184 research outputs found
Efficacy of atovaquone combined with clindamycin against murine infection with a cystogenic (Me49) strain of Toxoplasma gondii
The efficacy of atovaquone (ATO) combined with clindamycin (CLI) against Toxoplasma gondii was examined in murine models of infection with a mouse-non-virulent (Me49) strain. Swiss-Webster mice inoculated by mouth with 10 or 20 cysts were treated with ATO and CLI alone or combined at dosages of ATO 5-100 and CLI 25-400 mg/kg/day for 2-4 weeks. Drug treatment was initiated (i) day 4 post-infection (acute infection), (ii) 3 months post-infection (chronic infection) and (iii) following a 2-3 week course of treatment with dexamethasone (DXM) alone or combined with cortisone-acetate (CA) introduced 3 months post-infection (reactivated toxoplasmosis). In acute infection, whereas treatment with any drug or drug combination significantly enhanced survival and reduced the brain cyst burden, in mice treated with ATO alone or combined with CLI, the cyst counts were significantly lower than in mice treated with CLI alone. In chronic infection, the decrease in the cyst burden observed 2 weeks after treatment with either drug alone was significant only in mice treated with the combined drugs. Most importantly, in reactivated toxoplasmosis, whereas an effect for the combined drugs was shown in mice suppressed with both DXM alone and combined with CA, in mice pre-treated with DXM a 3 week course of ATO greater than or equal to25 and CLI 50 mg/kg/day significantly increased survival and markedly decreased the cyst burden. The latter effect was long-term, since the cyst burdens in treated mice continued to decrease up to 3 months later, whereas they increased in the untreated mice. The results warrant clinical evaluation of the combination of ATO and CLI in the treatment of toxoplasmosis in both immunocompetent and, more importantly, immunosuppressed patients
ELECTRONS OR PROTONS: WHAT IS THE CAUSE OF FOREST FIRES IN WESTERN EUROPE ON JUNE 18, 2017?
Forest fires in Portugal (June 17–24, 2017) destroyed 64 lives and caused considerable material damage. The coronal hole CH807 and the energy region S5710 were in the geoeffective position on the Sun immediately before the outbreak of fires. In the period that preceded it, as well as at the time of the fires, increased values of the solar wind (SW) parameters (temperature, speed and density of particles) were recorded. In addition, a geomagnetic disorder was recorded. The shape and size of the burning areas, as well as the low air pressure over Portugal indicate the possibility of the effect of positively charged particles that came from the area south, i.e. southwest of Portugal. Nevertheless, it is a specific case that would have to be investigated in more detail
Positive effects of naringenin on near-surface membrane fluidity in human erythrocytes
Purpose: Deformability/rheologic behavior of erythrocytes are related to near-surface membrane fluidity. Specific agents can increase erythrocyte membrane fluidity in order to adjust hemodynamics in cardiovascular diseases. Grapefruit flavanone naringenin has been proposed for potential use in an alternative therapy of cardiovascular conditions. In respect to this, we assessed here effects of two nutritionally relevant concentrations of naringenin (0.1 and 1 μg/ml) on near-surface membrane fluidity in human erythrocytes. Methods: We used electron paramagnetic resonance spectroscopy and fatty acid spin probes (5-DS and 7-DS), the spectra of which are dependent on membrane fluidity. Results: The results showed a significant (p = 0.029) increase of membrane fluidity near the hydrophilic surface in erythrocytes treated with higher concentration of naringenin. In the deeper layer, just below the erythrocyte membrane phospholipid heads, both lower and higher concentration of naringenin significantly increased membrane fluidity (p = 0.036 and p = 0.028, respectively). Conclusions: These data document the positive and dose dependent effect of naringenin on near-surface membrane fluidity in human erythrocytes, recommending its use in the cardiovascular conditions characterized by disturbed hemodynamics
Topological network alignment uncovers biological function and phylogeny
Sequence comparison and alignment has had an enormous impact on our
understanding of evolution, biology, and disease. Comparison and alignment of
biological networks will likely have a similar impact. Existing network
alignments use information external to the networks, such as sequence, because
no good algorithm for purely topological alignment has yet been devised. In
this paper, we present a novel algorithm based solely on network topology, that
can be used to align any two networks. We apply it to biological networks to
produce by far the most complete topological alignments of biological networks
to date. We demonstrate that both species phylogeny and detailed biological
function of individual proteins can be extracted from our alignments.
Topology-based alignments have the potential to provide a completely new,
independent source of phylogenetic information. Our alignment of the
protein-protein interaction networks of two very different species--yeast and
human--indicate that even distant species share a surprising amount of network
topology with each other, suggesting broad similarities in internal cellular
wiring across all life on Earth.Comment: Algorithm explained in more details. Additional analysis adde
Supplementary material for the article: Milenković, M.; Shcherbakov, I. N.; Popov, L. D.; Levchenkov, S. I.; Borodkin, S. A.; Alexandrov, G. G. Synthesis, Characterization and Crystal Structures of Ni(II) and Cu(I) Complexes with the Condensation Product of 2-(Diphenylphosphino)Benzaldehyde and 1-Hydrazinophthalazine. Polyhedron 2017, 121, 278–284. https://doi.org/10.1016/j.poly.2016.10.020
Supplementary material for: [https://doi.org/10.1016/j.poly.2016.10.020]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2368]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3256
An Introductory Guide to Aligning Networks Using SANA, the Simulated Annealing Network Aligner.
Sequence alignment has had an enormous impact on our understanding of biology, evolution, and disease. The alignment of biological networks holds similar promise. Biological networks generally model interactions between biomolecules such as proteins, genes, metabolites, or mRNAs. There is strong evidence that the network topology-the "structure" of the network-is correlated with the functions performed, so that network topology can be used to help predict or understand function. However, unlike sequence comparison and alignment-which is an essentially solved problem-network comparison and alignment is an NP-complete problem for which heuristic algorithms must be used.Here we introduce SANA, the Simulated Annealing Network Aligner. SANA is one of many algorithms proposed for the arena of biological network alignment. In the context of global network alignment, SANA stands out for its speed, memory efficiency, ease-of-use, and flexibility in the arena of producing alignments between two or more networks. SANA produces better alignments in minutes on a laptop than most other algorithms can produce in hours or days of CPU time on large server-class machines. We walk the user through how to use SANA for several types of biomolecular networks
Recommended from our members
Experimental validation of the recovery effect in batteries for wearable sensors and healthcare devices discovering the existence of hidden time constants
Wearable sensors and healthcare devices use small lightweight batteries to power their typical operations of monitoring and tracking. It becomes absolutely vital to effectively utilise all the available battery charge for device longevity between charges. The electrochemical recovery effect enables the extraction of more power from the battery when implementing idle times in between use cycles, and has been used to develop various power management techniques. However, there is no evidence concerning the actual increase in available power that can be attained using the recovery effect. Also, this property cannot be generalised on all the battery chemistries since it is an innate phenomenon, relying on the anode/cathode material. Indeed recent developments suggest that recovery effect does not exist at all. This paper presents experimental results to verify the presence and level of the recovery effect in commonly used battery chemistries in wearable sensors and healthcare devices. The results have revealed that the recovery effect significantly does exist in certain batteries, and importantly we show that it is also comprised of two different time constants. This novel finding has important implications for the development of power management techniques that utilise the recovery effect with application in a large range of battery devices
Supplementary data for article: Romanović, M. Č.; Čobeljić, B. R.; Pevec, A.; Turel, I.; Spasojević, V.; Tsaturyan, A. A.; Shcherbakov, I. N.; Anđelković, K. K.; Milenković, M.; Radanović, D.; et al. Synthesis, Crystal Structure, Magnetic Properties and DFT Study of Dinuclear Ni(II) Complex with the Condensation Product of 2-Quinolinecarboxaldehyde and Girard’s T Reagent. Polyhedron 2017, 128, 30–37. https://doi.org/10.1016/j.poly.2017.02.039
Supplementary material for: [https://doi.org/10.1016/j.poly.2017.02.039]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2455]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3100
Connection of Solar Activities and Forest Fires in 2018: Events in the USA (California), Portugal and Greece
The impact of solar activity on environmental processes is difficult to understand and complex for empirical modeling. This study aimed to establish forecast models of the meteorological conditions in the forest fire areas based on the solar activity parameters applying the neural networks approach. During July and August 2018, severe forest fires simultaneously occurred in the State of California (USA), Portugal, and Greece. Air temperature and humidity data together with solar parameters (integral flux of solar protons, differential electron flux and proton flux, solar wind plasma parameters, and solar radio flux at 10.7 cm data) were used in long short-term memory (LSTM) recurrent neural network ensembles. It is found that solar activity mostly affects the humidity for two stations in California and Portugal (an increase in the integral flux of solar protons of > 30 MeV by 10% increases the humidity by 3.25%, 1.65%, and 1.57%, respectively). Furthermore, an increase in air temperature of 10% increases the humidity by 2.55%, 2.01%, and 0.26%, respectively. It is shown that temperature is less sensitive to changes in solar parameters but depends on previous conditions (previous increase of 10% increases the current temperature by 0.75%, 0.34%, and 0.33%, respectively). Humidity in Greece is mostly impacted by solar flux F10.7 cm and previous values of humidity. An increase in these factors by 10% will lead to a decrease in the humidity of 3.89% or an increase of 1.31%, while air temperature mostly depends on ion temperature. If this factor increases by 10%, it will lead to air temperature rising by 0.42%
Supplementary data for the article: Uraev, A. I.; Nefedov, S. E.; Lyssenko, K. A.; Vlasenko, V. G.; Ikorskii, V. N.; Garnovskii, D. A.; Makarova, N. I.; Levchenkov, S. I.; Shcherbakov, I. N.; Milenković, M. R.; Borodkin, G. S. Synthesis, Structure, Spectroscopic Studies and Magnetic Properties of Cu2N2O4-, Cu2N2O2(S2)-, Cu2N2S4-Chromophores Based on Aminomethylene Derivatives of Pyrazole-5-One(Thione). Polyhedron 2020, 188, 114623. https://doi.org/10.1016/j.poly.2020.114623
Supplementary material for: [https://doi.org/10.1016/j.poly.2020.114623]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4221
- …