Main Limitation Factor Research Articles

Fibrolamellar carcinoma registry: Opportunities and challenges.

e16384 Background: Fibrolamellar carcinoma (FLC) is a rare form of primary liver cancer which affects young adults and adolescents without underlying liver disease or cirrhosis. The tumors are typically well circumscribed masses characterized pathologically by well differentiated polygonal hepatic cells with eosinophilic and granular cytoplasm surrounded by fibrous bands. DNAJB1 and PRKACA fusion is perceived as a dominant recurrent genetic alteration in FLC. FLC affects patients worldwide and a continued lack of an international database remains a knowledge gap. Further, there remains a poor understanding of FLC etiology, and major unmet need for more effective therapy. Methods: A patient-centered multi time-points, dynamic registry was developed by Memorial Sloan Kettering (MSK) in collaboration with Google and Maven Wave. The effort was supported by the Fibrolamellar Cancer Foundation (FCF). The study was opened worldwide except for the European Union pending the acquisition of the requiredGeneral Data Protection Regulation (GDPR) of data control and processing. The latter were assigned to Trinity College Dublin (TCD); a partner in this study. Participants were required to have a Google account to access the study. Demographic, clinical and response data were collected at baseline and at selected time points (monthly for up to 18 months). The aim of the registry was to provide a longitudinal understanding of the biography and natural history of the disease and outcomes. Results: Between May 2021 and December 2023, the study was broadcasted publicly worldwide through different venues including MSK, FCF, websites and Google engine. Only 14 patients responded. Table 1 summarizes the study sequence and patients’ enrollment. On average, the participants completed 41% of the monthly surveys. Four responders out of 5 patients were female, with a median age of 32 years (range 21-53). Conclusions: The registry provided a unique opportunity to access a broad global community of patients with FLC. Poor participation was key main limiting factor. Barriers include: (1) the presence of competing registries or studies for FLC, (2) technical limitations such as the exclusivity to access the registry to Google account. Follow-up emails may have been received in spam or junk folders, (3) complexities posed by the GDPR in Europe, and (4) patient-related factors including preoccupation with treatments and symptom management of their illness add to the disinterest in or inability to fill the monthly surveys. Unifying efforts and collaborations among caring physicians and scientists, medical centers, foundations, and patient advocacy groups across the world can help overcome the current challenges and accelerate the buildup of resources for research and practice improvement for the rare FLC. [Table: see text]

Effects of Cellulase and Xylanase Addition on Fermentation Quality, Aerobic Stability, and Bacteria Composition of Low Water-Soluble Carbohydrates Oat Silage

Most oat forage has low water-soluble carbohydrates (WSC), which may be the main limited factor for silage fermentation safely, but oat is rich in cellulose and hemicellulose; therefore, we assume that xylanase and cellulase as additives can reduce the content of cellulose and xylan in oat silage, increase the microbial fermentable sugar content, and improve the fermentation quality of the silage. After wilting, oats were treated as follows: (i) distributed water (CK); (ii) silages inoculated with xylanase (X); (iii) silages inoculated with cellulase (C), ensiling for 3 days (early stage of silage) and 60 days (late stage of silage), respectively, after ensiling 60 days for a 5-day aerobic exposure study. The pH, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were significantly reduced by xylanase and cellulase treatment during the late stage of silage, and the concentration of lactic acid, acetic acid, and ammonia nitrogen increased remarkably. The WSC content reached its peak with xylanase treatment during the late stage of silage. The content of crude protein (CP) was not affected by additives but by the silage period; CP and ether extract (EE) significantly increased during the late stage of silage compared to the early stage. After ensiling, the bacterial community showed that xylanase and cellulase treatment increased the relative abundance of lactic acid bacteria. Lactobacillus has a higher relative abundance with cellulase treatment after 60 days of ensiling; this can effectively reduce the pH of silage and ensure long-term, stable storage of silage. Cellulase and xylanase increased bacterial diversity during aerobic exposure and improved the aerobic stability of silage significantly. This study indicated that different additives and silage periods had significant effects on chemical compositions, fermentation quality, and bacterial community; meanwhile, both additives improved the aerobic stability of silage. In summary, when the WSC of oat is low, cellulase and xylanase have good effects as silage additives, and the comprehensive effect of cellulase is more prominent.

Tentative Prediction of Harmful Algal Blooms in Yangtze Estuary

By using spatial autoregressive models, this paper mainly studied the limited factors and spatio-temporal prediction of harmful algal blooms (HAB). The environmental factors of sea surface temperature (SST), dissolved organic matter (DOM) and suspended sediment concentration (SSC) were used to model the chlorophyll a (Cha) distribution and the occurrence of HAB. The results indicated that SST had no significant influence on the growth of phytoplankton in May and June, but higher SST in July and August decreased the frequency of occurrence of HAB. SSC was the main limited factor of HAB, and considerably and positively influenced the algal growth and HAB. HAB in Yangtze estuary was mainly caused by nutrients not DOM. The predicted spatial pattern in July 2010 was more dispersed than the actual clustered pattern. This clustered pattern should be driven by the combined impacts of coastal current, Taiwan Worm current and the northward seasonal.

ORGANIZATIONAL AND TECHNOLOGICAL PROBLEMS OF INTELLIGENT INTERACTION OF ROAD AND SEA TRANSPORT

This article is devoted to the issues and related problems of intelligent interaction of road and sea transport in the organization of multimodal international transportation. Since, today, the bulk of transportation is carried out with the participation of two or more types of vehicles, a multimodal delivery scheme is in most cases the only possible one when sending goods to another country, as well as to achieve an optimal ratio of quality, price and time. However, there is a problem of inconsistency in the technological process, due to the lack of development of the information management system. The article deals with the main problems of vehicle interaction, shortcomings in the process of intellectual interaction of elements of the transportation process, and their impact on the organization of transportation in the context of a conditional enterprise. Insufficient attention is paid to resolving issues of interaction and eliminating the causes of its inefficiency, while any complex system, which is undoubtedly a transport and logistics system, taking into account the requirements and security conditions imposed on it, in order to optimize, automate processes and smoothly organize work and interaction between individual elements of the system, it is necessary to detailed ordering and systematization of operations and actions that occur in the processes of this system. The mainlimiting factor for successful interaction is the lack of an intelligent management model in the organization of the transport process.

Assessment of Nitrogen Management on Sunflower Yield and Its Economic Response in Smallholder Farms in a Semi-Arid Region

Although sunflower production in Tanzania is increasing, smallholder farmers still face a number of constraints that result in poor yields. Lack or inadequate nutrient supply is one of the main factors limiting crop productivity in Tanzania. However, mineral fertilizer is not always easily available and not economically affordable by smallholder farmers. Therefore, the use of animal manure could be a feasible and financially viable alternative, especially in the Dodoma region, where there is abundant livestock production. The aim is to analyze the effects of different animal manure rates on sunflower yield and the economic response of smallholder farms from Dodoma region. The dataset used in this study was obtained from a 2-year in loco survey. Sunflower yields under different animal manure rates were obtained using a process-based biophysical model, and results linked to an economic assessment. Results considering the 2015 and 2045 period showed a positive effect of animal manure application in sunflower yield (866.8 kg ha−1) under manure rate limiting 5000 kg ha−1. The high rates of animal manure showed a decrease on yield providing evidence that water stress becomes the main limit factor for sunflower growth. Taking the economic assessment into account, an animal manure rate of 3000–5000 kg ha−1 is the most appropriate fertilization management under the environmental and social conditions of Dodoma region, providing a profitable financial return to the farmers (283–416 USD ha−1). Therefore, sunflower is an attractive cash crop for Tanzanian farmers when the soil fertilization is properly managed.

Suppression of Modulation Instability Induced Phase Noise in the Long-Haul Phase-Sensitive Optical Time Domain Reflectometry.

Modulation instability (MI) is the main limitation factor of the maximum optical power in long-haul phase-sensitive optical time domain reflectometry (Φ-OTDR), and induces signal fading and serious phase noise. In this paper, a method of coherent seed injection is proposed to suppress the MI-induced phase noise in long-haul Φ-OTDR. The spontaneous MI is suppressed by stimulating induced MI in an optical fiber. The visibility of the signal in Φ-OTDR is enhanced and the phase noise is suppressed significantly. This paper offers an effective method to increase the maximum input power with the MI-induced phase noise suppressed in the long-haul Φ-OTDR system. As a result, the maximum input power and sensing distance can be potentially increased, which is greatly beneficial to the enhancement of the performance of long-haul Φ-OTDR.

Three-dimensional membranes for artificial lungs: Comparison of flow-induced hemolysis.

Membranes based on triply periodic minimal surfaces (TPMS) have proven a superior gas transfer compared to the contemporary hollow fiber membrane (HFM) design in artificial lungs. The improved oxygen transfer is attributed to disrupting the laminar boundary layer adjacent to the membrane surface known as main limiting factor to mass transport. However, it requires experimental proof that this improvement is not at the expense of greater damage to the blood. Hence, the aim of this work is a valid statement regarding the structure-dependent hemolytic behavior of TPMS structures compared to the current HFM design. Hemolysis tests were performed on structure samples of three different kind of TPMS-based designs (Schwarz-P, Schwarz-D and Schoen's Gyroid) in direct comparison to a hollow fiber structure as reference. The results of this study suggest that the difference in hemolysis between TPMS membranes compared to HFMs is small although slightly increased for the TPMS membranes. There is no significant difference between the TPMS structures and the hollow fiber design. Nevertheless, the ratio between the achieved additional oxygen transfer and the additional hemolysis favors the TPMS-based membrane shapes. TPMS-shaped membranes offer a safe way to improve gas transfer in artificial lungs.

Effect of Sustained Administration of Thymol on Its Bioaccessibility and Bioavailability in Rabbits.

Simple SummaryThe purpose of this study was to investigate the bioavailability and metabolic path of thymol, a major constituent of Thymus vulgaris L., in the rabbit organism. Oral bioavailability is a key parameter affecting the efficacy of substances, but it is not surprising that it does not correlate satisfactorily with efficacy. The main limitation factors are rate of absorption, metabolism, and excretion processes. In this work, the thymol metabolic path in the rabbit organism was determined for the first time after its sustained oral administration. We confirm intensive absorption of thymol from the gastrointestinal tract; our results point to metabolism and accumulation in kidney tissue and intensive metabolic and excretion processes in the liver. Some metabolic processes were present also after thymol withdrawal. Thymol as a lipophilic substance was found only in trace amounts in fat and muscle tissue as a consequence of its conversion into hydrophilic metabolite and greater elimination in the rabbit organism. This paper highlights the insufficient knowledge of modes of action of plant compounds in animal organisms.The objective of this study was the detection of thymol in rabbit plasma, tissues, large intestinal content, and faeces. Forty-eight rabbits were divided into control and experimental groups (thymol 250 mg/kg feed). Thymol was administered for 21 days and then withdrawn for 7 days. Concentration of thymol in the intestinal wall (IW) was significantly higher than in plasma (p < 0.05) and liver (p < 0.05); in the kidneys it was significantly higher than in plasma (p < 0.05) and liver (p < 0.05) during thymol addition. Thymol in IW was significantly higher than in plasma also after withdrawal (p < 0.01). Significant correlation (rs = −1.000, p < 0.01) between IW and plasma points to the intensive absorption of thymol from the intestine, while the correlation between plasma and liver (rs = 0.786, p < 0.05) indicates intensive biotransformation and excretion processes in liver. Significant correlation between liver and kidney (rs = 0.738, p < 0.05) confirms the intensive metabolism of thymol in the kidney. During the withdrawal period, thymol was detected above trace amounts only in faeces, and was significantly higher than in the colon during both periods (p < 0.01). Results show intensive biotransformation of thymol in the rabbit organism.

Investigation on the water vapor oxidation of Super304H at 600 ℃

Steam oxidation is the main limited factor for the heat-resistant steel in fossil power plant. Disclosing the oxidation mechanism and kinetics could be helpful for the daily inspection to ensure the safety operation. To investigate the water vapor oxidation behavior of Super304H, the oxidation test was conducted at 600 ℃ for 25, 50, 100, 150 and 200 h in flowing steam. The structure and compositions of the oxide layers were investigated by line-scanning of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). Surface morphology was observed after the oxidation test. The oxide phases were identified by XRD. The results showed that the oxide layer was duplex structure consisted of a Fe3O4 - Fe2O3 outer layer and an inner oxide layer which contained nickel oxide, Cr2O3, and FeCr2O4. As the oxidation time increased, the thickness of the total oxide layer and inner layer both increased. After 100 h oxidation, oxide layer exfoliation occurred and resulted in rapid growth of new oxide layer in the exfoliation region.

Diversity, Incidence and Severity of Mistletoe on Cocoa (&lt;i&gt;Theobroma Cacao&lt;/i&gt;) in Kumba, Meme Division, Southwest Region, Cameroon

Cocoa is an important cash crop grown in about 400,000 ha in Cameroon and its yield remains low in spite of the use of elites’ varieties. Mistletoes are the main production limitation factor. Ecology and diversity of mistletoe are yet to be investigated in some major cocoa production areas of Cameroon. This study aimed to identify the mistletoe species infecting this crop, determine their incidence, severity and distribution, evaluate their possible sources of infection from farmers’ perspectives in the Kumba locality and appropriate management practices for these parasites. A survey was carried out in 2018, whereby samples of mistletoe on 9-17 years old cocoa plants were collected from 30 farms in 10 villages within the Kumba environs. Voucher specimens were taken for identification at the Limbe Botanic Gardens. A total of 7,279 plants were examined randomly in 3 farms per village and data obtained, analyzed using descriptive analysis and ANOVA. Three mistletoe species were identified: <i>Phragmanthera lapathifolia, Phragmanthera batangae, and Tapinanthus globiferus</i>. All the 10 villages surveyed, were infested with either of the parasites with Kake I having the highest incidence of 43.11% and with all the mistletoe species. <i>Phragmanthera lapathifolia</i> the most abundant (21.43%) of the 2,290 plants were infested. ANOVA at (<I>P</I> =.01;.05) showed that the local cocoa variety, Forastero was significantly susceptible than the hybrid, Trinitario. 86.6% of farmers identified birds as the main element of mistletoe dispersal; 93.3%mentioned that pruning of infected branches is best control for mistletoe. This study has established that three mistletoe parasites infest cocoa plantations in Kumba and determined their incidence, severity and distribution. <i>Phragmanthera lapathifolia </i>was the most abundant parasite and birds were most involved in mistletoe dispersal.

Environmental assessment of greenhouse gases' emission in poplar plantation under extreme climate conditions of winter 2019/2020

Global changes, triggered by increased anthropogenic emissions of greenhouse gases, are the main problem of modern ecology. Soil is the main terrestrial reservoir of carbon, in both organic and inorganic forms. Forests are the major asset in carbon cycling and the mitigation of global climate change in the terrestrial ecosystem, because forest ecosystems in a temperate climate area are the major sink of CO2 from the atmosphere. Carbon dioxide emission from the soil is the major component of greenhouse gas emission, as well as the main respiratory flux from most forest ecosystems. In circumstances of changed climate and increased frequency of extreme climate events, soil greenhouse gas emission from forest ecosystems is gaining more and more importance, having in mind that soil temperature is one of the main limitation factors of greenhouse gas emission from the soil. From the results obtained from the experiment it is evident that the unusually warm winter of 2019/20 had as a consequence higher emission of greenhouse gases from all three experimental plots. Differences in emission between plots and between days can be explained by three main factors: soil composition, temperature difference between days of sampling, and soil moisture content. With an increased frequency of extreme climate events, as a consequence of global climate changes, the occurrence of higher winter temperatures is expected to be more frequent in the future, affecting also higher emission of greenhouse gases from the soil.

Challenges to overcome breakdown limitations in lateral β-Ga2O3 MOSFET devices

In this work, the fabrication of high-performance metal-oxide-semiconductor field-effect transistors (MOSFETs) on Si-doped homoepitaxial layers on (100) Mg-doped semi-insulating β-Ga2O3 substrates is demonstrated. Furthermore, the influence of additional gate and source field-plates is analyzed in regards to the breakdown properties of the MOSFET devices. The comparative study reveals comparable transistor performances of devices with and without field-plates showing maximum drain currents, on/off-current ratios and ON-resistances of ~75 mA/mm, 109 and 110 Ω∙mm, respectively. Moreover, both MOSFET structures show comparable breakdown voltages at around 1200 V which equals an average breakdown field strength of 2 MV/cm emphasizing no influence of the field-plates on the breakdown properties. Analysis of the thin film composition by secondary ion mass spectrometry on the processed β-Ga2O3 wafers indicates an increased concentration of silicon dopants at the interface between epitaxial layer and substrate. Our findings suggest that this might be the current main limitation factor in reaching higher breakdown voltages using field-plated β-Ga2O3 MOSFET devices.

Correlation and causation between the intestinal microbiome and male morphotypes in the giant freshwater prawn Macrobrachium rosenbergii

Males of the giant freshwater prawn (GFP), Macrobrachium rosenbergii, have been staged histologically into three morphotypes: small male (SM), orange claw (OC), and blue claw (BC). At present, the social population structure is the main limited factor of yield and profitability in commercial GFP production. The aim of this study is to investigate the relationship between the intestinal microbiota and the three male morphotypes of GFP. In this study, we quantified bacterial communities and abdominal muscle transcriptomes by parallel 16S rRNA gene amplicon sequencing and RNA-Seq in three male morphotypes of GFP. The abundance of bacteria varied significantly with three male morphotypes. Moreover, we identified 6062 differentially expressed genes and found a pattern of gene expression involved in developmental stages from the small male via the orange claw to the blue claw morphotype. Eleven signal transduction pathways classified into environmental information processing were related to the frequency of the different male morphotypes in the prawn population. Furthermore, the correlation analysis identified that p53, AMPK, MO25, and ATG1 gene expressions were positively correlated with the abundance of Candidatus Hepatoplasma and negatively correlated with the Lactococcus and Bacillus population in the giant freshwater prawn. We revealed an intimate linkage between the intestinal microbiome and morphotypic differentiation in the males of GFP. This study also provides a more effective method to manipulate the frequency of the different male morphotypes in the male prawn population.

Advanced Fabrication Techniques of Microengineered Physiological Systems.

The field of organs-on-chips (OOCs) has experienced tremendous growth over the last decade. However, the current main limiting factor for further growth lies in the fabrication techniques utilized to reproducibly create multiscale and multifunctional devices. Conventional methods of photolithography and etching remain less useful to complex geometric conditions with high precision needed to manufacture the devices, while laser-induced methods have become an alternative for higher precision engineering yet remain costly. Meanwhile, soft lithography has become the foundation upon which OOCs are fabricated and newer methods including 3D printing and injection molding show great promise to innovate the way OOCs are fabricated. This review is focused on the advantages and disadvantages associated with the commonly used fabrication techniques applied to these microengineered physiological systems (MPS) and the obstacles that remain in the way of further innovation in the field.

Evaluation of city sustainability using multi-criteria decision-making considering interaction among criteria in Liaoning province China

City sustainability is a complex system affected by economic, social, and environmental dimensions, with the existence of interaction and conflict among factor. However, there is a lack of real methodology on the measurement of interaction. Then, this article presents a method to calculate the interaction among multiple criteria, including static interaction and dynamic trend similarity, and to compute the weigh coefficient of each indicator induced by this interaction. In addition, the applicability of the proposed method is demonstrated by evaluating the sustainability performance of 14 cities in Liaoning province China in the context of the Triple Bottom Line (TBL) framework. Our results show that the sustainable development of 14 cities in Liaoning province experienced dramatically downward and has a crucial condition from 2013 to 2017. Only Dalian, Shenyang, Panjin, Benxi, and Yingkou could be classified as a Good level (Level Ⅱ), and none of cities was an Excellent level (Level Ⅰ). From spatial-temporal perspective, regional disparities of sustainability are demonstrated by spatial distributions of city sustainability. In detail, the comprehensive sustainability and subsystem exhibit a “cold-spot in West” feature. The scores for indicators reveal that the shortage of science expenditure, declining investment in fixed asset, lack of economic growth, and lagging public transportation are the main limit factor faced by most cities. Meanwhile, tertiary industry development, energy efficiency improvement, increase green coverage, and reduce pollutant emissions are primary driving factors for improving sustainability. Comparing with other methods, MCDM considering interaction among criteria is an appropriate method to evaluate city sustainability.

CONTEMPORARY TRENDS IN OUTCOMES AND RESOURCE UTILIZATION IN HEART TRANSPLANT PATIENTS WITH ACUTE MYOCARDIAL INFARCTION

Development of accelerated coronary artery disease in cardiac transplant is one of main limitation factor in long term survival of the transplant recipient. International Classification of Diseases, Ninth Revision codes were used to identify heart transplant patients with acute myocardial

Dynamic within-season irrigation scheduling for maize production in Northwest China: A Method Based on Weather Data Fusion and yield prediction by DSSAT

Current water consumptions are unsustainable in many regions, which requiring more efficient agricultural water management strategies. This study incorporated the DSSAT-CERES-Maize model with a new algorithm for dynamic within-season irrigation scheduling for maize (Zea mays L.) based on trends in daily forecasted yields. Field experiments were undertaken at four arid and semiarid sites in Northwest China, including Changwu (2010 and 2011, rainfed), Yangling (2014 and 2015, irrigated), Jingyang (2015, irrigated), and Shiyanghe (2015, irrigated). Historical 50-year (1968–2017) weather data were available for each site. In daily yield forecasts, weather data before forecast dates were observed from local weather stations, while the unknown data between forecast and harvest dates were supplemented by local 50-year continuous weather series in the same periods. Then 50 maize yields could be obtained on each forecast day, and the median values were calculated as the prediction on that day. As the growing season advanced, historical weather data were gradually replaced by actual weather data. Further, the dynamics of daily forecasted yields were used to schedule irrigation based on a new algorithm. The new algorithm schedule irrigations by considering the feedbacks of maize grain yield to interactions of actual weather, environment, and management. The results showed that forecasted maize yield had considerable uncertainty before tasseling but rapidly converged to the actual yield about one month before harvest. The mean absolute relative errors (MAREs) of daily forecasted yields were 11.7% and 7.3% at Changwu in 2010 and 2011, respectively. Simulated irrigation use efficiency (IUE) for almost all sites and years were improved. The new irrigation scheduling algorithm will help to improve irrigation scheduling in arid and semiarid areas where precipitation is the main limited factor to maize yield.

Energy Band Architecture of a Hierarchical ZnO/Au/CuxO Nanoforest by Mimicking Natural Superhydrophobic Surfaces.

The ZnO/Cu2O heterojunction promises high efficiency in photocurrent conversion and other light-driven processes, but the lattice mismatch between ZnO and Cu2O leads to slow electron transfer and low conversion efficiency. In addition, the stability of Cu2O is still the main challenging and limiting factor for device applications in real environments. CuxO is a mixed semiconductor of CuO and Cu2O, which is a promising alternative to Cu2O in device fabrication due to its better stability and photocatalytic efficiency. In this work, CuxO nanorods were attached to vertically aligned gold-decorated ZnO nanorods, creating a hierarchical ZnO/Au/CuxO nanoforest. In addition, the hierarchical surface shows superhydrophobicity, which can prevent Cu2O degradation by water and oxygen. Femtosecond time-resolved transient absorption spectroscopy was employed to investigate the electron transfer dynamics in the ZnO/Au/CuxO heterojunction. The nanoforest demonstrates enhanced electron mobility, increased lattice match, and higher photocurrent conversion efficiency compared with bare ZnO, CuxO, or ZnO/CuxO.

Mitigation of Fiber Nonlinear Effects in 1.28 Tbps DQPSK Modulated DWDM System

The main limitation factor of high capacity multichannel DWDM (Dense Wavelength Division Multiplexing) systems are fiber nonlinear effects. The optical signal is severely degraded due to fiber nonlinear effects also known as Kerr fiber nonlinearity. Nonlinear effects under investigation are self-phase modulation (SPM) and cross-phase modulation (XPM). There are several methods to compensate these nonlinear distorts, some less or more effective. Nonlinear distort due to SPM and XPM can be effectively mitigated through implementation of optical DQPSK modulation over commonly used intensity modulation known as OOK (On-Off Keying). This paper presents a numerical simulation model of 1.28 Tbps DWDM system with optical DQPSK modulation. We present several scenarios and methods to mitigate fiber nonlinear effects including Fractional Fourier Transform (FrFT). Linear and nonlinear effects are considered together, so we implement the inline FrFT module in the optical domain which causes a time-frequency plane rotation to mitigate combined linear and nonlinear effects. The performance of proposed 1.28 Tbps DQPSK modulated DWDM system is evaluated in term of bit error rate (BER) and Q factor value.

Constructing hierarchical cobalt doped SnO2/carbon cluster as high reversible and high capacity anodes for sodium storage

Problems of low initial Coulombic efficiency and low cycling life are main limitation factors for SnO2-based materials in sodium storage application. Herein, a cobalt-doped SnO2/carbon cluster is prepared via a simple and fast microwave assisted hydrothermal method. It reveals an iconic hierarchical structure including SnO2 nanoparticles and whiskers, to be demonstrated with excellent electrochemical performance in sodium storage application. In details, a high specific capacity of 576 mAh g−1 can be obtained at a current density of 50 mA g−1 after 250 cycles; an impressive rate capacity of 242 mAh g−1 can be obtained even at a high current density of 1600 mA g−1. It is found that the cobalt dopant can inhibit the SnO2 coarsening, increase the overall conductivity and improve the reversibility of conversion reactions of Sn to SnO2. As a result the as-prepared cobalt-doped SnO2/carbon cluster presents a high initial Coulombic efficiency and an enhanced Na+ diffusion rate, corresponding to high specific capacity and excellent rate performance in sodium storage application. This work demonstrated a promising technique to prepared cobalt-doped nanostructured SnO2/carbon nanocomposites with excellent electrochemical performance as anode for sodium storage application.