54 research outputs found
Open FRW model in Loop Quantum Cosmology
Open FRW model in Loop Quantum Cosmology is under consideration. The left and
right invariant vector fields and holonomies along them are studied. It is
shown that in the hyperbolic geometry of it is possible to construct a
suitable loop which provides us with quantum scalar constraint originally
introduced by Vandersloot. The quantum scalar constraint operator with negative
cosmological constant is proved to be essentially self-adjoint.Comment: 12 pages, no figures, late
Effect of exogenously added rhamnolipids on citric acid production yield
The influence of a biosurfactant (rhamnolipids) on the effectiveness of citric acid production by Yarrowia lipolytica from sunflower oil was studied. The surfactant-mediated solubilization of the hydrophobic substrate was assessed by particle size distribution characteristics with and without the presence of sunflower oil hydrolization products. The presence of rhamnolipids contributed to a decrease of the oil droplet size, most notably for samples containing sunflower oil and its hydrolization products. The citric acid yield for cultures not supplemented with rhamnolipids was at 82.9 g/l, with a 1:0.04 citric acid to isocitric acid ratio (CA:ICA). The addition of rhamnolipids at 1 g/l resulted in a 5% increased citric acid yield (87.1 g/l), however a decrease (79.0 g/l) was observed for samples containing 5 g/l of rhamnolipids. The rhamnolipids-induced emulsification of sunflower oil did not seem to influence the citric acid production efficiency. Additional research revealed that the biosurfactant was degraded by yeast cells during the bioconversion process. The possible explanations of this phenomenon include the utilization of rhamnolipids as an alternative carbon source or microbial destabilization of micelles formed by this biosurfactant due to potential bioavailability issues.Keywords: Yarrowia lipolytica, citric acid, rhamnolipids, sunflower oilAfrican Journal of Biotechnology Vol. 12(21), pp. 3313-332
Evaluating robustness of a diesel-degrading bacterial consortium isolated from contaminated soil
Zespół Cushinga w przebiegu ektopowego wydzielania ACTH
Cushing’s syndrome (CS) is defined as a constellation of clinical signs and symptoms occurring due to hypercortisolism. Cortisol excess may be endogenous or exogenous. The most common cause of CS is glucocorticoid therapy with supraphysiological (higher than in the case of substitution) doses used in various diseases (e.g. autoimmune). One possible CS cause is ectopic (extra-pituitary) ACTH secretion (EAS) by benign or malignant tumours. Since its first description in 1963, EAS aetiology has changed, i.e. as well as small cell lung cancer (SCLC), higher incidence in other malignancies has been reported. Ectopic ACTH secretion symptoms are usually similar to hypercortisolism symptoms due to other causes. A clinical suspicion of CS requires laboratory investigations. There is no single and specific laboratory test for making a CS diagnosis, and therefore multiple dynamic tests should be ordered. A combination of multiple laboratory noninvasive and invasive tests gives 100% sensitivity and 98% specificity for EAS diagnosis. If the EAS is caused by localised malignancy, surgery is the optimal treatment choice. Radical tumour excision may be performed in 40% of patients, and 80% of them are cured of the disease. The authors present an interesting clinical case of EAS, which is always a huge diagnostic challenge for clinicians. (Endokrynol Pol 2016; 67 (4): 458–464)
Zespół objawów klinicznych: podmiotowych i przedmiotowych, które wynikają z hiperkortyzolemii określa się mianem zespołu Cushinga (CS). Nadmiar kortyzolu w organizmie może mieć źródło egzo- lub endogenne. Powszechnie uważa się, że najczęstszą przyczyną CS jest terapia glikokortykosteroidem w dawkach farmakologicznych, większych niż substytucyjne, z powodu różnych chorób, na przykład tkanki łącznej. Jedną z możliwych przyczyn CS jest ektopowe, czyli poza przysadkowe wydzielanie ACTH, przez nowotwór łagodny lub złośliwy. Od czasu pierwszego opisu w 1963 roku, etiologia ektopowego wydzielania ACTH uległa istotnej zmianie, poza drobnokomórkowym rakiem płuca (SCLC) opisano inne nowotwory, których częstość znacząco wzrosła. Symptomatologia CS w przebiegu ektopowego wydzielania ACTH najczęściej odpowiada objawom hiperkortyzolemii spotykanym u chorych z powodu innej przyczyny. Podejrzenie kliniczne CS wymaga weryfikacji laboratoryjnej. Nie ma swoistego, pojedynczego badania, które by potwierdziło CS w przebiegu ektopowego wydzielania ACTH, z tego względu należy posiłkować się szeregiem testów. Połączenie wielu badań laboratoryjnych, w tym inwazyjnych, sprawia, że czułość rozpoznania ektopowego wydzielania ACTH sięgnąć może 100%, przy swoistości 98%. W przypadku lokalizacji ogniska pierwotnego leczenie operacyjne jest postępowaniem optymalnym. Radykalne leczenie można zastosować u 40% chorych, z czego około 80% udaje się wyleczyć. Przedstawiony przypadek ektopowego wydzielania ACTH stanowi przykład licznych trudności diagnostycznych dla lekarza praktyka. (Endokrynol Pol 2016; 67 (4): 458–464)
Loop Quantum Cosmology corrections to inflationary models
In the recent years the quantization methods of Loop Quantum Gravity have
been successfully applied to the homogeneous and isotropic
Friedmann-Robertson-Walker space-times. The resulting theory, called Loop
Quantum Cosmology (LQC), resolves the Big Bang singularity by replacing it with
the Big Bounce. We argue that LQC generates also certain corrections to field
theoretical inflationary scenarios. These corrections imply that in the LQC the
effective sonic horizon becomes infinite at some point after the bounce and
that the scale of the inflationary potential implied by the COBE normalisation
increases. The evolution of scalar fields immediately after the Bounce becomes
modified in an interesting way. We point out that one can use COBE
normalisation to establish an upper bound on the quantum of length of LQG.Comment: 16 pages, 1 figure, plain Late
The status of Quantum Geometry in the dynamical sector of Loop Quantum Cosmology
This letter is motivated by the recent papers by Dittrich and Thiemann and,
respectively, by Rovelli discussing the status of Quantum Geometry in the
dynamical sector of Loop Quantum Gravity. Since the papers consider model
examples, we also study the issue in the case of an example, namely on the Loop
Quantum Cosmology model of space-isotropic universe. We derive the
Rovelli-Thiemann-Ditrich partial observables corresponding to the quantum
geometry operators of LQC in both Hilbert spaces: the kinematical one and,
respectively, the physical Hilbert space of solutions to the quantum
constraints. We find, that Quantum Geometry can be used to characterize the
physical solutions, and the operators of quantum geometry preserve many of
their kinematical properties.Comment: Latex, 12 page
Closed FRW model in Loop Quantum Cosmology
The basic idea of the LQC applies to every spatially homogeneous cosmological
model, however only the spatially flat (so called ) case has been
understood in detail in the literature thus far. In the closed (so called: k=1)
case certain technical difficulties have been the obstacle that stopped the
development. In this work the difficulties are overcome, and a new LQC model of
the spatially closed, homogeneous, isotropic universe is constructed. The
topology of the spacelike section of the universe is assumed to be that of
SU(2) or SO(3). Surprisingly, according to the results achieved in this work,
the two cases can be distinguished from each other just by the local properties
of the quantum geometry of the universe. The quantum hamiltonian operator of
the gravitational field takes the form of a difference operator, where the
elementary step is the quantum of the 3-volume derived in the flat case by
Ashtekar, Pawlowski and Singh. The mathematical properties of the operator are
studied: it is essentially self-adjoint, bounded from above by 0, the 0 itself
is not an eigenvalue, the eigenvectors form a basis. An estimate on the
dimension of the spectral projection on any finite interval is provided.Comment: 19 pages, latex, no figures, high quality, nea
Biodiversity of soil bacteria exposed to sub-lethal concentrations of phosphonium-based ionic liquids: Effects of toxicity and biodegradation
Little is known about the effect of ionic liquids (ILs) on the structure of soil microbial communities and resulting biodiversity. Therefore, we studied the influence of six trihexyl(tetradecyl)phosphonium ILs (with either bromide or various organic anions) at sublethal concentrations on the structure of microbial community present in an urban park soil in 100-day microcosm experiments. The biodiversity decreased in all samples (Shannon's index decreased from 1.75 down to 0.74 and OTU's number decreased from 1399 down to 965) with the largest decrease observed in the microcosms spiked with ILs where biodegradation extent was higher than 80%. (i.e. [P66614][Br] and [P66614][2,4,4]). Despite this general decrease in biodiversity, which can be explained by ecotoxic effect of the ILs, the microbial community in the microcosms was enriched with Gram-negative hydrocarbon-degrading genera e.g. Sphingomonas. It is hypothesized that, in addition to toxicity, the observed decrease in biodiversity and change in the microbial community structure may be explained by the primary biodegradation of the ILs or their metabolites by the mentioned genera, which outcompeted other microorganisms unable to degrade ILs or their metabolites. Thus, the introduction of phosphonium-based ILs into soils at sub-lethal concentrations may result not only in a decrease in biodiversity due to toxic effects, but also in enrichment with ILs-degrading bacteria
Effectiveness of Pharmacological Hypertension Treatment by General Practitioners in Poland
Wstęp: Nadciśnienie tętnicze jest bardzo częstym schorzeniem w Polsce. Dotyczy ponad 40% dorosłych Polaków. Większość osób świadomych swojego nadciśnienia jest leczonych przez lekarzy pierwszego kontaktu. Celem pracy była ocena skuteczności farmakologicznego leczenia hipotensyjnego pacjentów z nadciśnieniem tętniczym przez lekarzy pierwszego kontaktu w Polsce.
Materiał i metody: Zbadano 15 838 pacjentów leczonych z powodu nadciśnienia tętniczego przez 528 lekarzy pierwszego kontaktu. Każdemu pacjentowi dwukrotnie zmierzono ciśnienie tętnicze w odstępie około 5 min w pozycji siedzącej. Pomiaru dokonywali lekarze pierwszego kontaktu w gabinetach lekarskich. Dalszej analizie poddano wartości średnie z obu pomiarów.
Wyniki: Jedynie u 8,3% pacjentów leczonych (odpowiednio u 8,7% mężczyzn i u 7,9% kobiet) z powodu nadciśnienia stwierdzono ciśnienie tętnicze skurczowe SBP < 140 mm Hg i ciśnienie rozkurczowe
DBP < 90 mm Hg (różnica nieistotna statystycznie, p = 0,08). U kobiet 60-letnich i starszych skuteczność terapii hipotensyjnej była jednak istotnie niższa niż
u mężczyzn w tym samym wieku (odpowiednio 7,5% u kobiet oraz 9% u mężczyzn, p < 0,02). Natomiast
u mężczyzn 50-letnich i starszych skuteczność terapii hipotensyjnej była istotnie wyższa w porównaniu
z młodszymi mężczyznami (p < 0,001). Izolowane nadciśnienie skurczowe, definiowane jako SBP ł 140 i DBP < 90, występowało istotnie częściej u kobiet (16,7%) niż u mężczyzn (15,3%), (p < 0,01). Średnie ciśnienie skurczowe wynosiło 162,6 ± 20,7 mm Hg
u leczonych hipotensyjnie kobiet i 161,0 ± 19,9 mm Hg u mężczyzn (p < 0,001). Nie wykazano istotnych różnic między wartościami średniego DBP u kobiet
(94,8 ± 11,5 mm Hg) i mężczyzn (95,1 ± 11,4 mm Hg), (p = 0,37). Średnie ciśnienie tętna (PP) było istotnie wyższe u kobiet (67,8 ± 16,6 mm Hg) niż u mężczyzn (65,9 ± 16,0 mm Hg), (p < 0,001).
Wniosek: Wydaje się, że znaczna większość pacjentów z nadciśnieniem tętniczym leczonych hipotensyjnie przez lekarzy pierwszego kontaktu w Polsce jest leczona nieskutecznie. Ogólnie w całej badanej grupie nie ma istotnej różnicy skuteczności terapii hipotensyjnej między mężczyznami i kobietami.Background: Arterial hypertension is very common in Poland. Majority of subjects who are aware of the disease are treated by general practitioners (GPs). The aim of our study was to evaluate the treatment effectiveness in hypertensive patients treated by GPs in Poland.
Material and Methods: 15 838 hypertensive patients treated by 528 GPs from different parts of Poland were investigated. Every patient had his or her blood pressure measured twice within approximately 5-minute interval in sited position. We used mean blood pressure from both measurements in our further analysis. GPs performed blood pressure measurements in their cabinets.
Results: Only 8,3% treated hypertensive patients had systolic blood pressure SBP < 140 mmHg and diastolic blood pressure DBP < 90 mm Hg, 8,7% in men and 7,9%
in women respectively. In the whole cohort sex had no significant influence on hypertension therapy effectiveness (p = 0,08). However, in women aged 60 years or older the treatment efficacy turned out to be significantly lower compared to men of the same age (7,5% in women and 9% in men, p < 0,02). In addition, in men aged
50 years or older the treatment efficacy was significantly higher compared to younger men (p < 0,0001). The prevalence of isolated systolic hypertension defined as SBP ł ł 140 and DBP < 90 mm Hg was significantly more frequent in women. There was significant difference between mean SBP in men (161,0 ± 19,9 mm Hg) and women (162,6 ± 20,7 mm Hg, p < 0,001). Mean
DBP in women (94,8 ± 11,5 mm Hg) and men (95,1 ± ± 1,4 mm Hg) did not differ significantly (p = 0,37). The difference between mean pulse pressure (PP) in women (67,8 ± 16,6 mm Hg) and men (65,9 ± 16,0 mm Hg) was significant (p < 0,001).
Conclusion: It seems that vast majority of hypertensive patients treated pharmacologically by GPs in Poland is treated unsuccessfully. The situation is found to be relatively equally unsatisfactory in both men and women
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