Natural and synthetic fibres improving tensile strength and elongation of paper products

The theory part of the Master’s thesis introduces fibres with high tensile strength and elongation used in the production of paper or board. Strong speciality papers are made of bleached softwood long fibre pulp. The aim of the thesis is to find new fibres suitable for paper making to increase either tensile strength, elongation or both properties. The study introduces how fibres bond and what kind of fibres give the strongest bonds into fibre matrix. The fibres that are used the in manufacturing of non-wovens are long and elastic. They are longer than softwood cellulose fibres. The end applications of non-wovens and speciality papers are often the same, for instance, wet napkins or filter media. The study finds out which fibres are used in non-wovens and whether the same fibres could be added to cellulose pulp as armature fibres, what it would require for these fibres to be blended in cellulose, how they would bind with cellulose and whether some binding agents or thermal bonding, such as hot calendaring would be necessary. The following fibres are presented: viscose, polyester, nylon, polyethylene, polypropylene and bicomponent fibres. In the empiric part of the study the most suitable new fibres are selected for making hand sheets in laboratory. Test fibres are blended with long fibre cellulose. The test fibres are viscose (Tencel), polypropylene and polyethylene. Based on the technical values measured in the sheets, the study proposes how to continue trials on paper machine with viscose, polyester, bicomponent and polypropylene fibres.

Development of simple and efficient synthetic strategies for production of fine chemicals of pharmaceutical relevance : metal-mediated allylation combined with applied catalysis

Den snart 200 år gamla vetenskapsgrenen organisk synteskemi har starkt bidragit till moderna samhällens välfärd. Ett av flaggskeppen för den organiska synteskemin är utvecklingen och produktionen av nya läkemedel och speciellt de aktiva substanserna däri. Därmed är det viktigt att utveckla nya syntesmetoder, som kan tillämpas vid framställningen av farmaceutiskt relevanta målstrukturer. I detta sammanhang är den ultimata målsättningen dock inte endast en lyckad syntes av målmolekylen, utan det är allt viktigare att utveckla syntesrutter som uppfyller kriterierna för den hållbara utvecklingen. Ett av de centralaste verktygen som en organisk kemist har till förfogande i detta sammanhang är katalys, eller mera specifikt möjligheten att tillämpa olika katalytiska reaktioner vid framställning av komplexa målstrukturer. De motsvarande industriella processerna karakteriseras av hög effektivitet och minimerad avfallsproduktion, vilket naturligtvis gynnar den kemiska industrin samtidigt som de negativa miljöeffekterna minskas avsevärt. I denna doktorsavhandling har nya syntesrutter för produktion av finkemikalier med farmaceutisk relevans utvecklats genom att kombinera förhållandevis enkla transformationer till nya reaktionssekvenser. Alla reaktionssekvenser som diskuteras i denna avhandling påbörjades med en metallförmedlad allylering av utvalda aldehyder eller aldiminer. De erhållna produkterna innehållende en kol-koldubbelbindning med en närliggande hydroxyl- eller aminogrupp modifierades sedan vidare genom att tillämpa välkända katalytiska reaktioner. Alla syntetiserade molekyler som presenteras i denna avhandling karakteriseras som finkemikalier med hög potential vid farmaceutiska tillämpningar. Utöver detta tillämpades en mängd olika katalytiska reaktioner framgångsrikt vid syntes av dessa molekyler, vilket i sin tur förstärker betydelsen för de katalytiska verktygen i organiska kemins verktygslåda.

Repair of the anophthalmic cavity of rats with synthetic hydroxyapatite

We placed spheres of synthetic hydroxyapatite (calcium chloride combined with sodium phosphate) in the eviscerated or enucleated orbital cavity of rats in order to evaluate the biocompatibility of this material with the orbital cavity. The study was conducted on 50 albino rats, 25 of which were submitted to enucleation and 25 to evisceration of one eye. The animals were sacrificed 7, 15, 21, 30 and 60 days after surgery and the orbital content was submitted to histopathological examination. A reaction of the young granulation tissue type was observed first. The hydroxyapatite was gradually surrounded by a granulomatous macrophage inflammatory response and covered with dense connective tissue that formed a sort of" mesh" septating and supporting progressively smaller blocks of the substance. The same type of reaction was observed in the enucleated and eviscerated cavities. We conclude that synthetic hydroxyapatite is an inert nonallergenic material which is appropriate for volume replacement in the anophthalmic cavity

Transgenic animal models for the functional analysis of vasoactive peptides

The interplay of vasoactive peptide systems is an essential determinant of blood pressure regulation in mammals. While the endothelin and the renin-angiotensin systems raise blood pressure by inducing vasoconstriction and sodium retention, the kallikrein-kinin and the natriuretic-peptide systems reduce arterial pressure by eliciting vasodilatation and natriuresis. Transgenic technology has proven to be very useful for the functional analysis of vasoactive peptide systems. As an outstanding example, transgenic rats overexpressing the mouse Ren-2 renin gene in several tissues become extremely hypertensive. Several other transgenic rat and mouse strains with genetic modifications of components of the renin-angiotensin system have been developed in the past decade. Moreover, in recent years gene-targeting technology was employed to produce mouse strains lacking these proteins. The established animal models as well as the main insights gained by their analysis are summarized in this review.

Guanylin peptides: cyclic GMP signaling mechanisms

Guanylate cyclases (GC) serve in two different signaling pathways involving cytosolic and membrane enzymes. Membrane GCs are receptors for guanylin and atriopeptin peptides, two families of cGMP-regulating peptides. Three subclasses of guanylin peptides contain one intramolecular disulfide (lymphoguanylin), two disulfides (guanylin and uroguanylin) and three disulfides (E. coli stable toxin, ST). The peptides activate membrane receptor-GCs and regulate intestinal Cl- and HCO3- secretion via cGMP in target enterocytes. Uroguanylin and ST also elicit diuretic and natriuretic responses in the kidney. GC-C is an intestinal receptor-GC for guanylin and uroguanylin, but GC-C may not be involved in renal cGMP pathways. A novel receptor-GC expressed in the opossum kidney (OK-GC) has been identified by molecular cloning. OK-GC cDNAs encode receptor-GCs in renal tubules that are activated by guanylins. Lymphoguanylin is highly expressed in the kidney and heart where it may influence cGMP pathways. Guanylin and uroguanylin are highly expressed in intestinal mucosa to regulate intestinal salt and water transport via paracrine actions on GC-C. Uroguanylin and guanylin are also secreted from intestinal mucosa into plasma where uroguanylin serves as an intestinal natriuretic hormone to influence body Na+ homeostasis by endocrine mechanisms. Thus, guanylin peptides control salt and water transport in the kidney and intestine mediated by cGMP via membrane receptors with intrinsic guanylate cyclase activity.

Towards understanding the kallikrein-kinin system: insights from measurement of kinin peptides

The kallikrein-kinin system is complex, with several bioactive peptides that are formed in many different compartments. Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning. We established a methodology for the measurement of individual kinin peptides in order to study the function of the kallikrein-kinin system. The levels of kinin peptides in tissues were higher than in blood, confirming the primary tissue localization of the kallikrein-kinin system. Moreover, the separate measurement of bradykinin and kallidin peptides in man demonstrated the differential regulation of the plasma and tissue kallikrein-kinin systems, respectively. Kinin peptide levels were increased in the heart of rats with myocardial infarction, in tissues of diabetic and spontaneously hypertensive rats, and in urine of patients with interstitial cystitis, suggesting a role for kinin peptides in the pathogenesis of these conditions. By contrast, blood levels of kallidin, but not bradykinin, peptides were suppressed in patients with severe cardiac failure, suggesting that the activity of the tissue kallikrein-kinin system may be suppressed in this condition. Both angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) inhibitors increased bradykinin peptide levels. ACE and NEP inhibitors had different effects on kinin peptide levels in blood, urine, and tissues, which may be accounted for by the differential contributions of ACE and NEP to kinin peptide metabolism in the multiple compartments in which kinin peptide generation occurs. Measurement of the levels of individual kinin peptides has given important information about the operation of the kallikrein-kinin system and its role in physiology and disease states.

Production, isolation and characterization of bioactive peptides with antihypertensive properties from rapeseed and potato protein

Consumers’ increasing awareness of healthiness and sustainability of food presents a great challenge to food industry to develop healthier, biologically active and sustainable food products. Bioactive peptides derived from food proteins are known to possess various biological activities. Among the activities, the most widely studied are antioxidant activities and angiotensin I converting enzyme (ACE) inhibitory activity related to blood pressure regulation and antihypertensive effects. Meanwhile, vast amounts of byproducts with high protein content are produced in food industry, for example potato and rapeseed industries. The utilization of these by-products could be enhanced by using them as a raw material for bioactive peptides. The objective of the present study was to investigate the production of bioactive peptides with ACE inhibitory and antioxidant properties from rapeseed and potato proteins. Enzymatic hydrolysis and fermentation were utilized for peptide production, ultrafiltration and solid-phase extraction were used to concentrate the active peptides, the peptides were fractionated with liquid chromatographic processes, and the peptides with the highest ACE inhibitory capacities were putified and analyzed with Maldi-Tof/Tof to identify the active peptide sequences. The bioavailability of the ACE inhibitory peptides was elucidated with an in vitro digestion model and the antihypertensive effects in vivo of rapeseed peptide concentrates were investigated with a preventive premise in 2K1C rats. The results showed that rapeseed and potato proteins are rich sources of ACE inhibitory and antioxidant peptides. Enzymatic hydrolysis released the peptides effectively whereas fermentation produced lower activities.The native enzymes of potato were also able to release ACE inhibitory peptides from potato proteins without the addition of exogenous enzymes. The rapeseed peptide concentrate was capable of preventing the development of hypertension in vivo in 2K1C rats, but the quality of rapeseed meal used as raw material was found to affect considerably the antihypertensive effects and the composition of the peptide fraction.

Role of sensory nervous system vasoactive peptides in hypertension

The goal of the present research was to elucidate the roles and mechanisms by which the sensory nervous system, through the actions of potent vasodilator neuropeptides, regulates cardiovascular function in both the normal state and in the pathophysiology of hypertension. The animal models of acquired hypertension studied were deoxycorticosterone-salt (DOC-salt), subtotal nephrectomy-salt (SN-salt), and Nomega-nitro-L-arginine methyl ester (L-NAME)-induced hypertension during pregnancy in rats. The genetic model was the spontaneously hypertensive rat (SHR). Calcitonin gene-related peptide (CGRP) and substance P (SP) are potent vasodilating neuropeptides. In the acquired models of hypertension, CGRP and SP play compensatory roles to buffer the blood pressure (BP) increase. Their synthesis and release are increased in the DOC-salt model but not in the SN-salt model. This suggests that the mechanism by which both models lower BP in SN-salt rats is by increased vascular sensitivity. CGRP functions in a similar manner in the L-NAME model. In the SHR, synthesis of CGRP and SP is decreased. This could contribute to the BP elevation in this model. The CGRP gene knockout mouse has increased baseline mean arterial pressure. The long-term synthesis and release of CGRP is increased by nerve growth factor, bradykinin, and prostaglandins and is decreased by alpha2-adrenoreceptor agonists and glucocorticoids. In several animal models, sensory nervous system vasoactive peptides play a role in chronic BP elevation. In the acquired models, they play a compensatory role. In the genetic model, their decreased levels may contribute to the elevated BP. The roles of CGRP and SP in human hypertension are yet to be clarified.

Imidazoline receptors in the heart: a novel target and a novel mechanism of action that involves atrial natriuretic peptides

Chronic stimulation of sympathetic nervous activity contributes to the development and maintenance of hypertension, leading to left ventricular hypertrophy (LVH), arrhythmias and cardiac death. Moxonidine, an imidazoline antihypertensive compound that preferentially activates imidazoline receptors in brainstem rostroventrolateral medulla, suppresses sympathetic activation and reverses LVH. We have identified imidazoline receptors in the heart atria and ventricles, and shown that atrial I1-receptors are up-regulated in spontaneously hypertensive rats (SHR), and ventricular I1-receptors are up-regulated in hamster and human heart failure. Furthermore, cardiac I1-receptor binding decreased after chronic in vivo exposure to moxonidine. These studies implied that cardiac I1-receptors are involved in cardiovascular regulation. The presence of I1-receptors in the heart, the primary site of production of natriuretic peptides, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), cardiac hormones implicated in blood pressure control and cardioprotection, led us to propose that ANP may be involved in the actions of moxonidine. In fact, acute iv administration of moxonidine (50 to 150 µg/rat) dose-dependently decreased blood pressure, stimulated diuresis and natriuresis and increased plasma ANP and its second messenger, cGMP. Chronic SHR treatment with moxonidine (0, 60 and 120 µg kg-1 h-1, sc for 4 weeks) dose-dependently decreased blood pressure, resulted in reversal of LVH and decreased ventricular interleukin 1ß concentration after 4 weeks of treatment. These effects were associated with a further increase in already elevated ANP and BNP synthesis and release (after 1 week), and normalization by 4 weeks. In conclusion, cardiac imidazoline receptors and natriuretic peptides may be involved in the acute and chronic effects of moxonidine.

Potential for synthetic gas in Finnish industry

Finland, other Nordic countries and European Union aim to decarbonize their energy production by 2050. Decarbonization requires large scale implementation of non-emission energy sources, i.e. renewable energy and nuclear power. Stochastic renewable energy sources present a challenge to balance the supply and demand for energy. Energy storages, non-emissions fuels in mobility and industrial processes are required whenever electrification is not possible. Neo-Carbon project studies the decarbonizing the energy production and the role of synthetic gas in it. This thesis studies the industrial processes in steel production, oil refining, cement manufacturing and glass manufacturing, where natural gas is already used or fuel switch to SNG is possible. The technical potential for fuel switching is assessed, and economic potential is necessary after this. All studied processes have potential for fuel switching, but total decarbonization of steel production, oil refining requires implementation of other zero-emission technologies.

Antibodies to citrullinated peptides are not associated with the rate of joint destruction in patients with a well-established diagnosis of rheumatoid arthritis

Antibodies to citrullinated peptides are highly specific for rheumatoid arthritis (RA) and represent a significant risk factor for undifferentiated polyarthritis. This prognostic ability may be related to the very diagnostic performance of these autoantibodies, since RA is a more erosive disease than other forms of arthritis. The present study evaluated an association of antibodies to citrullinated peptides and the rate of joint destruction in patients with a well-established diagnosis of RA. Seventy-one patients with RA were evaluated in 1994 and again in 2002 (functional class, joint count, Health Assessment Questionnaire score, hands X-ray). Autoantibodies (rheumatoid factor (RF), anti-perinuclear factor, anti-cyclic citrullinated peptide (CCP) antibodies) and Sharp's index were analyzed blindly. Delta Sharp was calculated as the difference in Sharp's index obtained in 1994 and 2002. During the follow-up the Health Assessment Questionnaire score increased from 0.91 ± 0.74 to 1.39 ± 0.72 (P < 0.001). Similarly, the number of swollen joints increased from 4.6 ± 5.71 to 6.4 ± 4.1 (P = 0.002). The frequency of autoantibodies and anti-CCP titer remained stable; however, serum RF concentration increased from 202.8 ± 357.6 to 416.6 ± 636.5 IU/mL (P = 0.003). Sharp's index increased from 56.7 ± 62.1 to 92.4 ± 80.9 (P < 0.001). No correlation was observed between Delta Sharp and the presence of RF, anti-perinuclear factor, and anti-CCP antibodies at baseline. Antibodies to citrullinated epitopes are specific and early markers for the diagnosis of RA but do not seem to be associated with the rate of joint destruction in patients with a well-established diagnosis of RA.

Antimicrobial peptides and nitric oxide production by neutrophils from periodontitis subjects

Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopolysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS (Ec-LPS). qRT-PCR was used to determine quantities of HNP 1-3 and LL-37 mRNA in neutrophils. Amounts of HNP 1-3 and LL-37 proteins in the cell culture supernatants were also determined by ELISA. In addition, NO levels in neutrophil culture supernatants were quantitated by the Griess reaction. Neutrophils from periodontitis patients cultured with Aa-LPS, Pg-LPS and Ec-LPS expressed higher HNP 1-3 mRNA than neutrophils from healthy subjects. LL-37 mRNA expression was higher in neutrophils from patients stimulated with Aa-LPS. Neutrophils from periodontitis patients produced significantly higher LL-37 protein levels than neutrophils from healthy subjects when stimulated with Pg-LPS and Ec-LPS, but no difference was observed in HNP 1-3 production. Neutrophils from periodontitis patients cultured or not with Pg-LPS and Ec-LPS produced significantly lower NO levels than neutrophils from healthy subjects. The significant differences in the production of LL-37 and NO between neutrophils from healthy and periodontitis subjects indicate that production of these molecules might influence individual susceptibility to important periodontal pathogens.

Effect of JJYMD-C, a novel synthetic derivative of gallic acid, on proliferation and phenotype maintenance in rabbit articular chondrocytes in vitro

Tissue engineering encapsulated cells such as chondrocytes in the carrier matrix have been widely used to repair cartilage defects. However, chondrocyte phenotype is easily lost when chondrocytes are expanded in vitro by a process defined as “dedifferentiation”. To ensure successful therapy, an effective pro-chondrogenic agent is necessary to overcome the obstacle of limited cell numbers in the restoration process, and dedifferentiation is a prerequisite. Gallic acid (GA) has been used in the treatment of arthritis, but its biocompatibility is inferior to that of other compounds. In this study, we modified GA by incorporating sulfamonomethoxine sodium and synthesized a sulfonamido-based gallate, JJYMD-C, and evaluated its effect on chondrocyte metabolism. Our results showed that JJYMD-C could effectively increase the levels of the collagen II, Sox9, and aggrecan genes, promote chondrocyte growth, and enhance secretion and synthesis of cartilage extracellular matrix. On the other hand, expression of the collagen I gene was effectively down-regulated, demonstrating inhibition of chondrocyte dedifferentiation by JJYMD-C. Hypertrophy, as a characteristic of chondrocyte ossification, was undetectable in the JJYMD-C groups. We used JJYMD-C at doses of 0.125, 0.25, and 0.5 µg/mL, and the strongest response was observed with 0.25 µg/mL. This study provides a basis for further studies on a novel agent in the treatment of articular cartilage defects.

The adherence of Pseudomonas fluorescens to marble, granite, synthetic polymers, and stainless steel

The adherence of Pseudomonas fluorescens cells to nine food-processing contact surfaces was evaluated using the plate-count method. The surfaces include marble, granite, stainless steel, polyvinyl chloride, polyurethane, and silicone-coated cloth, which have been used only in a few studies concerning bacterial adherence. The number of cells adhered to the surfaces increased with contact time reaching 5.0-6.1 log CDM.cm-2 after 10 hours, which can be considered a well established adherence process. The number of adhered cells doubled in 29.5 minutes and 23.5 minutes on stainless steel and thin polyvinyl chloride-coated cloth, respectively. For the other surfaces, this value was 9.8 minutes on average. Marble, granite, thick polyvinyl-coated cloth, double-faced rugous polyurethane, and silicone-coated cloth were not different (p < 0.05) in their ability to adhere cells (CFU/cm²) after 2 and 10 hours. The surfaces that had higher percentage of similarity in the adhesion level and higher log CFU/cm² of adhered cells were double-faced rugous polyurethane, silicone-coated cloth, and granite. The surfaces showed very different microtopography characteristics when viewed using scanning electron microscopy. This experiment showed the importance of using appropriate materials for food contact during processing, which will affect the cleaning and sanitation procedures.