bluuebunny/crossref_metadata_2025 huggingface dataset:
Intercalation of Organic Dye Molecules into Double‐stranded DNA. Part 2: The Annelated Quinolizinium Ion as a Structural Motif in DNA Intercalators†
Authors: Ihmels Heiko , Faulhaber Katja , Vedaldi Daniela , Dall'Acqua Francesco , Viola Giampietro
Published: June 2005

DNA intercalators represent an important class of compounds with a high potential as DNA‐targeting drugs. In this review it is demonstrated that annelated quinolizinium derivatives such as coralyne and derivatives thereof intercalate into DNA and that this structural motif allows several variations of the substitution pattern without loss of intercalating properties. The commonly applied methods for the evaluation of the DNA association, mainly spectroscopic studies, are pointed out. In addition, studies on the biological activities of annelated quinolizinium derivatives, such as topoisomerase poisoning or cell toxicity, are highlighted.
Photobleaching of Bacteriorhodopsin Solubilized with Triton X‐100
Authors: Sasaki Takanori , Sonoyama Masashi , Demura Makoto , Mitaku Shigeki
Published: June 2005

In the current studies, we examined the effects of hexagonal lattice formation with lipid membranes on the structural stability of native bacteriorhodopsin (bR). Denaturation kinetic measurements for bR solubilized with the mild nonionic detergent Triton X‐100 (TX100) were performed in the dark and under illumination by visible light. The solubilized bR was stable in the dark over a wide concentration range of TX100 (1 to 200 mM). In purple membranes, a bilobed band was observed in visible circular dichroism spectra due to interactions between neighboring chromophores. At all concentrations of TX100, this was replaced by a single positive band. Upon illumination with visible light, TX100‐solubilized bR clearly showed photobleaching to bacterioopsin. These experimental results suggest that photobleaching is due to a lack of intermolecular interactions inside the purple membrane lattice. Extensive kinetic measurements further revealed that the rate constant of photobleaching is strongly dependent on the detergent concentration, although the activation energy for photobleaching does not significantly change with the TX100 concentration. The mechanism of photobleaching for the solubilized bR is discussed with respect to detergent micelle properties.
Outcome of mTHPC Mediated Photodynamic Therapy is Primarily Determined by the Vascular Response
Authors: Triesscheijn Martijn , Ruevekamp Marjan , Aalders Maurice , Baas Paul , Stewart Fiona A.
Published: June 2005

We have previously shown that the efficacy of photodynamic therapy (PDT) using the photosensitizer meso‐tetra‐hydrox‐yphenyl‐chlorin (mTHPC) correlated with plasma drug levels at the time of illumination rather than drug levels in human tumor xenografts or mouse skin. These results suggested that vascular‐mediated effects could be important determinants of PDT response in vivo. In the present study we further investigated the relationship between PDT response, mTHPC pharmacokinetics and the localization and extent of vascular damage induced in human squamous cell carcinoma xenografts (HNXOE). Plasma levels of mTHPC decreased exponentially with time after injection, whereas tumor drug levels remained maximal for at least 48 h. At 3 h after administration mTHPC was localized in the blood vessels, whereas at later times it was distributed throughout the whole tumor. Illumination at 3 h after mTHPC, which resulted in 100% long‐term tumor cure, led to a marked reduction of vascular perfusion and increased tumor hypoxia at 1 h after treatment. Illumination at 48 h resulted in rapid regrowth of most tumors and only 10% cure. This protocol did not affect a significant decrease in vascular perfusion or increase in tumor hypoxia. These data show that optimal responses to mTHPC‐mediated PDT were primarily dependent on the early vascular response, and that plasma drug levels at the time of illumination could predict this relationship.
Choice of Optimal Wavelength for PDT: The Significance of Oxygen Depletion
Authors: Nielsen Kristian P. , Juzeniene Asta , Juzenas Petras , Stamnes Knut , Stamnes Jakob J. , Moan Johan
Published: June 2005

We have investigated the role of tissue oxygenation on light penetration into tissue at different wavelengths. As a field of application we have chosen aminolevulinic acid–photodynamic therapy (ALA‐PDT). To calculate efficiency spectra of PDT on human skin one needs to know the excitation spectrum of the photosensitizer of interest and the relative fluence rate as a function of depth in the tissue. We measured the former and computed the latter with an accurate radiative transfer algorithm. In this way we determined the efficiency spectra as functions of depth for different types of basal cell carcinomas (BCC). Our results suggest that ALA‐PDT works best for nodular BCC at a wavelength of 630 nm, whereas it works best for pigmented superficial BCC at a wavelength of 390 nm. At 630 nm the light penetration into a tumor depends strongly on the oxygenation of the blood. Below a 2 mm thick, well‐oxygenated, nodular BCC, we find the efficiency to be an order of magnitude larger than below a poorly oxygenated tumor. At 390 nm, the light penetration into a tumor does not depend on the oxygenation of the blood.
Decrease in Langerhans Cells and Increase in Lymph Node Dendritic Cells Following Chronic Exposure of Mice to Suberythemal Doses of Solar Simulated Radiation
Authors: McLoone Pauline , Woods Gregory M. , Norval Mary
Published: June 2005

Exposure of certain strains of mice to ultraviolet radiation (UVR) causes suppression of some innate and adaptive immune responses. One such consequence of acute UVB exposure is a reduction in the number of Langerhans cells (LC) in the epidermis and an increase in dendritic cells (DC) in lymph nodes draining the irradiated skin sites. Exposure to chronic UVB irradiation also has effects on the immune system, but it is unknown what effects are caused by repeated doses of solar simulated radiation (SSR). Consequently, the main aims of the present study were to determine whether repeated exposure to low doses of SSR would lead to similar changes in these cell populations and whether chronic doses of SSR activate a protective photoadaptation mechanism. Groups of C3H/HeN mice were irradiated daily with 3.7 J/cm2 SSR from Cleo Natural lamps for 2, 10, 20, 30 or 60 days. Further groups of mice received an additional dose of 7.4 J/cm2 SSR on days 2, 10, 30 or 60 to test for photoadaptation. The numbers of LC in the epidermis and DC in the lymph nodes draining irradiated skin sites were counted 24 h after the final irradiation. With the exception of mice irradiated for only 2 days, LC were significantly reduced throughout the chronic irradiation protocol, and no recovery occurred. DC numbers were significantly increased in the draining lymph nodes of mice irradiated for 20 days and 60 days.
Retracted: Epigallocatechin‐3‐Gallate Inhibits Photocarcinogenesis Through Inhibition of Angiogenic Factors and Activation of CD8+ T Cells in Tumors
Authors: Mantena Sudheer K. , Roy Anshu M. , Katiyar Santosh K.
Published: June 2005

There has been considerable interest in the use of botanical supplements to protect skin from the adverse effects of solar UV radiation, including photocarcinogenesis. We and others have shown that topical application of (−)‐epigallocatechin‐3‐gallate (EGCG) from green tea prevents photocarcinogenesis in mice; however, the chemopreventive mechanism of EGCG in an in vivo tumor model is not clearly understood. In this study, UV‐B‐induced skin tumors with and without treatment of EGCG (∼1 mg/cm2) and age‐matched skin biopsies from SKH‐1 hairless mice were used to identify potential molecular targets of skin cancer prevention by EGCG. These biopsies were analyzed for various biomarkers of angiogenesis and antitumor immune response using immunostaining, Western blotting and gelatinolytic zymography. We report that compared to non‐EGCG‐treated tumors, topical application of EGCG in UV‐induced tumors resulted in inhibition of protein expression and activity of matrix metalloproteinase (MMP)‐2 and MMP‐9, which play crucial roles in tumor growth and metastasis. In contrast, tissue inhibitor of MMP‐1 (TIMP‐1), which inhibits MMP activity, was increased in tumors. With respect to the tumor vasculature, EGCG decreased the expression of CD31, a cell surface marker of vascular endothelial cells, and inhibited the expression of vascular endothelial growth factor in tumors, which are essential for angiogenesis. EGCG inhibited proliferating cell nuclear antigen in UV‐B‐induced tumors as well. Additionally, higher numbers of cytotoxic T lymphocytes (CD8+ T cells) were detected in EGCG‐treated tumors compared with non‐EGCG‐treated tumors. Together, these in vivo tumor data suggested that inhibition of photocarcinogenesis in mice by EGCG is associated with inhibition of angiogenic factors and induction of antitumor immune reactivity.
Thunderstorm Asthma and Climate Change
Authors: Beggs Paul J.
Published: February 2024

This JAMA Insights in the Climate Change and Health Series defines thunderstorm asthma, describes its effects and increased rate of occurrence, and highlights recommendations for improved response during future events.
Health Care AI and Patient Privacy—Dinerstein v Google
Authors: Duffourc Mindy Nunez , Gerke Sara
Published: February 2024

This Viewpoint summarizes a recent lawsuit alleging that a hospital violated patients’ privacy by sharing electronic health record (EHR) data with Google for development of medical artificial intelligence (AI) and discusses how the federal court’s decision in the case provides key insights for hospitals planning to share EHR data with for-profit companies developing medical AI.
Trends in Integration Between Physician Organizations and Pharmacies for Self-Administered Drugs
Authors: Kakani Pragya , Cutler David M. , Rosenthal Meredith B. , Keating Nancy L.
Published: February 2024

Importance

Increasing integration across medical services may have important implications for health care quality and spending. One major but poorly understood dimension of integration is between physician organizations and pharmacies for self-administered drugs or in-house pharmacies.

Objective

To describe trends in the use of in-house pharmacies, associated physician organization characteristics, and associated drug prices.

Design, Setting, and Participants

A cross-sectional study was conducted from calendar years 2011 to 2019. Participants included 20% of beneficiaries enrolled in fee-for-service Medicare Parts A, B, and D. Data analysis was performed from September 15, 2020, to December 20, 2023.

Exposures

Prescriptions filled by in-house pharmacies.

Main Outcomes and Measures

The share of Medicare Part D spending filled by in-house pharmacies by drug class, costliness, and specialty was evaluated. Growth in the number of physician organizations and physicians in organizations with in-house pharmacies was measured in 5 specialties: medical oncology, urology, infectious disease, gastroenterology, and rheumatology. Characteristics of physician organizations with in-house pharmacies and drug prices at in-house vs other pharmacies are described.

Results

Among 8 020 652 patients (median age, 72 [IQR, 66-81] years; 4 570 114 [57.0%] women), there was substantial growth in the share of Medicare Part D spending on high-cost drugs filled at in-house pharmacies from 2011 to 2019, including oral anticancer treatments (from 10% to 34%), antivirals (from 12% to 20%), and immunosuppressants (from 2% to 9%). By 2019, 63% of medical oncologists, 20% of urologists, 29% of infectious disease specialists, 21% of gastroenterologists, and 22% of rheumatologists were in organizations with specialty-relevant in-house pharmacies. Larger organizations had a greater likelihood of having an in-house pharmacy (0.75 percentage point increase [95% CI, 0.56-0.94] per each additional physician), as did organizations owning hospitals enrolled in the 340B Drug Discount Program (10.91 percentage point increased likelihood [95% CI, 6.33-15.48]). Point-of-sale prices for high-cost drugs were 1.76% [95% CI, 1.66%-1.87%] lower at in-house vs other pharmacies.

Conclusions and Relevance

In this cross-sectional study of physician organization–operated pharmacies, in-house pharmacies were increasingly used from 2011 to 2019, especially for high-cost drugs, potentially associated with organizations’ financial incentives. In-house pharmacies offered high-cost drugs at lower prices, in contrast to findings of integration in other contexts, but their growth highlights a need to understand implications for patient care.
Transgender Patient Preferences When Discussing Gender in Health Care Settings
Authors: Harner Vern , Moore Megan , Casillas Boi , Chrivoli Jess , Lopez Olivares Amaranta , Harrop Erin
Published: February 2024

Importance

Transgender (trans) patients report frequent discriminatory and harmful experiences in health care settings; gender-affirming, competent health care improves trans individuals’ health and well-being.

Objective

To identify factors influencing trans patients’ decision-making regarding sharing gender-related information with providers (clinicians, health care organizations, health care systems) and trans patient preferences for gender-related questions, as well as the subsequent impact on health care experiences.

Design, Setting, and Participants

A qualitative, interpretivist phenomenological study was conducted via telephone or video (using Zoom) in English and Spanish from August 10 to September 11, 2020. Participants were recruited via trans-specific social media groups and email listservs. Interviews were transcribed verbatim and analyzed from October 2020 to January 2022 using thematic analysis by a majority trans research team.

Main Outcomes and Measures

Semistructured interviews explored patient health care experiences and preferences.

Results

Participants included 27 trans and/or nonbinary adults (mean [SD] age, 30.9 [10.4] years; range, 21-69 years) from 13 US states. Four themes were identified: (1) impact of provider behaviors, (2) engaging in relational risk assessment, (3) receiving affirming vs medically competent care, and (4) “how are you going to fit [me] into your system?” The first theme reflected the impact of provider actions, including level of flexibility in care and interpersonal interactions, ability to explain medical relevance of gender-related questions, and preparedness to work with trans patients. Second, respondents weighed a variety of implicit or explicit safety cues when deciding whether and how to share information with providers. Third, participants spoke at length about affirming and medically competent care, noting that they have had to prioritize one over the other. Last, participants reported their needs often being at odds with health care system norms and standards of care.

Conclusion and Relevance

In this qualitative study of trans patient preferences when discussing gender-related information with providers, it was found that equitable, gender-affirming, and competent health care requires flexibility and responsiveness to patient preferences. It requires provider humility and engagement, as well as institutional policies that support competent and gender-affirming spaces. Future research could identify additional roles that providers, administrators, and systems can play in ensuring competent care for trans patients.
Sequence of Epinephrine and Advanced Airway Placement After Out-of-Hospital Cardiac Arrest
Authors: Okubo Masashi , Komukai Sho , Izawa Junichi , Kiyohara Kosuke , Matsuyama Tasuku , Iwami Taku , Kitamura Tetsuhisa
Published: February 2024

Importance

While epinephrine and advanced airway management (AAM) (supraglottic airway insertion and endotracheal intubation) are commonly used for out-of-hospital cardiac arrest (OHCA), the optimal sequence of these interventions remains unclear.

Objective

To evaluate the association of the sequence of epinephrine administration and AAM with patient outcomes after OHCA.

Design, Setting, and Participants

This cohort study analyzed the nationwide, population-based OHCA registry in Japan and included adults (aged ≥18 years) with OHCA for whom emergency medical services personnel administered epinephrine and/or placed an advanced airway between January 1, 2014, and December 31, 2019. The data analysis was performed between October 1, 2022, and May 12, 2023.

Exposure

The sequence of intravenous epinephrine administration and AAM.

Main Outcomes and Measures

The primary outcome was 1-month survival. Secondary outcomes were 1-month survival with favorable functional status and prehospital return of spontaneous circulation. To control imbalances in measured patient demographics, cardiac arrest characteristics, and bystander and prehospital interventions, propensity scores and inverse probability of treatment weighting (IPTW) were performed for shockable and nonshockable initial rhythm subcohorts.

Results

Of 259 237 eligible patients (median [IQR] age, 79 [69-86] years), 152 289 (58.7%) were male. A total of 21 592 patients (8.3%) had an initial shockable rhythm, and 237 645 (91.7%) had an initial nonshockable rhythm. Using IPTW, all covariates between the epinephrine-first and AAM-first groups were well balanced, with all standardized mean differences less than 0.100. After IPTW, the epinephrine-first group had a higher likelihood of 1-month survival for both shockable (odds ratio [OR], 1.19; 95% CI, 1.09-1.30) and nonshockable (OR, 1.28; 95% CI, 1.19-1.37) rhythms compared with the AAM-first group. For the secondary outcomes, the epinephrine-first group experienced an increased likelihood of favorable functional status and prehospital return of spontaneous circulation for both shockable and nonshockable rhythms compared with the AAM-first group.

Conclusions and Relevance

These findings suggest that for patients with OHCA, administration of epinephrine before placement of an advanced airway may be the optimal treatment sequence for improved patient outcomes.
Deep learning segmentation of organs‐at‐risk with integration into clinical workflow for pediatric brain radiotherapy
Authors: Mekki Lina , Acharya Sahaja , Ladra Matthew , Lee Junghoon
Published: February 2024

Purpose

Radiation therapy (RT) of pediatric brain cancer is known to be associated with long‐term neurocognitive deficits. Although target and organs‐at‐risk (OARs) are contoured as part of treatment planning, other structures linked to cognitive functions are often not included. This paper introduces a novel automatic segmentation tool specifically designed for the unique challenges posed by pediatric patients undergoing brain RT, as well as its seamless integration into the existing clinical workflow.

Methods and Materials

Images of 47 pediatric brain cancer patients aged 1 to 20 years old and 33 two‐year‐old healthy infants were used to train a vision transformer, UNesT, for the segmentation of five brain OARs. The trained model was then incorporated to clinical workflow via DICOM connections between a treatment planning system (TPS) and a server hosting the trained model such that scans are sent from TPS to the server, automatically segmented, and sent back to TPS for treatment planning.

Results

The proposed automatic segmentation framework achieved a median dice similarity coefficient of 0.928 (frontal white matter), 0.908 (corpus callosum), 0.933 (hippocampi), 0.819 (temporal lobes), and 0.960 (brainstem) with a mean ± SD run time of 1.8 ± 0.67 s over 20 test cases.

Conclusions

The pediatric brain segmentation tool showed promising performance on five OARs linked to neurocognitive functions and can easily be extended for additional structures. The proposed integration to the clinic enables easy access to the tool from clinical platforms and minimizes disruption to existing workflow while maximizing its benefits.
Semiconductive Biomaterials for Pathological Bone Repair and Regeneration
Authors: Fan Youzhun , Ran Heying , Wang Zhengao , Ning Chengyun , Zhai Jinxia , Yu Peng
Published: February 2024

Bone implant biomaterials are among the most used materials for clinical application. Despite significant advances in biocompatibility and osteoconductivity, conventional biomaterials lack the ability to cope with the pathological microenvironment (inflammation, infection, residual tumors, etc.) during bone repair. Semiconductor implant materials have unique electrical, optical, ultrasound, and thermal response properties, which facilitate non‐invasively and controllably dynamic repair of pathological bone defects. In this review, the design and synthesis of a new generation of semiconductor‐driven bone implant materials are summarized, the mechanism of action of semiconductive biomaterials' functional interfaces and the dynamic repair process of bone tissues are discussed, and new strategies for the problems encountered during clinical osseointegration is provided. Finally, the review outlooks the future of functional semiconductive implants for bone defect repair.
A New N‐Type High Entropy Semiconductor AgBiPbSe2S with High Thermoelectric and Mechanical Properties
Authors: Wei Yingchao , Ma Zheng , Li Wang , Li Chengjun , Yang Boyu , Sun Chengwei , Gang Shuangfu , Zhang Wenguang , Long Hui , Li Xin , Jiang Qinghui , Zhang Dan , Luo Yubo , Yang Junyou
Published: February 2024

Exploring N‐type High‐entropy materials with both high thermoelectric and mechanical properties is highly desirable for all‐high‐entropy thermoelectric generators (TEGs) since the thermoelectric and mechanical properties of N‐type one are largely behind its P‐type counterparts. Herein, a new rock‐salt structure N‐type high entropy thermoelectric AgBiPbSe2S is introduced with a bandgap of ≈0.43 eV. The atomic radii difference of each component results in a large lattice distortion of 0.246, leading to a low thermal conductivity of 0.36 W m−1 K−1 at 823 K. The figure of merit (ZT) reaches 0.6 for AgBiPbSe2S at 823 K. Moreover, Ag2Se precipitates are included in AgBiPbSe2S to filter low energy carriers for high Seebeck coefficients and to scatter phonons with nanoscale wavelength for ultralow lattice thermal conductivities. Consequently, a peak ZT of ≈1.18 at 823 K and an average ZT of 0.60 at 400–823 K are obtained for Ag1.02BiPbSe2S. More importantly, high mechanical properties are also obtained in Ag1.02BiPbSe2S, of which the Vickers hardness and flexural strength are ≈209 Hv and 32 MPa, respectively, originating from the enhanced lattice friction by chemical short‐range disorder (i.e., high entropy effect) and dispersion strengthening caused by Ag2Se nanoprecipitates.
Interface Chemical Bond Enhanced Ions Intercalated Carbon Nitride/CdSe‐Diethylenetriamine S‐Scheme Heterojunction for Photocatalytic H2O2 Synthesis in Pure Water
Authors: He Houwei , Wang Zhongliao , Zhang Jinfeng , Shao Chunfeng , Dai Kai , Fan Ke
Published: February 2024

Photosynthesis of hydrogen peroxide (H2O2) is regarded as an economically efficient and environmentally friendly synthesis method. However, the scalability of photocatalytic H2O2 production (PHP) is hindered by the sluggish reaction kinetics and rapid recombination of photogenerated charge carriers. In this study, an organic amine‐constrained ions intercalated carbon nitride/CdSe‐diethylenetriamine (K+/I−‐CN/CdSe‐D) S‐scheme heterojunction is synthesized using an organic–inorganic hybrid approach and employed for PHP for the first time. The optimization of the heterojunction interface by I− and K+ ions contributed to enhanced light absorption capabilities and reduced interlayer charge transfer distance. Concurrently, the synergy of C─Se bonds at interface effectively modulated the electron transfer pathways. The coordination environment and charge transfer mechanism are thoroughly investigated by extended X‐ray absorption fine structure and in situ irradiated X‐ray photoelectron spectroscopy. The H2O2 production rate of 40%K+/I−‐CN/CdSe‐D reached 2240.23 µmol h−1 g−1 in pure water. This study highlights the significance of dual tuning of interface chemical bonds and ionic intercalation as an effective strategy for enhancing the photocatalytic H2O2 , paving the way for further advancements in PHP technology.
Decoupling the Kinetic Essence of Iron‐Based Anodes through Anionic Modulation for Rational Potassium‐Ion Battery Design
Authors: Ma Meng , Yao Kai , Wang Yikun , Fattakhova‐Rohlfing Dina , Chong Shaokun
Published: February 2024

Potassium‐ion batteries (PIBs) have favorable characteristics in terms of cell voltage and cost efficiency, making them a promising technology for grid‐scale energy storage. The rational design of suitable electrode materials on a theoretical basis, aiming at high power and energy density, is of paramount importance to bring this battery technology to the practical market. In this paper, a series of iron‐based compounds with different non‐metal anions are selectively synthesized to investigate the nature of kinetic differences induced by anionic modulation. A combination of experimental characterization and theoretical calculation reveals that iron phosphide, with its moderate adsorption energy (Ea) and lowest diffusion barrier (Eb), exhibits the best cycling and rate properties at low electrochemical polarization, which is related to the narrow Δd‐p band center gap that facilitates ion transfer. In addition, the optimization of the electrolyte formula results in the carbon‐supported iron phosphide anode running stably over 2000 cycles at 0.5 A g−1 and exhibiting a high rate capacity of 81.1 mAh g−1 at 2 A g−1. The superior electrochemical properties are attributed to the robust KF‐rich solid electrolyte interphase formed by the highly compatible KFSI in ethylene carbonate (EC)/diethyl carbonate (DEC) configuration.
Homeostatic Solid Solution Reaction in Phosphate Cathode: Breaking High‐Voltage Barrier to Achieve High Energy Density and Long Life of Sodium‐Ion Batteries
Authors: Gu Zhen‐Yi , Zhao Xin‐Xin , Li Kai , Cao Jun‐Ming , Wang Xiao‐Tong , Guo Jin‐Zhi , Liu Han‐Hao , Zheng Shuo‐Hang , Liu Dai‐Huo , Wu Hong‐Yue , Wu Xing‐Long
Published: February 2024

The stable phase transformation during electrochemical progress drives extensive research on vanadium‐based polyanions in sodium‐ion batteries (SIBs), especially Na3V2(PO4)3 (NVP). And the electron transfer between V3+/4+ redox couple in NVP could be generally achieved, owing to the confined crystal variation during battery service. However, the more favorable V4+/5+ redox couple is still in hard‐to‐access situation due to the high barrier and further brings about the corresponding inefficiency in energy densities. In this work, the multilevel redox in NVP frame (MLNP) alters reaction pathway to undergo homeostatic solid solution process and breaks the high barrier of V4+/5+ at high voltage, taking by progressive transition metal (V, Fe, Ti, and Cr) redox couple. The diversified reaction paths across diffusion barriers could be realized by distinctive release/uptake of inactive Na1 site, confirmed by the calculations of density functional theory. Thereby its volume change is merely 1.73% during the multielectron‐transfer process (≈2.77 electrons). MLNP cathode could achieve an impressive energy density of 440 Wh kg−1, driving the leading development of MLNP among other NASICON structure SIBs. The integration of multiple redox couples with low strain modulates the reaction pathway effectively and will open a new avenue for fabricating high‐performance cathodes in SIBs.
Movable Typography Inspired Tunable Meta‐Cylinder for Multi‐Directional Microwave Beam Shaping
Authors: Zhang Meng , Yao Shupei , Zhu Bifeng , Lin Jiahan , Tao Jifang , Shang Wenli , Zhang Wu
Published: February 2024

In this paper, a multi‐directional microwave beam shaping function through a tunable meta‐cylinder inspired by the movable typography technology is demonstrated. The meta‐cylinder is constructed with stacked identical octagonal layers. On each side wall of the octagonal layer, a 1D metasurface row is patterned. The metasurface rows on different side walls are designed to reflect microwave at different phase delays. As a result, each facet of the meta‐cylinder can be arranged into different metasurface row combinations and reflect a microwave into different beam shapes when rotating the stacked octagonal layers to different states. In addition, the rotation causes the same phase delay distribution change in all meta‐cylinder facets at the same time, therefore the meta‐cylinder can manipulate the microwave from different directions in the same way simultaneously. Based on this approach, a multi‐directional beam focusing function with tunable focal length is experimentally demonstrated. The dynamical beaming shaping of the microwave in multi‐direction will have high application potential in wireless communication and microwave signal transmission and omnidirectional antennas.
Grain yield and its contributing traits in promising sweetcorn hybrids
Authors: Shahrokhi Mohsen , Khorasani Saeed Khavari , Ortez Osler
Published: February 2024

The augmentation of domestic sweetcorn (Zea mays L. saccharata) production in semiarid regions necessitates the development of new superior hybrids with high yield potential. This study aimed to identify the most influential characteristics contributing to sweetcorn grain yield in these regions. Nineteen promising sweetcorn hybrids and the commercial hybrid KSC403su as the control were examined using a randomized complete block design with three replications in a 2‐year study (2021–2022) at the Khorasan Razavi Agricultural and Natural Resources Research and Education Institute Center (ARREO) in Mashhad, Iran. The combined analysis of variance revealed significant variances attributed to genotype (G) for all studied traits, while year (Y) and G × Y effects were significant for most characteristics. Phenotypic correlations indicated a highly significant association of grain yield with grain depth (r = 0.79, p < 0.01), kernel number per row (r = 0.75, p < 0.01), row number per ear (r = 0.63, p < 0.01), ear length (r = 0.58, p < 0.01), and ear diameter (r = 0.57, p < 0.01) traits. Path analysis results emphasized the critical role of traits such as grain depth, row number per ear, and ear length, showcasing a highly significant positive direct impact on grain yield and also a significantly positive association with grain yield. In this study, hybrids PSM3, PSM4, PSM9, PSM16, and PSM19 exhibited the highest values for grain yield and yield‐contributing traits, suggesting their potential for further research in multiple locations with varying environmental conditions before being recommended to farmers.
Amine Catalyzed Remote [4+2]‐annulation Of Indole Tethered Enal And Oxindole Olefin To Access Optically Pure Hydrocarbazole Spirooxindole Scaffolds
Authors: Prasad Madavi S. , Ramesh M. , Kumar Jha Aman , Bharani Sankar , Saha Souvik , Bedanta Thoudam , Chandrasekhar Ponnada , Sarasija M.
Published: February 2024

This research showcases a methodology for crafting highly intricate hydrocarbazole spirooxindole frameworks endowed with three consecutive stereocenters. Achieved through a trienamine‐catalyzed remote [4+2]‐annulation reaction, the method's significance is underscored by synthesizing an extensive array of library molecules (up to 27 examples). These compounds mimic natural products, exhibit good yields (up to 85 %), exceptional diastereo‐, enantiomeric ratios (up to 17 : 1 dr, 99.9 : 0.1 er). The practicality of our strategy is further exemplified by successfully synthesizing a hexahydroepoxyethanocarbazole spirooxindole scaffold via a sequential [4+2]‐annulation/‐reduction/epoxidation‐cyclization reaction, achieving a 75 % overall yield, maintaining an excellent stereoselectivity (99.5 : 0.5 er).
The Role of Phase Mixing Degree in Promoting C−C Coupling in Electrochemical CO2 Reduction Reaction on Cu‐based Catalysts
Authors: Wang Yinuo , Yang Fei , Xu Hongming , Jang Juhee , Delmo Ernest P. , Qiu Xiaoyi , Ying Zhehan , Gao Ping , Zhu Shangqian , Gu M. Danny , Shao Minhua
Published: February 2024

Cu‐based catalysts have been identified as the most promising candidates for generation of C2+ products in electrochemical CO2 reduction reaction. Defect engineering in catalysts is a widely employed strategy for promoting C−C coupling on Cu. However, comprehensive understanding of defect structure‐to‐activity relationship has not been obtained. In this study, controllable defects generation is achieved, which leads to a series of Cu‐based catalysts with various phase mixing degrees. It is observed that the Faradaic efficiency toward C2+ products increases with the phase mixing degree, reaching 81 % at maximum. In situ infrared absorption spectroscopy reveals that the catalysts with higher phase mixing degree tend to form *CO more easily and possess higher retention of *CO under high overpotential window, thereby promoting C−C coupling. This work sheds new light on the relationship between defects and C−C coupling, and the rational developed of more advanced Cu‐base catalysts.
Confining Polymer Electrolyte in MOF for Safe and High‐Performance All‐Solid‐State Sodium Metal Batteries
Authors: Zhang Jinfang , Wang Yuanyuan , Xia Qingbing , Li Xiaofeng , Liu Bin , Hu Tuoping , Tebyetekerwa Mike , Hu Shengliang , Knibbe Ruth , Chou Shulei
Published: February 2024

Nanoconfined polymer molecules exhibit profound transformations in their properties and behaviors. Here, we present the synthesis of a polymer‐in‐MOF single ion conducting solid polymer electrolyte, where polymer segments are partially confined within nanopores ZIF‐8 particles through Lewis acid‐base interactions for solid‐state sodium‐metal batteries (SSMBs). The unique nanoconfinement effectively weakens Na ion coordination with the anions, facilitating the Na ion dissociation from salt. Simultaneously, the well‐defined nanopores within ZIF‐8 particles provide oriented and ordered migration channels for Na migration. As a result, this pioneering design allows the solid polymer electrolyte to achieve a Na ion transference number of 0.87, Na ion conductivity of 4.01×10−4 S cm−1, and an extended electrochemical voltage window up to 4.89 V vs. Na/Na+. The assembled SSMBs (with Na3V2(PO4)3 as the cathode) exhibit dendrite‐free Na‐metal deposition, promising rate capability, and stable cycling performance with 96 % capacity retention over 300 cycles. This innovative polymer‐in‐MOF design offers a compelling strategy for advancing high‐performance and safe solid‐state metal battery technologies.
Sulphur‐Boosted Active Hydrogen on Copper for Enhanced Electrocatalytic Nitrate‐to‐Ammonia Selectivity
Authors: Xu Yue , Cheng Chuanqi , Zhu Jiewei , Zhang Bin , Wang Yuting , Yu Yifu
Published: February 2024

Electrocatalytic nitrate reduction to ammonia is a promising approach in term of pollutant appreciation. Cu‐based catalysts performs a leading‐edge advantage for nitrate reduction due to its favorable adsorption with *NO3. However, the formation of active hydrogen (*H) on Cu surface is difficult and insufficient, leading to the significant generation of by‐product NO2−. Herein, sulphur doped Cu (Cu−S) is prepared via an electrochemical conversion strategy and used for nitrate electroreduction. The high Faradaic efficiency (FE) of ammonia (~98.3 %) and an extremely low FE of nitrite (~1.4 %) are achieved on Cu−S, obviously superior to its counterpart of Cu (FENH3: 70.4 %, FENO2−: 18.8 %). Electrochemical in situ characterizations and theoretical calculations indicate that a small amount of S doping on Cu surface can promote the kinetics of H2O dissociation to active hydrogen. The optimized hydrogen affinity validly decreases the hydrogenation kinetic energy barrier of *NO2, leading to an enhanced NH3 selectivity.
Multielectron Redox‐Bipolar Tetranitroporphyrin Macrocycle Cathode for High‐Performance Zinc‐Organic Batteries
Authors: Song Ziyang , Miao Ling , Duan Hui , Lv Yaokang , Gan Lihua , Liu Mingxian
Published: February 2024

Bipolar organics fuse the merits of n/p‐type redox reactions for better Zn‐organic batteries (ZOBs), but face the capacity plafond due to low density of active units and single‐electron reactions. Here we report multielectron redox‐bipolar tetranitroporphyrin (TNP) with quadruple two‐electron‐accepting n‐type nitro motifs and dual‐electron‐donating p‐type amine moieties towards high‐capacity‐voltage ZOBs. TNP cathode initiates high‐kinetics, hybrid anion–cation 10e− charge storage involving four nitro sites coordinating with Zn2+ ions at low potential and two amine species coupling with SO42− ions at high potential. Consequently, Zn||TNP battery harvests high capacity (338 mAh g−1), boosted average voltage (1.08 V), and outstanding energy density (365 Wh kg−1TNP). Moreover, the extended π‐conjugated TNP macrocycle achieves anti‐dissolution in electrolytes, prolonging the battery life to 50,000 cycles at 10 A g−1 with 71.6 % capacity retention. This work expands the chemical landscape of multielectron redox‐bipolar organics for state‐of‐the‐art ZOBs.
Formamidinium Lead Iodide‐Based Inverted Perovskite Solar Cells with Efficiency over 25 % Enabled by An Amphiphilic Molecular Hole‐Transporter
Authors: Zhang Huidong , Zhang Shuo , Ji Xiaoyu , He Jingwen , Guo Huanxin , Wang Songran , Wu Wenjun , Zhu Wei‐Hong , Wu Yongzhen
Published: February 2024

Formamidinium lead iodide (FAPbI3) represents an optimal absorber material in perovskite solar cells (PSCs), while the application of FAPbI3 in inverted‐structured PSCs has yet to be successful, mainly owing to its inferior film‐forming on hydrophobic or defective hole‐transporting substrates. Herein, we report a substantial improvement of FAPbI3‐based inverted PSCs, which is realized by a multifunctional amphiphilic molecular hole‐transporter, (2‐(4‐(10H‐phenothiazin‐10‐yl)phenyl)‐1‐cyanovinyl)phosphonic acid (PTZ−CPA). The phenothiazine (PTZ) based PTZ−CPA, carrying a cyanovinyl phosphonic acid (CPA) group, forms a superwetting hole‐selective underlayer that enables facile deposition of high‐quality FAPbI3 thin films. Compared to a previously established carbazole‐based hole‐selective material (2‐(3,6‐dimethoxy‐9H‐carbazol‐9‐yl)ethyl)phosphonic acid (MeO−2PACz), the crystallinity of FAPbI3 is enhanced and the electronic defects are passivated by the PTZ−CPA more effectively, resulting in remarkable increases in photoluminescence quantum yield (four‐fold) and Shockley‐Read‐Hall lifetime (eight‐fold). Moreover, the PTZ−CPA shows a larger molecular dipole moment and improved energy level alignment with FAPbI3, benefiting the interfacial hole‐collection. Consequently, FAPbI3‐based inverted PSCs achieve an unprecedented efficiency of 25.35 % under simulated air mass 1.5 (AM1.5) sunlight. The PTZ−CPA based device shows commendable long‐term stability, maintaining over 90 % of its initial efficiency after continuous operation at 40 °C for 2000 hours.
Ultrathin Two‐Dimensional Porous Fullerene Membranes for Ultimate Organic Solvent Separation
Authors: Chen Xiaofang , Mu Yifang , Jin Chunxin , Wei Yayu , Hao Jinlin , Wang Huanting , Caro Jürgen , Huang Aisheng
Published: February 2024

Two‐dimensional (2D) materials with high chemical stability have attracted intensive interest in membrane design for the separation of organic solvents. As a novel 2D material, polymeric fullerenes (C60)∞ with distinctive properties are very promising for the development of innovative membranes. In this work, we report the construction of a 2D (C60)∞ nanosheet membrane for organic solvent separation. The pathways of the (C60)∞ nanosheet membrane are constructed by sub‐1‐nm lateral channels and nanoscale in‐plane pores created by the depolymerization of the (C60)∞ nanosheets. Attributing to ordered and shortened transport pathways, the ultrathin porous (C60)∞ membrane is superior in organic solvent separation. The hexane, acetone, and methanol fluxes are up to 1146.3±53, 900.4±41, and 879.5±42 kg ⋅ m−2 ⋅ h−1, respectively, which are up to 130 times higher than those of the state‐of‐the‐art membranes with similar dye rejection. Our findings demonstrate the prospect of 2D (C60)∞ as a promising nanofiltration membrane in the separation of organic solvents from macromolecular compounds such as dyes, drugs, hormones, etc.
Homoselective synthesis of tetrazole derivatives using copper complex anchored on mesoporous KIT‐6 as a reusable, highly efficient, and environmentally green nanocatalyst
Authors: Darabi Mitra , Nikoorazm Mohsen , Tahmasbi Bahman , Ghorbani‐Choghamarani Arash
Published: February 2024

In this article, the mesoporous silica framework of KIT‐6 was synthesized and, then its surface was modified using 3‐aminopropyltrimethoxysilane (APTMS). The new KIT‐6@DABP@Cu nanocatalyst was then prepared by anchoring the copper complex on modified mesoporous KIT‐6. The nanocatalyst was identified using several techniques, including FT‐IR, WDX, AAS, SEM, TGA, XRD, EDS, and BET. The physical properties, such as size, shape, and morphology of the nanocatalyst were studied by SEM analysis. The elemental composition of KIT‐6@DABP@Cu nanocatalyst was described using wavelength dispersive X‐ray spectroscopy (WDX) and EDS. FT‐IR spectroscopy was used to characterize the functional groups in the structure of the nanoparticles. The stability of KIT‐6@DABP@Cu nanocatalyst was studied by TGA at high temperatures. Also, the surface area, total volume, and average diameter of pores of the nanocatalyst were determined using Brunauer–Emmett–Teller (BET) analysis. The KIT‐6@DABP@Cu catalyst was found to be a new, highly effective, and green catalyst for the synthesizing of 5‐substituted‐tetrazoles using nitriles and sodium azide (NaN3) catalyzed in polyethyleneglycol‐400 (PEG‐400) as a green solvent. This heterogeneous catalyst showed good recyclability for up to five consecutive cycles without notable loss of its catalytic efficiency.
Unveiling the mutual effects of hydroxyl and dibenzhydryl groups in α‐diimino‐nickel precatalysts for direct synthesis of polyethylene elastomers
Authors: Wang Xinyu , Qin Lidong , Mahmood Qaiser , Yuan Shifang , Wang Yizhou , Zou Song , Yuan Rongyan , Liang Tongling , Sun Wen‐Hua
Published: February 2024

The properties and practical applications of polyethylene are closely associated with the polymer molecular weight, polydispersity, degree of branching, and the type of branches and its arrangement within microstructure. In this study, a set of structurally diverse unsymmetrical 1‐(2,6‐dibenzhydryl‐4‐hydroxylphenylimino)‐2‐(2,6‐(R)‐4‐(R1)phenylimino)acenaphthene‐nickel dibromide precatalysts (where Ni2Me [R = Me, R1 = H], Ni2Et [R = Et, R1 = H], Ni2iPr [R = iPr, R1 = H], Ni3Me [R, R1 = Me], Ni2Et,Me [R = Et, R1 = Me]) has been prepared and studied for ethylene polymerization. Molecular structure analysis of Ni2Me and Ni2Et complexes revealed distorted tetrahedral geometries at nickel. The polymerization activities are extremely high for all precatalysts upon activation with either EASC or MMAO aluminum reagents, a trend notably pronounced in the case of the EASC‐activated systems, entering activity in the range of 10 million g mol−1 h−1 at 30°C. The Ni2Me demonstrated exceptional performance at higher temperatures, achieving an activity of 2.4 × 106 g mol−1 h−1 at 100°C and generated high molecular weight polyethylene (Mw = 105 g mol−1) with narrow polymer dispersity across all reaction temperatures (Ð ≈ 1.5). High temperature 13C NMR spectra identified 97–142/1000C branches in resulting polyethylene, a feature significantly dependent on the reaction temperature. In terms of mechanical properties, stress–strain analysis indicated that polyethylene synthesized at lower temperatures displayed superior tensile strength compared with that produced at higher reaction temperatures, while a reverse trend was observed in strain recovery analysis. The high strain recovery (up to 72%) of these polyethylene highlights the characteristic properties of thermoplastic elastomers.
Synthesis of FePP@MoS2@Ni‐MOF composites for improving thermal and flame retardant safety properties of polyurea
Authors: Lin Jiayu , Hou Yongbo , Ding Lailong , Wang Yifan , Hu Jinhu , Dong Peisong , Wang Qin , Ma Mingliang
Published: February 2024

Polyurea (PUA) is widely used as a coating in construction, tunnels, bridges, and other fields because of its excellent performance. However, its combustion emits toxic gases and smoke, hindering escape and posing potential fatality risks. Enhancing the flame retardancy of PUA is crucial for safety and expanding its applications. The synthesis of two‐dimensional FePP nanosheets was reported in this paper, employing the solvothermal method, followed by the sequential growth of MoS2 and Ni‐MOF to establish a multilayer composite structure. The elemental composition and morphology of the synthesized FePP@MoS2@Ni‐MOF flame retardants were characterized and analyzed. The flame retardant properties of polyurea composites with varying amounts of FePP@MoS2@Ni‐MOF were investigated using Cone calorimeter tests. The results showed that the prepared flame retardant had good thermal stability and significantly improved fire safety properties. The PUA/FePP@MoS2@Ni‐MOF 3.0 composite exhibited notable improvements compared to pure PUA. Specifically, the peak heat release rate, total heat release rate and peak smoke production rate were reduced by 39.76%, 29.33% and 17.86%, respectively, while total smoke production and total CO production (COP) were reduced by 21.30% and 54.47%. This study provides new insights and experimental basis for the technological development of novel flame retardant coating materials.
Improved performance of the ultrafiltration membranes by simple modification with air plasma treatment and polymeric deposition
Authors: Marques Ingrid R. , Leite Monique Juna L. , Piacentini Artur M. , Binder Cristiano , Dotto Marta E. R. , Ambrosi Alan , Di Luccio Marco , da Costa Cristiane
Published: February 2024

This study seeks to increase the antifouling properties of fluorinated polyvinylidene (PVDF) membranes through the synergistic application of plasma treatment and polymer deposition, employing polymerizations of polyvinylpyrrolidone (PVP) and polyethyleneimine (PEI). The results show remarkable success in modifications, presenting exceptional performance. Two distinct surface modification methods, plasma treatment and polymer deposition, were used to improve the antifouling properties and filtration performance of PVDF membranes. The plasma used was a discharge dielectric barrier using ambient air as gas, and hydrophilic polymers, PVP, and PEI. The results outlined changes in membrane roughness with a significant roughness reduction of up to 43% evident based on topographic and morphological analyses. Hydraulic permeability analysis revealed a substantial 35‐fold increase, indicating a notable improvement in performance. All treated membranes exhibited higher water affinity and superior performance during 12‐h ultrafiltration compared to their untreated counterparts. After chemical cleaning, water flux recovery exceeded 85% for all treated membranes, indicating the inherent antifouling properties of the surface.