Dielectric function, critical points, and Rydberg exciton series of WSe2 monolayer

The complex dielectric function ([Formula: see text]) of WSe₂ monolayer grown by atomic layer deposition is investigated using spectroscopic ellipsometry. Band structure parameters are obtained by standard line-shape analysis of the second-energy-derivative of [Formula: see text] spectra. The fundamental band gap is observed at 2.26 eV, corresponds to transition between valence band (VB) maximum at the K point and conduction band (CB) minimum at Q point in the Brillouin zone (BZ). Two strong so-called A and B excitonic peaks in [Formula: see text] spectra originate from vertical transitions from spin-orbit split (0.43 eV) VB to CB at K point of the BZ. Binding energies of A and B exactions are 0.71 and 0.28 eV, respectively. Well resolved five excited excitons states has been detected within the spectral region between A and B. Energy profile of the Rydberg series shows significant deviation from the hydrogenic behavior, discussed in connection with the 2D hydrogen model. Results presented here will improve our understanding about the optical response of 2D materials and will help to design better optoelectronic applications and validate theoretical considerations.

Design and Rationale for comParison Between ticagreLor and clopidogrEl on mIcrocirculation in Patients with Acute cOronary Syndrome Undergoing Percutaneous Coronary Intervention (PLEIO) Trial

It has been previously demonstrated that ticagrelor can reduce mortality compared to clopidogrel in acute coronary syndrome (ACS) patients. However, the mechanism for this mortality reduction remains uncertain. The objective of the present study is to assess the impact of chronic ticagrelor treatment on microvascular circulation. A total of 120 participants aged 20–85 years with clinical diagnosis of ACS will be randomized in a 1:1 fashion to the following two groups: ticagrelor 90 mg twice daily; clopidogrel 75 mg once daily. To evaluate the status of microcirculation, the primary end point is coronary microvascular dysfunction measured using an index of microcirculatory resistance (IMR) at 6 months after receiving the study agent. The purpose of this trial is to investigate whether ticagrelor, beyond its antiplatelet efficacy, could improve coronary microcirculation more effectively than clopidogrel for patients with ACS.

A formulated red ginseng extract inhibits autophagic flux and sensitizes to doxorubicin-induced cell death

Background

Ginseng is believed to have antitumor activity. Autophagy is largely a prosurvival cellular process that is activated in response to cellular stressors, including cytotoxic chemotherapy; therefore, agents that inhibit autophagy can be used as chemosensitizers in cancer treatment. We examined the ability of Korean Red Ginseng extract (RGE) to prevent autophagic flux and to make hepatocellular carcinoma (HCC) cells become more sensitive to doxorubicin.

Methods

The cytotoxic effects of total RGE or its saponin fraction (RGS) on HCC cells were examined by the lactate dehydrogenase assay in a dose- or time-dependent manner. The effect of RGE or RGS on autophagy was measured by analyzing microtubule-associated protein 1A/1B-light chain (LC)3-II expression and LC3 puncta formation in HCC cells. Late-stage autophagy suppression was tested using tandem-labeled green fluorescent protein (GFP)-monomeric red fluorescent protein (mRFP)-LC3.

Results

RGE markedly increased the amount of LC3-II, but green and red puncta in tandem-labeled GFP-mRFP-LC3 remained colocalized over time, indicating that RGE inhibited autophagy at a late stage. Suppression of autophagy through knockdown of key ATG genes increased doxorubicin-induced cell death, suggesting that autophagy induced by doxorubicin has a protective function in HCC. Finally, RGE and RGS markedly sensitized HCC cells, (but not normal liver cells), to doxorubicin-induced cell death.

Conclusion

Our data suggest that inhibition of late-stage autophagic flux by RGE is important for its potentiation of doxorubicin-induced cancer cell death. Therapy combining RGE with doxorubicin could serve as an effective strategy in the treatment of HCC.

Catheter probe endoscopic ultrasonography by using cold lubricating jelly-filled method for esophageal subepithelial tumors

Catheter probe endoscopic ultrasonography (C-EUS) by ultrasonographic jelly-filled method has been used to evaluate esophageal subepithelial tumors (SETs). Ultrasonographic jelly is safe on the skin, but its internal safety has not been demonstrated. The jelly stored at room temperature is easily injected into the esophagus through the instrument channel of the endoscope. However, using jelly stored at room temperature remains problematic because the jelly is drained rapidly. We used cold lubricating jelly and an intravenous extension tube to resolve these problems. In this study, we evaluated the safety and efficacy of cold lubricating jelly-filled method. The medical records of patients who underwent C-EUS by using water or cold lubricating jelly-filled method for esophageal SETs from March 2013 to September 2016 in Gangneung Asan hospital were reviewed. Clinical characteristics and EUS findings were evaluated retrospectively. Image quality and procedure time between water and cold lubricating jelly-filled method were compared retrospectively. This study included 138 patients (74 males, 64 females) with esophageal SET with a mean age of 57.1 ± 11.1 years. Thirty-four patients had lesions in the upper esophagus, 58 patients had lesions in the middle esophagus, and 46 patients had lesions in the lower esophagus. The EUS diagnoses were leiomyoma (82.6%), hemangioma (4.3%), extrinsic compressive lesion (3.6%), granulosa cell tumor (2.9%), ectopic calcification (1.4%), cyst (1.4%), lipoma (0.7%), varix (0.7%), and inconclusive lesion (2.2%). The mean image score in the cold lubricating jelly filled-method group was higher than that in the water-filled method group (3.2 ± 0.7 vs. 2.8 ± 0.7, P = 0.002). The procedure time in the cold lubricating jelly filled-method group was shorter than that in the water-filled method group (10 minutes 27 seconds ± 4 minutes 22 seconds versus 13 minutes 20 seconds ± 6 minutes 20 seconds, P = 0.045). No procedure-related complication was observed. C-EUS using the cold lubricating jelly-filled method seems to provide better image quality and shorter procedure time compared with C-EUS using the water-filled method.

Development of a simple computerized torsion test to quantify subjective ocular torsion

PurposeThe double Maddox-rod test (DMRT) and Lancaster red-green test (LRGT) are the most widely used tests worldwide to assess subjective ocular torsion. However, these tests require equipment and the quantified results of ocular torsion are only provided in rough values. Here we developed a novel computerized torsion test (CTT) for individual assessment of subjective ocular torsion and validated the reliability and accuracy of the test compared with those of the DMRT and LRGT.MethodsA total of 30 patients with cyclovertical strabismus and 30 controls were recruited. The CTT was designed using Microsoft Office PowerPoint. Subjects wore red-green filter spectacles and viewed gradually tilted red and cyan lines on an LCD monitor and pressed the keyboard to go through the slides, until both lines seemed parallel. All subjects underwent the CTT, DMRT, and LRGT. Intraclass correlation coefficients and Bland-Altman plots were analyzed to assess the acceptability of the CTT compared with that of the DMRT.ResultsBoth the DMRT and CTT showed no significant test-retest differences in the strabismus and control groups. The DMRT and CTT results demonstrated an acceptable agreement. The reliability of the CTT was better than that of the DMRT. The LRGT showed low sensitivity for the detection of ocular torsion compared with the DMRT (40.0%) and CTT (39.1%).ConclusionOur results suggest that the assessment of subjective ocular torsion using the CTT based on PowerPoint software is simple, reproducible, and accurate and can be applied in clinical practice.

The unique spliceosome signature of human pluripotent stem cells is mediated by SNRPA1, SNRPD1, and PNN

Spliceosomes are the core host of pre-mRNA splicing, allowing multiple protein isoforms to be produced from a single gene. Herein, we reveal that spliceosomes are more abundant in human pluripotent stem cells (hPSs), including human embryonic stem cells (hESs) and human induced pluripotent stem cells (hiPSs), than non-hPSs, and their presence is associated with high transcriptional activity. Supportively, spliceosomal components involved in the catalytically active pre-mRNA splicing step were mainly co-localized with hPS spliceosomes. By profiling the gene expression of 342 selected splicing factors, we found that 71 genes were significantly altered during the reprogramming of human somatic cells into hiPSs. Among them, SNRPA1, SNRPD1, and PNN were significantly up-regulated during the early stage of reprogramming, identified as hub genes by interaction network and cluster analysis. SNRPA1, SNRPD1, or PNN depletion led to a pronounced loss of pluripotency and significantly blocked hiPS generation. SNRPA1, SNRPD1, and PNN co-localized with the hPS spliceosomes, physically interacted with each other, and positively influenced the appearance of hPS spliceosomes. Our data suggest that SNRPA1, SNRPD1, and PNN are key players in the regulation of pluripotency-specific spliceosome assembly and the acquisition and maintenance of pluripotency.

Left Ventricular Functional Parameters and Geometric Patterns in Korean Adults on Coronary CT Angiography with a 320-Detector-Row CT Scanner

OBJECTIVE

To assess the normal reference values of left ventricle (LV) functional parameters in Korean adults on coronary CT angiography (CCTA) with a 320-detector-row CT scanner, and to analyze sex-related differences and correlations with various clinical characteristics.

MATERIALS AND METHODS

This study retrospectively enrolled 172 subjects (107 men and 65 women; age, 58 ± 10.9 years; body surface area [BSA], 1.75 ± 0.2 m²) who underwent CCTA without any prior history of cardiac disease. The following parameters were measured by post-processing the CT data: LV volume, LV functional parameters (ejection fraction, stroke volume, cardiac output, etc.), LV myocardial mass, LV inner diameter, and LV myocardial thickness (including septal wall thickness [SWT], posterior wall thickness [PWT], and relative wall thickness [RWT = 2 × PWT / LV inner diameter]). All of the functional or volumetric parameters were normalized using the BSA. The general characteristics and co-morbidities for the enrolled subjects were recorded, and the correlations between these factors and the LV parameters were then evaluated.

RESULTS

The LV myocardial thickness (SWT, 1.08 ± 0.18 cm vs. 0.90 ± 0.17 cm, p < 0.001; PWT, 0.91 ± 0.15 cm vs. 0.78 ± 0.10 cm, p < 0.001; RWT, 0.38 ± 0.08 cm vs. 0.33 ± 0.05 cm, p < 0.001), LV volume (LV end-diastolic volume, 112.9 ± 26.1 mL vs. 98.2 ± 21.0 mL, p < 0.001; LV end-systolic volume, 41.7 ± 14.7 mL vs. 33.7 ± 12.2 mL, p = 0.001) and mass (145.0 ± 29.1 g vs. 107.9 ± 20.0 g, p < 0.001) were significantly greater in men than in women. However, these differences were not significant after normalization using BSA, except for the LV mass (LV mass index, 79.6 ± 14.0 g/m² vs. 66.2 ± 11.0 g/m², p < 0.001). The cardiac output and ejection fraction were not significantly different between the men and women (cardiac output, 4.3 ± 1.0 L/min vs. 4.2 ± 0.9 L/min, p = 0.452; ejection fraction, 63.4 ± 7.7% vs. 66.4 ± 7.6%, p = 0.079). Most of the LV parameters were positively correlated with BSA, body weight, and total Agatston score.

CONCLUSION

This study provides sex-related reference values and percentiles for LV on cardiac CT and should assist in interpreting results.

Schwann Cell Precursors from Human Pluripotent Stem Cells as a Potential Therapeutic Target for Myelin Repair

Schwann cells play a crucial role in successful nerve repair and regeneration by supporting both axonal growth and myelination. However, the sources of human Schwann cells are limited both for studies of Schwann cell development and biology and for the development of treatments for Schwann cell-associated diseases. Here, we provide a rapid and scalable method to produce self-renewing Schwann cell precursors (SCPs) from human pluripotent stem cells (hPSCs), using combined sequential treatment with inhibitors of the TGF-β and GSK-3 signaling pathways, and with neuregulin-1 for 18 days under chemically defined conditions. Within 1 week, hPSC-derived SCPs could be differentiated into immature Schwann cells that were functionally confirmed by their secretion of neurotrophic factors and their myelination capacity in vitro and in vivo. We propose that hPSC-derived SCPs are a promising, unlimited source of functional Schwann cells for treating demyelination disorders and injuries to the peripheral nervous system.

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hPSC-SCPs are highly expandable under chemically defined medium condition

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hPSC-SCPs can rapidly and efficiently differentiate into functional Schwann cells

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SCP-SCs myelinate axon and secrete various neurotrophic factors

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SCP-SCs promote axonal regeneration in sciatic nerve-damaged mice

Minimal pneumothorax with dynamic changes in ST segment similar to myocardial infarction

Pneumothorax can cause a variety of electrocardiographic changes. ST segment elevation, which is mainly observed in myocardial infarction, can also be induced by pneumothorax. The mechanism is presumed to be a decrease in cardiac output, due to increased intra-thoracic pressure. We encountered a patient with ST segment elevation with minimal pneumothorax. Coronary angiography with ergonovine provocation test and echocardiogram had normal findings. The ST segment elevation was normalized by decreasing the amount of pneumothorax. We reviewed the literature and present possible mechanisms for this condition.

Sterile Neutrino Search at the NEOS Experiment

An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3+1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin^{2}2θ_{14} is limited up to less than 0.1 for Δm_{41}^{2} ranging from 0.2 to 2.3 eV^{2} with a 90% confidence level.

Pro-fibrotic effects of PFKFB4-mediated glycolytic reprogramming in fibrous dysplasia

Fibrous dysplasia (FD) caused by a mosaic somatic mutation of GNAS is characterized by replacement of the affected bone with abnormal fibrous tissue. Herein, we present novel disease models for FD developed with pairs of isogenic wild-type and GNAS(R201H)-mutated induced pluripotent stem cells (iPSCs) and their derivative mesenchymal stem cells (MSCs). Both 2D and 3D MSC culture models for FD successfully reflect FD's typical molecular characteristics, such as enhanced cAMP level, PKA activity, CREB1 phosphorylation and the pathologic fibrotic phenotype. The fibrotic features of GNAS(R201H) FD model cells were closely linked to augmented glycolysis and depended on glycolytic PFKFB4 and the activation of pro-fibrotic TGFβ signalling. Either depletion of PFKFB4 or inhibition of glycolysis or TGFβ signalling potentially blocked fibrosis progression in GNAS(R201H) FD model cells. Our FD models could facilitate a better mechanistic understanding of FD and help develop effective therapeutics for FD and other fibrosis diseases.

Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment

The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3}  eV^{2}.

Nuclear Speckle-related Protein 70 Binds to Serine/Arginine-rich Splicing Factors 1 and 2 via an Arginine/Serine-like Region and Counteracts Their Alternative Splicing Activity

Nuclear speckles are subnuclear storage sites containing pre-mRNA splicing machinery. Proteins assembled in nuclear speckles are known to modulate transcription and pre-mRNA processing. We have previously identified nuclear speckle-related protein 70 (NSrp70) as a novel serine/arginine (SR)-related protein that co-localizes with classical SR proteins such as serine/arginine-rich splicing factor 1 (SRSF1 or ASF/SF2) and SRSF2 (SC35). NSrp70 mediates alternative splice site selection, targeting several pre-mRNAs, including CD44 exon v5. Here we demonstrated that NSrp70 interacts physically with two SR proteins, SRSF1 and SRSF2, and reverses their splicing activity in terms of CD44 exon v5 as exon exclusion. The NSrp70 RS-like region was subdivided into three areas. Deletion of the first arginine/serine-rich-like region (RS1) completely abrogated binding to the SR proteins and to target mRNA and also failed to induce splicing of CD44 exon v5, suggesting that RS1 is critical for NSrp70 functioning. Interestingly, RS1 deletion also resulted in the loss of NSrp70 and SR protein speckle positioning, implying a potential scaffolding role for NSrp70 in nuclear speckles. NSrp70 contains an N-terminal coiled-coil domain that is critical not only for self-oligomerization but also for splicing activity. Consistently, deletion of the coiled-coil domain resulted in indefinite formation of nuclear speckles. Collectively, these results demonstrate that NSrp70 acts as a new molecular counterpart for alternative splicing of target RNA, counteracting SRSF1 and SRSF2 splicing activity.

Comparison of Prolonged Atrial Electromechanical Delays with Different Definitions in the Discrimination of Patients with Non-Valvular Paroxysmal Atrial Fibrillation

Background and Objectives

Previous studies have evaluated atrial electromechanical delays (AEMDs) with a number of different definitions to discriminate patients with paroxysmal atrial fibrillation (PAF) from controls without PAF. However, their discriminative values for PAF have not previously been directly compared.

Subjects and Methods

A total of 65 PAF patients and 130 control subjects matched for age, sex, history of hypertension, and diabetes mellitus were selected. The AEMDi and AEMDp were defined as the time intervals from the initiation of the P wave on the surface electrocardiogram to the initiation and peak of the late diastolic transmitral inflow on pulsed wave Doppler images, respectively. The AEMDim and AEMDpm were defined as the time intervals from the initiation of the P wave on the surface electrocardiogram to the initiation and peak of the late diastolic lateral mitral annular motion on tissue Doppler images, respectively.

Results

There were no significant differences in the clinical characteristics between the two groups. All 4 AEMDs were consistently longer in the PAF group, and proven effective to differentiate the PAF patients from the controls. The AEMDi measurement had a larger area under the curve (AUC) than the other AEMDs, left atrial volume index, and P wave amplitude. However, the AEMDp, AEMDim, and AEMDpm measurements had AUCs similar to those of the left atrial volume index and P wave amplitude.

Conclusion

The findings suggest that the AEMDi is better than the other AEMDs for the discrimination of PAF patients from the controls.

A Rare Cause of Secondary Hypertension in A Young Adult

Reninoma is a rare, renin-secreting, benign renal neoplasm that can cause secondary hypertension. We report a case of a 21-year-old man who suffered from progressively worsening headache for 2 months with a history of hypertension for 7 years. Laboratory studies showed normal potassium level, increased basal plasma renin activity, and normal serum aldosterone level. Abdominal computed tomography and magnetic resonance imaging revealed a small mass in the middle region of the right kidney. Partial nephrectomy was performed; immunohistochemical results demonstrated typical features of reninoma. Postoperatively, blood pressure and potassium level were normal at the 2-month follow-up.

Ventricular Septal Rupture in a Case Suspected as Stress Induced Cardiomyopathy

An 87-year-old woman with continuous chest discomfort was referred to our hospital. ST-segment elevation in lead V_1-4 was detected on electrocardiography and ventricular septal rupture (VSR) was observed on echocardiography. Post-acute myocardial infarction (AMI) VSR was suspected and she underwent emergency cardiac catheterization. However, coronary angiography showed normal coronary artery. On the fourth day after admission, the patient died. We suspect that VSR was developed by stress induced cardiomyopathy, not by AMI.

Harmonizing Optimal Strategy for Treatment of coronary artery diseases--comparison of REDUCtion of prasugrEl dose or POLYmer TECHnology in ACS patients (HOST-REDUCE-POLYTECH-ACS RCT): study protocol for a randomized controlled trial

Background

Antiplatelet treatment is an important component in optimizing the clinical outcomes after percutaneous coronary intervention (PCI) especially in patients with acute coronary syndrome (ACS). Prasugrel, which is a new P2Y12 inhibitor, has been confirmed as efficacious in a large trial in Western countries, and a similar trial is also to be launched in Asian countries. Although a 60-mg loading dose of prasugrel followed by 10 mg per day should be acceptable, there have been no data regarding the optimal dose in Asian patients. Furthermore, serum levels of prasugrel and the rates of platelet inhibition are known to be higher in Asians than Caucasians with the same dose of the drug.

Polymer, a key component of drug-eluting stents (DES), has been suggested as the cause of inflammation leading to late complications, and has driven many companies to develop biodegradable-polymer DES. Currently, there are limited data regarding the head-to-head comparison between BP-BES and the biostable polymer CoCr-EES or the newest platinum-chromium everolimus-eluting stent (PtCr-EES). Furthermore, the polymer issue may be more important in ACS where there is ruptured thrombotic plaque where polymer-induced inflammation may affect the local milieu of the stented artery.

Therefore, the present study dedicated only to ACS patients, will offer important information on the optimal prasugrel dose in the Asian population by comparing a 10-mg versus a 5-mg maintenance dose beyond 1 month after PCI, as well as giving important insight into the polymer issue by comparing BP-BES versus biostable-polymer PtCr-EES.

Method/Design

Harmonizing Optimal Strategy for Treatment of coronary artery diseases – comparison of REDUCtion of prasugrEl dose or POLYmer TECHnology in ACS patients (HOST-REDUCE-POLYTECH-ACS) trial is a multicenter, randomized and open-label clinical study with a 2 × 2 factorial design, according to the type of stent (PtCr-EES versus BP-BES) and prasugrel maintenance dose (5 mg versus 10 mg), to demonstrate non-inferiority of PtCr-EES relative to BP-BES or the reduced prasugrel dose relative to conventional dose in an Asian all-comers PCI population presenting with ACS. Approximately 3400 patients will undergo prospective, random assignment separately to either stent or prasugrel arm (1:1 ratio, respectively). When the patients have contraindications to prasugrel, they are categorized into an antiplatelet observation group after stent-randomization. The primary endpoint is the patient-oriented composite outcome, which is a composite of all-cause mortality, any myocardial infarction (MI), any repeat revascularization in the stent arm at 12 months after index PCI. In the prasugrel arm, primary endpoint is any major adverse cardiovascular event, which is a composite of all-cause mortality, any MI, any stent thrombosis (Academic Research Consortium (ARC)-defined), any repeat revascularization, stroke, or bleeding (BARC class ≥ 2).

Discussion

The HOST-REDUCE-POLYTECH-ACS RCT is the first study exploring the optimal maintenance dose of prasugrel beyond 1 month after PCI for ACS in Asian all-comers. In addition, this is the largest study dedicated only to ACS patients to evaluate the polymer issue in the situation of ACS by directly comparing biostable-polymer PtCr-EES versus BP-BES.

Trial registration

ClinicalTrials.gov (ID: NCT02193971, 13 July 2014).