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Traumatic neuromas (TNs) mimic recurrent tumors in US after total thyroidectomy (TT) and lateral neck dissection (LND) for thyroid cancer. We aimed to evaluate whether CT could complement US in the differential diagnosis of TNs from recurrent thyroid cancer in the dissected neck. We retrospectively included a total of 97 consecutive US-detected lesions (28 TNs and 69 recurrent tumors) in patients with a previous history of TT and LND for thyroid cancer. The lesions were classified as benign, indeterminate, or suspicious according to the presence of benign or suspicious features on US and CT. Imaging features and categories on US and CT were compared between TNs and recurrent tumors. The diagnostic performances of US and CT for differentiating between TNs and recurrent tumors were calculated. On US, most TNs and recurrent tumors showed internal hyperechogenicity without hilar echogenicity or hilar vascularity and were categorized as suspicious lesions (23/28, 82.1% vs. 53/69, 76.8%). On CT, all TNs lacked strong enhancement without hilar fat or hilar vessel enhancement and were categorized as indeterminate lesions (28/28, 100%). In contrast, most recurrent tumors showed strong enhancement and were categorized as suspicious lesions (63/69, 91.3%). The addition of CT to US corrected 23 false-positive diagnoses in 28 TNs and 10 false-negative diagnoses in 69 recurrent tumors. CT complements US for the correct differentiation of TNs from recurrent tumors in postoperative thyroid cancer patients. The addition of CT to US may prevent unnecessary painful biopsy or surgery. • In the dissected neck, traumatic neuromas could mimic US suspicious LNs owing to its internal hyperechogenicity. • CT effectively differentiated traumatic neuromas from recurrent thyroid cancers by demonstrating significantly different enhancement patterns. • CT could complement US and may prevent unnecessary painful biopsy or surgery for US-detected lesions after thyroidectomy and neck dissection.

Background: Congenital diaphragmatic hernia (CDH) is a rare disease often requiring mechanical ventilation after birth. In severe cases, extracorporeal membrane oxygenation (ECMO) may be needed. This study analyzed the outcomes of patients with CDH treated with ECMO and investigated factors related to in-hospital mortality. Methods: Among 254 newborns diagnosed with CDH between 2008 and 2020, 51 patients needed ECMO support. At Asan Medical Center, a multidisciplinary team approach has been applied for managing newborns with CDH since 2018. Outcomes were compared between hospital survivors and nonsurvivors. Results: ECMO was established at a median of 17 hours after birth. The mean birth weight was 3.1±0.5 kg. Twenty-three patients (23/51, 45.1%) were weaned from ECMO, and 16 patients (16/51, 31.4%) survived to discharge. The ECMO mode was veno-venous in 24 patients (47.1%) and veno-arterial in 27 patients (52.9%). Most cannulations (50/51, 98%) were accomplished through a transverse cervical incision. No significant between-group differences in baseline characteristics and prenatal indices were observed. The oxygenation index (1 hour before: 90.0 vs. 51.0, p=0.005) and blood lactate level (peak: 7.9 vs. 5.2 mmol/L, p=0.023) before ECMO were higher in nonsurvivors. Major bleeding during ECMO more frequently occurred in nonsurvivors (57.1% vs. 12.5%, p=0.007). In the multivariate analysis, the oxygenation index measured at 1 hour before ECMO initiation was identified as a significant risk factor for in-hospital mortality (odds ratio, 1.02; 95% confidence interval, 1.01–1.04; p=0.05). Conclusion: The survival of neonates after ECMO for CDH is suboptimal. Timely application of ECMO is crucial for better survival outcomes.

After attaining a qualified medical capacity in organ transplantation, Korea has been struggling to increase the number of deceased organ transplants to reach self-sufficiency. As one of these efforts, Korea revised the organ transplantation law in 2010 by adding three articles the mandatory reporting based on the recommendation of the 3rd Global Consultation on Organ Transplantation of Madrid in 2010. Along with the new constitution, considerable efforts have been initiated to upgrade the deceased organ transplantation system while maintaining the virtues of fairness, justice, and transparency. The Korean Society of Transplantation played a critical role in revising the law as well as in establishing organizations such as the Korean Organ Donation Agency (KODA; 2009), the Vitallink (2009), and the Korean Organ Transplantation Registry (KOTRY; 2010). By the activities of these professional organizations, Korea could implement fundamental programs such as mandatory reporting and could develop various education programs for organ donation for students and the general population. As a result, the number of deceased donors increased from 1.08 p.m.p. (2000) to 9.23 p.m.p.(2020). Further efforts are needed to increase the number of organ donor cardholders and family consent rates by well-designed, target-specific education programs to overcome traditional negative cultural barriers toward organ donation. The community atmosphere of honoring and thanking donors and their families should be nurtured by national and regional activities of life-sharing weeks linked with organ donor memorial parks.

Our study investigated the feasibility and clinical relevance of brain age prediction using axial T2-weighted images (T2-WIs) with a deep convolutional neural network (CNN) algorithm. The CNN model was trained by 1,530 scans in our institution. The performance was evaluated by the mean absolute error (MAE) between the predicted brain age and the chronological age based on an internal test set (n=270) and an external test set (n=560). The ensemble CNN model showed an MAE of 4.22 years in the internal test set and 9.96 years in the external test set. Participants with grade 2-3 white matter hyperintensity (WMH) showed a higher corrected predicted age difference (PAD) than grade 0 WMH (posthoc p

Surface plasmon resonance (SPR) owing to its extreme sensitivity to the refractive index of surrounding medium has been widely applied to chemical and biological sensing. However, it is difficult to realize SPR sensing simultaneously with large sensitivity and figure of merit (FOM) in a conventional prism coupling structure. In this paper, we numerically study the SPRs in a polymer-protected sodium thin film and sinusoidal nanograting based on a prism Kretschmann configuration using finite element method (FEM). In the near-infrared wavelengths, both angular and wavelength interrogation are investigated and high sensitivity (14.9 μm/RIU and 750 deg/RIU for the thin film and nanograting, respectively) and FOM (480.6 /RIU and 255.6 /RIU for the thin film and nanograting, respectively) can be achieved simultaneously. It should be noticed that the large FOM mainly originates from the narrow resonant linewidth. Additionally, our nanograting structure can support a self-reference sensing scheme, which is beneficial to realize accurate sensing. Our FEM simulations are in good agreement with the calculation by the transfer matrix method (TMM) and rigorous coupled wave analysis (RCWA). Our proposed sodium-based SPR structures do not require complex plasmonic nanostructures and are compatible with a thermo-assisted spin-coating process, which shows great potential in realizing high-performance optical sensing beyond noble metals and expands the application scope of sodium-based plasmonic devices.

Strategies for stem cell-based cardiac regeneration and repair are key issues for the ischemic heart disease (IHD) patients with chronic complications related to ischemic necrosis. Cardiac stem cells (CSCs) have demonstrated high therapeutic efficacy for IHD treatment owing to their specific cardiac-lineage commitment. The therapeutic potential of CSCs could be further enhanced by designing a cellular spheroid formulation. The spheroid culture condition of CSCs was optimized to ensure regulated size and minimal core necrosis in the spheroids. The CSC spheroids revealed mRNA profiles of the factors related to cardiac regeneration, angiogenesis, anti-inflammatory, and cardiomyocyte differentiation with a higher expression level than the CSCs. Intramyocardially delivered CSC spheroids in the rat IHD model resulted in a significant increase in retention rate by 1.82-fold (day 3) and 1.98-fold (day 14) compared to CSCs. Endothelial cell differentiation and neovascularization of the engrafted CSC spheroids were noted in the infarcted myocardium. CSC spheroids significantly promoted cardiac regeneration: i.e., decreased infarction and fibrotic area (11.22% and 4.18%) and increased left ventricle thickness (0.62 mm) compared to the untreated group. Cardiac performance was also improved by 2.04-fold and 1.44-fold increase in the ejection fraction and fractional shortening, respectively. Intramyocardial administration of CSC spheroids might serve as an advanced therapeutic modality with enhanced cell engraftment and regenerative abilities for cardiac repair after myocardial infarction.

Dance is a popular activity throughout the world. There are many styles of dance, each having distinct physical demands and injury patterns. Healthcare providers should have some familiarity with the typical injuries seen in the dancer’s foot and ankle. Along with strong physical exam skills, an understanding of the best imaging options is paramount. High-resolution ultrasound can often be used as reliably as MRI for many of these diagnoses. The present article aims to brief the regional anatomy, address the typical presentation, and review exam findings and management options for the care of dancers’ injuries in the foot and ankle.

OBJECTIVE To develop a radiomics risk score based on dynamic contrast-enhanced (DCE) MRI for prognosis prediction in patients with glioblastoma. MATERIALS AND METHODS One hundred and fifty patients (92 male [61.3%]; mean age ± standard deviation, 60.5 ± 13.5 years) with glioblastoma who underwent preoperative MRI were enrolled in the study. Six hundred and forty-two radiomic features were extracted from volume transfer constant (Ktrans), fractional volume of vascular plasma space (Vp), and fractional volume of extravascular extracellular space (Ve) maps of DCE MRI, wherein the regions of interest were based on both T1-weighted contrast-enhancing areas and non-enhancing T2 hyperintense areas. Using feature selection algorithms, salient radiomic features were selected from the 642 features. Next, a radiomics risk score was developed using a weighted combination of the selected features in the discovery set (n = 105); the risk score was validated in the validation set (n = 45) by investigating the difference in prognosis between the "radiomics risk score" groups. Finally, multivariable Cox regression analysis for progression-free survival was performed using the radiomics risk score and clinical variables as covariates. RESULTS 16 radiomic features obtained from non-enhancing T2 hyperintense areas were selected among the 642 features identified. The radiomics risk score was used to stratify high- and low-risk groups in both the discovery and validation sets (both p < 0.001 by the log-rank test). The radiomics risk score and presence of isocitrate dehydrogenase (IDH) mutation showed independent associations with progression-free survival in opposite directions (hazard ratio, 3.56; p = 0.004 and hazard ratio, 0.34; p = 0.022, respectively). CONCLUSION We developed and validated the "radiomics risk score" from the features of DCE MRI based on non-enhancing T2 hyperintense areas for risk stratification of patients with glioblastoma. It was associated with progression-free survival independently of IDH mutation status.

Background Only a few studies have established the epidemiology of prolactinoma and Cushing's disease in Korea. Furthermore, the incidence of these disease are increasing than before associated with the development of technologies. This study was designed to evaluate the epidemiology of prolactinoma and Cushing's disease and their survival analysis according to treatment. Methods The nationwide, population-based study evaluated incidence and prevalence of prolactinoma and Cushing's disease using de-identified claims data in The Korean Health Insurance Review and Assessment Service database between 2013 and 2017. The survival analysis investigated regarding treatment over a period of 6 years. A log-rank test and Cox proportional hazard regression analysis were used. Results The 6,056 patients with newly diagnosed prolactinoma and 584 patients with Cushing's disease were recorded between 2013 and 2017. The annual incidence of prolactinoma was 23.5 cases per million, and its prevalence was 82.5 cases per million, and 2.3 cases per million/year and 9.8 cases per million for Cushing's disease. The survival benefit was insignificant in prolactinoma according to treatment, but treatment of Cushing's disease ameliorated the survival rate significantly. Conclusion Overall, the incidence of prolactinoma and Cushing's disease was similar with those found previously, but the prevalence of two diseases were inconsistent when compared with the early studies. The present study also proposed necessity of treatment in Cushing's disease for improving the survival rate.

Background Considering the limited accessibility of amyloid position emission tomography (PET) in patients with dementia, we proposed a deep learning (DL)-based amyloid PET positivity classification model from PET images with 2-deoxy-2-[fluorine-18]fluoro-D-glucose (2-[18F]FDG). Methods We used 2-[18F]FDG PET datasets from the Alzheimer's Disease Neuroimaging Initiative and Korean Brain Aging Study for the Early diagnosis and prediction of Alzheimer’s disease for model development. Moreover, we used an independent dataset from another hospital. A 2.5-D deep learning architecture was constructed using 291 submodules and three axes images as the input. We conducted the voxel-wise analysis to assess the regions with substantial differences in glucose metabolism between the amyloid PET-positive and PET-negative participants. This facilitated an understanding of the deep model classification. In addition, we compared these regions with the classification probability from the submodules. Results There were 686 out of 1433 (47.9%) and 50 out of 100 (50%) amyloid PET-positive participants in the training and internal validation datasets and the external validation datasets, respectively. With 50 times iterations of model training and validation, the model achieved an AUC of 0.811 (95% confidence interval (CI) of 0.803–0.819) and 0.798 (95% CI, 0.789–0.807) on the internal and external validation datasets, respectively. The area under the curve (AUC) was 0.860 when tested with the model with the highest value (0.864) on the external validation dataset. Moreover, it had 75.0% accuracy, 76.0% sensitivity, 74.0% specificity, and 75.0% F1-score. We found an overlap between the regions within the default mode network, thus generating high classification values. Conclusion The proposed model based on the 2-[18F]FDG PET imaging data and a DL framework might successfully classify amyloid PET positivity in clinical practice, without performing amyloid PET, which have limited accessibility.

This study aimed to evaluate whether arterial input functions (AIFs) obtained from dynamic susceptibility contrast (DSC)–MRI (AIFDSC) improve the reliability and diagnostic accuracy of dynamic contrast–enhanced (DCE)–derived pharmacokinetic (PK) parameters for differentiating glioblastoma from primary CNS lymphoma (PCNSL) compared with AIFs derived from DCE-MRI (AIFDCE). This retrospective study included 172 patients with glioblastoma (n = 147) and PCNSL (n = 25). All patients had undergone preoperative DSC- and DCE-MRI. The volume transfer constant (Ktrans), volume of the vascular plasma space (vp), and volume of the extravascular extracellular space (ve) were acquired using AIFDSC and AIFDCE. The relative cerebral blood volume (rCBV) was obtained from DSC-MRI. Intraclass correlation coefficients (ICC) and ROC curves were used to assess the reliability and diagnostic accuracy of individual parameters. The mean Ktrans, vp, and ve values revealed better ICCs with AIFDSC than with AIFDCE (Ktrans, 0.911 vs 0.355; vp, 0.766 vs 0.503; ve, 0.758 vs 0.657, respectively). For differentiating all glioblastomas from PCNSL, the mean rCBV (AUC = 0.856) was more accurate than the AIFDSC-driven mean Ktrans, which had the largest AUC (0.711) among the DCE-derived parameters (p = 0.02). However, for glioblastomas with low rCBV (≤ 75th percentile of PCNSL; n = 30), the AIFDSC-driven mean Ktrans and vp were more accurate than rCBV (AUC: Ktrans, 0.807 vs rCBV, 0.515, p = 0.004; vp, 0.715 vs rCBV, p = 0.045). DCE-derived PK parameters using the AIFDSC showed improved reliability and diagnostic accuracy for differentiating glioblastoma with low rCBV from PCNSL. • An accurate differential diagnosis of glioblastoma and PCNSL is crucial because of different therapeutic strategies. • In contrast to the rCBV from DSC-MRI, another perfusion imaging technique, the DCE parameters for the differential diagnosis have been limited because of the low reliability of AIFs from DCE-MRI. • When we analyzed DCE-MRI data using AIFs from DSC-MRI (AIFDSC), AIFDSC-driven DCE parameters showed improved reliability and better diagnostic accuracy than rCBV for differentiating glioblastoma with low rCBV from PCNSL.

A variety of microRNAs (miRNAs) are involved in the occurrence and development of hepatocellular carcinoma (HCC). However, the role of miR‐10a‐5p in the progression of HCC remains unclear. Therefore, the purpose of this study was to determine the role of miR‐10a‐5p in the development of HCC and the possible molecular mechanism. miR‐10a‐5p expression in HCC tissues and plasma from patients was detected by quantitative real‐time polymerase chain reaction. Migratory changes in HCC cells were detected after the overexpression of miR‐10a‐5p. Epithelial–mesenchymal transition (EMT)‐related proteins were detected by Western blot. Finally, through luciferase assay and rescue experiments, the mechanism by which miR‐10a‐5p regulates its downstream gene, human spindle and kinetochore‐associated complex subunit 1, SKA1 and the interaction between these molecules in the development of HCC were determined. The expression of miR‐10a‐5p was markedly downregulated in HCC tissues, cell lines, and plasma. The overexpression of miR‐10a‐5p significantly inhibited the migration, invasion, and EMT of HCC cells. Furthermore, SKA1 was shown to be a downstream gene of miR‐10a‐5p. SKA1 silencing had the same effect as miR‐10a‐5p overexpression in HCC. In particular, the overexpression of SKA1 reversed the inhibitory effects of miR‐10a‐5p in HCC. Taken together, low miR‐10a‐5p expression is associated with HCC progression. miR‐10a‐5p inhibits the malignant development of HCC by negatively regulating SKA1.

To explore cerebrovascular reservoir (CVR) and arterial transit time (ATT) changes using acetazolamide-challenged multi-phase arterial spin labeling (MP-ASL) perfusion-weighted MRI in chronic cerebrovascular steno-occlusive disease.This retrospective study enrolled patients with chronic steno-occlusion who underwent acetazolamide-challenged MP-ASL between June 2019 and October 2020. Cerebral blood flow, CVR, basal ATT, and ATT changes associated with severe stenosis, total occlusion, and chronic infarction lesions were compared.There were 32 patients (5 with bilateral steno-occlusion) in our study sample. The CVR was significantly reduced during total occlusion compared with severe stenosis (26.2% ± 28.8% vs. 41.4% ± 34.1%, respectively,Acetazolamide-challenged MP-ASL provides an MRI-based CVR evaluation tool for chronic steno-occlusive disease.만성 뇌동맥 협착-폐색증에서 아세타졸아미드 부하 다상 동맥 스핀 표지(multi-phase arterial spin labeling; 이하 MP-ASL) 자기공명관류영상을 이용하여 뇌혈류 예비능(cerebrovascular reservoir; 이하 CVR)과 동맥 통과 시간(arterial transit time; 이하 ATT)의 변화를 탐색하였다.2019년 6월부터 2020년 10월까지 새롭게 만성 협착-폐색증으로 진단되어 아세타 졸아미드 부하 MP-ASL을 시행한 환자를 후향적으로 모집하였다. 부하 전후의 뇌혈류(cerebral blood flow), CVR, 부하전 ATT 및 부하 전후의 ATT 변화량을 중증 협착과 완전 폐색간, 만성 뇌경색 병변의 유무에 따라 비교하였다.5명의 양측성 협착-폐색을 포함하여 총 32명의 환자가 본 연구에 포함되었다. CVR은 완전 폐색에서 중증 협착보다 유의하게 낮았다(26.2% ± 28.8% vs. 41.4% ± 34.1%,만성 협착-폐색증에서 아세타졸아미드 부하 MP-ASL 검사는 MRI 기반의 CVR 평가 도구로 사용될 수 있다.

Highly soluble d8-d10 heteronuclear phosphors afford an alternative approach to achieve high-efficiency organic light-emitting diodes (OLEDs) through a solution process. In this work, four highly phosphorescent d8-d10 heteronuclear complexes with significant Pt-Au interactions were prepared. By judicious selection of sterically hindered and π-conjugated substituents in triphosphine ligands, the phosphorescence is dramatically promoted through effectively prohibiting nonradiative thermal relaxation with an efficiency of 0.94-0.99 in doping films. Exploiting highly emissive Pt-Au complexes as phosphorescent dopants, ultrahigh-efficiency solution-processed OLEDs were attained. The peak current efficiency, power efficiency, and external quantum efficiency are 96.2 cd A-1, 65.0 lm W-1, and 26.4% for the green-emitting PtAu2 phosphor and 68.6 cd A-1, 42.5 lm W-1, and 25.1% for the orange-emitting Pt2Au phosphor, which represent the state-of-art for solution-processed OLEDs based on non-iridium phosphors.

BACKGROUND AND PURPOSE: O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in primary and recurrent glioblastoma may change during treatment. The purpose of this study was to correlate MGMT promoter methylation status changes with DWI and DSC PWI features in patients with recurrent glioblastoma after standard treatment. MATERIALS AND METHODS: Between January 2008 and November 2016, forty patients with histologically confirmed recurrent glioblastoma were enrolled. Patients were divided into 3 groups according to the MGMT promoter methylation status for the initial and recurrent tumors: 2 groups whose MGMT promoter methylation status remained, group methylated (n = 13) or group unmethylated (n = 18), and 1 group whose MGMT promoter methylation status changed from methylated to unmethylated (n = 9). Normalized ADC and normalized relative CBV values were obtained from both the enhancing and nonenhancing regions, from which histogram parameters were calculated. The ANOVA and the Kruskal-Wallis test followed by post hoc tests were performed to compare histogram parameters among the 3 groups. The t test and Mann-Whitney U test were used to compare parameters between group methylated and group methylated to unmethylated. Receiver operating characteristic curve analysis was used to measure the predictive performance of the normalized relative CBV values between the 2 groups. RESULTS: Group methylated to unmethylated showed significantly higher means and 90th and 95th percentiles of the cumulative normalized relative CBV values of the nonenhancing region of the initial tumor than group methylated and group unmethylated (all P < .05). The mean normalized relative CBV value of the nonenhancing region of the initial tumor was the best predictor of methylation status change (P < .001), with a sensitivity of 77.78% and specificity of 92.31% at a cutoff value of 2.594. CONCLUSIONS: MGMT promoter methylation status might change in recurrent glioblastoma after standard treatment. The normalized relative CBV values of the nonenhancing region at the first preoperative MR imaging were higher in the MGMT promoter methylation change group from methylation to unmethylation in recurrent glioblastoma.

Background Pre-Fontan risk stratification is still less than optimal. We aimed to evaluate the effectiveness of intraoperative pulmonary flow study (IOFS), in combination with conventional preoperative evaluation, in the identification of high-risk candidates for the Fontan operation. Method Data from 37 patients (age: 38.1 ± 4.9 months) who underwent the Fontan operation with IOFS were retrospectively reviewed. After anastomosing the Gore-Tex vascular graft to the confluent pulmonary artery, IOFS was performed through the graft at various cardiac indices (CI) (1–4 L/min/m2) generated from a roller pump. Mean pulmonary artery pressure (mPAP) and left atrial pressure (LAP) were recorded. The patients were divided into two groups: those who required Fontan circuit fenestration (group Ff) and those who did not (group Fn). Results Eleven patients (29.7%) required fenestration, intraoperatively (n = 4) and postoperatively (n = 7), due to hemodynamic instability. Heterotaxy syndrome (P = 0.005) and atrioventricular valvar regurgitation (P = 0.04) were more frequent, and ventricle posterior wall thickness (VPWT) was higher (P = 0.024) in group Ff. On IOFS, the increase in mPAP by CI was sharper in group Ff than in group Fn (P Conclusions IOFS may be helpful to identify high-risk Fontan candidates, and high mPAP at CI of 3.0 L/min/m2 on IOFS is a significant predictor of the requirement for fenestration. VPWT is an important preoperative risk factor which correlates with the IOFS results.

Previous reports indicate that the decreased left ventricular global longitudinal strain (LVGLS) seen in the early postoperative period of pediatric heart transplant patients generally recovers over the course of 1–2 years. In this study, we investigate the predictive capacity of preoperative parameters on the LVGLS decline seen at 1 month post transplant. Forty-six transplant subjects with 2D echocardiographic images sufficient for speckle tracking echocardiography were enrolled. We excluded patients diagnosed with cardiac allograft vasculopathy or with an episode of rejection 1 month before or after their echocardiographic examinations. The mean LVGLS was significantly reduced at 1 month when compared to 1 year following transplant (− 15.5% vs. − 19.4%, respectively, p

We sought to determine the impact of juxtaductal stenosis (JDS) on branch pulmonary artery (PA) growth after systemic-to-pulmonary shunt (SPS) placement without pulmonary arterioplasty (ie the ‘shunt-only’ strategy). This was a retrospective review of 91 patients, 54 (59.3%) with pulmonary atresia and 27 (29.7%) with a functionally single ventricle, who underwent neonatal SPS placement without pulmonary arterioplasty between 2008 and 2017. The median age and body weight at SPS procedure were 16 day's (interquartile range [IQR], 11–22) and 3.10 kg (IQR: 2.85–3.40), respectively. All patients had pre-SPS computed tomography (CT) followed by post-SPS CT at a median interval of 5.8 months’ (IQR: 4.5–7.2). The ratio of the diameters of the juxtaductal PA over the non−SPS−side hilar PA (JD and/or PA) on preoperative CT—a surrogate for JDS severity—was 0.93 (IQR: 0.67–1.09). The median diameter (Z) of the SPS−side and non−SPS-side PA on postoperative CT were 1.0 (IQR: −0.07–1.73) and 0.99 (IQR: −0.45–1.70), respectively. The pulmonary artery index (Nakata index) increased significantly from 124.0 ± 50.2 mm2/m2 to 240.8 ± 88.7 mm2/m2 (P

In this work, rational design of highly soluble and phosphorescent Ag–Au cluster complexes with exceptional [2]catenane structures is conducted using 1,8-diethynyl-9H-carbazole (H3decz) as a rigid ...

Background We aimed to assess the clinical outcomes of patients who underwent surgical repair of Kommerell diverticulum (KD) with individualized surgical methods. Methods A retrospective analysis was performed of adult patients (aged ≥17 years) who underwent surgery to treat KD between June 2008 and October 2019. Results Nine patients (median age, 45 years; range, 19-67 years; 7 men) underwent surgical repair. The indications for surgical therapy were acute aortic dissection in 2 patients, the presence of compressive symptoms due to dilated KD in 4 patients, and aneurysm growth in 3 patients. Various surgical techniques were used: (1) resection of the diverticulum stump and revascularization of the aberrant subclavian artery (n=3), (2) one-stage total-arch replacement including the diverticulum segment (n=3), and (3) hybrid repair (n=3). Early mortality occurred in 1 case of hybrid repair. Transient paraparesis occurred in a patient who underwent total arch repair as part of complicated acute aortic dissection. During follow-up (median duration, 30 months; range, 7-130 months), no late death or associated aortic complications were documented. All survivors were free from symptoms and had no abnormal findings on follow-up computed tomography. Conclusion With a customized surgical approach and appropriate consideration of patient- specific anatomy and associated comorbidities, KD can be repaired with favorable outcomes.

A new type A botulinum toxin (BoNT/A) preparation, JTM201 (NCBI chromosomal DNA ID: CP046450), has been developed, which comprises 900-kDa complexed toxin purified from Clostridium botulinum (strain: NCTC13319), but its safety and efficacy have not yet been evaluated. The purpose of this study was to evaluate the long-term efficacy and safety of JTM201 at different concentrations in comparison to another commercially available BoNT/A product, Botox® (onabotulinumtoxin A, ONA), using a mouse model. The LD50 of JTM201 was similar to that of ONA, but the intrinsic activity of JTM201 was higher than that of ONA. Functional recovery of the nerves and muscles in SKH-1 mice after administration of the two BoNT/A preparations (JTM201 and ONA) to the right gastrocnemius muscle was observed over 24 weeks. In addition, JTM201 did not induce any skin or muscle inflammatory response in 24 weeks. Paralysis induced by neurotransmitter blockade after JTM201 administration was comparable to that of ONA treatment. Both muscle weight and volume decreased in a concentration-dependent manner following JTM201 or ONA toxin injection until week 4. Reduced muscle fiber size due to atrophy and consequent fibrosis were detected following injection of JTM201 or ONA. Moreover, we assessed the extent of diffusion of JTM201 or ONA to the tibialis anterior and quadriceps femoris muscles, demonstrating limited diffusion to off-target muscles. In conclusion, JTM201 demonstrated long-term efficacy and safety equivalent to those of ONA based on compound muscle action potential, muscle volume, and histology analyses. These data suggest that JTM201 is a new BoNT/A formulation with safety and efficacy comparable to those of ONA.

Background Prolonged ischemic time is a risk factor for primary graft dysfunction in patients who undergo heart transplantation. We investigated the effect of a supplemental cardioplegia infusion before anastomosis in patients with long ischemic times. Methods We identified 236 consecutive patients who underwent orthotopic heart transplantation between February 2010 and December 2014. Among them, the patients with total ischemic times of longer than 3 hours (n=59) were categorized based on whether they were administered a complementary cardioplegia solution (CPS) immediately before implantation (CPS+, n=30; CPS-, n=29). Results The mean total ischemic times in the CPS+ and CPS- groups were 238.1±30.1 minutes and 230.1±28.2 minutes, respectively (p=0.3). The incidence of left ventricular primary graft dysfunction (CPS+, n=6 [20.0%]; CPS-, n=5 [17.2%]; p=0.79) was comparable between the groups. In the Kaplan-Meier survival analysis, no significant difference in overall survival at 5 years was observed between the CPS+ and CPS- groups (83.1%±6.9% vs. 89.7%±5.7%, respectively; log-rank p=0.7). No inter-group differences in early mortality (CPS+, n=0; CPS-, n=1 [3.4%]; p=0.98) or complications were observed. Conclusion The additional infusion of a cardioplegia solution immediately before implantation in patients with longer ischemic times is a simple, reproducible, and safe procedure. However, we did not observe benefits of this strategy in the present study.

Purpose : To compare the differences in visual quality and accommodative functions after wearing single and multiple front surface aspheric functional contact lenses in the twenties having sufficient accommodation. Methods : Thirteen subjects(21.38±0.65 years) were evaluated for visual acuity, contrast sensitivity, stray light, total higher order aberrations, spherical aberration, coma aberration, accommodative response, binocular accommodative facility and near point of accommodation after wearing two types of contact lenses, respectively. Results : There was no significant difference in visual acuity, contrast sensitivity, stray light, total high order aberration, spherical aberration and binocular accommodative facility. Coma aberration increased slightly in wearing multi front aspheric functional contact lenses at 4 and 5 mm pupil size(p=0.037). Accommodative response(p=0.006) and near point of accommodation(p=0.005) were significantly reduced and shorter in wearing multi front aspheric functional contact lens. Conclusion : There was no difference in visual quality in wearing multiple front aspheric functional contact lenses compared to in wearing single front aspheric contact lenses. But it is thought to be useful as a functional contact lens for young adults because it has the effect on reducing the accommodative burden.

Organic semiconductors (OSCs) are of interest for replacing traditional Si-based semiconductors as their flexibility and transparency enable new applications. The properties of OSC materials greatly depend on their orientation and molecular arrangement, which are strongly dependent on the underlying substrate material. Hence, in this study, in situ ultraviolet photoelectron spectroscopy (UPS) is used to elucidate the effect of the substrate on OSC orientation. Two types of OSCs, namely those with shape anisotropy (pentacene, dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene, and dibenzothiopheno[6,5-b:6',5'-f]thieno[3,2-b]thiophene) and those with shape isotropy (N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine, tris(4-carbazoyl-9-ylphenyl)amine, and [6,6]-phenyl C71 butyric acid methyl ester), are deposited on different electrode materials. The differences in the UPS spectra of these materials are observed directly. In general, the orientation of anisotropic OSC molecules significantly depends on the substrate properties, while that of the isotropic ones do not. All the anisotropic OSC molecules grown on poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT:PSS) electrodes show a greater degree of molecular ordering than those grown on Au and multiwalled carbon nanotube/PEDOT:PSS electrodes. The molecular arrangements within the OSC/electrode structures are reflected in the energy-level shifts in the corresponding UPS spectra and hence in the electronic configurations. The results of this study should aid the design and synthesis of OSC materials with configurations suitable for organic electronic devices.

Down syndrome (DS) is the most common genetic cause of developmental disabilities. Advanced analysis of brain magnetic resonance imaging (MRI) has been used to find brain abnormalities and their relationship to neurocognitive impairments in children and adolescents with DS. Because genetic factors affect brain development in early fetal life, there is a growing interest in analyzing brains from living fetuses with DS. In this study, we investigated regional sulcal folding depth as well as global cortical gyrification from fetal brain MRIs. Nine fetuses with DS (29.1 ± 4.24 gestational weeks [mean ± standard deviation]) were compared with 17 typically developing [TD] fetuses (28.4 ± 3.44). Fetuses with DS showed lower whole-brain average sulcal depths and gyrification index than TD fetuses. Significant decreases in sulcal depth were found in bilateral Sylvian fissures and right central and parieto-occipital sulci. On the other hand, significantly increased sulcal depth was shown in the left superior temporal sulcus, which is related to atypical hemispheric asymmetry of cortical folding. Moreover, these group differences increased as gestation progressed. This study demonstrates that regional sulcal depth is a sensitive marker for detecting alterations of cortical development in DS during fetal life, which may be associated with later neurocognitive impairment.

The design, synthesis, and characterization of two novel nonfullerene acceptors (M8 and M34) based on ladder-type heteroheptacenes with different heterocycles are reported. Replacing the furan heterocycles with the thiophene heterocycles in the heteroheptacene backbone leads to a hypsochromically shifted absorption band and greatly improved carrier transport for the resulting nonfullerene acceptor (M34) although the π-π-stacking distances are barely affected. Bulk-heterojunction polymer solar cells fabricated from M34 and a wide band gap polymer (PM6) as the donor showed a best power conversion efficiency (PCE) of 15.24 % with an open circuit voltage (VOC ) of 0.91 V, much higher than a PCE of 4.21 % and a VOC of 0.83 V for the counterparts based on M8:PM6. These results highlight the importance of key atoms in the construction of high-performance nonfullerene acceptors.

Purpose Circular RNAs (circRNAs) are a new class of RNA molecules whose function is largely unknown. There is a growing evidence that circRNAs play an important regulatory role in the progression of a variety of human cancers. However, the exact roles and the mechanisms of circRNAs in gastric cancer are not clear. In this study, we aimed to elucidate the mechanism of hsa_circ_0005556. Materials and methods Real-time quantitative polymerase chain reaction was used to detect the expression of hsa_circ_0005556, miR-4270, and matrix metalloproteinase-19 (MMP19) in gastric cancer tissues and cell lines. The expression of hsa_circ_0005556 in gastric cancer cells was silenced by lentivirus, and cell proliferation, invasion, migration, and tumorigenesis in nude mice were assessed to evaluate the function of hsa_circ_0005556 in gastric cancer. Results The expression of hsa_circ_0005556 in gastric cancer tissues and gastric cancer cell lines was higher compared to normal controls. In vitro, the downregulation of hsa_circ_0005556 significantly inhibited proliferation, migration, and invasion of gastric cancer cells. In vivo, the downregulation of hsa_circ_0005556 suppressed tumor growth in nude mice. Conclusions Our study shows that the hsa_circ_0005556/miR-4270/MMP19 axis is involved in proliferation, migration, and invasion of gastric cancer cells through the competing endogenous RNA (ceRNA) mechanism.

Objective To assess the predictive ability of regional volume information provided by fully automated brain segmentation software for cerebral amyloid positivity in mild cognitive impairment (MCI). Methods This study included 130 subjects with amnestic MCI who participated in the Korean brain aging study of early diagnosis and prediction of Alzheimer's disease, an ongoing prospective cohort. All participants underwent comprehensive clinical assessment as well as 11C-labeled Pittsburgh compound PET/MRI scans. The predictive ability of volumetric results provided by automated brain segmentation software was evaluated using binary logistic regression and receiver operating characteristic curve analysis. Results Subjects were divided into two groups: one with Aβ deposition (58 subjects) and one without Aβ deposition (72 subjects). Among the varied volumetric information provided, the hippocampal volume percentage of intracranial volume (%HC/ICV), normative percentiles of hippocampal volume (HCnorm), and gray matter volume were associated with amyloid-β (Aβ) positivity (all P < 0.01). Multivariate analyses revealed that both %HC/ICV and HCnorm were independent significant predictors of Aβ positivity (all P < 0.001). In addition, prediction scores derived from %HC/ICV with age and HCnorm showed moderate accuracy in predicting Aβ positivity in MCI subjects (the areas under the curve: 0.739 and 0.723, respectively). Conclusion Relative hippocampal volume measures provided by automated brain segmentation software can be useful for screening cerebral Aβ positivity in clinical practice for patients with amnestic MCI. The information may also help clinicians interpret structural MRI to predict outcomes and determine early intervention for delaying the progression to Alzheimer's disease dementia.

Background The optimal surgical strategy for pulmonary atresia with ventricular septal defect (PA/VSD) in neonates and young infants is controversial. Staged repair may be associated with a higher risk of inter-stage mortality, while primary repair may lead to frequent post-repair re-interventions. Methods From 2004 to 2017, 65 patients with PA/VSD who underwent surgical intervention before 90 days of age were identified and enrolled in this retrospective study. The cohort was divided into two groups: group-SR, who underwent initial palliation with staged repair (n = 50), and group-PR who underwent primary repair (n = 15). Results There were three post-palliation in-hospital mortalities, four inter-stage mortalities, and one post-repair in-hospital mortality in group-SR. In group-PR, there was one in-hospital death and one late death. Five-year survival rates were comparable between the two groups (group-SR: 83.6%; group-PR: 86.7%; p = 0.754). During the median follow-up duration of 44.7 months (Inter-quartile range, 19–109 months), 40 post-repair re-interventions (22 in group-SR, 18 in group-PR) were performed in 26 patients (18 in group-SR, 8 in group-PR). On Cox proportional hazards model, primary repair was identified as the only risk factor for decreased time to death/1st post-repair re-intervention (Hazard ratio (HR): 2.3, p = 0.049) and death/2nd post-repair re-intervention (HR 2.91, p = 0.033). Conclusions A staged repair strategy, compared with primary repair, was associated with comparable overall survival with less frequent re-interventions after repair in young infants with PA/VSD. Lowering the inter-stage mortality after initial palliation by vigilant outpatient care and aggressive home monitoring may be the key to better surgical outcomes in this subset. Graphic Abstract Surgical outcomes of PA with VSD according to the surgical strategies. Patient 1 (birth weight: 2.7 kg) underwent primary Rastelli-type repair at post-natal day # 50 (body weight: 3.8 kg) using Contegra® 12 mm. The postoperative course was rocky, with long ventilatory support (10 days), ICU stay (14 days), and hospital stay (20 days). Cardiac CT scan at 9 months post-repair showed severe branch pulmonary artery stenosis, which necessitated LPA stenting at 12 months post-repair and RV-PA conduit replacement with extensive pulmonary artery reconstruction at 25 months post-repair. Patient 2 (birth weight: 2.5 kg) underwent RMBT at post-natal day #30 (body weight: 3.4 kg) using 4 mm PTFE vascular graft and staged Rastelli-type repair at post-natal 11 months using a hand-made Gore-Tex valved conduit (14 mm). No post-repair re-intervention has been performed. Cardiac CT scan at 90 months post-repair showed no branch pulmonary artery stenosis.CT computed tomography, ICU intensive care unit, LPA left pulmonary artery, PA pulmonary atresia, PTFE polytetrafluoroethylene, RMBT right modified Blalock–Taussig shunt, RV-PA right ventricle to pulmonary artery, VSD ventricular septal defect.

In this study, a new functional thiol with a pentafluorophenyl group was synthesized for the surface modification of CdSe quantum-dot floating layers; this was aimed at the fabrication of organic field-effect transistors (OFETs). The dipole moments and surface properties of the fluorinated thiols were used to control the transistor operations; these thiols acted as surface modifiers of the CdSe quantum-dot floating layers in the OFETs. Further, the new functional thiol exhibited a larger dipole moment than that of the commercial 2,3,4,5,6-pentafluorothiophenol. The OFET comprising the new functional thiol with the pentafluorophenyl group functioned as a normally ON transistor and exhibited bistable current states during nondestructive reading. In addition, it exhibited sensitive responses to electrical-only and light-only biases, which demonstrates its feasibility for light-responsive flash memory applications.

Hypogenesis (hCC) and dysgenesis (dCC) of the corpus callosum (CC) are characterized by its smaller size or absence. The outcomes of these patients vary considerably and are unrelated to the size of the CC abnormality. The aim of the current study was to characterize the sulcal pattern in children with hCC and dCC and to explore its relation to clinical outcome. We used quantitative sulcal pattern analysis that measures deviation (similarity index, SI) of the composite or individual sulcal features (position, depth, area, and graph topology) compared to the control group. We calculated SI for each hemisphere and lobe in 11 children with CC disorder (hCC = 4, dCC = 7) and 15 controls. hCC and dCC had smaller hemispheric SI compared to controls. dCC subjects had smaller regional SI in the frontal and occipital lobes, which were driven by a smaller SI in a position or a graph topology. The significantly decreased SI gradient was found across groups only in the sulcal graph topology of the temporal lobes (controls > hCC > dCC) and was related to clinical outcome. Our results suggest that careful examination of sulcal pattern in hCC and dCC patients could be a useful biomarker of outcome.

Younger gestational age (GA) is known to be associated with worse outcomes after congenital cardiac surgery. We sought to determine the impact of GA on surgical outcomes of single-ventricle palliation.Among the 284 patients with functionally single ventricle who were born between January 2005 and December 2014, 50 neonates were born prematurely (GA37 weeks) and 113 neonates in the early term period (37 weeks ≤ GA39 weeks). Initial palliation was required in 251 patients, whereas 33 patients received primary bidirectional cavopulmonary anastomosis (BCPA).BCPA and the completion Fontan operation were performed in 200 and 169 patients, respectively. Overall survival at 5 years were 62.5% ± 2.9%. On Cox regression younger GA (hazard ratio, 1.14 per 1-week decrease; P = .007) was identified as a risk factor for increased interstage mortality (ISM) between initial palliation and BCPA. On subgroup analysis of the preterm or early-term patients with initial palliation (n = 145), younger postmenstrual age at initial palliation was associated with increased ISM before BCPA (hazard ratio, 1.18; P = .005). After BCPA, however, younger GA did not increase the risk of ISM between BCPA and the Fontan operation (P = .47).Younger GA is a risk factor for ISM between initial palliation and BCPA. Deferral of initial palliation may be beneficial to decrease the risk of ISM in patients who were born at preterm or early term. Adverse effects of younger GA on survival disappeared once BCPA was performed.

As low-dimensional lead-free hybrids with higher stability and lower toxicity than those of three-dimensional lead perovskites, organic antimony(III) halides show great application potential in opt-electronic field owing to diverse topologies along with exceptional optical properties. We report herein an antimony(III) hybrid (MePPh3 )2 SbCl5 with a zero-dimensional (0D) structure, which exhibits brilliant orange emission peaked at 593 nm with near-unity photoluminescent quantum yield (99.4 %). The characterization of photophysical properties demonstrates that the broadband emission with a microsecond lifetime (3.24 μs) arises from self-trapped emission (STE). Electrically driven organic light-emitting diodes (OLEDs) based on neat and doped films of (MePPh3 )2 SbCl5 were fabricated. The doped devices show significant improvement in comparison to non-doped OLEDs. Owing to the much improved surface morphology and balanced carrier transport in light-emitting layers of doped devices, the peak luminance, current efficiency (CE) and external quantum efficiency (EQE) are boosted from 82 cd m-2 to 3500 cd m-2 , 1.1 cd A-1 to 6.8 cd A-1 , and 0.7 % to 3.1 % relative to non-doped devices, respectively.

The accurate prediction of fetal brain age using magnetic resonance imaging (MRI) may contribute to the identification of brain abnormalities and the risk of adverse developmental outcomes. This study aimed to propose a method for predicting fetal brain age using MRIs from 220 healthy fetuses between 15.9 and 38.7 weeks of gestational age (GA). We built a 2D single-channel convolutional neural network (CNN) with multiplanar MRI slices in different orthogonal planes without correction for interslice motion. In each fetus, multiple age predictions from different slices were generated, and the brain age was obtained using the mode that determined the most frequent value among the multiple predictions from the 2D single-channel CNN. We obtained a mean absolute error (MAE) of 0.125 weeks (0.875 days) between the GA and brain age across the fetuses. The use of multiplanar slices achieved significantly lower prediction error and its variance than the use of a single slice and a single MRI stack. Our 2D single-channel CNN with multiplanar slices yielded a significantly lower stack-wise MAE (0.304 weeks) than the 2D multi-channel (MAE = 0.979, p < 0.001) and 3D (MAE = 1.114, p < 0.001) CNNs. The saliency maps from our method indicated that the anatomical information describing the cortex and ventricles was the primary contributor to brain age prediction. With the application of the proposed method to external MRIs from 21 healthy fetuses, we obtained an MAE of 0.508 weeks. Based on the external MRIs, we found that the stack-wise MAE of the 2D single-channel CNN (0.743 weeks) was significantly lower than those of the 2D multi-channel (1.466 weeks, p < 0.001) and 3D (1.241 weeks, p < 0.001) CNNs. These results demonstrate that our method with multiplanar slices accurately predicts fetal brain age without the need for increased dimensionality or complex MRI preprocessing steps.

Background:This study aimed to determine the effect of donor-transmitted atherosclerosis on the late aggravation of cardiac allograft vasculopathy in paediatric heart recipients aged ≥7 years.Methods:In total, 48 patients were included and 23 had donor-transmitted atherosclerosis (baseline maximal intimal thickness of >0.5 mm on intravascular ultrasonography). Logistic regression analyses were performed to identify risk factors for donor-transmitted atherosclerosis. Rates of survival free from the late aggravation of cardiac allograft vasculopathy (new or worsening cardiac allograft vasculopathy on following angiograms, starting 1 year after transplantation) in each patient group were estimated using the Kaplan–Meier method and compared using the log-rank test. The effect of the results of intravascular ultrasonography at 1 year after transplantation on the late aggravation of cardiac allograft vasculopathy, correcting for possible covariates including donor-transmitted atherosclerosis, was examined using the Cox proportional hazards model.Results:The mean follow-up duration after transplantation was 5.97 ± 3.58 years. The log-rank test showed that patients with donor-transmitted atherosclerosis had worse survival outcomes than those without (p = 0.008). Per the multivariate model considering the difference of maximal intimal thickness between baseline and 1 year following transplantation (hazard ratio, 22.985; 95% confidence interval, 1.948–271.250; p = 0.013), donor-transmitted atherosclerosis was a significant covariate (hazard ratio, 4.013; 95% confidence interval, 1.047–15.376; p = 0.043).Conclusion:Paediatric heart transplantation recipients with donor-transmitted atherosclerosis aged ≥7 years had worse late cardiac allograft vasculopathy aggravation-free survival outcomes.

Congenital atresia of the left main coronary artery (LMCA) is an extremely rare coronary anomaly that necessitates surgical correction. Patients with LMCA atresia may have various clinical symptoms, which are determined by the degree of collateral vessel development from the right coronary system, the metabolic demands of the heart, and concomitant mitral insufficiency caused by myocardial ischemia. Unlike in adults, there are limited surgical options for coronary artery disease in children. Herein, we report a case of LMCA atresia with mitral regurgitation in a 19-month-old child that was successfully corrected by coronary artery bypass grafting and mitral valve repair.

In this paper, design criteria are proposed for an aircraft morphing wing skin and conventional lattice structures are evaluated against the design criteria. Although the structural deformation and...

In this paper, a sensing interrogation scheme for Sagnac interferometer (SI) with polarization maintaining fiber (PMF) by using microwave photonic filtering technique has been theoretically analyzed and experimentally demonstrated. In our experiment, the SI acts as the sensing element as well as a spectrum slicer in the single-passband microwave photonic filter (MPF). The central frequency of the MPF’s passband moves to lower frequency when the temperature is increased. Hence, the measurands can be demodulated by monitoring the central frequency of the MPF’s passband in Radio Frequency (RF) domain. Comparing with the interrogation by tracking dip wavelength of the interference patterns in the optical domain and using the product of birefringence and the length of PMF in the SI structure for interrogation, the proposed interrogation system converts the wavelength variations of the interferometer patterns in optical domain to the frequency changes in electronic domain directly by utilizing opto-electronic devices, and thus has an unlimited measurement range, less limitations by resolution limitation of measuring instruments and less cross-sensitivity problems.

Garnet-structured oxide electrolytes (Li7La3Zr2O12, LLZO) have significant advantage of being chemically and electrochemically stable against Li metals and allow implementation in Li metal batteries. However, a short-circuit failure due to Li penetration through the LLZO electrolyte has remained a crucial issue for safety and is a major hurdle for Li-based batteries to overcome. In, we investigated a mechanism of Li dendrite formation for the crystalline Ta-doped LLZO (LLZTO) electrolyte by examining their energy band structures and defect states using reflection electron energy loss spectroscopy (REELS), scanning photoelectron microscopy (SPEM), and nanoscale charge-based deep level transient spectroscopy (Nano Q-DLTS) techniques. The experimental results revealed that the Schottky barrier height (SBH) was lowered by 0.5 eV due to defect states localized in grain boundaries and that the metallic Li propagation along the grain boundaries is caused by the SBH reduction. Based on analytical results, the laser annealing of LLZTO was performed via bandgap engineering method to suppress the Li dendrite formation by forming a mixed surface layer of amorphous LLZTO and Li2O2, which has a wide bandgap to block the electron injection into the grain boundaries. The electrochemical measurements of laser-treated LLZTO demonstrated that the stability and cycling performance were significantly improved. This study sheds light on the importance of electronic structure, in particular, the defect states to develop high-performance oxide solid electrolytes for Li metal batteries and the practicality of surface modification by laser treatment.

Piezoelectric energy harvesters (PEHs) are widely used to convert energy from a piezoelectric transducer into a stable DC form, which enables low-power IoT devices to have an unlimited operating life without using batteries. Under weak excitation conditions, however, the power-extraction efficiency of conventional PEHs is too low to provide power even to low-power IoT devices that requires low operation voltages less than 2 V. This paper proposes an asymmetric synchronous electric charge extraction (ASECE) scheme that improves the extraction efficiency of PEHs at low output voltages under weak excitation. The proposed ASECE is implemented using 0.18 μm CMOS technology. The figure-of-merits (FOMs) of the proposed ASECE while operating under 2 V of output voltage are 7.14 and 6.24 at weak and strong excitations, respectively. The maximum FOM for various different excitation levels is observed to be as high as 7.7. The proposed ASECE is superior to prior art with respect to FOM, by at least 1.15×, 1.63×, and 2.21× under 2 V, 1 V, and 0.5 V outputs, respectively, under strong excitation.