Organic Networks Research Articles

Super-fast iodine capture by an ionic covalent organic network (iCON) from aqueous and vapor media

Schematic representation of iCON-4 as an ion-exchange based adsorbent with high iodine uptake capacity in various media such as vapour phase and aqueous solution.

Photochemical and gas adsorption studies of Keggin polyoxometalate functionalized porous melamine terephthaldehyde material.

A compound containing a microporous melamine-terephthaldehyde framework is protonated by grinding with acetic acid, resulting in a mesoporous protonated melamine-terephthaldehyde network. The Keggin polyanion [PMo12O40]3- is then immobilized into this protonated melamine-terephthaldehyde network through a solid-state reaction. The polyanion interacts with the protonated microporous organic network through electrostatic interaction. Three different Keggin-melamine-terephthaldehyde materials were synthesized by varying the Keggin anion loading of 10 wt%, 15 wt% and 20 wt%. The Keggin-melamine-terephthaldehyde materials exhibit photochromism on irradiation with sunlight. The photochromism of the POM-organic hybrid material is due to reduction of the Keggin anion. The resulting blue reduced Keggin-melamine-terephthaldehyde materials are oxidized back by treatment with hydrogen peroxide. The N2, CO2 and H2 adsorption properties of all the synthesized materials, including protonated melamine-terephthaldehyde materials, were studied. The materials were characterized by IR, PXRD, DRS, TGA, EPR spectroscopy, and FESEM electron microscopy. The elemental composition was analysed with a CHN analyser and ICP-OES analysis.

Left ventricular assist device bridging to heart transplantation: Comparison of temporary versus durable support.

Since the revision of the United States heart allocation system, increasing use of mechanical circulatory support has been observed as a means to support acutely ill patients. We sought to compare outcomes between patients bridged to orthotopic heart transplantation (OHT) with either temporary (t-LVAD) or durable left ventricular assist devises (d-LVAD) under the revised system. The United States Organ Network database was queried to identify all adult OHT recipients who were bridged to transplant with either an isolated t-LVAD or d-LVAD from 10/18/2018 to 9/30/2020. The primary outcome was 1-year post-transplant survival. Predictors of mortality were also modeled, and national trends of LVAD bridging were examined across the study period. About 1,734 OHT recipients were analyzed, 1,580 (91.1%) bridged with d-LVAD and 154 (8.9%) bridged with t-LVAD. At transplant, the t-LVAD cohort had higher total bilirubin levels and greater prevalence of pre-transplant intravenous inotrope usage and mechanical ventilation. Median waitlist time was also shorter for t-LVAD. At 1 year, there was a non-significant trend of increased survival in the t-LVAD cohort (94.8% vs 90.1%; p=0.06). After risk adjustment, d-LVAD was associated with a 4-fold hazards for 1-year mortality (hazard ratio 3.96, 95% confidence interval 1.42-11.03; p=0.009). From 2018 to 2021, t-LVAD bridging increased, though d-LVAD remained a more common bridging strategy. Since the 2018 allocation change, there has been a steady increase in t-LVAD usage as a bridge to OHT. Overall, patients bridged with these devices appear to have least equivalent 1-year survival compared to those bridged with d-LVAD.

Simple lattice model of surface-confined metal–organic networks consisting of linear nitrogen-bearing molecules and transition metals

How do the size of nitrogen-bearing groups of the linker-molecule and the type of the coordinating metal center affect the phase behavior and thermal stability of surface-confined metal–organic layers?

Greenery and water structure before and after political system transformation. A Poznań city case study

The greenery and water structure, in the form of wedges cutting into the city, is a characteristic and unique element of Poznań’s urban model. Already before the Second World War, it became the matrix setting the framework for spatial and natural connections within and around the city. These areas were originally clearly demarcated and formed an organic network that permeated the built-up areas. It was this local network of linkages that was to have the greatest impact on the quality of urban living, climate improvement, biodiversity and the functional and spatial structure of the city.
 In the idea of the socialist city, ensuring access to green spaces for the masses, was one of the essential policy elements of the time. However, over time, in the various models of the city proposed by successive planners, these interconnections began to disappear and the individual bands were narrowed and sometimes discontinued altogether.
 This study aims to verify the urban planning models of the city of Poznań against the original idea of a wedge-ring system of greenery and water areas, before and after the political transformation in 1989.
 How does this original structure function today and how have the socio-economic changes that followed the fall of communism affect the greenery and water solutions proposed in the new city model?
 A comparative analysis of changes in green and water structure in the different spatial models of the city of Poznań, before and after the political transformation, makes it possible to observe the pace and directions of these changes. The analysis was based on the findings of the then-current master plans and on the studies of spatial development conditions and directions, which are an expression of the city’s spatial policy. It can be used to verify the assumptions made or even to change the current model of the city.

Engineering quantum states and electronic landscapes through surface molecular nanoarchitectures

Surfaces are at the frontier of every known solid. They provide versatile supports for functional nanostructures and mediate essential physicochemical processes. Being intimately related with 2D materials, interfaces and atomically thin films often feature distinct electronic states with respect to the bulk, which are key for many relevant properties, such as catalytic activity, interfacial charge-transfer, or crystal growth mechanisms. Of particular interest is reducing the surface electrons' dimensionality and spread with atomic precision, to induce novel quantum properties via lateral scattering and confinement. Both atomic manipulation and supramolecular principles provide access to custom-designed molecular superlattices, which tailor the surface electronic landscape and influence fundamental chemical and physical properties at the nanoscale. Herein, we review the confinement of surface state electrons focusing on their interaction with molecule-based scaffolds created by molecular manipulation and self-assembly protocols under ultrahigh vacuum conditions. Starting from the quasi-free 2D electron gas present at the (111)-terminated surface planes of noble metals, we illustrate the enhanced molecule-based structural complexity and versatility compared to simple atoms. We survey low-dimensional confining structures in the form of artificial lattices, molecular nanogratings or quantum dot arrays, which are constructed upon appropriate choice of their building constituents. Whenever the realized (metal-)organic networks exhibit long-range order, modified surface band structures with characteristic features emerge, revealing intriguing physical properties, such as discretization, quantum coupling or energy and effective mass renormalization. Such collective electronic states can be additionally modified by positioning guest species at the voids of open nanoarchitectures [...].

Gold nanoparticles decorated covalent organic polymer as a bimodal catalyst for total water splitting and nitro compound reduction

The design and construction of a bimodal catalyst with magnificent performance and high stability is a debatable one for total water splitting and nitro compound reduction. Herein, we report the synthesis of a covalent organic polymer network based on 1,4-phenylenediamine based covalent organic polymer (PD-COP) and its decoration with Au nanoparticles (Au NPs) as well as their confirmation using various analytical and surface techniques. The electrocatalytic activity toward total water-splitting reaction (OER and HER) in KOH solution (1.0 M) was investigated. In addition, the reduction of aromatic nitro compounds (4-nitrophenol (4-NP) and 2-nitroaniline (2-NA)) was carried out in the presence of NaBH4. Among the different electrocatalysts (PD-COP, Au@PD-COP-I, Au@PD-COP-II, Au@PD-COP-III and Au@PD-COP-IV) studied in this work, the Au@PD-COP-II demands a low overpotential of 288 mV and 184 mV to attain a 50-mA/cm2 geometrical current density with a lowest Tafel slope value of 56 and 85 mV/dec for OER and HER respectively. From the OER and HER phenomenal activity, a two-electrode system was constructed, and it needs a cell voltage of 1.615 V to conquer a current density of 10 mA/cm2 with outstanding stability for 34 h. The high electroactivity of Au@PD-COP-II may be allied with the presence of innumerable redox-active sites and high electrochemical active surface area (ECSA) towards effective water electrolysis. Further, the catalytic activity performed towards the reduction of 4-NP to 4-aminophenol (4-AP) and 2-NA to o-PDA (o-phenylenediamine), Au@PD-COP-II showed good catalytic activity with a reduction time of 20 and 14 min respectively.

Stimulating Zn2+ permselectivity for prominent zinc anode reversibility by designing a self-assembled artificial layer

Although zinc anodes are extensively adopted to meet aqueous energy storage, serious dendrite formation and side reaction resulting in inferior lifetime have hindered the application. In this work, a unique interfacial engineering is proposed by a self-assembled artificial layer tightly contact to the surface of zinc anode with Zn2+ permselectivity. Such artificial layer via a facile hydrolysis consists of nano inorganic particles well dispersed in organic network. The screening for the bound water of Zn2+ enables excellent anticorrosion during cycling and rest situation. Meanwhile, the modified zinc anode can reduce the Zn2+ nucleation barrier for uniform distribution, which is beneficial to dendrite suppression. Consequently, the modified zinc anodes in both symmetric and full cells exhibit prominently electrochemical reversibility. Specifically, with a cycling area capacity of 3.0 mAh cm−2 at 1.0 mA cm−2, the modified zinc anode can tolerate superior plating/stripping behavior over 1000 h. When it is coupled with vanadium pentoxide cathode, the performance advantage of the modified full-cell is still impressive and high-capacity retention of ∼84 % after 1200 cycles is achieved.

New Crosslinked Single-Ion Silica-PEO Hybrid Electrolytes.

New single-ion hybrid electrolytes have been synthetized via an original and simple synthetic approach combining Michael addition, epoxidation, and sol-gel polycondensation. We designed an organic PEO network as a matrix for the lithium transport, mechanically reinforced thanks to crosslinking inorganic (SiO1.5) sites, while highly delocalized anions based on lithium vinyl sulfonyl(trifluoromethane sulfonyl)imide (VSTFSILi) were grafted onto the inorganic sites to produce single-ion hybrid electrolytes (HySI). The influence of the electrolyte composition in terms of the inorganic/organic ratio and the grafted VSTFSILi content on the local structural organization, the thermal, mechanical, and ionic transport properties (ionic conductivity, transference number) are studied by a variety of techniques including SAXS, DSC, rheometry, and electrochemical impedance spectroscopy. SAXS measurements at 25 °C and 60 °C reveal that HySI electrolyte films display locally a spatial phase separation with domains composed of PEO rich phase and silica/VSTFSILi clusters. The size of these clusters increases with the silica and VSTFSILi content. A maximum ionic conductivity of 2.1 × 10-5 S·cm-1 at 80 °C has been obtained with HySI having an EO/Li ratio of 20. The Li+ ion transfer number of HySI electrolytes is high, as expected for a single-ion electrolyte, and comprises between 0.80 and 0.92.

Evaluating age-based eligibility thresholds for heart re-transplantation – an analysis of the united network for organ sharing database

Risk-adjusted survival after late heart re-transplantation may be comparable to primary transplant, but the efficacy of re-transplantation in older candidates is not established. We evaluated outcomes after heart re-transplantation in recipients > 60 years. We identified 1026 adult patients undergoing isolated heart re-transplantation between 2003 and 2020 from the United Network for Organ Sharing database. Older recipients (> 60 years, n=177) were compared to younger recipients (≤ 60 years, n=849). Five and ten-year post-transplant survival was estimated using the Kalpan-Meier method and adjusted with multivariable Cox models. Older recipients were more likely to be male and have diabetes or previous malignancies with higher baseline creatinine. They also more frequently required pre-transplant ECMO (11.9% vs. 6.8%, p=0.02) and received re-transplantation due to primary graft failure (13.6% vs. 8.5%, p=0.03). After the transplant, older recipients had a higher incidence of stroke (6.8% vs. 2.6%, p=0.01) and dialysis requirements (20.3% vs. 13.2%) before discharge (both p<0.05), and more frequently died from malignancy-related causes (16.3% vs. 3.9%, p<0.001). After adjustment, recipient age >60 was associated with an increased risk of both 5-year (HR 1.42, 95% CI 1.02-2.01, p=0.04) and 10-year mortality (HR 1.72, 95% CI 1.20-2.45, p=0.003). Restricted cubic spline showed a non-linear relationship between recipient age and 10-year mortality. Heart re-transplantation in recipients > 60 years has inferior outcomes compared to younger recipients. Strict patient selection and close follow-up are warranted to ensure the appropriate utilization of donor hearts and to improve long-term outcomes.

A Three-Dimensional Silicon-Diacetylene Porous Organic Radical Polymer

A Three-Dimensional Silicon-Diacetylene Porous Organic Radical Polymer

Reminding forgetful organic neuromorphic device networks

Organic neuromorphic device networks can accelerate neural network algorithms and directly integrate with microfluidic systems or living tissues. Proposed devices based on the bio-compatible conductive polymer PEDOT:PSS have shown high switching speeds and low energy demand. However, as electrochemical systems, they are prone to self-discharge through parasitic electrochemical reactions. Therefore, the network’s synapses forget their trained conductance states over time. This work integrates single-device high-resolution charge transport models to simulate entire neuromorphic device networks and analyze the impact of self-discharge on network performance. Simulation of a single-layer nine-pixel image classification network commonly used in experimental demonstrations reveals no significant impact of self-discharge on training efficiency. And, even though the network’s weights drift significantly during self-discharge, its predictions remain 100% accurate for over ten hours. On the other hand, a multi-layer network for the approximation of the circle function is shown to degrade significantly over twenty minutes with a final mean-squared-error loss of 0.4. We propose to counter the effect by periodically reminding the network based on a map between a synapse’s current state, the time since the last reminder, and the weight drift. We show that this method with a map obtained through validated simulations can reduce the effective loss to below 0.1 even with worst-case assumptions. Finally, while the training of this network is affected by self-discharge, a good classification is still obtained. Electrochemical organic neuromorphic devices have not been integrated into larger device networks. This work predicts their behavior under nonideal conditions, mitigates the worst-case effects of parasitic self-discharge, and opens the path toward implementing fast and efficient neural networks on organic neuromorphic hardware.

Coral growth anomalies, neoplasms, and tumors in the Anthropocene.

One of the most widespread coral diseases linked to anthropogenic activities and recorded on reefs worldwide is characterized by anomalous growth formations in stony corals, referred to as coral growth anomalies (GAs). The biological functions of GA tissue include limited reproduction, reduced access to resources, and weakened ability to defend against predators. Transcriptomic analyses have revealed that, in some cases, disease progression can involve host genes related to oncogenesis, suggesting that the GA tissues may be malignant neoplasms such as those developed by vertebrates. The number of studies reporting the presence of GAs in common reef-forming species highlights the urgency of a thorough understanding of the pathology and causative factors of this disease and its parallels to higher organism malignant tissue growth. Here, we review the current state of knowledge on the etiology and holobiont features of GAs in reef-building corals.

Triazine- and Heptazine-Based Porous Organic Polymer Networks for the Efficient Removal of Perfluorooctanoic Acid

Triazine- and Heptazine-Based Porous Organic Polymer Networks for the Efficient Removal of Perfluorooctanoic Acid

Optimal combinations of fluorescent vessel labeling and tissue clearing methods for three-dimensional visualization of vasculature.

Visualization of intact vasculatures is crucial to understanding the pathogeneses of different neurological and vascular diseases. Although various fluorescent vessel labeling methods have been used in combination with tissue clearing for three-dimensional (3D) visualization of different vascular networks, little has been done to quantify the labeling effect of each vessel labeling routine, as well as their applicability alongside various clearing protocols, making it difficult to select an optimal combination for finely constructing different vasculatures. Therefore, it is necessary to systematically assess the overall performance of these common vessel labeling methods combined with different tissue-clearing protocols. A comprehensive evaluation of the labeling quality of various vessel labeling routines in different organs, as well as their applicability alongside various clearing protocols, were performed to find the optimal combinations for 3D reconstruction of vascular networks with high quality. Four commonly-used vessel labeling techniques and six typical tissue optical clearing approaches were selected as candidates for the systematic evaluation. The vessel labeling efficiency, vessel labeling patterns, and compatibility of each vessel labeling method with different tissue-clearing protocols were quantitatively evaluated and compared. Based on the comprehensive evaluation results, the optimal combinations were selected for 3D reconstructions of vascular networks in several organs, including mouse brain, liver, and kidney. This study provides valuable insight on selecting the proper pipelines for 3D visualization of vascular networks, which may facilitate understanding of the underlying mechanisms of various neurovascular diseases.

Rational engineering of metal–organic coordination networks into facet‐controlled phosphides for overall water splitting

AbstractAlthough transition metal phosphide electrocatalysts display unique electronic structure that serves as functional centers for hydrogen evolution reaction, the synthesis of this class of materials for oxygen evolution remains a challenge due to the complex multielectron transfer pathways and sluggish reaction kinetics. This study details an in‐situ modification and transformation of cyanide‐bridged nickel‐iron (CN‐NiFe) organometallic hybrid into the preferential Fe2P phase with prevailing exposed faceted active centers by leveraging on the facile coordinate cleavage dynamics and compound reactivity of labile metal organic coordination frameworks. The resultant transition metal phosphide attains high electrochemical surface area, low Tafel slope, and low overpotential for the oxygen evolution reaction, while also demonstrating bifunctional electrocatalytic performance for overall water splitting. Comprehensive experimental studies and density functional theory calculations reveal that the exceptional catalytic activity originates from the transformation of framework metallic sites into preferential active sites allows an optimal adsorption of oxygen evolution reaction intermediates.image

Leukemia Diagnosis Using Deep Learning

Abstract: Leukemia is a deadly malignancy and there are two main types: acute and persistent. Each type has two subtypes: lymphoid and myeloid. There are a total of four subtypes of leukemia. This study proposes a new approach to the disease of all leukemia subtypes from the concept of small blood cells using convolutional effects on living neural organ networks (CNNs) that require large preparative files.

Increased severe primary graft dysfunction in left ventricular assist device patients following united network for organ sharing allocation changes.

In 2018, the United Network for Organ Sharing (UNOS) implemented a new heart allocation system which prioritized patients on temporary support devices and left-ventricular assist device (LVAD) patients with complications. These changes have the potential to impact outcomes for patients bridged to transplant with an LVAD. We performed a retrospective study of 168 adult heart transplant recipients at our center between 2016 and 2020 evaluating post-transplant outcomes before and after UNOS allocation changes. Donor and recipient data were retrieved from chart review and national databases. The primary outcome of this study was severe primary graft dysfunction (PGD) with secondary outcomes of 30-day readmission, 30-day mortality, and 1-year mortality. Incidence of severe PGD was similar in the overall cohort before and after the changes (10%vs. 15%, respectively, p=.3) and increased in the LVAD-bridged cohort (12%vs. 40%, respectively, p<.01). Secondary outcomes of readmission and survival were similar between all groups. Blood transfusion was predictive of severe PGD in multivariable modeling (OR 1.3 [1.11-1.59], p<.01).

Composites with a Novel Core–shell Structural Expanded Perlite/Polyethylene glycol Composite PCM as Novel Green Energy Storage Composites for Building Energy Conservation

Phase change materials (PCMs) in the thermal storage of construction can reduce energy waste by shrinking the diurnal daily temperature changes inside. The thermal energy storage (TES) wood-plastic composites (WPC) are manufactured by employing expanded perlite (EP) stabilized PEG as PCM and wood powder/high-density polyethylene (WF/HDPE) as a matrix. The novel type of shell-core PCM (E-shell PCM) was prepared through cation exchange and layer upon layer self-assembly built organic network structure, which was featured by the very thin shell and ultra-high content of active core materials. The unique protective shell gave the PCM high latent heat potential (136.40 J/g), good structural stability, and broad prospects for sustainable energy application. The TES WPC has excellent morphological stability, high phase transition heat and significant thermal stability, heat storage performance, and good mechanical strength. With the gradual increase of E-Shell PCM, the latent heat of TES WPC phase transition increases gradually, and the melting enthalpy and crystallization enthalpy reach 76.06 J/g and 74.61 J/g, respectively. Simultaneously, the introduction of EP promoted the composite heat and smoke suppression ability, suggested as a building material used for temperature control. Latent heat WPC may be utilized as biological building materials with high latent heat and strong mechanical properties to cut down on energy use and enhance interior comfort.

Postsynthetic Modification of NU-1000 for Designing a Polyoxometalate-Containing Nanocomposite with Enhanced Third-Order Nonlinear Optical Performance.

For the advancement of laser technologies and optical engineering, various types of new inorganic and organic materials are emerging. Metal-organic frameworks (MOFs) reveal a promising use in nonlinear optics, given the presence of organic linkers, metal cluster nodes, and possible delocalization of π-electron systems. These properties can be further enhanced by the inclusion of solely inorganic materials such as polyoxometalates as prospective low-cost electron-acceptor species. In this study, a novel hybrid nanocomposite, namely, SiW12@NU-1000 composed of SiW12 (H4SiW12O40) and Zr-based MOF (NU-1000), was assembled, completely characterized, and thoroughly investigated in terms of its nonlinear optical (NLO) performance. The third-order NLO behavior of the developed system was assessed by Z-scan measurements using a 532 nm laser. The effect of two-photon absorption and self-focusing was significant in both NU-1000 and SiW12@NU-1000. Experimental studies suggested a much superior NLO performance of SiW12@NU-1000 if compared to that of NU-1000, which can be assigned to the charge-energy transfer between SiW12 and NU-1000. Negligible light scattering, good stability, and facile postsynthetic fabrication method can promote the applicability of the SiW12@NU-1000 nanocomposite for various optoelectronic purposes. This research may thus open new horizons to improve and enhance the NLO performance of MOF-based materials through π-electron delocalization and compositing metal-organic networks with inorganic molecules as electron acceptors, paving the way for the generation of novel types of hybrid materials for prospective NLO applications.