Self-selective ferroelectric memory realized with semimetalic graphene channel

A new concept of read-out method for ferroelectric random-access memory (FeRAM) using a graphene layer as the channel material of bottom-gated field effect transistor structure is demonstrated experimentally. The transconductance of the graphene channel is found to change its sign depending on the direction of spontaneous polarization (SP) in the underlying ferroelectric layer. This indicates that the memory state of FeRAM, specified by the SP direction of the ferroelectric layer, can be sensed unambiguously with transconductance measurements. With the proposed read-out method, it is possible to construct an array of ferroelectric memory cells in the form of a cross-point structure where the transconductance of a crossing cell can be measured selectively without any additional selector. This type of FeRAM can be a plausible solution for fabricating high speed, ultra-low power, long lifetime, and high density 3D stackable non-volatile memory

Safety and efficacy study of laparoscopic or robotic radical surgery using an endoscopic stapler for inhibiting tumour spillage of cervical malignant neoplasms evaluating survival (SOLUTION): a multi-centre, open-label, single-arm, phase II trial protocol

The Laparoscopic Approach to Cervical Cancer trial and Surveillance, Epidemiology, and End Results program database study demonstrated that minimally invasive radical hysterectomy was inferior to abdominal radical hysterectomy in terms of disease recurrence and survival. Among risk factors related to poor prognosis after minimally invasive surgery (MIS), tumour spillage during intracorporeal colpotomy became a significant issue. Thus, we designed this trial to evaluate the efficacy and safety of minimally invasive radical hysterectomy using an endoscopic stapler for early-stage cervical cancer. This trial is a prospective, multi-centre, open-label, single-arm, non-inferiority phase II study. The nine organisations will participate in this trial after the approval of the institutional review board. Major eligibility criteria include women aged 20 years or older with cervical cancer stage IB1 squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma according to the revised 2009 FIGO staging system who will undergo type B2 or C hysterectomy by MIS. The primary endpoint is the 4.5-year disease-free survival (DFS) rate between abdominal radical hysterectomy and MIS using an endoscopic stapler. For calculating the sample size, we hypothesised that the 4.5-year DFS rate after MIS using an endoscopic stapler is assumed to be the same after abdominal radical hysterectomy at 90.9%, and the non-inferiority margin was 7.2%. When we consider a three-year accrual and 4.5-year follow-up, at least 13 events must happen, requiring a total of 111 patients assuming a statistical power of 80% and the one-tailed test of 5% significance. A total of 124 patients is needed, considering a drop-out rate of 10%. We expect intracorporeal colpotomy using an endoscopic stapler may prevent tumour spillage during MIS for stage IB1 cervical cancer, showing a comparable prognosis with abdominal radical surgery.This study was supported by Johnson & Johnson. The funder has no role in study design, writing of the manuscript and the decision to submit the report for publication

GAN-Dummy Fill: Timing-aware Dummy Fill Method using GAN

The chemical mechanical polishing (CMP) dummy fill method is commonly used for the planarization of the CMP process, resulting in the development of many automated methods. We propose a dummy fill method using a generative adversarial network (GAN) that improves the existing dummy fill methods in terms of the uniformity of metal density and timing of critical nets. The dummy patterns created were similar to those of existing methods. However, the GAN dummy fill method applies additional optimizations to make the CMP dummy fill pattern efficient. The method learns by adding density and parasitic capacitance to the loss function of the GAN. Compared to dummy patterns generated from commercial tools, dummy patterns generated from GAN-dummy fill reduced the negative timing slack due to parasitic capacitance by up to 45%.1

Accepted for the Council:

examined the final electronic copy of this dissertation for form and content an

Self-Selective Non-Destructive Read-Out for Ferroelectric Memory Based on Field Effect Transistor with Graphene Channel

Ferroelectric graphene field effect transistor (FeGFET) has been studied by several research groups as one way for overcoming the destructive read-out process of ferroelectric random-access memory (FeRAM). In the FeGFET structure, the conductance of graphene channel can vary depending on the direction of spontaneous polarization (SP) in the ferroelectric gate insulator thanks to the linear energy-momentum dispersion relation near the Dirac point [1] and the memory state then can be sensed by measuring the channel conductance. Although the FeGFET structure resolves the problem associated with the destructive read-out process, the low on/off ratio due to the minimal conductance of graphene channel itself brings about the necessity of attaching an additional cell selector (transistor or diode) to each memory cell for realizing the random accessibility [2]. In this work, we experimentally demonstrate a new concept of non-destructive read-out process using transconductance measurement for FeGFET. It is found that the memory state of FeGFET, specified by the SP direction of ferroelectric layer, can be sensed unambiguously by measuring the transconductance of graphene channel. With the proposed read-out method, it is possible to construct an array of ferroelectric memory cells in the form of a cross-point structure where the transconductance of a crossing cell can be measured selectively without any additional selector, which is a main limiting factor in terms of circuit scaling [3]. This read-out process with the FeGFET structure can be a plausible solution for fabricating high speed, ultra-low power, long lifetime, and high-density 3D stackable non-volatile memory. [1] A. K. Geim, and K. S. Novoselov, Nature Materials, 6, 183-191 (2007). [2] X. Zhang, et al, IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT), 1-3 (2014). [3] H. S. P. Wong, et al, Proceedings of the IEEE, 98, 2201-2227 (2010)

Differences in Willingness to Undergo BRCA1/2 Testing and Risk Reducing Surgery among the General Public, Cancer Patients, and Healthcare Professionals: A Large Population-Based Survey

We aimed to understand the decision-making process related to the willingness to undergo BRCA1/2 genetic testing, risk-reducing salpingo-oophorectomy (RRSO), or risk-reducing mastectomy (RRM) among the general public, cancer patients, and healthcare professionals in South Korea. In total, 3444 individuals (1496 from the general public, 1500 cancer patients, 108 clinicians, and 340 researchers) completed a survey addressing genetic testing and related risk management options in a hypothetical scenario. Differences in intent and associated factors for undergoing the above procedures or sharing test results were analyzed. Overall, 67% of participants were willing to undergo BRCA1/2 testing, with proportions of the general public (58%), cancer patients (70%), clinicians (88%), and researchers (90%). The willingness to undergo RRSO was highest among clinicians (58%), followed by among patients (38%), the general public (33%), and researchers (32%) (p < 0.001). Gender, age, education level, and household income were associated with willingness to undergo genetic testing, RRM, and RRSO (p < 0.05). The intent for undergo genetic testing, RRM, and RRSO were affected by many factors. Finally, 69% of the general public intended to share information with family, while this percentage was 92%, 91%, and 94% for patients, clinicians, and researchers, respectively (p < 0.05). These results highlight the requirement for developing targeted educational materials and counseling strategies for facilitating informed decision making