4,146 research outputs found
Shiga Toxin Detection Methods : A Short Review
The Shiga toxins comprise a family of related protein toxins secreted by
certain types of bacteria. Shigella dysenteriae, some strain of Escherichia
coli and other bacterias can express toxins which caused serious complication
during the infection. Shiga toxin and the closely related Shiga-like toxins
represent a group of very similar cytotoxins that may play an important role in
diarrheal disease and hemolytic-uremic syndrome. The outbreaks caused by this
toxin raised serious public health crisis and caused economic losses. These
toxins have the same biologic activities and according to recent studies also
share the same binding receptor, globotriosyl ceramide (Gb3). Rapid detection
of food contamination is therefore relevant for the containment of food-borne
pathogens. The conventional methods to detect pathogens, such as
microbiological and biochemical identification are time-consuming and
laborious. The immunological or nucleic acid-based techniques require extensive
sample preparation and are not amenable to miniaturization for on-site
detection. In the present are necessary of techniques of rapid identification,
simple and sensitive which can be employed in the countryside with
minimally-sophisticated instrumentation. Biosensors have shown tremendous
promise to overcome these limitations and are being aggressively studied to
provide rapid, reliable and sensitive detection platforms for such
applications.Comment: 16 pages, 2 figure
Recommended from our members
Composite polymer membranes for laserinduced fluorescence thermometry
We demonstrate a modified version of laser-induced fluorescence thermometry (LIFT) for mapping temperature gradients in the vicinity of small photothermal devices. Our approach is based on temperature sensitive fluorescent membranes fabricated with rhodamine B and polydimethylsiloxane (PDMS). Relevant membrane features for LIFT, such as temperature sensitivity, thermal quenching and photobleaching are presented for a range of 25 °C to 90 °C, and their performance is evaluated upon obtaining the temperature gradients produced in the proximity of optical fiber micro-heaters. Our results show that temperature measurements in regions as small as 750 μm x 650 μm, with a temperature resolution of 1 °C, can be readily obtained
Quark mixings as a test of a new symmetry of quark Yukawa couplings
Based on the hierarchy exhibited by quarks masses at low energies, we assume
that Yukawa couplings of up and down quarks are related by
at grand unification scales. This ansatz gives rise to a symmetrical CKM matrix
at the grand unification (GU) scale. Using three specific models as
illustrative examples for the evolution down to low energies, we obtain the
entries and asymmetries of the CKM matrix which are in very good agreement with
their measured values. This indicates that the small asymmetry of the CKM
matrix at low energies may be the effect of the renormalization group evolution
only.Comment: LaTeX file, 10 pages including 1 tabl
Integrating clinical research in an operative screening and diagnostic breast imaging department: First experience, results and perspectives using microwave imaging.
Clinical research is crucial for evaluating new medical procedures and devices. It is important for healthcare units and hospitals to minimize the disruptions caused by conducting clinical studies; however, complex clinical pathways require dedicated recruitment and study designs.This work presents the effective introduction of novel microwave breast imaging (MBI), via MammoWave apparatus, into the clinical routine of an operative screening and diagnostic breast imaging department for conducting a multicentric clinical study. Microwave breast imaging, using MammoWave apparatus, was performed on volunteers coming from different clinical pathways. Clinical data, comprising demographics and conventional radiologic reports (used as reference standard), was collected; a satisfaction questionnaire was filled by every volunteer. Microwave images were analyzed by an automatic clinical decision support system, which quantified their corresponding features to discriminate between breasts with no relevant radiological findings (NF) and breasts with described findings (WF). Conventional breast imaging (DBT, US, MRI) and MBI were performed and adapted to assure best clinical practices and optimum pathways. 180 volunteers, both symptomatic and asymptomatic, were enrolled in the study. After microwave images' quality assessment, 48 NF (15 dense) and 169 WF (88 dense) breasts were used for the prospective study; 48 (18 dense) breasts suffered from a histology-confirmed carcinoma. An overall sensitivity of 85.8 % in breasts lesions' detection was achieved by the microwave imaging apparatus. An optimum recruitment strategy was implemented to assess MBI. Future trials may show the clinical usefulness of microwave imaging, which may play an important role in breast screening. [Abstract copyright: © 2023 The Authors.
Hydrothermal–microwave processing for starch extraction from mexican avocado seeds: operational conditions and characterization
Avocado seeds are an agroindustrial residue widely produced in Mexico that are causing various environmental problems due to their accumulation. The evaluation of avocado residues to recover biopolymers by microwave-assisted extraction (MAE) and the characterization of avocado starch properties were studied in the present work. A central-composite design was used to optimize the MAE process. Moreover, a comparison was performed between MAE non-isothermal mode (NO–ISO) and conventional extraction. Starch optimization by MAE was obtained at 161.09 °C for 56.23 min with an extraction yield of 49.52% ± 0.69%, while with NO–ISO at 161 °C was obtained 45.75% ± 2.18%. Conventional extraction was 39.04% ± 2.22%. Compared with conventional starch, MAE starch showed similar proprieties and molecular spectra. In contrast, MAE starch showed high solubility, low water absorption capacity, a non-granular structure with small particle size (<2 μm) and polydispersity of fragments at different sizes of polymers. Therefore, MAE is a viable technology to extract the starch, and avocado seed can be considered an excellent starch source for the development of novel functional foods, contributing to promoting sustainability
across the food chain.N/Ainfo:eu-repo/semantics/publishedVersio
Does native Trypanosoma cruzi calreticulin mediate growth inhibition of a mammary tumor during infection?
Indexación: Web of Science.Background: For several decades now an antagonism between Trypanosoma cruzi infection and tumor development has been detected. The molecular basis of this phenomenon remained basically unknown until our proposal that T. cruzi Calreticulin (TcCRT), an endoplasmic reticulum-resident chaperone, translocated-externalized by the parasite, may mediate at least an important part of this effect. Thus, recombinant TcCRT (rTcCRT) has important in vivo antiangiogenic and antitumor activities. However, the relevant question whether the in vivo antitumor effect of T. cruzi infection is indeed mediated by the native chaperone (nTcCRT), remains open. Herein, by using specific modified anti-rTcCRT antibodies (Abs), we have neutralized the antitumor activity of T. cruzi infection and extracts thereof, thus identifying nTcCRT as a valid mediator of this effect.
Methods: Polyclonal anti-rTcCRT F(ab')(2) Ab fragments were used to reverse the capacity of rTcCRT to inhibit EAhy926 endothelial cell (EC) proliferation, as detected by BrdU uptake. Using these F(ab')(2) fragments, we also challenged the capacity of nTcCRT, during T. cruzi infection, to inhibit the growth of an aggressive mammary adenocarcinoma cell line (TA3-MTXR) in mice. Moreover, we determined the capacity of anti-rTcCRT Abs to reverse the antitumor effect of an epimastigote extract (EE). Finally, the effects of these treatments on tumor histology were evaluated.
Results: The rTcCRT capacity to inhibit ECs proliferation was reversed by anti-rTcCRT F(ab')(2) Ab fragments, thus defining them as valid probes to interfere in vivo with this important TcCRT function. Consequently, during infection, these Ab fragments also reversed the in vivo experimental mammary tumor growth. Moreover, anti-rTcCRT Abs also neutralized the antitumor effect of an EE, again identifying the chaperone protein as an important mediator of this anti mammary tumor effect. Finally, as determined by conventional histological parameters, in infected animals and in those treated with EE, less invasive tumors were observed while, as expected, treatment with F(ab')(2) Ab fragments increased malignancy.
Conclusion: We have identified translocated/externalized nTcCRT as responsible for at least an important part of the anti mammary tumor effect of the chaperone observed during experimental infections with T. cruzi.http://bmccancer.biomedcentral.com/articles/10.1186/s12885-016-2764-
Dielectric Characterization of Breast Biopsied Tissues as Pre-Pathological Aid in Early Cancer Detection: A Blinded Feasibility Study
Dielectric characterization has significant potential in several medical applications, providing valuable insights into the electromagnetic properties of biological tissues for disease diagnosis, treatment planning, and monitoring of therapeutic interventions. This work presents the use of a custom-designed electromagnetic characterization system, based on an open-ended coaxial probe, for discriminating between benign and malignant breast tissues in a clinical setting. The probe’s development involved a well-balanced compromise between physical feasibility and its combined use with a reconstruction algorithm known as the virtual transmission line model (VTLM). Immediately following the biopsy procedure, the dielectric properties of the breast tissues were reconstructed, enabling tissue discrimination based on a rule-of-thumb using the obtained dielectric parameters. A comparative analysis was then performed by analyzing the outcomes of the dielectric investigation with respect to conventional histological results. The experimental procedure took place at Complejo Hospitalario Universitario de Toledo—Hospital Virgen de la Salud, Spain, where excised breast tissues were collected and subsequently analyzed using the dielectric characterization system. A comprehensive statistical evaluation of the probe’s performance was carried out, obtaining a sensitivity, specificity, and accuracy of 81.6%, 61.5%, and 73.4%, respectively, compared to conventional histological assessment, considered as the gold standard in this investigation
Metallicity of low-mass stars in Orion
Determining the metal content of low-mass members of young associations
provides a tool that addresses different issues, such as triggered star
formation or the link between the metal-rich nature of planet-host stars and
the early phases of planet formation. The Orion complex is a well known example
of possible triggered star formation and is known to host a rich variety of
proto-planetary disks around its low-mass stars. Available metallicity
measurements yield discrepant results. We analyzed FLAMES/UVES and Giraffe
spectra of low-mass members of three groups/clusters belonging to the Orion
association. Our goal is the homogeneous determination of the metallicity of
the sample stars, which allows us to look for [Fe/H] differences between the
three regions and for the possible presence of metal-rich stars. Nine members
of the ONC and one star each in the Ori cluster and OB1b subgroup
were analyzed. After the veiling determination, we retrieved the metallicity by
means of equivalent widths and/or spectral synthesis using MOOG. We obtain an
average metallicity for the ONC [Fe/H]=-0.01\pm 0.04. No metal-rich stars were
detected and the dispersion within our sample is consistent with measurement
uncertainties. The metallicity of the Ori member is also solar, while
the OB1b star has an [Fe/H] significantly below the ONC average. If confirmed
by additional [Fe/H] determinations in the OB1b subgroup, this result would
support the triggered star formation and the self-enrichment scenario for the
Orion complex.Comment: 13 pages, accepted for publication in A&
- …