Polyvinylidene Fluoride (PVDF)/Polyacrylonitrile (PAN)/Carbon Nanotube Nanocomposites for Energy Storage and Conversion.

Polyvinylidene fluoride (PVDF)/Polyacrilonitrile (PAN)/Multiwalled nanotubes functionalized COOH (MWNT-COOH) nanocomposites with different contents of MWNTs were fabricated by using electrospinning and solution cast methods. The interaction of the MWNTs with the polymer blend was confirmed by a Fourier transform infrared (FTIR) spectroscopy study. The dispersion of the MWNTs in the polymer blend was studied by scanning electron microscopy. The impedance and electrical conductivity of PVDF-PAN/CNTs in a wide frequency range at different temperatures have been studied. The effect of the concentration of the filler on the conductivity of the polymer composite was discussed. Nanocomposites based on PVDF/PAN and MWNTs as filler, show a significant enhancement in the electrical conductivity as a function of temperature.

Micro Structure of Injection Molding Machine Mold Clamping Mechanism: Design and Motion Simulation.

With the advent of intelligence, more and more machines and devices involve the creation of complex structures. In the intelligent manufacturing industries, moldings including injection molding, blow molding, compression molding and others play critical roles in manufacturing the highly precise parts required for building intelligent machines (such as computers, cell phones, robots, etc.). The performance of the clamping mechanism directly affects the quality of the microstructure of injection products. The design of injection molding mold clamping mechanism is based on the microstructure characteristics of the trip of toggle lever mechanism ratio, speed ratio, and force amplification ratio. These are used to study the main performance parameters, such as analysis, as well as for the establishment of the physical model of the clamping mechanism. The model is based on the microstructure of injection of hyperbolic elbow clamping mechanism kinematics simulation. Simulation results and the theoretical calculation contrast analysis shows that the maximum dynamic template speed is 215.34 mm/s. The dynamic templates and crosshead speed ratio is 2.15, therefore the design of injection molding mold clamping mechanism for microstructure provides favorable technical support. The method described here is important to build complicated molds required to build highly precise parts to build intelligent machineries.

Human leukocyte antigen class I allelic and haplotype loss in squamous cell carcinoma of the head and neck: clinical and immunogenetic consequences.

The expression of human leukocyte antigen (HLA) class I molecules on the cell surface is necessary for the presentation of peptide antigens to cytotoxic CD8+ T lymphocytes of the immune system. Down-regulation of HLA class I gene expression has been implicated in tumorigenesis, including squamous cell carcinoma of the head and neck (SCCHN). Loss of MHC class I antigens may be one mechanism by which tumor cells escape immune detection. We performed prospective immunostaining of 26 primary SCCHN tumors and samples of normal mucosa harvested several centimeters away from the primary tumor, using a large panel of antibodies directed against allele-specific as well as monomorphic determinants of HLA class I molecules. Loss of expression of HLA class I proteins in the tumor was found in 50% (13 of 26) of primary tumors and was highly correlated with HLA loss in the corresponding normal mucosa (P < 0.0001). Further analysis demonstrated that the loss of HLA class I expression in the tumor was significantly associated with regional lymph node metastases (nodal stage; P = 0.0388), and that the number of HLA class I alleles lost in the normal mucosa was associated with subsequent development of a new primary aerodigestive tract cancer (P = 0.042). A patient with two metachronous cancers available for analysis had no evidence of HLA loss in the first tumor, demonstrated allelic loss in the second cancer, and subsequently died of disease. These results suggest that the loss of expression of HLA class I alleles may have prognostic implications.

Studies of HLA-DR and DQ alleles in systemic sclerosis patients with autoantibodies to RNA polymerases and U3-RNP (fibrillarin).

OBJECTIVE: To determine the clinical and immunogenetic features of systemic sclerosis (SSc) patients with anti-RNA polymerase (RNAP) or anti-fibrillarin antibodies. METHODS: DNA typing for HLA-DR and DQ alleles was performed in 292 patients with SSc, including 81 with anti-RNAP and 24 with anti-fibrillarin antibodies. The remaining patients had anti-topoisomerase I (anti-topo I; 71), anti-centromere (ACA; 56), anti-Th/To (28), or other antinuclear (32) antibodies. RESULTS: Significant associations were observed in the patients with anti-topo I, ACA, and anti-Th/To antibodies, similar to those previously reported. No significant HLA associations were detected in the 81 patients with anti-RNAP. although weak associations were noted when this group was subdivided on the basis of immunofluorescence staining pattern; i.e., HLA-DR4 was increased in patients with strong nucleolar staining and HLA-DR3 was more frequent in patients with nucleoplasm staining only. No HLA-DR or DQ associations were observed in 24 patients with anti-fibrillarin antibodies. CONCLUSION: The identification of HLA associations in SSc patients with anti-RNAP antibodies may only be possible when the individual antibody specificities recognized by these sera are identified. It may then be possible to classify these patients into distinct clinical and immunogenetic subgroups.

HLA and clinical associations in systemic sclerosis patients with anti-Th/To antibodies.

OBJECTIVE: To determine the clinical and immunogenetic features of systemic sclerosis (SSc) patients with anti-Th/To autoantibodies. METHODS: HLA class II alleles were determined by DNA oligotyping in a large group of SSc patients with anticentromere antibodies (ACA), anti-topoisomerase I (anti-topo I), and anti-Th/To autoantibodies. RESULTS: Clinical features of the 28 anti-Th/To-positive SSc patients were similar to those observed in the 56 ACA-positive SSc patients, except for a decreased frequency of gastrointestinal involvement in anti-Th/To-positive patients. Immunogenetic analysis revealed a significant increase in the frequency of HLA-DR11 in the anti-Th/To-positive and the anti-topo I-positive patients. The anti-Th/To-positive patients also had a significant reduction in the frequency of HLA-DR7, similar to that seen in ACA-positive SSc patients. CONCLUSION: Despite clinical and immunogenetic similarities with both the ACA- and anti-topo I-positive patients, anti-Th/To-positive SSc patients present a characteristic pattern of clinical and immunogenetic features that may have implications regarding etiology, pathogenesis, and treatment.

HLA and ethnic associations among systemic sclerosis patients with anticentromere antibodies.

SSc with ACAs is characterized by limited cutaneous involvement and, in most patients, a mild protracted course. We have studied 104 SSc patients, 47 with ACAs and 57 who were negative for both ACAs and anti-topo I antibodies, for HLA-DR and -DQ associations using DNA typing techniques. Normal controls consisted of 181 healthy individuals. A significant association was observed in the ACA-positive patients with DQB1-0501 (p = 0.001, RR 2.6). There was also a significant decrease in the frequency of DQB1-0201 (p = 0.01, RR 0.33). In addition, the ACA-positive SSc patients were significantly different ethnically from both the other SSc patients and the normal controls (p = 0.004). When patients were stratified according to their ethnic origin and the analysis of HLA associations was repeated, the HLA associations persisted. These results strongly suggest that the development of SSc with ACAs is associated with particular DQB1 alleles, and also that ethnic origin plays a role in disease susceptibility.

Serum magnesium levels in asthmatic patients during acute exacerbations of asthma.

The purpose of this study was to determine whether serum magnesium levels in asthmatic patients during acute exacerbations differ from those of a control population. Twenty-three known asthmatics presenting to the emergency department in acute exacerbation (cases) and 15 nonasthmatic patients (controls) matched for age, sex, race, and socioeconomic status had serum magnesium assays drawn. Admission criteria were: age 18 to 50 years with no history of alcoholism, heart disease, renal disease, or diuretic use. Patients giving a history of pregnancy were excluded. Serum magnesium levels were not significantly different in the two study populations, nor did they correlate with the severity of asthma (mean values: cases, 2.04 +/- 0.159 versus controls, 2.03 +/- 0.134 mg/dL; SD of the difference of the means = .048). An analysis for beta-error demonstrated the true difference of the means to be less than .1 (95% confidence) or less than .13 (99% confidence). In conclusion, serum magnesium levels in asthmatics are not significantly different from those of a control nonasthmatic population. They are not clinically useful for predicting the severity of disease.

Violence in families of adolescent runaways.

Adolescents who run away from home frequently give many reasons for their behavior, but rarely has an examination of physical maltreatment as a precipitating factor for leaving home been carefully conducted. The Conflict Tactics Scale, a measure of how families resolve conflicts, was completed by 199 adolescents who ran away to a youth shelter. Some 78% of the adolescents self-reported significant physical violence directed toward themselves by a parent in the one year prior to their running away. There were no significant effects of age or sex on the amount of physical violence. A comparison between runaway adolescents and adolescents labeled abused reveals no significant differences in at-risk child abuse scores. An argument is presented for crisis counselors and youth shelter workers to more carefully examine and treat family violence in adolescents who run.