bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of Cellulase Synthesis in Batch and Continuous Cultures of
Clostridium thermocellum
Authors: Yi-Heng Zhang Percival , Lynd Lee R. 
Published: December 2004

ABSTRACT

Regulation
of cell-specific cellulase synthesis (expressed in milligrams of
cellulase per gram [dry weight] of cells) by
Clostridium
thermocellum
was investigated using an enzyme-linked immunosorbent
assay protocol based on antibody raised against a peptide sequence from
the scaffoldin protein of the cellulosome (Zhang and Lynd, Anal. Chem.
75:
219-227, 2003). The cellulase synthesis in
Avicel-grown batch cultures was ninefold greater than that in
cellobiose-grown batch cultures. In substrate-limited continuous
cultures, however, the cellulase synthesis with Avicel-grown cultures
was 1.3- to 2.4-fold greater than that in cellobiose-grown cultures,
depending on the dilution rate. The differences between the cellulase
yields observed during carbon-limited growth on cellulose and the
cellulase yields observed during carbon-limited growth on cellobiose at
the same dilution rate suggest that hydrolysis products other than
cellobiose affect cellulase synthesis during growth on cellulose and/or
that the presence of insoluble cellulose triggers an increase in
cellulase synthesis. Continuous cellobiose-grown cultures maintained
either at high dilution rates or with a high feed substrate
concentration exhibited decreased cellulase synthesis; there was a
large (sevenfold) decrease between 0 and 0.2 g of cellobiose
per liter, and there was a much more gradual further decrease for
cellobiose concentrations >0.2 g/liter. Several factors suggest
that cellulase synthesis in
C. thermocellum
is regulated by
catabolite repression. These factors include: (i) substantially higher
cellulase yields observed during batch growth on Avicel than during
batch growth on cellobiose, (ii) a strong negative correlation between
the cellobiose concentration and the cellulase yield in continuous
cultures with varied dilution rates at a constant feed substrate
concentration and also with varied feed substrate concentrations at a
constant dilution rate, and (iii) the presence of sequences
corresponding to key elements of catabolite repression systems in the
C. thermocellum
genome.
A Pragmatic, Co-operative Approach To Teaching Environmental Ethics
Authors: Shapiro Daniel , Takacs David 
Published: December 2004

AbstractOur pragmatic, cooperative approach to teaching environmental ethics at California State University Monterey Bay nurtures students' moral development in both their public and private realms by putting into practice three principles. First, to propose what "we ought to do," students must first think deeply about what " I ought to do." Second, adequately justifying what "I ought to do" and what "we ought to do" requires that students acknowledge, understand, and respect differing perspectives. Third, a course that does not advocate for a particular environmental ethic enhances rather than inhibits students' moral development. This paper describes how—and why—we have designed our course in accordance to these three principles.
Balance of MafB and PU.1 specifies alternative macrophage or dendritic cell fate
Authors: Bakri Youssef , Sarrazin Sandrine , Mayer Ulrich P. , Tillmanns Silke , Nerlov Claus , Boned Annie , Sieweke Michael H. 
Published: December 2004

AbstractMacrophages and myeloid dendritic cells (DCs) represent alternative differentiation options of bone marrow progenitors and blood monocytes. This choice profoundly influences the immune response under normal and pathological conditions, but the underlying transcriptional events remain unresolved. Here, we show that experimental activation of the transcription factors PU.1 and MafB in transformed chicken myeloid progenitors triggered alternative DC or macrophage fate, respectively. PU.1 activation also was instructive for DC fate in the absence of cytokines in human HL-60 cell-derived myeloid progenitor and monocyte clones. Differentiation of normal human monocytes to DCs led to a rapid increase of PU.1 to high levels that preceded phenotypic changes, but no MafB expression, whereas monocyte-derived macrophages expressed MafB and only moderate levels of PU.1. DCs inducing levels of PU.1 inhibited MafB expression in monocytes, which appeared to be required for DC specification, since constitutive MafB expression inhibited DC differentiation. Consistent with this, PU.1 directly bound to MafB, inhibited its transcriptional activity in macrophages, and repressed its ability to induce macrophage differentiation in chicken myeloid progenitors. We propose that high PU.1 activity favors DCs at the expense of macrophage fate by inhibiting expression and activity of the macrophage factor MafB.
Inhibition of Nox-4 activity by plumbagin, a plant-derived bioactive naphthoquinone
Authors: Ding Yaxian , Chen Zi-Jiang , Liu Shiguo , Che Danian , Vetter Michael , Chang Chung-Ho 
Published: December 2004

AbstractNAD(P)H oxidase contributes to the pathogenesis of cancer and cardiovascular diseases such as hypertension, atherosclerosis, restenosis, cardiac hypertrophy and heart failure. Plumbagin, a plant-derived naphthoquinone, has been shown to exert anticarcinogenic and anti-atherosclerosis effects in animals. However, the molecular mechanisms underlying these effects remain unknown. It is possible that the beneficial effect of plumbagin is due to the inhibition of NAD(P)H oxidase. Human embryonic kidney 293 (HEK293) and brain tumour LN229 cells express mainly Nox-4, a renal NAD(P)H oxidase. We have examined the effect of plumbagin on Nox-4 activity in HEK293 and LN229 cells using lucigenin-dependent chemiluminescence assay. Plumbagin inhibited the activity of Nox-4 in a time- and dose-dependent manner in HEK293 and LN229 cells. Production of superoxide in HEK293 cells was inhibited by diphenyleneiodonium (DPI), a NAD(P)H oxidase inhibitor. The superoxide production in HEK293 cells was NADPH- and NADH-dependent indicating that the superoxide was generated by a NAD(P)H oxidase in HEK293 cells, but not by the redox-cycling of lucigenin. Furthermore, plumbagin inhibited the superoxide production in Nox-4 transfected COS-7 cells. These results indicated that plumbagin directly interacted with Nox-4 and inhibited its activity.
Antioxidant eugenosedin-A protects against lipopolysaccharide-induced hypotension, hyperglycaemia and cytokine immunoreactivity in rats and mice
Authors: Shen Kuo-Pyng , Lo Yi-Ching , Yang Rei-Cheng , Liu Hong-Wen , Chen Ing-Jun , Wu Bin-Nan 
Published: December 2004

Abstract
Eugenosedin-A has been demonstrated to possess α/β-adrenoceptor and serotonergic receptor blocking activities. We have investigated by what mechanisms eugenosedin-A prevents lipopolysaccharide (LPS)-induced hypotension, vascular hyporeactivity, hyperglycaemia, oxidative injury or inflammatory cytokines formation in rats. Intravenous administration of eugenosedin-A, trazodone, yohimbine (1 mg kg−1), aminoguanidine or ascorbic acid (15 mg kg−1) normalized LPS (10 mg kg−1)-induced hypotension. Pretreatment with eugenosedin-A or the other agents 30 min before LPS injection reduced aortic hyporeactivity. LPS-induced increases in plasma interleukin-1β (IL-β), IL-6, interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α) and blood glucose levels were significantly inhibited by eugenosedin-A (1 mg kg−1, i.v.). The same dose of trazodone, a chloropiperazinylbenzene-type antidepressant, and yohimbine, an α2-adrenoceptor antagonist, reduced IL-1β and TNF-α, but it could not inhibit hyperglycaemia. Aminoguanidine, an inducible nitric oxide synthase (iNOS) inhibitor, and ascorbic acid, an antioxidant, decreased IL-1β, TNF-α contents and hyperglycaemia. Eugenosedin-A and the other agents inhibited Fe2+-ascorbic acid-induced peroxidation in rat cortex, indicating that those agents had antioxidant effects, with the exception of aminoguanidine. In free radical scavenged experiments, eugenosedin-A and ascorbic acid eliminated peroxyl radicals. All test agents inhibited the LPS-induced increase of malondialdehyde (MDA) content in rat brain homogenates. When mice were administered an intraperitoneal injection of LPS alone, mortality occurred from 4 to 16 h, after which time all were dead. However, eugenosedin-A significantly prolonged the survival time after LPS injection, suggesting that eugenosedin-A protected against LPS-induced cardiovascular dysfunction, hyperglycaemia, tissue injury and inflammatory cytokine production. This was attributable mainly to the antioxidant and peroxyl radical scavenged effects of eugenosedin-A, and which may be, at least in part, due to its blockade on α/β-adrenergic and serotonergic receptors.
Chronic oral administration of Ocimum sanctum Linn. augments cardiac endogenous antioxidants and prevents isoproterenol-induced myocardial necrosis in rats
Authors: Sood S , Narang D , Dinda A K , Maulik S K 
Published: December 2004

Abstract
Wistar rats (200–250 g) of either sex were fed with fresh leaf homogenate of Ocimum sanctum by oral gavage in two different doses, 50 mg kg−1 (Os 50) and 100 mg kg−1 (Os 100), daily for 30 days. This was followed by isoproterenol administration (85 mg kg−1 s.c. two doses at 24 h intervals) in both control and O. sanctum-fed rats to induce myocardial necrosis. Hearts were isolated for estimation of endogenous myocardial antioxidants (superoxide dismutase (SOD), catalase, reduced glutathione (GSH) and glutathione peroxidase (GPx) and myocardial lipid peroxidation) and light microscopic study. Increased basal myocardial antioxidant SOD (9.3 ± 1.2 vs 3.7 ± 0.7 units mg−1 protein; P &lt; 0.05) and catalase activities (34.3 ± 5.4 vs 17.9 ± 5.1 units mg−1 protein; P &lt; 0.05) were observed in the Os 50 group only without any evidence of cellular injury in both the groups. In control rats, isoproterenol administration caused significant depletion of myocardial SOD (1.7 ± 0.2 units mg−1 protein) and GPx (104 ± 2 mU mg−1 protein) activities and increase in GSH (551.7 ± 30.9 μg g−1 wet weight of tissue) level, with evidence of myocardial necrosis. Isoproterenol-induced changes in myocardial SOD, GPx and GSH were prevented by both the doses of O. sanctum, however cellular injury was minimal only with 50 mg kg−1. The results indicate that long-term feeding of O. sanctum offered significant protection against isoproterenol-induced myocardial necrosis through a unique property of enhancement of endogenous antioxidants.
Does feeding limit cardiovascular modulation in the Dungeness crabCancer magisterduring hypoxia?
Authors: McGaw Iain J. 
Published: December 2004

SUMMARYDecapod crustaceans inhabit aquatic environments that are frequently subjected to changes in oxygen content. The physiological mechanisms that allow them to cope with periodic episodes of hypoxia have been well documented. Most crustaceans exhibit a bradycardia coupled with diversion of haemolymph from digestive organs towards ventral structures. However, all these experiments were conducted on animals that were starved prior to experimentation in order to avoid increases in metabolism associated with digestive processes. The present study sought to determine how the Dungeness crab Cancer magister balances the demands of physiological systems when they feed and digest in hypoxia. Cardiac parameters and haemolymph flow rates through each arterial system exiting the heart were measured using a pulsed-Doppler flowmeter. Scaphognathite beat frequency (ventilation rate) was calculated by recording changes in pressure in the branchial chamber. There was an increase in both cardiac and ventilatory parameters following feeding. Digestive processes were facilitated by an increase in haemolymph flow rates through the anterior aorta, hepatic arteries and sternal artery. Cancer magister showed a typical bradycardia during hypoxia (3.2 kPa). However,food intake caused a significant reduction in this response. Likewise,ventilation rate also showed effects of addivity, increasing in response to both food intake and hypoxia. Digestion during hypoxia was associated with a decrease in both stroke volume and cardiac output. Blood was diverted away from digestive structures, suggesting that blood flow events are prioritized during hypoxia. The changes in haemolymph flow rates paralleled those in previous reports on reductions in protein synthesis in the hepatopancreas during hypoxia. Haemolymph flow rates through the anterior aorta did not change; thus the blood supply to the supraoesophageal ganglion was maintained during feeding in hypoxia. The results show that the nutritional state of an animal is important in modulating its physiological responses to environmental perturbations. This underscores the importance of an integrative approach,studying physiological responses at the organismal level.
Navigation as a tool to visualize bone-covered hidden structures in transfrontal approaches
Authors: Schipper Joerg , Maier Wolfgang , Arapakis Iakovos , Spetzger Uwe , Laszig R. 
Published: December 2004

A retrospective analysis of 10 patients was performed to evaluate navigation systems in extranasal frontal skull base surgery. When performing a craniotomy following a bicoronal skin incision, the surgeon has to calculate the extent of the frontal sinus to avoid unnecessary damage to the dura or mucoceles later. Due to surgical morbidity including compression of the frontal lobe, many skull base surgeons have refused to use such an approach. Malformation or bone-destruction complicates the identification of the borders and increases the risk ofside-effects. Navigation systems can be an alternative for calculating the frontal sinus outlines during surgery. In the authors’ surgical procedure two different navigation systems were used. Conventional surgery using the transfrontal, transbasal or subcranial approach consisting of trepanation and craniotomy were performed, while the navigated surgical procedure was evaluated.The analysis showed that computer-assisted surgery (CAS) is applicable to extranasal frontalskull base surgery. In comparison to X-ray beam-controlled craniotomy, CAS is beneficial as it constitutes a noninvasive instrument of quality management. Furthermore, the analysis indicatedthat under the guidance of a navigation system a precise pre-surgical simulation is available in order to perform an optimal craniotomy and reconstruction of the frontal skull base.
Scope of International Hospital Pharmacy Practice
Authors: LeBlanc Jaclyn M , Dasta Joseph F 
Published: December 2004

OBJECTIVE: To review the published English literature regarding international hospital pharmacy practice. DATA SOURCES: A computer search of all English-language articles in MEDLINE (1966–June 2004) and other Internet sources and International Pharmaceutical Abstracts (1971–June 2004). STUDY SELECTION AND DATA EXTRACTION: All studies that discussed hospital pharmacy or clinical hospital pharmacy activities outside of the US were considered for inclusion. DATA SYNTHESIS: The scope of international hospital pharmacy practice is quite varied, both inter- and intra-country, and varying degrees of specialization exist. Although clinical pharmacy is well developed in some countries, it is still in infancy stages in others. In addition, there is disparity in the actual definition of clinical pharmacy throughout the world. CONCLUSIONS: Since very few data have been published regarding hospital pharmacy practice on an international scale, we suggest a survey be conducted to objectively capture this information and increase awareness of clinical pharmacy in this setting.
Rifaximin: A New Treatment for Travelers' Diarrhea
Authors: Pakyz Amy L 
Published: December 2004

OBJECTIVE: To review the pharmacology, pharmacokinetics, clinical efficacy, adverse effects, drug interactions and precautions, and dosing recommendations of rifaximin, a new nonabsorbed antimicrobial agent for travelers' diarrhea. DATA SOURCES: A MEDLINE search (1966–July 2004) was conducted to extract human and animal research data in the English language on rifaximin. STUDY SELECTION AND DATA EXTRACTION: Randomized, double-blind, placebo-controlled trials were reviewed and included to evaluate the efficacy of rifaximin in the treatment of travelers' diarrhea. DATA SYNTHESIS: Rifaximin is approved for the treatment of travelers' diarrhea in patients ≥12 years of age with diarrhea caused by noninvasive strains of Escherichia coli. Rifaximin was superior to placebo and trimethoprim/sulfamethoxazole and equivalent to ciprofloxacin in the primary clinical endpoint of the time to the last unformed stool passed. CONCLUSIONS: Rifaximin is a viable alternative to ciprofloxacin for the treatment of travelers' diarrhea. As rifaximin is not systemically absorbed, it offers the advantage of leading to the development of less resistance compared with systemically absorbed antibiotics, in addition to fewer systemic adverse effects and drug interactions. However, the potential for cross-resistance between rifaximin and rifampin, as well as with other classes of antibiotics, is of concern and needs to be elucidated.
The asymptotes of loop reactors
Authors: Sheintuch Moshe , Nekhamkina Olga 
Published: December 2004

AbstractLoop reactors extend the flow‐reversal concept to rotating port feeding in a loop‐shape system made of N units. To analyze its behavior two limiting models are derived for a system with an infinite number of units: The first one corresponds to an arbitrary switching velocity, whereas the second corresponds to large switching velocities and is essentially a cross‐flow model. Both models can admit, with a generic first‐order Arrhenius kinetics and typically large Pe and Le numbers, a rotating‐pulse solution with peak temperatures that significantly exceeds the increase in adiabatic temperature. Both solutions were corroborated by simulations of finite‐N systems that show convergence to the expected asymptotes in realistic system lengths. Rotating pulses emerge over a wide domain of parameters, when the ratio of switching velocity to front propagation velocity is properly tuned around unity, and in a relatively narrow domain of parameters, around the Hopf bifurcation to spatial oscillations, when that ratio is high. Between these two (slow‐ and fast‐switching) behaviors the system exhibits a complex structure of solutions. The asymptotic models enabled us to draw bifurcation diagrams and characterize the properties of emerging solutions. Future studies will apply the loop reactor concept to reversible reactions and endothermic–exothermic reactions. © 2004 American Institute of Chemical Engineers AIChE J, 51: 224–234, 2005
Bauliche Konzeptentwicklung für eine 3‐Liter‐Reihenhauszeile im Rahmen von Modernisierungsmaßnahmen in Mannheim‐Gartenstadt
Authors: Reiß Johann , Erhorn Hans 
Published: December 2004

AbstractIm Wohngebiet Mannheim‐Gartenstadt erfolgen in den Jahren 2001 bis 2008 umfangreiche Teilmodernisierungs‐, Vollmodernisierungs‐ und Abbruchmaßnahmen sowie anschließende Neubebauung. Insgesamt werden 10 zweigeschossige Wohnbauten mit rund 230 Wohnungen aus den 1930er und 1950er Jahren modernisiert. Die Wohnungen sind sanierungsbedürftig, da sie sowohl baulich als auch anlagentechnisch nicht mehr dem heutigen Standard entsprechen. Mit den baulichen Maßnahmen verfolgt die GBG ndash; Mannheimer Wohnungsbaugesellschaft auch das Ziel, die Attraktivität des Wohnquartiers zu steigern. Bis Ende 2003 ist der Abschluß der Modernisierung von 3 Gebäuden mit insgesamt 68 Wohnungen geplant. Bei der bisherigen Sanierung wurden lediglich die gesetzlichen Anforderungen der Energieeinsparverordnung (EnEV) erfüllt. Künftig wird bei einer Wohnzeile mit 6 Wohnhäusern ein weit über diese Anforderungen hinausgehendes energetisches Niveau angestrebt. Diese Gebäude sollen energetisch zu 3‐Liter‐Häusern ertüchtigt werden. Im Bereich des Wohnungsneubaus wurde dies schon erfolgreich umgesetzt. Beim Bauen im Bestand stellt es noch eine Herausforderung dar. Als 3‐Liter‐Häuser werden Niedrigenergiehäuser bezeichnet, die für die Beheizung (einschließlich Hilfsenergie) einen jährlichen Primärenergiebedarf von weniger als 34 kWh/m2a aufweisen. Dies entspricht dem Primärenergieinhalt von 3 Litern Heizöl.
Feuerstätten in Häusern mit mechanischen Lüftungsanlagen ndash; Anforderungen und Lösungen
Authors: Sprung Joachim 
Published: December 2004

AbstractFür raumluftunabhängige Feuerstätten für flüssige und feste Brennstoffe gibt es bauaufsichtliche Zulassungskriterien. Diese beziehen sich bei Festbrennstoff‐Feuerstätten auf höhere Dichtheitsanforderungen, geringere CO‐Emissionen und die Forderung nach einer selbstschließenden Tür. Bei kritischer Analyse der Zulassungskriterien ist festzustellen, daß die Grenzwerte von Leckagevolumenstrom und CO‐Emission einen Luftwechsel im Aufstellraum mittlerer Größe von über 1, 5 h‐1 bedingen. Diskontinuierlich beheizte Speicher‐Feuerstätten sind für solche Einsatzfälle vorteilhaft, weil Konzentrationsanreicherungen im Wohnraum außerhalb der Beheizungsphase der Feuerstätte durch die Lüftungsanlage abgebaut werden können. Besondere Aufmerksamkeit bedarf die Verbrennungsluftführung im nebeneinander liegenden und konzentrischen Luft‐Abgas‐System (LAS). Unter winterlichen Bedingungen entstehen außerhalb des Betriebs der Feuerstätte Zirkulationsströmungen, wenn der Strömungsweg Verbrennungsluftschacht‐Feuerstätte‐Abgasschacht nicht durch Absperreinrichtungen unterbrochen wird. Die Folgen sind Taupunktunterschreitungen, Feuchtebildung mit Vereisungserscheinungen im unbeheizten Unterdachbereich, aber auch an der Dach‐ und Deckendurchdringung in diesem Bereich. Hinsichtlich der Dichtheitsprüfung installierter Anlagen und deren Überwachung stehen Anforderungen und Lösungen aus.
Rechnerische Methoden zur Erfassung von Wärmebrücken im Hinblick auf einen möglichen Schimmelpilzbefall
Authors: Cziesielski Erich , Belaschk Hendrik 
Published: December 2004

AbstractSchimmelpilzschäden stellen häufig zu beurteilende Schadensfälle dar. Die dabei im Rahmen von Gerichtsgutachten zu bearbeitende Problematik ist komplex. Unter anderem ist es erforderlich, vorhandene Konstruktionen rechnerisch auf eine mögliche Schimmelpilzbildung hin zu untersuchen. Die Berechnungsmethoden zur Beurteilung von Schimmelpilzbildung werden vorgestellt: das stationäre Berechnungsverfahren nach DIN 4108, das biohygrothermische Verfahren nach Sedlbauer und das instationäre Verfahren. Darüber hinaus wird der Einfluß einer fehlerhaft ausgeführten thermischen Entkoppelung im Bereich eines auskragenden Flachdaches auf die minimale Wandoberflächentemperatur nach stationären und instationären Berechnungsverfahren aufgezeigt.
Innovative Lehr‐ und Lernmethoden in der bauphysikalischen Ausbildung
Authors: Mehra Schew‐Ram , Sedlbauer Klaus 
Published: December 2004

AbstractNeue Medien und Techniken bieten Möglichkeiten, durch die das Lehren und Lernen andere Dimensionen und Formen annimmt. Gerade Bauphysik bietet ideale Voraussetzungen dafür. Im Rahmen des “multimedialen Lernnetzes Bauphysik” wurden innovative Methoden für die bauphysikalische Lehre entwickelt und erprobt. Damit soll den Studierenden ergänzend zu der traditionellen Präsenzlehre ein zeit‐ und ortsunabhängiges Selbststudium ermöglicht werden. Um auch die Ausbildung in der bauphysikalischen Meßtechnik zu ermöglichen, wurde das virtuelle Labor “SonicLab” entwickelt, mit dem akustische Messungen durchgeführt werden können. Es erlaubt den Studierenden, sich mit den Prüfräumen, Meßgeräten und dem Ablauf der Messungen vertraut zu machen. Ingenieure und vor allem Handwerker sind oftmals mit neuen bauphysikalischen Fragestellungen konfrontiert. Als Möglichkeit ihrer Schulung wurde in Zusammenarbeit mit der Handwerkskammer Münster ein Kompetenz‐ und Demonstrationszentrum für energiesparendes und ökologisches Bauen erstellt. Dort werden Weiterbildungsseminare mit Zuhilfenahme von Online‐Messungen im Gebäude und Lern‐ und Lehrsoftwaretools durchgeführt.