Voltage-tunable dual-band Ge/Si photodetector operating in VIS and NIR spectral range.

Extending and controlling the spectral range of light detectors is very appealing for several sensing and imaging applications. Here we report on a normal incidence dual band photodetector operating in the visible and near infrared with a bias tunable spectral response. The device architecture is a germanium on silicon epitaxial structure made of two back-to-back connected photodiodes. The photodetectors show a broad photoresponse extending from 390nm to 1600nm with the capability to electronically select the shorter (400-1100 nm) or the longer (1000-1600 nm) portion with a relatively low applied voltage. Devices exhibit peak VIS and NIR responsivities of 0.33 and 0.63 A/W, respectively, a low optical crosstalk (<-30dB), a wide dynamic range (>120dB) and, thanks to their low voltage operation, maximum specific detectivities of 7·1011cmHz1/2/W and 2·1010cmHz1/2/W in the VIS and NIR, respectively.

High responsivity SiGe heterojunction phototransistor on silicon photonics platform.

We report on a novel near infrared SiGe phototransistor fabricated by a standard silicon photonics foundry. The device is first investigated by simulations. The fabricated devices are characterized in terms of current-voltage characteristics at different optical power. Typical phototransistors exhibit 1.55µm record responsivity at low optical power exceeding 232A/W and 42A/W at 5V and 1V bias, respectively. A differential detection scheme is also proposed for the dark current cancellation to significantly increase the device sensitivity.

Peritoneal carcinomatosis from unusual cancer origins: Is there a role for hyperthermic intraperitoneal chemotherapy?

INTRODUCTION: Complete cytoreductive surgery (CCRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is the gold standard for curative treatment of peritoneal carcinomatosis (PC) arising from colorectal cancer, peritoneal mesothelioma and peritoneal pseudomyxoma peritonei (PMP). The results of HIPEC remain controversial in PC that originates from ovarian cancer, stomach cancer, neuroendocrine tumors, or sarcoma. HIPEC has also been used, although very rarely, for other malignant carcinomatoses. Its use has been exceptional due either to the rarity of the tumor or because such disease is usually widespread and rarely confined to the peritoneum. The aim of this study was to evaluate the results of CCRS plus HIPEC in patients with PC of unusual origin. METHODS: We performed a retrospective analysis of all patients who underwent CCRS plus HIPEC for PC whose origin was neither gastric, ovarian or colorectal carcinoma, nor neuroendocrine tumor, mesothelioma, PMP or sarcoma. RESULTS: Between 1995 and 2013, 31 patients with 15 PC arising from unusual primary tumors underwent CCRS plus HIPEC. After a median follow-up of 90 months, 10 patients were alive and without recurrence. The overall survival rate at 5 years was 33% with a median survival of 37 months. In univariate analysis, factors of poor prognosis and predictors of recurrence were the performance of immediate postoperative intraperitoneal chemotherapy instead of HIPEC and a peritoneal index ≥ 12. No prognostic impact due to tumor origin could be demonstrated. CONCLUSION: The decision to perform CCRS plus HIPEC for PC arising from unusual cancer origins remains difficult. These patients should be prospectively entered into registries of rare tumors that involve the peritoneum in order to better define indications.

[Colorectal carcinoma in the young. Prognostic factors]. / Il carcinoma colo-rettale nel giovane. Fattori prognostici.

Colorectal carcinoma is the third most frequently diagnosed malignant neoplasm. Usually patients affected by this neoplasia belong to VI decade of life. However approximately 2-8% of tumors arise in patients with age under 40 years. Aim of the study was to analyse the results of surgical treatment of colorectal cancer in patients aged under forty. From January 1987 to December 2002, 46 patients under forty years with colorectal cancer underwent surgical procedure. No perioperative mortality was registered, and complications were evidenced in nine patients (20%). Actuarial five years survival was 33%, and overall mean survival was 53 months. Univariate and multivariate analyses identified as prognostic factors the tumor grade, Dukes' stage, nodal status, and length of symptoms.

Surface EMG modifications after eccentric exercise.

The possibility that the surface electromyographic signal (sEMG) from exercised muscle would show significant changes to demonstrate muscle damage after eccentric contraction (EC) was tested in this study. The experiment lasted five consecutive days. On the first day, six sedentary adult subjects performed two rounds of 35 ECs with the biceps brachii of the non-dominant arm, the other arm being used as control. Individual muscle soreness was assessed on a subjective scale. The analysis of sEMG was performed on the signal recorded during isometric contractions at 80% and 50% of maximal voluntary contraction (MVC), choosing root mean square (RMS) and median frequency (MDF) as synthetic sEMG parameters. MVC was also recorded, and plasma levels of creatine kinase were determined in four subjects. The most important findings which resulted from this study were: (a) spectral parameters are less sensitive to error introduced by electrode repositioning than time domain parameters, and are more sensitive to EC-induced sEMG changes than RMS; (b) a significant shift of MDF power spectra towards low frequencies at 80% and 50% MVC (20% and 5% of decay, respectively) was evident as early as 1 h after EC on the exercised arm; and (c) MDF follows the evolution of muscle damage. We concluded from these results that MDF is suitable for the early and non-invasive detection of sEMG changes induced by EC. In addition, we found further evidence that the observed modifications result from a selective or prevalent damage of type 2B muscle fibres.

Hanging of the hepatic veins septa: a safe control prior and during outflow anastomosis in liver transplantation.

Inferior vena cava (IVC) preservation during orthotopic liver transplantation (OLT) is known as the "piggyback" technique. The end-to-side anastomosis is constructed between the graft's IVC and recipient's hepatic veins using a Satinsky side clamp applied in a transverse position. To stabilize the large Satinsky clamp and preserve a sufficient vascular stump after hepatectomy and before graft implantation, we propose a technical innovation consisting of hanging the septa between the left and middle hepatic vein and between the middle and right hepatic vein using 2 tapes. This technique showed some advantages when performing the caval outflow anastomosis, representing a further technical refinement of the piggyback end-to-side technique for the implantation on the 3 hepatic veins. From November 2001 to September 2012, we performed 272 consecutive OLT at our institution with the piggyback technique using the hanging of the hepatic veins septa in all cases. In conclusion, the hanging of the 3 hepatic veins septa presented in this study represents a simple, safe and reproducible technique for the outflow anastomosis using the piggyback technique.