Boosting stable lithium deposition via Li3N-Enriched inorganic SEI induced by a polycationic polymer layer.

Lithium (Li) metal is a promising anode material for future high-energy rechargeable batteries due to its remarkable properties. Nevertheless, excess Li in traditional lithium metal anodes (LMAs) reduces the energy density of batteries and increases safety risks. Electrochemical pre-lithiation is an effective technique for regulating the lithium content of the anodes. However, Cu foil or other non-Li based substrates used for pre-lithiation often have inhomogeneous surfaces and high nucleation barrier, leading to uneven tip deposition of lithium metal and fragile SEI. Herein, we have designed an interfacial layer composed of nano-Si particles and cationic polymer (poly (diallyldimethylammonium chloride)) (denoted as Si@PDDA) to induce the formation of Li3N-rich inorganic SEI and regulate the homogeneous plating/stripping of lithium. The uniformly dispersed nano-Si particles can decrease the Li+ nucleation overpotential through alloying reaction with lithium. The surface of Si nano-particles modified by PDDA contains numerous cationic sites, providing an electrostatic shielding layer to seeding the growth of Li metal and inhibiting dendrites formation. More promisingly, PDDA adsorbs electrolyte anions while transporting Li+, significantly accelerating the decomposition kinetics of inorganic salts within the electrolyte. Therefore, a SEI film rich in Li3N was formed on the anodes, ensuring the excellent interfacial stability and electrochemical cycling performance of LMAs. The symmetrical cells exhibit a cycle life of 900 h at 1 mA cm-2. Moreover, the practical full cells operate at a low negative/positive (N/P) capacity ratio (∼3) for over 160 cycles.

Synergistic effect of LixSi/Li3N artificial interface and 3D framework for enabling Dendrite-free, long-life lithium metal anodes.

Lithium metal is highly favored as an ideal anode material in future high-capacity lithium batteries due to its appealing properties. Nevertheless, the implementation of lithium metal batteries (LMBs) is severely plagued by challenges such as instable solid electrolyte interface (SEI), uncontrolled growth of dendrite, and severe volume expansion. Herein, to address the aforementioned issues, an artificial SEI layer is fabricated, which is comprised of LixSi alloy and Li3N. The in-situ generated LixSi/Li3N interface is formed on the carbon fiber (denoted as CF/LixSi/Li3N) through a spontaneous reaction between molten Li and Si3N4. Density functional theory (DFT) calculations reveal that LixSi alloy has low ion diffusion energy barrier, which facilitates the low nucleation overpotential of Li+ and enables homogeneous lithium deposition. Li3N can further promote the rapid Li+ transport due to the excellent Li+ conductivity. In addition, the reserved 3D space effectively mitigates the volume change along cycling procedure. Owing to the synergistic effect of the LixSi/Li3N protective layer and the 3D structure, the composite anode shows higher cycling stability with a lifetime of more than 3000 cycles at 1 mA cm-2. Furthermore, matched with commercial LiFePO4 (LFP) and LiNi5Co2Mn3O2 (NCM523) cathodes, the full cells also exhibit impressive electrochemical properties. This work introduces an ingenious approach for constructing stable lithium metal anodes and effective lithium metal batteries.

Ultrafast oxidative desulfurization of diesel fuel catalyzed by a polyoxometalate-based catalyst immobilized on functionalized Y-SBA-15.

Y-SBA-15 was synthesized by doping yttrium (Y) into SBA-15 using a solvent-free solid-state grinding method, and 1-butyl-3-methylimidazolium phosphomolybdic salt ([Bmim]3PMo12O40, abbreviated as [Bmim]PMoO) was also synthesized. [Bmim]PMoO/Y-SBA-15 was prepared and used for oxidative desulfurization (ODS). The physicochemical characteristics of the catalyst have been characterized by FT-IR, XRD, N2 adsorption-desorption, FESEM, TEM, XPS, contact angle testing, EPR, etc. A lipophilic surface is beneficial for making the catalyst well disperse in an oil phase, and a hydrophilic core can help to store aqueous oxidants. Therefore, the amphiphilic catalyst 25[Bmim]PMoO/10Y-SBA-15 exhibited high catalytic activity in dibenzothiophene (DBT) ODS, and sulfur compounds can be removed completely within 40 min under the following conditions: VOil = 10 mL, mcatalyst = 0.1 g, m[Bmim]PMoO : m[Bmim]PMoO/10Y-SBA-15 = 25%, and O/S = 4 (molar ratio). In addition, the concentration of aromatics exerted little effect on the DBT ODS. Sulfur compounds in real diesel might be reduced to 8 µg g-1. The hydroxyl radical ˙OH and superoxide radical ˙O2- play crucial roles in the ODS reaction, and the ODS reaction mechanism was also proposed.

Assembly of long silver nanowires into highly aligned structure to achieve uniform "Hot Spots" for Surface-enhanced Raman scattering detection.

Silver nanowires (AgNWs) as a promising surface-enhanced Raman spectroscopy (SERS) substrate could be used in the analytical science due to its high sensitivity. However, it is difficult for the randomly-distributed silver nanowires to offer uniform "hot spots" to achieve the SERS signal reproducibility of small molecules detection. Herein, the evaporation-induced aggregation had been used to assemble long silver nanowires into highly aligned structure to achieve uniform "hot spots" for SERS detection. The normal glass slide with well-aligned silver nanowires could act as a high sensitivity and excellent reproducibility SERS substrate to provide a versatile platform for detecting analytes. Rhodamine 6G (R6G) is used to evaluate the sensitivity and reproducibility of these AgNWs SERS substrates. Even the low concentration of the R6G was 10-10 mol/L, the SERS features of R6G could be still observed clearly, and the uniform distribution of enhancement factor (EF) was higher than 0.8 × 104 accounting for about 75 % in the observed mapping area. Moreover, the relative standard deviation (RSD) of SERS intensity at the band of 610 cm-1 was used to estimate the signal reproducibility, and the calculated RSD value of aligned AgNWs substrate was about 3.6%, which was much higher than that of the randomly distributed AgNWs (26.8%) because of the highly aligned structure of silver nanowires with abundant and uniform inherent "hot spots". In addition, potential SERS detection of other small molecule, e.g. melamine was also demonstrated in the micromolar range.

Epidemiologic Features, Radiological Findings andClinical Outcomes of 19 Patients with COVID-19in a Single Center in Beijing, China.

ObjectiveTo describe the epidemiologic, clinical, laboratory, and radiological characteristics and prognoses of COVID-19 confirmed patients in a single center in Beijing, China. Methods The study retrospectively included 19 patients with nucleic acid-confirmed SARS-CoV-2 infection at our hospital from January 20 to March 5, 2020. The final follow-up date was March 14, 2020. The epidemiologic and clinical information was obtained through direct communication with the patients or their family members. Laboratory results retrieved from medical records and radiological images were analyzed both qualitatively by two senior chest radiologists as well as quantitatively via an artificial intelligence software. Results We identified 5 family clusters (13/19, 68.4%) from the study cohort. All cases had good clinical prognoses and were either mild (3/19) or moderate (16/19) clinical types. Fever (15/19, 78.9%) and dry cough (11/19, 57.9%) were common symptoms. Two patients received negative results for more than three consecutive viral nucleic acid tests. The longest interval between an initial CT abnormal finding and a confirmed diagnosis was 30 days. One patient's nucleic acid test turned positive on the follow-up examination after discharge. The presence of radiological abnormalities was non-specific for the diagnosis of COVID-19. Conclusions COVID-19 patients with mild or no clinical symptoms are common in Beijing, China. Radiological abnormalities are mostly non-specific and massive CT examinations for COVID-19 screening should be avoided. Analyses of the contact histories of diagnosed cases in combination with clinical, radiological and laboratory findings are crucial for the early detection of COVID-19. Close monitoring after discharge is also recommended.

In Situ Growth of Oriented Polyaniline Nanorod Arrays on the Graphite Flake for High-Performance Supercapacitors.

Polyaniline with oriented nanorod arrays could provide high surface area and relaxed nanostructure to optimize ion diffusion paths, thus enhancing the performance of the device. In this paper, we designed an all-solid symmetrical supercapacitor with good performance based on polyaniline nanorod arrays in situ-grown on a graphite flake free-standing substrate. The specific capacitance, cycle stability, and energy density of the prepared supercapacitor device were 135 F/g, 75.4% retention after 1500 cycles, and the energy density is 18.75 W h/kg at a power density of 500 W/kg. The good performance of the supercapacitor device was obviously related to the oriented nanorod arrays of polyaniline/graphite flakes. In order to find the application of the prepared supercapacitor device, the tandem device consisting of three single supercapacitor devices connected in series had been used to drive small electronic equipment. The red light-emitting diode and chronograph could be easily driven by the 3-series supercapacitor devices. These results indicated that the prepared supercapacitor device based on the polyaniline/graphite flake electrode had potential applications in energy storage devices.

[Testicular injection of lipopolysaccharide: An effective method for establishing the mouse model of orchitis].

OBJECTIVE: To search for a method of establishing a reliable mouse model of orchitis and investigate the association of orchitis with the activation of the inflammasome. METHODS: We equally randomized 40 adult male KM mice into groups A (sham operation), B (intraperitoneal injection of lipopolysaccharide ï¼»LPSï¼½), C (unilateral testicular injection of glacial acetic acid ï¼»GAAï¼½), and D (unilateral testicular injection of LPS). At 3 weeks after modeling, we measured the sperm concentration and percentage of progressively motile sperm (PMS) in the epididymis by computer-assisted semen analysis, observed the pathological changes in the testis tissue by HE staining, and determined the expressions of the Caspase-1 and interleukin (IL)-1ß proteins by Western blot. RESULTS: The sperm concentration in the epididymis was significantly decreased in groups B (ï¼»25.74 ± 3.19ï¼½ ×106/ml), C (ï¼»17.16 ± 4.41ï¼½ ×106/ml) and D (ï¼»16.92 ± 7.13ï¼½ ×106/ml) as compared with that in group A (ï¼»28.20 ± 1.63ï¼½ ×106/ml) (all P < 0.05), even more significantly in B than in C and D (P < 0.01), and so was PMS in groups B (ï¼»29.57 ± 2.16ï¼½%), C (ï¼»18.10 ± 2.38ï¼½%) and D (ï¼»7.34 ± 1.63ï¼½%) in comparison with group A (ï¼»59.34 ± 1.10ï¼½%) (P < 0.01), even more significantly in B and C than in D (P < 0.01). Light microscopy revealed different degrees of pathological changes in the testis tissue, most significant in group D, followed by C and B. Both the expressions of Caspase-1 and IL-1ß were remarkably up-regulated in groups B, C and D compared with those in group A (P < 0.01), even more markedly in D than in B and C (P < 0.05). CONCLUSIONS: Unilateral testicular injection of LPS is a more efficient method than either unilateral testicular injection of GAA or intraperitoneal injection of LPS for establishing the mouse model of orchitis. Orchitis may be pathologically associated with the activation of the NLRP3 inflammasome.

[Clinical significance of detection of thrombus precursor protein in severe sepsis].

OBJECTIVE: To evaluate the significance of the changes in plasma thrombus precursor protein (TPP) in severe sepsis. METHODS: Enzyme linked immunoadsorbent assay (ELISA) was used in the determination of plasma TPP in 22 patients with severe sepsis group. Prothrombin time (PT), activated partial thromboplastin time(APTT), fibrin(Fib), D-Dimer were also determined and the values were compared with those obtained from 10 patients with infection and 8 healthy normal controls. At the same time, scores of sepsis related organ failure assessment(SOFA), simplified acute physiology score (SAPSII), Marshall criteria were made respectively in patients with severe sepsis on 1,3,5 days after admission to the ICU. Analysis of correlation between TPP and scores was done. RESULTS: (1)The concentration of TPP and positive rate of D-Dimer in severe sepsis were obviously higher than that in the ordinary infection group and normal control group (all P<0.05). But there were no differences in levels of PT, APTT, and Fib among three groups. (2)The concentration of TPP rose continuously in nonsurvivors due to severe sepsis, and it was positively correlated with scores of SOFA, SAPSII, Marshall criteria. CONCLUSION: TPP levels showed a higher specificity and sensitivity in detecting hypercoagulability state in severe than D-Dimer, PT, APTT, Fib assay. It can be used as a diagnostic and prognostic parameter for early hypercoagulability states and outcome of severe sepsis.