42 research outputs found
Light propagation with non-minimal couplings in a two-component cosmic dark fluid with an Archimedean-type force and unlighted cosmological epochs
During the evolution of the universe there are at least two epochs during
which electromagnetic waves cannot scan the universe's internal structure
neither bring information to outside observers. The first epoch is when photons
are in local thermodynamic equilibrium with other particles, and the second is
when photon scattering by charged particles is strong. One can call these two
periods of cosmological time as standard unlighted epochs. After the last
scattering surface, photons become relic photons and turn into a source of
information about the universe. Unlighted cosmic epochs can also appear when
one considers non-minimal theories, i.e., theories in which the electromagnetic
field is coupled in an intricate way with the cosmological gravitational field.
By considering a cosmological model where the dark sector, i.e., the dark
energy and dark matter, self-interacts via an Archimedean-type force, and
taking into account a non-minimal coupling theory for the electromagnetic
field, we discuss the appearance of unlighted epochs. In the framework of our
non-minimal theory, a three-parameter non-minimal Einstein-Maxwell model, the
curvature coupling can be formulated in terms of an effective refraction index
n(t). Then, taking advantage of a well-known classical analogy, namely, in a
medium with n^2<0 electromagnetic waves do not propagate and their group
velocity, i.e., energy transfer velocity, has zero value at the boundary of the
corresponding zone, one can search for the unlighted epochs arising in the
interacting dark fluid cosmological model. We study here, both analytically and
numerically, cosmological models admitting unlighted epochs.Comment: 23 pages, 8 figure
Inducing the cosmological constant from five-dimensional Weyl space
We investigate the possibility of inducing the cosmological constant from
extra dimensions by embedding our four-dimensional Riemannian space-time into a
five-dimensional Weyl integrable space. Following approach of the induced
matter theory we show that when we go down from five to four dimensions, the
Weyl field may contribute both to the induced energy-tensor as well as to the
cosmological constant, or more generally, it may generate a time-dependent
cosmological parameter. As an application, we construct a simple cosmological
model which has some interesting properties.Comment: 7 page
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
Primary Structure Characterization Of Bothrops Jararacussu Snake Venom Lectin.
The complete amino acid sequence of the lectin from Bothrops jararacussu snake venom (BJcuL) is reported. The sequence was determined by Edman degradation and amino acid analysis of the S-carboxymethylated BJcuL derivative (RC-BJcuL) and from its peptides originated from enzymatic digestion. The sequence of amino acid residues showed that this lectin displays the invariant amino acid residues characterized in C-type lectins. Amino acids analysis revealed a high content of acidic amino acids and leucine. These findings suggest that BJcuL, like other snake venom lectins, possesses structural similarities to the carbohydrate recognition domain (CRD) of calcium-dependent animal lectins belonging to the C-type beta-galactoside binding lectin family.2143-5
Oedematogenic Activity Induced By Kunitz-type Inhibitors From Dimorphandra Mollis Seeds.
Proteinase inhibitors from plants represent a form of storage protein or may be involved in plant defense mechanisms against pests and diseases. In this study, we have investigated the oedematogenic activity of DMTI (20 kDa) and DMTI-II (23 kDa), two serine proteinases inhibitors isolated from Dimorphandra mollis (Leguminosae-Mimosoideae) seeds, belonging to the Kunitz family. Paw oedema was induced in male Wistar rats, and measured before and selected times after injection of the proteinase inhibitors. Injection of DMTI-II (3-100 microg/paw) induced a dose-dependent rat paw oedema of rapid onset and short duration, whereas DMTI (3-100 microg/paw) caused a discrete response. The histamine/5-HT receptor antagonist cyproheptadine (2 mg/kg) markedly reduced the DMTI-II-induced oedema. The bradykinin B2 receptor antagonist JE 049 (0.6 mg/kg), the tachykinin NK1 receptor antagonist SR140333 (100 microg/kg) or the NK2 receptor antagonist SR48968 (1 mg/kg) all significantly reduced the DMTI-II-induced oedema. Depletion of sensory neuropeptides by capsaicin also resulted in a significant reduction of oedema formation. In rat isolated peritoneal mast cells, DMTI-II failed to directly release histamine. In conclusion, the proteinase inhibitor DMTI-II induces rat paw oedema by triggering the formation of different inflammatory mediators and pathways, where mast cells and sensory fibers seem to play a pivotal role.47150-
Web Based Theoretical Protein pI, MW and 2DE Map
Copyright: © 2009 Brum IJB, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Cloning, Expression, And Structural Analysis Of Recombinant Bjcul, A C-type Lectin From The Bothrops Jararacussu Snake Venom.
The lactose-binding lectin from Bothrops jararacussu venom (BJcuL) is a homodimer belonging to group VII of the c-type animal lectins. BJcuL has also been shown to serve as an interesting tool for combating tumor progression by inhibiting cancer and endothelial cell growth. However, detailed structural studies of BJcuL and its biological mechanisms of cytotoxicity are yet to be reported, perhaps because of the non-availability of recombinant proteins in necessary quantities. Intending to increase the present information about structural and consequently the understating of biological studies, the cDNA coding for BJcuL from a venom gland has been cloned and sequenced. The mature protein-coding region was amplified by PCR with specific oligonucleotides, and subcloned into the pET-15b vector to express the recombinant BJcuL in Escherichia coli BL21 (DE3). The deduced amino acid sequence exhibits a high degree of sequence identity with c-type lectins (CTLs) and c-type lectin-like domains (CTLDs). An insoluble and inactive 18.5-kDa protein was overexpressed after 1.0mM IPTG induction. The recombinant BJcuL was recovered and denatured in a buffer with 6M urea and purified on a nickel-affinity column. Protein refolding was carried out on this column, during procedure purification, followed by dialysis against CTBS and then by gel filtration for separation of the active dimmer. The refolding process of rBJcuL and the analysis of its structure were confirmed by biological assay, circular dichroism, and MALDI-TOF.35344-5
Proteome analysis of schizophrenia patients Wernicke's area reveals an energy metabolism dysregulation
Background: Schizophrenia is likely to be a consequence of DNA alterations that, together with environmental factors, will lead to protein expression differences and the ultimate establishment of the illness. The superior temporal gyrus is implicated in schizophrenia and executes functions such as the processing of speech, language skills and sound processing. Methods: We performed an individual comparative proteome analysis using two-dimensional gel electrophoresis of 9 schizophrenia and 6 healthy control patients' left posterior superior temporal gyrus (Wernicke's area - BA22p) identifying by mass spectrometry several protein expression alterations that could be related to the disease. Results: Our analysis revealed 11 downregulated and 14 upregulated proteins, most of them related to energy metabolism. Whereas many of the identified proteins have been previously implicated in schizophrenia, such as fructose-bisphosphate aldolase C, creatine kinase and neuron-specific enolase, new putative disease markers were also identified such as dihydrolipoyl dehydrogenase, tropomyosin 3, breast cancer metastasis-suppressor 1, heterogeneous nuclear ribonucleoproteins C1/C2 and phosphate carrier protein, mitochondrial precursor. Besides, the differential expression of peroxiredoxin 6 (PRDX6) and glial fibrillary acidic protein (GFAP) were confirmed by western blot in schizophrenia prefrontal cortex. Conclusion: Our data supports a dysregulation of energy metabolism in schizophrenia as well as suggests new markers that may contribute to a better understanding of this complex disease.The authors thank ABADHS (Associação Beneficente Alzira Denise Hertzog da Silva), FAPESP (Fundação de Amparo a Pesquisa do Estado de SĂŁo Paulo) and CNPq (Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico) for supporting this project. Moreover, we thank Dr. Alessandro dos Santos Farias for the support in statistical tests and we appreciate the tissue donors' families who become possible our studies
Proteome analysis of schizophrenia patients Wernicke's area reveals an energy metabolism dysregulation
Abstract Background Schizophrenia is likely to be a consequence of DNA alterations that, together with environmental factors, will lead to protein expression differences and the ultimate establishment of the illness. The superior temporal gyrus is implicated in schizophrenia and executes functions such as the processing of speech, language skills and sound processing. Methods We performed an individual comparative proteome analysis using two-dimensional gel electrophoresis of 9 schizophrenia and 6 healthy control patients' left posterior superior temporal gyrus (Wernicke's area â BA22p) identifying by mass spectrometry several protein expression alterations that could be related to the disease. Results Our analysis revealed 11 downregulated and 14 upregulated proteins, most of them related to energy metabolism. Whereas many of the identified proteins have been previously implicated in schizophrenia, such as fructose-bisphosphate aldolase C, creatine kinase and neuron-specific enolase, new putative disease markers were also identified such as dihydrolipoyl dehydrogenase, tropomyosin 3, breast cancer metastasis-suppressor 1, heterogeneous nuclear ribonucleoproteins C1/C2 and phosphate carrier protein, mitochondrial precursor. Besides, the differential expression of peroxiredoxin 6 (PRDX6) and glial fibrillary acidic protein (GFAP) were confirmed by western blot in schizophrenia prefrontal cortex. Conclusion Our data supports a dysregulation of energy metabolism in schizophrenia as well as suggests new markers that may contribute to a better understanding of this complex disease.</p