5,932 research outputs found
Some remarks on particle size effects on the abrasion of a range of Fe based alloys
The low-stress three body abrasion behaviour of a range of steels was investigated. The tests were carried out in a rubber wheel tester (according to ASTM G65-94, reapproved in 2000) at room temperature. The abrasive particles used were angular alumina particles of four different sizes. The results showed that, in general, the smaller particles (50 8m and 125 8m average size) caused more damage. With these particles, observations of surface morphology indicarted a more intense cutting and ploughing action, leading to more damage, whereas bigger particles i.e. larger 250 8m and 560 8m particles produced less damage, and their action involved more plastic deformation type wear. The 304 SS had a lower abrasion resistance than the 310 SS. For the austentic and ferritic steels the subsurface deformation was larger for impact with the coarser particles. Variations in substrate hardness had no effect on the abrasive behaviour observed. On the whole, the hardest steel (mild steel in martensitic condition) showed the higher extent of damage, irrespective of particle size
Inguinal plasty and appendectomy as treatment for Amyand's hernia: case report and literature review
Amyand's hernia is described as the presence of the caecal appendix within the hernial sac of an incarcerated inguinal hernia. It was reported as an incidental finding in 1% of cases and with evidence of appendicitis in 0.1% of cases. The approach involves performing appendectomy and inguinal repair in the same surgical time, depending on the clinical scenario and the surgeon's decisions. We presented the case of a 76-year-old male patient with a diagnosis of Amyand's right inguinal hernia diagnosed during trans-operative right inguinal plasty
Impaired Motion Processing in Schizophrenia and the Attenuated Psychosis Syndrome : Etiological and Clinical Implications
The authors thank Gail Silipo, M.A. for assistance in subject recruitment, Raj Sangoi (RT)(R)(MR) and Caxia Hu, M.S., for assistance in MRI scanning and Isabel and Herb Stusser for their generous support. This research was supported by NIMH grant MH084031 (MJH) DA03383 (DCJ).Peer reviewedPostprin
In response to: Comment on “Review of Dohan Eherenfest et al. (2009) on “Classification of platelet concentrates: From pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)”
Review of dohan eherenfest et al. (2009) on “classification of platelet concentrates: from pure platelet-rich plasma (p-prp) to leucocyte- and platelet-rich fibrin (l-prf)”
This classic discusses the original publication of Dohan Eherenfest et al. on "Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)", in which the authors propose four categories of platelet concentrates depending on their leukocyte and fibrin content (P-PRP, leucocyte- and platelet-rich plasma (L-PRP), pure platelet-rich fibrin (P-PRF), and L-PRF) to group a "jungle" of products in which the term platelet-rich plasma (PRP) was used indistinctly. They were able to identify common factors such as: (1) the use of anticoagulant and immediate centrifugation of the blood after its collection, (2) most preparation techniques allowed platelet concentrate preparation within an hour, (3) the centrifugation aimed to separate the blood in layers that would allow the extraction of specific fractions, and (4) the product was activated with thrombin or calcium chloride. The reviewed manuscript has been listed among the most cited PRP articles in regenerative medicine, with more than 800 citations, driving the current scientific research and clinical practice by categorizing L-PRP and P-PRP (now, leukocyte-poor PRP). The classification has also opened the door to understanding intrinsic biological mechanisms between the platelets, leukocytes, fibrin, and growth factors, later considered for studying the proliferation and differentiation of cells in different tissues affected by PRP. Since the initial classification of platelet concentrates, several other classification systems have been proposed and published in the current literature, such as the PAW, Mishra, PLRA, DEPA, MARSPILL, etc. These classifications have identified important aspects of PRP that affect the biological composition and, ultimately, the indications and outcomes. To date, there is still a lack of standardization in sample preparation, cohort heterogeneity, and incomplete reporting of sample preparation utilized, leading to a lack of clarity and challenging researchers and clinicians
Identification of viral infections in the prostate and evaluation of their association with cancer
<p>Abstract</p> <p>Background</p> <p>Several viruses with known oncogenic potential infect prostate tissue, among these are the polyomaviruses BKV, JCV, and SV40; human papillomaviruses (HPVs), and human cytomegalovirus (HCMV) infections. Recently, the Xenotropic Murine Leukemia Virus-related gammaretrovirus (XMRV) was identified in prostate tissue with a high prevalence observed in prostate cancer (PC) patients homozygous for the glutamine variant of the RNASEL protein (462Q/Q). Association studies with the R462Q allele and non-XMRV viruses have not been reported. We assessed associations between prostate cancer, prostate viral infections, and the RNASEL 462Q allele in Mexican cancer patients and controls.</p> <p>Methods</p> <p>130 subjects (55 prostate cancer cases and 75 controls) were enrolled in the study. DNA and RNA isolated from prostate tissues were screened for the presence of viral genomes. Genotyping of the RNASEL R462Q variant was performed by Taqman method.</p> <p>Results</p> <p>R/R, R/Q, and Q/Q frequencies for R462Q were 0.62, 0.38, and 0.0 for PC cases and 0.69, 0.24, and 0.07 for controls, respectively. HPV sequences were detected in 11 (20.0%) cases and 4 (5.3%) controls. XMRV and HCMV infections were detected in one and six control samples, respectively. The risk of PC was significantly increased (Odds Ratio = 3.98; 95% CI: 1.17-13.56, p = 0.027) by infection of the prostatic tissue with HPV. BKV, JCV, and SV40 sequences were not detected in any of the tissue samples examined.</p> <p>Conclusions</p> <p>We report a positive association between PC and HPV infection. The 462Q/Q RNASEL genotype was not represented in our PC cases; thus, its interaction with prostate viral infections and cancer could not be evaluated.</p
The cell wall protein Ecm33 of Candida albicans is involved in chronological life span, morphogenesis, cell wall regeneration, stress tolerance, and host–cell interaction
Q2Q11-14Ecm33 is a glycosylphosphatidylinositol-anchored protein in the human pathogen Candida albicans. This protein is known to be involved in fungal cell wall integrity (CWI) and is also critical for normal virulence in the mouse model of hematogenously disseminated candidiasis, but its function remains unknown. In this work, several phenotypic analyses of the C. albicans ecm33/ecm33 mutant (RML2U) were performed. We observed that RML2U displays the inability of protoplast to regenerate the cell wall, activation of the CWI pathway, hypersensitivity to temperature, osmotic and oxidative stresses and a shortened chronological lifespan. During the exponential and stationary culture phases, nuclear and actin staining revealed the possible arrest of the cell cycle in RML2U cells. Interestingly, a “veil growth,” never previously described in C. albicans, was serendipitously observed under static stationary cells. The cells that formed this structure were also observed in cornmeal liquid cultures. These cells are giant, round cells, without DNA, and contain large vacuoles, similar to autophagic cells observed in other fungi. Furthermore, RML2U was phagocytozed more than the wild-type strain by macrophages at earlier time points, but the damage caused to the mouse cells was less than with the wild-type strain. Additionally, the percentage of RML2U apoptotic cells after interaction with macrophages was fewer than in the wild-type strain
Applicability of the national policy of environmental education in educational institutions
La educación ambiental es un proceso que incentiva el
desarrollo de capacidades para compatibilizar las
actividades del hombre sobre el medio ambiente, a razón
de esto, Colombia adoptó la Política Nacional de Educación
Ambiental que orienta a la implementación de Proyectos
Ambientales Escolares-PRAE. Esta investigación buscó
analizar la aplicabilidad de esta Política mediante un
comparativo entre los lineamientos de la política de
educación ambiental y el estado actual de las actividades
de las instituciones educativas (IE) enmarcadas en la
educación ambiental. Esto se realizó mediante la utilización
de la herramienta “talleres aplicados” cuya finalidad fue la
recolección primaria del grupo de estudio, entre los
resultados encontrados se evidenció un desconocimiento en
las instituciones educativas sobre los ejes temáticos y
líneas de trabajos de los PRAE, dificultades en la
divulgación del PRAE en toda la institución y poco apoyo
administrativo para la implementación respectivamente. En
general los resultados indican que las actividades
relacionadas a la temática ambiental están rezagadas a las
áreas de conocimiento de ciencias naturales y estos a su
vez no son coherentes con los PRA
Analysis of results of effective dose estimation obtained from RADAR 2017 dose assessment model for nuclear medicine procedures
EP-296
Aim/Introduction: To analyze the results of effective dose (E) estimation of the most frequent procedures using photon emitters in Nuclear Medicine, obtained from RADAR 2017 dose assessment model. To compare these results with those obtained from ICRP 128 (2015) recommendations, and to assess how using each dose assessment model can change E results.
Materials and Methods: E estimation data was collected from photon emitter procedures performed during the last year in our department, obtained from RADAR 2017 dose estimation model for age groups: = 1 year old; >1-5 years old ; >5- 10 years old, >10- 15 years old and adults. Injected activity was the one recommended by international guidelines and EANM Pediatric and Dosimetry Committees. Hybrid exams (SPECT / CT) and procedures for which there is no RADAR 2017 dosimetry estimation were excluded. Results for (E) were compared with those obtained by using ICRP 128 (2015) recommendations.
Results: With RADAR 2017 dose evaluation model we obtained a lower mean value of E on most of the procedures that were analyzed, being significantly lower for Renogram, Renal scintigraphy on >10-15 years old, Thyroid scintigraphy, Meckel’s scan and Bone Scan (0.12 to 1.16 mSv, 25% to 67%). Brain perfusion and Renal scintigraphy on ages under 10 obtained a significantly greater difference for E (0.33 to 2.85 mSv, 26% to 29%).
Conclusion: These results are an updated collection of estimated E values for photon-emitting radiopharmaceuticals commonly used in Nuclear Medicine, considering RADAR 2017 dose assessment model compared to ICRP 128) recommendations. Methodological changes on estimation lead to lower E for most of diagnostic procedures using photon emitters, this is of special interest for patients undergoing repeated ionizing radiation (dosimetry history)
High Temperature Corrosion of Inconel 600 in NaCl-KCl Molten Salts
In this work the corrosion resistance of a high content nickel alloy, Inconel 600, was investigated in mixed NaCl-KCl salts at 700, 800, and 900°C for 100 hours in static air. Investigation was carried out using electrochemical techniques such as polarization curves, rest potential measurements, linear polarization resistance, and electrochemical impedance spectroscopy. Corroded specimens were analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Electrochemical measurements showed an increased degradation rate of Inconel 600 with increasing test temperature. SEM and EDS analysis show that the damage experienced by Inconel 600 is greater than that determined by electrochemical measurements. This damage was identified as internal corrosion due to the reaction of Cl2 with the alloying elements (Cr and Fe); however, at 900°C the internal damage was minor and it was associated with the nickel content in the alloy
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