811 research outputs found
A note on the products ((m+1)(2)+1)((m+2)(2)+1) ... (n(2)+1) and ((m+1)(3)+1)((m+2)(3)+1) ... (n(3)+1)
No full textWe prove that for any positive integer m there exists a positive real number N-m such that whenever the integer n >= m neither the product P-m(n) = ((m + 1)(2) + 1) ((m + 2)(2) + 1) ... (n(2) + 1) nor the product Q(m)(n) = ((m + 1)(3) + 1)((m + 2)(3) + 1) ... (n(3) + 1) is a square
A note on the products ((m+1)(2)+1)((m+2)(2)+1) ... (n(2)+1) and ((m+1)(3)+1)((m+2)(3)+1) ... (n(3)+1)
No full textWe prove that for any positive integer m there exists a positive real number N-m such that whenever the integer n >= m neither the product P-m(n) = ((m + 1)(2) + 1) ((m + 2)(2) + 1) ... (n(2) + 1) nor the product Q(m)(n) = ((m + 1)(3) + 1)((m + 2)(3) + 1) ... (n(3) + 1) is a square
The evolving role of fetuin‐a in nonalcoholic fatty liver disease: An overview from liver to the heart
No full textNonalcoholic fatty liver disease (NAFLD) is strongly associated to the features of metabolic syndrome which can progress to cirrhosis, liver failure and hepatocellular carcinoma. How-ever, the most common cause of mortality in people with NAFLD is not liver‐related but stems from atherosclerotic cardiovascular disease (CVD). The prevalence of NAFLD is on the rise, mainly as a consequence of its close association with two major worldwide epidemics, obesity and type 2 diabetes (T2D). The exact pathogenesis of NAFLD and especially the mechanisms leading to disease progression and CVD have not been completely elucidated. Human fetuin‐A (alpha‐2‐Heremans Schmid glycoprotein), a glycoprotein produced by the liver and abundantly secreted into the circulation appears to play a role in insulin resistance, metabolic syndrome and inflammation. This review discusses the links between NAFLD and CVD by specifically focusing on fetuin‐A’s function in the pathogenesis of NAFLD and atherosclerotic CVD
Developing authentic problems through lived experiences in nature
No full textThis study's main objective is to develop a theoretical and ontological basis for experimentation in contact with the real life, oriented to physics education. Physics is built upon the observation of nature, where our experience provides opportunity to deal with science in natural environment to those learners who have background in the very basics and essentials of physics. Physics in Nature course includes visiting and camping experiences situated in nature and organizing camp with educational purposes. The course has been integrated with indoor and outdoor settings interactively and the authentic problems, which have been taken from outdoor settings, have been brought into the class without well-defined structure (Ill-structured problems). Within the period of ten years, there were plethora of events and problems that would provide sufficient material for many researchers. Because every problem is an event and has a story. The philosophical event concept of Deleuze and Guattari has been used in the events of Physics in Nature courses. Post-qualitative research methodology has been used in order to put forward how to construct the relation between physics and nature and become the main problem in the physics in nature, thereby it has been the basis of the course and our academic researc
Corrosion Behavior of Novel Titanium-Based High Entropy Alloys Designed for Medical Implants
No full textGurel, Seyma/0000-0002-3176-2388; Canadinc, Demircan/0000-0001-9961-7702This paper reports on the corrosion behavior of three TiTaHf-based high entropy alloys (HEAs) in simulated body fluid (SBF) and artificial saliva (AS) in order to assess their potential utility as implant materials. Specifically, TiTaHfNb, TiTaHfNbZr and TiTaHfMoZr HEAs were subjected to static immersion experiments in SBF and AS, and both the surfaces of the samples and the immersion fluids were thoroughly examined with the state of the art techniques. The experimental results presented herein revealed that the presence of Zr and Nb in the TiTaHf-based samples enhanced corrosion performance with reduced ion release and better surface properties, while Mo addition resulted in an inhomogeneous microstructure, leading to dendrite structures and significant amount of ion release upon immersion in both media. Furthermore, a protective passive layer formation or crystallization was present on all HEA surfaces, implying that corrosion resistance can be sustained in long-term applications. Overall, the set of findings presented herein constitute an early indication of the potential of the TiTaHf-based HEAs to be utilized as implant materials.BAGEP Award of the Science Academy; AGU-BAP [FAB-2017-77]This work was supported by the BAGEP Award of the Science Academy. B. Bal acknowledges the AGU-BAP [grant number FAB-2017-77]
Groundwater pollution and quality monitoring approaches at the European level
No full textThe paper investigates the sources and processes of groundwater contamination and their assessment within the Drivers-Pressures-State-Impact-Response (DPSIR) framework. Naturally occurring substances, trace elements, radionuclides, nutrients and salt (sodium chloride) are reviewed with emphasis on the assessment of the natural background load. Some synthetic substances are also considered, these being petroleum hydrocarbons, chlorinated aliphatics, pesticides and organic-waste contaminants. Newly emerging contaminants cannot be described within the DPSIR; therefore monitoring approaches and indicators of contamination are discussed in order to propose improved monitoring plans that combine physical, chemical and biological indicators and combine science with policy
HER-3 Expression and MEK Activation in Non-small Cell Lung Cancer
No full textAbstract BackgroundHER-3 has a role in pathogenesis and development of resistance to targeted therapies in non-small cell lung cancer (NSCLC). MethodsWe analysed tumour samples from 45 patients with adenocarcinoma of the lung. HER-3 and HER-2 expression was identified using immunohistochemistry as well as bioinformatic interrogation of The Cancer Genome Atlas (TGCA). ResultsHER-3 was highly expressed in 42.2% of cases and observed more frequently than HER-2 overexpression. ERBB3 copy number alone did not account for HER-3 overexpression. Bioinformatic analysis of TCGA demonstrated that MEK activity score (a score of downstream pathway activity and surrogate of functional HER-3 signalling) did not correlate with HER-3 ligands. EGFR pathway signalling was predominant with a significantly positive correlation of EGFR and AREG expression with MEK activity score. In the ERBB3 expressed group, ERBB3 RNA expression levels were significantly correlated with MEK activity score. ERBB3 expression level remained highly positively correlated with MEK activity after adjusting for EGFR expression. ConclusionHER-3 expression is common and it is not associated with gene amplification nor is it ligand dependent. HER-3 is an alternative pathway to EGFR activating MEK. HER-3 is a potential therapeutic target in NSCLC by virtue of frequent overexpression and functional downstream signalling.</p
Effects of early phase of preconditioning on rat testicular ischemia
No full textIntroduction: Brief episodes of ischemia followed by periods of reperfusion generate a powerful protective mechanism in cell, tissue or organ, which increase the resistance to further ischemic damage. This is known as ischemic preconditioning, and has not been investigated in testis. The present experiments were undertaken to determine whether early phase of ischemic preconditioning is evident in rat testis. Materials and Methods: Surgery was conducted under thiopental ( 60 mg/kg, intraperitoneal) anesthesia in male Wistar rats. Surgical procedures were performed through a midline incision. Group 1 was designed as a sham group. In group 2, which served as the ischemia group, the animals were subjected to unilateral testicular torsion by rotating the left testis 720degrees in a clockwise direction. Then, this testis was maintained in the torsion position by fixing with a silk suture to the scrotal wall for 90 min. In groups 3 and 4, 5 or 10 min ischemia followed by 10 min reperfusion was introduced, respectively, to induce single cycle ischemic preconditioning. In group 5, which served as the multiple cycle preconditioning group, 3 cycles of 10 min ischemia and 10 min reperfusion were applied prior to 90 min ischemia. Both ipsilateral and contralateral testes were removed from the rats at the end of the experimental periods, and tissue malondialdehyde (MDA), nitric oxide ( NO) levels, xanthine oxidase (XO), myeloperoxidase (MPO) and superoxide dismutase ( SOD) activities were measured. Both testes were also evaluated histologically, assessing interstitial edema, congestion, hemorrhages, rupture of tubules and Leydig cell proliferation. Results: 90 min ischemia produced a marked increase in MDA level in left testis. However, all ischemic preconditioning protocols used in this study did not show any significant modification in MDA, NO levels or XO, MPO and SOD activities. Histological grading scale was also similar in ischemia and preconditioning groups. Conclusion: These results suggest that there are no protective effects with ischemic preconditioning in rat testis as showed by biochemical analysis and histological examinations. Copyright (C) 2005 S. Karger AG, Basel
To compare aneuploidy rates between ICSI and IVF Cases
No full textIntroduction: Intracytoplasmic sperm injection (ICSI) currently helps many couples with male infertility. However, ICSI procedure may cause asynchronous sperm decondensation. This could introduce a risk for aneuploidy. The ICSI technique also could cause damage to the second meiotic spindle during injection and cause significantly abnormal pairing of chromosomes when compared with In vitro fertilization (IVF). In this study, we have examined whether ICSI has a higher incidence of aneuploidy when compared with IVF. Material and Methods: A retrospective study was conducted on 36 individuals. Common numbers of chromosome abnormalities were detected using fluorescent in-situ hybridization (FISH). Seven probes were used to detect chromosome X, Y, 13, 16, 18, 21, and 22. Chi-square test was used for statistical analysis and presented as odd ratios with confidence intervals. Results: The age range was 26 through 44 (mean age 35.5) for IVF and 25 through 46 (mean age 35.8) for ICSI. From the 36 egg retrievals, 57 embryos were obtained from nine individuals using IVF and 183 embryos were obtained from 27 individuals using ICSI. For the IVF group, 37 of the 57 examined embryos were abnormal (65%), whereas 128 of 183 examined embryos were abnormal for the ICSI group (69.9%). Among the 57 embryos from the IVF cases, the number of absolute abnormal chromosomes were as follows: XY chromosomes: 4 (12.9%), chromosome 13: 9 (29%), chromosome 16: 7 (22.5%), chromosome 18: 6 (19.3%), chromosome 21: 8 (25.8%), chromosome 22: 10 (32.2%). For the ICSI embryos: X and Y chromosomes: 18 (14%), chromosome 13: 34 (26.5%), chromosome 16: 23 (18%), chromosome 18: 23 (18%), chromosome 21: 26 (20.3%), chromosome 22: 31 (24.2%). The odds ratios for the difference between IVF and ICSI for each chromosome were as follows: XY chromosomes: 1.53 (0.598-3.916), chromosome 13: 0.969 (0.443-2.122), chromosome 16: 0.709 (0.307-1.639), chromosome 18: 1.650 (0.650-4.188), chromosome 21: 0.777 (0.350-1.724), chromosome 22: 0.647 (0.311-1.348). Overall no significant difference between two insemination procedures was seen 0.948 (0.678-1.324). Conclusions: As a result; ICSI does not create a significantly higher aneuploidy number when compared with IVF as examined by FISH analysis of seven chromosome pairs
Peginterferon alfa-2a alone, lamivudine alone, and the two in combination in patients with HBeAg-negative chronic hepatitis B
No full textBACKGROUND: Available treatments for hepatitis B e antigen (HBeAg)-negative chronic hepatitis B are associated with poor sustained responses. As a result, nucleoside and nucleotide analogues are typically continued indefinitely, a strategy associated with the risk of resistance and unknown long-term safety implications. METHODS: We compared the efficacy and safety of peginterferon alfa-2a (180 microg once weekly) plus placebo, peginterferon alfa-2a plus lamivudine (100 mg daily), and lamivudine alone in 177, 179, and 181 patients with HBeAg-negative chronic hepatitis B, respectively. Patients were treated for 48 weeks and followed for an additional 24 weeks. RESULTS: After 24 weeks of follow-up, the percentage of patients with normalization of alanine aminotransferase levels or hepatitis B virus (HBV) DNA levels below 20,000 copies per milliliter was significantly higher with peginterferon alfa-2a monotherapy (59 percent and 43 percent, respectively) and peginterferon alfa-2a plus lamivudine (60 percent and 44 percent) than with lamivudine monotherapy (44 percent, P=0.004 and P=0.003, respectively; and 29 percent, P=0.007 and P=0.003, respectively). Rates of sustained suppression of HBV DNA to below 400 copies per milliliter were 19 percent with peginterferon alfa-2a monotherapy, 20 percent with combination therapy, and 7 percent with lamivudine alone (P<0.001 for both comparisons with lamivudine alone). Loss of hepatitis B surface antigen occurred in 12 patients in the peginterferon groups, as compared with 0 patients in the group given lamivudine alone. Adverse events, including pyrexia, fatigue, myalgia, and headache, were less frequent with lamivudine monotherapy than with peginterferon alfa-2a monotherapy or combination therapy. CONCLUSIONS: Patients with HBeAg-negative chronic hepatitis B had significantly higher rates of response, sustained for 24 weeks after the cessation of therapy, with peginterferon alfa-2a than with lamivudine. The addition of lamivudine to peginterferon alfa-2a did not improve post-therapy response rates. Copyright 2004 Massachusetts Medical Societypublished_or_final_versio
- …
