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1.
Sci Rep ; 9(1): 19766, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31875029

RESUMO

Currently, little is known regarding the value of quantitative parameters derived from the intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) with integrated slice-specific shimming (iShim) sequence in detecting old myocardial infarction and myocardial fibrosis. This study was to investigate the value of IVIM-MRI with iShim sequence in diagnosing old myocardial infarction and fibrosis. Thirty-five patients with both old myocardial infarction and myocardial fibrosis and 12 healthy volunteers were prospectively enrolled to undergo cardiac diffusion-weighted imaging (DWI) using seven b-values (0, 20, 60, 80, 120, 200 and 600 s/mm2). The iShim sequence was used for IVIM data acquisition, and the diffusion parameters, D, D* and f values for IVIM, and conventional apparent diffusion coefficient (ADC) were evaluated on the anterior, posterior and lateral walls of the ventricular septum using the short axis of the heart. Significant differences were found in the D, D* and f values between healthy subjects and patients with old myocardial infarction and myocardial fibrosis (P = 0.000), with the median value of the D and f significantly smaller in the myocardial infarction and fibrosis than in the normal control but the median value of D* significantly greater in the myocardial infarction and fibrosis than in the normal control. In the receiver operating curve analysis, the areas under the curve were 0.939, 0.988 and 0.959 for the D, D* and f values, respectively. The sensitivities and specificities were 84.6% and 94.4% for D, 88.9% and 84.6% for D* and 100% and 93.1% for the f values, respectively. In conclusion, the IVIM-derived parameters (D, D* and f) obtained using the iShim DWI technique showed high capacity in diagnosing old myocardial infarction and myocardial fibrosis by providing diffusion and perfusion information, which may have great importance in future clinical practice.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31756011

RESUMO

High-energy-density Li metal batteries suffer from a short lifespan under practical conditions, such as limited lithium, high loading cathode, and lean electrolytes, owing to the absence of appropriate solid electrolyte interphase (SEI). Herein, a sustainable SEI was designed rationally by combining fluorinated co-solvents with sustained-release additives for practical challenges. The intrinsic uniformity of SEI and the constant supplements of building blocks of SEI jointly afford to sustainable SEI. Specific spatial distributions and abundant heterogeneous grain boundaries of LiF, LiNx Oy , and Li2 O effectively regulate uniformity of Li deposition. In a Li metal battery with an ultrathin Li anode (33 µm), a high-loading LiNi0.5 Co0.2 Mn0.3 O2 cathode (4.4 mAh cm-2 ), and lean electrolytes (6.1 g Ah-1 ), 83 % of initial capacity retains after 150 cycles. A pouch cell (3.5 Ah) demonstrated a specific energy of 340 Wh kg-1 for 60 cycles with lean electrolytes (2.3 g Ah-1 ).

3.
World J Clin Cases ; 7(17): 2450-2462, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31559281

RESUMO

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is widely accepted as an alternative to surgery for management of complications of portal hypertension. TIPS has been used to treat portal vein thrombosis (PVT) in many centers since the 1990s. Although TIPS has good therapeutic effects on the formation of PVT, the effect of PVT on TIPS stenting has rarely been reported. Patients with splenectomy and pericardial devascu-larization have a high incidence of PVT, which can markedly affect TIPS stent patency and increase the risk of recurrent symptoms associated with shunt stenosis or occlusion. AIM: To investigate the incidence of PVT after splenectomy and its influence on the patency rate of TIPS in patients with cirrhosis and portal hypertension. METHODS: Four hundred and eighty-six patients with portal hypertension for refractory ascites and/or variceal bleeding who required TIPS placement between January 2010 and January 2016 were included in this retrospective analysis. Patients without prior splenectomy were defined as group A (n = 289) and those with prior splenectomy as group B (n = 197). The incidence of PVT before TIPS was compared between the two groups. After TIPS placement, primary patency rate was compared using Kaplan-Meier analysis at 3, 6, 9 and 12 mo, and 2 and 3 years. The clinical outcomes were analyzed. RESULTS: Before TIPS procedure, the incidence of PVT in group A was lower than in group B (P = 0.003), and TIPS technical success rate in group A was higher than in group B (P = 0.016). The primary patency rate in group A tended to be higher than in group B at 3, 6, 9 and 12 mo, 2 years and 3 years (P = 0.006, P = 0.011, P = 0.023, P = 0.032, P = 0.037 and P = 0.028, respectively). Recurrence of bleeding and ascites rate in group A was lower than in group B at 3 mo (P ≤ 0.001 and P = 0.001), 6 mo (P = 0.003 and P = 0.005), 9 mo (P = 0.005 and P = 0.012), 12 mo (P = 0.008 and P = 0.024), 2 years (P = 0.011 and P = 0.018) and 3 years (P = 0.016 and P = 0.017), respectively. During 3-years follow-up, the 1-, 2- and 3-year survival rate in group A were higher than in group B (P = 0.008, P = 0.021, P = 0.018, respectively), but there was no difference of the incidence of hepatic encephalopathy (P = 0.527). CONCLUSION: Patients with prior splenectomy have a high incidence of PVT, which potentially increases the risk of recurrent symptoms associated with shunt stenosis or occlusion.

4.
Adv Mater ; 31(37): e1902785, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31379042

RESUMO

Lithium (Li) metal is regarded as a "Holy Grail" electrode for next-generation high-energy-density batteries. However, the electrochemical behavior of the Li anode under a practical working state is poorly understood, leading to a gap in the design strategy and the aim of efficient Li anodes. The electrochemical diagram to reveal failure mechanisms of ultrathin Li in pouch cells is demonstrated. The working mode of the Li metal anode ranging from 1.0 mA cm-2 /1.0 mAh cm-2 (28.0 mA/28.0 mAh) to 10.0 mA cm-2 /10.0 mAh cm-2 (280.0 mA/280.0 mAh) is investigated and divided into three categories: polarization, transition, and short-circuit zones. Powdering and the induced polarization are the main reasons for the failure of the Li electrode at small current density and capacity, while short-circuit occurs with the damage of the separator leading to safety concerns being dominant at large current and capacity. The electrochemical diagram is attributed from the distinctive plating/stripping behaviors of Li metal, accompanied by dendrites thickening and/or lengthening, and heterogeneous distribution of dendrites. A clear understanding in the electrochemical diagram of ultrathin Li is the primary step to rationally design an effective Li electrode and render a Li metal battery with high energy density, long lifespan, and enhanced safety.

5.
J Am Chem Soc ; 141(23): 9422-9429, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31117672

RESUMO

The stability of a battery is strongly dependent on the feature of solid electrolyte interphase (SEI). The electrical double layer forms prior to the formation of SEI at the interface between the Li metal anode and the electrolyte. The fundamental understanding on the regulation of the SEI structure and stability on Li surface through the structure of the electrical double layer is highly necessary for safe batteries. Herein, the interfacial chemistry of the SEI is correlated with the initial Li surface adsorption electrical double layer at the nanoscale through theoretical and experimental analysis. Under the premise of the constant solvation sheath structure of Li+ in bulk electrolyte, a trace amount of lithium nitrate (LiNO3) and copper fluoride (CuF2) were employed in electrolytes to build robust electric double layer structures on a Li metal surface. The distinct results were achieved with the initial competitive adsorption of bis(fluorosulfonyl)imide ion (FSI-), fluoride ion (F-), and nitrate ion (NO3-) in the inner Helmholtz plane. As a result, Cu-NO3- complexes are preferentially adsorbed and reduced to form the SEI. The modified Li metal electrode can achieve an average Coulombic efficiency of 99.5% over 500 cycles, enabling a long lifespan and high capacity retention of practical rechargeable batteries. The as-proposed mechanism bridges the gap between Li+ solvation and the adsorption about the electrode interface formation in a working battery.

6.
Adv Mater ; 31(19): e1808392, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30907487

RESUMO

The lithium (Li) metal anode is confronted by severe interfacial issues that strongly hinder its practical deployment. The unstable interfaces directly induce unfavorable low cycling efficiency, dendritic Li deposition, and even strong safety concerns. An advanced artificial protective layer with single-ion pathways holds great promise for enabling a spatially homogeneous ionic and electric field distribution over Li metal surface, therefore well protecting the Li metal anode during long-term working conditions. Herein, a robust dual-phase artificial interface is constructed, where not only the single-ion-conducting nature, but also high mechanical rigidity and considerable deformability can be fulfilled simultaneously by the rational integration of a garnet Al-doped Li6.75 La3 Zr1.75 Ta0.25 O12 -based bottom layer and a lithiated Nafion top layer. The as-constructed artificial solid electrolyte interphase is demonstrated to significantly stabilize the repeated cell charging/discharging process via regulating a facile Li-ion transport and a compact Li plating behavior, hence contributing to a higher coulombic efficiency and a considerably enhanced cyclability of lithium metal batteries. This work highlights the significance of rational manipulation of the interfacial properties of a working Li metal anode and affords fresh insights into achieving dendrite-free Li deposition behavior in a working battery.

7.
Sci Adv ; 4(11): eaat3446, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30430133

RESUMO

Lithium (Li) metal anodes have attracted considerable interest due to their ultrahigh theoretical gravimetric capacity and very low redox potential. However, the issues of nonuniform lithium deposits (dendritic Li) during cycling are hindering the practical applications of Li metal batteries. Herein, we propose a concept of ion redistributors to eliminate dendrites by redistributing Li ions with Al-doped Li6.75La3Zr1.75Ta0.25O12 (LLZTO) coated polypropylene (PP) separators. The LLZTO with three-dimensional ion channels can act as a redistributor to regulate the movement of Li ions, delivering a uniform Li ion distribution for dendrite-free Li deposition. The standard deviation of ion concentration beneath the LLZTO composite separator is 13 times less than that beneath the routine PP separator. A Coulombic efficiency larger than 98% over 450 cycles is achieved in a Li | Cu cell with the LLZTO-coated separator. This approach enables a high specific capacity of 140 mAh g-1 for LiFePO4 | Li pouch cells and prolonged cycle life span of 800 hours for Li | Li pouch cells, respectively. This strategy is facile and efficient in regulating Li-ion deposition by separator modifications and is a universal method to protect alkali metal anodes in rechargeable batteries.

8.
Medicine (Baltimore) ; 97(36): e11902, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30200075

RESUMO

This study aims to explore the possibility to apply intravoxel incoherent motion-magnetic resonance imaging (IVIM-MRI) in cardiac imaging.Multi-b-value diffusion-weighted imaging (DWI) sequence scanning was performed on 12 healthy volunteers. A double exponential model was adopted, and the b-value sequence was 0, 20, 60, 80, 120, 200, and 600 second/mm. The D-value, D*-value, and f-value of the anterior posterior and lateral walls of the ventricular septum were respectively measured on the short axis section of the heart, the parameters of the myocardium in different blood supply areas in each segment were recorded, and the measured data of these different segments were compared using analysis of variance.Among these 12 healthy volunteers, the D-value, D*-value, and f-value of these 72 segments were not exactly equal, the D-values of the myocardium in the 5th and 11th segment were lower than those in the 2nd, 3rd, 8th, and 9th segments, and the pairwise differences were statistically significant (P < .001). Furthermore, the difference in D-value between the 5th and 11th segments was not statistically significant (P = 1.000). The D*-value and f-value of the myocardium in the 5th and 11th segment were higher than those in the 2nd, 3rd, 8th, and 9th segments, and the pairwise differences were statistically significant (P < .001). Furthermore, the differences in D*-value and f-value between the 5th and 11th segments was not statistically significant (P = .214, .787).The intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) technique can quantitatively reflect the diffusion and blood perfusion status of the myocardium.


Assuntos
Técnicas de Imagem Cardíaca/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Coração/diagnóstico por imagem , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Adulto Jovem
9.
Angew Chem Int Ed Engl ; 57(43): 14055-14059, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30094909

RESUMO

The lithium metal anode is regarded as a promising candidate in next-generation energy storage devices. Lithium nitrate (LiNO3 ) is widely applied as an effective additive in ether electrolyte to increase the interfacial stability in batteries containing lithium metal anodes. However, because of its poor solubility LiNO3 is rarely utilized in the high-voltage window provided by carbonate electrolyte. Dissolution of LiNO3 in carbonate electrolyte is realized through an effective solvation regulation strategy. LiNO3 can be directly dissolved in an ethylene carbonate/diethyl carbonate electrolyte mixture by adding trace amounts of copper fluoride as a dissolution promoter. LiNO3 protects the Li metal anode in a working high-voltage Li metal battery. When a LiNi0.80 Co0.15 Al0.05 O2 cathode is paired with a Li metal anode, an extraordinary capacity retention of 53 % is achieved after 300 cycles (13 % after 200 cycles for LiNO3 -free electrolyte) and a very high average Coulombic efficiency above 99.5 % is achieved at 0.5 C. The solvation chemistry of LiNO3 -containing carbonate electrolyte may sustain high-voltage Li metal anodes operating in corrosive carbonate electrolytes.

10.
J Antibiot (Tokyo) ; 71(8): 731-740, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29691485

RESUMO

Biotransformation of wortmannilactone F (3) using the marine-derived fungus DL1103 generated wortmannilactone M (1), a novel analog of wortmannilactone, which was a reduction product of 3 at the C-3 carbonyl group. The in vitro inhibitory activities of 10 wortmannilactones, including 1, against electron transport enzymes indicated that all the wortmannilactones were selective inhibitors of NADH-fumarate reductase and NADH-rhodoquinone reductase. The structure-activity relationship analysis showed that the relative configuration of C1" and C5", the positions of double bonds, the oxygen atoms in the dihydropyran moiety, and the keto-carbonyl group in the oxabicyclo-[2.2.1]-heptane moiety were important to the inhibitory activity of wortmannilactones. In vivo studies indicated that 3 significantly decreased the number and size of adult worms in Trichinella spiralis-infected mice in a dose-dependent manner. Notable changes in the cuticle and microvilli of T. spiralis were also observed. Our data provided useful information in the research and development of polyketides with dihydropyran and oxabicyclo [2.2.1] heptane moieties as antihelminthics.


Assuntos
Anti-Helmínticos/farmacologia , Complexo de Proteínas da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Macrolídeos/farmacologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Quinona Redutases/antagonistas & inibidores , Trichinella spiralis/efeitos dos fármacos , Triquinelose/tratamento farmacológico , Animais , Modelos Animais de Doenças , Transporte de Elétrons/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Masculino , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Relação Estrutura-Atividade
11.
Folia Neuropathol ; 56(1): 49-57, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29663740

RESUMO

Cerebral ischemia injury seriously endangers human health and its molecular mechanism is still not fully understood. microRNA-223 (miR-223) has been reported to be involved in many physiological functions but the specific role of miRNA-223 in ischemic neuronal injury is still unclear. An oxygen-glucose deprivation and simulated reperfusion (OGD/R) model was constructed here to investigate the possible role miR-223 played in ischemic neuronal injury. The expression of miRNA-223 in the OGD/R model and its effect on cell proliferation were studied by qPCR and CCK8 assay. We observed that miR-223 was significantly over-expressed after OGD/R treatment and it suppressed significantly cortical neurons proliferation. To further study the mechanism involved, we predicted and examined the potential targets of miR-223 by targetscan, qPCR, western blot and luciferase reporter assay. We found that the expression level of type 1 insulin-like growth factor receptor (IGF1R) was negatively associated with the level of miR-223. Furthermore, the relative luciferase activity of pmirGLO-WT was inhibited obviously, while no significant change was observed in the pmirGLO-Mut group, indicating that miR-223 could bind to IGF1R. Similar cell proliferation suppression caused by miR-223 antagomir was observed when IGF1R was silenced. On the contrary, when cortical neurons were co-treated with miR-223 agomir and the cDNA of IGF1R which did not contain 3'- untranslated region, the inhibition caused by miR-223 disappeared. Our results suggested that miR-223 may suppress proliferation of cortical neurons that were treated with OGD/R via inhibiting IGF1R expression.


Assuntos
Isquemia Encefálica/metabolismo , MicroRNAs/metabolismo , Neurônios/metabolismo , Receptores de Somatomedina/metabolismo , Animais , Regulação da Expressão Gênica/fisiologia , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Acidente Vascular Cerebral/metabolismo
12.
Adv Mater ; 30(25): e1707629, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29676037

RESUMO

Lithium metal batteries (such as lithium-sulfur, lithium-air, solid state batteries with lithium metal anode) are highly considered as promising candidates for next-generation energy storage systems. However, the unstable interfaces between lithium anode and electrolyte definitely induce the undesired and uncontrollable growth of lithium dendrites, which results in the short-circuit and thermal runaway of the rechargeable batteries. Herein, a dual-layered film is built on a Li metal anode by the immersion of lithium plates into the fluoroethylene carbonate solvent. The ionic conductive film exhibits a compact dual-layered feature with organic components (ROCO2 Li and ROLi) on the top and abundant inorganic components (Li2 CO3 and LiF) in the bottom. The dual-layered interface can protect the Li metal anode from the corrosion of electrolytes and regulate the uniform deposition of Li to achieve a dendrite-free Li metal anode. This work demonstrates the concept of rational construction of dual-layered structured interfaces for safe rechargeable batteries through facile surface modification of Li metal anodes. This not only is critically helpful to comprehensively understand the functional mechanism of fluoroethylene carbonate but also affords a facile and efficient method to protect Li metal anodes.

13.
Angew Chem Int Ed Engl ; 57(19): 5301-5305, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29465827

RESUMO

Safe and rechargeable lithium metal batteries have been difficult to achieve because of the formation of lithium dendrites. Herein an emerging electrolyte based on a simple solvation strategy is proposed for highly stable lithium metal anodes in both coin and pouch cells. Fluoroethylene carbonate (FEC) and lithium nitrate (LiNO3 ) were concurrently introduced into an electrolyte, thus altering the solvation sheath of lithium ions, and forming a uniform solid electrolyte interphase (SEI), with an abundance of LiF and LiNx Oy on a working lithium metal anode with dendrite-free lithium deposition. Ultrahigh Coulombic efficiency (99.96 %) and long lifespans (1000 cycles) were achieved when the FEC/LiNO3 electrolyte was applied in working batteries. The solvation chemistry of electrolyte was further explored by molecular dynamics simulations and first-principles calculations. This work provides insight into understanding the critical role of the solvation of lithium ions in forming the SEI and delivering an effective route to optimize electrolytes for safe lithium metal batteries.

14.
Angew Chem Int Ed Engl ; 57(3): 734-737, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29178154

RESUMO

Lithium and sodium metal batteries are considered as promising next-generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and evolution of flammable gas. Herein, first-principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and gas evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and gas evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion-solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.

15.
Proc Natl Acad Sci U S A ; 114(42): 11069-11074, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-28973945

RESUMO

Lithium metal is strongly regarded as a promising electrode material in next-generation rechargeable batteries due to its extremely high theoretical specific capacity and lowest reduction potential. However, the safety issue and short lifespan induced by uncontrolled dendrite growth have hindered the practical applications of lithium metal anodes. Hence, we propose a flexible anion-immobilized ceramic-polymer composite electrolyte to inhibit lithium dendrites and construct safe batteries. Anions in the composite electrolyte are tethered by a polymer matrix and ceramic fillers, inducing a uniform distribution of space charges and lithium ions that contributes to a dendrite-free lithium deposition. The dissociation of anions and lithium ions also helps to reduce the polymer crystallinity, rendering stable and fast transportation of lithium ions. Ceramic fillers in the electrolyte extend the electrochemically stable window to as wide as 5.5 V and provide a barrier to short circuiting for realizing safe batteries at elevated temperature. The anion-immobilized electrolyte can be applied in all-solid-state batteries and exhibits a small polarization of 15 mV. Cooperated with LiFePO4 and LiNi0.5Co0.2Mn0.3O2 cathodes, the all-solid-state lithium metal batteries render excellent specific capacities of above 150 mAh⋅g-1 and well withstand mechanical bending. These results reveal a promising opportunity for safe and flexible next-generation lithium metal batteries.

16.
Angew Chem Int Ed Engl ; 56(45): 14207-14211, 2017 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-28868626

RESUMO

The rechargeable lithium metal anode is of utmost importance for high-energy-density batteries. Regulating the deposition/dissolution characteristics of Li metal is critical in both fundamental researches and practical applications. In contrast to gray Li deposits featured with dendritic and mossy morphologies, columnar and uniform Li is herein plated on lithium-fluoride (LiF)-protected copper (Cu) current collectors. The electrochemical properties strongly depended on the microscale morphologies of deposited Li, which were further embodied as macroscale colors. The as-obtained ultrathin and columnar Li anodes contributed to stable cycling in working batteries with a dendrite-free feature. This work deepens the fundamental understanding of the role of LiF in the nucleation/growth of Li and provides emerging approaches to stabilize rechargeable Li metal anodes.

17.
Nat Commun ; 8(1): 336, 2017 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-28839134

RESUMO

Lithium metal has been regarded as the future anode material for high-energy-density rechargeable batteries due to its favorable combination of negative electrochemical potential and high theoretical capacity. However, uncontrolled lithium deposition during lithium plating/stripping results in low Coulombic efficiency and severe safety hazards. Herein, we report that nanodiamonds work as an electrolyte additive to co-deposit with lithium ions and produce dendrite-free lithium deposits. First-principles calculations indicate that lithium prefers to adsorb onto nanodiamond surfaces with a low diffusion energy barrier, leading to uniformly deposited lithium arrays. The uniform lithium deposition morphology renders enhanced electrochemical cycling performance. The nanodiamond-modified electrolyte can lead to a stable cycling of lithium | lithium symmetrical cells up to 150 and 200 h at 2.0 and 1.0 mA cm-2, respectively. The nanodiamond co-deposition can significantly alter the lithium plating behavior, affording a promising route to suppress lithium dendrite growth in lithium metal-based batteries.Lithium metal is an ideal anode material for rechargeable batteries but suffer from the growth of lithium dendrites and low Coulombic efficiency. Here the authors show that nanodiamonds serve as an electrolyte additive to co-deposit with lithium metal and suppress the formation of dendrites.

18.
Angew Chem Int Ed Engl ; 56(27): 7764-7768, 2017 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-28466583

RESUMO

Lithium (Li) metal is the most promising electrode for next-generation rechargeable batteries. However, the challenges induced by Li dendrites on a working Li metal anode hinder the practical applications of Li metal batteries. Herein, nitrogen (N) doped graphene was adopted as the Li plating matrix to regulate Li metal nucleation and suppress dendrite growth. The N-containing functional groups, such as pyridinic and pyrrolic nitrogen in the N-doped graphene, are lithiophilic, which guide the metallic Li nucleation causing the metal to distribute uniformly on the anode surface. As a result, the N-doped graphene modified Li metal anode exhibits a dendrite-free morphology during repeated Li plating and demonstrates a high Coulombic efficiency of 98 % for near 200 cycles.

19.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 26(4): 370-5, 386, 2014 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-25434132

RESUMO

OBJECTIVE: To understand the infection status and variation tendeNcy of Enterobius vermicularis infection among children at national monitoring spots of soil-transmitted nematodosis from 2006 to 2010, and master the epidemic regularity, so as to provide the evidence for making control strategy and evaluating the control effect. METHODS: A total of 22 national monitoring spots of soil-transmitted nematodosis were established according to the National Surveillance Program of Soil-Transmitted Nematodiasis (Trial), and the children aged 3-12 years were examined through adhesive cellophane anal swabs, thenthe infection rates of children with different ages, genders, nationalities and education levels were analyzed. In addition, the advantage, disadvantage, opportunity and threat of the monitoring work were analyzed by SWOT analysis. Results: A total of 17 068 children were examined in 22 monitoring spots from 2006 to 2010, and 1 363 of them were found being infected with E. vermnicularis, the average infection-rate was 7.99%, and the infection rates of male and female children were 7.39% and 8.70%, respectivel; the average infection rates in each year were 10.01%, 9.68%, 7.41%, 6.96% and 6.57%, respectively. From 2006 to 2009, the infection rates of E. vermicularis in children in Fujian Province was the highest, which were 56.15%, 53.42%, 37.82% and 49.53%, respectively, but in 2010, the infection rate in Guangdong Province (46.06%) was the highest. The fur- ther analysis demonstrated that the female children, 3-6 age group, Li nationality and children at kindergarten stage had relatively high infection rates. The SWOT analysis showed that the advantage of E. vermicularis monitoring in China was its wide coverage and continuity, and the disadvantage was the relatively small investment from the government, the opportunity was that the national monitoring Spot could drive the monitoring work at the provincial, county and other levels, and the threat was that the work was paid less and less attention to in recent years. CONCLUSION: Though the infection rate of E. vermicularis in children at national monitoring spots of soil-transmitted nematodosis has been decreased year by year, high-endemic areas still exist, and thus the work on enterobiasis control and prevention still needs to be strengthened.


Assuntos
Enterobíase/epidemiologia , Enterobius/fisiologia , Monitoramento Epidemiológico , Distribuição por Idade , Animais , Criança , Pré-Escolar , China/epidemiologia , Escolaridade , Enterobíase/transmissão , Feminino , Humanos , Masculino , Medição de Risco , Solo/parasitologia
20.
Artigo em Chinês | MEDLINE | ID: mdl-25345152

RESUMO

OBJECTIVE: To understand the status of Ascaris eggs pollution in soil at national monitoring spots of soil-transmitted nematodiasis, so as to provide the evidence for making countermeasures and evaluating the control effect. METHODS: Ten households were selected from each of the 22 national monitoring spots annually according to the National Surveillance Program of Soil-Transmitted Nematodiasis (Trial), and the soil samples from vegetable gardens, toilet periphery, courtyards and kitchens were collected and examined by using the modified floatation test with saturated sodium nitrate. Fertilized or unfertilized eggs as well as live or dead fertilized eggs were discriminated and identified. In addition, a SWOT analysis of monitoring of Ascaris eggs pollution in the soil of rural China was carried out. RESULTS: A total of 1 090 households were monitored in 22 monitoring spots from 2006 to 2010. The total detection rate of Ascaris eggs in the soil was 30.73%, and the detection rates of fertilized, unfertilized and live fertilized eggs were 13.21%, 26.42% and 20.28%, respectively. The total detection rates of Ascaris eggs in the vegetable garden, toilet periphery, courtyard and kitchen were 16.51%, 13.49%, 14.22% and 10.73% respectively. The SWOT analysis demonstrated that the monitoring work had both advantages and disadvantages, and was faced with opportunities as well as threats. CONCLUSION: The pollution status of Ascaris eggs in the soil is still quite severe at some national monitoring spots, and the counter-measures such as implementing hazard-free treatment of stool, improving water supply and sanitation and reforming environment should be taken to protect people from being infected.


Assuntos
Ascaris/fisiologia , Poluição Ambiental/estatística & dados numéricos , Contagem de Ovos de Parasitas , População Rural/estatística & dados numéricos , Solo/parasitologia , Animais , Ascaris/isolamento & purificação , China , Habitação , Humanos
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