Molecular oxidation-reduction junctions for artificial photosynthetic overall reaction.

Constructing redox semiconductor heterojunction photocatalysts is the most effective and important means to complete the artificial photosynthetic overall reaction (i.e., coupling CO2 photoreduction and water photo-oxidation reactions). However, multiphase hybridization essence and inhomogeneous junction distribution in these catalysts extremely limit the diverse design and regulation of the modes of photogenerated charge separation and transfer pathways, which are crucial factors to improve photocatalytic performance. Here, we develop molecular oxidation-reduction (OR) junctions assembled with oxidative cluster (PMo12, for water oxidation) and reductive cluster (Ni5, for CO2 reduction) in a direct (d-OR), alternant (a-OR), or symmetric (s-OR) manner, respectively, for artificial photosynthesis. Significantly, the transfer direction and path of photogenerated charges between traditional junctions are obviously reformed and enriched in these well-defined crystalline catalysts with monophase periodic distribution and thus improve the separation efficiency of the electrons and holes. In particular, the charge migration in s-OR shows a periodically and continuously opposite mode. It can inhibit the photogenerated charge recombination more effectively and enhance the photocatalytic performance largely when compared with the traditional heterojunction models. Structural analysis and density functional theory calculations disclose that, through adjusting the spatial arrangement of oxidation and reduction clusters, the energy level and population of the orbitals of these OR junctions can be regulated synchronously to further optimize photocatalytic performance. The establishment of molecular OR junctions is a pioneering important discovery for extremely improving the utilization efficiency of photogenerated charges in the artificial photosynthesis overall reaction.

Best evidence summary for prevention and management of enteral feeding intolerance in critically ill patients.

AIM: To evaluate and summarize the evidence for prevention and management of enteral feeding intolerance in critically ill patients and provide reference for clinical practice. DESIGN: This study was an evidence summary followed by the evidence summary reporting standard of Fudan University Center for Evidence-based Nursing. METHODS: Current literatures were systematically searched for the best evidence for prevention and management of enteral feeding intolerance in critically ill patients. Literature types included clinical guidelines, best practice information sheets, expert consensuses, systematic reviews, evidence summaries and cohort studies. DATA SOURCES: UpToDate, BMJ Best Practice, Joanna Briggs Institute, Guidelines International Network, National Institute for Health and Care Excellence, Registered Nurses Association of Ontario, Scottish Intercollegiate Guidelines Network, the Cochrane Library, Embase, PubMed, Sinomed, Web of Science, Yi Maitong Guidelines Network, DynaMed, MEDLINE, CNKI, WanFang database, Chinese Medical Journal Full-text Database, European Society for Clinical Nutrition and Metabolism website, the American Society for Parenteral and Enteral Nutrition website were searched from January 2012 to April 2023. RESULTS: We finally identified 18 articles that had high-quality results. We summarized the 24 pieces of best evidence from these articles, covering five aspects: screening and assessment of the risk of enteral nutritional tolerance; formulation of enteral nutrition preparations; enteral nutritional feeding implementation; feeding intolerance symptom prevention and management; and multidisciplinary management. Of these pieces of evidence, 19 were 'strong' and 5 were 'weak', 7 pieces of evidence were recommended in level one and 4 pieces of evidence were recommended in level two. CONCLUSION: The following 24 pieces of evidence for prevention and management of enteral feeding intolerance in critically ill patients were finally recommended. However, as these evidences came from different countries, relevant factors such as the clinical environment should be evaluated before application. Future studies should focus on more specific symptoms of feeding intolerance and more targeted prevention design applications. IMPLICATIONS FOR THE PROFESSION AND PATIENT CARE: The clinical medical staffs are recommended to take evidence-based recommendations for the implementation of standardized enteral nutrition to improve patient outcomes and decrease gastrointestinal intolerance in critically ill patients. IMPACT: The management of enteral nutrition feeding intolerance has always been a challenge and difficulty in critically ill patients. This study summarizes 24 pieces of the best evidence for prevention and management of enteral nutrition feeding intolerance in critically ill patients. Following and implementing these 24 pieces of evidence is beneficial to the prevention and management of feeding intolerance in clinical practice. The 24 pieces of evidence include five aspects, including screening and assessment of the risk of enteral nutritional tolerance, formulation of enteral nutrition preparations, enteral nutritional feeding implementation, feeding intolerance symptom prevention and management and multidisciplinary management. These five aspects constitute a good implementation process. Screening and assessment of enteral nutritional tolerance throughout intervention are important guarantees for developing a feasible nutrition program in critically ill patients. This study will be benefit to global medical workers in the nutritional management of critically ill patients. REPORTING METHOD: This evidence summary followed the evidence summary reporting specifications of Fudan University Center for Evidence-based Nursing, which were based on the methodological process for the summary of the evidence produced by the Joanna Briggs Institute (JBI). The reporting specifications include problem establishment, literature retrieval, literature screening, literature evaluation, the summary and grading of evidence and the formation of practical suggestions. This study was based on the evidence summary reporting specifications of the Fudan University Center for the Evidence-based Nursing, the register name is 'Best evidence summary for prevention and management of enteral feeding intolerance in critically ill patients', the registration number is 'ES20231823'.

Calix[4]arene-Functionalized Titanium-Oxo Compounds for Perceiving Differences in Catalytic Reactivity Between Mono- and Multimetallic Sites.

While the difference in catalytic reactivity between mono- and multimetallic sites is often attributed to more than just the number of active sites, still few catalyst model systems have been developed to explore more underlying causal factors. In this work, we have elaborately designed and constructed three stable calix[4]arene (C4A)-functionalized titanium-oxo compounds, Ti-C4A, Ti4-C4A, and Ti16-C4A, with well-defined crystal structures, increasing nuclearity, and tunable light absorption capacity and energy levels. Among them, Ti-C4A and Ti16-C4A can be taken as model catalysts to compare the differences in reactivity between mono- and multimetallic sites. Taking CO2 photoreduction as the basic catalytic reaction, both compounds can achieve CO2-to-HCOO- conversion with high selectivity (close to 100%). Moreover, the catalytic activity of multimetallic Ti16-C4A is up to 2265.5 µmol g-1 h-1, which is at least 12 times higher than that of monometallic Ti-C4A (180.0 µmol g-1 h-1), and is the best-performing crystalline cluster-based photocatalyst known to date. Catalytic characterization combined with density functional theory calculations shows that in addition to the advantage of having more metal active sites (for adsorption and activation of more CO2 molecules), Ti16-C4A can effectively reduce the activation energy required for the CO2 reduction reaction by completing the multiple electron-proton transfer process rapidly with synergistic metal-ligand catalysis, thus exhibiting superior catalytic performance to that of monometallic Ti-C4A. This work provides a crystalline catalyst model system to explore the potential factors underlying the difference in catalytic reactivity between mono- and multimetallic sites.

Cu-MOFs with Rich Open Metal and F Sites for Separation of C2H2 from CO2 and CH4.

Herein, we used the 4-fluoro-[1,1'-biphenyl]-3,4',5-tricarboxylic acid (H3fbptc) ligand to design and construct a new metal-organic framework (MOF), [Cu3(fbptc)2(H2O)3]·3NMP (1), which possesses rich accessible metal sites and F functional groups in the porous walls and shows high uptake for C2H2 (119.3 cm3 g-1) and significant adsorption selectivity for C2H2 over CH4 (14.4) and CO2 (3.6) at 298 K and 100 kPa. In particular, for the gas mixtures of C2H2-CH4 and C2H2-CO2, the MOF reveals large breakthrough time ratios (C2H2/CH4 = 13, C2H2/CO2 = 5.9), which are particularly prominent in dynamic breakthrough experiments, also confirming the excellent potential for the practical separation of C2H2 from two-component mixtures (C2H2-CH4 and C2H2-CO2) and even three-component mixtures (C2H2-CO2-CH4).

Theoretical study of NiI-NiIII cycle mediated by heterogeneous zinc in C-N cross-coupling reaction.

Photoredox/transition-metal dual catalysis could efficiently construct C-N bonds by a cross-coupling reaction. The limitations of low recovery, low utilization rate and high cost have hindered the application and development of low-cost and efficient transition metal catalytic cycles. The integration of heterogeneous metal and transition metal catalysis is an appealing alternative to realize the oxidation state modulation of active species. With the support of density functional theory (DFT) calculation, we have explored the mechanistic details of Ni-catalyzed C-N cross-coupling of aryl bromide and cyclic amine assisted by zinc powder. Zinc successfully regulates the oxidation state of NiII → NiI, thus achieving the NiI-NiIII-NiI catalytic cycle in the absence of light. In comparison, when the Ni(0) complex is employed as the initial catalyst, organic zinc reagents can still be involved in the transmetalation process to accelerate the cross-coupling reaction. We hope that such computational studies can provide theoretical reference for the design and development of low-cost and efficient catalytic systems for C-N cross-couplings.

Low Band Gap Benzoxazole-Linked Covalent Organic Frameworks for Photo-Enhanced Targeted Uranium Recovery.

The inherent features of covalent organic frameworks (COFs) make them highly attractive for uranium recovery applications. A key aspect yet to be explored is how to improve the selectivity and efficiency of COFs for recovering uranium from seawater. To achieve this goal, a series of robust and hydrophilic benzoxazole-based COFs is developed (denoted as Tp-DBD, Bd-DBD, and Hb-DBD) as efficient adsorbents for photo-enhanced targeted uranium recovery. Benefiting from the hydroxyl groups and the formation of benzoxazole rings, the hydrophilic Tp-DBD shows outstanding stability and chemical reduction properties. Meanwhile, the synergistic effect of the hydroxyl groups and the benzoxazole rings in the π-conjugated frameworks significantly decrease the optical band gap, and improve the affinity and capacity to uranium recovery. In seawater, the adsorption capacity of uranium is 19.2× that of vanadium, a main interfering metal in uranium extraction.

Superiority of Iridium Photocatalyst and Role of Quinuclidine in Selective α-C(sp3)-H Alkylation: Theoretical Insights.

Recent experimental work reported that visible-light photoredox catalysis coupled with primary sulfonamides and electron-deficient alkenes could efficiently construct C-C bonds at the α-position of primary amine derivatives under mild conditions. Here, a systematic study was conducted to explore the non-negligible excited-state single-electron-transfer (SET) processes and the catalytic cycle. Hydrogen atom transfer (HAT) catalysis containing different site-selective functionalization, involved as a critical process during the reaction, was computationally characterized. The superiorities of iridium-based photoredox catalysts in terms of photoabsorption properties, phosphorescence rates, and electron-transfer rates for SET processes were focused on. In addition, the function of quinuclidine in the entire photocatalytic reaction was also probed. These intrinsic properties and detailed insights into the mechanism are supposed to be helpful to the understanding of the C-C bond functionalization reaction and the future application of the iridium-based photoredox catalyst.

Regenerable Covalent Organic Frameworks for Photo-enhanced Uranium Adsorption from Seawater.

Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. Herein, a semiconducting covalent organic framework (named NDA-TN-AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA-TN-AO with a high anti-biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV , thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA-TN-AO to uranium in seawater reaches 6.07 mg g-1 , which is 1.33 times of that in dark. The NDA-TN-AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.

Evidence for the Involvement of Auxin, Ethylene and ROS Signaling During Primary Root Inhibition of Arabidopsis by the Allelochemical Benzoic Acid.

Allelopathy is mediated by plant-derived secondary metabolites (allelochemicals) which are released by donor plants and affect the growth and development of receptor plants. The plant root is the first organ which senses soil allelochemicals this results in the production of a shorter primary root. However, the mechanisms underlying this process remain elusive. Here, we report that a model allelochemical benzoic acid (BA) inhibited primary root elongation of Arabidopsis seedlings by reducing the sizes of both the meristem and elongation zones, and that auxin signaling affected this process. An increase in auxin level in the root tips was associated with increased expression of auxin biosynthesis genes and auxin polar transporter AUX1 and PIN2 genes under BA stress. Mutant analyses demonstrated that AUX1 and PIN2 rather than PIN1 were required for the inhibition of primary root elongation during BA exposure. Furthermore, BA stimulated ethylene evolution, whereas blocking BA-induced ethylene signaling with an ethylene biosynthesis inhibitor (Co2+), an ethylene perception antagonist (1-methylcyclopropene) or ethylene signaling mutant lines etr1-3 and ein3eil1 compromised BA-mediated inhibition of root elongation and up-regulation of auxin biosynthesis-related genes together with AUX1 and PIN2, indicating that ethylene signal was involved in auxin-mediated inhibition of primary root elongation during BA stress. Further analysis revealed that the BA-induced reactive oxygen species (ROS) burst contributed to BA-mediated root growth inhibition without affecting auxin and ethylene signals. Taken together, our results reveal that the allelochemical BA inhibits root elongation by increasing auxin accumulation via stimulation of auxin biosynthesis and AUX1/PIN2-mediated auxin transport via stimulation of ethylene production and an auxin/ethylene-independent ROS burst.

Auxin signalling of Arachis hypogaea activated by colonization of mutualistic fungus Phomopsis liquidambari enhances nodulation and N2 -fixation.

Beneficial fungal and rhizobial symbioses share commonalities in phytohormones responses, especially in auxin signalling. Mutualistic fungus Phomopsis liquidambari effectively increases symbiotic efficiency of legume peanut (Arachis hypogaea L.) with another microsymbiont, bradyrhizobium, but the underlying mechanisms are not well understood. We quantified and manipulated the IAA accumulation in ternary P. liquidambari-peanut-bradyrhizobial interactions to uncover its role between distinct symbioses. We found that auxin signalling is both locally and systemically induced by the colonization of P. liquidambari with peanut and further confirmed by Arabidopsis harbouring auxin-responsive reporter, DR5:GUS, and that auxin action, including auxin transport, is required to maintain fungal symbiotic behaviours and beneficial traits of plant during the symbiosis. Complementation and action inhibition experiments reveal that auxin signalling is involved in P. liquidambari-mediated nodule development and N2 -fixation enhancement and symbiotic gene activation. Further analyses showed that blocking of auxin action compromised the P. liquidambari-induced nodule phenotype and physiology changes, including vascular bundle development, symbiosome and bacteroids density, and malate concentrations, while induced the accumulation of starch granules in P. liquidambari-inoculated nodules. Collectively, our study demonstrated that auxin signalling activated by P. liquidambari symbiosis is recruited by peanut for bradyrhizobial symbiosis via symbiotic signalling pathway activation and nodule carbon metabolism enhancement.

Photocatalytic aerobic oxidation of C(sp3)-H bonds.

In modern industries, the aerobic oxidation of C(sp3)-H bonds to achieve the value-added conversion of hydrocarbons requires high temperatures and pressures, which significantly increases energy consumption and capital investment. The development of a light-driven strategy, even under natural sunlight and ambient air, is therefore of great significance. Here we develop a series of hetero-motif molecular junction photocatalysts containing two bifunctional motifs. With these materials, the reduction of O2 and oxidation of C(sp3)-H bonds can be effectively accomplished, thus realizing efficient aerobic oxidation of C(sp3)-H bonds in e.g., toluene and ethylbenzene. Especially for ethylbenzene oxidation reactions, excellent catalytic capacity (861 mmol g cat-1) is observed. In addition to the direct oxidation of C(sp3)-H bonds, CeBTTD-A can also be applied to other types of aerobic oxidation reactions highlighting their potential for industrial applications.

Bridging the Homogeneous and Heterogeneous Catalysis by Supramolecular Metal-Organic Cages with Varied Packing Modes.

Integrating the advantages of homogeneous and heterogeneous catalysis has proved to be an optimal strategy for developing catalytic systems with high efficiency, selectivity, and recoverability. Supramolecular metal-organic cages (MOCs), assembled by the coordination of metal ions with organic linkers into discrete molecules, have performed solvent processability due to their tunable packing modes, endowing them with the potential to act as homogeneous or heterogeneous catalysts in different solvent systems. Here, the design and synthesis of a series of stable {Cu3} cluster-based tetrahedral MOCs with varied packing structures are reported. These MOCs, as homogeneous catalysts, not only show high catalytic activity and selectivity regardless of substrate size during the CO2 cycloaddition reaction, but also can be easily recovered from the reaction media through separating products and co-catalysts by one-step work-up. This is because that these MOCs have varied solubilities in different solvents due to the tunable packing of MOCs in the solid state. Moreover, the entire catalytic reaction system is very clean, and the purity of cyclic carbonates is as high as 97% without further purification. This work provides a unique strategy for developing novel supramolecular catalysts that can be used for homogeneous catalysis and recycled in a heterogeneous manner.

Photochromic radical states in 3D covalent organic frameworks with zyg topology for enhanced photocatalysis.

Covalent-organic frameworks (COFs) with photoinduced donor-acceptor (D-A) radical pairs show enhanced photocatalytic activity in principle. However, achieving long-lived charge separation in COFs proves challenging due to the rapid charge recombination. Here, we develop a novel strategy by combining [6 + 4] nodes to construct zyg-type 3D COFs, first reported in COF chemistry. This structure type exhibits a fused Olympic-rings-like shape, which provides a platform for stabilizing the photoinduced D-A radical pairs. The zyg-type COFs containing catalytically active moieties such as triphenylamine and phenothiazine (PTZ) show superior photocatalytic production rates of hydrogen peroxide (H2O2). Significantly, the photochromic radical states of these COFs show up to 400% enhancement in photocatalytic activity compared to the parent states, achieving a remarkable H2O2 synthesis rate of 3324 µmol g-1 h-1, which makes the PTZ-COF one of the best crystalline porous photocatalysts in H2O2 production. This work will shed light on the synthesis of efficient 3D COF photocatalysts built on topologies that can facilitate photogenerating D-A radical pairs for enhanced photocatalysis.

Green synthesis of bifunctional phthalocyanine-porphyrin cofs in water for efficient electrocatalytic CO2 reduction coupled with methanol oxidation.

Electrocatalytic CO2 reduction (ECR) coupled with organic oxidation is a promising strategy to produce high value-added chemicals and improve energy efficiency. However, achieving the efficient redox coupling reaction is still challenging due to the lack of suitable electrocatalysts. Herein, we designed two bifunctional polyimides-linked covalent organic frameworks (PI-COFs) through assembling phthalocyanine (Pc) and porphyrin (Por) by non-toxic hydrothermal methods in pure water to realize the above catalytic reactions. Due to the high conductivity and well-defined active sites with different chemical environments, NiPc-NiPor COF performs efficient ECR coupled with methanol oxidation reaction (MOR) (Faradaic efficiency of CO (FECO) = 98.12%, partial current densities of CO (jCO) = 6.14 mA cm-2 for ECR, FEHCOOH = 93.75%, jHCOOH = 5.81 mA cm-2 for MOR at low cell voltage (2.1 V) and remarkable long-term stability). Furthermore, experimental evidences and density functional theory (DFT) calculations demonstrate that the ECR process mainly conducts on NiPc unit with the assistance of NiPor, meanwhile, the MOR prefers NiPor conjugating with NiPc. The two units of NiPc-NiPor COF collaboratively promote the coupled oxidation-reduction reaction. For the first time, this work achieves the rational design of bifunctional COFs for coupled heterogeneous catalysis, which opens a new area for crystalline material catalysts.

A new metal-organic framework based on rare [Zn4F4] cores for efficient separation of C2H2.

Assembly via 1,4-benzenedicarboxylate linkers and Zn2+ ions afforded an MOF containing rare [Zn4F4] cubane core, showing excellent separation for C2H2-CO2 and C2H2-CH4 mixtures. Dynamic breakthrough experiments and grand canonical Monte Carlo calculations were carried out to confirm the feasibility of the MOF for the separation application of C2H2.

Different Protonic Species Affecting Proton Conductivity in Hollow Spherelike Polyoxometalates.

Polyoxometalates (POMs), which possess strong acidity and chemical stability, are promising solid proton conductors and potential candidates for proton exchange membrane fuel cell applications. To investigate how factors such as proton concentration and carrier affect the overall proton conduction, we have synthesized new compounds HImMo132 (Im, imidazole), HMeImMo132, ILMo132, and TBAMo132 with hollow structures and HImPMo12 with a solid spherelike structure. These crystal models were prepared by encapsulating POM with organic molecules with different proton contents. Among them, the single-crystal sample of the hollow structure HImMo132 containing more proton sources shows a high proton conductivity of 4.98 × 10-2 S cm-1, which was approximately 1 order of magnitude greater than that of the solid cluster HImPMo12 with the same proton sources and 3 orders of magnitude greater than that of the proton-free organic cation-encapsulated giant ball TBAMo132. This study provides a theoretical guidance toward designing and developing new-generation proton conductors and studying their performances at the molecular level.

Orthogonal reactivity of Ni(i)/Pd(0) dual catalysts for Ullmann C-C cross-coupling: theoretical insight.

Dual catalysis has become a desirable alternative because of the synergetic effect of two distinct catalysts, but little is known about the mechanism of dual catalysis and its effect on the high reactivity and selectivity. Here, a novel Ullmann C-C cross-coupling of bromobenzene and 4-methoxyphenyltriflate via nickel/palladium dual catalysis has been investigated using density functional theory. The orthogonal reactivity of NiI/Pd0 combination is the precondition and foundation of achieving such a Ullmann cross-coupling reaction. In the present dual catalysis, the NiI complex acts as the primary catalyst, while the Pd0 catalyst plays a decisive role in the cross-selectivity.

[Treatment of the Goebell-Stoeckel fascia lata sling operation for female stress urinary incontinence].

OBJECTIVE: To observe the efficacy and safety of the goebell-stoeckel fascia lata sling operation for female stress urinary incontinence. METHODS: Thirteen patients suffering from stress urinary incontinence (SUI) with prolapsed vagina were enrolled into this study. The average follow-up time was thirty months. The outcomes and complications after operation were analysed. RESULTS: All patients had complete cure. There were no vaginal bleeding, infection, rejection for surgery and no recurrent cases. Five patients had mild temporary dysuria, which disappeared within one month. CONCLUSION: The goebell-stoeckel fascia lata sling operation is an effective, safe, well-tolerated procedure for treatment of SUI.

[Modified type I thyroplasty for treating unilateral vocal cord paralysis].

OBJECTIVE: To explore a new surgical approach for treating unilateral vocal cord paralysis. METHODS: Five cases of unilateral vocal cord paralysis due to various causes were treated with modified type I thyroplasty. Laryngostroboscopy and electroglottography were performed before and after the operations. RESULTS: The vocal cords were shifted very close to the median line in all the 5 cases postoperatively as shown by laryngostroboscopy and electroglottography. Complete closure of the glottis was achieved. The patients had almost normal results of electroglottography, and the vocal sound nearly recovered normal or was significantly improved. CONCLUSION: Modified type I thyroplasty is effective, safe and easy in treating unilateral vocal cord paralysis.

Influence of root-exudates concentration on pyrene degradation and soil microbial characteristics in pyrene contaminated soil.

The effect of ryegrass (Lolium perenne L.) root-exudates concentration on pyrene degradation and the microbial ecological characteristics in the pyrene contaminated soil was investigated by simulating a gradually reducing concentration of root exudates with the distance away from root surface in the rhizosphere. Results showed that, after the root-exudates were added 15 d, the pyrene residue in contaminated soil responded nonlinearly in the soils with the same pyrene contaminated level as the added root-exudates concentration increased, which decreased first and increased latter with the increase of the added root-exudates concentration. The lowest pyrene concentration appeared when the root exudates concentration of 32.75 mg kg(-1) total organic carbon (TOC) was added. At the same time, changes of microbial biomass carbon (MBC, C(mic)) and microbial quotient (C(mic)/C(org)) were opposite to the trend of pyrene degradation as the added root-exudates concentration increased. Phospholipid fatty acid (PLFA) analysis revealed that bacteria was the dominating microbial community in pyrene contaminated soil, and the changing trends of pyrene degradation and bacteria number were the same. The changing trend of endoenzyme-dehydrogenase activity was in accordance with that of soil microbe, indicating which could reflect the quantitative characteristic of detoxification to pyrene by soil microbe. The changes in the soils microbial community and corresponding microbial biochemistry characteristics were the ecological mechanism influencing pyrene degradation with increasing concentration of the added root-exudates in the pyrene contaminated soil.