563 research outputs found
Hot ductility and deformation behavior of C-Mn/Nb-microalloyed steel related to cracking during continuous casting
Hot ductility studies have been performed on C-Mn and C-Mn-Nb steels with an approach to simulate the effect of cooling conditions experienced by steel in secondary cooling zone during continuous casting. Thermal oscillations prior to tensile straining deteriorate hot ductility of steel by deepening and widening the hot ductility trough. C-Mn steels are found to exhibit ductility troughs in three distinct zones whereas C-Mn-Nb steel shows drop in ductility only at low temperature in the vicinity of ferrite transformation temperatures. Start of ferrite transformation in steels causes yield ratio to increase while work hardening rates and strength coefficient decrease with decrease in test temperature in presence of thermal oscillation prior to tensile testing. Inhibition of recrystallization due to build-up of AlN particles along with the presence of MnS particles in structure and low work hardening rates causes embrittlement of steel in austenitic range. Alloying elements enhancing work hardening rates in austenitic range can be promoted to
improve hot ductility. The presence of low melting phase saturated with impurities along the austenitic grain boundaries causes intergranular fracture at high temperature in C-Mn steels
Visualization and measurement of the cell-free layer (CFL) in a microchannel network
In the past years, in vitro blood studies have revealed several significant hemodynamic phenomena that have played a key role in recent developments of biomedical microdevices for cells separation, sorting and analysis. However, the blood flow phenomena happening in complex geometries, such as microchannel networks, have not been fully understood. Thus, it is important to investigate in detail the blood flow behavior occurring at microchannel networks. In the present study, by using a high-speed video microscopy system, we have used two working fluids with different haematocrit (1% Hct and 15% Hct) and we have investigated the cell-free layer (CFL) in a microchannel network composed by asymmetric bifurcations. By using the Z Project method from the image analysis software ImageJ, it was possible to conclude that the successive bifurcations and confluences influence the formation of the CFL not only along the upper and lower wall of the microchannel but also at the region immediately downstream of the confluence apex.The authors acknowledge the financial support provided by the project POCI-01-0145 FEDER-016861 (with associated reference PTDC/QEQ-FTT/4287/2014), UID/EMS/00532/2013 and UID/CEC/00319/2013 funded by FCT (Foundation for Science and Technology), through national funds (PIDDAC), and FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI). D. Bento acknowledges the PhD scholarship SFRH/BD/91192/2012 granted by FCT.
The authors also acknowledge the financial support provided by the project Nos. UID/EMS/00532/2013 and UID/EMS/04077/2013 and the project Nos. UID/EMS/00532/2013,
UID/EMS/04077/2013, POCI-01-0145-FEDER-007043, UID/CEC/00319/2013info:eu-repo/semantics/publishedVersio
Nodeless time-reversal symmetry breaking in the centrosymmetric superconductor Sc5Co4Si10 probed by muon-spin spectroscopy
Samarium-153 ethylenediamine tetramethylene phosphonate therapy for bone pain palliation in skeletal metastases
Samarium-153 ethylenediamine tetramethylene phosphonate therapy for bone pain palliation in skeletal metastases
BACKGROUND: Systemic therapy with radionuclides may be used for the
treatment of patients with painful skeletal metastases owing to its
efficacy, low cost and low toxicity. Imported radionuclides for pain
palliation, like Strontium-89 are expensive; particularly for
developing countries. In the Indian scenario, Samarium-153 (Sm-153) is
produced in our own reactors and as a result, it is readily available
and economical. AIM: We undertook this study to determine the
efficacy and toxicity of single-dose Sm-153 ethylenediamine
tetramethylene phosphonate as a palliative treatment for painful
skeletal metastases. MATERIALS AND METHODS: Eightysix patients with
painful skeletal metastases from various primaries, were treated with
Sm-153 EDTMP at a dose of 37 MBq/kg. The effects were evaluated
according to change in visual analogue pain score, analgesic
consumption, Karnofsky performance score, mobility score and blood
count tests, conducted regularly for 16 weeks. STATISTICS: Repeated
measures analysis. RESULTS: The overall response rates were 73%, while
complete response was seen in 12.4%. Reduction in analgesic consumption
with improvement in Karnofsky performance score and mobility score, was
seen in all responders. Response rates were 80.3 and 80.5% in breast
and prostate cancer, respectively. One case, each of Wilms tumor,
ovarian cancer, germ cell tumor testis, multiple myeloma, primitive
neuroectodermal tumor and oesophageal cancer, did not respond to
therapy. No serious side-effects were noted, except for fall in white
blood cell, platelet and haemoglobin counts, which gradually returned
to normal levels by six-eight weeks. CONCLUSION: Sm-153 EDTMP
provided effective palliation in 73% patients with painful bone
metastases: the major toxicity was temporary myelosuppression
Differential Expression of Vegfr-2 and Its Soluble Form in Preeclampsia
Several studies have suggested that the main features of preeclampsia (PE) are consequences of endothelial dysfunction related to excess circulating anti-angiogenic factors, most notably, soluble sVEGFR-1 (also known as sFlt-1) and soluble endoglin (sEng), as well as to decreased PlGF. Recently, soluble VEGF type 2 receptor (sVEGFR-2) has emerged as a crucial regulator of lymphangiogenesis. To date, however, there is a paucity of information on the changes of VEGFR-2 that occur during the clinical onset of PE. Therefore, the aim of our study was to characterize the plasma levels of VEGFR-2 in PE patients and to perform VEGFR-2 immunolocalization in placenta.By ELISA, we observed that the VEGFR-2 plasma levels were reduced during PE compared with normal gestational age matched pregnancies, whereas the VEGFR-1 and Eng plasma levels were increased. The dramatic drop in the VEGFR-1 levels shortly after delivery confirmed its placental origin. In contrast, the plasma levels of Eng and VEGFR-2 decreased only moderately during the early postpartum period. An RT-PCR analysis showed that the relative levels of VEGFR-1, sVEGFR-1 and Eng mRNA were increased in the placentas of women with severe PE. The relative levels of VEGFR-2 mRNA as well as expressing cells, were similar in both groups. We also made the novel finding that a recently described alternatively spliced VEGFR-2 mRNA variant was present at lower relative levels in the preeclamptic placentas.Our results indicate that the plasma levels of anti-angiogenic factors, particularly VEGFR-1 and VEGFR-2, behave in different ways after delivery. The rapid decrease in plasma VEGFR-1 levels appears to be a consequence of the delivery of the placenta. The persistent circulating levels of VEGFR-2 suggest a maternal endothelial origin of this peptide. The decreased VEGFR-2 plasma levels in preeclamptic women may serve as a marker of endothelial dysfunction
Immunogenicity and Efficacy of Single Antigen Gp63, Polytope and PolytopeHSP70 DNA Vaccines against Visceral Leishmaniasis in Experimental Mouse Model
Polytope approach of genetic immunization is a promising strategy for the
prevention of infectious disease as it is capable of generating effective cell
mediated immunity by delivering the T cell epitopes assembled in series.
Leishmaniasis is a significant world wide health problem for which no vaccine
exists. In this study we have compared immunogenicity and efficacy of three
types of DNA vaccines: single antigen Gp63 (Gp63/pcDNA), polytope (Poly/pcDNA)
and Polytope fused with hsp70 (Poly/hsp/pcDNA) against visceral leishmaniasis in
susceptible BALB/c mice. Mice vaccinated with these plasmids generated strong
Th1 immune response as seen by dominating IFN-Ξ³ over IL-10 cytokine.
Interestingly, cytotoxic responses generated by polytope DNA plasmid fused with
hsp70 of Leishmania donovani were significantly higher when
compared to polytope and single antigen Gp63 vaccine. Challenge studies revealed
that the parasite load in liver and spleen was significantly lower with
Poly/hsp/pcDNA vaccination compared to other vaccines. Therefore, our study
indicates that polytope DNA vaccine is a feasible, practical and effective
approach for visceral leishmaniasis
Isolation and characterisation of a human anti-idiotypic scFv used as a surrogate tumour antigen to elicit an anti-HER-2/neu humoral response in mice
Evaluation of Leishmania donovani Protein Disulfide Isomerase as a Potential Immunogenic Protein/Vaccine Candidate against Visceral Leishmaniasis
In Leishmania species, Protein disulfide isomerase (PDI) - a redox chaperone, is reported to be involved in its virulence and survival. This protein has also been identified, through proteomics, as a Th1 stimulatory protein in the soluble lysate of a clinical isolate of Leishmania donovani (LdPDI). In the present study, the molecular characterization of LdPDI was carried out and the immunogenicity of recombinant LdPDI (rLdPDI) was assessed by lymphocyte proliferation assay (LTT), nitric oxide (NO) production, estimation of Th1 cytokines (IFN-Ξ³ and IL-12) as well as IL-10 in PBMCs of cured/endemic/infected Leishmania patients and cured L. donovani infected hamsters. A significantly higher proliferative response against rLdPDI as well as elevated levels of IFN-Ξ³ and IL-12 were observed. The level of IL-10 was found to be highly down regulated in response to rLdPDI. A significant increase in the level of NO production in stimulated hamster macrophages as well as IgG2 antibody and a low level of IgG1 in cured patient's serum was observed. Higher level of IgG2 antibody indicated its Th1 stimulatory potential. The efficacy of pcDNA-LdPDI construct was further evaluated for its prophylactic potential. Vaccination with this construct conferred remarkably good prophylactic efficacy (βΌ90%) and generated a robust cellular immune response with significant increases in the levels of iNOS transcript as well as TNF-Ξ±, IFN-Ξ³ and IL-12 cytokines. This was further supported by the high level of IgG2 antibody in vaccinated animals. The in vitro as well as in vivo results thus indicate that LdPDI may be exploited as a potential vaccine candidate against visceral Leishmaniasis (VL)
- β¦