Impurity conduction in phosphorus-doped buried-channel silicon-on-insulator field-effect transistors

We investigate transport in phosphorus-doped buried-channel metal-oxide-semiconductor field-effect transistors at temperatures between 10 and 295 K. In a range of doping concentration between around 2.1 and 8.7 x 1017 cm-3, we find that a clear peak emerges in the conductance versus gate-voltage curves at low temperature. In addition, temperature dependence measurements reveal that the conductance obeys a variable-range-hopping law up to an unexpectedly high temperature of over 100 K. The symmetric dual-gate configuration of the silicon-on-insulator we use allows us to fully characterize the vertical-bias dependence of the conductance. Comparison to computer simulation of the phosphorus impurity band depth-profile reveals how the spatial variation of the impurity-band energy determines the hopping conduction in transistor structures. We conclude that the emergence of the conductance peak and the high-temperature variable-range hopping originate from the band bending and its change by the gate bias. Moreover, the peak structure is found to be strongly related to the density of states (DOS) of the phosphorus impurity band, suggesting the possibility of performing a novel spectroscopy for the DOS of phosphorus, the dopant of paramount importance in Si technology, through transport experiments.Comment: 9 figure

チタン鋳造における鋳型温度の影響

The purpose of this study was to evaluate the titanium castability with a vacuum pressured type casting machine. We tested ethyl-silicate bonded investment "TITAVESTPS" of metal frame work. Four different mold temperatures (room temperature, 300℃, 600℃, and 900℃) were prepared for the present study, and casting was done in five times in each condition. When the mold temperature increased, high percentage of castability was gained. Mold temperature showed a highly significant (p<0.001) correlation on the castability. These results indicate that high performance of castability on the titanium was achieved when the mold temperature increased by using vacuum pressured type casting machine

Efficacy and Safety of Intravitreal Aflibercept Treat-and-Extend Regimens in Exudative Age-Related Macular Degeneration: 52- and 96-Week Findings from ALTAIR : A Randomized Controlled Trial.

PURPOSE:To evaluate efficacy and safety of intravitreal injections of aflibercept (IVT-AFL) treat-and-extend (T&E) dosing regimens in treatment-naïve patients with exudative age-related macular degeneration (AMD).METHODS:Adults aged at least 50 years old with exudative AMD and best-corrected visual acuity (BCVA) of 73-25 Early Treatment Diabetic Retinopathy Study (ETDRS) letters were included. Patients received three monthly doses of IVT-AFL 2 mg. At week 16, patients were randomized 1:1 to IVT-AFL T&E with either 2- or 4-week adjustments. The primary endpoint was mean change in BCVA from baseline to week 52. Outcomes were assessed at weeks 52 and 96.RESULTS:Baseline characteristics were comparable between the groups (n = 123 each). Over 52 weeks, mean number of injections was 7.2 and 6.9 and mean last injection interval was 10.7 and 11.8 weeks, for the 2- and 4-week groups, respectively. From baseline, mean change in BCVA was + 9.0 and + 8.4 letters (week 52) and + 7.6 and + 6.1 letters (week 96); mean change in central retinal thickness was - 134.4 µm and - 126.1 µm (week 52) and - 130.5 µm and - 125.3 µm (week 96). Last injection interval before week 52 was at least 12 weeks in 42.3% and 49.6% of patients and 56.9% and 60.2% before week 96. Over 96 weeks, mean number of injections was 10.4 (both groups). The safety profile of IVT-AFL was consistent with previous reports.CONCLUSIONS:IVT-AFL administered using two different T&E regimens for treatment-naïve exudative AMD improved functional and anatomic outcomes at week 52 and outcomes were maintained to week 96. Outcomes were similar between the 2- and 4-week groups.TRIAL REGISTRATION:ClinicalTrials.gov identifier, NCT02305238

Molecular dynamics simulation of the formation of sp3 hybridized bonds in hydrogenated diamondlike carbon deposition processes

Yasuo Murakami, Seishi Horiguchi, and Satoshi Hamaguchi, Physical Review E 81, 041602, 201

A Clinicopathologic Study of Breast Cancer Patients during Pregnancy

Background & Aims: The purpose of this study was to investigate the influence of pregnancy on breast cancer prognosis by analyzing clinical and pathological features of young patients with breast cancer in relation to last birth. Method: A total of 622 young breast cancer patients under 35 years of age undergoing surgical treatment between 1960 and 1990 at Cancer Institute Hospital were included in this study. The patients were classified into four groups; group A patients who were diagnosed during pregnancy or within one year after delivery, group B patients who were diagnosed from one to three years after delivery, group C patients who were diagnosed three years or more after delivery, and group D patients who were nulliparous. All four groups were examined from the viewpoint of clinical and pathological findings with regard to age, disease duration, first childbirth, clinical stage, histopathological type, lymph node metastasis, and survival. Furthermore, nuclear grade and immunohistochemical staining of both estrogen receptor (ER) and factor-VIII were examined in early-stage breast cancer patients. Result: The incidence of early-stage(0, I and II) breast cancer was significantly(p＜ 0.05) lower in group A (69％) than in groups C (88％) and D (85％). The incidence of nodal involvement decreased from group A (61％), B (59％), C (51％) to D (43％) in that order. The incidence of nodal involvement in group D was significantly (p＜0.05) lower than that in groups A and B. The positive rate of estrogen receptor increased from group A (50％), B (56％) to C (72％) in that order. Disease-free survival was significantly (p＜0.05) more favorable in group D than in groups A and C. The similar result was obtained in patients with clinically early-stage breast cancer. Conclusion: Patients who developed breast cancer during pregnancy or within less than one year postpartum have a poor prognosis among patients under 35 years old. Patients having no childbirth history generally have a high risk factor of developing breast cancer, however, breast cancer patients without childbirth history under 35 years old result in a favourable prognosis

Transclival clipping for giant vertebral artery aneurysm: A case report

Background: Endovascular treatment often achieves complete obliteration of VA giant aneurysm; however, retreatmentmay be required because of late recanalization. We report a case of giant VA aneurysm that showedregrowth after endovascular treatment and was treated with VA clipping using the endoscopic endonasaltransclival approach.Case description: A 47-year-old man with chief complaint of ataxia underwent endovascular treatment of giantVA aneurysm. One year later, he needed additional treatment to regrowth of the aneurysm. We were not able toaccomplish aneurysmectomy via the transcondylar fossa approach because of difficulty in achieving hemostasisand ended with partial thrombectomy. Digital subtraction angiography (DSA) performed after 4 months revealedcoil compaction and distal flow due to recanalization. Right VA elongation and position of anterior spinal artery(ASA), these factors made possible for us to perform transclival approach to VA. Despite the limited indicationsfor its use, endonasal endoscopic transclival clipping may be effective in limited anatomical cases.Conclusion: We report the use of endonasal endoscopic transclival clipping for giant VA aneurysm. This endonasalendoscopic treatment may be an optional alternative in only limited cases depending upon the anatomicallocation of the lesion because of limitations of vascular control and the inability to visualize the field in thepresence of major bleeding. For treatment of progressive giant VA aneurysm, it is very important to avoidoptimistic strategy for giant VA aneurysm initially