Effects of intravenous nicardipine followed by oral labetalol in combination with nifedipine controlled-release tablet on severe peripartum hypertension.

OBJECTIVES: To investigate the effects of intravenous nicardipine as initial therapy and oral labetalol combined with nifedipine controlled-release tablet as subsequent treatment of severe peripartum hypertension. MATERIAL AND METHODS: Intravenous nicardipine was delivered as the initial treatment, after the target blood pressure (BP) had been achieved, oral labetalol was used to maintain the target BP. If oral labetalol failed to maintain the target BP, oral labetalol combined with nifedipine controlled-release tablet was used. RESULTS: A total number of 131 patients were enrolled. The target BP (BP < 140/90 mmHg) was achieved in all patients within 60 minutes by intravenous nicardipine. After receiving labetalol orally, the target BP was maintained in nine patients. However, in 104 patients, we had to combine oral labetalol and nifedipine controlled-release tablet due to re-elevation of their systolic BP to 140-159 mmHg. In 18 patients, we restarted intravenous nicardipine because their systolic BP re-elevated above 160 mm Hg. Among the 104 patients who received oral labetalol and nifedipine controlled-release tablet, the target BP was achieved and maintained in 96 patients, and eight patients had to restart nicardipine. Of the total number of 26 patients in whom intravenous nicardipine was resumed, the target BP was successfully maintained in 22 patients with oral labetalol combined with nifedipine controlled-release tablet. CONCLUSIONS: Intravenous nicardipine rapidly and safely lowered severe peripartum hypertension. As subsequent therapy, oral labetalol combined with nifedipine controlled-release tablet protocol may be applied to effectively maintain a target BP.

[Serological Characteristics and Clinical Significance of Irregular Antibodies in Pregnant Women].

OBJECTIVE: To understand the serological characteristics of irregular antibodies in pregnant women and explore their clinical significance. METHODS: From January 2017 to March 2022, 151 471 pregnant women in Women and Children's Hospital of Chongqing Medical University were enrolled in this study, microcolumn gel card test was used for irregular antibody screening, and antibody specificity identification was further performed in some antibody-positive subjects. RESULTS: The positive rate of irregular antibody screening in the enrolled pregnant women was 0.91% (1 375/151 471), 0.23% (355/151 471) was detected in the first trimester, 0.05% (71/151 471) in the second trimester, and 0.63% (949/151 471) in the third trimester. The positive rate of irregular antibody screening in the third trimester was significantly higher than that in the first and second trimester, and a significant increase in the number of positive cases was found in the third trimester than that in the second trimester. The analysis of agglutination intensity of 1 375 irregular antibody screening positive results showed that the weakly positive agglutination intensity accounted for 50.11% (689/ 1 375), which was the highest, the suspicious positive was 18.69% (257/1 375), and the positive was 31.20% (429/1 375). The significant difference in distribution of agglutination intensity was not observed between the first trimester group and the second trimester group, however, in the third trimester, the proportion of suspicious positive and weakly positive was lower than the first trimester, while, the proportion of positive was higher than the first trimester, and the difference was statistically significant (P < 0.001). Among the irregular antibody screening positive pregnant women, the proportion of pregnant women with pregnancy number ≥ 2 was significantly higher than that with pregnancy ≤ 1. Among 60 pregnant women who underwent antibody identification, the distributions of the antibodies were as follows: Rh blood group system accounted for 23.33% (14/60), Lewis system 43.33% (26/60), Kidd system 3.33% (2/60), MNS system 16.67% (10/60), P1PK system 1.67% (1/60), autoantibodies 1.67% (1/60), and 4 cases was unable to identify (6.67%, 4/60). Among specific antibodies, the anti-Lea was the most common (30.00%), followed by anti-E (16.67%) and anti-M (16.67%). CONCLUSION: The differences of irregular antibody serological characteristics exist in pregnant women from different regions with different genetic backgrounds, understanding the characteristics of irregular antibody in local pregnant women is of great significance for ensuring transfusion safety in pregnant women and preventing hemolytic disease of newborn.

Features of MR signals of retroplacental basal decidual space and its diagnostic significance.

BACKGROUND: With more pregnant women undergoing cesarean section, the number of women with scarring in the uterus undergoing uterine magnetic resonance (MR) examination in the second and third trimesters following a subsequent pregnancy, has increased. OBJECTIVE: To investigate features of MR signals in retroplacental basal decidual space. METHODS: The MR imaging data of patients with clinically and pathologically confirmed placenta implantation and complete placental abruption were retrospectively analyzed. RESULTS: Patients with high-intensity signals in T2-weighted images (T2WI) of the retroplacental basal decidual space did not suffer placenta implantation after delivery, while high-intensity signals in T2WI of the retroplacental basal decidual space was not observed in patients with different degrees of placenta implantation. CONCLUSION: As the retroplacental basal decidual space is the barrier between the placenta and myometrium, high-intensity signals in T2WI can improve the confidence of MR exclusion diagnostics of placenta implantation, and can be used as exclusion criteria for MR diagnosis of placenta implantation.

Boosting N2 Conversion into NH3 over Ru Catalysts via Modulating the Ru-Promoter Interface.

Promoters are indispensable components of Ru-based catalysts to promote N2 activation in ammonia (NH3) synthesis. The rational addition and regulation of promoters play a critical role in affecting the NH3 synthesis rate. In this work, we report a simple method by altering the loading sequence of Ba and Ru species to modulate the Ru-promoter interface, thus significantly boosting the NH3 synthesis rate. The Ba-Ru/GC BM catalyst via the prior loading of Ba rather than Ru over graphitic carbon (GC) exhibits a high NH3 synthesis rate of 18.7 mmol gcat-1 h-1 at 400 °C and 1 MPa, which is 2.5 times that of the Ru-Ba/GC BM catalyst via the conventional prior loading of Ru rather than Ba on GC. Our studies reveal that the prior loading of Ba benefits the high dispersion of the basic Ba promoter over an electron-withdrawing GC support, and then Ba species serve as structural promoters to stabilize Ru with small particle sizes, which exposes more active sites for N2 activation. Additionally, the intimate Ba and Ru interface enables facile electron donation from Ba to Ru sites, thus accelerating N2 dissociation to realize efficient NH3 synthesis. This work provides a simple approach to modulating the Ru-promoter interface and maximizing promoter utilization to enhance NH3 synthesis performance.

Synthesis of piperidines and pyridine from furfural over a surface single-atom alloy Ru1CoNP catalyst.

The sustainable production of value-added N-heterocycles from available biomass allows to reduce the reliance on fossil resources and creates possibilities for economically and ecologically improved synthesis of fine and bulk chemicals. Herein, we present a unique Ru1CoNP/HAP surface single-atom alloy (SSAA) catalyst, which enables a new type of transformation from the bio-based platform chemical furfural to give N-heterocyclic piperidine. In the presence of NH3 and H2, the desired product is formed under mild conditions with a yield up to 93%. Kinetic studies show that the formation of piperidine proceeds via a series of reaction steps. Initially, in this cascade process, furfural amination to furfurylamine takes place, followed by hydrogenation to tetrahydrofurfurylamine (THFAM) and then ring rearrangement to piperidine. DFT calculations suggest that the Ru1CoNP SSAA structure facilitates the direct ring opening of THFAM resulting in 5-amino-1-pentanol which is quickly converted to piperidine. The value of the presented catalytic strategy is highlighted by the synthesis of an actual drug, alkylated piperidines, and pyridine.

An engineered nanoplatform cascade to relieve extracellular acidity and enhance resistance-free chemotherapy.

Tumor extracellular acidity and chemoresistance are regarded as the main obstacles to achieving optimal chemotherapeutic efficacy in tumor therapy. Herein, a new kind of acid-cascade P-S-Z nanoparticles (NPs) is developed to relieve extracellular acidosis and enhance chemotherapy without causing drug resistance. The P-S-Z NPs selectively accumulate in tumors and then regulate the release of S-Z NPs containing syrosingopine (Syr) and acid-activated prodrug ZMC1-Pt depending on the extracellular acidity. Benefiting from their small size and positive surface charge, S-Z NPs are easily internalized by tumor cells in deep tumor tissue, facilitating the release of Syr to inhibit lactic acid excretion and ultimately enhance cell acidosis. The prolonged intracellular acidosis not only inhibits tumor cell proliferation, but also continuously triggers the activation of ZMC1-Pt prodrug, a platinum-based chemotherapeutic drug that effectively eliminates cancer cells and restores wild-type p53 function to prevent tumor chemoresistance. As a proof of concept, this is a promising strategy to transfer the adverse effect of intracellular acidosis to facilitate chemotherapy. This well-designed delivery system effectively kills tumor cells without causing significant tumor drug resistance, thus opening a new window to treat cancer.

Water-Promoted Carbon-Carbon Bond Cleavage Employing a Reusable Fe Single-Atom Catalyst.

The development of methods for selective cleavage reactions of thermodynamically stable C-C/C=C bonds in a green manner is a challenging research field which is largely unexplored. Herein, we present a heterogeneous Fe-N-C catalyst with highly dispersed iron centers that allows for the oxidative C-C/C=C bond cleavage of amines, secondary alcohols, ketones, and olefins in the presence of air (O2 ) and water (H2 O). Mechanistic studies reveal the presence of water to be essential for the performance of the Fe-N-C system, boosting the product yield from <1 % to >90 %. Combined spectroscopic characterizations and control experiments suggest the singlet 1 O2 and hydroxide species generated from O2 and H2 O, respectively, take selectively part in the C-C bond cleavage. The broad applicability (>40 examples) even for complex drugs as well as high activity, selectivity, and durability under comparably mild conditions highlight this unique catalytic system.

Room-Temperature Chemoselective Hydrogenation of Nitroarene Over Atomic Metal-Nonmetal Catalytic Pair.

Constructing atomic catalytic pair emerges as an attractive strategy to achieve better catalytic performance. Herein, an atomic Ir1 ─P1 /NPG catalyst with asymmetric Ir─N2 P1 sites that delivers superb activity and selectivity for hydrogenation of various functionalized nitrostyrene is reported. In the hydrogenation reaction of 3-nitrostyrene, Ir1 ─P1 /NPG (NPG refers to N, P-codoped graphene) shows a turnover frequency of 1197 h-1 , while the reaction cannot occur over Ir1 /NG (NG refers to N-doped graphene). Compared to Ir1 /NG, the charge density of the Ir site in Ir1 ─P1 /NPG is greatly elevated, which is conducive to H2 dissociation. Moreover, as revealed by density functional theory calculations and poisoning experiments, the P site in Ir1 ─P1 /NPG is found able to bind nitrostyrene, while the neighboring Ir site provides H to reduce the nitro group in chemoselective hydrogenation of nitrostyrene. This work offers a successful example of establishing atomic catalytic pair for driving important chemical reactions, paving the way for the development of more advanced catalysts to further improve the catalytic performance.

Atomic Insights into Synergistic Nitroarene Hydrogenation over Nanodiamond-Supported Pt1 -Fe1 Dual-Single-Atom Catalyst.

Fundamental understanding of the synergistic effect of bimetallic catalysts is of extreme significance in heterogeneous catalysis, but a great challenge lies in the precise construction of uniform dual-metal sites. Here, we develop a novel method for constructing Pt1 -Fe1 /ND dual-single-atom catalyst, by anchoring Pt single atoms on Fe1 -N4 sites decorating a nanodiamond (ND) surface. Using this catalyst, the synergy of nitroarenes selective hydrogenation is revealed. In detail, hydrogen is activated on the Pt1 -Fe1 dual site and the nitro group is strongly adsorbed on the Fe1 site via a vertical configuration for subsequent hydrogenation. Such synergistic effect decreases the activation energy and results in an unprecedented catalytic performance (3.1 s-1 turnover frequency, ca. 100 % selectivity, 24 types of substrates). Our findings advance the applications of dual-single-atom catalysts in selective hydrogenations and open up a new way to explore the nature of synergistic catalysis at the atomic level.

High quantum efficiency of hydrogen production from methanol aqueous solution with PtCu-TiO2 photocatalysts.

Methanol with 12.5 wt% H2 content is widely considered a liquid hydrogen medium. Taking into account water with 11.1 wt% H2 content, H2 synthesis from the mixture of water and methanol is a promising method for on-demand hydrogen production. We demonstrate an atomic-level catalyst design strategy using the synergy between single atoms and nanodots for H2 production. The PtCu-TiO2 sandwich photocatalyst achieves a remarkable H2 formation rate (2,383.9 µmol h-1) with a high apparent quantum efficiency (99.2%). Furthermore, the oxidation product is a high-value chemical formaldehyde with 98.6% selectivity instead of CO2, leading to a nearly zero-carbon-emission process. Detailed investigations indicate a dual role of the copper atoms: an electron acceptor to facilitate photoelectron transfer to Pt, and a hole acceptor for the selective oxidation of methanol to formaldehyde, thus avoiding over-oxidation to CO2. The synergy between Pt nanodots and Cu single atoms together reduces the activation energy of this process to 13.2 kJ mol-1.

Exclusive Co-N4 Sites Confined in Two-dimensional Metal-Organic Layers Enabling Highly Selective CO2 Electroreduction at Industrial-Level Current.

Metal-organic framework catalysts bring new opportunities for CO2 electrocatalysis. Herein, we first conduct density-functional theory calculations and predict that Co-based porphyrin porous organic layers (Co-PPOLs) exhibit good activity for CO2 conversion because of the low *CO adsorption energy at Co-N4 sites, which facilitates *CO desorption and CO formation. Then, we prepare two-dimensional Co-PPOLs with exclusive Co-N4 sites through a facile surfactant-assisted bottom-up method. The ultrathin feature ensures the exposure of catalytic centers. Together with large specific area, high electrical conductivity and CO2 adsorption capability, Co-PPOLs achieve a peak faradaic efficiency for CO production (FECO =94.2 %) at a moderate potential in CO2 electroreduction, accompanied with good stability. Moreover, Co-PPOLs reach an industrial-level current above 200 mA in a membrane electrode assembly reactor, and maintain near-unity CO selectivity (FECO >90 %) over 20 h in CO2 electrolysis.

Highly Selective Transformation of Biomass Derivatives to Valuable Chemicals by Single-Atom Photocatalyst Ni/TiO2.

Selective CC cleavage of the biomass derivative glycerol under mild conditions is recognized as a promising yet challenging synthesis route to produce value-added chemicals. Here, a highly selective catalyst for the transformation of glycerol to the high-value product glycolaldehyde is presented, which is composed of nickel single atoms confined to the surface of titanium dioxide. Driven by light, the catalyst operates under ambient conditions using air as a green oxidant. The optimized catalyst shows a selectivity of over 60% to glycolaldehyde, resulting in 1058 µmol gCat -1  h-1 production rate, and ≈3 times higher turnover number than NiOx -nanoparticle-decorated TiO2 photocatalyst. Diverse operando and in situ spectroscopies unveil the unique function of the Ni single atom, which can significantly promote oxygen adsorption, work as an electron sink, and accelerate the production of superoxide radicals, thereby improving the selectivity toward glycolaldehyde over other by-products.

Modulating the strong metal-support interaction of single-atom catalysts via vicinal structure decoration.

Metal-support interaction predominately determines the electronic structure of metal atoms in single-atom catalysts (SACs), largely affecting their catalytic performance. However, directly tuning the metal-support interaction in oxide supported SACs remains challenging. Here, we report a new strategy to subtly regulate the strong covalent metal-support interaction (CMSI) of Pt/CoFe2O4 SACs by a simple water soaking treatment. Detailed studies reveal that the CMSI is weakened by the bonding of H+, generated from water dissociation, onto the interface of Pt-O-Fe, resulting in reduced charge transfer from metal to support and leading to an increase of C-H bond activation in CH4 combustion by more than 50 folds. This strategy is general and can be extended to other CMSI-existed metal-supported catalysts, providing a powerful tool to modulating the catalytic performance of SACs.

Potential-Driven Restructuring of Cu Single Atoms to Nanoparticles for Boosting the Electrochemical Reduction of Nitrate to Ammonia.

Restructuring is ubiquitous in thermocatalysis and of pivotal importance to identify the real active site, yet it is less explored in electrocatalysis. Herein, by using operando X-ray absorption spectroscopy in conjunction with advanced electron microscopy, we reveal the restructuring of the as-synthesized Cu-N4 single-atom site to the nanoparticles of ∼5 nm during the electrochemical reduction of nitrate to ammonia, a green ammonia production route upon combined with the plasma-assisted oxidation of nitrogen. The reduction of Cu2+ to Cu+ and Cu0 and the subsequent aggregation of Cu0 single atoms is found to occur concurrently with the enhancement of the NH3 production rate, both of them are driven by the applied potential switching from 0.00 to -1.00 V versus RHE. The maximum production rate of ammonia reaches 4.5 mg cm-2 h-1 (12.5 molNH3 gCu-1 h-1) with a Faradaic efficiency of 84.7% at -1.00 V versus RHE, outperforming most of the other Cu catalysts reported previously. After electrolysis, the aggregated Cu nanoparticles are reversibly disintegrated into single atoms and then restored to the Cu-N4 structure upon being exposed to an ambient atmosphere, which masks the potential-induced restructuring during the reaction. The synchronous changes of the Cu0 percentage and the ammonia Faradaic efficiency with the applied potential suggests that the Cu nanoparticles are the genuine active sites for nitrate reduction to ammonia, which is corroborated with both the post-deposited Cu NP catalyst and density functional theory calculations.

Bioinspired copper single-atom nanozyme as a superoxide dismutase-like antioxidant for sepsis treatment.

Sepsis is a systemic inflammatory response syndrome with high morbidity and mortality mediated by infection-caused oxidative stress. Early antioxidant intervention by removing excessively produced reactive oxygen and nitrogen species (RONS) is beneficial to the prevention and treatment of sepsis. However, traditional antioxidants have failed to improve patient outcomes due to insufficient activity and sustainability. Herein, by mimicking the electronic and structural characteristics of natural Cu-only superoxide dismutase (SOD5), a single-atom nanozyme (SAzyme) featuring coordinately unsaturated and atomically dispersed Cu-N4 site was synthesized for effective sepsis treatment. The de novo-designed Cu-SAzyme exhibits a superior SOD-like activity to efficiently eliminate O2 •-, which is the source of multiple RONS, thus blocking the free radical chain reaction and subsequent inflammatory response in the early stage of sepsis. Moreover, the Cu-SAzyme effectively harnessed systemic inflammation and multi-organ injuries in sepsis animal models. These findings indicate that the developed Cu-SAzyme possesses great potential as therapeutic nanomedicines for the treatment of sepsis.

A risk score for early predicting bloodstream infections in febrile obstetric patients: a pilot study.

PURPOSE: Early prediction of bloodstream infections (BSI) among obstetric patients remains to be a challenge for clinicians. The objective of this study was to develop a risk score and assess its discriminative ability in febrile obstetric patients in a maternal intensive care unit (ICU). METHODS: Between May 2015 and August 2020, a total of 497 febrile obstetric patients were categorized into BSI group (n = 276) and Non-BSI group (n = 221) based on the result of blood cultures. White blood cell count, C-reactive protein (CRP), procalcitonin (PCT), time of interval from amniorrhea to fever (IFAF) and maximum body temperature (Tmax) were compared between the two groups. All patients were divided into training set (n = 298) and validation set (n = 199). The risk score was established using univariate and multivariate logistic regression from patients in the training set, and its discriminative ability was tested among patients in the validation set. RESULTS: The levels of neutrophil, CRP, PCT, IFAF and Tmax were significantly higher in BSI group than those in Non-BSI group. PROM, Tmax, neutrophil and CRP acted as independent predictive factors for BSI in the training set. The area under the receiver operating characteristic curve of risk score for early prediction of BSI in the training, validation set and the whole population was 0.829 (95% CI 0.783-0.876), 0.848 (95% CI 0.792-0.903) and 0.838 (95% CI 0.803-0.873), respectively. CONCLUSION: The risk score has a feasible discriminatory ability in early prediction of BSI in febrile obstetric patients.

Phosphorus coordinated Rh single-atom sites on nanodiamond as highly regioselective catalyst for hydroformylation of olefins.

Single-atom Rh catalysts present superior activity relative to homogeneous catalyst in olefins hydroformylation, yet with limited success in regioselectivity control. In the present work, we develop a phosphorus coordinated Rh1 single-atom catalyst with nanodiamond as support. Benefiting from this unique structure, the catalyst exhibits excellent activity and regioselectivity in hydroformylation of arylethylenes with wide substrate generality, i.e., with high conversion (>99%) and high regioselectivity (>90%), which is comparable with the homogeneous counterparts. The coordination interaction between Rh1 and surface phosphorus species is clarified by 31P solid-state NMR and X-ray absorption spectroscopy (XAS). Rh single atoms are firmly anchored over nanodiamond through Rh-P bonds, guaranteeing good stability in the hydroformation of styrene even after six runs. Finally, by using this catalyst, two kinds of pharmaceutical molecules, Ibuprofen and Fendiline, are synthesized efficiently with high yields, demonstrating a new prospect of single-atom catalyst in pharmaceutical synthesis.

Dynamic Behavior of Single-Atom Catalysts in Electrocatalysis: Identification of Cu-N3 as an Active Site for the Oxygen Reduction Reaction.

Atomically dispersed M-N-C (M refers to transition metals) materials represent the most promising catalyst alternatives to the precious metal Pt for the electrochemical reduction of oxygen (ORR), yet the genuine active sites in M-N-C remain elusive. Here, we develop a two-step approach to fabricate Cu-N-C single-atom catalysts with a uniform and well-defined Cu2+-N4 structure that exhibits comparable activity and superior durability in comparison to Pt/C. By combining operando X-ray absorption spectroscopy with theoretical calculations, we unambiguously identify the dynamic evolution of Cu-N4 to Cu-N3 and further to HO-Cu-N2 under ORR working conditions, which concurrently occurs with reduction of Cu2+ to Cu+ and is driven by the applied potential. The increase in the Cu+/Cu2+ ratio with the reduced potential indicates that the low-coordinated Cu+-N3 is the real active site, which is further supported by DFT calculations showing the lower free energy in each elemental step of the ORR on Cu+-N3 than on Cu2+-N4. These findings provide a new understanding of the dynamic electrochemistry on M-N-C catalysts and may guide the design of more efficient low-cost catalysts.

Viral Metagenomics Reveals Diverse Viruses in the Feces Samples of Raccoon Dogs.

Raccoon dogs as an ancient species of Canidae are the host of many viruses, including rabies virus, canine distemper virus, severe acute respiratory syndrome coronavirus, and so on. With the development of raccoon dog breeding in recent years, some viruses which infected poultry or pigs were also detected from raccoon dogs. At present, the fecal virome of raccoon dogs has been rarely studied. Using an unbiased viral metagenomic approach, we investigated the fecal virome in raccoon dogs collected from one farm of Jilin Province, China. Many DNA or RNA viruses identified in those fecal samples were mainly from seven families, including Circoviridae, Smacoviridae, Genomoviridae, Parvoviridae, Picornaviridae, Astroviridae, and Hepeviridae. This study increased our understanding of the fecal virome in raccoon dog and provided valuable information for the monitoring, prevention, and treatment of viral diseases of these animals.

Highly selective and robust single-atom catalyst Ru1/NC for reductive amination of aldehydes/ketones.

Single-atom catalysts (SACs) have emerged as a frontier in heterogeneous catalysis due to the well-defined active site structure and the maximized metal atom utilization. Nevertheless, the robustness of SACs remains a critical concern for practical applications. Herein, we report a highly active, selective and robust Ru SAC which was synthesized by pyrolysis of ruthenium acetylacetonate and N/C precursors at 900 °C in N2 followed by treatment at 800 °C in NH3. The resultant Ru1-N3 structure exhibits moderate capability for hydrogen activation even in excess NH3, which enables the effective modulation between transimination and hydrogenation activity in the reductive amination of aldehydes/ketones towards primary amines. As a consequence, it shows superior amine productivity, unrivalled resistance against CO and sulfur, and unexpectedly high stability under harsh hydrotreating conditions compared to most SACs and nanocatalysts. This SAC strategy will open an avenue towards the rational design of highly selective and robust catalysts for other demanding transformations.