Genus one factors of curves defined by separated variable polynomials

We give some sufficient conditions on complex polynomials P and Q to assure that the algebraic plane curve P(x)-Q(y)=0 has no irreducible component of genus 0 or 1. Moreover, if deg (P)=deg (Q) and if both P, Q satisfy Hypothesis I introduced by H. Fujimoto, our sufficient conditions are necessary

The role of toll-like receptors in the adrenal gland

Sepsis is caused by infection and often followed by an overwhelming inflammatory response. This can lead to shock, organ failure and even death. Each year approximately 60,000 people die in Germany due to sepsis. There is good evidence that sepsis is associated with failure of the hypothalamic-pituitary-adrenal-axis. In patients with sepsis, glucocorticoids (e.g. corticosterone, cortisol) released from adrenal glands play an essential role in preventing an excessive pro-inflammatory response. Adrenal insufficiency occurs in a large number of patients with septic shock and is associated with an increased mortality. In the innate immune system, Toll-like receptors (TLRs) play a crucial role in its onset by recognizing pathogenassociated molecules. It is well known that there are interactions between the immune and endocrine stress systems; glucocorticoids and TLRs regulate each other in a bi-directional way. Therefore, a coordinated response of the adrenal and immune system is of vital importance for survival during severe inflammation. This experimental study focuses on the role of TLR-2, TLR-4 and TLR-9 during adrenal stress. The results show that in mice, the absence of TLR-2 and TLR-4, but not TLR-9 leads to altered adrenal morphology, relating to size and cellular structure. However, this alteration does not appear to compromise the phenotype of TLR knock-out mice. Mice deficient of TLR-2, 4 and 9 are not able to respond adequately to inflammatory stress induced by their potential ligands lipopolysaccharide (LPS), lipoteichoic acid (LTA) or cytidine phosphate guanosine-oligodeoxynucleotides (CpG-ODN). This impaired adrenal stress response appears to be associated with a decrease in systemic and intra-adrenal cytokine expressions. Taken together, these results suggest that TLR-2, 4 and 9 are key players in the immuno-endocrine response during inflammation and SIRS. In conclusion, TLRs play a crucial role in the immune-adrenal crosstalk. This close functional relationship needs to be considered in the treatment of inflammatory diseases where an intact adrenal stress response is required. Furthermore, TLR polymorphisms could contribute to the underlying mechanisms of impaired adrenal stress response in patients with bacterial sepsisSepsis entsteht durch eine Infektion, der oft eine unkontrollierte Entzündungsreaktion folgt und die letztendlich in Schock, Organversagen oder Tod münden kann. Jedes Jahr sterben allein in Deutschland bis zu 60.000 Menschen an einer Sepsis. Vieles weist darauf hin, dass die Sepsis in Zusammenhang mit dem Versagen der Hypothalamus-Hypophysen-Nebennierenrinden-Achse steht. Es ist bekannt, dass bei septischen Patienten die von den Nebennieren freigesetzten Glukokortikoide (Kortisol, Kortikosteron) eine wesentliche Rolle während der Unterdrückung einer exzessiven proinflammatorischen Reaktion spielen. Die Nebenniereninsuffizienz tritt in großer Anzahl bei Patienten im septischen Schock auf und ist verantwortlich für die erhöhte Sterblichkeit der an Sepsis Erkrankten. Im Rahmen des angeborenen Immunsystems spielen die sogenannten Toll-like Rezeptoren (TLRs) eine bedeutende Rolle bei der Erkennung von pathogen-assoziierten Molekülen. Interaktionen zwischen dem Immunsystem und dem endokrinen Stresssystem sind bekannt. Demzufolge ist eine gut aufeinander abgestimmte Antwort des adrenalen Systems und des Immunsystems für das Überleben während einer schweren Entzündungsreaktion von besonderer Bedeutung. Die vorliegende Arbeit befasst sich mit der Rolle von TLR-2, TLR-4 und TLR-9 während adrenalem Stress. Die Ergebnisse zeigen, dass das Fehlen von TLR-2 oder TLR-4, aber nicht TLR-9 zur Änderung der Morphologie der Nebennieren, bezüglich ihrer Größe und zellulären Struktur, bei den Mäusen führt. Dennoch scheint diese Änderung den Phänotyp der TLR knock-out Mäuse nicht zu beeinträchtigen. Mäuse mit fehlendem TLR-2, 4 oder 9 sind unfähig, sich adäquat auf einen inflammatorischen Stress, der durch die entsprechenden Liganden Lipopolysaccharid (LPS, TLR-4), Lipoteichonsäure (LTA, TLR-2) oder Cytidin-Phosphat-Guanosin-Oligodeoxynucleotid (CpG-ODN, TLR-9) hervorgerufen wird, zu antworten. Diese verminderte adrenale Stressantwort scheint mit der Abschwächung der systemischen und auch der intra-adrenalen Zytokin-Expressionen einherzugehen. Zusammenfassend deuten diese Ergebnisse darauf hin, dass TLR-2, 4 und 9 Schlüsselrezeptoren in der immun-adrenalen Antwort bei Entzündung und SIRS sind. Das enge funktionale Verhältnis zwischen den beiden Systemen sollte im Rahmen der Behandlung von entzündlichen Krankheiten, bei denen eine intakte adrenale Stressantwort erforderlich ist, berücksichtigt werden. Darüber hinaus könnten TLR Polymorphismen zu den zugrunde liegenden Mechanismen der beeinträchtigten adrenalen Stressantwort bei Patienten mit bakterieller Sepsis beigetragen haben

Synthesis and characterization of polyimide membrane for carbon dioxide removal prepared by dry-wet phase inversion method

Currently, membrane is a separation process that is gaining lots of attention in the industry, especially membranes for gas separation processes such as removal of carbon dioxide from natural gas. Among the available materials for these membranes, cellulose acetate has always been used as the conventional membrane polymer. In this paper, the focus was on polyimide, which was proposed to be the new alternative for cellulose acetate with certain distinguished advantages. As polyimide membrane is still a new material for membrane, this study focused on the detailed synthesis procedure of a flat sheet polyimide membrane through dry-wet phase inversion method. The chosen polymer was BTDA/ODA (Biphenyl Tetracarboxylic Dianhydride/ Oleoyl Diamine), along with DMF (Dimethyl Formamide) as solvent and a mixture of water/ethanol as non-solvents in coagulation bath. An addition of binder to the synthesis procedure was also tested in this paper. Characteristic tests were conducted to study about the morphology as well as the porosity of the membrane synthesis. In addition, some variations on membrane composition were conducted to study about the effect of polymer concentration, coagulation bath composition and binder addition on polyimide membrane. Lastly, a process optimization was done to choose the most suitable conditions and composition for the membrane synthesis

Collateral sensitivity in clinical mecillinam resistant isolates of Escherichia coli

Background The rapid increase in antimicrobial resistance (AMR) has become a major threat to the successful management of infectious diseases. To counteract this global threat, development of novel treatment strategies is essential. A promising strategy may be exploiting collateral sensitivity; a phenomenon that occurs when a microorganism that has developed resistance to one antimicrobial agent, exhibits increased susceptibility to another antimicrobial agent. In order to develop novel treatment strategies and prevent further resistance development, we aimed to explore the generality of the concept of collateral sensitivity in clinical urinary tract isolates of E. coli. Furthermore, we wanted to investigate the underlying mechanisms of collateral sensitivity. Methods We evolved resistance to mecillinam in a collection of clinical isolates of E. coli. Ten were selected for further determination of possible collateral sensitivity and cross-resistance networks. The IC90-assay with micro broth dilution was used for this purpose, which we tested for eight different antimicrobial agents. The results were displayed in heat maps and graphs showing the distribution of AMR to various agents. PCR and DNA sequencing were performed for the mrdA gene to detect mutations that may confer mecillinam resistance. Results According to our results both collateral sensitivity and cross-resistance occurred in mecillinam resistant isolates. Chloramphenicol presented the highest tendency of collateral sensitivity, while ciprofloxacin presented the highest tendency of cross-resistance. In general, a substantial tendency for collateral sensitivity frequently appeared compared to cross-resistance. Moreover, 13 synonymous point mutations were observed in the mrdA gene, leading to no alteration in the amino acid sequence. Conclusion Based on our in vitro results, we suggest mecillinam could be a good candidate to be employed as the first drug of choice for UTIs caused by E. coli. Mecillinam resistant isolates exhibited a clear tendency for collateral sensitivity, which we believe would occur on the population level as well. Further investigations of the underlying mechanisms of collateral sensitivity are required