Detection of Angiogenic Growth Factor by Microcantilever Biosensors

2009/2010To reach new and relevant insights in biomolecular sciences, new tools for fine and precise measurement are needed. Nowadays advances in the field of micro-electro-mechanical systems (MEMS) offer unique opportunities in the design of ultrasensitive analytical devices to support the molecular sensing investigations. Among them Microcantilever (MC) biosensors are label-free platforms that combine a biologically sensitive with a physical transducer in order to selectively and quantitatively detect the presence of specific compounds in a given external environment. Since they can be operated either as nanomechanical resonator or as surface stress sensor, MCs - activated with DNA probes or antibodies for molecular recognition - enable the measurement of mass with extraordinary sensitivity. In particular, the development of mass detector biosensor based on MC systems would permit to shift from qualitative data to quantitative measurements of key molecules involved in physiological processes. This can lead crucial informations to characterize complex mechanisms such as angiogenesis and tumor progression and to the quantification of small amounts of cancer markers, such as Angiopoietin-1 (ANG-1), and their modulation during the early stages of tumor development.XXIII Ciclo197

Optically Tunable Diffraction Efficiency in Reflection Grating Written in Photomobile Polymers

In this work, we report the fabrication and optical characterization of a one-dimensional reflection holographic volume phase grating recorded in a recently developed holographic photomobile composite polymer mixture. The reflection grating recorded on the photomobile material was a periodic one-dimensional arrangement of hard polymeric walls and viscous regions. The reflection notch was located in the near-infrared region of the electromagnetic spectrum. The transmission efficiency of the grating was modulated by an external CW laser light source operating at λ = 532 nm. The transmission efficiency increased with the increase in the power of the external laser source, and in the range of the used power values, the phenomenon was completely reversible. At the highest power levels, a 48% increase in the diffraction efficiency was achieved. The increase in the diffraction efficiency was related to the growth of the refractive-index contrast of the grating. In particular, under illumination, the viscous material escaped from the irradiated area. This feature explains the experimentally observed changes in the values of the grating’s refractive index

Engineered plasmonic Thue-Morse nanostructures for LSPR detection of the pesticide Thiram

AbstractIn this paper, the size- and shape-dependent spectral characteristics of plasmonic nanostructures based on the Thue-Morse (ThMo) sequence are investigated in theory and experiment. We designed, fabricated, and characterized nine different Au nanopillars (NPs) lattices to evaluate their use as nanosensors based on localized surface plasmon resonances (LSPR). The extinction spectra and the bulk refractive index sensitivity (m) are compared to three selected shapes of the NPs (square, circular, and triangular) with different minimum interparticle distance. The maximum m of 275 nm/RIU is obtained for a ThMo pattern with square NPs. Finally, a detection limit of 260 pM (62 pg/ml) of Thiram pesticide has been achieved using an LSPR nanosensor based on an optimized ThMo pattern with triangular NPs employing a phase-sensitive setup to increase the figure-of-merit (FOM) of the sensor

Appendiceal goblet cell carcinoma has marginal advantages from perioperative chemotherapy: a population-based study with an entropy balancing analysis

PurposeThe aim is to clarify the use of perioperative chemotherapy in resectable goblet cell carcinoma (GCC).MethodsA retrospective study was carried out based on the Surveillance, Epidemiology, and End Results study. The population was divided: into patients who received only radical surgery (group A) and those who received radical surgery plus chemotherapy (group B). An entropy balancing was carried out to correct the imbalance between the two groups. Two models were generated. Model 1 contained only high-risk patients: group B and a "virtual" group A with similar characteristics. Model 2 included only low-risk patients: group A and "virtual" group B with identical attributes. The efficacy of entropy balancing was evaluated with the d value. The overall survival was compared and reported with Hazard Ratio (HR) within a confidence interval of 95% (95 CI).ResultsThe groups A and B were imbalanced for tumor size (d = 0.392), T (d = 1.128), N (d = 1.340), M (d = 1.456), mean number of positive lymph nodes (d = 0.907), and LNR (d = 0.889). Before the balancing, the risk of death was higher in group B than in A (4.3; 2.5 to 7.4). After reweighting, all large differences were eliminated (d < 0.200). In high-risk patients, the risk of death was higher in patients who underwent surgery alone than those who received perioperative chemotherapy (HR 0.5; 0.2 to 1.3) without statistical significance (p = 0.187). In low-risk patients, the risk of death was similar (HR 1.1; 0.3 to 3.3).ConclusionPerioperative chemotherapy could provide some marginal advantages to high-risk patients

Comparing the use of ERA5 reanalysis dataset and ground-based agrometeorological data under different climates and topography in Italy

Study region: The study region is represented by seven irrigation districts distributed under different climate and topography conditions in Italy. Study focus: This study explores the reliability and consistency of the global ERA5 single levels and ERA5-Land reanalysis datasets in predicting the main agrometeorological estimates commonly used for crop water requirements calculation. In particular, the reanalysis data was compared, variable-by-variable (e.g., solar radiation, R-s; air temperature, T-air; relative humidity, RH; wind speed, u(10); reference evapotranspiration, ET0), with in situ agrometeorological obser-vations obtained from 66 automatic weather stations (2008-2020). In addition, the presence of a climate-dependency on their accuracy was assessed at the different irrigation districts. New hydrological insights for the region: A general good agreement was obtained between observed and reanalysis agrometeorological variables at both daily and seasonal scales. The best perfor-mance was obtained for T-air, followed by RH, R-s, and u(10) for both reanalysis datasets, especially under temperate climate conditions. These performances were translated into slightly higher accuracy of ET0 estimates by ERA5-Land product, confirming the potential of using reanalysis datasets as an alternative data source for retrieving the ET0 and overcoming the unavailability of observed agrometeorological data

Reliability of forced internal rotation and active internal rotation to assess lateral instability of the biceps pulley

Purpose: the aim of this study was to investigate the relationship between positive painful forced internal rotation (FIR) and lateral pulley instability in the presence of a pre-diagnosed posterosuperior cuff tear. The same investigation was conducted for painful active internal rotation (AIR). Methods: a multicenter prospective study was conducted in a series of patients scheduled to undergo arthroscopic posterosuperior cuff repair. Pain was assessed using a visual analog scale (VAS) and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) was administered. The VAS score at rest, DASH score, and presence/absence of pain on FIR and AIR were recorded and their relationships with lesions of the lateral pulley, cuff tear patterns and shape of lesions were analyzed. Results: the study population consisted of 115 patients (mean age: 55.1 years) recruited from 12 centers. The dominant arm was affected in 72 cases (62.6%). The average anteroposterior extension of the lesion was 1.61 cm. The mean preoperative VAS and DASH scores were 6.1 and 41.8, respectively. FIR and AIR were positive in 94 (81.7%) and 85 (73.9%) cases, respectively. The lateral pulley was compromised in 50 cases (43.4%). Cuff tears were partial articular in 35 patients (30.4%), complete in 61 (53%), and partial bursal in 19 (16.5%). No statistical correlation between positive FIR or AIR and lateral pulley lesions was detected. Positive FIR and AIR were statistically associated with complete lesions. Negative FIR was associated with the presence of partial articular tears. Conclusions: painful FIR in the presence of a postero-superior cuff tear does not indicate lateral pulley instability. When a cuff tear is suspected, positive FIR and AIR are suggestive of full-thickness tear patterns while a negative FIR suggests a partial articular lesion. Level of evidence: level I, validating cohort study with good reference standards

Top-Performance Transmission Gratings with Haloalkanes-Based Polymeric Composite Materials

We report on highly transparent holographic phase transmission volume gratings recorded in the visible region at λ = 532 nm. The maximum measured diffraction efficiency is higher than 80% with a grating pitch of Λ≈ 300 nm and a refractive index modulation Δn ≈ 0.018. To obtain these results, we used a holographic mixture based on multi-reticulated acrylate and haloalkanes (1-bromo-butane and 1-bromo-hexane) and a synergic combination of camphore-quinone, which has a maximum absorbance at c.a. 470 nm, and R6G, here used as co-initiator, to efficiently initiate the photo-polymerization process. High transparent and high efficient holographic structures based on polymers can find applications in many research fields including integrated optics, sensors, high density data storage and security