3,189 research outputs found
Confocal laser scanning microscope, raman microscopy and western blotting to evaluate inflammatory response after myocardial infarction
Cardiac muscle necrosis is associated with inflammatory cascade that clears the infarct from dead
cells and matrix debris, and then replaces the damaged tissue with scar, through three overlapping phases: the
inflammatory phase, the proliferative phase and the maturation phase.
Western blotting, laser confocal microscopy, Raman microscopy are valuable tools for studying the inflammatory
response following myocardial infarction both humoral and cellular phase, allowing the identification and
semiquantitative analysis of proteins produced during the inflammatory cascade activation and the topographical distribution
and expression of proteins and cells involved in myocardial inflammation. Confocal laser scanning microscopy
(CLSM) is a relatively new technique for microscopic imaging, that allows greater resolution, optical sectioning of the
sample and three-dimensional reconstruction of the same sample. Western blotting used to detect the presence of a specific
protein with antibody-antigen interaction in the midst of a complex protein mixture extracted from cells, produced
semi-quantitative data quite easy to interpret. Confocal Raman microscopy combines the three-dimensional optical resolution
of confocal microscopy and the sensitivity to molecular vibrations, which characterizes Raman spectroscopy.
The combined use of western blotting and confocal microscope allows detecting the presence of proteins in the sample
and trying to observe the exact location within the tissue, or the topographical distribution of the same. Once demonstrated
the presence of proteins (cytokines, chemokines, etc.) is important to know the topographical distribution, obtaining in this
way additional information regarding the extension of the inflammatory process in function of the time stayed from the
time of myocardial infarction. These methods may be useful to study and define the expression of a wide range of inflammatory
mediators at several different timepoints providing a more detailed analysis of the time course of the infarct
Heat Sensing Receptor TRPV1 Is a Mediator of Thermotaxis in Human Spermatozoa
The molecular bases of sperm thermotaxis, the temperature-oriented cell motility, are currently under investigation. Thermal perception relies on a subclass of the transient receptor potential [TRP] channels, whose member TRPV1 is acknowledged as the heat sensing receptor. Here we investigated the involvement of TRPV1 in human sperm thermotaxis. We obtained semen samples from 16 normozoospermic subjects attending an infertility survey programme, testis biopsies from 6 patients with testicular germ cell cancer and testis fine needle aspirates from 6 patients with obstructive azoospermia undergoing assisted reproductive technologies. Expression of TRPV1 mRNA was assessed by RT-PCR. Protein expression of TRPV1 was determined by western blot, flow cytometry and immunofluorescence. Sperm motility was assessed by Sperm Class Analyser. Acrosome reaction, apoptosis and intracellular-Ca2+ content were assessed by flow cytometry. We found that TRPV1 mRNA and protein were highly expressed in the testis, in both Sertoli cells and germ-line cells. Moreover, compared to no-gradient controls at 31°C or 37°C (Ctrl 31°C and Ctrl 37°C respectively), sperm migration towards a temperature gradient of 31-37°C (T gradient) in non-capacitated conditions selected a higher number of cells (14,9 ± 4,2×106 cells T gradient vs 5,1± 0,3×106 cells Ctrl 31°C and 5,71±0,74×106 cells Ctrl 37°C; P = 0,039). Capacitation amplified the migrating capability towards the T gradient. Sperms migrated towards the T gradient showed enriched levels of both TRPV1 protein and mRNA. In addition, sperm cells were able to migrate toward a gradient of capsaicin, a specific agonist of TRPV1, whilst capsazepine, a specific agonist of TRPV1, blocked this effect. Finally, capsazepine severely blunted migration towards T gradient without abolishing. These results suggest that TRPV1 may represent a facilitating mediator of sperm thermotaxis
One perception, two perspectives: measuring psychological contract dimensionality through the Psychological Contract Content Questionnaire
The present study aims to contribute to the validity strengthening of a psychological contract measure, assessing the dimensionality of the item structure of the Psychological Contract Content Questionnaire (PCCQ). According to the authors (De Vos, Buyens, & Schalk, 2003), the scale consists of two theoretical dimensions, one to measure perceived employer inducement (PEI) and the other to measure perceived employee contributions (PEC), both from the employee's perception, each divided into five content areas. Different structure models were tested in newcomers (police officers working in the Penitentiary Administration attending a one-year training) in two different stages of their entry: at their early entrance (three weeks, TI; 436 respondents) and after their encounter with the operative environment (eight months, T2; 519 respondents). Analyses were carried out using nonparametric item response theory (IRT) approach and multidimensional IRT approach. Results showed that psychological contract is a single latent construct that describes the general perception that the employee has about his/her relationship with the organization and reciprocal obligations fulfilment
Drag Reduction by Polymers in Turbulent Channel Flows: Energy Redistribution Between Invariant Empirical Modes
We address the phenomenon of drag reduction by dilute polymeric additive to
turbulent flows, using Direct Numerical Simulations (DNS) of the FENE-P model
of viscoelastic flows. It had been amply demonstrated that these model
equations reproduce the phenomenon, but the results of DNS were not analyzed so
far with the goal of interpreting the phenomenon. In order to construct a
useful framework for the understanding of drag reduction we initiate in this
paper an investigation of the most important modes that are sustained in the
viscoelastic and Newtonian turbulent flows respectively. The modes are obtained
empirically using the Karhunen-Loeve decomposition, allowing us to compare the
most energetic modes in the viscoelastic and Newtonian flows. The main finding
of the present study is that the spatial profile of the most energetic modes is
hardly changed between the two flows. What changes is the energy associated
with these modes, and their relative ordering in the decreasing order from the
most energetic to the least. Modes that are highly excited in one flow can be
strongly suppressed in the other, and vice versa. This dramatic energy
redistribution is an important clue to the mechanism of drag reduction as is
proposed in this paper. In particular there is an enhancement of the energy
containing modes in the viscoelastic flow compared to the Newtonian one; drag
reduction is seen in the energy containing modes rather than the dissipative
modes as proposed in some previous theories.Comment: 11 pages, 13 figures, included, PRE, submitted, REVTeX
On the signature of tensile blobs in the scattering function of a stretched polymer
We present Monte Carlo data for a linear chain with excluded volume subjected
to a uniform stretching. Simulation of long chains (up to 6000 beads) at high
stretching allows us to observe the signature of tensile blobs as a crossover
in the scaling behavior of the chain scattering function for wave vectors
perpendicular to stretching. These results and corresponding ones in the
stretching direction allow us to verify for the first time Pincus prediction on
scaling inside blobs. Outside blobs, the scattering function is well described
by the Debye function for a stretched ideal chain.Comment: 4 pages, 4 figures, to appear in Physical Review Letter
Genotype-specific changes associated to early synthesis of autotetraploids in wild potato species
Polyploidy is an important factor in plant evolution that may trigger drastic genome reorganization and phenotypic differentiation. In the last decade, extensive studies have been carried to understand the consequences of allopolyploidization, where the effects of ploidy change may be confounded by interspecific hybridization. By contrast, less is known on autopolyploidization, which only involves doubling of homologous chromosomes. This study was undertaken to assess leaf anatomical modifications and gene expression changes occurring after doubling the somatic chromosome complement of diploid (2n = 2x = 24) potato species Solanum commersonii Dunal and S. bulbocastanum Dunal. Polyploidization did not induce qualitative changes in leaf structure and, for several leaf traits, anatomic modifications were stochastic. In addition, in both species a diploid superiority was generally observed, suggesting the occurrence of a high-ploidy syndrome. Expression change study was carried out on eight important cell cycle-regulatory genes in plant. It revealed a strong alteration of the expression patterns in the 4x genotypes with respect to the 2x parents. Changes often exceed the twofold, with no consistent trend towards up- or down regulation when comparing 2x vis-Ă -vis 4x. We discuss the possible relevance of epigenetic changes in controlling the expression of duplicated genes
Extremely large extinction efficiency and field enhancement in terahertz resonant dipole nanoantennas
The distinctive ability of nanometallic structures to manipulate light at the nanoscale has recently promoted their use for a spectacular set of applications in a wide range of areas of research including artificial optical materials, nano-imaging, biosensing, and nonlinear optics. Here we transfer this concept to the terahertz spectral region, demonstrating a metal nanostructure in shape of a dipole nanoantenna, which can efficiently resonate at terahertz frequencies, showing an effective cross section >100 times larger than its geometrical area, and a field enhancement factor of ~280, confined on a lateral section of ~λ/1,000. These results lead to immediate applications in terahertz artificial materials exhibiting giant dichroism, suggest the use of dipole nanoantennas in nanostructure-based terahertz metamaterials, and pave the way for nanoantenna-enhanced terahertz few-molecule spectroscopy and localized terahertz nonlinear optics
The Water Bugs (Heteroptera: Nepomorpha) of the Guyana Region
NEPOMORPHA OF THE GUYANA REGION
The Nepomorpha of the Guyana Region are keyed out and described. In addition distributional, faunistical and comparative notes on the species are given.
New species and subspecies: Ochterus aeneifrons surinamensis, O. tenebrosus; Limnocoris fittkaui surinamensis; Ranatra adelomorpha; Neoplea globoidea; Buenoa amnigenopsis; Tenagobia pseudoromani from Suriname and Ranatra ornitheia from Guyana.
New synonyms (junior ones between parenthesis): Gelaslocorus flavus flavus Guér. (G. nebulosus nebulosus Guér.); Pelocoris impicticollis Stål (P. horváthi Mont.), P. poeyi (Guér.) not identical with P. femoratus (P.-B.) (P. convexus Nieser), P. procurrens White (P. minutus Mont.); Belostoma bicavum Lauck ( B. parvoculum Lauck); Ranatra doesburgi De Carlo (R. usingeri De C.), R. macrophthalma H.-S. (R. surinamensis De C.), R. mediana Mont. (R. williamsi Kuitert), R. obscura Mont. (R. annulipes White 1879 not Stål), R. sarmentoi De C. (R. ameghinoi De C.); Buenoa amnigenopsis n. sp. ( B. amnigenus Nieser 1968, 1970 not White), B. amnigenus (White) (B. amnigenoidea Nieser 1970), B. nitida Truxal (B. doesburgi Nieser); Heterocorixa surinamensis Nieser ( H. boliviensis Nieser 1970 not Hungerford); Tenagobia incerta Lundbl. ( T. signata and T. serrata in part, Nieser 1970 not White and Deay respectively), T. socialis (White) (T. serrata in part, Nieser 1970 not Deay)
Scar functions in the Bunimovich Stadium billiard
In the context of the semiclassical theory of short periodic orbits, scar
functions play a crucial role. These wavefunctions live in the neighbourhood of
the trajectories, resembling the hyperbolic structure of the phase space in
their immediate vicinity. This property makes them extremely suitable for
investigating chaotic eigenfunctions. On the other hand, for all practical
purposes reductions to Poincare sections become essential. Here we give a
detailed explanation of resonances and scar functions construction in the
Bunimovich stadium billiard and the corresponding reduction to the boundary.
Moreover, we develop a method that takes into account the departure of the
unstable and stable manifolds from the linear regime. This new feature extends
the validity of the expressions.Comment: 21 pages, 10 figure
How SARS-CoV-2 Infection Impacts the Management of Patients with Vulvar Cancer: Experience in a Third-Level Hospital of Southern Italy
: Background: Since February 2020, the spread of Coronavirus Disease 2019 (COVID-19) in Italy has induced the government to call for lockdown of any activity apart from primary needs, and changing the lives of each of us. All that has dramatically impacted the management of patients affected by cancer. Patients with vulvar cancer (VC) represent a particularly frail population because they are elderly and affected by multiple comorbidities. The aim of this study is to evaluate the clinical impact of the SARS-CoV-2 infection on VC patients in terms of delay or impossibility of carrying out the scheduled treatment. Methods: The medical records of patients affected by vulvar tumors, referred to "DAI Materno-Infantile" of AOU Federico II of Naples between February 2020 and January 2022 were retrospectively analyzed. The presence of a positive reverse transcription-polymerase chain reaction (RT-PCR) in nasopharyngeal swab defined the positivity to SARS-CoV-2. Results: Twenty-four patients with VC were analyzed and scheduled for treatment. The median age was 70.7 years (range: 59-80). Seven (29.2%) patients were diagnosed with SARS-CoV-2 infection: In three (42.8%) patients, the treatment was delayed with no apparent consequences, in four (57.2%), the treatment was delayed or changed due to cancer progression and, of these four, one died due to respiratory complications of COVID-19, and one died due to oncologic disease progression. Conclusion: COVID-19 caused, in most cases, significant delays in oncologic treatments and high mortality in our series of patients affected by VC
- …