Room-temperature quantum emission from interface excitons in mixed-dimensional heterostructures

The development of van der Waals heterostructures has introduced unconventional phenomena that emerge at atomically precise interfaces. For example, interlayer excitons in two-dimensional transition metal dichalcogenides show intriguing optical properties at low temperatures. Here we report on room-temperature observation of interface excitons in mixed-dimensional heterostructures consisting of two-dimensional tungsten diselenide and one-dimensional carbon nanotubes. Bright emission peaks originating from the interface are identified, spanning a broad energy range within the telecommunication wavelengths. The effect of band alignment is investigated by systematically varying the nanotube bandgap, and we assign the new peaks to interface excitons as they only appear in type-II heterostructures. Room-temperature localization of low-energy interface excitons is indicated by extended lifetimes as well as small excitation saturation powers, and photon correlation measurements confirm antibunching. With mixed-dimensional van der Waals heterostructures where band alignment can be engineered, new opportunities for quantum photonics are envisioned.

Characteristic hysteroscopy appearance considerations for detecting uterine endometrial malignancies

AIM

The effectiveness of hysteroscopy in diagnosing endometrial lesions has been demonstrated, showing high diagnostic accuracy for malignant endometrial lesions. Although the characteristic appearances of atypical and malignant endometria have been reported, they are not definitive and sometimes complicated. This study aimed to identify a small number of characteristic features to detect endometrial abnormalities using a simple judgment system and analyze the diagnostic characteristics and their accuracy in endometrial malignancy diagnosis.

METHODS

We performed a retrospective analysis of hysteroscopy video data of 250 patients, of which we selected for analysis based on pathology examination 152 cases with benign changes, 16 with atypical endometrium, and 18 with carcinoma in situ or endometrial cancer. Endometrial characteristics assessed included protrusion, desquamation, extended vessel, atypical vessel, and white/yellow lesion.

RESULTS

Multivariable analysis revealed that desquamation (p = 0.001, odds ratio [OR] 5.28), atypical vessels (p < 0.001, OR 8.50), and white/yellow lesions (p = 0.011, OR 1.37) were significant predictors for endometrial malignancy. From their contribution status, scoring points of 4, 6, and 1 were settled according to the odds ratio proportions. When scores ≥5 (at least both desquamation and white/yellow lesions or only atypical vessels) were used to define endometrial malignancy, sensitivity and specificity were 100% and 92%, respectively. When detecting cancer, atypical, and benign cases, sensitivity and specificity were 88% and 90%, respectively.

CONCLUSION

Our characteristics hysteroscopic findings showed a higher predictive ability in detecting endometrial malignancies. However, further examination with more cases would be needed to accurately diagnose endometrial malignancy by hysteroscopy.

Automated system for diagnosing endometrial cancer by adopting deep-learning technology in hysteroscopy

Endometrial cancer is a ubiquitous gynecological disease with increasing global incidence. Therefore, despite the lack of an established screening technique to date, early diagnosis of endometrial cancer assumes critical importance. This paper presents an artificial-intelligence-based system to detect the regions affected by endometrial cancer automatically from hysteroscopic images. In this study, 177 patients (60 with normal endometrium, 21 with uterine myoma, 60 with endometrial polyp, 15 with atypical endometrial hyperplasia, and 21 with endometrial cancer) with a history of hysteroscopy were recruited. Machine-learning techniques based on three popular deep neural network models were employed, and a continuity-analysis method was developed to enhance the accuracy of cancer diagnosis. Finally, we investigated if the accuracy could be improved by combining all the trained models. The results reveal that the diagnosis accuracy was approximately 80% (78.91–80.93%) when using the standard method, and it increased to 89% (83.94–89.13%) and exceeded 90% (i.e., 90.29%) when employing the proposed continuity analysis and combining the three neural networks, respectively. The corresponding sensitivity and specificity equaled 91.66% and 89.36%, respectively. These findings demonstrate the proposed method to be sufficient to facilitate timely diagnosis of endometrial cancer in the near future.

Utility of a minimal skin incision technique for abdominal hysterectomy at a regional core hospital: a retrospective study

BACKGROUND

We present a minimal skin wound abdominal hysterectomy for patients with leiomyomas and describe the characteristics of this technique. The skin wound was made as small as possible, with a maximum length of 6 cm.

METHODS

In addition to introducing minimal skin wound abdominal hysterectomy, we retrospectively analyzed the medical records of 82 patients treated with minimal skin wound abdominal hysterectomy exclusively by two experts at Maruyama Memorial General Hospital between January 2013 and December 2016. Relationships between the leiomyoma characteristics and the difficulty of this operation, as estimated by operation time and blood loss, were statistically investigated.

RESULTS

First, we introduce a case in which we performed minimal skin wound abdominal hysterectomy on a 46-year-old Japanese patient with multiple leiomyomas (maximum 8 cm in diameter). Then, we assessed the impacts of the leiomyoma characteristics on the difficulty of this operation. On multivariate analysis, the number of leiomyomas significantly affected operation difficulty. Other characteristics of the target leiomyoma showed no effect. Additionally, higher body mass index also made the operation more difficult.

CONCLUSIONS

Although multiple leiomyomas can make this procedure difficult, minimal skin wound abdominal hysterectomy is safe and effective for use in many cases.

Effect of empagliflozin versus placebo on body composition in patients with acute myocardial infarction and type 2 diabetes mellitus: subgroup analysis of the EMBODY trial

Background

Prevention of heart failure is one of the most important challenges after acute myocardial infarction (AMI). The development of heart failure is closely associated with fluid balance which can be evaluated by the measurement of body composition such as total body water (TBW), extracellular water (ECW), and intracellular water (ICW). This subgroup analysis of the EMBODY trial was designed to determine whether the Sodium–glucose cotransporter 2 (SGLT2) inhibitor affect fluid balance and improve heart failure in patients after AMI.

Methods

The EMBODY trial was a prospective, multicenter, randomized, double-blind, placebo-controlled trial in patients with AMI and type 2 diabetes in Japan. A total of 105 patients were randomized (1:1) to receive once-daily 10 mg empagliflozin, an SGLT2 inhibitor or placebo 2 weeks after the onset of AMI. In this subanalysis, we investigated the time-course of body composition measured by a bioelectrical impedance analyzer “InBody®”. The primary endpoints were changes in every particular parameter of body composition at week 0, 4, 12, and 24. Secondary endpoints were changes in blood pressure (BP), body weight and N-terminal pro b-type natriuretic peptide (NT-proBNP).

Results

Overall, 55 patients were included in the full analysis set (67.2±10.0 years, male 78.2%, and n=30 in empagliflozin group and 25 in placebo group). Baseline characteristics were not significantly different between the two groups. The change between at baseline and 24 weeks in TBW was −0.44 L (P=0.19) in the empagliflozin group and +1.14 L (P=0.0002) in the placebo group, adjusted difference −1.58 L, 95% confidence interval (CI) −2.46 to −0.70 L (P=0.0006). The empagliflozin group showed significant decreases in the body weight, ECW, ICW and systolic BP compared with the placebo group (−2.2 kg vs, +0.01 kg, P=0.004, −0.21 L vs, +0.40 L, P=0.001, −0.23 L vs, +0.74 L, P=0.0007, and −11.0 mmHg vs, +5.0 mmHg, P&lt;0.0001, respectively). On the other hand, NT-Pro BNP levels significantly decreased in the empagliflozin group and placebo group (1028.7 pg/mL to 370.3 pg/ml, p=0.0001 and 1270.6 pg/mL to 673.7 pg/ml, p=0.006, respectively). In the multiple regression analysis of the change in TBW and ICW for the empagliflozin group, systolic BP was identified as a significant factor (P=0.001, and 0.003, respectively). In stratified analysis of BMI 25 kg/m2 or more, the empagliflozin group showed significant decreases in body weight, TBW, ECW and ICW compared with the placebo group, but not below BMI 25 kg/m2 group.

Conclusion

Empagliflozin reduced not only body weight, but also TBW, ECW and ICW. Interestingly, this tendency was remarkable at BMI 25 or more. This study suggested that early SGLT2 inhibitor administration in obesity patients with AMI and DM might be effective to reduce body weight and TBW.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Boehringer Ingelheim

Changes of QT interval in the acute phase after pulmonary vein isolation for paroxysmal atrial fibrillation

Introduction

Pulmonary vein isolation (PVI) affects ganglionated plexi (GP) around the atrium, leading to a modification of the intrinsic cardiac autonomic system (ANS). In animal models, GP ablation has a potential risk of QT prolongation and ventricular arrhythmias. However, the impact of PVI on QT intervals in humans remains unclear.

Purpose

This study aims to evaluate the Impact of PVI on QT interval in patients with paroxysmal atrial fibrillation.

Methods

We analyzed consecutive 117 PAF patients for their first PVI procedures. 12-lead ECG was evaluated at baseline, 4 hr, day 1, 1 month, and 3 months after ablation. Only patients with sinus rhythm on 12-lead ECG at each evaluation point without antiarrhythmic drugs were included.

Results

Heart rate significantly increased at 4 hr, day 1, and 1 month. Raw QT interval prolonged at 4 hr (417.1±41.6 ms, P&lt;0.001) but shortened at day 1 (376.4±34.1 ms, P&lt;0.001), 1 month (382.2±31.5 ms, P&lt;0.001), and 3 months (385.1±32.8 ms, P&lt;0.001) compared to baseline (391.6±31.4 ms). Bazett- and Fridericia- corrected QTc intervals significantly prolonged at 4hr (Bazett: 430.8±27.9 ms, P&lt;0.001; Fridericia: 425.8±27.4 ms, P&lt;0.001), day1 (Bazett: 434.8±22.3 ms, P&lt;0.001; Fridericia: 414.1±23.7 ms, P&lt;0.001), 1M (Bazett: 434.8±22.3 ms, P&lt;0.001; Fridericia: 408.2±21.0 ms, P&lt;0.05), and 3M (Bazett: 420.1±21.8 ms, P&lt;0.001; Fridericia: 407.8±21.1 ms, P&lt;0.05) compared to baseline (Bazett: 404.9±25.2 ms; Fridericia: 400.0±22.6 ms). On the other hand, Framingham- and Hodges- corrected QTc interval significantly prolonged only at 4hr (Framingham: 424.1±26.6 ms, P&lt;0.001; Hodges: 426.8±28.4 ms, P&lt;0.001) and at day1 (Framingham: 412.3±29.3 ms, P&lt;0.01; Hodges: 410.6±40.2 ms, P&lt;0.05) compared to baseline (Framingham: 399.2±22.7 ms; Hodges: 400.7±22.8 ms). At 4 hr after ablation, raw QT and QTc of all formulas significantly prolonged than baseline. Raw QT and QTc prolongation at 4hr after ablation were more frequently observed in female patients. Multiple regression analysis revealed that female patient is a significant predictor of raw QT and QTc interval prolongation of all formulas 4hr after PVI.

Conclusions

Raw QT and QTc prolonged after PVI, especially in the acute phase. Female patient is a risk factor for QT prolongation in the acute phase after PVI.

Funding Acknowledgement

Type of funding source: None

P2850Time to isolation guided hot balloon ablation for pulmonary vein isolation

Background

One disadvantage of hot balloon ablation (HBA) system is that real time monitoring of pulmonary vein (PV) potential is technically impossible. Therefore, the optimal radiofrequency-generated thermal energy application duration and application number are not completely established.

Purpose

The aim of this study is to evaluate the utility of 2Fr 4-electrode unidirectional catheter inserted into PV along with HB for real time monitoring of PV potential and investigate the time to isolation (TTI) guided optimal application strategy for HB based PV isolation in the acute phase.

Methods

We evaluated 23 consecutive patients who performed PV isolation using HBA system. Real time monitoring of PV potential was performed by 2Fr 4-electrode unidirectional catheter inserted into PV along with HB (Figure1A). After HBA applications, PV isolation was validated by high-resolution mapping with the 20-pole steerable mapping (PENTARAY) catheter as a standard. PV potentials during HBA application were categorized into five patterns. PV potentials disappeared during HBA applications and not emerged again (acute isolation), disappeared but verified by PENTARAY catheter (pseudo isolation), once disappeared but emerged again during the same application (acute reconnection), visible but not disappeared (ineffective application) and Invisible (Figure1B).

TTI, difference between TTI and time to reach target temperature (TTRT), balloon temperature at isolation and ablation time after isolation were examined for each applications.

Results

Out of 92 PVs, 69/92 (75.0%) PVs were isolated using HBA and 23/92 (25.0%) PVs required touch up ablation. In total, 120 applications were performed. Real time monitoring of the PV activity was obtained in 114 of 120 applications (95.0%). The distribution of PV potential patterns were 64/120 (53.3%), 2/120 (1.7%), 27/120 (22.5%), 23/120 (19.2%), for acute isolation, pseudo isolation, acute reconnection, ineffective application, respectively.

TTI and difference between TTI and TTRT were significantly shorter in the acute isolation group. Balloon temperature at isolation was significantly lower, TTRT and ablation time after isolation was significantly longer in the acute isolation group. Among them, TTI and difference between TTI and TTRT were highly predictive by receiver operation characteristics curve analysis. TTI <36.5s predicted successful application with sensitivity 83.9% and specificity 79.3%. Difference between TTI and TTRT <6.5s predicted with sensitivity 82.3% and specificity 89.7%.

Figure 1

Conclusions

In HBA system, real time monitoring of PV potentials can be obtained using 2Fr 4-electrode unidirectional catheter and accuracy to confirm an ostial PV isolation is relatively high.

TTI <36.5s and difference between TTI and TTRT <6.5s could be a suitable target for effective application.

Three-dimensional SAFT imaging for anisotropic materials using photoacoustic microscopy

A pulsed laser illuminates a target zone that causes rapid thermoelastic expansion, generating broadband high-frequency ultrasonic wave (photoacoustic wave, PA wave). We developed a PA microscopy (PAM) with a confocal area of laser and ultrasonic wave for applications in nondestructive testing (NDT). The synthetic aperture focusing technique (SAFT) is applied in the PAM for the three-dimensional (3D) imaging of interior flaws. Here, we report proof-of-concept experiments for the NDT of a subsurface flaw in a thin laminar material. Graphical abstract (a) shows a specimen of carbon-fiber-reinforced plastic (CFRP) with an artificial delamination. Here, it should be noted that the group velocity varies directionally due to the strong anisotropy of the CFRP specimen (see Graphical abstract (b)). By considering the group velocity distribution in the SAFT, the shape and location of the subsurface delamination were accurately estimated as shown in Graphical abstract (c). Coating the surface of the CFRP specimen with a light-absorbent material improved the amplitude of the PA wave. This finding showed that the signal-to-noise ratio of the waves scattered from the flaws can be improved.

Prediction of the operative time for hysteroscopic myomectomy for leiomyomas penetrating the intramural cavity using leiomyoma weight and clinical characteristics of patients

PURPOSE

To preoperatively predict the operative time (OT) for hysteroscopic myomectomy for G1 or G2 leiomyoma based on leiomyoma weight.

METHODS

The data from 544 patients who underwent one-step hysteroscopic myomectomy were analyzed retrospectively. A total of 340 patients with leiomyoma penetrating the intramural cavity were identified as suitable candidates for calculation of the OT based on leiomyoma weight; we considered leiomyoma weight to be the most objective parameter for evaluating leiomyoma tissues. Additionally, 460 patients with a single leiomyoma were analyzed to estimate the weight of the resected leiomyoma based on its diameter.

RESULTS

Considering total leiomyoma weight (TLW) and two additional coefficients (1.5: G2 leiomyoma, 0.75: vaginal parity of the patient), we demonstrated that our formula correlated well with OT (R 2 = 0.72). TLW also correlated well with the cube of the average diameter (AD) of leiomyomas (R 2 = 0.89). Predicting TLW significantly improved the application of specific coefficients depending on its value (1.0: AD 0.1-2.0 cm, 0.8: AD 2.1-3.0 cm, 0.7: AD 3.1-5.7 cm).

CONCLUSION

The OT for hysteroscopic myomectomy of intracavital leiomyoma can be predicted prior to surgery using simple clinical information of the target leiomyoma and the patient.

Anaplastic carcinoma in ovarian seromucinous cystic tumor of borderline malignancy

Background

The mortality rate of ovarian cancer is the highest among all gynecological malignancies in Japan. Ovarian tumors are classified as benign, borderline malignant, or malignant. Anticipating the histological subtype with imaging only is often difficult because of several histological subtypes of epithelial ovarian tumors (such as serous, mucinous, endometrioid, clear cell, and Brenner tumors). In addition, the majority of mucinous tumors in the ovary are metastatic. Furthermore, mucinous tumors belong to one of the two different subclasses (i.e., intestinal and seromucinous types). Ovarian seromucinous cystic tumors of borderline malignancy are infrequent and only rarely coexist with other malignant tumors.

Case presentation

We have reported a 53-year-old Japanese woman with anaplastic carcinoma in an ovarian seromucinous cystic tumor of borderline malignancy. Her MRI and CT analysis revealed an ovarian tumor with a mural nodule, ascites, and peritoneal dissemination. Enhanced MRI revealed that the mural nodule was enhanced. Enhanced CT analysis revealed that the lymph nodes were not swollen. Intriguingly, the mural nodule crossed the cyst wall into the cavity and onto the surface. Her laboratory data revealed high serum CA 125 level. Cumulatively, these results suggested ovarian malignancy. The patient underwent hysterectomy with bilateral salpingo-oophorectomy, omentectomy, and resection of the disseminated lesions. Lymph node biopsy was omitted because of the suggestion of enhanced CT image findings and palpation during surgery. Her postoperative specimen examination determined FIGO at least stage IIIB, and accordingly, adjuvant chemotherapy was prescribed. After 3 years of the operation, the patient is presently alive without clinical tumor recurrences.

Conclusion

Imaging studies with pathognomonic findings contributed to ovarian cancer diagnosis in this case. To the best of our knowledge, this is the first study in English literature to report detailed classification of mucinous borderline malignancy, seromucinous cystic, and anaplastic carcinoma in an ovarian seromucinous cystic tumor of borderline malignancy.

Low Molecular Weight Trypsin-Plasmin Inhibitors Isolated from Papain Treated Urinary Trypsin Inhibitor

Papain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.

Studies on Blood Coagulation and Fibrinolysis in Patients Bitten by Bothrops jararaca (jararaca)

The blood coagulation and the fibrinolytic systems of nine patients envenomed by Bothrops jararaca in São Paulo (Brazil) were studied. Five of the accidents were caused by young snakes (<50 cm). On admission, four patients had non-clotting and three partially-clotting blood. Fibrinogen levels were decreased due to the thrombin-like activity of the venom as expected. Consequent secondary activation of the fibrinolytic system was evident from the low levels of alpha-2-antiplasmin and the high titres of fibrin(ogen) degradation products. High titres of cross-linked fibrin fragment D (D-dimer) in seven patients together with decreased platelet counts and/or factor V, and/or factor VIII in some, suggests intrinsic thrombin formation as these factors are not consumed in the defibrinogenation induced by venom thrombin-like fractions such as Ancrod and Batroxobin. However, normal or increased levels of antithrombin III in all and normal levels of factor II in eight patients do not support this interpretation. The existence of variable concentrations of other proteins in the venom of B. jararaca such as botrocetin and thrombocytin isolated from B. jararaca and B. atrox or crotalocytin from Crotaliis horridus venom should be considered. Such proteins are known to activate factors V, VIII, XIII, and platelets without affecting prothrombin (factor II) and antithrombin III. Slower recovery of the haemostatic disturbances after antivenom administration to patients bitten by young snakes suggests a more severe coagulopathy in such accidents. This is supported by clinical observations.

Utility of a minimal skin incision laparotomy technique for removing uterine leiomyomas at a regional core hospital: a retrospective study

BACKGROUND

We present a minimal skin wound abdominal myomectomy performed in our hospital and attempt to identify the optimal range of this technique by considering the characteristics of target leiomyomas. In this procedure, we attempted to make the skin wound as small as possible, with a maximum length of approximately 5 cm.

METHODS

In addition to introducing the minimal skin wound abdominal myomectomy, we retrospectively collected and analyzed the medical records of 76 patients treated with minimal skin wound abdominal myomectomy exclusively by the same physician at Maruyama Memorial General Hospital between January 2007 and December 2016. We statistically investigated relationships between ten factors, including body mass index; patient's age; patient's parity; administration of gonadotropin-releasing hormone analogue; presence of anemia; the uterine leiomyomas' number, size, weight, and location; operation time; and blood loss.

RESULTS

First, we introduce a case in which we performed minimal skin wound abdominal myomectomy for a 36-year-old Japanese patient with a large leiomyoma (10 cm in diameter). Then, we assessed the impacts of patient characteristics and leiomyoma characteristics on operation time and blood loss for this surgical method. In a multivariate analysis, only the number of resected leiomyomas significantly affected massive bleeding. Other factors showed no difference on operation time and the amount of blood loss.

CONCLUSIONS

Minimal skin wound abdominal myomectomy is safe and effective for use in many patients, because only the number of leiomyomas affects the amount of blood loss. No other factor affected operation time. We suggest the possibility that the expanded use of minimal skin wound abdominal myomectomy may reduce the number of patients waiting for long periods to undergo laparoscopic surgery and may optimize the use of medical resources in rural areas.

Characterisation of a sucrose-independent in vitro biofilm model of supragingival plaque

OBJECTIVES

Sugar consumption has been decreasing in Japan, suggesting higher rates of sucrose-independent supragingival plaque formation. For developing an in vitro biofilm model of sucrose-independent supragingival plaque, this study aimed to investigate the compositions and functions on contributing to cariogenicity in comparison with sucrose-dependent biofilm.

MATERIALS AND METHODS

An in vitro multispecies biofilm containing Actinomyces naeslundii, Streptococcus gordonii, S. mutans, Veillonella parvula and Fusobacterium nucleatum was formed on 24-well plates in the absence or presence of 1% sucrose. Compositions were assessed by plate culture, scanning electron microscopy and confocal laser scanning microscopy after fluorescent in situ hybridisation or labelling of extracellular polymeric substances (EPS). Functions were assessed by acidogenicity, adherence strength and sensitivities to anticaries agents.

RESULTS

Although both biofilms exhibited a Streptococcus predominant bacterial composition, there were differences in bacterial and EPS compositions; in particular, little glucan EPS was observed in sucrose-independent biofilm. Compared with sucrose-dependent biofilm, acidogenicity, adherence strength and antimicrobial resistance of sucrose-independent biofilm were only slightly lower. However, dextranase degradation was substantially lower in sucrose-independent biofilm.

CONCLUSION

Our findings suggest that sucrose-independent biofilm may have cariogenicity as with sucrose-dependent biofilm. These in vitro models can help further elucidate plaque-induced caries aetiology and develop new anticaries agents.