Hydroxytelechelic polybutadiene, 12. Polymerization reactions between hydroxytelechelic polybutadiene with hexamethylene diisocyanate or 4,4′-methylenedi(phenyl isocyanate). Kinetics of polymerization in toluene and in the bulk

Addition polymerization of hydroxytelechelic polybutadiene (HTPB) with hexamethylene diisocyanate (HMDI) with a mole ratio NCO/OH = 0,8 in dilute solution of toluene as well as in bulk follows apparent 3rd order kinetics. The polymerization rates are twice as sensitive to temperature as in toluene, an effect which is attributed to intra- and/or intermolecular (OH, OH) auto-association. The three alcoholic functions in HTPB are catalyzed equally by dibutyltin dilaurate. Even with high excess of NCO, free alcoholic functions were found in the product. They were determined quantitatively in moulded polyurethane sheets from HTPB + HMDI and HTPB + 4,4′-methylenedi(phenyl isocyanate) which should be partially crosslinked:     

Low molecular weight poly(imide-amide)s obtained by copolycondensation of 4,4′-methylenedi(phenyl isocyanate), trimellitic anhydride and benzoic acid in N-methyl-2-pyrrolidone, 3. Absolute number-average molecular weights and glass transition temperatures

In depth study of low molecular weight poly(imide-amide)s (PIA) obtained by copolycondensation of 4,4′-methylenedi(phenyl isocyanate), trimellitic anhydride and benzoic acid by ¹H and ¹³C NMR spectroscopy and size-exclusion chromatography allows the determination of their absolute number-average molecular weights M?_{n, abs}. Viscosimetric measurements reveal that, dissolved in N-methyl-2-pyrrolidone, these low molecular weight PIAs should be semi-rigid because of the presence of very short crystalline chains. By using the semi-empirical Fox-Flory relation, the extrapolated glass transition temperature equals 300°C for high molecular weight.     

Fatal avian influenza A (H5N1) in a child presenting with diarrhea followed by coma

In southern Vietnam, a four-year-old boy presented with severe diarrhea, followed by seizures, coma, and death. The cerebrospinal fluid contained 1 white cell per cubic millimeter, normal glucose levels, and increased levels of protein (0.81 g per liter). The diagnosis of avian influenza A (H5N1) was established by isolation of the virus from cerebrospinal fluid, fecal, throat, and serum specimens. The patient's nine-year-old sister had died from a similar syndrome two weeks earlier. In both siblings, the clinical diagnosis was acute encephalitis. Neither patient had respiratory symptoms at presentation. These cases suggest that the spectrum of influenza H5N1 is wider than previously thought.     

Neuromuscular disease: health care accessibility in the Nord-Pas-de- Calais region

A survey was conducted to estimate accessibility to current diagnostic techniques for patients with neuromuscular disease living in the Nord-Pas-de-Calais. In association with the "Association fran?aise contre les myopathies", we invited 200 adults with neuromuscular disease to fill out a questionnaire concerning diagnosis of their neuromuscular disease and medical and paramedical follow-up. Each subject answered the questionnaire anonymously providing data on sociodemographic items, diagnosis and medical and paramedical follow-up. The results showed a lack of follow-up for lung disease whereas respiratory failure is known as a frequent complication of neuromuscular disease. Genetic counselling was not suggested often enough. A large proportion (80 p. 100) of the patients had had physiotherapy. Whereas cardiomyopathy and orthopedic buckling with subsequent decreased autonomy are observed in 90 p. 100 of patients with Duchenne muscular dystrophy, only 42 p. 100 of the patients with this disease were followed by a cardiologist and a physical therapists. We suggest more cooperation between specialists in order to improve medical care for patients with neuromuscular diseases.     

Personality of the parkinsonian. Clinical and psychometric approach

The personality of patients suffering from Parkinson's disease has been considered as the basis of a psychosomatic theory or more simply as a form of reaction. Between these two extremes the controversy continues and is modified by the use of dopaminergic agents. In this study, 30 patients suffering from parkinson's disease undergo a psychological examination and a M.M.P.I.; the results allow us to determine a pre-morbid obsessive personality coupled with agressivity and ambition. A transformation occurs with the arrival of illness; dependence, passivity, suggestibility evolve in a context where anxiety is relieved of all agressivity but acquires a depressive character. The people surrounding the patients play a part in this transformation. Moreover the pre-morbid characteristics of these patients remind the physician of H. Tellenbach's "typus melancholicus".     

Association of KCNJ11 and ABCC8 single-nucleotide polymorphisms with type 2 diabetes mellitus in a Kinh Vietnamese population

Type 2 diabetes mellitus (T2DM) is a genetically influenced disease, but few studies have been performed to investigate the genetic basis of T2DM in Vietnamese subjects. Thus, the potential associations of KCNJ11 and ABCC8 single nucleotide polymorphisms (SNPs) with T2DM were investigated in a Kinh Vietnamese population. A cross-sectional study consisting of 404 subjects including 202 T2DM cases and 202 non-T2DM controls was designed to examine the potential associations of 4 KCNJ11 and ABCC8 SNPs (rs5219, rs2285676, rs1799859, and rs757110) with T2DM. Genotypes were identified based on restriction fragment length polymorphism and tetra-primer amplification refractory mutation system polymerase chain reaction. After statistically adjusting for age, sex, and BMI, rs5219 was found to be associated with an increased risk of T2DM under 2 inheritance models: codominant (OR = 2.15, 95% confidence intervals [CI] = 1.09–4.22) and recessive (OR = 2.08, 95%CI = 1.09–3.94). On the other hand, rs2285676, rs1799859, and rs757110 were not associated with an increased risk of T2DM. Haplotype analysis elucidated a strong linkage disequilibrium between the 3 SNPs, rs5219, rs2285676, and rs757110. The haplotype rs5219(A)/rs2285676(T)/rs757110(G) was associated with an increased risk of T2DM (OR = 1.42, 95%CI = 1.01–1.99). The results show that rs5219 is a lead candidate SNP associated with an increased risk of developing T2DM in the Kinh Vietnamese population. Further functional characterization is needed to uncover the mechanism underlying the potential genotype-phenotype associations.     

The value of quantitative magnetic resonance imaging signal intensity in distinguishing between spinal meningiomas and schwannomas

Background: Prior studies have suggested a number of the subjective visual characteristics that help distinguish between spinal meningiomas and schwannomas on magnetic resonance imaging and computed tomography; however, objective quantification of the signal intensity can be useful information. This study assessed whether quantitative magnetic resonance imaging (MRI) signal intensity (SI) measurements could distinguish intradural-extramedullary schwannomas from meningiomas.Methods: From July 2019 to September 2021, 54 patients with intradural-extramedullary tumors (37 meningiomas and 17 schwannomas) underwent surgery, and tumors were verified pathologically. Defined regions of interest were used to quantify SI values on T1- (T1W) and T2-weighted images (T2W). Receiver operating characteristic curve analysis was used to obtain cutoff values and calculate the area under the curve (AUC), sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV).Results: Both Maximum (T2_max) and mean (T2_mean) T2W SI values demonstrated outstanding (AUC: 0.91) abilities to differentiate meningiomas from schwannomas with Se, Sp, PPV, and NPV values of 94.6%, 70.6%, 87.5%, and 85.7%, respectively, for T2_max and 81.1%, 88.2%, 93.8%, and 68.2% for T2_mean. The maximum SI value on contrast-enhanced T1W (T1CE_max) and the T2W tumor: fat SI ratio (rTF) demonstrated acceptable abilities (AUC: 0.73 and 0.79, respectively) to differentiate meningiomas from schwannomas with Se, Sp, PPV, and NPV values of 94.6%, 70.6%, 87.5%, and 85.7%, respectively, for T1CE_max and 81.1%, 88.2%, 93.8%, and 68.2% for rTF.Conclusions: Quantitative SI values (T2_max, T2_mean, T2_min, T1CE_max, rTF) can be used to differentiate intradural-extramedullary schwannomas from meningiomas.     

One-step hydrothermal preparation of Ta-doped ZnO nanorods for improving decolorization efficiency under visible light

In this work, Ta-doped ZnO (Ta-ZnO) nanomaterials were synthesized by the hydrothermal method at different temperatures (110, 150, and 170 °C) for the photodegradation of methylene blue (MB) under visible light. Ta doping significantly affects the crystal defects, optical properties, and MB photocatalytic efficiency of ZnO materials. The optical absorption edge of Ta-ZnO 150 was redshifted compared to undoped ZnO, correlating to bandgap narrowing (E_gTa–ZnO = 2.92 eV; E_gZnO = 3.07 eV), implying that Ta doped ZnO is capable of absorbing visible light. Besides, Ta-doping was the reason for enhanced blue light emission in the photoluminescence spectrum, which is related to the oxygen defect V⁰_O. It is also observed in the XPS spectra, where the percentage of oxygen in the oxygen-deficient regions (O_531.5 eV) of Ta-ZnO150 is higher than that of ZnO150. It is an important factor in enhancing ZnO''s photocatalytic efficiency. The MB degradation efficiency of Ta-doped ZnO reached the highest for Ta-ZnO 150 and was 2.5 times higher than ZnO under a halogen lamp (HL). Notably, the influence of hydrothermal temperature on the structural, morphological, and photoelectrochemical properties was discussed in detail. As a result, the optimal hydrothermal temperature for synthesizing the nanorod is 150 °C. Furthermore, photocatalytic experiments were also performed under simulated sunlight and natural sunlight. The nature of the photo-oxidative degradation of MB was also investigated.

The Ta doped ZnO nanorods (Ta-ZnO) were synthesized by a hydrothermal method at different temperatures (110, 150, and 170 °C) for the photodegradation of methylene blue (MB) under visible light.