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For a photovoltaic (PV) generator, knowledge of the parameters describing its equivalent circuit is fundamental to deeply study and simulate its operation in any weather conditions. In the literature, many papers propose methods to determine these parameters starting from experiments. In the most common circuit, there are five of these parameters, and they generally refer to specific weather conditions. Moreover, the dependence on irradiance and temperature is not investigated for the entire set of parameters. In fact, a few papers present some equations describing the dependence of each parameter on weather conditions, but some of their coefficients are unknown. As a consequence, this information cannot be used to predict the PV energy in any individual weather condition. This work proposes an innovative technique to assess the generated energy by PV modules starting from the knowledge of their equivalent parameters. The model is applied to a highly efficient PV generator with all-back contact, monocrystalline silicon technology, and rated power of 370 W. The effectiveness of the model is investigated by comparing its energy prediction with the value estimated by the most common model in the literature to assess PV energy. Generated energy is predicted by assuming PV power to be constant for a time interval of 1 min.

The power-wind speed curve of a Wind Turbine (WT) is measured by the manufacturer in ideal conditions, and the wind speed is detected at the entrance of the WT rotor. However, in wind power plants, this quantity is rarely available because, generally, the wind speed is measured by an anemometer behind the WT. In this case, this value is lower than the wind speed at the entrance of the WT rotor. As a result, the WT performance, evaluated using these wind speed data, may be unrealistic. Thus, their correction is performed by a technique similar to instrument calibration in which the data distribution is compared with the wind speed of the manufacturer's power curve. In this context, the present work proposes an innovative method to correctly assess the performance of WTs. In particular, it is based on the manufacturer curve, correcting the wind speeds measured behind the WTs rotor. The correction is applied to one WT (rated power =2MW) of a wind farm in Mauritania.

The reliability of photovoltaic (PV) generators is strongly affected by the performance of Direct Current/Alternating Current (DC/AC) converters, being the major source of PV underperformance. However, generally, their reliability is not investigated at component level: thus, the present work presents a reliability analysis and the repair activity for the components of full bridge DC/AC converters. In the first part of the paper, a reliability analysis using failure rates from literature is carried out for 132 inverters (AC rated power of 350 kW each) with global AC power of 46 MW in a large scale grid-connected PV plant. Then, in the second part of the work, results from literature are compared with data obtained by analyzing industrial maintenance reports in the years 2015–2017. In conclusion, the yearly energy losses involved in the downtime are quantified, as well as their availability.

Performance monitoring of horizontal-axis wind turbines is a complex task because they operate under nonstationary conditions. Furthermore, in real-world applications, there can be data quality issues because the free stream wind speed is reconstructed through a nacelle transfer function from cup anemometers measurements collected behind the rotor span. Given these matters of fact, one of the objectives of the present work is applying an innovative method for correcting the nacelle wind speed measurements, which is based on the manufacturer power curve and statistical considerations. Three operating wind turbines, having 2 MW of rated power and owned by the ENGIE Italia company, are contemplated as test cases. Operation data spanning ten years (2011–2020) are studied: actually, this work aims as well at contributing to the methods for estimating the performance decline with age of wind turbines, basing on long term SCADA data analysis. The raw and corrected wind speed measurements are fed as input to a Support Vector Regression for the power curve: by selecting appropriately the training and validation data sets, it is possible to estimate the average yearly rate of performance decline. Using the corrected wind speed, the estimate obtained in this study is compatible with the most recent findings in the literature, which indicate a -0.17% decline per year.

Recently, it has become clearer that tumor plasticity increases the chance that cancer cells could acquire new mechanisms to escape immune surveillance, become resistant to conventional drugs, and spread to distant sites.Effectively, tumor plasticity drives adaptive response of cancer cells to hypoxia and nutrient deprivation leading to stimulation of neoangionesis or tumor escape. Therefore, tumor plasticity is believed to be a great contributor in recurrence and metastatic dissemination of cancer cells. Importantly, it could be an Achilles' heel of cancer if we could identify molecular mechanisms dictating this phenotype.The reactivation of stem-like signalling pathways is considered a great determinant of tumor plasticity; in addition, a key role has been also attributed to tumor microenvironment (TME). Indeed, it has been proved that cancer cells interact with different cells in the surrounding extracellular matrix (ECM). Interestingly, well-established communication represents a potential allied in maintenance of a plastic phenotype in cancer cells supporting tumor growth and spread. An important signalling pathway mediating cancer cell-TME crosstalk is represented by the HGF/c-Met signalling.Here, we review the role of the HGF/c-Met signalling in tumor-stroma crosstalk focusing on novel findings underlying its role in tumor plasticity, immune escape, and development of adaptive mechanisms.

Recently, it has become clearer that tumor plasticity increases the chance that cancer cells could acquire new mechanisms to escape immune surveillance, become resistant to conventional drugs, and spread to distant sites.Effectively, tumor plasticity drives adaptive response of cancer cells to hypoxia and nutrient deprivation leading to stimulation of neoangionesis or tumor escape. Therefore, tumor plasticity is believed to be a great contributor in recurrence and metastatic dissemination of cancer cells. Importantly, it could be an Achilles' heel of cancer if we could identify molecular mechanisms dictating this phenotype.The reactivation of stem-like signalling pathways is considered a great determinant of tumor plasticity; in addition, a key role has been also attributed to tumor microenvironment (TME). Indeed, it has been proved that cancer cells interact with different cells in the surrounding extracellular matrix (ECM). Interestingly, well-established communication represents a potential allied in maintenance of a plastic phenotype in cancer cells supporting tumor growth and spread. An important signalling pathway mediating cancer cell-TME crosstalk is represented by the HGF/c-Met signalling.Here, we review the role of the HGF/c-Met signalling in tumor-stroma crosstalk focusing on novel findings underlying its role in tumor plasticity, immune escape, and development of adaptive mechanisms.

In cancer, the tumour suppressor gene TP53 undergoes frequent missense mutations that endow mutant p53 proteins with oncogenic properties. Until now, a universal mutant p53 gain-of-function program has not been defined. By means of multi-omics: proteome, DNA interactome (chromatin immunoprecipitation followed by sequencing) and transcriptome (RNA sequencing/microarray) analyses, we identified the proteasome machinery as a common target of p53 missense mutants. The mutant p53–proteasome axis globally affects protein homeostasis, inhibiting multiple tumour-suppressive pathways, including the anti-oncogenic KSRP–microRNA pathway. In cancer cells, p53 missense mutants cooperate with Nrf2 (NFE2L2) to activate proteasome gene transcription, resulting in resistance to the proteasome inhibitor carfilzomib. Combining the mutant p53-inactivating agent APR-246 (PRIMA-1MET) with the proteasome inhibitor carfilzomib is effective in overcoming chemoresistance in triple-negative breast cancer cells, creating a therapeutic opportunity for treatment of solid tumours and metastasis with mutant p53. Walerych et al. show that p53 missense mutants upregulate the proteasome and increase breast cancer cell resistance to proteasome inhibitors. Combined inhibition of p53 mutants and the proteasome leads to increased therapeutic efficacy.

Objectives Cognitive frailty, a condition describing the simultaneous presence of physical frailty and mild cognitive impairment, has been recently defined by an international consensus group. We estimated the predictive role of a “reversible” cognitive frailty model on incident dementia, its subtypes, and all-cause mortality in nondemented older individuals. We verified if vascular risk factors or depressive symptoms could modify this predictive role. Design Longitudinal population-based study with 3.5- and 7-year of median follow-up. Setting Eight Italian municipalities included in the Italian Longitudinal Study on Aging. Participants In 2150 older individuals from the Italian Longitudinal Study on Aging, we operationalized reversible cognitive frailty with the presence of physical frailty and pre-mild cognitive impairment subjective cognitive decline, diagnosed with a self-report measure based on item 14 of the Geriatric Depression Scale. Measurements Incidence of dementia, its subtypes, and all-cause mortality. Results Over a 3.5-year follow-up, participants with reversible cognitive frailty showed an increased risk of overall dementia [hazard ratio (HR) 2.30, 95% confidence interval (CI) 1.02–5.18], particularly vascular dementia (VaD), and all-cause mortality (HR 1.74, 95% CI 1.07–2.83). Over a 7-year follow-up, participants with reversible cognitive frailty showed an increased risk of overall dementia (HR 2.12, 95% CI 1.12–4.03), particularly VaD, and all-cause mortality (HR 1.39, 95% CI 1.03–2.00). Vascular risk factors and depressive symptoms did not have any effect modifier on the relationship between reversible cognitive frailty and incident dementia and all-cause mortality. Conclusions A model of reversible cognitive frailty was a short- and long-term predictor of all-cause mortality and overall dementia, particularly VaD. The absence of vascular risk factors and depressive symptoms did not modify the predictive role of reversible cognitive frailty on these outcomes.

AurkA overexpression was previously found in breast cancer and associated to its ability in controlling chromosome segregation during mitosis, however whether it may affect breast cancer cells, endorsed with stem properties (BCICs), is still unclear. Surprisingly, a strong correlation between AurkA expression and β-catenin localization in breast cancer tissues suggested a link between AurkA and Wnt signaling. In our study, AurkA knock-down reduced wnt3a mRNA and suppressed metastatic signature of MDA-MB-231 cells. As a consequence, the amount of BCICs and their migratory capability dramatically decreased. Conversely, wnt3a mRNA stabilization and increased CD44+/CD24low/− subpopulation was found in AurkA-overexpressing MCF7 cells. In vivo, AurkA-overexpressing primary breast cancer cells showed higher tumorigenic properties. Interestingly, we found that AurkA suppressed the expression of miR-128, inhibitor of wnt3a mRNA stabilization. Namely, miR-128 suppression realized after AurkA binding to Snail. Remarkably, a strong correlation between AurkA and miR-128 expression in breast cancer tissues confirmed our findings. This study provides novel insights into an undisclosed role for the kinase AurkA in self-renewal and migration of BCICs affecting response to cancer therapies, metastatic spread and recurrence. In addition, it suggests a new therapeutic strategy taking advantage of miR-128 to suppress AurkA-Wnt3a signaling.

Recent years have shown a progressive increase of allergic disease in the elderly population worldwide. Naturally, this phenomenon has coincided with attempts to guarantee the best possible quality of life for this age group. As a result, diseases that were previously overlooked are attracting ever greater attention. An epidemiological study of allergic manifestations in the elderly conducted in all consecutive patients referred to an Allergology Unit over a three-month period at the beginning of 2008 showed that 15% belonged to the elderly population and among these, 51.8 % were suffering from an allergic reaction to drugs. Skin manifestations, including both urticaria and eczema, accounted for 71.4% of cases but only in 13.8% of these patients was there a diagnosis of an allergic reaction made and the allergen responsible individuated. Rhinitis was present in 16.8 % of the patients and food allergy in 8 %. Certainly, age-induced modifications in the immunological system can be responsible for allergic reactions. In fact, non specific immunity components such as the production of mucus or a reduced function of the T- and IL-2 cells can induce the onset of symptoms referable to allergic disease. Further studies are ongoing to gain a better understanding of the pathogenic mechanisms that could justify the development in the elderly population of a cytokine phenotype that is more prone to develop allergic manifestations, and to assess the true incidence of respiratory, food and drug allergies in this stage of life.

Aurora-A is a centrosome-associated serine/threonine kinase that is overexpressed in multiple types of human tumors. Primarily, Aurora-A functions in centrosome maturation and mitotic spindle assembly. Overexpression of Aurora-A induces centrosome amplification and G 2 /M cell cycle progression. Recently, it was observed that overexpression of Aurora-A renders cells resistant to cisplatin (CDDP)-, etoposide-, and paclitaxel-induced apoptosis.Our results indicate that already in initial stages of cancer progression Aurora-A overexpression could have a major role in inducing supernumerary centrosomes and aneuploidy, as shown by immunohistochemistry on tissue sections from various stages of human colon cancer. Aneuploidy was also observed after Aurora-A ectopic overexpression in colon cancer cells with MIN phenotype. Silencing of Aurora-A by RNA interference in tumor cell lines triggered arrest of the cell cycle associated to apoptosis/ mitotic catastrophe. Finally, Aurora-A transcriptional silencing seems to confer cancer cells a greater sensitivity to chemotherapy by vincristine, indicating Aurora-A as a possible gene target in cancer therapy.

Cancer is a very heterogeneous disease, and biological variability adds a further level of complexity, thus limiting the ability to identify new genes involved in cancer development. Oncogenes whose expression levels control cell aggressiveness are very useful for developing cellular models that permit differential expression screenings in isogenic contexts. HMGA1 protein has this unique property because it is a master regulator in breast cancer cells that control the transition from a nontumorigenic epithelial-like phenotype toward a highly aggressive mesenchymal-like one. The proteins extracted from HMGA1-silenced and control MDA-MB-231 cells were analyzed using label-free shotgun mass spectrometry. The differentially expressed proteins were cross-referenced with DNA microarray data obtained using the same cellular model and the overlapping genes were filtered for factors linked to poor prognosis in breast cancer gene expression meta-data sets, resulting in an HMGA1 protein signature composed of 21 members (HRS, HMGA1 reduced signature). This signature had a prognostic value (overall survival, relapse-free survival, and distant metastasis-free survival) in breast cancer. qRT-PCR, Western blot, and immunohistochemistry analyses validated the link of three members of this signature (KIFC1, LRRC59, and TRIP13) with HMGA1 expression levels both in vitro and in vivo and wound healing assays demonstrated that these three proteins are involved in modulating tumor cell motility. Combining proteomic and genomic data with the aid of bioinformatic tools, our results highlight the potential involvement in neoplastic transformation of a restricted list of factors with an as-yet-unexplored role in cancer. These factors are druggable targets that could be exploited for the development of new, targeted therapeutic approaches in triple-negative breast cancer.

Breast cancer is the most common tumor and the second leading cause of cancer death among woman, mainly caused by the metastatic spread. Tumor invasiveness is due to an altered expression of adhesion molecules. Among them, semaphorins are of peculiar interest. Cancer cells can manipulate alternative splicing patterns to modulate the expression of adhesion- and motility-related molecules, also at the isoform level. In this study, combining RNA-Sequencing on MCF-7 to targeted experimental validations--in human breast cell lines and breast tumor biopsies--we identified 12 new alternative splicing transcripts in genes encoding adhesion- and motility-related molecules, including semaphorins, their receptors and co-receptors. Among them, a new SEMA3F transcript is expressed in all breast cell lines and breast cancer biopsies, and is translated into a new semaphorin 3F isoform. In silico analysis predicted that most of the new putative proteins lack functional domains, potentially missing some functions and acquiring new ones. Our findings better describe the extent of alternative splicing in breast cancer and highlight the need to further investigate adhesion- and motility-related molecules to gain insights into breast cancer progression.

The 2,3-di-O-methyl-, 2,3-di-O-ethyl-, and 2,3-di-O-acetyl- derivatives of 6-t-hexyldimethylsilyl-β- and -γ-cyclodextrins (THDMS-β- and -γ-CDs) were synthesized. The performance of columns prepared with these CD derivatives diluted in polysiloxanes with different polarity (PS-347.5, PS-086, and OV-1701) was evaluated with several series of racemates having different structures and volatilities. The results obtained with THDMS-β- and -γ-CDs were compared with those of the corresponding 6-O-t-butyldimethylsilyl-β- and -γ derivatives (TBDMS-β- and -γ-CDs) to evaluate the influence on enantioselectivity of the substituent in position 6 of the sugar units of the two cyclodextrins. Columns prepared with both series of derivatives (THDMS- and TBDMS-β- and -γ-CDs) were evaluated by analyzing a series of high-to-medium volatility racemates and of medium-to-low volatility chiral pesticides. For high-to-medium volatility racemates, the TBDMS-β-CDs are the most enantioselective, while for medium-to-low volatility racemates the THDMS-γ-CDs have a better enantioselectivity than the corresponding TBDMS-β-CDs. ©1999 John Wiley & Sons, Inc. J Micro Sep 11: 487–500, 1999

Representative examples of preparative GC isolation of pure enantiomers in amounts ranging from 0.5 to 2 mg, with thick-film wide-bore open tubular columns coated with cyclodextrin (CD) diluted in polysiloxanes, are described. Two 25 m×0.53 mm i.d. columns, coated with 3 μm of 30% 2,6-di-O-methyl-3-O-pentyl-β-CD/OV-1701 and 2 μm of 30% 2,3-di-O-acetyl-6-O-tert- butyldimethylsilyl-β-CD/PS-086 as stationary phases, were used. Methyl 3-hydroxyhexanoate, methyl 2-methylbutanoate, δ-hexalactone, δ-octalactone, and γ-decalactone (the latter from a nature-identical mango aroma), were submitted to automated micropreparative GC. Average yields of about 30% were achieved when amounts above 20 μg/μl were injected, and an enantiomeric purity above 90% was obtained.

Cyclodextrin derivatives (CDDs) are successful GC enantioselective stationary phases to evaluate essential oils through the enantiomeric composition of their optically active components. The most recent CDDs have greatly enlarged the number of separable racemates and, in many cases, it is now possible to evaluate origin and genuineness of an essential oil through several of its optically active components in a single GC run. Applications of this approach to lavender, lemon, peppermint, rose and iris oils are here described.

A method to determine residues of diflubenzuron (DFB), teflubenzuron (TFB), triflumuron (TFM) at 0.01 ppm with recoveries above 60% in apple and pear pulps for baby food is described. DFB, TFB and TFM are extracted with methanol, and cleaned up by SPE using C18 stationary phase and methanol mobile phase. Analysis of the three pesticides is by SFC-UV at 254 nm using a Diol column, and CO2 at 30 MPa and 40°C modified with acetonitrile (10%) mobile phase.

2,3- Di - O - ethyl -6- O - tert .- butyldimethylsilyl -β and −γ-cyclodextrins ( ETTBS - β - and − γ - CDs ) are proposed as stationary phases for GC separation of enantiomers. The influence of different polarity polysiloxanes (PS-347.5, PS-086, OV-1701) as diluting phase on the separation capacity of these CD derivatives was also investigated. The results of ifETTBS-β- and −γ-CDs are compared to those of if2,3-di-O-methyl-6-O-tert.-butyldimethylsilyl-β- and−γ-cyclodextrins (ifMETBS-β- and− γ - CDs ). The advantages of ETTBS - β - and − γ - CDs in terms of minimum opeative temperatures and separation capacity of the column are discussed. Each column coated with each of the new synthesized CD derivatives was evaluated by analysing a number of different racemates with different structures.

In this study, we demonstrate that constitutive activation of Raf-1 oncogenic signaling induces stabilization and accumulation of Aurora-A mitotic kinase that ultimately drives the transition from an epithelial to a highly invasive mesenchymal phenotype in estrogen receptor α-positive (ERα(+)) breast cancer cells. The transition from an epithelial- to a mesenchymal-like phenotype was characterized by reduced expression of ERα, HER-2/Neu overexpression and loss of CD24 surface receptor (CD24(-/low)). Importantly, expression of key epithelial-to-mesenchymal transition (EMT) markers and upregulation of the stemness gene SOX2 was linked to acquisition of stem cell-like properties such as the ability to form mammospheres in vitro and tumor self-renewal in vivo. Moreover, aberrant Aurora-A kinase activity induced phosphorylation and nuclear translocation of SMAD5, indicating a novel interplay between Aurora-A and SMAD5 signaling pathways in the development of EMT, stemness and ultimately tumor progression. Importantly, pharmacological and molecular inhibition of Aurora-A kinase activity restored a CD24(+) epithelial phenotype that was coupled to ERα expression, downregulation of HER-2/Neu, inhibition of EMT and impaired self-renewal ability, resulting in the suppression of distant metastases. Taken together, our findings show for the first time the causal role of Aurora-A kinase in the activation of EMT pathway responsible for the development of distant metastases in ERα(+) breast cancer cells. Moreover, this study has important translational implications because it highlights the mitotic kinase Aurora-A as a novel promising therapeutic target to selectively eliminate highly invasive cancer cells and improve the disease-free and overall survival of ERα(+) breast cancer patients resistant to conventional endocrine therapy.Oncogene advance online publication, 21 January 2013; doi:10.1038/onc.2012.628.

The results of a series of experiments concerning the GC enantioseparation of some racemates on columns coated with 2,3-di-O-acetyl-6-O-t-butyldimethylsilyl-β-cyclodextrin diluted in two different polysiloxanes (PS-086 and OV-1701) are reported. The investigation is centered on the influence of the diluting phase on the separations of the racemates investigated [δ-heptalactone, linalyl acetate, and an homologous series of cis-2-(2-alkyl-cyclopropyl)-ethanol (alkyl from ethyl to heptyl)] because one of the two polysiloxanes separated them, whereas the other did not. Column retention and efficiency characteristics were investigated as a function of the diluting phase. Retention increase (RI) and Gibbs–Helmholtz parameter (ΔR,SΔG) were determined for each of the above racemates, analyzed by different mixtures of the CDD selector with the two diluting phases. © 1995 John Wiley & Sons, Inc.

In pre vious papers, 2,6-di-O-methyl-3-O-pentyl-β-cyclodextrin (CD) was demonstrated to be successful in separating volatile compounds, while avoiding the drawbacks of 2,3,6-tri-O-methyl-O-methyl-β-CD in terms of column stability and operating temperature. Since a CD chiral selector of universal use has not yet been found, and at least two (or more) columns coated with different CD derivatives are therefore necessary for routine work, the performance of 2,6-di-O-methyl-3-O-pentyl-γ-CD, 2,6-di-O-methyl-3-O-(4-oxopentyl)-γ-CD, 2,6-di-O-pentyl-3-O-(4-oxo-pentyl)-β-CD, and 2,6-di-O-pentyl-3-O-(-4-oxo-pentyl)-γ-CD diluted in polysiloxanes for the separation of volatile compounds in aromas and essential oils will be illustrated; each column coated with each of the newly synthesized CD derivatives was evaluated by analyzing more than 150 different recemates with different structures.

Background The constant increase in the elderly population worldwide has led to a greater interest in immunologic responses during aging. Thus, special attention to allergic diseases in elderly people has begun to emerge, but little is known about the effect and features of allergic rhinitis in elderly people. Objective To evaluate the clinical and cytologic characteristics of respiratory allergy and its impact on the quality of life in elderly people. Methods Elderly patients with rhinitis referred to our allergy unit during a 3-month period underwent clinical evaluation and responded to the Rhinasthma Questionnaire. All patients also underwent skin prick testing, measurement of total IgE level, and nasal cytologic analysis. The data were compared with a control group of young adults. Results Fifty-four patients older than 65 years (mean age, 69.3 years) and 89 young adults (mean age, 26.3 years) with allergic rhinitis were studied. The elderly patients had a less positive family history of atopy ( P =.02) and had rhinitis plus conjunctivitis more frequently ( P =.002) than young adults, whereas the difference between groups in total IgE level was not statistically significant. On nasal cytologic analysis, the differential count of inflammatory cells did not differ between groups, but in the elderly patients the epithelial-goblet cell ratio was decreased. The quality of life in elderly people was more impaired than in young adults ( P =.01). Conclusion In elderly people with allergic rhinitis, the clinical characteristics are different and quality of life is more heavily impaired compared with young adults.

The ratio of the responses of two different specific detectors to a single compound has, when used in conjunction with the compound's retention index, been investigated as an identification criterion for the compound. The ECD:NPD and ECD:FPD response ratios have been used for the identification of some pesticides. Analyses were performed with a single column – dual parallel detection – personal computer system. The reliability of the detector response ratio (DRR) was demonstrated by the consistency of detector response with time, and the influence of the quantity of analyte and of the chromatographic operating conditions. These factors were selected in the expectation that the technique could be used for routine trace analysis.

In the GC separation of volatile racemates, cyclodextirin (CD) derivatives may be used either as such or diluted in polysiloxane. If diluting phases with different polarity are used, different interactions and as a consequence a different retention of each component in a complex mixture are produced. The combination of the retention indices from columns coated with a CD derivative diluted in different polysiloxane phases makes it possible to locate and to identify unambigously the enantiomers of an optically active compound in a complex mixture and hence from their areas to determine directly the enantiomeric excess (e.e.). Some examples in the fields of essential oils and aromas illustrate the abilities of 2,6-di-O-methyl-3-O-pentyl-β-CD diluted with different phases (PS-347.5, PS-086, OV-1701 and OV-1701-OH) to evaluate the e.e. of one or more optically active compounds in a complex mixture.

A simple method is described for determining trifluralin and linuron in carrots and their pulp. Samples are extracted with hexane-ethyl ether (1+1), cleaned up with a disposable Florisil cartridge, and eluted first with hexane-ethyl ether (99 + 1) (for trifluralin), and then with hexane-ethyl ether (3 + 7) (for linuron). Trifluralin is then analyzed by electron capture gas chromatography (GC/ECD), and linuron by GC/ECD and liquid chromatography with ultraviolet detection (LC/UV). Recoveries were determined by spiking untreated carrot and carrot pulp homogenates with trifluralin and linuron at 0.04, 0.16, and 0.32 μg/g. Six determinations were performed at each level for both compounds. GC/ECD average recoveries were 87.1% for trifluralin and 93.6% for linuron in carrots and 89.9% for trifluralin and 94.2% for linuron in carrot pulp. LC/UV recoveries for linuron were 91.5% for carrots and 92.8% for carrot pulp.

As a continuation of previous studies on the use of cyclodextrin derivatives (CD) for the separation of volatile compounds by capillary GC, the influence of diluting phases other than OV-1701 or OV-1701-OH has been investigated. 2,6-Di-O-methyl-3-O-pentyl-β-cyclodextrin (2,6-DiMe-3-Pe-β-CD) was taken as the reference CD derivative, because of the large number of volatile racemates it is able to separate; OV-1701 or OV-1701-OH was chosen as the reference diluting phase. The performance of a column coated with a 0.15 μm film of 10 % 2,6-DiMe-3-Pe-β-CD in OV-1701 was compared with that of analogous columns coated with films of the same thickness containing the same percentage of the CD derivative diluted with stationary phases of different polarity, i.e. PS-086, PS-347.5, and OV-225. Resolution values and separation factors of thirty racemates were used to evaluate the effect of different diluting phases on column performance.

Development of chromosomal instability (CIN) and consequent phenotypic heterogeneity represent common events during breast cancer progression. Breast carcinomas harboring extensive chromosomal aberrations display a more aggressive behavior characterized by chemoresistance and the propensity to give rise to distant metastases. The tumor suppressor p53 plays a key role in the maintenance of chromosomal stability and tissue homeostasis through activation of cell cycle checkpoints following DNA damage and control of centrosome duplication that ensures equal chromosome segregation during cell division. Furthermore, p53 suppresses CD44 expression and the acquisition of stem cell-like properties responsible for epithelial to mesenchymal transition (EMT) and metastasis. In this study we employed MCF-7 breast cancer cells with endogenous wild-type p53, an engineered MCF-7 variant (vMCF-7(DNP53)) overexpressing a dominant negative p53val135 mutant, and cells re-cultured from vMCF-7(DNP53) tumor xenografts. We carried out an integrative transcriptome and cytogenetic analysis to characterize the mechanistic linkage between loss of p53 function, EMT and consequent establishment of invasive gene signatures during breast cancer progression. We demonstrate that abrogation of p53 function drives the early transcriptome changes responsible for cell proliferation, EMT and survival, while further transcriptome changes that occur during in vivo tumor progression are mechanistically linked to the development of CIN leading to a more invasive and metastatic breast cancer phenotype. Here we identified distinct novel non-canonical transcriptome networks involved in cell proliferation, EMT, chemoresistance and invasion that arise following abrogation of p53 function in vitro and development of CIN in vivo. These studies also have important translational implications since some of the nodal genes identified here are 'druggable' making them appropriate molecular targets for the treatment of breast carcinomas displaying mutant p53, EMT, CIN and high metastatic potential.

This paper describes an evaluation of the chromatographic performance of columns coated with amorphous cyclodextrin (CD) derivatives, in particular 2,3,6-tripentyl-β-CD (2,3,6-TriPe-β-CD), 2,6-dipentyl-3-methyl-β-CD (2,6-DiPe-3-Me-β-CD), and 2,6-dimethyl-3-pentyl-β-CD (2,6-DiMe-3-Pe-β-CD), all diluted in polysiloxane (OV-1701 or OV-1701-OH), for the separation of the enantiomers of volatile compounds. 2,6-DiMe-3-Pe-β-CD in OV-1701 offers performance comparable with (or better than) that of the other two CDs, and without their drawbacks (inconsistency of results, as described previously). This article compares the separating ability of 2,6-DiMe-3-Pe-β-CD and 2,3,6-TriMe-β-CD, and describes the influence of the CD derivative to polysiloxane ratio, the minimum operating temperatures of the columns, and the reproducibility and consistency of performance of columns coated with the former CD derivative diluted in polysiloxane.

This paper reports the chromatographic performance of columns coated with 2,3,6-trimethyl-α-, β-, and γ-cyclodextrins (2,3,6-TriMe-α,- β-, and γ-CD) and their derivatives 2,6-dimethyl-3-trifluoroacetyl-α-, β-, and γ-cyclodextrins (2,6-DiMe-3-TFA-α-, β-, and γ-CD), all six diluted in polysiloxane, for the separation of the enantiomers of volatile compounds. The influence of column length and film thickness on separation is reported. Phenomena related to reproducibility and consistency, over a period of time, of columns prepared with these CD derivatives are also discussed, and a possible solution to some drawbacks reported here is proposed.

In a previous paper we described the possibilities of cold on-column – sample split injection achieved by means of an inexpensive and simple three way press-fit device [1]. The same arrangement is proposed here for cold on-column – solvent split injection in which specific elimination of the solvent, without loss of any other sample components, is achieved by opening the splitting tube (or better, in this case, the early solvent vapor exit) during solvent elution, and then closing it during elution of the sample's other components. Discrimination between solvent and other sample components is achieved by means of a retention gap, a retaining precolumn, and an early vapor exit. The technique enables both selective enrichment of a sample, in order to record satisfactory mass and infrared spectra of minor components, and injection of large volumes (up to 100 μl) of dilute solutions which cannot be concentrated because of component volatility. Details of the assembly and tuning the system are given, together with some examples.

The gas chromatographic performance of differently derivatized α-, β-, and γ-cyclodextrins in the separation of racemic mixtures of volatiles is investigated. The performances of 2,3,6-permethylated α-, β-, and γ;-cyclodextrins and 2,6-dimethyl-3-trifluoro-acetyl α-, β-, and γ-cyclodextrins mixed with different ratios of OV-1701 or OV-1701-OH terminated were tested with racemates with widely differing structures. The influence of the percentage of cyclodextrins in polysiloxane, of film thickness of the stationary phase, of the length of the column, of column conditioning, and of the operating temperatures in the separations of different racemates has been evaluated.

Background Aneuploidy is a hallmark of most human cancers that arises as a consequence of chromosomal instability and it is frequently associated with centrosome amplification. Functional inactivation of the Retinoblastoma protein (pRb) has been indicated as a cause promoting chromosomal instability as well centrosome amplification. However, the underlying molecular mechanism still remains to be clarified. Results Here we show that pRb depletion both in wild type and p53 knockout HCT116 cells was associated with the presence of multipolar spindles, anaphase bridges, lagging chromosomes and micronuclei harbouring whole chromosomes. In addition aneuploidy caused by pRb acute loss was not affected by p53 loss. Quantitative real-time RT-PCR showed that pRB depletion altered expression of genes involved in centrosome duplication, kinetochore assembly and in the Spindle Assembly Checkpoint (SAC). However, despite MAD2 up-regulation pRb-depleted cells seemed to have a functional SAC since they arrested in mitosis after treatments with mitotic poisons. Moreover pRb-depleted HCT116 cells showed BRCA1 overexpression that seemed responsible for MAD2 up-regulation. Post-transcriptional silencing of CENPA by RNA interference, resulting in CENP-A protein levels similar to those present in control cells greatly reduced aneuploid cell numbers in pRb-depleted cells. Conclusion Altogether our findings indicate a novel aspect of pRb acute loss that promotes aneuploidy mainly by inducing CENPA overexpression that in turn might induce micronuclei by affecting the correct attachment of spindle microtubules to kinetochores.

BACKGROUND: Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB) participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA) specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. RESULTS: Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC) the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. CONCLUSION: Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger chromosome segregation errors, are responsible for aneuploidy in primary human fibroblasts where pRb is acutely depleted. Background Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB) participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA) specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. Results Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC) the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. Conclusion Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger chromosome segregation errors, are responsible for aneuploidy in primary human fibroblasts where pRb is acutely depleted.

The lipophilic constituents of ‘companion canals’ and vittae co-occurring in fruits of Heracleum sphondylium L. subsp. sphondylium were investigated by microdissection and subsequent analysis by capillary gas chromatography and capillary gas chromatography-mass spectrometry. The chemical composition of the two different types of secretory structures present in the fruits is different The canals, present in all of the aerial vegetative plant parts and in the fruits, are characterized by mono- and sesquiterpenoids, while the vittae, peculiar to the fruits, contain fatty acid aliphatic esters and furocoumarins.

BackgroundIncorrect segregation of whole chromosomes or parts of chromosome leads to aneuploidy commonly observed in cancer. The correct centrosome duplication, assuring assembly of a bipolar mitotic spindle, is essential for chromosome segregation fidelity and preventing aneuploidy. Alteration of p53 and pRb functions by expression of HPV16-E6 and E7 oncoproteins has been associated with centrosome amplification. However, these last findings could be the result of targeting cellular proteins in addition to pRb by HPV16-E7 oncoprotein. To get a more detailed picture on the role of pRb in chromosomal instability and centrosome amplification, we analyzed the effects of the acute loss of retinoblastoma gene function in primary conditionalRbdeficient mouse embryonic fibroblasts (MEFs). Moreover, since pRb is a transcriptional repressor, microarray analysis was done on pRb-competent and pRb-deficient MEFs to evaluate changes in expression of genes for centrosome homeostasis and for correct mitosis.ResultsAcute loss of pRb induces centrosome amplification and aneuploidy in the vast majority of cells analyzed. A time course analysis shows a decrease of cells with amplified centrosomes after 40 days from the adenoviral infection. At this time only 12% of cells still show amplified centrosomes. Interestingly, cells with pRb constitutive loss show a similar percentage of cells with amplified centrosomes. DNA-Chip analyses in MEFs wt (mock infected) and pRb depleted (Ad-Cre infected) cells reveal differential expression of genes controlling both centrosome duplication and mitotic progression.ConclusionOur findings suggest a direct link between pRb status, centrosome amplification and chromosomal instability, and define specific mitotic genes as targets whose gene expression has to be altered to achieve or maintain aneuploidy.

Alterations in the number and/or morphology of centrosomes are frequently observed in human tumours. However, it is still debated if a direct link between supernumerary centrosomes and tumorigenesis exists and if centrosome amplification could directly cause aneuploidy. Here, we report that hydroxyurea treatment induced centrosome amplification in both human fibroblasts expressing the HPV16 -E6-E7 oncoproteins, which act principally by targeting p53 and pRB, respectively, and in conditional pRB deficient mouse fibroblasts. Following hydroxyurea removal both normal and p53 deficient human fibroblasts arrested. On the contrary pRB deficient fibroblasts entered the cell cycle generating aneuploid cells. Also the majority of conditional Rb deficient MEFs showed supernumerary centrosomes and aneuploid cells which increased over time. Finally, our results suggest that pRB dysfunction both in human and murine fibroblasts transiently arrested in G1/S by hydroxyurea allows centrosomes amplification, in the absence of DNA synthesis, that in turn could drive aneuploidy.

Lipofilling is becoming part of the breast reshaping after quadrantectomy or mastectomy in breast cancer patients, but there are open questions of its safety.

This article reviews papers published over the period 1995-1998 dealing with the application of cyclodextrin derivatives (CDs) as chiral selector for direct enantiomer GC separation of volatile optically active components in the essential oil, extract, flavour and aroma fields. For each application, the racemate analysed, the CD employed as chiral selector and the matrix investigated are reported. The applications are grouped by analytical technique employed: capillary gas chromatography and capillary gas chromatography-mass spectrometry (GC and GC-MS); two-dimensional gas chromatography (GC x GC); capillary gas chromatography-isotope ratio-mass spectrometry (GC-IRMS); liquid chromatography-capillary gas chromatography (LC-GC).