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1.
ACS Nano ; 4(5): 2523-30, 2010 May 25.
Article in English | MEDLINE | ID: mdl-20405872

ABSTRACT

A simple biomolecule-assisted hydrothermal approach has been developed for the fabrication of Bi(2)Te(3) thermoelectric nanomaterials. The product has a nanostring-cluster hierarchical structure which is composed of ordered and aligned platelet-like crystals. The platelets are approximately 100 nm in diameter and only approximately 10 nm thick even though a high reaction temperature of 220 degrees C and a long reaction time of 24 h were applied to prepare the sample. The growth of the Bi(2)Te(3) hierarchical structure appears to be a self-assembly process. Initially, Te nanorods are formed using alginic acid as both reductant and template. Subsequently, Bi(2)Te(3) grows in a certain direction on the surface of the Te rods, resulting in the nanostring structure. The nanostrings further recombine side-by-side with each other to achieve the ordered nanostring clusters. The particle size and morphology can be controlled by adjusting the concentration of NaOH, which plays a crucial role on the formation mechanism of Bi(2)Te(3). An even smaller polycrystalline Bi(2)Te(3) superstructure composed of polycrystalline nanorods with some nanoplatelets attached to the nanorods is achieved at lower NaOH concentration. The room temperature thermoelectric properties have been evaluated with an average Seebeck coefficient of -172 microV K(-1), an electrical resistivity of 1.97 x 10(-3) Omegam, and a thermal conductivity of 0.29 W m(-1) K(-1).


Subject(s)
Alginates/chemistry , Bismuth/chemistry , Green Chemistry Technology/methods , Nanostructures/chemistry , Reducing Agents/chemistry , Tellurium/chemistry , Temperature , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Particle Size , Sodium Hydroxide/chemistry , X-Ray Diffraction
2.
Int J Environ Res Public Health ; 4(2): 106-10, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17617673

ABSTRACT

This study aims to classify regions with different air pollution characteristics into groups in Taiwan, and further to evaluate and compare the air quality of various groups. A selected multivariate analysis technique, cluster analysis, is applied to the pollution monitoring dataset which including PM10, SO2, NO2, CO and O3. The obtained results have proved that the regions with similar air pollution characteristic can be appropriately grouped by applying cluster analysis. All 22 regions are classified into six groups, and the pollution pattern for each group is characterized as: Group 1 (high SO2/NO2; low PM10), Group 2 (high PM10), Group 3 (high SO2/PM10), Group 4 (low SO2/NO2/CO; high O3), Group 5 (low CO/NO2; high O3) and Group 6 (low PM10/SO2/NO2/O3/CO). Results from air quality evaluation indicate that the regions in group 6 (Ilan, Hualien and Taitung) have the best air quality while the regions in group 3 (Kaohsiung and Kaohsiung City) have the worst air quality in Taiwan. The results from correlation analysis reveal that incidence of the respiratory system disease is significantly positively correlated with pollution of NO2 and CO at 99% confidence level.


Subject(s)
Air Pollution/adverse effects , Health Status , Lung Diseases/epidemiology , Public Health , Cluster Analysis , Humans , Incidence , Taiwan/epidemiology
3.
Diabetes ; 43(6): 741-5, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8194658

ABSTRACT

The objective of this study is to understand the metabolic and immunologic basis of diabetes in adult blacks with diabetic ketoacidosis (DKA). Twenty-one black adults presenting with DKA ([mean +/- SD] blood pH = 7.18 +/- 0.09, plasma glucose = 693 +/- 208 mg/dl, and positive serum ketones) had a subsequent clinical course of non-insulin-dependent diabetes mellitus (NIDDM). Human leukocyte antigens (HLAs) DR and DQ and antibodies to glutamic acid decarboxylase (GAD) and islet cell cytoplasmic proteins (ICP) were measured to assess autoimmunity. Insulin action was evaluated by the euglycemic insulin clamp, and insulin secretion was measured by C-peptide responses to oral glucose. Ketoacidosis was treated with insulin. Two subjects had a precipitating illness; four had a history of NIDDM. At the time of study, subjects' glycemic control was good (HbA1c = 5.7 +/- 1.6%). Nine subjects were treated with insulin, and 12 were on either sulfonylurea treatment or diet alone. Men (n = 12) were younger than women (n = 9) (40.8 +/- 9.8 and 51.1 +/- 6.3 years of age, respectively, P < 0.05) but similar in body mass index (27.8 +/- 2.7 and 29.98 +/- 4.1 kg/m2, respectively). Antibodies to GAD and ICP were absent. All but one subject was insulin resistant compared with normal subjects (glucose disposal 3.56 +/- 0.04 vs. 6.86 +/- 0.02 mg.kg-1.min-1), and insulin secretion was lower. HLA DR3 and DR4 frequency was higher than in nondiabetic black control subjects (65 vs. 30%, P < 0.012).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Autoantibodies/blood , Diabetes Mellitus, Type 2/immunology , Diabetic Ketoacidosis/immunology , Glutamate Decarboxylase/immunology , HLA-DR3 Antigen/blood , HLA-DR4 Antigen/blood , Adult , Black People/genetics , Blood Glucose/metabolism , C-Peptide/blood , Diabetes Mellitus, Type 2/blood , Diabetic Ketoacidosis/blood , Female , Glucose Tolerance Test , HLA-DQ Antigens/blood , Humans , Male , Middle Aged , Random Allocation , Reference Values , Sex Factors , White People/genetics
4.
Diabetes ; 42(3): 444-9, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8432415

ABSTRACT

NIDDM has been postulated to be a component of a more generalized metabolic syndrome, Syndrome X, caused by insulin resistance. Although the components of the syndrome include glucose intolerance, hypertension, increased TG, and decreased HDL cholesterol, their relationship to insulin resistance and/or hyperinsulinemia is controversial. Recent investigations have shown racial differences in the relationship between insulin resistance and BP in nondiabetic populations. We assessed the relationship between insulin resistance and the other components of the syndrome in 37 black men and 53 black women with NIDDM. Insulin sensitivity was determined by measuring glucose disposal with the euglycemic insulin clamp technique with a 1 mU.kg-1.min-1 insulin infusion. We also determined fasting lipid profiles and BP. In this group of black men and women with NIDDM, 30% were insulin sensitive, and 70% were insulin resistant. No correlation existed between insulin sensitivity and sBP or dBP in either sex. Fasting serum TGs were inversely correlated with insulin sensitivity for both men (r = -0.401, P = 0.02) and women (r = -0.366, P = 0.008). Serum HDL cholesterol was highly correlated with insulin sensitivity for men (r = 0.421, P = 0.01) but not for women (r = 0.071, P = 0.62). Fasting serum TG levels and serum HDL-cholesterol levels were highly correlated in an inverse relationship in men (r = -0.368, P = 0.03), but not women (r = -0.199, P = 0.17). In summary, BP does not correlate with insulin resistance in blacks with NIDDM. Normal insulin sensitivity occurs in 33% of black men and 25% of black women with NIDDM.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Black People , Diabetes Mellitus, Type 2/physiopathology , Insulin Resistance/physiology , Adult , Aged , Blood Pressure/physiology , Cholesterol, HDL/blood , Diabetes Mellitus, Type 2/ethnology , Diabetes Mellitus, Type 2/metabolism , Fasting , Female , Glucose/metabolism , Humans , Liver/metabolism , Male , Middle Aged , Regression Analysis , Syndrome
5.
Diabetes Care ; 14(11): 1036-42, 1991 Nov.
Article in English | MEDLINE | ID: mdl-1797484

ABSTRACT

OBJECTIVE: We had previously shown two variants among black non-insulin-dependent diabetic (NIDDM) subjects in a normoglycemic remission: one with insulin resistance and the other with normal insulin sensitivity. This study examined whether these two variants exist in the ordinary hyperglycemic black NIDDM population. RESEARCH DESIGN AND METHODS: Fifty-two black NIDDM subjects were assessed for insulin-stimulated glucose disposal (euglycemic clamp), glycemic control (fasting plasma glucose and HbA1c), and fasting lipid profiles. RESULTS: The distribution of glucose disposal in 30 black NIDDM subjects (body mass index; BMI less than 30 kg/m2) was bimodal, which indicated two populations. Eighteen of 30 subjects (BMI 26.4 +/- 0.5 kg/m2) had insulin resistance (glucose disposal 3.21 +/- 0.24 mg.kg-1.min-1). Twelve of 30 subjects (BMI 24.83 +/- 1.1 kg/m2) had normal insulin sensitivity (glucose disposal 7.19 +/- 0.46 mg.kg-1.min-1). Twenty-one of the remaining 22 subjects (BMI 33.4 +/- 0.7 kg/m2) were insulin resistant (glucose disposal 2.88 +/- 0.21 mg.kg-1.min-1). Fasting serum triglyceride levels were lowest in the insulin-sensitive population (0.91 +/- 0.07 mM) and different from the insulin-resistant population, BMI less than 30 and greater than 30 kg/m2, (1.20 +/- 0.10 mM, P less than 0.05 and 1.42 +/- 0.17 mM, P less than 0.025, respectively). Fasting serum low-density lipoprotein cholesterol levels were not significantly different among the groups, although it did increase with insulin resistance and increasing obesity. Total serum cholesterol levels and glycemic control were similar for all three groups. Serum high-density lipoprotein cholesterol levels were higher in women compared with men. CONCLUSIONS: In the hyperglycemic black NIDDM population, two variants exist: one with insulin resistance and one with normal insulin sensitivity. This insulin-sensitive variant represents 40% of subjects with a BMI less than 30 kg/m2. Moreover, the insulin-sensitive group has a lower risk profile for cardiovascular disease.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Lipids/blood , Adult , Analysis of Variance , Black People , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Fasting , Female , Glucose Clamp Technique , Glycated Hemoglobin/analysis , Humans , Insulin/pharmacology , Insulin Resistance , Male , Middle Aged , New York City , Sex Characteristics , Triglycerides/blood
6.
Cardiovasc Intervent Radiol ; 10(2): 92-5, 1987.
Article in English | MEDLINE | ID: mdl-3107834

ABSTRACT

Nine patients with 10 episodes of acute axillary-subclavian vein thrombosis were treated with local low-dose streptokinase infusion. All patients except one were heparinized during the procedure with conversion to oral anticoagulation upon completion of the infusion. Recanalization was achieved in 7 patients (70%). Thrombosis recurred in 1, and in 2 patients the procedure was unsuccessful. No major complications were encountered. We concluded that local low-dose streptokinase infusion is a safe, simple, and effective method for treating acute axillary-subclavian vein thrombosis.


Subject(s)
Axillary Vein , Streptokinase/therapeutic use , Subclavian Vein , Thrombosis/drug therapy , Adult , Aged , Female , Humans , Infusions, Intravenous , Male , Middle Aged , Streptokinase/administration & dosage
8.
Lasers Surg Med ; 1(1): 93-101, 1980.
Article in English | MEDLINE | ID: mdl-7038361

ABSTRACT

Thirty people with classical or definite rheumatoid arthritis received laser exposure to a Q-switch neodymium laser that operated at 1.06 micrometer with an output of 15 joules/cm2 for 30 nsec. One hand was lased at the proximal interphalangeal (PIP) and metacarpal phalangeal (MCP) joints, whereas the other hand was sham lased. The patient, physician, and occupational therapy evaluators did not know which hand was being lased. Twenty-one patients noted improvement of both their MCP and PIP joints of both hands during laser therapy. Twenty-seven noted improvement of their PIP joints and 26 noted improvement of the MCP joints during therapy. Heat, erythema, pain, swelling, and tenderness all improved with time in both hands, but the lased hand had more significant improvement in erythema and pain. There was also significant improvement in grasp and tip pressure on the lased side. The level of circulating immune complexes as measured by platelet aggregation decreased during lasing. The improvement may be related to laser exposure. The exact role that laser radiation has upon rheumatoid arthritis and its mechanism of action remain to be elucidated.


Subject(s)
Arthritis, Rheumatoid/surgery , Laser Therapy , Adult , Aged , Arthritis, Rheumatoid/physiopathology , Clinical Trials as Topic , Female , Finger Joint/physiopathology , Finger Joint/surgery , Humans , Immunosuppression Therapy , Male , Metacarpophalangeal Joint/surgery , Middle Aged
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