Reflections on the institutionalization process of scientific research in Latin America: the case of Cinvestav

Scientometrics - Consolidation of the scientific activity in Latin American research centers has been a matter of serious concern in recent years. In the present study we use a data set of the WoS...     

Lipids and Fatty Acids of the Gonads of Sea Urchin Diadema setosum (Echinodermata) From the Coastal Area of the Nha Trang Bay,Central Vietnam

The sea urchin Diadema setosum is edible and desirable as food by locals in central Vietnam and a promising target for potential fishing. The lipid profiles of the gonads of the sea urchin inhabiting the coastal area in Nha Trang Bay are studied for the first time. The determination of the content of the total lipids (TL), total phospholipids (PL), monoacylglycerols (MAG), diacylglycerols (DAG), triacylglycerols (TAG), cholesterol (Chol), sterol esters, and free fatty acids (FFA) is analyzed by high-performance thin layer chromatography (HPTLC); the phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and sphingomyelin (SM) are determined by high-pressure liquid chromatography (HPLC); and the fatty acid levels of TLs are identified using gas chromatography (GC). Non-polar TAG, FFA, Chol, and DAG dominated. The content of total PL is significant. PC is abundant among PL fractions, followed by PE, PI, and PS. The TLs contain a high proportion of PUFA, mainly due to arachidonic fatty acid and eicosapentanoic fatty acid. The (n−6)/(n−3) ratio is 1.68, and the atherogenic and thrombogenic indexes of D. setosum are 1.13 and 0.73. The results can be used in the development of marine bioprospecting and methodological approaches for the creation of functional substances.     

Oxidative Stress and Low-Grade Inflammation in Polycystic Ovary Syndrome: Controversies and New Insights

The pathophysiology of Polycystic Ovary Syndrome (PCOS) is quite complex and different mechanisms could contribute to hyperandrogenism and anovulation, which are the main features of the syndrome. Obesity and insulin-resistance are claimed as the principal factors contributing to the clinical presentation; in normal weight PCOS either, increased visceral adipose tissue has been described. However, their role is still debated, as debated are the biochemical markers linked to obesity per se. Oxidative stress (OS) and low-grade inflammation (LGI) have recently been a matter of researcher attention; they can influence each other in a reciprocal vicious cycle. In this review, we summarize the main mechanism of radical generation and the link with LGI. Furthermore, we discuss papers in favor or against the role of obesity as the first pathogenetic factor, and show how OS itself, on the contrary, can induce obesity and insulin resistance; in particular, the role of GH-IGF-1 axis is highlighted. Finally, the possible consequences on vitamin D synthesis and activation on the immune system are briefly discussed. This review intends to underline the key role of oxidative stress and low-grade inflammation in the physiopathology of PCOS, they can cause or worsen obesity, insulin-resistance, vitamin D deficiency, and immune dyscrasia, suggesting an inverse interaction to what is usually considered.     

Lactones in the Synthesis of Prostaglandins and Prostaglandin Analogs

In the total stereo-controlled synthesis of natural prostaglandins (PGs) and their structural analogs, a vast class of compounds and drugs, known as the lactones, are encountered in a few key steps to build the final molecule, as: δ-lactones, γ-lactones, and 1,9-, 1,11-, and 1,15-macrolactones. After the synthesis of 1,9-PGF_2α and 1,15-PGF_2α lactones, many 1,15-lactones of E₂, E₃, F₂, F₃, A₂, and A₃ were found in the marine mollusc Tethys fimbria and the quest for understanding their biological role stimulated the research on their synthesis. Then 1,9-, 1,11-, and 1,15-PG lactones of the drugs were synthesized as an alternative to the corresponding esters, and the first part of the paper describes the methods used for their synthesis. The efficient Corey procedure for the synthesis of prostaglandins uses the key δ-lactone and γ-lactone intermediates with three or four stereocenters on the cyclopentane fragment to link the PG side chains. The paper describes the most used procedures for the synthesis of the milestone δ-Corey-lactones and γ-Corey-lactones, their improvements, and some new promising methods, such as interesting, new stereo-controlled and catalyzed enantioselective reactions, and methods based on the chemical/enzymatic resolution of the compounds in different steps of the sequences. The many uses of δ-lactones not only for the synthesis of γ-lactones, but also for obtaining 9β-halogen-PGs and halogen-substituted cyclopentane intermediates, as synthons for new 9β-PG analogs and future applications, are also discussed.     

Cytotoxic Potential of a-Azepano- and 3-Amino-3,4-SeCo-Triterpenoids

Semi-synthetic triterpenoids, holding an amino substituted seven-membered A-ring (azepano-ring), which could be synthesized from triterpenic oximes through a Beckmann type rearrangement followed by a reduction of lactame fragment, are considered to be novel promising agents exhibiting anti-microbial, alpha-glucosidase, and butyrylcholinesterase inhibitory activities. In this study, in an attempt to develop new antitumor candidates, a series of A-ring azepano- and 3-amino-3,4-seco-derivatives of betulin, oleanolic, ursolic, and glycyrrhetinic acids were evaluated for their cytotoxic activity against five human cancer cell lines and non-malignant mouse fibroblasts by means of a colorimetric sulforhodamine assay. Azepanoallobetulinic acid amide derivative 11 was the most cytotoxic compound of this series but showed little selectivity between the different human tumor cell lines. Flow cytometry experiments showed compound 11 to act mainly by apoptosis (44.3%) and late apoptosis (21.4%). The compounds were further screened at the National Cancer Institute towards a panel of 60 cancer cell lines. It was found that compounds 3, 4, 7, 8, 9, 11, 15, 16, 19, and 20 showed growth inhibitory (GI₅₀) against the most sensitive cell lines at submicromolar concentrations (0.20–0.94 μM), and their cytotoxic activity (LC₅₀) was also high (1–6 μM). Derivatives 3, 8, 11, 15, and 16 demonstrated a certain selectivity profile at GI₅₀ level from 5.16 to 9.56 towards K-562, CCRF-CEM, HL-60(TB), and RPMI-8226 (Leukemia), HT29 (Colon cancer), and OVCAR-4 (Ovarian cancer) cell lines. Selectivity indexes of azepanoerythrodiol 3 at TGI level ranged from 5.93 (CNS cancer cell lines SF-539, SNB-19 and SNB-75) to 14.89 for HCT-116 (colon cancer) with SI 9.56 at GI₅₀ level for the leukemia cell line K-562. The present study highlighted the importance of A-azepano-ring in the triterpenic core for the development of novel antitumor agents, and a future aim to increase the selectivity profile will thus lie in the area of modifications of azepano-triterpenic acids at their carboxyl group.     

On the efficiency of quantization-based integration methods for building simulation

Models describing energy consumption, heating, and cooling of buildings usually impose difficulties to the numerical integration algorithms used to simulate them. Stiffness and the presence of frequent discontinuities are among the main causes of those difficulties, that become critical when the models grow in size. Quantized State Systems (QSS) methods are a family of numerical integration algorithms that can efficiently handle discontinuities and stiffness in large models. For this reason, they are promising candidates for overcoming the mentioned problems. Based on this observation, this article studies the performance of QSS methods in some systems that are relevant to the field of building simulation. The study includes a performance comparison of different QSS algorithms against state-of-the-art classic numerical solvers, showing that the former can be more than one order of magnitude faster.     

When agility meets open innovation: two approaches to manage inbound projects

Open Innovation is a leading paradigm in the current landscape, and scholars have been highly focused on defining the characteristics and capabilities that firms need to implement it successfully. This research aims to understand how organizations may implement inbound OI projects. Relying on a multiple case study approach and based on primary and secondary sources, this research highlights two main approaches: team‐centred and individual‐centred. The two approaches are discussed according to previous studies, highlighting how the first one is particularly coherent with previous research on Open Innovation, while the second one offers great insights from an Agile Project Management perspective. In particular, this research suggests how the Open Innovation literature can be enriched by considering the recent advancements in the Agile literature, valuing the individual and its autonomy to embrace external ideas from an OI perspective.