilibrium adsorption data. Thermal regeneration of spent organobentonites was also investigated and operating conditions of 200 degrees C and 2 h heating were found to yield very good results.

Adsorption↗
PubMed2002

Effect of pretreatment with ketorolac on propofol injection pain.

BACKGROUND: : Pain on injection is still a major problem with propofol. We performed this study to compare different doses of intravenous (i.v.) ketorolac with and without venous occlusion and its effect on the incidence and the severity of the pain after propofol injection. METHODS: We conducted a prospective, randomized and double-blind study of 180 patients (20-60 years of age.) scheduled to undergo elective surgery. Six groups of patients were generated: group A received normal saline (NS) 2 ml i.v.; groups B, C, D received ketorolac 10 mg in 2 ml NS with venous occlusion (VO) and a subsequent propofol injection at either 30, 60 or 120 s; groups E and F received ketorolac 15 mg and 30 mg in 2 ml NS and propofol was injected after 60 s. The pain perception was assessed during injection of propofol in all patients. RESULT: : The incidence of propofol-associated injection pain was for A: 46.7%; B: 43.4%; C: 23.3%; D:16.7%; E: 20%, and F: 10%. The incidence of pain following propofol injection was reduced by i.v. ketorolac 10 mg with venous occlusion for 120 s. Furthermore, i.v. ketorolac 15 mg and 30 mg but not 10 mg following propofol injection after 60 s without venous occlusion revealed significant pain reduction when compared to saline group. There was no difference in venous sequelae at 7 days postoperatively between the groups. CONCLUSION: Our results suggested that pretreatment with i.v. 15 and 30 mg ketorolac reduces pain following propofol injection. Moreover, pretreatment with i.v. ketorolac 10 mg with venous occlusion for 120 s achieves the same pain relief effect.

Adult↗
PubMed2002

Optimization of multistage phenol adsorption by organobentonites: theoretical developments and experimental verification.

Material balance equations were developed for representing phenol adsorption by organobentonites in a countercurrent multistage adsorption process. The developed equations were employed to analyze the adsorption performance of the multistage process. Results of the theoretical analyses using empirical Freundlich adsorption isotherm had shown that the multistage process is more efficient than the single-stage process in terms of phenol removal per unit amount of organobentonite. It was also shown that equal division of the total amount of organobentonite among all adsorption stages yields the best overall phenol removal efficiency for the multistage process in comparison with other organobentonite allocations. The Freundlich adsorption isotherm was confirmed by experimental tests to describe well the phenol adsorption by organobentonites. Results of theoretical performance analyses of the multistage adsorption process were experimentally verified using two- and three-stage test examples.

Adsorption↗
PubMed2002

Use of reconstruction nails to manage ipsilateral displaced femoral neck-shaft fractures: assessment of a new approach.

PURPOSE: Owing to unpredictable femoral neck reduction, reconstruction nails are not suitable for fixation of group 3 ipsilateral femoral neck-shaft fractures. We developed a new one-step fixation technique to overcome this problem. This study aims to assess this new technique at the Orthopaedic Department, Chi-Mei Foundation Medical Center, Tainan. METHODS: Of 31 consecutive patients with femoral fractures treated by reconstruction nails, five patients had group 3 ipsilateral femoral neck-shaft fractures, 4 of whom were treated by a new surgical technique. Two 5.0-mm drills were firstly inserted to tether the trochanter fragment, and distal locking screws were secondly applied to immobilise the shaft fracture. The neck-shaft angle was then restored in a closed fashion and proximal cephalomedullary screws were attached. Patients were followed up by post-operative radiography. RESULTS: All 5 cases of group 3 ipsilateral femoral neck-shaft fracture obtained radiographic union without significant surgical sequelae. Three of the patients had implants removed. No patients presented with osteonecrosis at the 3-year follow-up. CONCLUSION: The new approach to manage ipsilateral femoral neck-shaft fractures by using reconstruction nails obtains relatively good clinical results.

Adult↗
PubMed2002

Severe hyponatremia as the presenting feature of clinically non-functional pituitary adenoma with hypopituitarism.

Hyponatremia can result from a wide range of causes. While hyponatremia is known to occur in patients with hypopituitarism, severe hyponatremia occurring as the presenting feature of hypopituitarism is very rare. We present two cases in which severe hyponatremia developed with weakness, light-headedness and seizure. The hyponatremia in these 2 cases mimicked the laboratory diagnostic criteria of a syndrome of inappropriate secretion of antidiuretic hormone (SIADH). However, the hormone studies displayed hypopituitarism. Hyponatremia was completely corrected after administering a supplement of prednisolone and L-thyroxine. Computerized tomography of the brain revealed an adenoma of the pituitary gland. These two cases illustrate that severe hyponatremia may be the presenting feature of clinically non-functional pituitary adenoma with hypopituitarism, which should be kept in mind in the differential diagnosis of hyponatremia mimicking SIADH.

Adenoma↗
PubMed2002

Arteriovenous fistula using transposed basilic vein in chronic hypotensive hemodialysis patients.

AIM: Chronic hypotension is not uncommon in uremic patients on regular hemodialysis. This subset of patients often requires multiple operations to maintain their vascular access due to frequent thrombosis and occlusion of the arteriovenous fistula. Our aims was to assess whether surgical intervention with the brachial artery-transposed basilic vein fistula is effective in chronic hypotensive hemodialysis patients. MATERIALS AND METHODS: Fifty-four hemodialysis patients with chronic hypotension were enrolled in this study. Most ofthem were referred from local hospitals. They were 23 men and 31 women. The brachial artery-transposed basilic vein arteriovenous fistula was performed in a period of 46 months at the teaching hospital. Primary patency was defined as the length of time from the fistula creation until the development of thrombosis or a complication that required operative revision ofthe fistula. Secondary patency was defined by whether the fistula could be salvaged by revision such that blood flow was maintained. RESULTS: There was no technical failure and none of these patients died due to the surgical operation. The primary patency rate was 89.80% at 1 year, 73.08% at 2 years, and 64.710% at 3 years. The secondary patency rate was 95.92% at 1 year, 84.62% at 2 years, and 76.47% at 3 years. CONCLUSIONS: Brachial artery-transposed basilic vein arteriovenous fistula may present good primary alternative vascular access in chronic hypotensive hemodialysis patients.

Adult↗
PubMed2001

NudC associates with Lis1 and the dynein motor at the leading pole of neurons.

NUDC is a highly conserved protein important for nuclear migration and viability in Aspergillus nidulans. Mammalian NudC interacts with Lis1, a neuronal migration protein important during neocorticogenesis, suggesting a conserved mechanism of nuclear movement in A. nidulans and neuronal migration in the developing mammalian brain (S. M. Morris et al., 1998). To further investigate this possibility, we show for the first time that NudC, Lis1, and cytoplasmic dynein intermediate chain (CDIC) colocalize at the microtubule organizing center (MTOC) around the nucleus in a polarized manner facing the leading pole of cerebellar granule cells with a migratory morphology. In neurons with stationary morphology, NudC is distributed throughout the soma and colocalizes with CDIC and tubulin in neurites as well as at the MTOC. At the subcellular level, NudC, CDIC, and p150 dynactin colocalize to the interphase microtubule array and the MTOC in fibroblasts. The observed colocalization is confirmed biochemically by coimmunoprecipitation of NudC with CDIC and cytoplasmic dynein heavy chain (CDHC) from mouse brain extracts. Consistent with its expression in individual neurons, a high level of NudC is detected in regions of the embryonic neocortex undergoing extensive neurogenesis as well as neuronal migration. These data suggest a biochemical and functional interaction of NudC with Lis1 and the dynein motor complex during neuronal migration in vivo.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2001

Androgen regulation of the cell-cell adhesion molecule-1 (Ceacam1) gene.

Previous studies have established that the cell-cell adhesion molecule-1 (CEACAM1, previously known as C-CAM1) functions as a tumor suppressor in prostate cancer and is involved in the regulation of prostate growth and differentiation. However, the molecular mechanism that modulates CEACAM1 expression in the prostate is not well defined. Since the growth of prostate epithelial cells is androgen-regulated, we investigated the effects of androgen and the androgen receptor (AR) on CEACAM1 expression. Transient transfection experiments showed that the AR can enhance the Ceacam1 promoter activity in a ligand-dependent manner and that the regulatory element resides within a relatively short (-249 to -194 bp) segment of the 5'-flanking region of the Ceacam1 gene. This androgen regulation is likely through direct AR-promoter binding because a mutant AR defective in DNA binding failed to upregulate reporter gene expression. Furthermore, electrophoretic mobility shift assays demonstrated that the AR specifically binds to this sequence, and mutation analysis of the potential ARE sequences revealed a region within the sequence that was required for the AR to activate the Ceacam1 gene. Therefore, the regulation of Ceacam1 gene expression by androgen may be one of the mechanisms by which androgen regulates prostatic function.

Androgens↗
PubMed2001

Dynamics of the spin-boson Hamiltonian by the projection operator technique: applications to electron transfer reactions.

A perturbative treatment developed by using the projection operator technique is provided to find dynamics of the spin-boson Hamiltonian in the second order approximation of the subsystem-bath interaction. In the framework of the generalized master equations and in the Markovian approximation it leads to the Redfield/Bloch-type equations. The treatment can be applied to both fast and slow bath cases; in this paper we consider the fast bath case. The relaxation times, energy splitting, and bath-induced renormalization effect of the coherence frequency are discussed and applied to a Lorentzian-Ohmic fast bath. A good agreement between our results and those obtained by the path-integral formalism is obtained. The treatment is applied to electron transfer reactions to test the possibility of apparition of the electronic coherence in certain photosynthetic reaction centers.

Journal Article↗