[Effects of long non-coding RNA FLJ37505 on the proliferation and migration of bladder cancer cells]

Objective: To examine the expression of long-chain non-coding RNA (lncRNA) FLJ37505 in bladder cancer tissues and cell lines, and to analyze the molecular mechanism of FLJ37505 to inhibit the proliferation and migration of bladder cancer cells. Methods: Quantitative Real-time PCR(qPCR) was used to analyze the relative expression of FLJ37505 in 63 cases of bladder cancer tissues and bladder cancer cell lines (T24, J82, 5637, BIU-87 and UM-UC-3). The bladder cancer cell lines with the least expression of FLJ37505 were divided into control group (transfected with blank plasmid) and FLJ37505 group (transfected with a plasmid carrying the FLJ37505 sequence) according to random number method. MTS assay and scratch assay were used to detect the effect of up-regulation of FLJ37505 expression on cell proliferation and migration. Bioinformatics predicts the target gene of FLJ37505. The dual luciferase reporter system detects the binding of FLJ37505 to the target gene. qPCR and Western blot were used to detect the effect of FLJ37505 on the expression of target gene. Results: Compared with adjacent tissues, FLJ37505 expression was lower in bladder cancer tissue [(4.90±0.79) vs (0.89±0.28), P<0.05]. Compared with human normal bladder tubular epithelial cells, the expression of FLJ37505 was lower in bladder cancer cell lines (P<0.05), and FLJ37505 has the lowest expression in UM-UC-3 cells (P<0.01). Compared with the control group, the expression of FLJ37505 in UM-UC-3 cells of FLJ37505 group was higher [(0.79±0.04) vs (9.92±1.17), P<0.01]. Compared with the control group, the proliferation ability of UM-UC-3 cells in FLJ37505 group was inhibited (P<0.05), and the cell migration ability was also inhibited (P<0.01). Bioinformatics showed that the target gene of FLJ37505 is miR-203a-3p, and the target gene of miR-203a-3p is inositol polyphosphate 4-phosphatase typeⅡ (INPP4B). The dual luciferase reporter gene system showed that FLJ37505 could complement the miR-203a-3p (P<0.01), and miR-203a-3p could complement the INPP4B mRNA (P<0.01). Compared with the control group, the expression of miR-203a-3p was lower [(1.00±0.05) vs (0.20±0.02), P<0.01], the expression of INPP4B in mRNA and protein levels of UM-UC-3 cells in FLJ37505 group was significantly increased (all P<0.01). Conclusions: The expression of FLJ37505 was significantly decreased in bladder cell carcinoma and bladder cancer cells. Up-regulation of FLJ37505 significantly inhibits the proliferation and migration of bladder cell carcinoma UM-UC-3 cells, and the mechanism might be up-regulating the expression of the INPP4B gene by adsorbing miR-203a-3p.

O-GlcNAcylation promotes malignant phenotypes of bladder cancer cells

O-GlcNAcylation (O-GlcNAc) is a posttranslational modification that is mediated by O-GlcNAc-transferase (OGT) and reversed by O-GlcNAcase (OGA). Increasing evidence indicates that protein O-GlcNAcylation is increased in various types of cancer. In the present study, we aimed to evaluate the expression and function of both OGT and OGA in bladder cancer cells in vitro and in vivo. Expression data of OGT and OGA at the mRNA level was obtained from the Oncomine database. Effects of OGT and OGA on cell proliferate, invasive, and migratory abilities were assessed using MTT, wound healing, cell invasive assay, and cell cycle analysis. In vivo assay was also performed in nude mice. The results revealed that the expression of OGT in bladder cancer tissues was higher than that of normal tissues, while the OGA level was found to be lower in cancer tissues. We also found that knockdown of OGT could inhibit cell proliferation, migration, invasion, and induce cell cycle arrest, while these are reversed when OGA is inhibited. We also observed that O-GlcNAcylation could promote tumor formation in vivo, compared with a negative control. In summary, this study describes the oncogenic role of O-GlcNAcylation in bladder cancer cells.

Decreased expression of SorCS1 in colorectal cancer: An independent predictor of poor prognosis

Previously, we identified that sortilin related VPS10 domain containing receptor 1 (SorCS1) was hypermethylated in colorectal cancer (CRC) tissues. Here, we aimed to investigate the association between CRC and SorCS1. DNA methylation was determined by methylation-specific polymerase chain reaction (MSP) or quantitative real-time methylation analysis (MethyLight). Colorectal cancer tissue specimens from 239 patients that had undergone surgical treatment were evaluated using immunohistochemistry (IHC) analysis for the expression of SorCS1 and correlated with clinicopathological variables and prognosis. We found that SorCS1 was hypermethylated in CRC cell lines and 67.5% (27/40) CRC tumor tissues. The loss of SorCS1 mRNA (p<0.001) and protein expression (p=0.033) were highly correlated with promoter methylation. In addition, SorCS1 expression was significantly increased in younger patients (p=0.006), low CEA level (p<0.001) and pT1-2 stage (p=0.005). Survival analysis revealed that decreased expression of SorCS1 was an independent factor for predicting the increased risk of recurrence (p=0.024) and poor overall survival (p=0.006). Subgroup analysis for CEA level, pT and pN classifications showed that SorCS1 retained its stratified significance only in patients with low CEA level, pT3-4 tumors and pN1-2 lymph node status. Our findings suggest that SorCS1 is epigenetically inactivated in a substantial fraction of CRC, and its expression may be a promising prognostic factor in CRC patients.

P6550Right ventricular apical pacing vs. non-right ventricular apical pacing induced tricuspid regurgitation: implication of 3D echocardiographic location of leads

Background

Pacemaker, device leads have been reported to cause tricuspid regurgitation (TR) of variable degrees. It is different between RVA pacing and None-RVA pacing in device-related TR. Few articles indicate this area. Objectives: We sought to evaluate (1) TR degree in patients with right ventricular apical (RVA) pacing vs. none-RVA pacing; (2) the relationship of lead-position between RVA vs. none-RVA pacing associated with TR undergo 3-dimensional echocardiography (3DE).

Methods

Conventional echocardiography performed in 458 patients after pacemaker implantation. In addition, 284 patients with pre-pacemaker implantation echocardiography available were included to evaluate the development of significant TR prospectively.

Results

RVA pacing patients had a higher frequency of significant TR (degree≥2) compared to none-RVA pacing (63% vs. 42%, p-value <0.01). For RVA pacing, the lead was more likely to position at the anterior, posterior and septal compared to none-RVA pacing (51% vs. 33%, p-value <0.01). Importantly, leads were more likely to be positioned in the central portion with none-RVA pacing compared to RVA pacing (30% vs. 13%, p-value <0.01). Among 284 patients with pre-& post-implantation echocardiography, RVA pacing is associated with the development of significant TR compared to none-RVA pacing (59% vs. 41%, P=0.012).

Factors Associated with Significant TR Univariate p-value Multivariate p-value Age 1.035 (1.016–1.055) <0.01 1.025 (1.005–1.047) 0.02 Duration 1.003 (1.001–1.006) 0.02 1.001 (0.998–1.004) 0.62 Male 0678 (0.468–0.980) 0.04 0.657 (0.436–0.991) 0.05 Pre-AF 2.623 (1.740–3.955) <0.01 1.162 (0.588–2.295) 0.67 Post-AF 3.529 (2.329–5.346) <0.01 2.671 (1.566–4.556) <0.01 DDDR 0.428 (0.236–0.777) 0.01 0.724 (0.336–1.563) 0.41 RVA 2.451 (1.673–3.589) <0.01 1.962 (1.266–3.042) <0.01

3D TTE view of the device leads in TVs

Conclusions

The study demonstrates that RVA pacing is more likely to develop significant TR compared to none-RVA pacing. Significantly, this study is the first details to demonstrate that lead impingement is one of the possible mechanisms that could explain the higher frequency of TR in RVA pacing compared to none-RVA pacing by 3DE.

Acknowledgement/Funding

This manuscript is partially supported by the Summit Grant from the University of Hong Kong and Queen Mary Hospital.

Update of Guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias (International Endohernia Society (IEHS))-Part A

Abstract

In 2014, the International Endohernia Society (IEHS) published the first international “Guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias.” Guidelines reflect the currently best available evidence in diagnostics and therapy and give recommendations to help surgeons to standardize their techniques and to improve their results. However, science is a dynamic field which is continuously developing. Therefore, guidelines require regular updates to keep pace with the evolving literature.

Methods

For the development of the original guidelines, all relevant literature published up to year 2012 was analyzed using the ranking of the Oxford Centre for Evidence-Based Medicine. For the present update, all of the previous authors were asked to evaluate the literature published during the recent years from 2012 to 2017 and revise their statements and recommendations given in the initial guidelines accordingly. In two Consensus Conferences (October 2017 Beijing, March 2018 Cologne), the updates were presented, discussed, and confirmed. To avoid redundancy, only new statements or recommendations are included in this paper. Therefore, for full understanding both of the guidelines, the original and the current, must be read. In addition, the new developments in repair of abdominal wall hernias like surgical techniques within the abdominal wall, release operations (transversus muscle release, component separation), Botox application, and robot-assisted repair methods were included.

Results

Due to an increase of the number of patients and further development of surgical techniques, repair of primary and secondary abdominal wall hernias attracts increasing interests of many surgeons. Whereas up to three decades ago hernia-related publications did not exceed 20 per year, currently this number is about 10-fold higher. Recent years are characterized by the advent of new techniques—minimal invasive techniques using robotics and laparoscopy, totally extraperitoneal repairs, novel myofascial release techniques for optimal closure of large defects, and Botox for relaxing the abdominal wall. Furthermore, a concomitant rectus diastasis was recognized as a significant risk factor for recurrence. Despite insufficient evidence with respect to these new techniques, it seemed to us necessary to include them in the update to stimulate surgeons to do research in these fields.

Conclusion

Guidelines are recommendations based on best available evidence intended to help the surgeon to improve the quality of his daily work. However, science is a continuously evolving process, and as such guidelines should be updated about every 3 years. For a comprehensive reference, however, it is suggested to read both the initial guidelines published in 2014 together with the update. Moreover, the presented update includes also techniques which were not known 3 years before.

Therapeutic effect of pregabalin on radiotherapy-induced trismus in nasopharyngeal carcinoma patients

AIMS

To evaluate the effect of pregabalin on radiotherapy-induced trismus in patients with nasopharyngeal carcinoma, a hospital-based, clinical retrospective cohort study was conducted.

MATERIALS AND METHODS

Data were collected on patients diagnosed with radiotherapy-induced trismus from March 2014 and March 2016 in the department of neurology in our hospital. Patients in the treatment group were administrated pregabalin for 8 weeks combined with rehabilitation, while the control group only received rehabilitation. The clinical therapeutic effects were observed and evaluated by mandibular motion, severity of trismus measured by late effects of normal tissues/subjective and objective medical analysis (LENT/SOMA) scales, and quality of life (QOL) assessed using the World Health Organization QOL instrument (WHOQOL-BREF) at baseline, week 4 and week 8 during treatment in these two groups, respectively.

RESULTS

In the treatment group, the number of patients with improvement on maximal vertical dimension (MVD) was significantly more than controls at week 4 and week 8 (P=0.013, P=0.004, respectively). Moreover, at week 4 and week 8, the severity of trismus was both significantly improved on LENT/SOMA grade in treatment group (P=0.047, P=0.032, respectively). And at week 8, the physical health and the whole life domain of the WHOQOL-BREF score were significantly increased (P=0.037, P=0.034, respectively). In the treatment group, 11 patients (36.7%) presented dizziness, and 7 patients (23.3%) presented somnolence.

CONCLUSIONS

Administration of pregabalin, in adjunct to rehabilitation, might provide a better outcome in patients with radiotherapy-induced trismus.

Unveiling the Superconducting Mechanism of Ba_{0.51}K_{0.49}BiO_{3}

The mechanism of high superconducting transition temperatures (T_{c}) in bismuthates remains under debate despite more than 30 years of extensive research. Our angle-resolved photoemission spectroscopy studies on Ba_{0.51}K_{0.49}BiO_{3} reveal an unexpectedly 34% larger bandwidth than in conventional density functional theory calculations. This can be reproduced by calculations that fully account for long-range Coulomb interactions-the first direct demonstration of bandwidth expansion due to the Fock exchange term, a long-accepted and yet uncorroborated fundamental effect in many body physics.Furthermore, we observe an isotropic superconducting gap with 2Δ_{0}/k_{B}T_{c}=3.51±0.05, and strong electron-phonon interactions with a coupling constant λ∼1.3±0.2. These findings solve a long-standing mystery-Ba_{0.51}K_{0.49}BiO_{3} is an extraordinary Bardeen-Cooper-Schrieffer superconductor, where long-range Coulomb interactions expand the bandwidth, enhance electron-phonon coupling, and generate the high T_{c}. Such effects will also be critical for finding new superconductors.

Structure and formation of highly luminescent protein-stabilized gold clusters

Highly luminescent gold clusters simultaneously synthesized and stabilized by protein molecules represent a remarkable category of nanoscale materials with promising applications in bionanotechnology as sensors. Nevertheless, the atomic structure and luminescence mechanism of these gold clusters are still unknown after several years of developments. Herein, we report findings on the structure, luminescence and biomolecular self-assembly of gold clusters stabilized by the large globular protein, bovine serum albumin. We highlight the surprising identification of interlocked gold-thiolate rings as the main gold structural unit. Importantly, such gold clusters are in a rigidified state within the protein scaffold, offering an explanation for their highly luminescent character. Combined free-standing cluster synthesis (without protecting protein scaffold) with rigidifying and un-rigidifying experiments, were designed to further verify the luminescence mechanism and gold atomic structure within the protein. Finally, the biomolecular self-assembly process of the protein-stabilized gold clusters was elucidated by time-dependent X-ray absorption spectroscopy measurements and density functional theory calculations.

Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2)

van der Waals heterostructures (VDWHs) exhibit rich properties and thus has potential for applications, and charge transfer between different layers in a heterostructure often dominates its properties and device performance. It is thus critical to reveal and understand the charge transfer effects in VDWHs, for which electronic structure measurements have proven to be effective. Using angle-resolved photoemission spectroscopy, we studied the electronic structures of (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2), which are naturally occurring VDWHs, and discovered several striking charge transfer effects. When the thickness of the TiSe_{2} layers is halved from m=2 to m=1, the amount of charge transferred increases unexpectedly by more than 250%. This is accompanied by a dramatic drop in the electron-phonon interaction strength far beyond the prediction by first-principles calculations and, consequently, superconductivity only exists in the m=2 compound with strong electron-phonon interaction, albeit with lower carrier density. Furthermore, we found that the amount of charge transferred in both compounds is nearly halved when warmed from below 10 K to room temperature, due to the different thermal expansion coefficients of the constituent layers of these misfit compounds. These unprecedentedly large charge transfer effects might widely exist in VDWHs composed of metal-semiconductor contacts; thus, our results provide important insights for further understanding and applications of VDWHs.

Inhibition of the Effect of High Glucose on the Expression of Smad in Human Peritoneal Mesothelial Cells

Objective

As high glucose (HG) concentration in peritoneal dialysis (PD) solution is thought to contribute to peritoneal fibrosis, and angiotensin II receptor blockers (ARBs) may have a key role in preventing fibrosis as they may inhibit the TGF- ß1–Smad pathway, the aims of this in vitro study were to investigate 1) if HG affects the expression of Smad in human peritoneal mesothelial cells (HPMCs) and 2) if ARB (losartan) can inhibit this effect.

Methods

HPMCs, obtained from non-renal patients undergoing elective abdominal surgery, were stimulated by HG solutions with different concentrations (1.5%, 2.5%, 4.25%) of dextrose and mannitol, and by solutions containing combination with dextrose and losartan. The supernatant was assayed for TGF- ß1 by ELISA and cells were collected for the analysis of Smad family by RT-PCR and Western Blot.

Results

1) HG up-regulated the expression of Smad2 on both gene and protein levels, especially in 2.5% and 4.25% dextrose groups (P&0.05), and also stimulated the expression of Smad4 in 4.25% dextrose group. However, the expression of Smad3 was not affected. 2) High osmolality as such (using mannitol) did not affect the TGF-ß1-Smad signaling pathway. 3) Losartan inhibited the expression of Smad2 on the gene level but not on the protein level. 4) HG up-regulated the level of TGF- ß1 with increasing dextrose concentration, while losartan partially inhibited this effect of HG on releasing of TGF-ß1.

Conclusion

A high glucose solution up-regulated the expression of Smad2 and Smad4, suggesting that the TGF- ß1-Smad pathway could be involved in the fibrosis of the peritoneum during PD. As losartan inhibited the expression of Smad2 on the gene level and reduced the concentration of TGF- ß1 in our study, the results of this in vitro study suggest that the use of angiotensin II receptor blockers might represent a possible way to prevent and treat peritoneal fibrosis in PD patients. However, further studies in vivo are needed to confirm this hypothesis.

Dietary Intake is Positively Associated with Cognitive Function of a Chinese Older Adults Sample

OBJECTIVE

The relationship between cognitive function and dietary intake in older adults was under-studied in China. This study examined this relationship in a Chinese sample while controlling for the effects of sleep quality and socio demographic confounders.

METHODS

The sample consisted of 340 Chinese older adults (age > 60) who were randomly selected from Wuhan city in central China. Cognitive function was assessed by the Mini-mental State Examination [MMSE], sleep quality by the Pittsburgh Sleep Quality Index [PSQI], and dietary intake by frequencies of intake of meat products, fruits, fish/seafood/aquatic products, nuts and mushroom/algae over the past year. First, confirmatory factor analysis (CFA) was conducted to evaluate the measurement properties of cognitive function, dietary intake, and sleep quality. Second, structural equation modeling (SEM) was conducted to examine the relations of cognitive function, dietary intake, and sleep quality.

RESULTS

Dietary intake was found to be positively related to cognitive function. Older age, lower education status, monthly income, and living alone or without a spouse were significantly associated with poorer cognitive function. SES status had an indirect effect on cognitive function via dietary intake.

CONCLUSION

Dietary intake may be critical to maintain normal cognitive function of older adults in China.

Optomechanical properties of GaAs/AlAs micropillar resonators operating in the 18 GHz range

Recent experiments demonstrated that GaAs/AlAs based micropillar cavities are promising systems for quantum optomechanics, allowing the simultaneous three-dimensional confinement of near-infrared photons and acoustic phonons in the 18-100 GHz range. Here, we investigate through numerical simulations the optomechanical properties of this new platform. We evidence how the Poisson's ratio and semiconductor/vacuum boundary conditions lead to very distinct features in the mechanical and optical three-dimensional confinement. We find a strong dependence of the mechanical quality factor and strain distribution on the micropillar radius, in great contrast to what is predicted and observed in the optical domain. The derived optomechanical coupling constants g₀ reach ultra-large values in the 10⁶ rad/s range.

Study on the expression and mechanism of plasma microRNA-21 in patients with ischemic cardiomyopathy

OBJECTIVE

To investigate the expression and mechanism of plasma microRNA-21 in patients with ischemic cardiomyopathy (ICM).

PATIENTS AND METHODS

56 cases of ICM patients were selected in our hospital from February 2010 to March 2016 as the observation group, and 60 cases of healthy patients were selected as control group. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of microRNA-21 in two groups. Then, differences of the total cholesterol (TC), triglycerides (TG), left ventricular ejection fraction (LVEF), high and low density lipoprotein cholesterol (HDL-C, LDL-C), left ventricular end-diastolic volume (LVEDV), N terminal B type brain natriuretic peptide (NT-proBNP) and other clinical indicators of the two groups, were compared. The correlation between the plasma microRNA-21 level and the clinical indices was analyzed, and the value of microRNA-21 in the diagnosis and treatment of ICM was evaluated.

RESULTS

The levels of LDL-C, HDL-C and LVEF in the observation group were lower than those in the control group (p<0.05). Plasma microRNA-21, TG, NT-proBNP and LVEDV were higher than those in the control group; the difference was statistically significant (p<0.05). Logistic regression analysis showed that the plasma microRNA-21 level was positively correlated with NT-proBNP and LVEDV (p<0.05).

CONCLUSIONS

The expression of microRNA-21 in plasma of patients with ICM was significantly increased. And the expression of micro RNA-21 in plasma was positively correlated with NT-proBNP and LVEDV. Through the ventricular remodeling in ICM patients, it can be used as a new target for the diagnosis and treatment of ICM and a new biomarker for risk assessment.

[A randomized controlled clinical trial of acoustic resonance combined with systemic steroid therapy for sudden hearing loss]

Objective:To study the short-term and long-term therapeutic effect of acoustic resonance combined with systemic steroid therapy in treatment of Sudden hearing loss (SHL).Method:Clinical data of 128 patients with SHL were analyzed in the randomized controlled trial. Patients were divided into study group (68 cases) and control group (60 cases). Patients in control group received steroid therapy and conventional drug therapy, while study group received acoustic resonance therapy combined with systemic steroid therapy and conventional drug therapy.Result:The total effective rate of study group and control group was 66.18% and 65.00% respectively at the end of treatment; the total effective rate of study group and control group was 72.06% and 70.00% 4 weeks after treatment; the total efficiency of study group and control group was 73.53% and 68.33% respectively 8 weeks after treatment. The total effective rate of study group was not significantly higher than that of the control group in the three periods (P> 0.05). But the PTA significantly improved in study group 4 weeks and 8 weeks after treatment [(43.87±16.73)dB, (40.96±17.11)dB], while the PTA of control group is (50.89±18.41)dB, (48.93±17.84)dB (P< 0.05), and no serious adverse events were happened during treatments and after treatments.Conclusion:Acoustic resonance combined with systemic steroid therapy can significantly improve the therapeutic effect of SHL with no obvious side effects, which is worth clinical promotion.

[Effects of tetrahydrobiopterin on the angiogenesis in hepatocellular carcinoma]

Objective: To investigate the effect and mechanism of tetrahydrobiopterin (BH4) on the angiogenesis in hepatocellular carcinoma (HCC). Methods: BALB/c-nu mice were subcutaneously injected with HepG-2 cells and randomly divided into control and BH4 groups. The BH4 group and control group received 20 mg/kg BH4 or saline by intraperitoneal injection daily for two weeks, respectively. The level of BH4 was measured by high performance liquid chromatography (HPLC), the level of nitric oxide (NO) was measured by Griess test array, the transcriptional level of K-ras was measured by quantitative RT-PCR, and the protein expressions of guanosine triphosphate cyclohydrolase Ⅰ(GTPCH), endothelial nitric oxide synthase (eNOS), phospho-Akt and Akt were determined by Western blot. Results: BH4 level in the tumor tissues of BH4 group was (0.24±0.02) μg/ml, significantly higher than the (0.17±0.01) μg/ml in the control group (P<0.01). The level of NO in the tumor tissues of BH4 group was (51.44±2.90) mmol/L, significantly higher than the (24.77±0.54) mmol/L in the control group (P<0.01). The tumor volume of BH4 group was (191.05±8.70) mm3, significantly higher than the (103.10±5.03) mm3 in the control group (P<0.01). The expressions of CD34, K-ras, phospho-eNOS, phospho-Akt and GTPCH were significantly up-regulated in the tumor tissues of BH4 group when compared with those of the control group (P<0.01). Conclusions: BH4 recognized as an essential cofactor of eNOS can increase tumor-produced NO by activating the wild-type Ras-PI3K/Akt pathway, thus induces angiogenesis. This might provide a novel and promising way to control the progression of hepatocellular carcinoma through targeting BH4 synthesis pathway and inhibiting angiogenesis.

Highly Anisotropic and Twofold Symmetric Superconducting Gap in Nematically Ordered FeSe_{0.93}S_{0.07}

FeSe exhibits a novel ground state in which superconductivity coexists with a nematic order in the absence of any long-range magnetic order. Here, we report on an angle-resolved photoemission study on the superconducting gap structure in the nematic state of FeSe_{0.93}S_{0.07}, without the complications caused by Fermi surface reconstruction induced by magnetic order. We find that the superconducting gap shows a pronounced twofold anisotropy around the elliptical hole pocket near Z (0, 0, π), with gap minima at the end points of its major axis, while no detectable gap is observed around Γ (0, 0, 0) and the zone corner (π, π, k_{z}). The large anisotropy and nodal gap distribution demonstrate the substantial effects of the nematicity on the superconductivity and thus put strong constraints on current theories.

Erratum: Structural and Electronic Properties of Germanene on MoS_{2} [Phys. Rev. Lett. 116, 256804 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.116.256804.