Portrait of Cancer Stem Cells on Colorectal Cancer: Molecular Biomarkers,Signaling Pathways and miRNAome

Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies.     

Measuring institutional research productivity for the life sciences: the importance of accounting for the order of authors in the byline

Accurate measurement of institutional research productivity should account for the real contribution of the research staff to the output produced in collaboration with other organizations. In the framework of bibliometric measurement, this implies accounting for both the number of co-authors and each individual’s real contribution to scientific publications. Common practice in the life sciences is to indicate such contribution through the order of author names in the byline. In this work, we measure the distortion introduced to university-level bibliometric productivity rankings when the number of co-authors or their position in the byline is ignored. The field of observation consists of all Italian universities active in the life sciences (Biology and Medicine). The analysis is based on the research output of the university staff over the period 2004–2008. Based on the results, we recommend against the use of bibliometric indicators that ignore co-authorship and real contribution of each author to research outputs.     

Relaxor behavior in (Ba1−3x/2Bix)(ZryTi1−y)O3 ceramics

New ferroelectric ceramics Bi-BZT of ABO₃ perovskite type were synthesized in the (Ba_1−3x/2Bi_x)(Zr_yTi_1−y)O₃ system by solid state reaction route. The effect of the substitution of barium by bismuth in the A cationic site on structural and dielectric properties was investigated. The dielectric constant was studied in the temperature range from 20 K to 320 K at frequencies ranging from 0.2 to 100 kHz. A clear relaxor behavior was observed for samples with x ≥ 0.075 and y = 0.1. In this case the value of the relaxation parameter γ ≈ 2 estimated from the linear fit of the modified Curie–Weiss law, indicates the relaxor nature of the Bi-BZT ceramics. The dielectric relaxation rate follows Vogel–Fulcher relation with an activation energy of 0.26 eV and 0.27 eV, an attempt frequency f₀ = 3.4 × 10¹² Hz and 5.7 × 10¹² Hz and a static freezing temperature T_VF = 98 K and 94 K respectively for x = 0.075 and x = 0.1.     

The relationship between scientists’ research performance and the degree of internationalization of their research

Policy makers, at various levels of governance, generally encourage the development of research collaboration. However the underlying determinants of collaboration are not completely clear. In particular, the literature lacks studies that, taking the individual researcher as the unit of analysis, attempt to understand if and to what extent the researcher’s scientific performance might impact on his/her degree of collaboration with foreign colleagues. The current work examines the international collaborations of Italian university researchers for the period 2001–2005, and puts them in relation to each individual’s research performance. The results of the investigation, which assumes co-authorship as proxy of research collaboration, show that both research productivity and average quality of output have positive effects on the degree of international collaboration achieved by a scientist.     

Gender differences in research productivity: A bibliometric analysis of the Italian academic system

The literature dedicated to the analysis of the difference in research productivity between the sexes tends to agree in indicating better performance for men. Through bibliometric examination of the entire population of research personnel working in the scientific-technological disciplines of Italian university system, this study confirms the presence of significant differences in productivity between men and women. The differences are, however, smaller than reported in a large part of the literature, confirming an ongoing tendency towards decline, and are also seen as more noticeable for quantitative performance indicators than other indicators. The gap between the sexes shows significant sectorial differences. In spite of the generally better performance of men, there are scientific sectors in which the performance of women does not prove to be inferior.     

Peer review research assessment: a sensitivity analysis of performance rankings to the share of research product evaluated

In national research assessment exercises that take the peer review approach, research organizations are evaluated on the basis of a subset of their scientific production. The dimension of the subset varies from nation to nation but is typically set as a proportional function of the number of researchers employed at each research organization. However, scientific fertility varies from discipline to discipline, meaning that the representativeness of such a subset also varies according to discipline. The rankings resulting from the assessments could be quite sensitive to the size of the share of articles selected for evaluation. The current work examines this issue, developing empirical evidence of variations in ranking due changes in the dimension of the subset of products evaluated. The field of observation is represented by the scientific production from the hard sciences of the entire Italian university system, from 2001 to 2003.     

A TRL-Like Calibration for Tunable Interdigitated BST Varactors

We report on a de-embedding technique for measuring the reflection coefficients of comblike capacitors patterned on barium-strontium-titanate (BST) ferroelectric films. The technique is derived from the thru-reflect-line calibration technique and is combined with conformal mapping to retrieve the complex permittivity of BST thin films. The accuracy of the method is demonstrated over a broad frequency for 0.3-mum-thick Ba_xSr_1-xTiO₃, with x = 0.5, in a paraelectric state, grown by a sol-gel technique. The samples are characterized up to 35 GHz and exhibit a constant permittivity of 245 plusmn 12%, which is in good agreement with the values deduced from propagation wave constants of BST transmission lines.     

Monitoring the oxidative modification of lipoprotein(a) by capillary zone electrophoresis

Lipoprotein(a) [Lp(a)] is a recognized risk factor for atherosclerotic cardiovascular disease. It is made of a lipoprotein particle containing apoB100 linked by a single disulfide bridge to apolipoprotein(a), a glycosylated protein with a variable mass. Some authors suggest that oxidative modification could explain the contribution of Lp(a) in the development of atheromatous lesions in a comparable way to low‐density lipoproteins (LDL). Recently, the use of capillary electrophoresis to measure the variations in the relative electrophoretic mobility (REM) of LDL subjected to copper oxidation has been proposed. The aim of this work is to employ this method also to monitor the copper‐induced oxidative modification of Lp(a). Migration of Lp(a) was monitored by absorption at 200 nm in a 50 mmol/L tricine, 100 mmol/L methylglucamine, pH 9.7 run buffer. Contrary to the conventional slab gel methods, our procedure provides a rapid and reproducible means to measure the electrophoretic mobility of Lp(a) (migration time <10 min with a CV% <0.5).     

Tunability of ferroelectric varactors up to 60 GHz

A TRL-multiline de-embedding technique for the determination of the electrical parameters of interdigitated varactors over a broad centimetre-millimetre band is proposed. The method is applied to voltage- controlled ferroelectric (BaSrTiO₃) varactors, which exhibit almost constant frequency dependence of the capacitance (epsiv_r~300) from 10 to 60 GHz. The capacitance ratio is ~2 for a 30 V bias offset, and the quality factor is of the order 10 at 30 V.