Associated bacteria affect sexual reproduction by altering gene expression and metabolic processes in a biofilm inhabiting diatom

Diatoms are unicellular algae with a fundamental role in global biogeochemical cycles as major primary producers at the base of aquatic food webs. In recent years, chemical communication between diatoms and associated bacteria has emerged as a key factor in diatom ecology, spurred by conceptual and technological advancements to study the mechanisms underlying these interactions. Here, we use a combination of physiological, transcriptomic, and metabolomic approaches to study the influence of naturally coexisting bacteria, Maribacter sp. and Roseovarius sp., on the sexual reproduction of the biofilm inhabiting marine pennate diatom Seminavis robusta. While Maribacter sp. severely reduces the reproductive success of S. robusta cultures, Roseovarius sp. slightly enhances it. Contrary to our expectation, we demonstrate that the effect of the bacterial exudates is not caused by altered cell-cycle regulation prior to the switch to meiosis. Instead, Maribacter sp. exudates cause a reduced production of diproline, the sexual attraction pheromone of S. robusta. Transcriptomic analyses show that this is likely an indirect consequence of altered intracellular metabolic fluxes in the diatom, especially those related to amino acid biosynthesis, oxidative stress response, and biosynthesis of defense molecules. This study provides the first insights into the influence of bacteria on diatom sexual reproduction and adds a new dimension to the complexity of a still understudied phenomenon in natural diatom populations

Description of a Non-Canonical AsPt Blue Species Originating from the Aerobic Oxidation of AP-1 in Aqueous Solution

The peculiar behavior of arsenoplatin-1, ([Pt(μ-NHC(CH3)O)2ClAs(OH)2], AP-1), in aqueous solution and the progressive appearance of a characteristic and intense blue color led us to carry out a more extensive investigation to determine the nature of this elusive chemical species, which we named “AsPt blue”. A multi-technique approach was therefore implemented to describe the processes involved in the formation of AsPt blue, and some characteristic features of this intriguing species were revealed

Proliferation versus migration in platelet-derived growth factor signaling: the key role of endocytosis.

It is common knowledge that platelet-derived growth factor (PDGF) is a critical regulator of mesenchymal cell migration and proliferation. Nevertheless, these two cellular responses are mutually exclusive. To solve this apparent contradiction, we studied the behavior of NIH3T3 fibroblasts in response to increasing concentrations of PDGF. We found that there is strong cell proliferation induction only with PDGF concentrations >5 ng/ml, whereas the cell migration response arises starting from 1 ng/ml and is negligible at higher PDGF concentrations. According to these phenotypic evidences, our data indicate that cells display a differential activation of the main signaling pathways in response to PDGF as a function of the stimulation dose. At low PDGF concentrations, there is maximal activation of signaling pathways linked to cytoskeleton rearrangement needed for cell motility, whereas high PDGF concentrations activate pathways linked to mitogenesis induction. Our results suggest a mechanism by which cells switch from a migrating to a proliferating phenotype sensing the increasing gradient of PDGF. In addition, we propose that the cell decision to proliferate or migrate relies on different endocytotic routes of the PDGF receptor in response to different PDGF concentrations

Evaluation and Comparison of Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs) as Vectors to Develop Hydrochlorothiazide Effective and Safe Pediatric Oral Liquid Formulations

The aim of this study was the optimization of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) in terms of physicochemical and biopharmaceutical properties, to develop effective and stable aqueous liquid formulations of hydrochlorothiazide, suitable for paediatric therapy, overcoming its low-solubility and poor-stability problems. Based on solubility studies, Precirol® ATO5 and Transcutol® HP were used as solid and liquid lipids, respectively. The effect of different surfactants, also in different combinations and at different amounts, on particle size, homogeneity and surface-charge of nanoparticles was carefully investigated. The best formulations were selected for drug loading, and evaluated also for entrapment efficiency and release behaviour. For both SLN and NLC series, the use of Gelucire® 44/14 as surfactant rather than PluronicF68 or Tween® 80 yielded a marked particle size reduction (95–75 nm compared to around 600–400 nm), and an improvement in entrapment efficiency and drug release rate. NLC showed a better performance than SLN, reaching about 90% entrapped drug (vs. 80%) and more than 90% drug released after 300 min (vs. about 65%). All selected formulations showed good physical stability during 6-month storage at 4 °C, but a higher loss of encapsulated drug was found for SLNs (15%) than for NLCs (<5%). Moreover, all selected formulations revealed the absence of any cytotoxic effect, as assessed by a cell-viability test on Caco-2 cells and are able to pass the intestinal epithelium as suggested by Caco-2 uptake experiments

Development of a Cyclodextrin-Based Mucoadhesive-Thermosensitive In Situ Gel for Clonazepam Intranasal Delivery

A thermosensitive, mucoadhesive in-situ gel for clonazepam (CLZ) intranasal delivery was developed, which aimed to achieve prolonged in-situ residence and controlled drug release, overcoming problems associated with its oral or parenteral administration. Poloxamer was selected as a thermosensitive polymer and chitosan glutamate and sodium hyaluronate as mucoadhesive and permeation enhancer. Moreover, randomly methylated β-Cyclodextrin (RAMEB) was used to improve the low drug solubility. A screening DoE was applied for a systematic examination of the effect of varying the formulation components proportions on gelation temperature, gelation time and pH. Drug-loaded gels at different clonazepam-RAMEB concentrations were then prepared and characterized for gelation temperature, gelation time, gel strength, mucoadhesive strength, mucoadhesion time, and drug release properties. All formulations showed suitable gelation temperature (29–30.5 °C) and time (50–65 s), but the one with the highest drug-RAMEB concentration showed the best mucoadhesive strength, longest mucoadhesion time (6 h), and greatest release rate. Therefore, it was selected for cytotoxicity and permeation studies through Caco-2 cells, compared with an analogous formulation without RAMEB and a drug solution. Both gels were significantly more effective than the solution. However, RAMEB was essential not only to promote drug release, but also to reduce drug cytotoxicity and further improve its permeability

Niosomes Functionalized with a Synthetic Carbohydrate Binding Agent for Mannose-Targeted Doxorubicin Delivery

Niosomes are a potential tool for the development of active targeted drug delivery systems (DDS) for cancer therapy because of their excellent behaviour in encapsulating antitumorals and the possibility to easily functionalise their surface with targeting agents. Recently, some of us developed a synthetic carbohydrate binding agent (CBA) able to target the mannosidic residues of high-mannose-type glycans overexpressed on the surface of several cancer cell lines, promoting their apoptosis. In this article, we modified the structure of this mannose receptor to obtain an amphiphilic analogue suitable for the functionalization of doxorubicin-based niosomes. Several niosomal formulations and preparation methods were investigated deeply to finally obtain functionalized niosomes suitable for parental administration, which were stable for over six months and able to encapsulate up to 85% of doxorubicin (DOXO). In vitro studies, carried out towards triple-negative cancer cells (MDA-MB231), overexpressing high-mannose-type glycans, showed a cytotoxic activity comparable to that of DOXO but with an appreciable increment in apoptosis given by the CBA. Moreover, niosomal formulation was observed to reduce doxorubicin-induced cytotoxicity towards normal cell lines of rat cardiomyocytes (H9C2). This study is propaedeutic to further in vivo investigations that can aim to shed light on the antitumoral activity and pharmacokinetics of the developed active targeted DDS

Monitoring of foodborne pathogens in raw cow milk in Tuscany

Raw milk consumption in Italy has increased over the last few years and although raw milk is characterised by cold chain, short shelf-life and the duty of boiling before domestic consumption, it is still considered a hazard. From 2010 to 2013 a monitoring survey of raw milk sold through vending machines was carried out to investigate the occurrence of several foodborne pathogens stipulated in the national legal requirements, <em>i.e.</em> <em>Listeria monocytogenes</em>, <em>Campylobacter</em> spp., Salmonella spp., <em>Escherichia coli</em> O:157 and coagulase-positive <em>Staphylococci</em>. A total of 127 raw milk samples were collected from 19 dairy herds in Tuscany Region, Italy. In addition, the milk samples were tested for the presence and count of Yersinia genus. Results shown that only one sample was positive for non verocytotoxin- producing <em>E. coli</em> O:157, whereas a total of 38 samples (29.9%) were postive for <em>Yersinia</em> genus; of the total 39 isolated bacteria, 23.6% were <em>Y. enterocolitica</em>, 2.4% <em>Y. kristenseni</em> and 4.7% <em>Y. frederiksenii</em>. None isolate was enteropathogenic; serotypes O:5 and O:8 were found in 16.6 and 13.3% of the isolates respectively, whereas none of the serotypes tested was detected in 70% of the isolates. The most probable number method revealed a count value between 0.03 and 24 MPN/mL. Based on these data a general assurance on health safety of raw milk produced and sold in Tuscany could be assessed

Suunnittelijan suuri nimijahti : nimeämisen haasteet ja mahdollisuudet markkinointialalla

Opinnäytetyössäni kerron nimeämisen prosessista, nimen merkityksestä liiketoiminnalle ja nimeämisen perusteista. Käsittelen hyvän nimen merkitystä ja tuon esille esimerkkejä hyvistä nimistä ja nimeämistavoista. Kerron nimeämistä rajoittavista tekijöistä ja muista käytännön asioista, jotka nimeämisessä on syytä ottaa huomioon. Hyvän yritys- tai tuotenimen suunnittelua ei rajoita vain luovuus, vaan monet ikäviltä tuntuvat seikat. Nimen tulee ensinnäkin olla yksilöllinen ja rekisteröitävissä Kaupparekisteriin. Toiseksi nimellä tulee olla olemassa myös vapaa domain-nimi. Äkkiseltään nimeäjän valtaa epätoivo, ettei sopivia ja vapaita nimiä enää löydy. Osittain onkin totta, että hyvät nimet on jo varattu. Tarjoan tähän ongelmaan työssäni ratkaisuja. Nimeämisen yksi haasteista on, varsinkin luovan suunnittelijan mielestä, visuaalinen näyttävyys verrattuna suomen kielen kielioppisääntöihin. Nimen tulee mielellään noudattaa oikeinkirjoitussääntöjä ja sitä tulee voida taivuttaa ongelmitta ja sen tulee myös toimia ääneen lausuttuna. Epäselvä nimi ei toimi, koska sitä ei ymmärretä, eikä muisteta. Lisäksi ulkomaille tähdätessä, tulee varmistua ettei nimellä ole loukkaavaa merkitystä kohdemaan kielellä. Kaupallisen nimen tärkein ominaisuus on olla erottuva ja myyvä. Hyvällä nimellä on myös muita ominaisuuksia, jotka liittyvät nimen mahdollisuuteen tehdä vaikutus asiakkaisiin ja jäädä mieliin. Parhaimmat nimet ovat mitaltaan lyhyitä ja lisäksi oivaltavia. Työssäni kerron lisää nimen monista vaatimuksista ja myös mahdollisuuksista ilahduttaa vastaantulijoitaan. Nimeäminen on vaativaa työtä jopa luovien suunnittelutoimistojen ammattilaisille. Nimeämiseen tulee varata riittävästi aikaa ja tehdä se ehdottomasti useamman henkilön voimin. Hyvä nimi suunnitellaan aina valitun strategian pohjalta ja se perustuu kohderyhmän syvään ymmärtämiseen. Nimiehdokkaat kannattaa testata kohderyhmässä, jotta niiden toimivuus ja mielleyhtymät saadaan selvitettyä ennen lopullisen nimen lanseerausta. Usein lopullinen nimi on kompromissi, johon ihastutaan vasta ajan kanssa. Eikä työ pääty nimen löytämiseen. Kun nimi on valittu ja varattu, puhalletaan nimeen eloa luomalla sen ympärille tarina ja toimintaa.Naming the business correctly is an essential element in the success of the company. An appropriate name can contribute the company to become more successful, while an improper name can lead to its failure. In my thesis, I present the process of naming. I describe what the basic rules of naming are, what factors need to be taken into account, and how to proceed after having found an outstanding name. Furthermore, I give examples on functioning names and advise what kind of names should be avoided. Finding a good name takes time, and the naming process seems to be demanding even for those working in creative agencies. Naming is not only a creative process since several other aspects, e.g. spelling and declining the name, also require consideration. In global business, names which are offending in some cultures should not be used. In addition, it may seem that all the good names are already taken. The most effective names are unique without the fear of being mixed up with the names of other companies. Obtaining a valid domain name can be challenging. This thesis aims to offer solutions for that problem as well. In the process of naming, firstly, it is important to know the target audience and their values. There should be a clear view on what images the name evokes in the audience. Briefly, a name should convey the expertise, value and uniqueness of the service or product. Secondly, keeping the name short helps people to remember it without hesitation. Thirdly, finding a good name becomes easier when there are several persons participating in the process. Testing the name candidates in target audience has also proved to be especially useful. Finally, the process of naming often requires compromises. After a while, the chosen name typically functions brilliantly in its context