A dual spin-controlled chiral two-/three-dimensional perovskite artificial leaf for efficient overall photoelectrochemical water splitting.

The oxygen evolution reaction, which involves high overpotential and slow charge-transport kinetics, plays a critical role in determining the efficiency of solar-driven water splitting. The chiral-induced spin selectivity phenomenon has been utilized to reduce by-product production and hinder charge recombination. To fully exploit the spin polarization effect, we herein propose a dual spin-controlled perovskite photoelectrode. The three-dimensional (3D) perovskite serves as a light absorber while the two-dimensional (2D) chiral perovskite functions as a spin polarizer to align the spin states of charge carriers. Compared to other investigated chiral organic cations, R-/S-naphthyl ethylamine enable strong spin-orbital coupling due to strengthened π-π stacking interactions. The resulting naphthyl ethylamine-based chiral 2D/3D perovskite photoelectrodes achieved a high spin polarizability of 75%. Moreover, spin relaxation was prevented by employing a chiral spin-selective L-NiFeOOH catalyst, which enables the secondary spin alignment to promote the generation of triplet oxygen. This dual spin-controlled 2D/3D perovskite photoanode achieves a 13.17% of applied-bias photon-to-current efficiency. Here, after connecting the perovskite photocathode with L-NiFeOOH/S-naphthyl ethylamine 2D/3D photoanode in series, the resulting co-planar water-splitting device exhibited a solar-to-hydrogen efficiency of 12.55%.

Fluorinated Organic Cations Derived Chiral 2D Perovskite Enabling Enhanced Spin-Dependent Oxygen Evolution Reaction.

Chirality-induced spin selectivity observed in chiral 2D organic-inorganic hybrid perovskite holds promise to achieve spin-dependent electrochemistry. However, conventional chiral 2D perovskites suffer from low conductivity and hygroscopicity, limiting electrochemical performance and operational stability. Here, a cutting-edge material design is introduced to develop a stable and efficient chiral perovskite-based spin polarizer by employing fluorinated chiral cation. The fluorination approach effectively promotes the charge carrier transport along the out-of-plane direction by mitigating the dielectric confinement effect within the multi-quantum well-structured 2D perovskite. Integrating the fluorinated cation incorporated spin polarizer with BiVO4 photoanode considerably boosts the photocurrent density while reducing overpotential through a spin-dependent oxygen evolution reaction. Furthermore, the hydrophobic nature of fluorine in spin polarizer endows operational stability to the photoanode, extending the durability by 280% as compared to the device with non-fluorinated spin polarizer.

Core-Shell Perovskite Quantum Dots for Highly Selective Room-Temperature Spin Light-Emitting Diodes.

Circularly polarized light (CPL) is a crucial light source with a wide variety of potential applications such as magnetic recording, and 3D display. Here, core-shell heterostructured perovskite quantum dots (QDs) for room-temperature spin-polarized light-emitting diodes (spin-LEDs) are developed. Specifically, a 2D chiral perovskite shell is deposited onto the achiral 3D inorganic perovskite (CsPbBr3 ) core. Owing to the chiral-induced spin selectivity effect, the spin state of the injected charge carriers is biased when they are transmitted through the 2D chiral shell. The spin-controlled carriers then radiatively recombine inside the CsPbBr3 emissive core, resulting in CPL emission. It is demonstrated that the (R)- and (S)-1-(2-(naphthyl)ethylamine) (R-/S-NEA) 2D chiral cations enhance the spin polarization degree due to their strong chiroptical properties. Systematical defect analyses confirm that 2D chiral cations (i.e., R-/S-NEA) successfully passivate halide vacancies at the surface of the CsPbBr3 QDs, thereby attaining a high photoluminescence quantum yield of 78%. Moreover, the spin-LEDs prepared with core-shell QDs achieve a maximum external quantum efficiency of 5.47% and circularly polarized electroluminescence with a polarization degree (PCP-EL ) of 12% at room temperature. Finally, various patterns fabricated by inkjet printing the core-shell QDs emit strong CPL, highlighting their potential as an emitter for next-generation displays.

Unraveling chirality transfer mechanism by structural isomer-derived hydrogen bonding interaction in 2D chiral perovskite.

In principle, the induced chirality of hybrid perovskites results from symmetry-breaking within inorganic frameworks. However, the detailed mechanism behind the chirality transfer remains unknown due to the lack of systematic studies. Here, using the structural isomer with different functional group location, we deduce the effect of hydrogen-bonding interaction between two building blocks on the degree of chirality transfer in inorganic frameworks. The effect of asymmetric hydrogen-bonding interaction on chirality transfer was clearly demonstrated by thorough experimental analysis. Systematic studies of crystallography parameters confirm that the different asymmetric hydrogen-bonding interactions derived from different functional group location play a key role in chirality transfer phenomena and the resulting spin-related properties of chiral perovskites. The methodology to control the asymmetry of hydrogen-bonding interaction through the small structural difference of structure isomer cation can provide rational design paradigm for unprecedented spin-related properties of chiral perovskite.

Clinical Significance of Antineutrophil Cytoplasmic Antibody Positivity in Patients Infected with SARS-CoV-2.

OBJECTIVES: To investigate the rate of antineutrophil cytoplasmic antibody (ANCA) positivity and its clinical significance in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: This study included 178 patients infected with SARS-CoV-2 who were enrolled in a cohort at a single centre. Myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA levels in stored blood sera were measured using immunoassay kits. Mortality, mechanical ventilator care, and severe infection were assessed as three poor outcomes. The 2022 American College of Rheumatology and the European Alliance of Associations for Rheumatology (ACR/EULAR) classification criteria for the three subtypes of AAV were applied only to patients who had MPO-ANCA or PR3-ANCA among study subjects. RESULTS: The detection rate of ANCA positivity was 18.5%. MPO-ANCA and PR3-ANCA were found in 22 (12.4%) and 14 (7.9%) patients, respectively. However, neither MPO-ANCA nor PR3-ANCA affected the three poor outcomes. According to the new criteria, 12 (6.7%) and 21 (11.8%) patients were classified as having granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), respectively. CONCLUSIONS: SARS-CoV-2 infection may increase the rate of ANCA positivity. Although it might not affect poor outcomes, it might contribute to the classification of GPA and MPA despite uncertain clinical significance.

Universal Bifacial Stamping Approach Enabling Reverse-Graded Ruddlesden-Popper 2D Perovskite Solar Cells.

Quasi 2D perovskite solar cells (PSCs) are promising light absorbers that overcome the inherent instabilities of 3D perovskites. High-performance and stable 2D PSCs require careful control over the crystallographic orientation and phase distribution. This study introduces a simple and universal bifacial stamping method to obtain highly oriented perovskite crystals with a reverse-graded structure, where the low-n-value 2D perovskite phases are located mainly at the film surfaces. Bifacial stamping of 3D perovskite films atop the 2D films enables incorporation of 2D spacer cations into the 3D film surfaces, forming reverse-graded quasi-2D perovskite films. During stamping, suppressed evaporation of the precursor solvent induces heterogeneous nucleation from the contact interface between the 2D and 3D films, resulting in well-crystallized perovskite films having out-of-plane alignments with respect to the substrate. Thus, a highly oriented and reverse-graded quasi-2D perovskite with an average n value of 18 is obtained with power conversion efficiency exceeding 17% and high open-circuit voltage of 1.11 V for iso-butylammonium (iso-BA)-based (iso-BA2 MAn -1 Pbn I3 n +1 ) PSCs. The unencapsulated device retains 92% of its initial efficiency after aging at 40 ± 5% relative humidity for 1200 h. This work provides a new strategy for fabricating highly oriented and phase-controlled quasi-2D PSCs.

An Outbreak of KPC-Producing Klebsiella pneumoniae Linked with an Index Case of Community-Acquired KPC-Producing Isolate: Epidemiological Investigation and Whole Genome Sequencing Analysis.

Aims: A hospital outbreak of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPN) linked with an index case of community-acquired infection occurred in an urban tertiary care hospital in Seoul, South Korea. Therefore, we performed an outbreak investigation and whole genome sequencing (WGS) analysis to trace the outbreak and investigate the molecular characteristics of the isolates. Results: From October 2014 to January 2015, we identified a cluster of three patients in the neurosurgery ward with sputum cultures positive for carbapenem-resistant KPN. An epidemiological investigation, including pulsed-field gel electrophoresis analysis was performed to trace the origins of this outbreak. The index patient's infection was community acquired. Active surveillance cultures using perirectal swabbing from exposed patients, identified one additional patient with KPC-producing KPN colonization. WGS analyses using PacBio RSII instruments were performed for four linked isolates. WGS revealed a genetic linkage of the four isolates belonging to the same sequence type (ST307). All KPN isolates harbored conjugative resistance plasmids, which has blaKPC-2 carbapenemase genes contained within the Tn4401 "a" isoform and other resistance genes. However, WGS showed only three isolates among four KPC-producing KPN were originated from a common origin. Conclusions: This report demonstrates the challenge that KPC-2-producing KPN with the conjugative resistance plasmid may spread not only in hospitals but also in community, and WGS can help to accurately characterize the outbreak.

Changes in the utilization patterns of antifungal agents, medical cost and clinical outcomes of candidemia from the health-care benefit expansion to include newer antifungal agents.

OBJECTIVES: In 2014, South Korea expanded its national health insurance coverage to include newer antifungal agents, such as echinocandins. This study aimed to investigate the effects of policy change on the prescription patterns of antifungals, medical costs and clinical outcomes of candidemia. METHODS: This retrospective cohort enrolled hospitalized patients with candidemia at three tertiary care hospitals in South Korea from January 2012 to December 2015. The utilization of antifungal agents, medical costs, length of hospital stay (LOS), and mortality before and after the health-care benefit expansion were compared, and the factors associated with all-cause 28-day mortality during the study period were analyzed. RESULTS: A total of 769 candidemia cases were identified. The incidence of candidemia did not significantly vary during the study period (P = 0.253). The proportion of echinocandins, as the initial antifungal agent, and medical costs associated with candidemia significantly increased since the change in insurance coverage (P < 0.001). There was no significant difference in LOS and mortality associated with candidemia before and after the health-care benefit expansion (P = 0.696 and 0.931, respectively). Multivariate logistic regression analysis showed that initial treatment with caspofungin was associated with decreased mortality (adjusted odds ratio: 0.784; 95% confidence interval: 0.681-0.902; reference: fluconazole). CONCLUSIONS: Although the utilization of newer antifungal agents and medical cost for candidemia has significantly increased since the health-care benefit expansion, there has been no change in the outcome of candidemia. However, the further increased use of newer antifungals may improve the outcome of candidemia in this country.

Integrase Strand Transfer Inhibitor Resistance Mutations in Antiretroviral Therapy-Naive and Treatment-Experienced HIV Patients in South Korea.

Updated guidelines for the treatment of antiretroviral therapy (ART)-negative patients with HIV recommend integrase strand transfer inhibitor (INSTI)-based regimens. HIV patients are tested for resistance to antiretrovirals, and the reported prevalence of transmitted INSTI resistance remains rare worldwide. However, no data related to INSTI resistance in Korean HIV patients have been reported. We aimed to determine the prevalence of INSTI resistance-related mutations in South Korea. We subjected both ART-naive (n = 58) and ART-experienced Korean HIV patients (n = 41) to genotypic resistance analysis and determined a prevalence of INSTI major resistance mutations of 3.4% (n = 2) among ART-naive patients and 22.0% (n = 9) among ART-experienced patients. In the former group, both major INSTI resistance cases involved the nonpolymorphic E92Q mutation in the integrase strand. Our findings suggest that INSTI resistance testing should be included in the standard resistance screening protocols for Korean HIV patients.

Pregnancy Rates and Outcomes of HIV-Infected Women in Korea.

BACKGROUND: Antepartum, intrapartum, and postpartum preventive measures with antiretroviral drugs, appropriate delivery methods, and discouraging breastfeeding significantly decrease the risk of mother-to-child transmission of human immunodeficiency virus (HIV) infection. Herein, we investigated the pregnancy outcomes in HIV-infected Korean women. METHODS: We retrospectively reviewed medical records of childbearing-age HIV-infected women between January 2005 and June 2017 at four tertiary care hospitals in Korea. RESULTS: Among a total of 95 HIV infected women of child-bearing age with 587.61 years of follow-up duration, 15 HIV-infected women experienced 21 pregnancies and delivered 16 infants. The pregnancy rate was 3.57 per 100 patient-years. Among the 21 pregnancies, five ended with an induced abortion, and 16 with childbirth including two preterm deliveries at 24 and 35 weeks of gestation, respectively. The two preterm infants had low birth weight and one of them died 10 days after delivery due to respiratory failure. Among the 14 full-term infants, one infant was small for gestational age. There were no HIV-infected infants. CONCLUSION: The pregnancy rate of HIV-infected women in Korea is lower than that of the general population. Although several adverse pregnancy outcomes were observed, mother-to-child transmission of HIV infection was successfully prevented with effective preventive measures.

Antibiotic-Related Adverse Drug Reactions at a Tertiary Care Hospital in South Korea.

BACKGROUND: Adverse drug reactions (ADRs) are any unwanted/uncomfortable effects from medication resulting in physical, mental, and functional injuries. Antibiotics account for up to 40.9% of ADRs and are associated with several serious outcomes. However, few reports on ADRs have evaluated only antimicrobial agents. In this study, we investigated antibiotic-related ADRs at a tertiary care hospital in South Korea. METHODS: This is a retrospective cohort study that evaluated ADRs to antibiotics that were reported at a 2400-bed tertiary care hospital in 2015. ADRs reported by physicians, pharmacists, and nurses were reviewed. Clinical information reported ADRs, type of antibiotic, causality assessment, and complications were evaluated. RESULTS: 1,277 (62.8%) patients were considered antibiotic-related ADRs based on the World Health Organization-Uppsala Monitoring Center criteria (certain, 2.2%; probable, 35.7%; and possible, 62.1%). Totally, 44 (3.4%) patients experienced serious ADRs. Penicillin and quinolones were the most common drugs reported to induce ADRs (both 16.0%), followed by third-generation cephalosporins (14.9%). The most frequently experienced side effects were skin manifestations (45.1%) followed by gastrointestinal disorders (32.6%). CONCLUSION: Penicillin and quinolones are the most common causative antibiotics for ADRs and skin manifestations were the most frequently experienced symptom.