Charge Storage Effects in Pseudomorphic High Electron Mobility Transistors

We present for the first time results on charging effects in fully fabricated pseudomorphic high electron mobility transistors (PHEMTs), using in-situ, photoemission and conduction (PEC) studies. The experiments were performed on GaAs based FETs with strained InGaAs channels. These studies evaluate hole storage in the channel area which modifies the threshold voltage of the field effect transistors (FETs). Deep level transient spectroscopy (DLTS) measurements were performed and the results compared to the data obtain from the photo studies. Understanding of hole storage is of significance in modeling the devices since holes are attracted towards the channel when the device is pinched off

Charge Storage Effects in Pseudomorphic High Electron Mobility Transistors

We present for the first time results on charging effects in fully fabricated pseudomorphic high electron mobility transistors (PHEMTs), using in-situ, photoemission and conduction (PEC) studies. The experiments were performed on GaAs based FETs with strained InGaAs channels. These studies evaluate hole storage in the channel area which modifies the threshold voltage of the field effect transistors (FETs). Deep level transient spectroscopy (DLTS) measurements were performed and the results compared to the data obtain from the photo studies. Understanding of hole storage is of significance in modeling the devices since holes are attracted towards the channel when the device is pinched off

Phase 1 study of intravenous administration of the chimeric adenovirus enadenotucirev in patients undergoing primary tumor resection.

Background Enadenotucirev (formerly ColoAd1) is a tumor-selective chimeric adenovirus with demonstrated preclinical activity. This phase 1 Mechanism of Action study assessed intravenous (IV) delivery of enadenotucirev in patients with resectable colorectal cancer (CRC), non-small-cell lung cancer (NSCLC), urothelial cell cancer (UCC), and renal cell cancer (RCC) with a comparator intratumoral (IT) dosed CRC patient cohort. Methods Seventeen patients scheduled for primary tumor resection were enrolled. IT injection of enadenotucirev (CRC only) was administered as a single dose (≤ 3 × 1011 viral particles [vp]) on day 1, followed by resection during days 8–15. IV infusion of enadenotucirev was administered by three separate doses (1 × 1012 vp) on days 1, 3, and 5, followed by resection during days 8–15 (CRC) or days 10–25 (NSCLC, UCC, and RCC). Enadenotucirev activity was measured using immunohistochemical staining of nuclear viral hexon and quantitative polymerase chain reaction for viral genomic DNA. Results Delivery of enadenotucirev was observed in most tumor samples following IV infusion, with little or no demonstrable activity in normal tissue. This virus delivery (by both IV and IT dosing) was accompanied by high local CD8+ cell infiltration in 80% of tested tumor samples, suggesting a potential enadenotucirev-driven immune response. Both methods of enadenotucirev delivery were well tolerated, with no treatment-associated serious adverse events. Conclusions This study provides key delivery and feasibility data to support the use of IV infusion of enadenotucirev, or therapeutic transgene-bearing derivatives of it, in clinical trials across a range of epithelial tumors, including the ongoing combination study of enadenotucirev with the checkpoint inhibitor nivolumab. It also provides insights into the potential immune-stimulating properties of enadenotucirev.</p

Malignant colonic adenomas. Therapeutic criteria: Long-term results of therapy in a series of 42 patients in our healthcare area Adenomas malignos de colon. Criterios terapéticos: Resultados a largo plazo después de un tratamiento de una serie de 42 pacientes en nuestra área sanitaria

Objective: a) to evaluate the appropriateness of histological criteria as proposed by Morson as indicators for surgery; and b) to compare the adequacy of Morson's criteria with Haggitt's levels as indicators for surgery in the case of malignant sessile lesions. Material and methods: we carried out a prospective, protocolized study of 42 patients with polyps with invasive carcinoma (IC) who underwent colonoscopic polypectomy from 1979 through 2008. We applied the histological criteria proposed by Morson to all the patients included in the series. Results: we treated 24 polyps with IC and favorable histological criteria (FC) and 18 polyps showing unfavorable histological criteria (UC). All polyps with FC were treated by means of colonoscopic polypectomy. None of the patients showed signs of disease after a mean follow-up period o f 9.67 yrs. Patients with polyps with UC were recommended to undergo surgery. The presence of unfavorable histological criteria in the polypectomy sample was clearly associated with an unfavorable patient outcome and showed a 100% sensitivity level, a negative prognostic value (NPV) of 100%, and a false negative (FN) percentage of 0% for the prognosis of the disease. We found 12 sessile polyps (Haggitt's level 4). Colonoscopic polypectomy was the treatment employed in 9 out of 12 cases. All patients are free from disease (mean follow-up 7.3 yrs). If Haggitt's level criteria had been applied, all 12 patients would have undergone surgery. This means 58% more patients than following Morson's criteria. Conclusions: Morson's criteria are considered an adequate diagnostic tool for the indication of surgery in patients with malignant adenomas. Haggitt's invasion levels do not accurately discriminate the necessity for surgery in case of malignant sessile lesions

Wet Chemical Digital Etching of GaAs at Room Temperature

A new room temperature wet chemical digital etching technique for GaAs is presented which uses hydrogen peroxide and an acid in a two‐step etching process to remove GaAs in approximately 15 Å increments. In the first step, GaAs is oxidized by 30% hydrogen peroxide to form an oxide layer that is diffusion limited to a thickness of 14 to 17 Å for time periods from 15 to 120 s. The second step removes this oxide layer with an acid that does not attack unoxidized GaAs. These steps are repeated in succession until the desired etch depth is obtained. Experimental results are presented for this digital etching technique demonstrating the etch rate and process invariability with respect to hydrogen peroxide and acid exposure times