482 research outputs found

    Diffusion behavior of delta-doped Si in InAlAs/InP heterostructures

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    Diffusion behavior of delta-doped Si in InAlAs and InP was studied by using secondary ion mass spectroscopy. A significant broadening of the profile due to postgrowth annealing was observed in In0.52Al0.48As. In contrast, the depth profile of delta-doped Si in InP was scarcely changed by annealing. This indicates that the diffusion coefficient of delta-doped Si in InP is much smaller than that in In0.52Al0.48As. Suppression of Si diffusion by using a delta-doped InP layer as the carrier supply layer (CSL) improves the thermal stability of the InP-HEMT structures

    A synthetic small molecule for rapid induction of multiple pluripotency genes in mouse embryonic fibroblasts.

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    Cellular reprogramming involves profound alterations in genome-wide gene expression that is precisely controlled by a hypothetical epigenetic code. Small molecules have been shown to artificially induce epigenetic modifications in a sequence independent manner. Recently, we showed that specific DNA binding hairpin pyrrole-imidazole polyamides (PIPs) could be conjugated with chromatin modifying histone deacetylase inhibitors like SAHA to epigenetically activate certain pluripotent genes in mouse fibroblasts. In our steadfast progress to improve the efficiency of SAHA-PIPs, we identified a novel compound termed, δ that could dramatically induce the endogenous expression of Oct-3/4 and Nanog. Genome-wide gene analysis suggests that in just 24 h and at nM concentration, δ induced multiple pluripotency-associated genes including Rex1 and Cdh1 by more than ten-fold. δ treated MEFs also rapidly overcame the rate-limiting step of epithelial transition in cellular reprogramming by switching "[Formula: see text]" the complex transcriptional gene network

    Enhancement of pacing function by HCN4 overexpression in human pluripotent stem cell-derived cardiomyocytes

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    Background The number of patients with bradyarrhythmia and the number of patients with cardiac pacemakers are increasing with the aging population and the increase in the number of patients with heart diseases. Some patients in whom a cardiac pacemaker has been implanted experience problems such as pacemaker infection and inconvenience due to electromagnetic interference. We have reported that overexpression of HCN channels producing a pacemaker current in mouse embryonic stem cell-derived cardiomyocytes showed enhanced pacing function in vitro and in vivo. The aim of this study was to determine whether HCN4 overexpression in human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) can strengthen the pacing function of the cells. Methods Human HCN4 was transduced in the AAVS1 locus of human induced pluripotent stem cells by nucleofection and HCN4-overexpressing iPSC-CMs were generated. Gene expression profiles, frequencies of spontaneous contraction and pacing abilities of HCN4-overexpressing and non-overexpressing iPSC-CMs in vitro were compared. Results HCN4-overexpressing iPSC-CMs showed higher spontaneous contraction rates than those of non-overexpressing iPSC-CMs. They responded to an HCN channel blocker and beta adrenergic stimulation. The pacing rates against parent iPSC line-derived cardiomyocytes were also higher in HCN4-overexpressing iPSC-CMs than in non-overexpressing iPSC-CMs. Conclusions Overexpression of HCN4 showed enhancement of I-f current, spontaneous firing and pacing function in iPSC-CMs. These data suggest this transgenic cell line may be useful as a cardiac pacemaker

    <原著>副腎腫瘤の臨床的検討

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    We reviewed the records of 13 patients with adrenal masses operated on over a ten-year period to clarify clinical characteristics of adrenal tumors. Tumors were found incidentally in seven of nine patients with primary adrenal tumors (78%); however, three of these seven patients (43%) proved to have shown symptoms related to adrenal hyperfunction when re-e、raluated. Other adrenal tumors (metastatic in three patients and inflammatory in one) were found without any symptoms referable to the tumors. In nine of 13 patients (69%), tumors were discovered by computerized tomography (CT). All patients with primary tumors have been gotten free of disease postoperatively. In contrast, although all three patients with metastatic adrenal tumors underwent resection of all known disease tissue, they died of the recurrence of malignancies within 10 months. This study suggests that a number of functional adrenal tumors are possibly left undiagnosed until found incidentally, and that CT is the most powerful tool to detect adrenal tumors. Our data did not support surgical intervention in cases of metastatic adrenal tumors.副腎腫瘤の臨床的特徴を明らかにするために過去10年間に当科で手術された13例を検討した. 原発性腫瘍9例中2例は臨床症状より原発性アルドステロン症を疑われ副腎腫瘍を発見されているが, 残りの7例(78%)は偶然腫瘍が発見された, いわゆる incidentaloma であった. しかしながら, retrospective にみるとこの7例中3例(43%)で副腎機能亢進によると考えられる症状を呈していた. 転移性腫瘍3例, histoplasma による肉芽腫1例は全て無症状であった. 13例中9例(69%)はCTにより, 2例は超音波, 1例は血管造影, 1例は scintigraphy によりそれぞれ病変を発見され, CT で副腎腫瘤を指摘できなかったのは1例のみであった. 13例中11例は経腹的に, 2例 は開胸開腹で手術されたが, 術後合併症は1例に創感染を認めたのみであった. 原発性腫瘍例は全例術後再発を認めていないが, 転移性腫瘍の3例は全例, 術後10ヶ月以内に再発死した. 以上の結果は機能性副腎腫瘍でも偶然発見されるまで診断されない場合が多いことを示唆しており, 臨床症状を注意深く検討し常に副腎腫瘍の可能性を考慮にいれることが肝要であると考えられる. また, 今回の結果より CT が副腎腫瘤の診断において重要な位置を占めるものと考えられた. なお, 転移性副腎腫瘍に対する手術療法は今回の検討ではそれを積極的に支持する結果は得られず, 今後さらに検討を要する問題と思われる

    Tumor size before image-guided brachytherapy is an important factor of local control after radiotherapy for cervical squamous cell carcinoma: analysis in cases using central shielding

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    We analyzed the local control (LC) of cervical squamous cell carcinoma treated by computed tomography (CT)-based image-guided brachytherapy (IGBT) using central shielding (CS). We also examined the value of tumor diameter before brachytherapy (BT) as a factor of LC. In total, 97 patients were analyzed between April 2016 and March 2020. Whole-pelvic (WP) radiotherapy (RT) with CS was performed, and the total pelvic sidewall dose was 50 or 50.4 Gy; IGBT was delivered in 3-4 fractions. The total dose was calculated as the biologically equivalent dose in 2 Gy fractions, and distribution was modified manually by graphical optimization. The median follow-up period was 31.8 months (6.3-63.2 months). The 1- and 2-year LC rates were 89% and 87%, respectively. The hazard ratio was 10.11 (95% confidence interval: 1.48-68.99) for local recurrence in those with a horizontal tumor diameter >= 4 cm compared to those with = 4 cm, different treatment strategies such as employing interstitial-BT for dose escalation may be necessary

    Outcomes of solitary postoperative recurrence of esophageal squamous cell carcinoma diagnosed with FDG-PET/CT and treated with definitive radiation therapy

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    Background Surgical resection of esophageal cancer is frequently performed to achieve a complete cure. However, the postoperative recurrence rate is 36.8–42.5%, leading to poor prognosis. Radiation therapy has been used to treat recurrences; solitary recurrence has been proposed as a prognostic factor for radiation therapy, though its significance is unclear. 18F-fluorodeoxyglucose positron emission tomography is a highly accurate diagnostic modality for esophageal cancer. This retrospective study aimed to analyze the outcomes of solitary postoperative recurrences of esophageal squamous cell carcinoma diagnosed with 18F-fluorodeoxyglucose positron emission tomography and treated with definitive radiation therapy. Methods We examined 27 patients who underwent definitive radiation therapy for single or multiple postoperative recurrences of esophageal squamous cell carcinoma between May 2015 and April 2021. 18F-fluorodeoxyglucose positron emission tomography/computed tomography was performed within 3 months before the commencement of radiation therapy. Kaplan–Meier, univariate, and multivariate analyses were performed to examine the overall survival and identify potential prognostic factors. Results The 1-, 2-, and 3-year overall survival rates were 85.2%, 62.6%, and 47.3%, respectively, and solitary recurrence was the only significant factor associated with overall survival (P = 0.003). The 1-, 2-, and 3-year overall survival rates in patients with solitary recurrence were 91.7%, 80.2%, and 80.2%, respectively, and in patients with multiple recurrences they were 80.0%, 50.3%, and 25.1%, respectively. Multivariate analysis also showed solitary recurrence as a significant factor for overall survival. Conclusions When diagnosed with 18F-fluorodeoxyglucose positron emission tomography/computed tomography, solitary recurrence appears to have a more favorable prognosis than multiple recurrences
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