Novel Power Reduction Technique for ReRAM with Automatic Avoidance Circuit for Wasteful Overwrite

Low-power operations can be great advantageous for ReRAM devices. However, wasteful overwriting such as the SET operation to low-resistance state (LRS) device and the RESET operation to high-resistance state (HRS) device causes not only an increase in power but also the degradation of the write cycles due to repeatedly rewriting. Thus, in this paper, we proposed a novel automatic avoidance circuit for dealing with wasteful overwriting that uses a sense amplifier and estimated the energy consumption reduction rate by conducting a circuit simulation. As a result, this circuit helped to reliably avoid the wasteful overwriting operation to reduce about 99% and 97% of wasteful energy using VSRC and CSRC, respectively

Cost-effectiveness analysis of treatment for Koos 2 and 3 vestibular schwannomas: Wait & scan or radiosurgery

Objective: Vestibular schwannomas are benign slowly growing tumors, with 3 treatment options: wait and scan, radiosurgery, and microsurgery with specific advantages and disadvantages. Contemporary debate has focused on medium size tumor. The present study used a Markov model to try to identify the cost-effectiveness in a lifelong perspective of the “wait & scan” or “radiosurgery” strategies for Koos 2 and 3 tumors. Methods: The present model was defined by 5 discrete health states. All decision and chance nodes were assigned a probability of occurrence derived from a thorough review of the related literature. We calculated the expected effects and costs associated with the two strategies, then evaluated the incremental cost-effectiveness ratio. Sensitivity analysis was performed by altering the input values within a clinically reasonable range to assess the effects of uncertainties. Results: Radiosurgery always requires more costs than wait & scan, and seems to generate small effects. However, the incremental cost-effectiveness ratio was significantly influenced by the hazard ratio of risk generated by deferred radiosurgery. One-way and two-way sensitivity analysis indicated that radiosurgery always yields negative effectiveness, compared with wait & scan at hazard ratio of less than 3.0, regardless of any other assumptions. Conclusions: Treatment strategy for medium size vestibular schwannoma should primarily be based on the future increased risk of radiosurgery after failure of conservative management. Wait & scan strategy may be the optimum approach for most Koos 2 and 3 tumors, but relatively large Koos 3 tumors are candidates for immediate radiosurgery

Transplanted human iPSC-derived vascular endothelial cells promote functional recovery by recruitment of regulatory T cells to ischemic white matter in the brain

Abstract Background Ischemic stroke in white matter of the brain induces not only demyelination, but also neuroinflammation. Peripheral T lymphocytes, especially regulatory T cells (Tregs), are known to infiltrate into ischemic brain and play a crucial role in modulation of inflammatory response there. We previously reported that transplantation of vascular endothelial cells generated from human induced pluripotent stem cells (iVECs) ameliorated white matter infarct. The aim of this study is to investigate contribution of the immune system, especially Tregs, to the mechanism whereby iVEC transplantation ameliorates white matter infarct. Methods iVECs and human Tregs were transplanted into the site of white matter lesion seven days after induction of ischemia. The egress of T lymphocytes from lymph nodes was sequestered by treating the animals with fingolimod (FTY720). The infarct size was evaluated by magnetic resonance imaging. Immunohistochemistry was performed to detect the activated microglia and macrophages, T cells, Tregs, and oligodendrocyte lineage cells. Remyelination was examined by Luxol fast blue staining. Results iVEC transplantation reduced ED-1+ inflammatory cells and CD4+ T cells, while increased Tregs in the white matter infarct. Treatment of the animals with FTY720 suppressed neuroinflammation and reduced the number of both CD4+ T cells and Tregs in the lesion, suggesting the importance of infiltration of these peripheral immune cells into the lesion in aggravation of neuroinflammation. Suppression of neuroinflammation by FTY720 per se, however, did not promote remyelination in the infarct. FTY720 treatment negated the increase in the number of Tregs by iVEC transplantation in the infarct, and attenuated remyelination promoted by transplanted iVECs, while it did not affect the number of oligodendrocyte lineage cells increased by iVEC transplantation. Transplantation of Tregs together with iVECs into FTY720-treated ischemic white matter did not affect the number of oligodendrocyte lineage cells, while it remarkably promoted myelin regeneration. Conclusions iVEC transplantation suppresses neuroinflammation, but suppression of neuroinflammation per se does not promote remyelination. Recruitment of Tregs by transplanted iVECs contributes significantly to promotion of remyelination in the injured white matter

Elderly patients aged over 75 years with glioblastoma: Preoperative status and surgical strategies

Background: Standards of care for the elderly with glioblastoma are still unknown, because most studies exclude elderly patients. The effects of preoperative status and surgical strategies on the prognosis for elderly glioblastoma patients were studied. Methods: We defined “elderly” as 75 years or older and retrospectively reviewed 137 patients with glioblastoma, including 31 (22.6%) elderly patients. Relationships between age and clinicopathological variables were investigated. Results: The median overall survival (OS) was 15.8 months in the nonelderly group and 10.8 months in the elderly group (p = 0.02). The median progression-free survival (PFS) was 9.1 months in the nonelderly group and 6.6 months in the elderly group (p = 0.02). Median OS and median PFS had no relationship between low (<70) and high (≥70) Karnofsky performance status (KPS) in the nonelderly group. However, the median OS was significantly longer in the elderly group with high KPS (8.4 months in low KPS, 12.4 months in high KPS; p = 0.003). The median PFS was also significantly longer in the elderly group with high KPS (4.3 months in low KPS, 9.1 months in high KPS; p = 0.04). OS and PFS were significantly longer in the nonelderly group with resection than with biopsy (OS, p = 0.016; PFS, p = 0.039). However, neither OS nor PFS showed any difference with surgical method in the elderly group (OS, p = 0.241; PFS, p = 0.131). Conclusions: Less invasive treatment can be considered as a treatment option in addition to radical resection in glioblastoma patients aged 75 years and older with KPS on admission of less than 70, depending on the general condition

Does Hypoxic Preconditioning Induce Angiogenesis and Protect against Focal Cerebral Ischemic Damage in Rats?

Background and Aims: This study investigated whether hypoxic preconditioning(HP) induces ischemic tolerance in an established experimental model of permanent middle cerebral artery occlusion using rats. Methods: Animals were divided into the normoxia(control) and HP groups. HP was performed under normobaric conditions (7% O2 for 2 hours), 14 days before focal cerebral ischemia induction. the infarct volume was evaluated by quantitative histopathology. Immunofluorescence analysis was assessed at 24 hours after HP to examine the effect on proliferating cell and microglia /macrophage activation. Brain microvessel density was assessed 14 days after HP. Furthermore, the expression was evaluated of angiogenesis-related proteins such as hypoxia-inducible factor-1α and vascular endothelial growth factor proteins. Results: Hemisphere infarct volume in the HP group was significantly smaller than in the control group. Vascular endothelial growth factor and proliferating cell nuclear antigen expression was not increased after HP. HP tended to increase vessel density relative to the control group, but this did not achieve statistical significance. Conclusion: HP attenuated the infarct volume in rats. The phenomenon of ischemic tolerance may link HP with vascular remodeling