1,720,992 research outputs found
Second harmonic generation in reverse proton exchanged - Lithium niobate waveguides
No full textWe investigate efficient second harmonic generation in reverse proton exchanged Lithium Niobate waveguides. In z-cut crystals, the resulting buried and surface guides support TM and TE polarizations, respectively, and are coupled through the d 31 nonlinear element. Numerically estimated conversion efficiencies in planar structures operating at 1.32microm reach 90% in 2cm or a normalized 14% microm/Wcm
Late tonsil metastases from renal cell cancer: a case report
No full textThe occurrence of renal carcinoma metastasis to the head and neck region is extremely rare. Some authors have reported metastasis of renal cell carcinoma to the parotid glands, nose and paranasal sinus, tongue, larynx, thyroid and palatine tonsil. In this report we describe a rare case of renal cell cancer metastasized to the right tonsil in a 76-year-old man with previously diagnosed bone and lung metastases. To the best of our knowledge this is the first documented example of radiotherapy treatment in this type of presentation. Radiotherapy was effective in treating the lesion with satisfactory functional results
Adaptive hierarchical origami-based metastructures
Full text linkShape-morphing capabilities are crucial for enabling multifunctionality in both biological and artificial systems. Various strategies for shape morphing have been proposed for applications in metamaterials and robotics. However, few of these approaches have achieved the ability to seamlessly transform into a multitude of volumetric shapes post-fabrication using a relatively simple actuation and control mechanism. Taking inspiration from thick origami and hierarchies in nature, we present a hierarchical construction method based on polyhedrons to create an extensive library of compact origami metastructures. We show that a single hierarchical origami structure can autonomously adapt to over 103 versatile architectural configurations, achieved with the utilization of fewer than 3 actuation degrees of freedom and employing simple transition kinematics. We uncover the fundamental principles governing theses shape transformation through theoretical models. Furthermore, we also demonstrate the wide-ranging potential applications of these transformable hierarchical structures. These include their uses as untethered and autonomous robotic transformers capable of various gait-shifting and multidirectional locomotion, as well as rapidly self-deployable and self-reconfigurable architecture, exemplifying its scalability up to the meter scale. Lastly, we introduce the concept of multitask reconfigurable and deployable space robots and habitats, showcasing the adaptability and versatility of these metastructures.Enabling complex shape morphing in engineering systems remains a significant challenge. In this work, authors demonstrate that a transformer-like hierarchical origami metastructure can self-reconfigure into over 1000 versatile structures with fewer than 3 actuation degrees of freedom and simple control
Dynamic morphological computation through damping design of soft material robots: application to under-actuated grippers
No full textThis article presents the design of soft material robots with tunable damping properties. This study derives from the investigation of an under-actuated dynamic approach involving multi-chamber pneumatic systems. The co-design of the mechanical parameters (stiffness and damping) of the system along with the time profile of the input allows to obtain different behaviors using a reduced number of feeding line. In this work we analyze via simulations and experiments several approaches to tune the damping of soft robots. The most effective solution employs a layer of granular material immersed in viscous oil within the chamber wall. This method has been employed to realize bending actuators with a continuous deformation pattern. Finally, we show an application involving a two-fingered gripper fed by a single pneumatic line, which is able to perform pinch and power grasp
Is the efficacy of intravescical chemotherapy influenced by cigarette smoking? Data obtained in intermediate risk non muscle invasive bladder carcinoma.
No full textAim of the study
To study recurrence-free rate (RFR) and recurrence-free survival (RFS) according to the smoking status in patients affected by non-muscle invasive carcinoma of the bladder (NMI-BC) treated by intravesical chemotherapy.
Materials and methods
Smoking status was recorded at study entry. Intravesical epirubicin was administered within 6 hours from TUR at the dose of 80 mg diluted in 50 ml of saline solution. Further adjuvant treatment in low-risk and high-risk patients was given according to physicians’ choice. The remaining patients, at intermediate risk for recurrence, were randomized between two different schemes of intravesical chemotherapy: 5 more weekly instillations (total of 6 instillations) versus 5 more weekly instillations followed by monthly instillations for 10 months (total of 16 instillations). In the case of tumour recurrence within the first year early intravesical epirubicin was repeated. The treatment was continued monthly to complete one year in patients entered in maintenance arm. All patients were submitted to cytology and cystoscopy 3-monthly for 2 years and then 6-monthly for 3 more years. Multivariate statistical analysis was conducted to study the recurrence risk and the response to intravesical chemotherapy in terms of recurrence-free rate (RFR) and recurrence-free survival (RFS) in relation to smoking status at diagnosis.
The two different regimens of intravesical chemotherapy were compared in intermediate risk patients.
Results
Out of 577 consecutive patients, 241 (42%), 188 (33%) and 148 (25%) were current, former and never smokers, respectively. The mean number of cigarettes per day was 20 for a median period of 30 years. Recurrent tumors were statistically more frequent in smokers that in never smokers.
The percentage increased from 20% to 42% (p<0.0001), between smokers for less or more than 30 years respectively. No statistically significant difference between current and former smokers emerged in terms of RFR and median time to first recurrence, 71.9% and 65.4% (p=0.23) and 15.9 and 11.7 months (p=0.17) respectively. The 3-year RFS in current and former smokers was 68.9% and 57.0% (p=0.06), respectively. These data did not change in former smokers with increasing time since quitting up to 30 years.
The RFS significantly differed between former and never smokers (p=0.019; HR 1.79, C.I. 1.098-2.950). The 3-year RFS was 57.0% and 71.3% respectively.
No difference in RFS was evident between the two schedules of intravesical chemotherapy in never smokers (p=0.78) and former smokers (p=0.47). Moreover, this data remained unchanged increasing the time since quitting up to 30 years. Only in current smokers, although no difference emerged in terms of RFS (p=0.27), an advantage of maintenance was evident in terms of RFR (p=0.04) during the treatment period (12 months), disappearing thereafter.
Conclusions
Recurrent tumors were more frequent in patients smoking for a long period, independently from the number of cigarettes and from smoking cessation.
Former smokers remain at high risk for recurrence up to 30 years since quitting. In patients affected by intermediate risk tumors maintenance regimen after 6-weeks induction intravesical chemotherapy is of benefit only in patients continuing to smoke after diagnosis
Smoking status at diagnosis and outcome of intermediate-risk non muscle-invasive bladder carcinoma (NMI-BC) treated by TUR and adjuvant intravesical chemotherapy
No full textSMOKING STATUS, RECURRENCE RISK AND INTRAVESICAL CHEMOTHERAPY IN NONMUSCLE-INVASIVE BLADDER CANCER
No full textCigarette smoking status at diagnosis and recurrence in intermediate-risk non-muscle-invasive bladder carcinoma.
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