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Severe traumatic brain injury (sTBI) is a prominent contributor to both morbidity and mortality in the elderly population. The monitoring of intracranial pressure (ICP) is crucial in the management of sTBI patients. Nevertheless, the appropriate timing for the placement of ICP monitor in elderly sTBI patients remains uncertain. To determine the optimal timing for the placement of ICP monitor in elderly sTBI patients, in this retrospective cohort study, we collected data from elderly patients (> 65 years) who suffered sTBI and received ICP monitors at Tangdu Hospital, The Fourth Military Medical University, between January 2011 and December 2021. To examine the relationship between the time of ICP monitor placement and in-hospital mortality, we conducted a multi-variate-adjusted restricted cubic spline (RCS) analysis. Additionally, logistic regression analysis was applied to further analyze the influencing factors contributing to early or late ICP monitor placements. A total of 283 eligible elderly TBI patients were included in the current analysis. The in-hospital mortality rate was 73 out of 283 (26%). The RCS analysis demonstrated an inverted U-shaped curve in the relationship between the timing of ICP monitor placement and in-hospital mortality. For the elderly sTBI patient cohort, 6 h was identified as the crucial moment for the treatment strategy. In addition, the protective time window for ICP placement was less than 4.92 h for the GCS 3-5 group, and less than 8.26 h for the GCS 6-8 group. However, the clinical benefit of ICP placement decreased gradually over time. The relationship between ICP placement and in-hospital mortality was non-linear, exhibiting an inverted U-shaped curve in elderly patients with sTBI. For elderly patients with sTBI, early (≤ 6 h) ICP placement was associated with reduced in-hospital mortality. The clinical benefit of ICP placement decreased beyond the optimal time window.
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Ruthenium dioxide is the most promising alternative to the prevailing but expensive iridium-based catalysts for the oxygen evolution reaction in proton-exchange membrane water electrolyzers. However, the under-coordinated lattice oxygen of ruthenium dioxide is prone to over-oxidation, and oxygen vacancies are formed at high oxidation potentials under acidic corrosive conditions. Consequently, ruthenium atoms adjacent to oxygen vacancies are oxidized into soluble high-valence derivatives, causing the collapse of the ruthenium dioxide crystal structure and leading to its poor stability. Here, we report an oxyanion protection strategy to prevent the formation of oxygen vacancies on the ruthenium dioxide surface by forming coordination-saturated lattice oxygen. Combining density functional theory calculations, electrochemical measurements, and a suite of operando spectroscopies, we showcase that barium-anchored sulfate can greatly impede ruthenium loss and extend the lifetime of ruthenium-based catalysts during acidic oxygen evolution, while maintaining the activity. This work paves a new way for designing stable and active anode catalysts toward acidic water splitting.
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Metal-organic frameworks (MOFs) possess well-defined, designable structures, holding great potential in enhancing product selectivity for electrochemical CO2 reduction (CO2R) through active site engineering. Here, we report a novel MOF catalyst featuring pyrazolate-stabilized asymmetric Ni/Cu sites, which not only maintains structural stability under harsh electrochemical conditions but also exhibits extraordinarily high ethylene (C2H4) selectivity during CO2R. At a cathode potential of -1.3 V versus RHE, our MOF catalyst, denoted as Cu1Ni-BDP, manifests a C2H4 Faradaic efficiency (FE) of 52.7% with an overall current density of 0.53 A cm-2 in 1.0 M KOH electrolyte, surpassing that on prevailing Cu-based catalysts. More remarkably, the Cu1Ni-BDP MOF exhibits a stable performance with only 4.5% reduction in C2H4 FE during 25 h of CO2 electrolysis. A suite of characterization toolsâsuch as high-resolution transmission electron microscopy, X-ray absorption spectroscopy, operando X-ray diffraction, and infrared spectroscopyâand density functional theory calculations collectively reveal that the cubic pyrazolate-metal coordination structure and the asymmetric Ni-Cu sites in the MOF catalyst synergistically facilitate the stable formation of C2H4 from CO2.
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In the pursuit of long-term stability for oxygen evolution reaction (OER) in seawater, retaining the intrinsic catalytic activity is essential but has remained challenging. Herein, we developed a Nix Cry O electrocatalyst that manifested exceptional OER stability in alkaline condition while improving the activity over time by dynamic self-restructuring. In 1â M KOH, Nix Cry O required overpotentials of only 270 and 320â mV to achieve current densities of 100 and 500â mA cm-2 , respectively, with excellent long-term stability exceeding 475â h at 100â mA cm-2 and 280â h at 500â mA cm-2 . The combination of electrochemical measurements and in situ studies revealed that leaching and redistribution of Cr during the prolonged electrolysis resulted in increased electrochemically active surface area. This eventually enhanced the catalyst porosity and improved OER activity. Nix Cry O was further applied in real seawater from the Red Sea (without purification, 1â M KOH added), envisaging that the dynamically evolving porosity can offset the adverse active site-blocking effect posed by the seawater impurities. Remarkably, Nix Cry O exhibited stable operation for 2000, 275 and 100â h in seawater at 10, 100 and 500â mA cm-2 , respectively. The proposed catalyst and the mechanistic insights represented a step towards realization of non-noble metal-based direct seawater splitting.
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Electrochemical CO2 reduction (CO2R) is an approach to closing the carbon cycle for chemical synthesis. To date, the field has focused on the electrolysis of ambient pressure CO2. However, industrial CO2 is pressurized-in capture, transport and storage-and is often in dissolved form. Here, we find that pressurization to 50 bar steers CO2R pathways toward formate, something seen across widely-employed CO2R catalysts. By developing operando methods compatible with high pressures, including quantitative operando Raman spectroscopy, we link the high formate selectivity to increased CO2 coverage on the cathode surface. The interplay of theory and experiments validates the mechanism, and guides us to functionalize the surface of a Cu cathode with a proton-resistant layer to further the pressure-mediated selectivity effect. This work illustrates the value of industrial CO2 sources as the starting feedstock for sustainable chemical synthesis.
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Objective: Awake craniotomy with intraoperative brain functional mapping effectively reduces the potential risk of neurological deficits in patients with glioma invading the eloquent areas. However, glioma patients frequently present with impaired neurocognitive function. The present study aimed to investigate the neurocognitive and functional outcomes of glioma patients after awake brain mapping and assess the experience of a tertiary neurosurgical center in China over eight years. Methods: This retrospective study included 80 patients who underwent awake brain mapping for gliomas invading the eloquent cortex between January 2013 and December 2021. Clinical and surgical factors, such as the extent of resection (EOR), perioperative Karnofsky Performance Score (KPS), progression-free survival (PFS), and overall survival (OS), were evaluated. We also used the Montreal Cognitive Assessment (MoCA) to assess the neurocognitive status changes. Results: The most frequently observed location of glioma was the frontal lobe (33/80, 41.25%), whereas the tumor primarily invaded the language-related cortex (36/80, 45%). Most patients had supratotal resection (11/80, 13.75%) and total resection (45/80, 56.25%). The median PFS was 43.2 months, and the median OS was 48.9 months in our cohort. The transient (less than seven days) neurological deficit rate was 17.5%, whereas the rate of persistent deficit (lasting for three months) was 15%. At three months of follow-up, most patients (72/80, 90%) had KPS scores > 80. Meanwhile, compared to the preoperative baseline tests, the changes in MoCA scores presented significant improvements at discharge and three months follow-up tests. Conclusion: Awake brain mapping is a feasible and safe method for treating glioma invading the eloquent cortex, with the benefit of minimizing neurological deficits, increasing EOR, and extending survival time. The results of MoCA test indicated that brain mapping plays a critical role in preserving neurocognitive function during tumor resection.
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Objective: To design a multidisciplinary enhanced recovery after surgery (ERAS) protocol for glioma patients undergoing elective craniotomy and evaluate its clinical efficacy and safety after implementation in a tertiary neurosurgical center in China. Methods: ERAS protocol for glioma patients was developed and modified based on the best available evidence. Patients undergoing elective craniotomy for treatment of glioma between September 2019 to May 2021 were enrolled in a randomized clinical trial comparing a conventional neurosurgical perioperative care (control group) to an ERAS protocol (ERAS group). The primary outcome was postoperative hospital length of stay (LOS). Secondary outcomes were 30-day readmission rate, postoperative complications, duration of the drainage tube, time to first oral fluid intake, time to ambulation and functional recovery status. Results: A total of 151 patients were enrolled (ERAS group: n = 80; control group: n = 71). Compared with the control group, postoperative LOS was significantly shorter in the ERAS group (median: 5 days vs. 7 days, p<0.0001). No 30-day readmission or reoperation occurred in either group. The time of first oral intake, urinary catheter removal within 24 h and early ambulation on postoperative day (POD) 1 were earlier and shorter in the ERAS group compared with the control group (p<0.001). No statistical difference was observed between the two groups in terms of surgical- and nonsurgical-related complications. Functional recovery in terms of Karnofsky Performance Status (KPS) scores both at discharge and 30-day follow-up was similar in the two groups. Moreover, no significant difference was found between the two groups in the Hospital Anxiety and Depression Scale (HADS) scores. Conclusion: The implementation of the ERAS protocol for glioma patients offers significant benefits over conventional neurosurgical perioperative management, as it is associated with enhancing postoperative recovery, without additional perioperative complications and risks. Clinical Trial Registration: Chinese Clinical Trial Registry (http://www.chictr.org.cn/showproj.aspx?proj=42016), identifier ChiCTR1900025108.
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The precise regulation for the structural properties of nanomaterials at the atomic scale is an effective strategy to develop high-performance catalysts. Herein, a facile dual-regulation approach was developed to successfully synthesize Ru1Ptn single atom alloy (SAA) with atomic Ru dispersed in Pt nanocrystals. High-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure demonstrated that Ru atoms were dispersed in Pt nanocrystals as single atoms. Impressively, the Ru1Ptn-SAA exhibited an ultrahigh specific activity (23.59 mA cm-2) and mass activity (2.805 mA/µg-PtRu) for methanol oxidation reaction (MOR) and exhibited excellent exchange current density activity (1.992 mA cm-2) and mass activity (4.71 mA/µg-PtRu) for hydrogen oxidation reaction (HOR). Density functional theory calculations revealed that the introduction of Ru atoms greatly reduced the reaction free energy for the decomposition of water molecules, which promoted the removal of CO* in the MOR process and adjusted the Gibbs free energy of hydrogen and hydroxyl adsorption to promote the HOR. Our work provided an effective idea for the development of high performance electrocatalysts.
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The rapid improvement accuracy of the atomic frequency standard puts forward higher requirements for the measurement resolution of the atomic frequency standard comparison system. To overcome the defect that the single zero-crossing point detection is sensitive to noise in the traditional dual mixer time difference measurement method, a digital frequency measurement method is proposed. This method combines sinusoidal beat technology, multi-channel synchronous acquisition technology, and digital frequency measurement technology, and uses differential compensation of system error to realize the precision measurement of atomic frequency standard. The frequency measurement accuracy is less than 2.5 × 10-14 and the noise floor is better than 6.5 × 10-15/τ = 1 s. The system has a high frequency measurement accuracy and a low noise floor, which can realize the precise measurement of a highly stable frequency source.
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Proton exchange membrane water electrolyzer can sustainably and environmentally friendly produce hydrogen. However, it is hindered by the lack of high-performance anode catalysts for oxygen evolution reaction (OER) in acid electrolyte. Herein, IrCuNi deeply concave nanocubes (IrCuNi DCNCs) are successfully synthesized from the selective etching of the facet of cubic nanoparticles, and they significantly boost the OER. The obtained IrCuNi DCNCs show high activity toward OER in the acidic electrolyte, which only requires an overpotential of 273 mV to achieve the OER current density of 10 mA cm-2 at a low Ir loading of 6.0 µgIr cm-2. The precious metal based mass activity is 6.6 A mgIr-1 at 1.53 V, which is 19 times as high as that of pristine Ir. It demonstrates that the outstanding catalytic performance is beneficial from the well-defined multimetal concave nanostructures, which may shed light on the fabrication of efficient water electrolyzers.
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The development of cost-effective hydroxide exchange membrane fuel cells is limited by the lack of high-performance and low-cost anode hydrogen oxidation reaction catalysts. Here we report a Pt-free catalyst Ru7Ni3/C, which exhibits excellent hydrogen oxidation reaction activity in both rotating disk electrode and membrane electrode assembly measurements. The hydrogen oxidation reaction mass activity and specific activity of Ru7Ni3/C, as measured in rotating disk experiments, is about 21 and 25 times that of Pt/C, and 3 and 5 times that of PtRu/C, respectively. The hydroxide exchange membrane fuel cell with Ru7Ni3/C anode can deliver a high peak power density of 2.03 W cm-2 in H2/O2 and 1.23 W cm-2 in H2/air (CO2-free) at 95 °C, surpassing that using PtRu/C anode catalyst, and good durability with less than 5% voltage loss over 100 h of operation. The weakened hydrogen binding of Ru by alloying with Ni and enhanced water adsorption by the presence of surface Ni oxides lead to the high hydrogen oxidation reaction activity of Ru7Ni3/C. By using the Ru7Ni3/C catalyst, the anode cost can be reduced by 85% of the current state-of-the-art PtRu/C, making it highly promising in economical hydroxide exchange membrane fuel cells.
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PURPOSE: Diffuse midline gliomas (DMG) with H3K27M mutations have been identified as a rare distinctive entity with unique genetic features, varied molecular alterations, and poor prognosis. The current study aimed to evaluate the clinical characteristics and profile of molecular markers on patients with a DMG harboring H3K27M mutations, and explore the impact of this genetic makeup on overall survival. METHODS: We retrospectively analyzed 43 consecutive patients diagnosed with a DMG harboring H3K27M mutations (age range 3 to 75 years) and treated in a tertiary institution within China between January 2017 to December 2019. Various clinical and molecular factors were evaluated to assess their prognostic value in this unique patient cohort. RESULTS: The median overall survival (OS) was 12.83 months. Preoperative Karnofsky Performance Score (KPS) and adjuvant radiotherapy were found to be independent clinical parameters influencing the OS by multivariate analysis (p = 0.027 and p < 0.001 respectively). Whereas extent of tumor resection failed to demonstrate statistical significance. For molecular markers, P53 overexpression was identified as a negative prognostic factor for overall survival by multivariate analysis (p = 0.030). CONCLUSION: Low preoperative KPS, absence of radiotherapy and P53 overexpression were identified as predictors of a dismal overall survival in patients with DMG and H3K27M mutations.
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Mesoporous Fe, S, N doped carbon (m-FeSNC) materials have been successfully synthesized by pyrolysis of polymerized o-phenylenediamine using binary initiators. It exhibited high electrocatalytic activity towards oxygen reduction reaction, and zinc-air battery with higher performance has been fabricated using m-FeSNC than using commercial Pt/C.
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The design and synthesis of high-activity earth-abundant material-based electrocatalysts for hydrogen evolution reaction (HER) are of great significance. Here we develop a novel method to prepare a MoP nanoparticle supported on N,P-codoped reduced graphene oxides (MoP/N,P-rGO) by pyrolysis of the self-assembled precursor. Benefiting from the selected components of the assembly, P and N atoms are mixed at the molecular level, which leads to MoP nanoparticles uniformly attaching to the graphene substrate and a certain amount of N and P atoms codoping to graphene. The obtained MoP/N,P-rGO exhibits a good HER performance that only needs an overpotential of 115 mV to achieve a HER current density of 10 mA cm-2. The enhanced HER performance is due to the well-dispersed MoP nanoparticles and the synergistic effect from the doped graphene substrate. It shows that the selected functional components integrated by the self-assembly process are appropriate precursors for the synthesis of high-quality HER electrocatalysts.
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The phase of nanocrystals has a key role in the modulation of catalytic properties. Uniform and well-crystallized nickel phosphide nanocrystals with controlled phases (Ni5 P4 , Ni2 P, and Ni12 P5 ) and narrow size distributions are synthesized by a wet chemical method. The phases of the as-synthesized nickel phosphide nanocrystals are controlled by the P/Ni precursor molar ratio, heating process, and time of reaction. Rarely reported nearly monodisperse 5.6â nm Ni5 P4 nanocrystals are successfully synthesized and show superior hydrogen evolution reaction (HER) activity. Only a low overpotential of 103â mV is required to achieve the HER current of 10â mA cm-2 at a low catalyst loading of 0.12â mg cm-2 . The high HER activity is attributed to the high quality of the as-obtained Ni5 P4 nanocrystals, which have the electronic effect from the Ni5 P4 phase and also high surface area owing to the small particle size. A systematic study of the controlled synthesis of nickel phosphide nanocrystals is shown in this paper, and the HER catalytic activity is improved through the phase- and size-controlled synthesis of nanocrystals.
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The objectives of present study were to investigate the presence of vitamin D receptor (VDR) in testis and epididymis of ram by polymerase chain reaction (PCR), to locate VDR in testis and epididymis by immunohistochemistry and to compare difference of VDR expression between testis and epididymis before and after sexual maturation by Real time-PCR and Western blot. The results showed that VDR exists in the testis and epididymis of ram while VDR protein in testis and epididymis was localized in Leydig cells, spermatogonial stem cells, spermatocytes, Sertoli cells and principal cells. For the adult ram, the amounts of VDR mRNA and VDR protein were less (p < 0.01) in testis than compared with caput, corpus and cauda epididymis. For prepubertal ram, the result showed the same trend (p < 0.01). However, the expression levels of VDR mRNA and VDR protein in caput, corpus, cauda epididymis and testis showed no significant difference (p > 0.05) between adult and prepubertal. In conclusion, VDR exists in testis and epididymis of ram, suggesting 1α,25-(OH)(2)VD(3) may play a role in ram reproduction.