Dynamic detection of the bio-molecular interaction at the surface of plasmonic nanoarrays

Nanophysics and plasmonics have recently become fields of relevant interest in the world of research and, in particular, in biosensing and biochemistry. Nanoparticles of noble metals interact with incident light giving rise to the Localized Surface Plasmon Resonance (LSPR), a sharp peak of the extinction spectra of the nanoparticles as a result of the collective oscillation at a resonant frequency of the conduction electrons. The shape of the peak and its position strongly depend on both nano system properties, as composition, size, shape, orientation, and on the local dielectric environment. A change in the medium in which the nanoparticle is embedded is indeed detected and transduced as a distortion and shift of the peak. This mechanism is at the basis of the biosensing application of plasmonic structures, revealing binding events of molecules to the surface or extremely small variation in concentration of substances in the proximity. For this reason, LSPR plasmonic biosensors gained great popularity in a broad range of applications, in particular as diagnostic devices able to quantitatively detect biomarker molecules. MicroRNA, among the others, are biomolecules of prominent interest associated to thumoral or other kind of diseases. The aim of this project is to realize and test a sensitive, specific and label-free plasmonic nanobiosensor able to detect microRNA target molecules and to investigate the dynamics of the binding of the biomolecules on the surface of the optical transducers. To accomplish this task, Au nanoprisms arrays (NPA) are chosen as reference structure, with a LSPR wavelength around 800 nm and nanofabricated via NanoSphere Lithography (NSL) and thermal evaporation deposition. All the samples are morphologically characterized with AFM or SEM microscopy. Post-treating procedure and functionalization protocols are employed to allow the binding of the analyte molecule to be detected to the sensor, and all the functionalization signals are detected by linear optical spectroscopy in the visible or near-infrared spectral range. Static measurements are performed to control the peak shift of the sample after each functionalization step, and dynamic measurements in a microfluidic setup allow to monitor the temporal evolution of the optical signal and to reconstruct in real-time the hybridization kinetics at the surface of the plasmonic sensor. A 217nm/RIU bulk sensitivity and 50fMoles limit of detection is reached with the employed structures, indicating that both the nanofabrication and functionalization strategy are successful in the detection of analyte molecules down to low concentration limits. Of course, optimization is desirable, to push even further the sensitivity and solve challenges as for example the aspecific target binding on the sensor surface. Another purpose of the work is to extract interesting information about the dynamics of the hybridization reaction that takes place when the analyte microRNA is bound to the surface of the nanoarray. Hybridization kinetics is studied, determining the time and affinity constants characterizing the reaction. The results obtained will prove the non- ideal behaviour of the association, laying the basis for future and advanced outlook about the building of a non-Langmuir association model able to analytically describe the bi-molecular binding system

Echo Revisited: Incapacitation, Exploitation, Reverberation

The world of the past and those civilisations that preceded ours is no longer. Our poems and stories cannot comfortably stage anymore “fresche, chiare et dolci acque” like those in Francesco Petrarca’s famous poem, where they appear as a harmonious background for characters of the natural kingdom. Today, they capitulate instead to the presence of contaminated waters bearing the signs of impending death or incipient destruction. Such are our expanses. In our world, Echo, the still disdained nymph in love with prideful and haughty-hearted Narcissus, can no longer naturally inhabit a landscape of unspoiled beauty. Instead, she finds herself residing in woods and along rivers soiled with filth, darkly tinted, and increasingly subject to human dominion. To phrase things differently, in our time and day, Echo, incapacitated herself, would dwell in a waste land of incapacitation, exploitation and death

Role of autophagy in cancer cell response to nucleolar and endoplasmic reticulum stress

Eukaryotic cells are exposed to many internal and external stimuli that affect their fate. In particular, the exposure to some of these stimuli induces stress triggering a variety of stress responses aimed to re-establish cellular homeostasis. It is now established that the deregulation of stress response pathways plays a central role in cancer initiation and progression, allowing the adaptation of cells to an altered state in the new environment. Autophagy is a tightly regulated pathway which exerts “housekeeping” role in physiological processes. Recently, a growing amount of evidence highlighted the crucial role of autophagy in the regulation of integrated stress responses, including nucleolar and endoplasmic reticulum. In this review, we attempt to afford an overview of the complex role of nucleolar and endoplasmic reticulum stress-response mechanisms in the regulation of autophagy in cancer and cancer treatment

Reuse of Decommissioned Hydrocarbon Wells in Italian Oilfields by Means of a Closed-Loop Geothermal System

Geological and geophysical exploration campaigns have ascertained the coexistence of low to medium-temperature geothermal energy resources in the deepest regions of Italian sedimentary basins. As such, energy production based on the exploitation of available geothermal resources associated with disused deep oil and gas wells in Italian oilfields could represent a considerable source of renewable energy. This study used information available on Italian hydrocarbon wells and on-field temperatures to apply a simplified closed-loop coaxialWellbore Heat Exchanger (WBHE) model to three different hydrocarbon wells located in different Italian oilfields (Villafortuna-Trecate, Val d’Agri field, Gela fields). From this study, the authors have highlighted the differences in the quantity of potentially extracted thermal energy from different analysed wells. Considering the maximum extracted working fluid temperature of 100 °C and imagining a cascading exploitation mode of the heat accumulated, for Villafortuna 1 WBHE was it possible to hypothesise a multi-variant and comprehensive use of the resource. This could be done using existing infrastructure, available technologies, and current knowledge

Abandoned oil and gas wells exploitation by means of closed-loop geothermal systems: a review

In mature oilfields, decommissioned oil and gas wells with depths reaching approximately 5000-6000 metres represent good candidate structures for geothermal heat exploitation, as they can provide useful access to subsurface geothermal energy resources. Comprehending the possibility to economically harness geothermal energy by means of co-axial WBHEs is bound to the main features of the physical model, applied to estimate the amount of heat that can be gained from the borehole. Simultaneously, due to the continuous spatial variability of geological formations in oilfields, accurate and realistic estimates of the heat exchanger performances cannot be separated from a proper consideration of the thermophysical parameters of geological strata surrounding the hydrocarbon wells

Is the chemotherapy era in advanced non-small cell lung cancer really over? Maybe not yet

Lung cancer is one of the most frequently diagnosed tumors in both the male and female population. In Italy it is the leading cause of cancer deaths in men and the third in women. Although the 5-year survival rate has moderately increased in the last years, the diagnosis remains associated with a very poor prognosis. However, in the last decade significant progress has been made, also in the treatment of advanced-stage non-small cell lung cancer. The advent of targeted therapies and the recent explosion of immunotherapy seem to have limited the role of chemotherapy. But is this completely true? The aim of this editorial is to discuss some of the most controversial aspects of the therapeutic scenario in non-small cell lung cancer, with particular attention to the role that chemotherapy still play

Liver transplantation for viral hepatitis in 2015

Liver transplantation (LT) is a life-saving treatment for patients with end-stage liver disease and for patients with liver cell cancer related to liver disease. Acute and chronic liver diseases related to hepatitis viruses are between the main indications for liver transplantation. The risk of viral reinfection after transplantation is the main limiting factor in these indications. Before the availability of antiviral prophylaxis, hepatitis B virus (HBV) recurrence was universal in patients who were HBV DNA-positive before transplantation. The natural history of recurrent HBV was accelerated by immunosuppression, and it progressed rapidly to graft failure and death. Introduction of post-transplant prophylaxis with immunoglobulin alone first, and associated to antiviral drugs later, drastically reduced HBV recurrence, resulting in excellent long-term outcomes. On the contrary, recurrence of hepatitis C is the main cause of graft loss in most transplant programs. Overall, patient and graft survival after LT for hepatitis C virus (HCV)-associated cirrhosis is inferior compared with other indications. However, successful pretransplant or post transplant antiviral therapy has been associated with increased graft and overall survival. Until recently, the combination of pegylated interferon and ribavirin was the standard of care for the treatment of patients with chronic hepatitis C. Highly active antiviral compounds have been developed over the past decade, thanks to new in vitro systems to study HCV entry, replication, assembly, and release

SOURCE: a semi-automatic tool for spring-monitoring data analysis and aquifer characterisation

It has become increasingly necessary to optimise mountain groundwater resource management and comprehend resourcerecharging systems from a hydrogeological perspective to formulate adequate resource protection strategies. Analysing mountain spring behaviour and aquifer characteristics can be time-consuming, so new automated techniques and software tools are needed to estimate hydrogeological parameters and understand the exhaustion dynamics of groundwater resources. This paper introduces SOURCE, a new semi-automatic tool that automates the hydrogeological characterisation of water springs and provides proper estimations of the vulnerability index, as well as autocorrelation and cross-correlation statistical coefficients. SOURCE rapidly processed input data from the Mascognaz 1 spring (Aosta Valley) water probes and meteorological station to provide graphical outputs and values for the main hydrodynamic parameters. Having a single software package that contains all the main methods of water spring analysis could potentially reduce analysis times from a few days to a few hours