Optical transitions between Landau levels: AA-stacked bilayer graphene

The low-frequency optical excitations of AA-stacked bilayer graphene are investigated by the tight-binding model. Two groups of asymmetric LLs lead to two kinds of absorption peaks resulting from only intragroup excitations. Each absorption peak obeys a single selection rule similar to that of monolayer graphene. The excitation channel of each peak is changed as the field strength approaches a critical strength. This alteration of the excitation channel is strongly related to the setting of the Fermi level. The peculiar optical properties can be attributed to the characteristics of the LL wave functions of the two LL groups. A detailed comparison of optical properties between AA-stacked and AB-stacked bilayer graphenes is also offered. The compared results demonstrate that the optical properties are strongly dominated by the stacking symmetry. Furthermore, the presented results may be used to discriminate AABG from MG, which can be hardly done by STM

Acute immune thrombocytopenic purpura in an adolescent with 2009 novel H1N1 influenza A virus infection

AbstractAlthough both leukopenia and thrombocytopenia are not uncommon hematological findings among patients with novel 2009 H1N1 influenza virus infection, immune thrombocytopenic purpura has rarely been shown to be associated with this novel influenza A infection. Here, we describe a previously healthy adolescent who presented with fever, influenza-like symptoms and acute onset of generalized petechiae and active oral mucosa bleeding on the third day of his illness. Severe leukopenia and thrombocytopenia were found. There was neither malignancy nor blast cells found by bone marrow aspiration. Real-time reverse transcriptase polymerase chain reaction was positive for novel 2009 H1N1 influenza infection. Novel influenza-associated atypical immune thrombocytopenic purpura was diagnosed. The patient recovered uneventfully after oseltamivir and methylprednisolone therapy

Novel technique of neovagina creation with uterine serosa in the treatment of vaginal agenesis associated with mullerian agenesis

AbstractObjectiveOur aim was to create a neovagina with the least surgical morbidity and the best functional outcome.Materials and methodsWe hereby describe a new technique (Lee's neovaginoplasty) using a combined laparoscopic and vaginal approach in the creation of a neovagina using the uterine serosa layer from the rudimentary uterus and the peritoneum as a graft to line the vagina. This procedure was performed in three patients who were followed-up for a duration of 4 months to 2 years. Vaginal dilation was maintained with a vaginal mold daily for 3 months and three to four times a week thereafter.ResultsAdequate vaginal length of 6-7 cm and width of 2.5 cm was achieved postoperatively. There were no surgical complications and postoperative recovery was fast. Vaginal examination 1 month later showed healthy vaginal tissue with no necrosis or infection. Long-term follow-up did not show any shortening or stenosis of the vagina. Patients were able to have satisfactory sexual intercourse with no pain.ConclusionThe laparoscopic-vaginal approach of using a uterine serosa and peritoneal graft for creation of a neovagina is a simple and effective approach with minimal surgical morbidity that can create a passageway for satisfactory intercourse

The application of infrared thermography in evaluation of patients at high risk for lower extremity peripheral arterial disease

ObjectiveWe investigated the usefulness of infrared thermography in evaluating patients at high risk for lower extremity peripheral arterial disease (PAD), including severity, functional capacity, and quality of life.MethodsA total of 51 patients (23 males; age 70 ± 9.8 years) were recruited. They completed three PAD-associated questionnaires, including walking impairment, vascular quality of life, and 7-day physical activity recall questionnaires before a 6-minute walking test (6MWT). Ankle-brachial index (ABI) and segmental pressure were analyzed for PAD diagnosis and stenotic level assessment. The cutaneous temperature at shin and sole were recorded by infrared thermography before and after the walk test. Detailed demographic information and medication list were obtained.ResultsTwenty-eight subjects had abnormal ABI (ABI <1), while PAD was diagnosed in 20. No subjects had non-compressible artery (ABI >1.3). Demographic profiles and clinical parameters in PAD and non-PAD patients were similar, except for age, smoking history, and hyperlipidemia. PAD patients walked shorter distances (356 ± 102 m vs 218 ± 92 m; P < .001). Claudication occurred in 14 patients, while seven failed in completing the 6MWT. The rest temperatures were similar in PAD and non-PAD patients. However, the post-exercise temperature dropped in the lower extremities with arterial stenosis, but was maintained or elevated slightly in the extremities with patent arteries (temperature changes at sole in PAD vs non-PAD patients: −1.25 vs −0.15°C; P < .001). The exercise-induced temperature changes at the sole were not only positively correlated with the 6MWD (Spearman correlation coefficient = 0.31, P = .03), but was also correlated with ABI (Spearman correlation coefficient = 0.48, P < .001) and 7-day physical activity recall scores (Spearman correlation coefficient = 0.30, P = .033).ConclusionBy detecting cutaneous temperature changes in the lower extremities, infrared thermography offers another non-invasive, contrast-free option in PAD evaluation and functional assessment

Liver angiosarcoma, a rare liver malignancy, presented with intraabdominal bleeding due to rupture- a case report

Liver angiosarcoma is a rare disease, however it still ranks as the third of most common primary liver maligancies. The prognosis of liver angiosarcoma is very poor with almost all patients with this kind of disease die within 2 years after diagnosis. No specific symptoms and signs are closely associated with this disease. Here, we report a case presenting shock status at first due to rupture of liver angiosarcoma- induced internal bleeding. After emergent transarterial embolization (TAE), she received partial hepatectomy two weeks later. 4 months after operation, she is still with a good performance status without obvious recurrence or metastasis identified

The Incremental Diagnostic Performance of Coronary Computed Tomography Angiography Added to Myocardial Perfusion Imaging in Patients with Intermediate-to-High Cardiovascular Risk

Purpose: Several studies have suggested that a combined approach of stress myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) can provide diagnostic results with excellent accuracy. We aimed to explore whether the addition of CCTA to stress MPI provides incremental diagnostic value in intermediate-to-high cardiovascular risk patients. Methods: A total of 106 consecutive patients (93 male, 65 ± 10.4 years) underwent coronary artery calcium scoring (CACS), CCTA and 201 Thallium stress MPI before coronary angiography was reviewed. Thirty-seven patients (34.9%) had a history of proven coronary artery disease (CAD) or revascularization procedures, and four had documented non-significant CAD (3.8%). The remaining patients consisted of 17 (16.0%) classified as intermediate, and 48 (45.3%) as the high-risk groups. Results: Obstructive CAD was diagnosed by invasive coronary angiography in 88 patients with 161 vessels. The sensitivity and specificity in a patient-based analysis for obstructive CAD were 99% and 17% for CCTA, 80% and 50% for MPI and 91% and 67% for the combined method, respectively. The per-vessel diagnostic sensitivity and specificity were 95% and 54% for CCTA, 59% and 75% for MPI and 84% and 76% for the combined method. There were significant differences (p &lt; 0.05) when comparing the combined method with MPI or CCTA by areas under the curve in a patient-or vessel-based analysis. However, CACS of 400 or more could not further stratify the patients with obstructive CAD. Conclusions: CCTA, not CACS, provided additional diagnostic values to stress MPI in patients with intermediateto-high cardiovascular risk

Early combined treatment with sildenafil and adipose-derived mesenchymal stem cells preserves heart function in rat dilated cardiomyopathy

<p>Abstract</p> <p>Background</p> <p>We investigated whether early combined autologous adipose-derived mesenchymal stem cell (ADMSC) and sildenafil therapy offers an additive benefit in preserving heart function in rat dilated cardiomyopathy (DCM).</p> <p>Methods</p> <p>Adult Lewis rats (n = 8 per group) were divided into group 1 (normal control), group 2 (saline-treated DCM rats), group 3 [2.0 × 10⁶ADMSC implanted into left ventricular (LV) myocardium of DCM rats], group 4 (DCM rats with sildenafil 30 mg/kg/day, orally), and group 5 (DCM rats with combined ADMSC-sildenafil). Treatment was started 1 week after DCM induction and the rats were sacrificed on day 90.</p> <p>Results</p> <p>The results showed that mitochondrial protein expressions of connexin43 and cytochrome-C were lowest in group 2, and lower in groups 3 and 4 than in group 5 (p < 0.002). Conversely, oxidative index was highest in group 2, and also higher in groups 3 and 4 than in group 5 (p < 0.0003). The mRNA expressions of interleukin (IL)-10, Gro/IL-8, endothelial nitric oxide synthase, and Bcl-2 were lowest in group 2, and lower in groups 3 and 4 compared with group 5 (p < 0.0001). The mRNA expressions of matrix metalloproteinase-9, Bax, caspase 3, and stromal-cell derived factor-1α were highest in group 2, and higher in groups 3 and 4 than in group 5 (p < 0.0004). Apoptosis and fibrosis in LV myocardium were most prominent in group 2 and higher in groups 3 and 4 than in group 5, whereas angiogenesis and LV ejection fraction were lowest in group 2 and lower in groups 3 and 4 than in group 5 (p < 0.003).</p> <p>Conclusion</p> <p>Early combined ADMSC/sildenafil is superior to either treatment alone in preserving LV function.</p