93 research outputs found

    Electronic interferometer capacitively coupled to a quantum dot

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    We theoretically study electron interference in a ballistic electronic interferometer capacitively coupled to a quantum dot. The visibility of the interference is reduced when the dot has degenerate ground states with different excess charges. The degree of the reduction depends on system parameters such as the strength of the capacitive coupling, and the dependence is analyzed in the regime where the dwell time of electrons in the dot is much longer than the electron flight time through the interferometry region coupled to the dot. The result is consistent with recent experimental data.Comment: 4 pages, 2 figure

    Nonequilibrium Dephasing in an Electronic Mach-Zehnder Interferometer

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    We study nonequilibrium dephasing in an electronic Mach-Zehnder interferometer. We demonstrate that the shot noise at the beam splitter of the interferometer generates an ensemble of nonequilibrium electron density configurations and that electron interactions induce configuration-specific phase shifts of an interfering electron. The resulting dephasing exhibits two characteristic features, a lobe pattern in the visibility and phase jumps of π\pi, in good agreement with experimental data.Comment: 4 pages, 3 figures; some typos are corrected; published versio

    Tumor suppressive role of sestrin2 during colitis and colon carcinogenesis

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    The mTOR complex 1 (mTORC1) and endoplasmic reticulum (ER) stress pathways are critical regulators of intestinal inflammation and colon cancer growth. Sestrins are stress-inducible proteins, which suppress both mTORC1 and ER stress; however, the role of Sestrins in colon physiology and tumorigenesis has been elusive due to the lack of studies in human tissues or in appropriate animal models. In this study, we show that human SESN2 expression is elevated in the colon of ulcerative colitis patients but is lost upon p53 inactivation during colon carcinogenesis. In mouse colon, Sestrin2 was critical for limiting ER stress and promoting the recovery of epithelial cells after inflammatory injury. During colitis-promoted tumorigenesis, Sestrin2 was shown to be an important mediator of p53’s control over mTORC1 signaling and tumor cell growth. These results highlight Sestrin2 as a novel tumor suppressor, whose downregulation can accelerate both colitis and colon carcinogenesis

    Breakage of a thoracic epidural catheter during its removal -A case report-

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    The breakage of an epidural catheter is a rare complication during the removal of a thoracic epidural catheter. There are many causes to breakage of an epidural catheter, such as the characteristics of the catheter itself, patient's factors (anatomy, position during insertion and removal of the catheter, and the BMI), and the difficulty of the procedure. Surgical removal is considered if there is a possibility that the retained catheter might cause neurological problems. We experienced a breakage of an epidural catheter during its removal, which led to surgical intervention. To prevent the catheter breakage during its removal, the catheter should be withdrawn without excessive tension. In addition, an understanding of the patient's anatomy is essential

    Ketamine use for endotracheal intubation in severe sepsis and septic shock

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    Objective. We conducted this study to evaluate the clinical outcomes of patients with severe sepsis and septic shock who were treated with ketamine for endotracheal intubation. Methods. A single-center, retrospective study was carried out to compare the outcomes of patients with severe sepsis and septic shock who received a ketamine or non-ketamine agent for rapid sequence intubation (RSI). We analyzed the sepsis registry for adult patients who presented to the emergency department (ED), met the criteria for severe sepsis or septic shock, and underwent endotracheal intubation between August 2008 and March 2014. Te primary outcome was 28-day mortality. We performed a multivariable logistic regression analysis to assess the association between ketamine use for intubation and 28-day mortality. Results. In all, 170 patients were intubated during the study period. Of the eligible patients, 95 received ketamine and 75 received a non-ketamine agent. Te 28-day mortality of the ketamine group was not signifcantly diferent from that of the nonketamine group (38% vs. 40%, respectively,P=0.78). Te unadjusted odds ratio (OR) of ketamine use for 28-day mortality was 0.92 (95% CI: 0.49–1.70, P=0.78). Te association remained insignifcant afer adjusting for age, gender, malignancy, initial lactate level on ED admission, time to frst antibiotic administration, Acute Physiology and Chronic Health Evaluation II score on admission day, and propensity score regarding ketamine use (adjusted OR: 1.09; 95% confdence interval [CI]: 0.49–2.40;P=0.84). Initial serum lactate on ED admission was the only signifcant predictive factor of 28-day mortality (adjusted OR: 1.23; 95% CI: 1.10–1.38; P<0.01). Conclusions. For patients with severe sepsis and septic shock who were intubated using RSI, we found no signifcant diference in 28-day mortality between those who received ketamine as a sedative agent and those who received alternative sedatives

    Analysis of the Monocyte Chemoattractant Protein 1 -2518 Promoter Polymorphism in Korean Patients with Alopecia Areata

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    Monocyte chemoattractant protein-1 (MCP-1) levels are increased in scalp lesions of patients with alopecia areata (AA), suggesting a role in the development of AA. Recently, a biallelic A/G polymorphism in the MCP-1 promoter at position -2518 has been found, influencing the level of MCP-1 expression in response to an inflammatory stimulus. We investigated whether the presence of these polymorphisms were associated with AA in Korean population. 145 Korean patients with AA, 246 healthy subjects without clinical evidence of AA were screened for genotype with a PCR-based assay. In the AA patients the frequency of the A and G alleles was 40.3 and 59.7%, respectively and the distribution of the A/A, A/G and G/G genotypes was 19.3, 42.1 and 38.6%, respectively. Amongst the controls the frequency of the A and G alleles was 39.8 and 60.2%, and the distribution of the A/A, A/G, G/G genotypes in the same group was 17.5, 44.7 and 37.8%, respectively. There was no significant difference in the allele frequencies and genotype distributions between the patients and the controls (p=0.889, p=0.848, respectively). Our data indicates that no association exists between the -2518A/G polymorphism of the MCP-1 gene and susceptibility to alopecia areata

    Delayed Primary Repair of Perforated Epiphrenic Diverticulum

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    A 68-yr-old man complaining of sudden, postprandial chest pain visited the emergency room. His symptom had been aggravated during the preceding two days. Upper gastrointestinal contrast study with gastrographin showed leakage of dye from the epiphrenic diverticulum in the lower third of the esophagus. The primary repair was urgently carried out. Upper gastrointestinal contrast study 14 days after operation revealed an esophageal leakage which was small and confined. The patient was managed with conservative treatments such as intravenous hyperali-mentation and broad-spectrum antibiotics. Forty-two days after the operation, a gastrographin swallow study showed the absence of leaks. This is the first report-ed case of a perforated epiphrenic esophageal diverticulum repaired by delayed primary repair in Korea

    A Call for a Rational Polypharmacy Policy: International Insights From Psychiatrists

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    OBJECTIVE: Recently, rational polypharmacy approaches have been proposed, regardless of the lower risk and cost of monotherapy. Considering monotherapy as first-line treatment and polypharmacy as rational treatment, a balanced attitude toward polypharmacy is recommended. However, the high prevalence of polypharmacy led the Japanese government to establish a polypharmacy reduction policy. Based on this, the association between the policy and psychiatrists' attitude toward polypharmacy has been under debate. METHODS: We developed an original questionnaire about Psychiatrists' attitudes toward polypharmacy (PAP). We compared the PAP scores with the treatment decision-making in clinical case vignettes. Multiple regression analyses were performed to quantify associations of explanatory variables including policy factors and PAP scores. The anonymous questionnaires were administered to psychiatrists worldwide. RESULTS: The study included 347 psychiatrists from 34 countries. Decision-making toward polypharmacy was associated with high PAP scores. Multiple regression analysis revealed that low PAP scores were associated with the policy factor (β=-0.20, p=0.004). The culture in Korea was associated with high PAP scores (β=0.34, p<0.001), whereas the culture in India and Nepal were associated with low scores (β=-0.15, p=0.01, and β=-0.17, p=0.006, respectively). CONCLUSION: Policy on polypharmacy may influence psychiatrists' decision-making. Thus, policies considering rational polypharmacy should be established
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