Dynamic Structural Fluxionality in a Planar Tetracoordinate Carbon Cluster Stabilized by Boron Ligands.

The design of boron-based molecular rotors stems from boron-carbon binary clusters containing multiple planar hypercoordinate carbons (phCs, such as C2B8). However, the design of boron-coordinated phCs is challenging due to boron's tendency to occupy hypercoordinate centers more than carbon. Although this challenge has been addressed, the designed clusters of interest have not exhibited dynamic fluxionality similar to that of the initial C2B8. To address this issue, we report a σ/π doubly aromatic CB2H5+ cluster, the first global minimum containing a boron-coordinated planar tetracoordinate carbon atom with dynamic fluxionality. Dynamics simulations show that two ligand H atoms exhibit alternate rotation, resulting in an intriguing dynamic fluxionality in this cluster. Electronic structure analysis reveals the flexible bonding positions of the ligand H atoms because they do not participate in π delocalized bonding nor bond to any other non-carbon atom, highlighting this rotational fluxionality. Unprecedentedly, the fluxional process involves not only the usual conversion of the number of bonding atoms, but also the type of bonding (3c π bonds ↔ 4c σ bonds), which is an uncommon fluxional mechanism. The cluster represents an effort to apply phC species to molecular machines.

Deselenylative Acylation and Nitration of Monoselenides.

A deselenylative protocol that enables the construction of the C-C and C-N bonds has been disclosed. By using acyl chloride/AgOTf as an efficient acylation reagent, diarylselenides smoothly undergo deselenylative acylation to produce a series of aroyl compounds. In addition, deselenylative nitration can be enabled by a mild nitration reagent consisting of TsCl and AgNO3, furnishing a diverse array of nitroaromatic compounds.

Sialic acids as attachment factors in mosquitoes mediating Japanese encephalitis virus infection.

The role of Culex mosquitoes in the transmission of Japanese encephalitis virus (JEV) is crucial, yet the mechanisms of JEV infection in these vectors remain unclear. Previous research has indicated that various host factors participate in JEV infection. Herein, we present evidence that mosquito sialic acids enhance JEV infection both in vivo and in vitro. By treating mosquitoes and C6/36 cells with neuraminidase or lectin, the function of sialic acids is effectively blocked, resulting in significant inhibition of JEV infection. Furthermore, knockdown of the sialic acid biosynthesis genes in Culex mosquitoes also leads to a reduction in JEV infection. Moreover, our research revealed that sialic acids play a role in the attachment of JEV to mosquito cells, but not in its internalization. To further explore the mechanisms underlying the promotion of JEV attachment by sialic acids, we conducted immunoprecipitation experiments to confirm the direct binding of sialic acids to the last α-helix in JEV envelope protein domain III. Overall, our study contributes to a molecular comprehension of the interaction between mosquitoes and JEV and offers potential strategies for preventing the dissemination of flavivirus in natural environments.IMPORTANCEIn this study, we aimed to investigate the impact of glycoconjugate sialic acids on mosquito infection with Japanese encephalitis virus (JEV). Our findings demonstrate that sialic acids play a crucial role in enhancing JEV infection by facilitating the attachment of the virus to the cell membrane. Furthermore, our investigation revealed that sialic acids directly bind to the final α-helix in the JEV envelope protein domain III, thereby accelerating virus adsorption. Collectively, our results highlight the significance of mosquito sialic acids in JEV infection within vectors, contributing to a better understanding of the interaction between mosquitoes and JEV.

Biological agent exerts therapeutic effects by reversing abnormalities in amino acid metabolic pathways in psoriasis.

Psoriasis is a common chronic inflammatory skin disease with a complex pathogenesis involving immune system dysregulation and inflammation. Previous studies have indicated that metabolic abnormalities are closely related to the development and occurrence of psoriasis. However, the specific involvement of amino acid metabolism in the pathogenesis of psoriasis remains unclear. In this study, we conducted a comprehensive analysis of amino acid metabolism pathway changes in psoriasis patients using transcriptome data, genome-wide association studies (GWASs) data, and single-cell data. Our findings revealed 11 significant alterations in amino acid metabolism pathways within psoriatic lesions, with notable restorative changes observed after biological therapy. Branched-chain amino acids, tyrosine and arginine metabolism have a causal relationship with the occurrence of psoriasis and may play a crucial role by promoting the proliferation and differentiation of the keratinocytes or immune-related pathways. Activation of phenylalanine, tyrosine and tryptophan biosynthesis suggests a favourable prognosis of psoriasis after treatment. Additionally, we identified the abnormal metabolic pathways in specific cell types and key gene sets that contribute to amino acid metabolic disorders in psoriasis. Overall, our study enhances understanding of the role of metabolism in the pathogenesis of psoriasis and provides potential targets for developing new therapeutic strategies for the disease.

Efficacy and safety of patient-controlled epidural analgesia versus patient-controlled intravenous analgesia following open hepatectomy: A single-center retrospective study.

Background: Postoperative analgesia is an essential component of enhanced recovery after surgery following abdominal surgery. Studies comparing the effectiveness of epidural analgesia with that of other analgesic modalities after liver surgery have reported inconsistent results. Consequently, the use of epidural analgesia for open hepatectomy is controversial. Objective: The present single-center retrospective study aimed to compare the efficacy and safety of patient-controlled epidural analgesia (PCEA) and patient-controlled intravenous analgesia (PCIA) in adults undergoing open hepatectomy. Methods: Patients who underwent open hepatectomy between January 2018 to December 2019 at Zhongshan Hospital, Fudan University were retrospectively analyzed. Propensity score matching was used to adjust baseline information between the PCEA and PCIA groups. The primary outcome measure was scores of the numeric rating scales (NRSs) for resting, exercise, and nocturnal pain at postoperative 24 h (postoperative day 1 [POD1]) and 48 h (POD2). The secondary outcome indicators included postoperative nausea and vomiting (PONV), hypotension, pruritus, respiratory depression, functional activity score (FAS), effective analgesic pump compression ratio, analgesic relief rate, discontinuation of the analgesic pump, reasons for discontinuation of the analgesic pump, and patient satisfaction with postoperative analgesia. Results: The NRS scores of the PCEA group on POD1 were significantly lower than those of the PCIA group (P < 0.05). On POD2, the difference between the two groups was significant only for motion NRS scores (P < 0.05). The PCIA group had significantly more patients with lower FAS functional class than the PCEA group (P < 0.001). The effective analgesic pump compression ratio and the analgesic relief rate at 2 days after the surgery were lower in the PCEA group than in the PCIA group (P < 0.001). The incidence of pump discontinuation was higher in the PCEA group than in the PCIA group on POD2 (P = 0.044). Moreover, on POD1 and POD2, the PCEA group showed a higher incidence of pruritus and hypotension than the PCIA group (P < 0.001). Both groups showed no significant difference in PONV incidence. Conclusion: In patients undergoing open hepatectomy, PCEA was more effective than PCIA in relieving moderate to severe pain on POD1. However, improving the safety and effectiveness of PCEA remains a challenge.

Highly efficient capture of iodine vapor by [Mo3S13]2- intercalated layered double hydroxides.

From the swollen LDH, bulky [Mo3S13]2- anions are facilely introduced into the LDH interlayers to assemble the Mo3S13-LDH composite, which exhibits excellent iodine capture performance and good irradiation resistance. The positive-charged LDH layers may disperse the [Mo3S13]2- uniformly within the interlayers, providing abundant adsorption sites for effectively trapping iodine. The Mo-S bond serving as a soft Lewis base has strong affinity to I2 with soft Lewis acidic characteristic, which is conducive to improvement of iodine capture via physical sorption. Besides, chemisorption has a significant contribution to the iodine adsorption. The S22-/S2- in [Mo3S13]2- can reduce the I2 to [I3]- ions, which are facilely fixed within the LDH gallery in virtue of electrostatic attraction. Meanwhile, the S22-/S2- themselves are oxidized to S8 and SO42-, while Mo4+ is oxidized (by O2 in air) to Mo6+, which combines with SO42- forming amorphous Mo(SO4)3. With the collective interactions of chemical and physical adsorption, the Mo3S13-LDH demonstrates an extremely large iodine adsorption capacity of 1580 mg/g. Under γ radiation, the structure of Mo3S13-LDH well maintains and iodine adsorption capability does not deteriorate, indicating the good irradiation resistance. This work provides an important reference to tailor cost-effective sorbents for trapping iodine from radioactive nuclear wastes.

CBe2 H5 - : Unprecedented 2σ/2π Double Aromaticity and Dynamic Structural Fluxionality in a Planar Tetracoordinate Carbon Cluster.

A 14-electron ternary anionic CBe2 H5 - cluster containing a planar tetracoordinate carbon (ptC) atom is designed herein. Remarkably, it can be stabilized by only two beryllium atoms with both π-acceptor/σ-donor properties and two hydrogen atoms, which means that the conversion from planar methane (transition state) to ptC species (global minimum) requires the substitution of only two hydrogen atoms. Moreover, two ligand H atoms exhibit alternate rotation, giving rise to interesting dynamic fluxionality in this cluster. The electronic structure analysis reveals the flexible bonding positions of ligand H atoms due to C-H localized bonds, highlighting the rotational fluxionality in the cluster, and two CBe2 3c-2e delocalized bonds endow its rare 2σ/2π double aromaticity. Unprecedentedly, the fluxional process exhibits a conversion in the type of bonding (σ bond↔π bond), which is an uncommon fluxional mechanism. The cluster can be seen as an attempt to apply planar hypercoordinate carbon species to molecular motors.

Transition-metal-free four-component reaction of nitriles and disulfides/diselenides.

One-pot synthesis of structurally diverse sulfurized/selenated 4-aminopyrimidines has been reported via t-BuOK/K2S2O8-promoted four-component reaction of mixed nitriles and disulfides/diselenides. Mechanistic studies indicate that the reaction proceeds through radical and ionic pathways, and an alkenyl sulfide serves as a key intermediate.

Engineering and regulating the interfacial stability between Li1.3Al0.3Ti1.7(PO4)3-based solid electrolytes and lithium metal anodes for solid-state lithium batteries.

InCl3@Li1.3Al0.3Ti1.7(PO4)3-F (InCl3@LATP-F) solid electrolyte powders are designed and fabricated by coating a uniform InCl3 layer on the surface of F--doped Li1.3Al0.3Ti1.7(PO4)3 (LATP-F) solid powders via a feasible wet-chemical technique. The assembled Li/InCl3@LATP-F/Li cell can undergo longer cycles of 2500 h at 0.4 mA cm-2 without obvious increases in the overvoltage compared to 1837 h for the Li/LATP-F/Li cell, and the interfacial resistance demonstrates a sharp decrease from 3428 to 436 Ω for the Li/InCl3@LATP-F/Li cell during the first 500 h. Importantly, the assembled LiCoO2/InCl3@LATP-F/Li cell delivers a high discharge specific capacity of 126.4 mAh g-1 with a 95.42% capacity retention ratio after 100 cycles at 0.5 C, and the value easily returns to 112.9 mAh g-1 when the current density is abruptly set back to 0.1 C after different rate cycles. These improved results can be mainly attributed to the fact that the InCl3 layer with a lithiophilic nature can react with lithium metal to form a Li-In alloy, which can guarantee homogeneous lithium ion flux to avoid the accumulation of ions/electrons across the interface and suppress the growth of lithium dendrites. Moreover, the InCl3 layer can prevent direct contact of the LATP-F solid electrolyte and lithium metal to effectively alleviate the reduction reaction of Ti4+ and preserve the structural stability of the composite electrolyte. Therefore, this work may provide an effective strategy to engineer and regulate the interfacial stability between LATP solid electrolytes and lithium metal anodes for LATP-type solid-state lithium batteries.

Engineering amorphous SnO2 nanoparticles integrated into porous N-doped carbon matrix as high-performance anode for lithium-ion batteries.

A facile in-situ preparation strategy is proposed to anchor amorphous SnO2 nanoparticles into the porous N-doped carbon (NC) matrix to fabricate amorphous composite powders (am-SnO2@p-NC), which feature the hierarchically interconnected and well interlaced porous configurations by employing polyvinylpyrrolidone as the soft template. The morphology regulation of the porous structure is precisely realized by adjusting the content of the template and the relationship between structural evolution and electrochemical performance of composite powders is accurately described to explore the optimal template dosage. The results indicate that the am-SnO2@p-NC-50 % composite electrode can deliver the improved lithium storage capacity and cycling performance when the content of the template is controlled at 0.500 g, in which the initial discharge specific capacity is about 1557.6 mAh/g and the reversible value retains at 841.5 mAh/g after 100 cycles at 100 mA/g. Meanwhile, the discharge specific capacity of 869.8 mAh/g is exhibited for the am-SnO2@p-NC-50 % composite electrode after 60 cycles when the current density is recovered from 2000 to 100 mA/g. Moreover, the Li+ ions diffusion coefficient up to about 5.5 × 10-12 cm2/s is calculated from galvanostatic intermittent titration technique tests, which can be partly ascribed to the conductive NC substrate that provides the high electronic conductivity, and partly to the highly porous structure that shortens Li+ ions transfer pathways and guarantees the fast reaction kinetics. Therefore, the hierarchically porous engineering of carbon networks to confine amorphous transition metal oxide nanoparticles is of great significance in the development of high-performance anode materials for lithium-ion batteries.

The dodeca-coordinated La©B8C4 +/0/- molecular wheels: conflicting aromaticity versus double aromaticity.

The transition-metal centered boron molecular wheels have attracted the attention of chemists. The highest deca-coordination number for central metal atoms was observed in D 10h Ta©B10 - and Nb©B10 - molecular wheels. Here, we report a theoretical study of La©B8C4 q (q = +1, 0, -1) clusters with the dodeca-coordinated La atom. The La©B8C4 q clusters adopt fascinating molecular wheel structures, showing a La atom enclosed by a perfect B8C4 monocyclic ring. The cationic La©B8C4 + cluster has a C 4v symmetry with the distinctly out-of-plane distortion of the La atom (0.70 Å), which is gradually flattened by the sequential reduction reaction. The distortion of the La atom from the plane in the neutral La©B8C4 cluster decreases to 0.46 Å. The La©B8C4 - species turns out to be perfectly planar. Chemical bonding analyses indicate that the neutral La©B8C4 and anionic La©B8C4 - possess 10σ and 9π/10π double aromaticity, respectively, obeying the principle of double aromaticity. However, the cationic La©B8C4 + has 10σ and 8π conflicting aromaticity, representing a counterexample in planar hyper-coordinated molecular wheels. The dodeca-coordination number in La©B8C4 q (q = +1, 0, -1) clusters is unprecedented, which provides a new idea and concept for searching planar hyper-coordinated systems.

Understanding the Neural Mechanisms of General Anesthesia from Interaction with Sleep-Wake State: A Decade of Discovery.

The development of cutting-edge techniques to study specific brain regions and neural circuits that regulate sleep-wake brain states and general anesthesia (GA), has increased our understanding of these states that exhibit similar neurophysiologic traits. This review summarizes current knowledge focusing on cell subtypes and neural circuits that control wakefulness, rapid eye movement (REM) sleep, non-REM sleep, and GA. We also review novel insights into their interactions and raise unresolved questions and challenges in this field. Comparisons of the overlapping neural substrates of sleep-wake and GA regulation will help us to understand sleep-wake transitions and how anesthetics cause reversible loss of consciousness. SIGNIFICANCE STATEMENT: General anesthesia (GA), sharing numerous neurophysiologic traits with the process of natural sleep, is administered to millions of surgical patients annually. In the past decade, studies exploring the neural mechanisms underlying sleep-wake and GA have advanced our understanding of their interactions and how anesthetics cause reversible loss of consciousness. Pharmacotherapies targeting the neural substrates associated with sleep-wake and GA regulations have significance for clinical practice in GA and sleep medicine.

Bimetallic metal-organic frameworks-based ratiometric fluorescence sensor for the quantitative detection of thiram in fruits samples.

The identification of residual thiram (Tr) in foods is vital in view of its harmful effects on human health. Herein, a ratiometric fluorescence sensor (I435/I590) based on rhodamine B/NH2-MIL-53(Al0.75Fe0.25) was constructed for the detection of Tr. Interestingly, the probe RhB/NH2-MIL-53(Bim) assisted by Cu2+ could rapidly and sensitively recognize Tr with a low detection limit of 0.11 µg/mL in 10 min. The fluorescence sensing mechanism was investigated using fluorescence spectra, UV-Vis absorption spectra, the fluorescence lifetime and quantum yield. The results showed that the excellent sensing performance was attributed to fluorescence resonance energy transfer, electrostatic interaction, and photoinduced electron transfer. In addition, the practical application of this platform showed acceptable relative recoveries for Tr (84.03-107.81 %), and precisions were also achieved (relative standard deviation ≤ 8.69 %, n = 3). These results show that the presented herein can be applied to monitor the Tr content in real fruit samples.

Revealing the effect of Nb5+ on the electrochemical performance of nickel-rich layered LiNi0.83Co0.11Mn0.06O2 oxide cathode for lithium-ion batteries.

The layered Nb5+-doped LiNi0.83Co0.11Mn0.06O2 (NCM) oxide cathode materials are successfully synthesized through introducing Nb2O5 into the precursor Ni0.83Co0.11Mn0.06(OH)2 during the lithiation process. The results refined by GSAS software present that the Nb5+-doped samples possess the perfect crystal structure with broader Li+ diffusion pathways. Moreover, the morphology characterized by scanning electron microscope displays the compact secondary particles packed by smaller primary particles under the effect of Nb5+. The excellent electrochemical properties are also acquired from the Nb5+-doped samples, in which the optimal rate performance and cycling stability are performed for NCM-1.0 when up to 1.0 mol % of Nb2O5 (based on the precursor) is added. Benefited from the introduction of Nb5+, the cell assembled with the NCM-1.0 electrode retains higher capacity retention of 86.6 % at 1.0 C and 25 °C, and 71.7 % at 1.0 C and 60 °C after 200cycles. Moreover, it also delivers higher discharge specific capacity of 154.6 mAh g-1 at 5.0 C. Therefore, the Nb5+-doping strategy may open an effective route for optimizing nickel-rich oxide cathode materials, which is worth popularizing for the enhancement of the electrochemical performance of nickel-rich cathodes for lithium-ion batteries.

Electrospinning fabrication of Sb-SnSb/TiO2@CNFs composite nanofibers as high-performance anodes for lithium-ion batteries.

The SnSb and TiO2 nanoparticles uniformly embedded into continuous and conductive carbon nanofibers (CNFs) are successfully fabricated through facile electrospinning combined with calcination treatments. The characterization results of the targeted composite nanofibers (Sb-SnSb/TiO2@CNFs-2) confirm that the presence of TiO2 is of significant importance to construct the elaborately designed and intact fiber structure, in which the optimal dosage of the TiO2 precursor is precisely controlled at 2 mmol. Moreover, high theoretical specific capacity of SnSb, available inhibitory effect of TiO2, and great electronic conductivity of CNFs are cooperatively integrated into the Sb-SnSb/TiO2@CNFs-2 composite nanofibers, guaranteeing the enhanced lithium storage capacity and cycling performance when being employed as the anode electrodes. Specifically, the Sb-SnSb/TiO2@CNFs-2 electrode can not only deliver initial discharge specific capacity of 1146.6 mAh/g at 100 mA/g and reversible discharge specific capacity of 580.4 mAh/g after 100 cycles, but also retain discharge specific capacity of 561.3 mAh/g after rate cycles along with recovering the current density to 100 mA/g. Importantly, the Sb-SnSb/TiO2@CNFs-2 electrode is also endowed with prominent advantages in the pseudocapacitive contribution of 66.89 % at 0.8 mV/s. Those investigations and findings of the Sb-SnSb/TiO2@CNFs-2 composite electrodes with facile fabrication process and excellent electrochemical performance can contribute to the practical application of the alloy anodes in the field of the energy storage.

Dexmedetomidine Preserves Activity of Neurons in Primary Somatosensory Cortex Compared to Propofol and Ketamine.

General anesthesia has been shown to induce significant changes in the functional connectivity of the cerebral cortex. However, traditional methods such as electroencephalography (EEG) or functional magnetic resonance imaging (fMRI) lack the spatial resolution to study the effects of general anesthesia on individual cortical neurons. This study aimed to use high-resolution two-photon imaging, which can provide single-neuron resolution, to investigate the characteristics of consciousness under general anesthesia. We used C57BL/6J and Thy1-GCamp6s mice and found that at similar levels of sedation, as measured by EEG, dexmedetomidine did not significantly inhibit the spontaneous activity of neuronal somata in the S1 cortex, but preserved the frequency of calcium events in neuronal spines. In contrast, propofol and ketamine dramatically inhibited the spontaneous activity of both neuronal somata and spines. The S1 cortex still responded to whisker stimulation under dexmedetomidine anesthesia, but not under propofol or ketamine anesthesia. Our results suggest that dexmedetomidine anesthesia has unique neuronal properties associated with its ability to facilitate easy awakening in the clinic. These findings provide insights into the development of more effective strategies for monitoring consciousness during general anesthesia.

Palladium-Catalyzed Ring-Opening Reaction of Cyclopropenones with Vinyl Epoxides.

We report herein the Pd-catalyzed selective ring-opening reaction of cyclopropenones with vinyl epoxides. By using a commercially available Pd2(dba)3·CHCl3-BINAP catalyst, a wide range of conjugated alkadienyl carboxylates could be accessed in good yield and excellent regioselectivity. The new application of zwitterionic π-allyl palladium intermediates has been demonstrated in organic synthesis.

Y©B8C4 cluster: a boron-carbon molecular wheel with dodeca-coordination number in plane.

Computational evidence is reported for the largest planar molecular wheel of the Y©B8C4 cluster, featuring an yttrium atom enclosed by a highly symmetric B8C4 ring. The B8C4 ring is viable in the -(BCB)4- form with double 9π/10σ aromaticity. The centered yttrium atom is dodeca-coordinated with the peripheral B8C4 ring, which sets a record coordination number for a planar structure in chemistry heretofore.

Investigation of W6+-doped in high-nickel LiNi0.83Co0.11Mn0.06O2 cathode materials for high-performance lithium-ion batteries.

WO3 as tungsten dopant is introduced into lithium nickel cobalt manganese (LiNi0.83Co0.11Mn0.06O2, NCM) layered oxide powders to synthesize W6+-doped NCM cathode materials during the lithiation process of the hydroxide precursor. Introducing W6+ into the lattice can lead to the diversities of the crystal structure, surface morphology, and electrochemical performance. The crystal structure confirmed by X-ray diffraction indicates that the W6+-doped oxide powders present a typical R-3m layered structure with larger interplanar distance and cell volume. Also, scanning electron microscope images reveal that the primary particles shrink forming a tighter surface under the effect of W6+, while the specific changes gradually aggravate with increase in the content of W6+ added. The excellent electrochemical stability of W6+-doped samples is observed, as the stable host structure is reinforced by the strong W-O bond. The stable structure does not only inhibit the anisotropic volume change caused by repetitive H2 â‡” H3 phase transitions, but also sustains the integrated structure to impede the formation of microcracks and the appearance of more side reactions. This research provides an effective route on investigating the potential association between electrochemical performance and structure change for W6+-doped strategy.

Individualized positive end-expiratory pressure with and without recruitment maneuvers in obese patients during bariatric surgery.

This study aimed to determine whether regular recruitment maneuvers (RMs) are essential for obese patients (OPs) undergoing elective laparoscopic bariatric surgery (LBS) during intraoperative ventilation with individualized positive end-expiratory pressure (PEEP). Patients were randomly assigned to two arms: the RM + PEEP-EIT arm consisted of individualized PEEP titrated by electrical impedance tomography (EIT) with two regular RMs and the PEEP-EIT arm consisted of individualized PEEP titrated by EIT without additional RMs. For these two arms together, EIT-guided PEEP varied among individuals. The partial pressure of oxygen in arterial blood to fractional inspired oxygen (PaO2 /FiO2 ) ratio in the RM + PEEP-EIT arm was higher than that in the PEEP-EIT arm at 1 h after pneumoperitoneum (p = 0.024) and at the end of surgery (p = 0.035). There was no great difference in the PaO2 /FiO2 ratio between these two arms when measured 5 min prior to postanesthesia care unit (PACU) departure and on postoperative day 1. Compared with the PEEP-EIT arm, patients in the RM + PEEP-EIT arm had significantly higher intraoperative dynamic respiratory system compliance (p < 0.001) but consumed more vasopressors (p = 0.036). Postoperative pulmonary complications occurred in 1 of 29 patients in the RM + PEEP-EIT arm compared with 2 of 31 patients in the PEEP-EIT arm. Regular lung RMs can improve intraoperative oxygenation and respiratory system compliance among OPs undergoing LBS with EIT-guided individual PEEP. However, the improvement might disappear before leaving the PACU, and regular RMs resulted in more vasopressor consumption.