COVID-19 infection in patients with end-stage kidney disease undergoing renal replacement therapies in Korea.

Background: The global coronavirus disease 2019 (COVID-19) pandemic has placed patients with end-stage kidney disease (ESKD) at heightened risk owing to their vulnerability to infections. Our study focused on patients with ESKD, examining COVID-19 incidence, hospitalization, and mortality in relation to their renal replacement therapy (RRT) type and identifying factors influencing COVID-19 hospitalization. Methods: We conducted a retrospective cohort study using health insurance claims data from the Health Insurance Review and Assessment Service for patients with ESKD between July 2017 and June 2022. COVID-19 data for the general population were sourced from the Korea Disease Control and Prevention Agency. Results: Patients undergoing hemodialysis (HD) constituted 90.7% of the cohort, followed by kidney transplantation (KT) recipients and peritoneal dialysis (PD). After adjusting for every 10,000 individuals, KT recipients exhibited the highest COVID-19 incidence, followed by those undergoing HD and PD, whereas the general population showed a higher infection rate of 43.64. Patients undergoing HD had the highest hospitalization rates, followed by KT recipients and those undergoing PD. The mortality rate per 10,000 individuals was highest in HD, followed by PD, the general population, and KT. Multivariate analysis indicated that age, RRT duration, residence in a nursing hospital, and comorbidities were associated with COVID-19 hospitalization. Conclusion: Among RRT modalities, KT recipients displayed the highest COVID-19 incidence, whereas those undergoing HD exhibited the highest hospitalization and mortality rates. This study contributes to our understanding of infectious diseases in patients on RRT and aids in preparedness for future infectious disease outbreaks.

The karyometric signature is altered in fallopian tubes with serous tubal intraepithelial carcinoma.

OBJECTIVE: Recent evidence suggests that the fimbriated end of the fallopian tube harbors the precursor cells for many high-grade ovarian cancers, opening the door for development of better screening methods that directly assess the fallopian tube in women at risk for malignancy. Previously we have shown that the karyometric signature is abnormal in the fallopian tube epithelium in women at hereditary risk of ovarian cancer. In this study, we sought to determine whether the karyometric signature in serous tubal intraepithelial carcinoma (STIC) is significantly different from normal, and whether an abnormal karyometric signature can be detected in histologically normal tubal epithelial cells adjacent to STIC lesions. METHODS: The karyometric signature was measured in epithelial cells from the proximal and fimbriated portion of the fallopian tube in fallopian tube specimens removed from women at: 1) average risk for ovarian cancer undergoing surgery for benign gynecologic indications (n = 37), 2) hereditary risk of ovarian cancer (germline BRCA alterations) undergoing risk-reducing surgery (n = 44), and 3) diagnosed with fimbrial STICs (n = 17). RESULTS: The karyometric signature in tubes with fimbrial STICs differed from that of tubes with benign histology. The degree of karyometric alteration increased with increasing proximity to fimbrial STICs, ranging from moderate in the proximal portion of the tube, to greatest in both normal appearing fimbrial cells near STICs as well as in fimbrial STIC lesions. CONCLUSION: These data demonstrate an abnormal karyometric signature in STICs that may extend beyond the STIC, potentially providing an opportunity for early detection of fallopian tube neoplasia.

Clinical and economic burden of immune tolerance induction in entire patients with hemophilia A: Insights from a real-world Korean setting.

INTRODUCTION: The most notable challenge facing hemophilia A treatment is the development of inhibitors against factor VIII, resulting in increased clinical and socioeconomic burdens due to the need for expensive bypassing agents (BPAs). Although immune tolerance induction (ITI) is currently the primary approach for inhibiting and reducing the inhibitors, the lengthy duration of ITI necessitates the continued use of BPA to manage bleeding episodes. In this study, we aimed to obtain real-world evidence on the clinical and economic aspects and associated burdens experienced by patients with hemophilia A with inhibitors undergoing ITI in Korea. METHODS: Claims data from January 1, 2007, to December 31, 2020, were used in this study. The study cohort comprised patients with hemophilia A undergoing ITI, who were categorized into three groups: successful, failed, or continuation of ITI. We evaluated clinical and economic burdens, including monthly healthcare visits, medication costs, and total medical expenses. RESULTS: The study involved 33 cases of ITI across 32 patients. Excluding seven continuation cases where success could not be determined at the observation point, the estimated success rate of ITI was 80.8 %. The median duration of ITI for all patients was 25.7 months. While no significant disparities were noted in the ITI duration between successful and unsuccessful cases (24.51 vs. 25.66 months), substantial discrepancies were observed in the duration of BPA usage (11.10 vs. 25.66 months) and the number of prescribed BPAs (1.79 vs. 2.97). CONCLUSION: Successful ITI reduced both clinical and economic burdens, resulting in decreased monthly medication expenses and overall medical costs.

Recent updates on treatment patterns in patients with treated attention-deficit/hyperactivity disorders from a nationwide real-world database in South Korea.

The prevalence of attention-deficit/hyperactivity disorder (ADHD) is steadily increasing across Korea. We analyzed ADHD patients with ADHD medications (Rx) characteristics and treatment patterns compared to patients without Rx and identified the differences between pediatric-/adult- and active-/transient-patients with Rx. Using a nationwide claims dataset from 2020 to 2021, we conducted a prevalence-based cross-sectional study and analyzed the recent patients' characteristics and patterns among ADHD patients. Among 132 017 ADHD patients with Rx, differences from 20 312 without Rx across all characteristics except sex. We found significant differences in characteristics and treatment patterns between pediatric-/adult- and active-/transient-patients with Rx. Age-specific sex ratios notably diverged in pediatric patients (61.2%), but remained similar in adults, revealing significant psychiatric comorbidities differences. Active-patients peaked at 6-11 years (41.4%), while transient-patients at 18-30 years (36.1%). Predominantly, methylphenidate (89.7%), atomoxetine (27.8%), and clonidine (2.8%) were prescribed, with 85% experiencing treatment changes within methylphenidate formulations. In pediatric patients, extended-release methylphenidate was preferred (56.1%), adults favored oral delivery system methylphenidate (71.5%), and active-patients had higher treatment rates than transient-patients across all patterns, with low monotherapy rates. This study provides epidemiologic insights into recent characteristics and treatment patterns of ADHD patients with Rx in Korea, providing valuable evidence for identifying those actively receiving ADHD treatment in future healthcare policy decisions.

Development and evaluation of a post-traumatic growth promotion programme for North Korean refugees.

North Korean refugees exposed to traumatic events often experience a high recurrence of post-traumatic stress disorder symptoms. However, a post-traumatic growth programme has the potential to transform these traumatic events into increasing post-traumatic growth, reduced emotional stress and enhanced well-being. This study investigated the effects of a post-traumatic growth promotion programme on post-traumatic stress disorder recovery among North Korean refugees. Using a non-equivalent control group non-synchronised pretest-posttest design, 60 North Korean refugees who have been in South Korea for 6-8 or 12-13 years were assigned to the experimental (post-traumatic growth promotion programme; n = 30) or control group (post-traumatic growth promotion education brochure; n = 30). The programme comprised group sessions and discussions, each lasting 120 min/session, conducted twice a week for 5 weeks. Mindfulness, anxiety, depression, blood cortisol and post-traumatic growth were assessed at baseline, immediately after intervention and 4 weeks after intervention. The findings showed the programme was effective in significantly increasing post-traumatic growth and decreasing anxiety, depression and cortisol level. The two-way analysis of variance showed a significant interaction between groups and time. Consequently, this post-traumatic growth promotion programme can be utilised as a non-invasive, cost-effective and safe intervention for promoting post-traumatic growth and well-being among North Korean refugees.

Effects of the coronavirus disease outbreak on the development of neurological disorders in children: A comparison of the incidence of febrile seizure and epilepsy using an interrupted time-series approach.

BACKGROUND: With the outbreak of COVID-19, school closures and quarantines following social distancing have brought significant changes to children's lifestyles. Therefore, we aimed to compare the population-adjusted incidence of febrile seizures(FS) and epilepsy before and after the COVID-19 outbreak in Korea and to assess the effects of the COVID-19 outbreak on the incidence by region and age group. METHODS: A retrospective cohort study was conducted using nationwide claims data and covid data from January 2019 to December 2020. The incidence of diseases and difference in incidence before (Jan 20 to Dec 30, 2019) and after (Jan 20 to Dec 30, 2020) the COVID-19 outbreak was measured using rate ratio. An Interrupted time series analysis was used to identify the effect of COVID-19 on trends of FS and epilepsy. Subgroup analysis by age, sex, insurance, and risk of coronavirus by area were conducted. RESULTS: Following the onset of the pandemic, the number of newly diagnosed FS cases decreased sharply by 69 % (24,182 to 7238), whereas the incidence of epilepsy, increased to 1.02 times (30,286-29,312), when adjusted in proportion to the population. Notably, a greater decrease in the incidence of FS were found in the regions with high-risk of coronavirus. A result of segmented regression analysis proved the decrease was significant and made immediately after the pandemic started(p < 0.001). In contrast to the incidence of FS, that of epilepsy did not exhibit a significant month-to-month change during the baseline period, immediately after the pandemic started, and during the pandemic. CONCLUSIONS: The COVID-19 outbreak and resulting social distancing measures reduced the incidence of febrile seizure immediately rather than gradually. Unlike in the case of acute febrile seizure, the COVID-19 pandemic had no effect on the incidence of chronic epilepsy.

Direct Imaging of "Patch-Clasping" and Relaxation in Robust and Flexible Nanoparticle Assemblies.

Polymer patching on inorganic nanoparticles (NPs) enables multifunctionality and directed self-assembly into nonclosely packed optical and mechanical metamaterials. However, experimental demonstration of such assemblies has been scant due to challenges in leveraging patch-induced NP-NP attractions and understanding NP self-assembly dynamics. Here we use low-dose liquid-phase transmission electron microscopy to visualize the dynamic behaviors of tip-patched triangular nanoprisms upon patch-clasping, where polymer patches interpenetrate to form cohesive bonds that connect NPs. Notably, these bonds are longitudinally robust but rotationally flexible. Patch-clasping is found to allow highly selective tip-tip assembly, interconversion between dimeric bowtie and sawtooth configurations, and collective structural relaxation of NP networks. The integration of single particle tracking, polymer physics theory, and molecular dynamics simulation reveals the macromolecular origin of patch-clasping-induced NP dynamics. Our experiment-computation integration can aid the design of stimuli-responsive nanomaterials, such as topological metamaterials for chiral sensors, waveguides, and nanoantennas.

Trends in the Utilization of Herbal and Dietary Supplements in Patients with Chronic Liver Disease During the SARS-CoV2 Pandemic.

Background: We studied the pattern of herbal and dietary supplement (HDS) use in patients with chronic liver disease (CLD) during the first year of the COVID-19 pandemic. Methods: A questionnaire/survey was sent to hepatology patients with CLD under the care of hepatologists at Johns Hopkins University School of Medicine. Results: The 5 most taken dietary supplements during the pandemic included vitamin B12 (27.7%), vitamin C (32.4%), vitamin D (54.6%), zinc (25.4%) and green tea extract (20.8%). Most participants (82.3%) did not discuss their HDS use with their hepatology providers. Conclusions: Healthcare providers should be mindful of potential HDS use in patients with CLD.

Outbreak of severe diarrhea due to zoonotic Cryptosporidium parvum and C. xiaoi in goat kids in Chungcheongbuk-do, Korea.

Severe diarrhea was reported in goat kids in Chungcheongbuk-do, Korea, from 2021 to 2023, and Cryptosporidium infection was suspected. To confirm the cause of this outbreak, fecal samples were collected from goat farms where diarrhea had been reported and analyzed for Cryptosporidium infection using a molecular assay. A total of 65 fecal samples, including 37 from goats with diarrhea and 28 from goats without diarrhea, were collected from six goat farms. Forty-eight of the goats were kids (<2 months) and 17 were adults (>1 year). Cryptosporidium was identified in 53.8% (35/65) of total samples. Overall, 86.5% (32/37) of the diarrheic fecal samples tested positive; however, Cryptosporidium was not detected in any fecal sample from non-diarrheic adult goats. Therefore, cryptosporidiosis was significantly associated with diarrhea in goat kids, and adult goats were not responsible for transmission of Cryptosporidium to them. Phylogenetic analysis and molecular characterization revealed two Cryptosporidium species, namely, C. parvum (n = 28) and C. xiaoi (n = 7). In the C. parvum-positive samples, gp60 gene analysis revealed three zoonotic subtypes-IIaA18G3R1, IIdA15G1, and IIdA16G1. To the best of our knowledge, this study is the first to identify C. parvum IIaA18G3R1 and IIdA16G1 in goats, as well as the first to identify C. xiaoi in goats in Korea. These results suggest that goat kids play an important role as reservoir hosts for different Cryptosporidium species and that continuous monitoring with biosecurity measures is necessary to control cryptosporidiosis outbreaks.

Insertional biceps tendinopathy palliated successfully with intra-articular triamcinolone acetonide injection in a dog: A case report.

This report describes a dog diagnosed with insertional biceps tendinopathy that was palliated with intra-articular triamcinolone acetonide injections. The patient was a 6-year-old spayed female Chihuahua dog that had left thoracic limb lameness for 3 months before presentation. On physical examination, moderate pain was elicited by performing the biceps test and isolated full elbow extension on the left thoracic limb. Gait analysis showed asymmetrical peak vertical force and vertical impulse between thoracic limbs. Computed tomography (CT) revealed enthesophyte formation on the ulnar tuberosity of the left elbow joint. Ultrasonography showed a heterogeneous fibre pattern at the biceps tendon insertion site on the left elbow joint. These findings confirmed insertional biceps tendinopathy based on physical examination, CT and ultrasonography results. The dog received an intra-articular triamcinolone acetonide injection with hyaluronic acid in the left elbow joint. Clinical signs improved after the first injection, including a range of motion, pain and gait. A second injection was given in the same manner because of recurring mild lameness 3 months later. No clinical signs were observed during the follow-up period.

Outcomes in Patients with Pulmonary Arterial Hypertension Underwent Transcatheter Closure of an Atrial Septal Defect.

Pulmonary arterial hypertension (PAH) related to an atrial septal defect (ASD) poses a challenge to transcatheter closure of an ASD (tcASD). We aimed to determine the predictors for remaining PAH (rPAH) post-tcASD. This retrospective study was conducted at a single tertiary university hospital. Adult patients with an ASD and PAH were divided into three groups according to pulmonary vascular resistance (PVR). Normalization of pulmonary atrial systolic pressure (PASP) was defined as an estimated right ventricular systolic pressure < 40 mmHg and was determined using transthoracic echocardiography. Among 119 patients, 80% showed PAH normalization post-tcASD. Normalization of PAH post-tcASD was observed in 100%, 56.2%, and 28.6% of patients in mild, moderate, and severe PVR groups, respectively. The patients' New York Heart Association functional class improved. Multivariate logistic regression analysis showed that age and high PVR were significant risk factors for rPAH. A receiving operator curve analysis showed a PASP cutoff value > 67.5 mmHg to be predictive of rPAH post-tcASD, with an area under the curve value of 0.944 (sensitivity, 0.922; specificity 0.933). Most patients, including moderate-to-severe PAH patients, improved hemodynamically and clinically with tcASD. Since patients with severe PAH are at a risk of rPAH, tcASD should be performed by selecting the patient carefully based on pre-procedure medication, a vasoreactivity test, and a balloon occlusion test.

Visible light-curable methacrylated glycol chitosan hydrogel patches for prenatal closure of fetal myelomeningocele.

In this study, we prepared visible light-curable methacrylated glycol chitosan (MGC) hydrogel patches for the prenatal treatment of fetal myelomeningocele (MMC) and investigated their feasibility using a retinoic acid-induced fetal MMC rat model. 4, 5, and 6 w/v% of MGC were selected as candidate precursor solutions, and photo-cured for 20 s, because the resulting hydrogels were found to possess concentration dependent tunable mechanical properties and structural morphologies. Moreover, these materials exhibited no foreign body reactions with good adhesive properties in animal studies. The inflammation scoring assessment in vivo exhibited the absence of foreign body reactions in MGC hydrogel treated lesion. The complete epithelial coverage of MMC was made with using 6 w/v% MGC hydrogel followed by well-organized granulation along with noticeable decrease of abortion rate and wound size that highlight the therapeutic potential for the prenatal treatment of fetal MMC.

Unravelling crystal growth of nanoparticles.

Crystal growth from nanoscale constituents is a ubiquitous phenomenon in biology, geology and materials science. Numerous studies have focused on understanding the onset of nucleation and on producing high-quality crystals by empirically sampling constituents with different attributes and varying the growth conditions. However, the kinetics of post-nucleation growth processes, an important determinant of crystal morphology and properties, have remained underexplored due to experimental challenges associated with real-space imaging at the nanoscale. Here we report the imaging of the crystal growth of nanoparticles of different shapes using liquid-phase transmission electron microscopy, resolving both lateral and perpendicular growth of crystal layers by tracking individual nanoparticles. We observe that these nanoscale systems exhibit layer-by-layer growth, typical of atomic crystallization, as well as rough growth prevalent in colloidal systems. Surprisingly, the lateral and perpendicular growth modes can be independently controlled, resulting in two mixed crystallization modes that, until now, have received only scant attention. Combining analytical considerations with molecular dynamics and kinetic Monte Carlo simulations, we develop a comprehensive framework for our observations, which are fundamentally determined by the size and shape of the building blocks. These insights unify the understanding of crystal growth across four orders of magnitude in particle size and suggest novel pathways to crystal engineering.

Role of lower dose hepatitis B immune globulin prophylaxis in liver transplantation: A single center perspective.

Background and Aim: Prevention of hepatitis B virus (HBV) reinfection is important for long-term outcomes following liver transplantation (LT). Hepatitis B immunoglobulin (HBIG) is used among recipients who have (i) native HBV disease, (ii) hepatitis B core antibody positivity (HBcAb positivity), or (iii) received HBcAb positive organs. Nucleos(t)ide analogue (NA) monotherapy is emerging for treating patients in this setting. There is no generalized consensus on the ideal dosage of HBIG. The aim of this study was to evaluate the efficacy of low-dose HBIG (1560 international unit [IU]) for post-LT HBV prevention. Materials and Methods: HBcAb positive patients who received either HBcAb positive or hepatitis B core antibody negative (HBcAb negative) organs and HBcAb negative patients who received HBcAb positive organs between January 2016 and December 2020 were reviewed. Pre-LT HBV serologies were collected. HBV-prophylaxis strategy included NA with/without HBIG. HBV recurrence was defined as HBV deoxyribonucleic acid (DNA) positivity during the 1-year, post-LT follow-up. No HBV surface antibody titers were followed. Results: A total of 103 patients with a median age of 60 years participated in the study. Hepatitis C virus was the most common etiology. Thirty-seven HBcAb negative recipients and 11 HBcAb positive recipients with undetectable HBV DNA received HBcAb positive organs and underwent prophylaxis with 4 doses of low-dose HBIG and NA. None of the recipients in our cohort had a recurrence of HBV at 1 year. Conclusion: Low-dose HBIG (1560 IU) × 4 days and NA, for HBcAb positive recipients and HBcAb positive donors, appear to be effective in preventing HBV reinfection during the post-LT period. Further trials are needed to confirm this observation.

Outcomes of immunotherapy-related hepatotoxicity from a multi-disciplinary toxicity team.

BACKGROUND: Despite the efficacy of immune checkpoint inhibitors (ICIs), adverse events including hepatotoxicity limit their ongoing use. We investigated the outcomes and management of patients with immune-mediated hepatitis (IMH) and clinical predictors of toxicity resolution. METHODS: Patients referred to our multidisciplinary immunotherapy-related toxicity group from August 2017 to December 2020 for IMH were evaluated. Toxicity was defined according to CTCAEv4.0. IMH resolution was defined as liver enzyme normalization after steroid initiation. RESULTS: Thirty-three patients were included in the study, 62% female, and 71% Caucasian. The most common ICI used was PD-1/PD-L1 (76%). Peak IMH occurred at a median of 89 [45,193] days, for which most patients received 1-2 mg/kg/day prednisone equivalent with 35% requiring MMF. Median follow-up was 123 [33,472] days with IMH resolution seen in 48% of patients at a median of 111 [41,214] days. While high-dose steroid use was not associated with IMH resolution, liver enzyme improvement one week after steroids predicted resolution in univariate analysis (p = 0.041). All 11 patients without IMH resolution died from cancer progression or complications with three patients having acute liver failure. Available liver biopsies showed bile duct injury, with varying degrees of portal and lobular inflammation. CONCLUSION: IMH improvement one week after steroid initiation may predict ultimate IMH resolution.

Health disparity and healthcare utilization inequity among older adults living in poverty in South Korea: a cross-sectional study.

BACKGROUND: Korea has a two-tiered universal health security system: the wage-based National Health Insurance (NHI) program and government-subsidized Medical Aid (MA) program. Beneficiaries of the MA program belong to the lowest economic class. This study aims to investigate the association between economic status-defined as NHI or MA enrollment-and health disparity of older people aged ≥ 65 years in South Korea. METHODS: The claims records of 672,525 older age population from the 2017 Health Insurance Review and Assessment Service-Adult Patient Sample were used to estimate adjusted odds ratios (aORs) of MA vs. NHI beneficiaries for prevalence for common geriatric diseases. Logistic regression and negative binomial regression were used to investigate the association between economic status and prevalence or healthcare utilization for each disease. RESULTS: MA beneficiaries showed significantly higher prevalence than NHI beneficiaries for seven out of nine diseases (aORs ranging from 1.18 to 1.95). The discrepancy in the prevalence between the two groups was highest among those aged 65-69 years (aORs: 1.34-2.94), and diminished as they got older (aORs: 1.05-1.67). MA beneficiaries had significantly more outpatient visits to treat six diseases (aORs: 1.07-1.28), and more hospitalization to treat seven diseases (aORs:1.08-1.73) than NHI beneficiaries. CONCLUSION: The higher prevalence of common geriatric diseases among MA than NHI beneficiaries confirms unfavorable health disparity in the elderly living in extreme poverty. Similar or higher healthcare utilization in treating the same conditions among MA beneficiaries suggests a low possibility of inequity for access to healthcare resources covered by the universal health security system due to poor economic status. Greater excess use of inpatient than outpatient care by MA beneficiaries implies that the condition of poor older adults might be more severe when diagnosed with the same disease.

Symmetry-breaking in patch formation on triangular gold nanoparticles by asymmetric polymer grafting.

Synthesizing patchy particles with predictive control over patch size, shape, placement and number has been highly sought-after for nanoparticle assembly research, but is fraught with challenges. Here we show that polymers can be designed to selectively adsorb onto nanoparticle surfaces already partially coated by other chains to drive the formation of patchy nanoparticles with broken symmetry. In our model system of triangular gold nanoparticles and polystyrene-b-polyacrylic acid patch, single- and double-patch nanoparticles are produced at high yield. These asymmetric single-patch nanoparticles are shown to assemble into self-limited patch‒patch connected bowties exhibiting intriguing plasmonic properties. To unveil the mechanism of symmetry-breaking patch formation, we develop a theory that accurately predicts our experimental observations at all scales-from patch patterning on nanoparticles, to the size/shape of the patches, to the particle assemblies driven by patch‒patch interactions. Both the experimental strategy and theoretical prediction extend to nanoparticles of other shapes such as octahedra and bipyramids. Our work provides an approach to leverage polymer interactions with nanoscale curved surfaces for asymmetric grafting in nanomaterials engineering.

Chiral assemblies of pinwheel superlattices on substrates.

The unique topology and physics of chiral superlattices make their self-assembly from nanoparticles highly sought after yet challenging in regard to (meta)materials1-3. Here we show that tetrahedral gold nanoparticles can transform from a perovskite-like, low-density phase with corner-to-corner connections into pinwheel assemblies with corner-to-edge connections and denser packing. Whereas corner-sharing assemblies are achiral, pinwheel superlattices become strongly mirror asymmetric on solid substrates as demonstrated by chirality measures. Liquid-phase transmission electron microscopy and computational models show that van der Waals and electrostatic interactions between nanoparticles control thermodynamic equilibrium. Variable corner-to-edge connections among tetrahedra enable fine-tuning of chirality. The domains of the bilayer superlattices show strong chiroptical activity as identified by photon-induced near-field electron microscopy and finite-difference time-domain simulations. The simplicity and versatility of substrate-supported chiral superlattices facilitate the manufacture of metastructured coatings with unusual optical, mechanical and electronic characteristics.

Seeking regularity from irregularity: unveiling the synthesis-nanomorphology relationships of heterogeneous nanomaterials using unsupervised machine learning.

Nanoscale morphology of functional materials determines their chemical and physical properties. However, despite increasing use of transmission electron microscopy (TEM) to directly image nanomorphology, it remains challenging to quantify the information embedded in TEM data sets, and to use nanomorphology to link synthesis and processing conditions to properties. We develop an automated, descriptor-free analysis workflow for TEM data that utilizes convolutional neural networks and unsupervised learning to quantify and classify nanomorphology, and thereby reveal synthesis-nanomorphology relationships in three different systems. While TEM records nanomorphology readily in two-dimensional (2D) images or three-dimensional (3D) tomograms, we advance the analysis of these images by identifying and applying a universal shape fingerprint function to characterize nanomorphology. After dimensionality reduction through principal component analysis, this function then serves as the input for morphology grouping through unsupervised learning. We demonstrate the wide applicability of our workflow to both 2D and 3D TEM data sets, and to both inorganic and organic nanomaterials, including tetrahedral gold nanoparticles mixed with irregularly shaped impurities, hybrid polymer-patched gold nanoprisms, and polyamide membranes with irregular and heterogeneous 3D crumple structures. In each of these systems, unsupervised nanomorphology grouping identifies both the diversity and the similarity of the nanomaterial across different synthesis conditions, revealing how synthetic parameters guide nanomorphology development. Our work opens possibilities for enhancing synthesis of nanomaterials through artificial intelligence and for understanding and controlling complex nanomorphology, both for 2D systems and in the far less explored case of 3D structures, such as those with embedded voids or hidden interfaces.

Reversibly Controlled Ternary Polar States and Ferroelectric Bias Promoted by Boosting Square-Tensile-Strain.

Interaction between dipoles often emerges intriguing physical phenomena, such as exchange bias in the magnetic heterostructures and magnetoelectric effect in multiferroics, which lead to advances in multifunctional heterostructures. However, the defect-dipole tends to be considered the undesired to deteriorate the electronic functionality. Here, deterministic switching between the ferroelectric and the pinched states by exploiting a new substrate of cubic perovskite, BaZrO3 is reported, which boosts the square-tensile-strain to BaTiO3 and promotes four-variants in-plane spontaneous polarization with oxygen vacancy creation. First-principles calculations propose a complex of an oxygen vacancy and two Ti3+ ions coins a charge-neutral defect-dipole. Cooperative control of the defect-dipole and the spontaneous polarization reveals ternary in-plane polar states characterized by biased/pinched hysteresis loops. Furthermore, it is experimentally demonstrated that three electrically controlled polar-ordering states lead to switchable and nonvolatile dielectric states for application of nondestructive electro-dielectric memory. This discovery opens a new route to develop functional materials via manipulating defect-dipoles and offers a novel platform to advance heteroepitaxy beyond the prevalent perovskite substrates.