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PurposeThe purpose of this paper is to investigate the food and beverage automatic retail environment by analysing the impact of planograms, conceived as a visual merchandising practice and shopping time – the time spent making a purchase – as part of food consumer purchasing behaviour to further enrich the debate on the ability of companies to absorb customer knowledge.Design/methodology/approachA real-world experiment was conducted using a sample of 27,230 valid observations of consumer purchasing decision-making processes at automatic vending machines (AVMs). Data were collected by a shopper behaviour analytics system that allows for a better understanding of the AVM users' behaviour. Two sets of regressions were run to test the two hypotheses.FindingsThe experimental results demonstrated that planograms – the planned, systematic organisation of products in an AVM – positively impact food purchases. A planogram acts as a mediator in the relationship between shopping time and purchase, resulting in shorter shopping times and more purchases.Originality/valueThis work adds to the customer knowledge literature by focussing on customer behaviour in the food and beverage automated shopping environment. The shopper analytics technology adopted to collect real-time data leads to a better understanding of the purchasing behaviour of AVMs' users and provides new marketing and retail insights into AVMs' performance that retailers can use to improve their marketing strategies.

The problemIn the field of upper limb neurorehabilitation, the translation from research findings to clinical practice remains troublesome. Patients are not receiving treatments based on the best available evidence. There are certainly multiple reasons to account for this issue, including the power of habit over innovation, subjective beliefs over objective results. We need to take a step forward, by looking at most important results from randomized controlled trials, and then identify key active ingredients that determined the success of interventions. On the other hand, we need to recognize those specific categories of patients having the greatest benefit from each intervention, and why. The aim is to reach the ability to design a neurorehabilitation program based on motor learning principles with established clinical efficacy and tailored for specific patient's needs. Proposed solutionsThe objective of the present manuscript is to facilitate the translation of research findings to clinical practice. Starting from a literature review of selected neurorehabilitation approaches, for each intervention the following elements were highlighted: definition of active ingredients; identification of underlying motor learning principles and neural mechanisms of recovery; inferences from research findings; and recommendations for clinical practice. Furthermore, we included a dedicated chapter on the importance of a comprehensive assessment (objective impairments and patient's perspective) to design personalized and effective neurorehabilitation interventions. ConclusionsIt's time to reconcile research findings with clinical practice. Evidence from literature is consistently showing that neurological patients improve upper limb function, when core strategies based on motor learning principles are applied. To this end, practical take-home messages in the concluding section are provided, focusing on the importance of graded task practice, high number of repetitions, interventions tailored to patient's goals and expectations, solutions to increase and distribute therapy beyond the formal patient-therapist session, and how to integrate different interventions to maximize upper limb motor outcomes. We hope that this manuscript will serve as starting point to fill the gap between theory and practice in upper limb neurorehabilitation, and as a practical tool to leverage the positive impact of clinicians on patients' recovery.

Aim of this study was to investigate a pseudo-outbreak of Mycobacterium gordonae analyzing isolates detected from clinical and environmental samples. Mycobacterium gordonae was detected in 7 out of 497 broncho-alveolar lavage (BAL) samples after bronchoscopy procedure in patients admitted to a teaching hospital between January and April 2013. During this pseudo-outbreak clinical, epidemiological, environmental and molecular investigations were performed. None of the patients met the criteria for non-tuberculous mycobacterial (NTM) lung disease and were treated for M. gordonae lung disease. Environmental investigation revealed M. gordonae in 3 samples: in tap water and in the water supply channel of the washer disinfector. All the isolates were subjected to genotyping by pulsed-field gel electrophoresis (PFGE). The PFGE revealed that only patients' isolates presented the same band pattern but no correlation with the environmental strain was detected. Surveillance of the outbreak and the strict adherence to the reprocessing procedure and its supplies resulted afterwards in no detection of M. gordonae in clinical respiratory samples. Clinical surveillance of patients was crucial to establish the start of NTM treatment. Regular screening of tap water and endoscopic equipment should be adopted to compare the clinical strains with the environmental ones when an outbreak occurs.

During the school years 2009-2010 and 2010-2011 a total of 25 cases of Non Tuberculous Cutaneous Mycobacteriosis (NTCM) were notified in children attending the same school with a swimming pool in Rome. Environmental microbiological and epidemiological investigations (only for suspected outbreaks in 2009-2010) were conducted. We screened students with skin lesions, and environmental samples were collected from the school area and the swimming pool. During the school year 2009-10 18 cases were clinically identified among 514 primary school children (3.50%) and all cases attended the swimming pool. Only 2 out of 18 cultures were positive for Mycobacterium chelonae complex (Group III, M. abscessus). Attack Rate for swimming pool use was 13,10% (17/130), with a Relative Risk 54,70 (95% CI: 9,4 - ∞). In February 2011 additional 7 cases of cutaneous NTM among children - who attended the same primary school and swimming pool were notified to the local public health authority followed by environmental microbiological investigation. Environmental samples were positive for NTM but not for M. abscessus. Mycobacteria are not included in water-quality criteria in Italy for this reason it is important to collect evidences of NTM cases caused by these infrequent pathogens, to be able to perform rapid risk assessment and to identify the best practices in prevention and management of such a risk.

This study was performed to characterize and quantify mould and yeast isolates in fresh vegetables (FV) and ready to eat salads (RTES). During 2007, a random set of 194 samples, including 56 samples of FV and 138 samples of RTES, were analyzed for a total of 388 mycological determinations. Yeasts and moulds identification was carried out on 18/56 whole FV and 42/138 RTES. Yeasts were the predominant organisms in the FV (mean values: 6.20 log cfu g-1-8.00 log cfu g-) while moulds showed lower mean values (4.70 log cfu g-l-6.79 log cfu g-l). After processing, FV samples showed a statistically significant decreases (p-value0.001) in the contamination of fungi. Most of the species identified were found both in the FV and RTES samples. Many of moulds species isolated belong to toxigenic genera Penicillium, Stachybotrys, Phoma, Fusarium indicating a potential mycotoxin production and a potential risk for consumers.

Background: Exposure to bioaerosols may pose health risks to workers operating in the processing of Urban Solid Waste (USW). The aim of this study is to evaluate microbiological air quality within an USW selection facility.Methods: Nine sampling points in an USW selection plant situated in central-southern Italy were selected. One outdoor sampling point provided the background data. Sampling was performed on a yearly basis (2005 – 2009) upon request by the management of the selection plant. Total Mesophilic Counts (TMC), as well as fungal and Gram-negative concentrations were determined.Results: The highest viable fungal particles concentrations (medians) were found in waste delivery areas (about 20000 CFU/m3), while the lowest were found in the control rooms (485 – 967 CFU/m3). TMC (median) was highest (6116 CFU/m3) at the delivery pit, followed by the machine shop (3147 CFU/m3), where no waste processing takes place. Medians of Gram-negative bacteria are below the suggested Occupational Exposure Limit of 1000 CFU/m3, although this limit was exceeded at several single time-points in the waste delivery areas, and also in a personnel resting room. The lowest Gram-negative contamination was found in the control rooms (medians Conclusions: Some areas within a USW selection plant act as internal sources of contamination towards those areas where partially processed waste, or no waste at all, is present. Well-designed air flows, or carefullythought positioning of areas that are not directly involved in waste processing are necessary and effective in obtaining

Parkinson's disease (PD) is a chronic progressive disorder mainly affecting the motor system. PD is only partially controlled by symptomatic dopaminergic treatment. Therefore, motor rehabilitation can be used in PD to reduce complications and to train patients in the use of compensatory movement strategies. Rehabilitative practice is largely dependent on the efficiency of motor learning, i.e. the acquisition of new abilities or the adaptation of pre-existing ones. Although patients with PD are able to improve their motor performance through practice, the amount and persistence of clinical benefit are uncertain. Both ''implicit'' (procedural) and ''explicit'' (declarative) features of motor learning have been extensively investigated in patients with PD using neuropsychological testing, serial reaction time paradigms, and analysis of reaching movements. Evidence from these studies suggests an early impairment of ''explicit'' learning in PD, while ''implicit'' learning is relatively preserved. The consolidation of learned motor tasks is defective in PD and the mechanisms of motor learning seem to be independent from dopamine-replacement therapy. The knowledge of motor learning in PD is critical in designing more effective rehabilitative protocols.

Over recent years, αvβ6 and αvβ8 Arg-Gly-Asp (RGD) integrins have risen to prominence as interchangeable co-receptors for the cellular entry of herpes simplex virus-1 (HSV-1). In fact, the employment of subtype-specific integrin-neutralizing antibodies or gene-silencing siRNAs has emerged as a valuable strategy for impairing HSV infectivity. Here, we shift the focus to a more affordable pharmaceutical approach based on small RGD-containing cyclic pentapeptides. Starting from our recently developed αvβ6-preferential peptide [RGD-Chg-E]-CONH2 (1), a small library of N-methylated derivatives (2–6) was indeed synthesized in the attempt to increase its affinity toward αvβ8. Among the novel compounds, [RGD-Chg-(NMe)E]-CONH2 (6) turned out to be a potent αvβ6/αvβ8 binder and a promising inhibitor of HSV entry through an integrin-dependent mechanism. Furthermore, the renewed selectivity profile of 6 was fully rationalized by a NMR/molecular modeling combined approach, providing novel valuable hints for the design of RGD integrin ligands with the desired specificity profile.

αv β6 Integrin is an epithelial transmembrane protein that recognizes latency-associated peptide (LAP) and primarily activates transforming growth factor beta (TGF-β). It is overexpressed in carcinomas (most notably, pancreatic) and other conditions associated with αv β6 integrin-dependent TGF-β dysregulation, such as fibrosis. We have designed a trimeric Ga-68-labeled TRAP conjugate of the αv β6 -specific cyclic pentapeptide SDM17 (cyclo[RGD-Chg-E]-CONH2 ) to enhance αv β6 integrin affinity as well as target-specific in-vivo uptake. Ga-68-TRAP(SDM17)3 showed a 28-fold higher αv β6 affinity than the corresponding monomer Ga-68-NOTA-SDM17 (IC50 of 0.26 vs. 7.4 nM, respectively), a 13-fold higher IC50 -based selectivity over the related integrin αv β8 (factors of 662 vs. 49), and a threefold higher tumor uptake (2.1 vs. 0.66 %ID/g) in biodistribution experiments with H2009 tumor-bearing SCID mice. The remarkably high tumor/organ ratios (tumor-to-blood 11.2; -to-liver 8.7; -to-pancreas 29.7) enabled high-contrast tumor delineation in PET images. We conclude that Ga-68-TRAP(SDM17)3 holds promise for improved clinical PET diagnostics of carcinomas and fibrosis.

The recently reported CXCR4 antagonist 3 (Ac-Arg-Ala-[DCys-Arg-2Nal-His-Pen]-CO2H) was investigated as a molecular scaffold for a CXCR4-targeted positron emission tomography (PET) tracer. Toward this end, 3 was functionalized with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and 1,4,7-triazacyclononanetriacetic acid (NOTA). On the basis of convincing affinity data, both tracers, [68Ga]NOTA analogue ([68Ga]-5) and [68Ga]DOTA analogue ([68Ga]-4), were evaluated for PET imaging in "in vivo" models of CHO-hCXCR4 and Daudi lymphoma cells. PET imaging and biodistribution studies revealed higher CXCR4-specific tumor uptake and high tumor/background ratios for the [68Ga]NOTA analogue ([68Ga]-5) than for the [68Ga]DOTA analogue ([68Ga]-4) in both in vivo models. Moreover, [68Ga]-4 and [68Ga]-5 displayed rapid clearance and very low levels of accumulation in all nontarget tissues but the kidney. Although the high tumor/background ratios observed in the mouse xenograft model could partially derive from the hCXCR4 selectivity of [68Ga]-5, our results encourage its translation into a clinical context as a novel peptide-based tracer for imaging of CXCR4-overexpressing tumors.

Glioblastoma Multiforme (GBM) is a highly invasive primary brain tumour characterized by chemo- and radio-resistance and poor overall survival. GBM can present an aberrant functionality of p53, caused by the overexpression of the murine double minute 2 protein (MDM2) and its analogue MDM4, which may influence the response to conventional therapies. Moreover, tumour resistance/invasiveness has been recently attributed to an overexpression of the chemokine receptor CXCR4, identified as a pivotal mediator of glioma neovascularization. Notably, CXCR4 and MDM2-4 cooperate in promoting tumour invasion and progression. Although CXCR4 actively promotes MDM2 activation leading to p53 inactivation, MDM2-4 knockdown induces the downregulation of CXCR4 gene transcription. Our study aimed to assess if the CXCR4 signal blockade could enhance glioma cells' sensitivity to the inhibition of the p53-MDMs axis. Rationally designed inhibitors of MDM2/4 were combined with the CXCR4 antagonist, AMD3100, in human GBM cells and GBM stem-like cells (neurospheres), which are crucial for tumour recurrence and chemotherapy resistance. The dual MDM2/4 inhibitor RS3594 and the CXCR4 antagonist AMD3100 reduced GBM cell invasiveness and migration in single-agent treatment and mainly in combination. AMD3100 sensitized GBM cells to the antiproliferative activity of RS3594. It is noteworthy that these two compounds present synergic effects on cancer stem components: RS3594 inhibited the growth and formation of neurospheres, AMD3100 induced differentiation of neurospheres while enhancing RS3594 effectiveness preventing their proliferation/clonogenicity. These results confirm that blocking CXCR4/MDM2/4 represents a valuable strategy to reduce GBM proliferation and invasiveness, acting on the stem cell component too.

Amyotrophic Lateral Sclerosis (ALS) is a fatal disease characterized by the degeneration of upper and lower motor neurons (MNs). We find a significant reduction of the retromer complex subunit VPS35 in iPSCs-derived MNs from ALS patients, in MNs from ALS post mortem explants and in MNs from SOD1G93A mice. Being the retromer involved in trafficking of hydrolases, a pathological hallmark in ALS, we design, synthesize and characterize an array of retromer stabilizers based on bis-guanylhydrazones connected by a 1,3-phenyl ring linker. We select compound 2a as a potent and bioavailable interactor of VPS35-VPS29. Indeed, while increasing retromer stability in ALS mice, compound 2a attenuates locomotion impairment and increases MNs survival. Moreover, compound 2a increases VPS35 in iPSCs-derived MNs and shows brain bioavailability. Our results clearly suggest the retromer as a valuable druggable target in ALS., ALS is a neurodegenerative disease characterized by loss of motor neurons. Here, the authors showed that reduced levels of the VSP35 subunit in the retromer complex is a conserved ALS feature and identified a new lead compound increasing retromer stability ameliorating the disease phenotype.

Integrins play important roles in physiological and pathophysiological processes. Among the RGD-recognizing integrin subtypes, the αvβ8 receptor is emerging as an attractive target because of its involvement in various illnesses, such as autoimmune diseases, viral infections, and cancer. However, its functions have, so far, not been investigated in living subjects mainly because of the lack of a selective αvβ8 ligand. Here, we report the design and potential medical applications of a cyclic octapeptide as the first highly selective small-molecule ligand for αvβ8. Remarkably, this compound displays low nanomolar αvβ8 binding affinity and a strong discriminating power of at least 2 orders of magnitude versus other RGD-recognizing integrins. Peptide functionalization with fluorescent or radioactive labels enables the selective imaging of αvβ8-positive cells and tissues. This new probe will pave the way for detailed characterization of the distinct (patho)physiological role of this relatively unexplored integrin, providing a basis to fully exploit the potential of αvβ8 as a target for molecular diagnostics and personalized therapy regimens.

Molecule interacting with CasL 2 (MICAL2), a cytoskeleton dynamics regulator, are strongly expressed in several human cancer types, especially at the invasive front, in metastasizing cancer cells and in the neo-angiogenic vasculature. Although a plethora of data exist and stress a growing relevance of MICAL2 to human cancer, it is worth noting that only one small-molecule inhibitor, named CCG-1423 (1), is known to date. Herein, with the aim to develop novel MICAL2 inhibitors, starting from CCG-1423 (1), a small library of new compounds was synthetized and biologically evaluated on human dermal microvascular endothelial cells (HMEC-1) and on renal cell adenocarcinoma (786-O) cells. Among the novel compounds, 10 and 7 gave interesting results in terms of reduction in cell proliferation and/or motility, whereas no effects were observed in MICAL2-knocked down cells. Aside from the interesting biological activities, this work provides the first structure–activity relationships (SARs) of CCG-1423 (1), thus providing precious information for the discovery of new MICAL2 inhibitors.

The oncogene KRAS is involved in the pathogenesis of many tumors such as pancreatic, lung and colorectal cancers, thereby representing a relevant target for the treatment of these diseases. The KRAS P1 promoter contains a nuclease hypersensitive, guanine-rich sequence able to fold into a G-quadruplex motif (G4). The stabilization of this G4 structure by small molecules is emerging as a feasible approach to downregulate KRAS expression. Here, a set of novel stabilizing molecules was identified through a virtual screening campaign on the NMR structure of the 22-mer KRAS G4. The most promising hits were then submitted to structure-activity relationships studies which allowed improving their binding affinity and selectivity over double helix DNA and different G4 topologies. The best derivative (19) underwent fluorescence titration experiments and further computational studies to disclose its binding mechanism to KRAS G4. Finally, biological assays showed that this compound is capable to reduce the viability of colorectal cancer cells in which mutated KRAS acts as a driver oncogene. Thus, 19 might represent the prototype of a new class of drugs for the treatment of tumors that, expressing mutated forms of KRAS, are refractory to current therapeutic regimens.

Although triiodothyronine (T3) induces several beneficial effects on lipid metabolism, its use is hampered by toxic side-effects, such as tachycardia, arrhythmia, heart failure, bone and muscle catabolism and mood disturbances. Since the α isoform of thyroid hormone receptors (TRs) is the main cause of T3-related harmful effects, several efforts have been made to develop selective agonists of the β isoform that could induce some beneficial effects (i.e. lowering triglyceride and cholesterol levels reducing obesity and improving metabolic syndrome), while overcoming most of the adverse T3-dependent side effects. Herein, we describe the drug discovery process sustained by ADME-Toxicity analysis that led us to identify novel agonists with selectivity for the isoform TRβ and an acceptable off-target and absorption, distribution metabolism, excretion and toxicity (ADME-Tox) profile. Within the small series of compounds synthesized, derivatives 1 and 3, emerge from this analysis as “potentially safe” to be engaged in preclinical studies. In in vitro investigation proved that both compounds were able to reduce lipid accumulation in HepG2 and promote lipolysis with comparable effects to those elicited by T3, used as reference drug. Moreover, a preliminary in vivo study confirmed the apparent lack of toxicity, thus suggesting compounds 1 and 3 as new potential TRβ-selective thyromimetics.

A detailed procedure is presented for the implementation and evaluation, by Nano-Flash Method, of thermal conductivity of nanofluids with water as base fluid and at different volume concentrations of Al2O3. The main advantages of this measurement technique are short measurement times, easy sample preparation and high accuracy. The ultra-sonication technique was employed for preparing the mixture and results showed that the stability and thermal conductivity enhancements of Al2O3–H2O nanofluids are highly dependent on sonication time and the energy supplied to the fluid for its preparation. An estimation of the optimal supplied energy and time for sonication was suggested, while temperature and volumetric concentration effects on thermal conductivity are evaluated by measurements. An enhancement of thermal conductivity with respect to temperature and volumetric concentration is found, as expected. Comparisons with data from literature confirmed the validity and the suitability of the nanoflash technique applied to thermal conductivity evaluation.

Recent findings have unambiguously demonstrated that DNA G-rich sequences can adopt a G-quadruplex folding in living cells, thus further validating them as crucial targets for anticancer therapy. Herein, to identify new potent G4 binders as antitumor drug candidates, we have targeted a 24-nt G4-forming telomeric sequence employing a receptor-based virtual screening approach. Among the best candidates, in vitro binding experiments allowed identification of three novel G4 ligands. Among them, the best compound features an unprecedented binding selectivity for the human telomeric DNA G-quadruplex with no detectable binding for other G4-forming sequences present at different genomic sites. This behavior correlates with the detected ability to generate DNA damage response in tumor cells at the telomeric level and efficient antiproliferative effect on different tumor cell lines at low micromolar concentrations. © 2013 American Chemical Society.

The synthesis, characterization, and functional in vitro assay in cardiac and smooth muscle (vascular and nonvascular) of a series of 4-imidazo[2,1-b] thiazole-1,4-dihydropyridines are reported. To define the calcium blocker nature of the imidazo[2,1-b]thiazole-1,4-DHPs and their selectivity on Ca v1.2 and Cav1.3 isoforms, we performed binding studies on guinea pig atrial and ventricular membranes on intact cells expressing the cloned Cav1.2a subunit and on rat brain cortex. To get major insights into the reasons for the affinity for Cav1.2 and/or Ca v1.3, molecular modeling studies were also undertaken. Some physicochemical and pharmacokinetic properties of selected compounds were calculated and compared. All the biological data collected and reported herein allowed us to rationalize the structure-activity relationship of the 4-imidazo[2,1-b]thiazole-1,4-DHPs and to identify which of these enhanced the activity at the central level. © 2013 American Chemical Society.

Interaction between the so-called benzodiazepine receptor (BzR) and the chemically heterogeneous class of its ligands is still one of the most challenging objects of theoretical studies. In the mid-90s our group began to collaborate with Prof. Antonio Da Settimo and coworkers to a project of synthesis and biological evaluation of indolylglyoxylamides designed as BzR ligands. Herein we review our efforts in designing these compounds and in interpreting their structure-affinity relationships. Our investigations were carried out for years by adopting the pharmacophore/topological model for BzR ligands set up by Cook's group. In an attempt to rationalize some puzzling structure-affinity relationships we speculated in 1998 that our ligands interact with the BzR by assuming one of two alternative binding modes (called "A" and "B") depending on whether or not they were substituted at the 5-position of the indole nucleus. Such a model received support from a considerable amount of experimental data accumulated throughout our researches. About a decade later, docking calculations performed on a homology-built model of the α 1 BzR subtype were found in agreement with the hypothesis of mode A and mode B of binding accessible to 5-H and, respectively, 5-Cl/NO 2 indole derivatives. © 2012 Bentham Science Publishers.

An exhaustive description of the molecular recognition mechanism between a ligand and its biological target is of great value because it provides the opportunity for an exogenous control of the related process. Very often this aim can be pursued using high resolution structures of the complex in combination with inexpensive computational protocols such as docking algorithms. Unfortunately, in many other cases a number of factors, like protein flexibility or solvent effects, increase the degree of complexity of ligand/protein interaction and these standard techniques are no longer sufficient to describe the binding event. We have experienced and tested these limits in the present study in which we have developed and revealed the mechanism of binding of a new series of potent inhibitors of Adenosine Deaminase. We have first performed a large number of docking calculations, which unfortunately failed to yield reliable results due to the dynamical character of the enzyme and the complex role of the solvent. Thus, we have stepped up the computational strategy using a protocol based on metadynamics. Our approach has allowed dealing with protein motion and solvation during ligand binding and finally identifying the lowest energy binding modes of the most potent compound of the series, 4-decyl-pyrazolo[1,5- a ]pyrimidin-7-one.

Osteoarthritis (OA) is the leading cause of joint pain and disability in middle-aged and elderly patients, and is characterized by progressive loss of articular cartilage. Among the various matrix metalloproteinases (MMPs), MMP-13 is specifically expressed in the cartilage of human OA patients and is not present in normal adult cartilage. Thus, MMP-13-selective inhibitors are promising candidates in osteoarthritis therapy. Recently, we designed an N-isopropoxy-arylsulfonamide-based hydroxamate inhibitor, which showed low nanomolar activity and high selectivity for MMP-13. In parallel to further studies aiming to assess the in vivo activity of our compound, we screened the Life Chemicals database through computational docking to seek for novel scaffolds as zinc-chelating non-hydroxamate inhibitors. Experimental evaluation of 20 selected candidate compounds verified five novel leads with IC 50 in the low μM range. These newly discovered inhibitors are structurally unrelated to the ones known so far and provide useful scaffolds to develop compounds with more desirable properties. Finally, a first round of structure-based optimization on lead 1 was accomplished and led to an increase in potency of more than 5 fold. © 2011 Elsevier Masson SAS. All rights reserved.

Thumbnail image of graphical abstract A subtle change: Structural changes upon amide bond methylation improve the selectivity of the anti-angiogenic drug Cilengitide, which after N-methylation at distinct positions discriminates between the closely related pro-angiogenic integrins avß3 and avß5 (see scheme).

The widely used nonsteroidal anti-inflammatory drugs block the cyclooxygenase enzymes (COXs) and are clinically used for the treatment of inflammation, pain, and cancers. A selective inhibition of the different isoforms, particularly COX-2, is desirable, and consequently a deeper understanding of the molecular basis of selective inhibition is of great demand. Using an advanced computational technique we have simulated the full dissociation process of a highly potent and selective inhibitor, SC-558, in both COX-1 and COX-2. We have found a previously unreported alternative binding mode in COX-2 explaining the time-dependent inhibition exhibited by this class of inhibitors and consequently their long residence time inside this isoform. Our metadynamics-based approach allows us to illuminate the highly dynamical character of the ligand/protein recognition process, thus explaining a wealth of experimental data and paving the way to an innovative strategy for designing new COX inhibitors with tuned selectivity.

The synthesis, characterization, and functional in vitro assays in cardiac tissues and smooth muscle (vascular and nonvascular) of a number of 4-imidazo[2,1-b]thiazole-1,4-dihydropyridines are reported. The binding properties for the novel compounds have been investigated and the interaction with the binding site common to other aryl-dihydropyridines has been demonstrated. Interestingly, the novel 4-aryl-dihydropyridines are L-type calcium channel blockers with a peculiar pharmacological behavior. Indeed, the imidazo[2,1-b]thiazole system is found to confer to the dihydropyridine scaffold an inotropic and/or chronotropic cardiovascular activity with a high selectivity toward the nonvascular tissue. Finally, molecular modeling studies were undertaken for the most representative compounds with the aim of describing the binding properties of the new ligands at molecular level and to rationalize the found structure-activity relationship data. Due to the observed pharmacological behavior of our compounds, they might be promising agents for the treatment of specific cardiovascular pathologies such as cardiac hypertrophy and ischemia. © 2008 American Chemical Society.

NMDA receptors are glutamate-gated ion channels (iGluRs) that are involved in several important physiological functions such as neuronal development, synaptic plasticity, learning, and memory. Among iGluRs, NMDA receptors have been perhaps the most actively investigated for their role in chronic neurodegeneration such as Alzheimer's, Parkinson's, and Huntington's diseases. Recent studies have shown that the NTD of subunit NR2B modulates ion channel gating through the binding of allosteric modulators such as the prototypical compound ifenprodil. In the present paper, the construction of a three-dimensional model for the NR2B modulatory domain is described and docking calculations allow, for the first time, definition of the ifenprodil binding pose at an atomic level and fully explain all the available structure-activity relationships. Moreover, in an attempt to add further insight into the ifenprodil mechanism of action, as it is not completely clear if it binds and stabilizes an open or a closed conformation of the NR2B modulatory domain, a matter, which is fundamental for the rational design of NMDA antagonists, MD simulations followed by an MM-PBSA analysis were performed. These calculations reveal that the closed conformation of the R1-R2 domain, rather than the open, constitutes the high affinity binding site for ifenprodil and that a profound stabilization of the closed conformation upon ifenprodil binding occurs. Thus, for a rational design and/or for virtual screening experiments, the closed conformation of the R1-R2 domain should be taken into account and our 3D model can provide valuable hints for the design of NR2B-selective antagonists. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.

β-Secretase (BACE-1), a key enzyme in the etiopathogenesis and progression of Alzheimer Disease, is the focus of medicinal chemistry efforts both in the pharmaceutical industry and in academia. Despite the availability of diverse peptidomimetic BACE-1 inhibitors, nonpeptidic compounds suitable for oral delivery and transport across the blood brain barrier are in great demand. Herein, a number of active and structurally diverse inhibitors were selected and subjected to an ensemble-docking process into five BACE-1 X-ray structures. The calculated bioactive conformations of these inhibitors allowed us to build an exhaustive pharmacophore model, which captures both the common geometric and electronic features essential for enzyme inhibition. The model is intended to aid the rational design of new BACE-1 inhibitors. Furthermore, a comparison of BACE/cathepsin D X-ray structures was made to provide guidelines for the design of BACE-selective inhibitors. © 2007 Wiley-VCH Verlag GmbH& Co. KGaA.

In this paper an experimental investigation on forced convection in a compact heat exchanger made up with an aluminum foam plate of 212.5mm × 212.5mm with a thickness of 40 mm and a single array with five circular tubes is presented. The foam has a porosity of 0.93 with 20 pores per inch and the tubes in aluminum have internal and external diameters equal to 9.5 mm and 12.5 mm. The test rig consists of an open air channel and a closed water cycle and the aluminum foam plate is placed inside the channel. The performances of the compact heat exchanger are evaluated for assigned hot water mass flow rate and different hot water inlet temperatures and air mass flow rate. Results are given in terms of heat transfer rates and pressure drops as a function of air velocity and Reynolds numbers. The evaluation of dimensionless, thermal resistance, Colburn factor and Nusselt number is performed for different air mass flow rates and hot water inlet temperatures. The performance evaluation criteria is considered in terms of ratio between the heat transfer rate inside the heat exchanger and the pumping power of the air fan.

This paper deals with the characterization and modelling of water-based nanofluids containing zinc oxide (ZnO) nanoparticles in concentrations ranging between 1 and 10 wt%. Low concentrations were chosen to reduce fouling and excessive pressure drops. First of all, the stability was verified by means of an instrument, based on the dynamic light scattering (DLS) technique, measuring mean nanoparticle diameters and Zeta potential. Moreover, nanofluids pH was measured. Then, thermal conductivities and dynamic viscosities were measured, analysing their dependence on temperature and nanoparticle concentration. Thermal conductivity was measured by means of a hot disk apparatus in the temperature range between 10 and 70 degrees C, while viscosity was measured by a magnetic suspension rheometer in the same range of temperatures. Finally, the heat transfer capability of these fluids was studied measuring their heat transfer coefficients in a dedicated apparatus between 18 and 40 degrees C. Heat transfer coefficient was evaluated at different Reynolds number, in turbulent flow regime. Reynolds and Nusselt numbers were deduced by using previously measured thermal conductivity and viscosity values. Moreover, numerical simulations in two-dimensional turbulent and steady state flow were carried out. No increase in heat transfer coefficient in the temperature range between 18 and 40 degrees C was found. Comparison between experimental and numerical simulation data, in terms of wall temperature profiles, showed a good agreement.

As a continuation of our studies on 2-phenylindol-3-ylglyoxylamides as potent and selective translocator protein (TSPO) ligands, two subsets of novel derivatives, featuring hydrophilic group (OH, NH2, COOH) at the para-position of the pendent 2-phenyl ring (8-16) or different 2-aryl moieties, namely, 3-thienyl, p-biphenyl, 2-naphthyl (23-35), were synthesized and biologically evaluated, some of them showing K-i values in the subnanomolar range and the 2-naphthyl group performance being the best. The resulting SARs confirmed the key role played by interactions taking place between ligands and the lipophilic Li pocket of the TSPO binding site. Docking simulations were performed on the most potent compound of the present series (29) exploiting the recently available 3D structures of TSPO bound to its standard ligand (PK11195). Our theoretical model was fully consistent with SARs of the newly investigated as well of the previously reported 2-phenylindol-3-ylglyoxylamide derivatives.

A series of antiviral basic quinolinonyl diketo acid derivatives were developed as inhibitors of HIV-1 IN. Compounds 12d,f,i inhibited HIV-1 IN with IC50 values below 100 nM for strand transfer and showed a 2 order of magnitude selectivity over 3′-processing. These strand transfer selective inhibitors also inhibited HIV-1 RNase H with low micromolar potencies. Molecular modeling studies based on both the HIV-1 IN and RNase H catalytic core domains provided new structural insights for the future development of these compounds as dual HIV-1 IN and RNase H inhibitors. © 2014 American Chemical Society.

In this paper an experimental investigation on mixed convection in air in a heated channel partially filled with an aluminum foam is carried out. The aluminum foam layer is sets on the lower heated wall of the channel. The channel upper plate has a heat transfer toward the external ambient. The investigation allows to evaluate the effect of the aluminum foam on the mixed convection in the heated channel by wall temperature measurements and flow visualization. Results are given for heated channel without and with foam in terms of wall temperature profiles for different Reynolds number value, form 10 to 300, wall heat flux and for aluminum foam with 10 and 20 pore per inch. Lower wall temperature values are detected for the channel with foam with respect to the channel clean without foam. Foams with higher pore per inch shows lower average wall temperature values whereas the local wall temperatures showed different behaviors for the different pore per inch values. The presence of foam in heated channel determined weaker secondary motions with respect to the clean cases. The effect of the foams seems more significant for the high Reynolds number values and average Nusselt number increases with the foam presence in the heated channel.

Targeting of DNA secondary structures, such as G-quadruplexes, is now considered an appealing opportunity for drug intervention in anticancer therapy. So far, efforts made in the discovery of chemotypes able to target G-quadruplexes mainly succeeded in the identification of a number of polyaromatic compounds featuring end-stacking binding properties. Against this general trend, we were persuaded that the G-quadruplex grooves can recognize molecular entities with better drug-like and selectivity properties. From this idea, a set of small molecules was identified and the structural features responsible for G-quadruplex recognition were delineated. These compounds were demonstrated to have enhanced affinity and selectivity for the G-quadruplex over the duplex structure. Their ability to induce selective DNA damage at telomeric level and to induction of apoptosis and senescence on tumor cells is herein experimentally proven. © 2012 American Chemical Society.

Nucleic acids represent the alphabet of the cellular language and through their sequence and topology regulate vital cellular functions. In recent years, it has been found that many variations from the Watson–Crick duplex structure play key roles in many cellular processes. Examples are hairpins, cruciforms, parallel-stranded duplexes, triplexes, G-quadruplexes, and the i-motif. These structures can be formed by nucleotide sequences distributed throughout the whole human genome, their location is not random and often associated with human diseases. These complexes are formed from one to four strands, stabilized by base stacking and hydrogen bond interactions, with a variety of non-standard pairings. For instance, DNA triplexes can present G:G-C, A:A-T, C:G-C, and T:A-T pairings, with two strands in the standard Watson–Crick duplex structure (i.e. G-C and A-T) and the third one lying in the major groove of the duplex. In contrast, G-quadruplexes are four-stranded structures stabilized by stacking of two or more guanine tetrads (Figure 1). These examples highlight the structural polymorphism of DNA and suggest that other structures might exist, perhaps with specific cellular functions that are, to date, unknown. Herein, using metadynamics simulations, we have identified a stable folding intermediate of the thrombin binding aptamer (TBA) quadruplex. This intermediate is characterized by a “G-triplex” structure, having G:G:G triad planes stabilized by an array of Hoogsteen-like hydrogen-bonds (Figure 1). This kind of structure has been already hypothesized in other investigations on different DNA sequences, but never experimentally proven. Herein, for the first time, we have structurally and thermodynamically characterized this DNA structural motif, through a combination of biophysical experiments. Well-tempered metadynamics simulations have been used to study the folding of TBA, which is a 15-mer oligonucleotide (5’-dGGTTGGTGTGGTTGG-3’) organized in an anti-parallel monomolecular G-quadruplex with a chairlike structure (Figure 2a). This structure consists of two Gtetrads, able to coordinate a metal ion at the center, connected by two TT loops and a single TGT loop. Metadynamics accelerates the sampling, adding a bias on a few degrees of freedom of the system, called collective variables (CVs). In such a way, long time scale events, such as ligand/protein docking or protein/DNA folding, can be sampled in an affordable computational time and the free energy surface (FES) of the process can be computed. In the present case, the FES was calculated as a function of two CVs, the radius of gyration CV defined by the oxygen atoms of the guanines forming the G-tetrads and a second CV that counts the number of hydrogen bonds between these guanines (see Supporting Information). Looking at the FES obtained after approximately 80 ns of metadynamics simulation, three main energy minima can be identified (Figure 2b). The deepest one, basin A, corresponds to the experimental G-quadruplex structure of TBA. In the second minimum, basin B, TBA shows a partial opening of the 3’ end with residue G15

Nowadays, the molecular basis of interaction between low molecular weight compounds and biological macromolecules is the subject of numerous investigations aimed at the rational design of molecules with specific therapeutic applications. In the last decades, it has been demonstrated that DNA quadruplexes play a critical role in several biological processes both at telomeric and gene promoting levels thus providing a great stride in the discovery of ligands able to interact with such a biologically relevant DNA conformation. So far, a number of experimental and computational approaches have been successfully employed in order to identify new ligands and to characterize their binding to the DNA. The main focus of this review is the description of these methodologies, placing a particular emphasis on computational methods, isothermal titration calorimetry (ITC), mass spectrometry (MS), nuclear magnetic resonance (NMR), circular dichroism (CD) and fluorescence spectroscopies. © 2012 Bentham Science Publishers.

A series of 4-allyl/benzyl-7,8-dihydro-8-methyl/ethyl-2-[(substituted) isoxazol/pyrazol-3/5-yl]-1H-imidazo[2,1-i]purin-5(4H)-ones has been synthesized and evaluated in radioligand binding assays to determine their affinities at the human A 1, A 2A, and A 3 adenosine receptors. Efficacy at the hA 2B AR and antagonism of selected ligands at the hA 3 AR were also assessed through cAMP experiments. All of the synthesized molecules exhibited high affinity at the hA 3 AR (K i values ranging from 1.46 to 44.8 nM), as well as remarkable selectivity versus A 1, A 2A, and A 2B AR subtypes. Compound (R)-4-allyl-8-ethyl-7,8-dihydro-2-(3-methoxy-1-methyl-1H- pyrazol-5-yl)-1H-imidazo[2,1-i]purin-5(4H)-one (R-33) was found to be the most potent and selective ligand of the series (K i hA 3 = 1.46 nM, K i hA 2A/K i hA 3 > 3425; IC 50 hA 2B/K i hA 3 > 3425; K i hA 1/K i hA 3 = 1729). Molecular modeling studies were helpful in rationalizing the available structure-activity relationships along with the selectivity profiles of the new series of ligands. © 2011 American Chemical Society.

The growing amount of literature about G-quadruplex DNA clearly demonstrates that such a structure is no longer viewed as just a biophysical strangeness but it is instead being considered as an important target for the treatment of various human disorders such as cancers or venous thrombosis. In this scenario, with the aim of finding brand new molecular scaffolds able to interact with the groove of the DNA quadruplex [d(TGGGGT)] 4, we recently performed a successful structure-based virtual screening (VS) campaign. As a result, six molecules were found to be somehow groove binders. Herein, we report the results of novel NMR titration experiments of these VS-derived ligands with modified quadruplexes, namely [d(TGG BrGGT)] 4 and [d(TGGGG BrT)] 4. The novel NMR spectroscopy experiments combined with molecular modelling studies, allow for a more detailed picture of the interaction between each binder and the quadruplex DNA. Noteworthy, isothermal titration calorimetry (ITC) measurements on the above-mentioned compounds revealed that 2, 4, and 6 besides their relatively small dimensions bind the DNA quadruplex [d(TGGGGT)] 4 with higher affinity than distamycin A, to the best of our knowledge, the most potent groove binder identified thus far. © 2011 Elsevier Masson SAS. All rights reserved.

The chemokine receptor CXCR4 is a critical regulator of inflammation and immune surveillance, and it is specifically implicated in cancer metastasis and HIV-1 infection. On the basis of the observation that several of the known antagonists remarkably share a C 2 symmetry element, we constructed symmetric dimers with excellent antagonistic activity using a derivative of a cyclic pentapeptide as monomer. To optimize the binding affinity, we investigated the influence of the distance between the monomers and the pharmacophoric sites in the synthesized constructs. The affinity studies in combination with docking computations support a two-site binding model. In a final step, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was introduced as chelator for (radio-)metals, thus allowing to exploit these compounds as a new group of CXCR4-binding peptidic probes for molecular imaging and endoradiotherapeutic purposes. Both the DOTA conjugates and some of their corresponding metal complexes retain good CXCR4 affinity, and one 68Ga labeled compound was studied as PET tracer. © 2011 American Chemical Society.