199 research outputs found
Effects of dihydrotanshinone I on proliferation and invasiveness of paclitaxel-resistant anaplastic thyroid cancer cells
ATC is a very rare, but extremely aggressive form of thyroid malignancy, responsible for the highest mortality rate registered for thyroid cancer. In patients without known genetic aberrations, the current treatment is still represented by palliative surgery and systemic mono-or combined chemotherapy, which is often not fully effective for the appearance of drug resistance. Comprehension of the mechanisms involved in the development of the resistance is therefore an urgent issue to suggest novel therapeutic approaches for this very aggressive malignancy. In this study, we created a model of anaplastic thyroid cancer (ATC) cells resistant to paclitaxel and investigated the characteristics of these cells by analyzing the profile of gene expression and comparing it with that of paclitaxel-sensitive original ATC cell lines. In addition, we evaluated the effects of Dihydrotanshinone I (DHT) on the viability and invasiveness of paclitaxel-resistant cells. ATC paclitaxel-resistant cells highlighted an overexpression of ABCB1 and a hyper-activation of the NF-\u3baB compared to sensitive cells. DHT treatment resulted in a reduction of viability and clonogenic ability of resistant cells. Moreover, DHT induces a decrement of NF-\u3baB activity in SW1736-PTX and 8505C-PTX cells. In conclusion, to the best of our knowledge, the results of the present study are the first to demonstrate the antitumor effects of DHT on ATC cells resistant to Paclitaxel in vitro
a new digital signal processing method for spectrum interference monitoring
Frequency spectrum is a limited shared resource, nowadays interested by an ever growing number of different applications. Generally, the companies providing such services pay to the governments the right of using a limited portion of the spectrum, consequently they would be assured that the licensed radio spectrum resource is not interested by significant external interferences. At the same time, they have to guarantee that their devices make an efficient use of the spectrum and meet the electromagnetic compatibility regulations. Therefore the competent authorities are called to control the access to the spectrum adopting suitable management and monitoring policies, as well as the manufacturers have to periodically verify the correct working of their apparatuses. Several measurement solutions are present on the market. They generally refer to real-time spectrum analyzers and measurement receivers. Both of them are characterized by good metrological accuracies but show costs, dimensions and weights that make no possible a use "on the field". The paper presents a first step in realizing a digital signal processing based measurement instrument able to suitably accomplish for the above mentioned needs. In particular the attention has been given to the DSP based measurement section of the instrument. To these aims an innovative measurement method for spectrum monitoring and management is proposed in this paper. It performs an efficient sequential analysis based on a sample by sample digital processing. Three main issues are in particular pursued: (i) measurement performance comparable to that exhibited by other methods proposed in literature; (ii) fast measurement time, (iii) easy implementation on cost-effective measurement hardware
Raman Microspectroscopy Analysis in the Treatment of Acanthamoeba Keratitis
Acanthamoeba keratitis is a rare but serious corneal disease, often observed in contact lens wearers. Clinical treatment of infected patients frequently involves the use of polyhexamethylene biguanide (PHMB), a polymer used as a disinfectant and antiseptic, which is toxic also for the epithelial cells of the cornea. Prompt and effective diagnostic tools are hence highly desiderable for both starting early therapy and timely suspension of the treatment. In this work we use Raman microspectroscopy to analyse in vitro a single Acanthamoeba cell in cystic phase. In particular, we investigate the effect of PHMB at the single-cell level, providing useful information on both the underlying biochemical mechanism and the time frame for Acanthamoeba eradication in ocular infections. Furthermore, we demonstrate that Raman spectroscopy, in conjunction with standard multivariate analysis methods, allows discriminating between live and dead Acanthamoebas, which is fundamental to optimizing patients' treatment
Is there a role for endocannabinoids in sperm–oviduct interaction?
The endocannabinoid system (ECS) has been found in reproductive cells and tissues in several mammals. Spermatozoa are able to respond to anandamide, and the oviduct is able to synthesize and modulate the concentration of this endocannabinoid along the isthmic and ampullary regions. The main aim of this study was to understand whether the ECS has a role during sperm storage and release within the oviduct in cattle. Data showed that 1) the endocannabinoid receptors 1 and 2 (CB1 and CB2) are present in bovine spermatozoa both in the initial ejaculate and in spermatozoa bound to the oviduct in vitro; 2) CB1 receptor is still detectable in spermatozoa released from the oviduct through penicillamine but not in those released through heparin; 3) arachidonylethanolamide (AEA) does not affect sperm viability, whereas it depresses sperm progressive motility and kinetic values; 4) sperm–oviduct binding and release in vitro are not influenced by AEA; 5) AEA depresses sperm–zona pellucida (ZP) binding; 6) binding of heparin-capacitated spermatozoa to the ZP is not affected by AEA; 7) N-acylphosphatidylethanolamine-selective phospholipase D, the main enzyme involved in anandamide synthesis, is expressed in oviductal epithelial cells. In conclusion, secretion of AEA from epithelial cells might contribute to the oviduct sperm-reservoir function, prolonging the sperm fertile life through the depression of motility and capacitation. Capacitation signals, such as heparin, that promote sperm release, might remodel the sperm surface and cause a loss of the sperm sensitivity to AEA
Use of frequency diversity to improve the performance of RSSI-based distance measurements
In several fields of application of wireless sensors networks (WSNs) the ability of estimating the position of a node with respect to a reference coordinate is a key feature. The most of the WSN applications involve indoor environments and low costs requirements, so the Global Position System cannot always assure a reliable operating and cheap solution. As a consequence, other methods have to be considered for nodes locating, among all, the most widespread methods are based on Received Signal Strength Indicator (RSSI) measurements. The main advantage of this method is that it does not require additional hardware since the measurement of RSSI is often built-in in radio chipsets for the most common standards in use for a WSN (Bluetooth, Wi-Fi, ZigBee). However, solutions based on RSSI measurements suffer of high uncertainty due to several phenomena as high variability of RSSI measurements, external interferences and multipath to cite a few. In this paper the influence of the multipath is investigated and the effects of different processing techniques for multipath mitigating, based on the employment of frequency diversity, are analyzed in simulation environment and in real scenarios
Local monitoring of polymerization trend by an interdigital dielectric sensor
Composite materials are increasingly used for advanced applications subjected to high standards of quality that can be guaranteed by sophisticated control systems of the production process. Quality is usually controlled by monitoring temperature inside the laminate, but some researches have also evaluated the degree of cure during the thermal cycle. The goal of this work is to measure the local cure degree of thick laminates presenting a different trend as function of thickness; to achieve this aim, a suitable interdigital dielectric sensor was developed. Sensor development was carried out through FEM simulation, suited to evaluate the electric field inside the laminate: the depth of measurement of the sensor is due to its trend. The sensor was realized after having designed it and it was experimentally verified comparing the cure degree measured in a laminate polymerized in an oven with those recorded through a cure process simulation. A thick laminate was chosen because the cure degree trend is different as function of thickness and this condition is ideal to check if the sensor is able to perform local measurements
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