Electrochemical determination of extractives in wood pulp

The objective of this thesis is to establish electrochemical techniques for the qualitative and quantitative determination of pentacyclic triterpenes in wood extractives. These triterpenes, found in wood extractives, possess beneficial biological effects. However, in the context of paper production, their presence can be problematic due to their lipophilic nature, which can reduce paper strength and hinder subsequent processing steps such as the adhesion of coatings and inks. Among the pentacyclic triterpenes, betulin is the most abundant molecule present up to 30% of the dry weight in a Scandinavian species (B. verrucosa) [1, 2]. To address the challenges associated with handling such compounds in paper mills, betulin and stearic acid were chosen as model compounds. This thesis introduces two distinct characterization techniques: potentiometric sensors in combination with principal component analysis, and voltammetric methods including square wave voltammetry and differential pulse voltammetry. Using ion-selective electrodes and principal component analysis the classification between samples containing KCl, KCl and ethanol and KCl, ethanol and betulin was possible. For voltammetric methods, a glassy carbon electrode with an in-situ lead film was used. Both the aqueous and organic solvents were used as media. The solvent used for preparing the standard solution significantly influenced the square wave voltammograms recorded in alkaline media. Therefore, Tris-HCl buffer (pH 7.4) was used as the medium, and dimethyl sulfoxide served as the solvent for the standard solution. The oxidation signal at 1.6 V for betulinic acid, oleanolic acid, and betulin was found to be proportional to the concentration when 5 mM of the stock solution was added. Additionally, differential pulse voltammograms were recorded using 0.1M tetrabutylammonium hexafluorophosphate in acetonitrile considering the benefits such as a wider electrochemical window and compatibility with organic molecules. The preconcentration step enables the detection of analytes with higher signals compared to the DMSO blank. The imperfect proportionality between peak current and analyte concentration, indicated by the similarity in current signals obtained from 0.5 mM working solution and 5 mM stock solution, remained unresolved. Nonetheless, the obtained results demonstrated that higher concentrations of the stock solution yielded higher current signals when compared to the most diluted standard solution and solvent blank. Furthermore, the extracted birch and conifer samples were analysed affirming the method's capability to detect compounds of interest. The outcomes of this study highlight the validity of employing ISEs in combination with chemometric data treatment for the qualitative determination of betulin, and the potential of the voltammetric methods to detect pentacyclic triterpenes in various electrolytes. However, to validate the reliability of the voltammetric methods, it is imperative to undertake further investigations by repeating experiments in non-aqueous electrolytes aiming to discover the underlying causes of the imperfect proportionality. Notably, it is crucial to determine the concentration of analytes by an independent method after chromatographic separation in natural sample analysis

Persistence and viable but non-culturable state induced by streptomycin in Erwinia amylovora

Persister cell and viable but non-culturable (VBNC) state of bacteria are survival strategies against antibiotics and various environmental stresses, respectively, but they tend to be ignored in agriculture fields, even though bacteria can regain their abilities to survive and produce disease once those stresses disappear. This study was carried out to determine whether persister cell and VBNC state in Erwinia amylovora are present after exposures to streptomycin, the length of their persistence, and the steps needed to decrease the inoculum. Persister cells were observed using biphasic killed growth curve for 4–8 h when the late stationary phase cells of E. amylovora were cultured in liquid medium containing streptomycin. This state was maintained for up to 12 h based on the colony forming units (CFUs) of the colonies that grew on the mannitol glutamate yeast extract (MGY) medium after streptomycin was removed. The CFUs on the MGY medium were lower than the total count determined using the LIVE/DEAD Kit, suggesting that persister cells and VBNC state might co-exist for up to 12 h after exposure to streptomycin. However, after 12 h, E. amylovora cells did not continue to grow on the medium for 9 days, suggesting that they entered a VBNC state at that time and remained in a persistent state. In addition, based on the Redox Sensor Green staining method, the presence of both states was confirmed for up to 12 h, and only then did the VBNC state became apparent. Furthermore, persister cells were observed for up to 24 h, and damaged cells reduced when E. amylovora cells were culture in distilled water with streptomycin, indicating that the uptake of lower nutrients in E. amylovora led to prolonged persister cells and VBNC state, which are more likely to survive after streptomycin treatments. The addition of sucrose and oxytetracycline to distilled water containing streptomycin reduced persister cells than other sources did. Thus, to inhibit the spread of fire blight, management techniques must consider the hazards of using streptomycin treatments that induce dormancy, such as persister cells and VBNC state, beyond the development of resistant strain

Health-related quality of life with KDQOL-36 and its association with self-efficacy and treatment satisfaction in Korean dialysis patients

BACKGROUND AND OBJECTIVES: This study was conducted to measure the level of health-related quality of life (HRQOL) and to reveal the association of self-efficacy and treatment satisfaction with it in Korean dialysis patients. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: The study subjects were 237 patients receiving either hemodialysis (HD) or peritoneal dialysis (PD) from two university hospitals, from February to June in 2010. We investigated HRQOL using the Korean version of Kidney Disease Quality of Life Short Form 36 (KDQOL-36), and self-efficacy and treatment satisfaction by self-administrative questionnaire and their dialysis-related variables by reviewing clinical records. The associations of self-efficacy and treatment satisfaction with HRQOL were assessed using multiple linear regression analysis. RESULTS: The mean HRQOL results were as follows: Physical component score (PCS) was 39.1 ± 8.5, Mental component score (MCS) 44.6 ± 6.8, symptom/problem list was 67.6 ± 17.1, effects of disease score was 58.5 ± 19.6, and burden of disease score was 41.1 ± 28.4. Between PD and HD patients, we could find significant difference only in the symptom/problem list. After removing confounder’s effects by multivariate analysis, respectively, treatment goal self-efficacy and treatment management self-efficacy were significantly related with all 5 domains, except PCS. Treatment satisfaction was significantly related with PCS, MCS, and effects of kidney disease. CONCLUSIONS: Patients’ self-efficacy and treatment satisfaction could influence their HRQOL. Regular and systematic monitoring using KDQOL-36 and interventions to increase self-efficacy and treatment satisfaction should be considered in dialysis care in Korea

Activation of Protein Kinase G After Repeated Cocaine Administration Is Necessary for the Phosphorylation of α-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Receptor GluA1 at Serine 831 in the Rat Nucleus Accumbens

Phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the striatum plays a crucial role in regulating the receptor-coupled signaling cascades leading to behavioral changes associated with psychostimulant exposure. The present study determined if activation of protein kinase G (PKG) contributes to the phosphorylation of AMPA receptor GluA1 subunit at the position of serine 831 (GluA1-S831) in the rat nucleus accumbens (NAc) after repeated cocaine administration. The results demonstrated that repeated intraperitoneal (i.p.) injections of cocaine (20 mg/kg) once a day for seven consecutive days significantly increased the level of phosphorylated (p)GluA1-S831. This increase was decreased by the intra-NAc infusion of either the cyclic guanosine monophosphate (cGMP) analog, Rp-8-Br-PET-cGMPS (5 nmol/1 μL), or the PKG inhibitor, KT5823 (2 nmol/1 μL). Repeated cocaine administration increased PKG binding activity to GluA1. This increase in GluA1-S831 phosphorylation after repeated cocaine administration was decreased by the intra-NAc infusion of the synthetic peptide (Tat-tagged interfering peptide (Tat-GluA1-i)), that interferes with the binding of PKG to GluA1. Intra-NAc infusion of the interfering peptide also reduced the repeated cocaine-induced increase in locomotor activity. These findings suggest that activated PKG, after repeated exposure to cocaine, binds to AMPA receptor GluA1 and is required for the phosphorylation of S831, contributing to behavioral changes

Genome shotgun sequencing and development of microsatellite markers for gerbera (Gerbera hybrida H.) by 454 GS-FLX

The objective of this research was to develop and characterize microsatellite markers for gerbera. We used shotgun sequencing with Roche 454 GS-FLX Titanium technology to identify microsatellite loci in gerbera genomic DNA (Gerbera hybrida). The total length of non-redundant sequences obtained was 22,527,019 bp, which consisted of 3,085 contigs and 28,249 singletons. We assembled 61,958 reads into 3,085 contigs, of which 114 (3.70%) contained microsatellite repeats. The average G+C content was 39.3%. Functional annotation to known sequences yielded 14.7% unigenes in the ‘Raon’ cultivar. Analysis of the gerbera genome DNA (‘Raon’) general library showed that sequences of (AT), (AG), (AAG) and (AAT) repeats appeared most often, whereas (AC), (AAC) and (ACC) were the least frequent. Primer pairs were designed for 80 loci. Only eight primer pairs produced reproducible polymorphic bands in the 28 gerbera accessions analyzed. A total of 30 alleles were identified from the eight polymorphic SSR loci, with two to eight alleles per locus (average level of 3.75). These markers will be useful for investigating genetic diversity and differentiation in gerbera. Keywords: Genetic diversity, genomics, microsatellite isolation, pyrosequencing, SSRs. African Journal of Biotechnology Vol. 11(29), pp. 7388-7396, 10 April, 201

Clinical relevance of ground glass opacity in 105 patients with miliary tuberculosis

SummaryBackgroundAfter the application of chest computed tomography (CT), ground glass opacity (GGO) was introduced as one of major accompanying findings of miliary tuberculosis (MT) in addition to miliary nodules. However, little is known about whether GGO is associated with the clinical manifestations and outcomes of MT. Therefore, the present study examined the clinical relevance of GGO in patients with MT.MethodsChest radiographs and CT scans of MT patients were retrospectively reviewed. Clinical manifestations and outcomes were compared in terms of the extent of GGO revealed by chest CT.ResultsConfirmed 105 MT patients were included. GGO was observed in 70 (67%) patients. MT patients with an extent of GGO >50% (n = 21) had symptoms of shorter duration, more frequent dyspnea, and more pronounced changes in the levels of acute phase reactants. Miliary nodules were less discernible on CT in those with an extent of GGO >50%. MT patients with an extent of GGO >50% were significantly associated with a longer hospital stay (p = 0.02) and with acute respiratory failure (p < 0.001) than those with an extent of GGO ≤50%. However, mortality among MT patients was not associated with the extent of GGO.ConclusionMT patients with an extent of GGO >50% had more rapidly progressive manifestations and a greater potential for delayed diagnosis and poorer prognosis. Nevertheless, mortality was not higher in confirmed MT patients with an extent of GGO >50% than in those with an extent of GGO ≤50%

Changes in the Prevalence of Childhood Asthma in Seoul from 1995 to 2008 and Its Risk Factors

PURPOSE: To investigate the prevalence of asthma and determine its risk factors in elementary school students in Seoul. METHODS: A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to survey 4,731 elementary school students from five areas in Seoul between April and October, 2008. RESULTS: In elementary school children, the lifetime and recent 12-month prevalence of wheezing were 11.7% and 5.6%, respectively. The lifetime prevalence of asthma diagnosis was 7.9%, and the recent 12-month prevalence of asthma treatment was 2.7%. Male sex (adjusted odds ratio [aOR], 1.90; 95% confidence interval [CI], 1.36-2.66), history of atopic dermatitis (AD) (aOR, 2.76; 95% CI, 1.98-3.84), history of allergic rhinitis (AR) (aOR, 3.71; 95% CI, 2.61-5.26), history of bronchiolitis before 2 years of age (aOR, 2.06; 95% CI, 1.39-3.07), use of antibiotics during infancy for >3 days (aOR, 1.88; 95% CI, 1.35-2.62), parental history of asthma (aOR, 2.83; 95% CI, 1.52-5.27), exposure to household molds during infancy (aOR, 1.84; 95% CI, 1.18-2.89), and the development or aggravation of asthma symptoms within 6 months after moving to a new house (aOR, 11.76; 95% CI, 5.35-25.86) were the independent risk factors for wheezing within 12 months. CONCLUSIONS: The prevalence of wheezing and asthma in elementary school students in 2008 was similar to that in the past decade. Male sex, history of AD, history of AR, history of bronchiolitis before 2 years of age, parental asthma, use of antibiotics during infancy, exposure to molds in the house during infancy, and development or aggravation of asthma symptoms within 6 months after moving to a new house, could be risk factors for wheezing within 12 months.ope

A Case of Non-Hodgkin's Lymphoma in Patient with Coombs' Negative Hemolytic Anemia and Idiopathic Thrombocytopenic Purpura

Coombs' negative autoimmune hemolytic anemia (AIHA) is a rare disease which shares similar clinical and hematological features with Coombs' positive AIHA, but its exact frequency remains unknown. There have been few reports of idiopathic thrombocytopenic purpura (ITP) and Coombs' negative AIHA associated with other lymphoproliferative disorders (LPDs). Since there is a well known association between LPDs and autoimmune phenomena, it is important to investigate the possibility of an underlying malignancy. We report a case of ITP and Coombs' negative AIHA associated with diffuse large B-cell lymphoma