888 research outputs found
Transient Analysis of Warm Electron Injection Programming of Double Gate SONOS Memories by means of Full Band Monte Carlo Simulation
In this paper we investigate "Warm Electron Injection" as a mechanism for NOR
programming of double-gate SONOS memories through 2D full band Monte Carlo
simulations. Warm electron injection is characterized by an applied VDS smaller
than 3.15 V, so that electrons cannot easily accumulate a kinetic energy larger
than the height of the Si/SiO2 barrier. We perform a time-dependent simulation
of the program operation where the local gate current density is computed with
a continuum-based method and is adiabatically separated from the 2D full Monte
Carlo simulation used for obtaining the electron distribution in the phase
space. In this way we are able to compute the time evolution of the charge
stored in the nitride and of the threshold voltages corresponding to forward
and reverse bias. We show that warm electron injection is a viable option for
NOR programming in order to reduce power supply, preserve reliability and CMOS
logic level compatibility. In addition, it provides a well localized charge,
offering interesting perspectives for multi-level and dual bit operation, even
in devices with negligible short channel effects
Assessment of liver stiffness measurement and ultrasound findings change during inotuzumab ozogamicin cycles for relapsed or refractory acute lymphoblastic leukemia
In adult patients, acute lymphoblastic leukemia (ALL) is a rare hematological cancer with a cure rate below 50% and frequent relapses. With traditional therapies, patients with relapsed or refractory (R/R) ALL have a survival that may be measured in months; in these patients, inotuzumab ozogamicin (IO) is an effective therapy. IO was linked to increased risk of veno-occlusive disease/sinusoid obstruction syndrome (VOD/SOS), liver injury, and various grade of liver-related complications during clinical trials and real-life settings; however, hepatologic monitoring protocol is not established in this population. In our institution, 21 patients who received IO (median of 6 doses of IO administered) for R/R ALL were prospectively followed for hepatologic surveillance, including clinical evaluation, ultrasonography, and liver stiffness measurement (LSM) biochemistry. After a median follow-up of 17.2 months, two SOS events were reported (both after allogeneic transplant) as IO potentially related clinically relevant adverse event. Mild alterations were reported in almost the totality of patients and moderate-severe liver biochemical alterations in a quarter of patients. Within biochemicals value, AST and ALP showed an augment related to IO administration. LSM linearly augmented for each IO course administered. Baseline LSM was related to liver-related changes, especially with the severity of portal hypertension (PH)-related complications. Pre-transplant LSM was higher in patients receiving IO when compared with a control cohort. PH-related complications were discovered in nearly 77% of patients, with clinically significant PH occurrence and development of ascites in 38% and 14%, respectively. This prospective experience constitutes the rationale to design a hepatologic monitoring program in patients receiving IO. LSM may be of pivotal importance in this program, constituting a rapid and effective screening that quantitatively correlates with liver alterations
Two-stage hepatectomy with radioembolization for bilateral colorectal liver metastases: A case report
BACKGROUND Two-stage hepatectomy (TSH) is a well-established surgical technique, used to treat bilateral colorectal liver metastases (CRLM) with a small future liver remnant (FLR). However, in classical TSH, drop-out is reported to be around 25%- 40%, due to insufficient FLR increase or progression of disease. Trans-arterial radioembolization (TARE) has been described to control locally tumor growth of liver malignancies such as hepatocellular carcinoma, but it has been also reported to induce a certain degree of contralateral liver hypertrophy, even if at a lower rate compared to portal vein embolization or ligation. CASE SUMMARY Herein we report the case of a 75-year-old female patient, where TSH and TARE were combined to treat bilateral CRLM. According to computed tomography (CT)-scan, the patient had a hepatic lesion in segment VI-VII and two other confluent lesions in segment II-III. Therefore, one-stage posterior right sectionectomy plus left lateral sectionectomy (LLS) was planned. The liver volumetry estimated a FLR of 38% (segments I-IV-V-VIII). However, due to a more than initially planned, extended right resection, simultaneous LLS was not performed and the patient underwent selective TARE to segments II-III after the first surgery. The CT-scan performed after TARE showed a reduction of the treated lesion and a FLR increase of 55%. Carcinoembryonic antigen and CA 19.9 decreased significantly. Nearly three months later after the first surgery, LLS was performed and the patient was discharged without any postoperative complications. CONCLUSION According to this specific experience, TARE was used to induce liver hypertrophy and simultaneously control cancer progression in TSH settings for bilateral CRLM
Hierarchy of Full Band Structure Models for Monte Carlo Simulation
This paper discusses the various hierarchy levels that are possible when the full band structure
is considered. At the highest level, the scatterings are treated using complete k-k' transition
rates, which entail extremely memory intensive computational applications. At the
lowest level, the scattering anisotropy is neglected and the scattering rate is considered to be a
constant average value on energy isosurfaces of the bandstructure. This model is more practical
for device simulation. In between the two extremes, it is possible to design intermediate
models which preserve some essential features of both. At all levels of the band structure
hierarchy of models, there are similar issues of numerical noise, related to the sampling of
real and momentum space that the Monte Carlo method necessarily performs with a relatively
small number of particles. We discuss here computationally efficient approaches based on the
assignment of variable weights to the simulated particles, in conjunction with careful gatherscatter
procedures to split particles of large weight and combine particles of small weight
Controlling quantum transport through a single molecule
We investigate multi-terminal quantum transport through single monocyclic
aromatic annulene molecules, and their derivatives, using the nonequilibrium
Green function approach in the self-consistent Hartree-Fock approximation. A
new device concept, the Quantum Interference Effect Transistor (QuIET) is
proposed, exploiting perfect destructive interference stemming from molecular
symmetry, and controlling current flow by introducing decoherence and/or
elastic scattering that break the symmetry. This approach overcomes the
fundamental problems of power dissipation and environmental sensitivity that
beset many nanoscale device proposals.Comment: 4 pages, 5 figure
Unlocking the Power of Late-Evening Snacks: Practical Ready-to-Prescribe Chart Menu for Patients with Cirrhosis
The efficacy of the late-evening snack (LES) has been extensively studied due to the impact of the longest intermeal duration occurring at night in patients with cirrhosis. While actual clinical guidelines on nutrition in chronic liver disease recommend an LES, no specific nutritional compositions have been reported by the European Association for the Study of the Liver (EASL) and the European Society for Clinical Nutrition and Metabolism (ESPEN). Late-evening snacks vary greatly among studies, including natural foods and/or nutritional supplements, yet oral supplements still need to fully meet the LES's nutritional composition. In addition, many hepatologists need to gain experience in nutritional approaches and have access to registered dieticians who can help them manage patients with liver disease. Therefore, this review study aims to summarise evidence regarding using LESs and the mechanisms behind long starvation in patients with cirrhosis. It also provides a practical nutritional guide with several LES options based on common natural foods tailored to special patients' nutritional requirements and geographical backgrounds. In preventing accelerated starvation and related protein malnutrition and sarcopenia in patients with cirrhosis, the nutritional composition of LESs is essential. The proper and straightforward application of the LES's rational nutrition is an advantage to cirrhotic patients and should be carried out by healthcare professionals to enhance the overall liver function and nutritional status of patients with cirrhosis
Liver transplantation for hepatocellular carcinoma: further considerations on selection criteria
The selection criteria in liver transplantation for HCC are a matter of debate. We reviewed our series, comparing two periods: before and after 1996, when we started to apply the Milan criteria. The study population was composed of patients with a preoperative diagnosis of HCC, confirmed by the pathological report and with a survival of > 1 year. Preoperative staging as revealed by radiological imagining was distinguished from postoperative data, including the variable of tumor volume. After 1996 tumor recurrences significantly decreased (6 out of 15 cases, 40% vs. 3 out of 48, 6.3%, P < .005) and 5-year patient survival improved (42% vs. 83%, P < .005). Not meeting the Milan criteria was significantly related to higher recurrence rate (37.5% vs. 12.7%, P < .05) and to lower 5-year patient survival (38% vs. 78%, P < .005%) in the preoperative analysis, but not in the postoperative one. The alfa-fetoprotein level of more than 30 ng/dL and the preoperative tumor volume of more than 28 cm3 predicted HCC recurrences in the univariate and mutivariate analysis (P < .005 and P < .05, respectively). The ROC curve showed a linear correlation between preoperative tumor volume and HCC recurrence. Milan criteria significantly reduced tumor recurrences after liver transplantation, improving long-term survival. In conclusion, the efficacy of tumor selection criteria must be analyzed with the use of preoperative data, to avoid bias of the postoperative evaluation. Tumor volume and alfa-fetoprotein level may improve the selection of patients. Copyright © 2004 by the American Association for the Study of Liver Diseases
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