[The preliminary analysis on the characteristics of the cluster for the COVID-19]

Since December 2019, COVID-19, a new emerging infection disease, has spread in 27 countries and regions. The clusters of many cases were reported with the epidemic progresses. We collected currently available information for 377 COVID-19 clusters (1 719 cases), excluded the hospital clusters and Hubei cases, during the period from January 1 to February 20, 2020. There were 297 family clusters (79%), case median was 4; 39 clusters of dining (10%), case median was 5; 23 clusters of shopping malls or supermarkets (6%), case median was 13; 12 clusters of work units (3%), case median was 6, and 6 clusters of transportation. We selected 325 cases to estimate the incubation period and its range was 1 to 20 days, median was 7 days, and mode was 4 days. The analysis of the epidemic situation in a department store in China indicated that there was a possibility of patients as the source of infection during the incubation period of the epidemic. From February 5 to 21, 2020, 634 persons were infected on the Diamond Princess Liner. All persons are susceptible to the 2019 coronavirus. Age, patients during the incubation period and the worse environment might be the cause of the cases rising. The progress of the two typical outbreaks clearly demonstrated the spread of the early cases in Wuhan. In conclusion, screening and isolating close contacts remained essential other than clinical treatment during the epidemic. Especially for the healthy people in the epidemic area, isolation was the key.

Boosted electrochemical ammonia synthesis by high-percentage metallic transition metal dichalcogenide quantum dots

The electrochemical method can directly convert N2 into the high-value-added NH3 under ambient conditions and is considered to be a green and sustainable alternative to the traditional Haber-Bosch process. However, the electrochemical nitrogen reduction reaction (NRR) suffers from a low ammonia yield rate over the reported electrocatalysts. Herein, we have developed a general strategy to boost the NRR performance, enabled by the metallic 1T phase dominated transition metal dichalcogenide quantum dots (TMD QDs). Impressively, the obtained MoSe2 QDs achieved a superior ammonia yield rate of 340 μg mg-1 cat. h-1 with excellent ammonia generation sustainability. Experimental and theoretical studies revealed that the excellent catalytic activity of MoSe2 QDs mainly originates from the ultra-small quantized size (high surface area and high-density active edge/defect sites) and high-percentage metallic 1T phase (the N2 adsorption on the 1T phase is spontaneous, and the energy barrier of the potential determining step on the 1T phase is very low). Most importantly, our concept is universal for TMD materials (i.e., MoS2, WSe2, WS2 and NbSe2) that also exhibit a much-enhanced ammonia yield rate as compared to other electrocatalysts.

Morphological and Electronic Dual Regulation of Cobalt-Nickel Bimetal Phosphide Heterostructures Inducing High Water-Splitting Performance

Electrocatalytic water splitting (EWS) is a key technology for generating clean and sustainable hydrogen, which can store abundant energy but is impeded by the insufficient efficiency of the anode and cathode catalyst. Designing and constructing non-noble metal composite bifunctional electrocatalysts for promoting both the cathodic hydrogen evolution (HER) and anodic oxygen evolution reactions (OER) is clearly of great importance for EWS. Thus, the chemical composition and morphology of cobalt-nickel bimetal phosphide (Ni, Co)₂P nanoparticles (NPs) encapsulated in nitrogen-doped carbon nanotube hollow microspheres (NCNHMs) can regulate the redox-active sites and enhance the electron transfer, resulting in superior splitting efficiency. Contributing to the synergistic effects between highly active Co-Ni bimetal phosphide NPs and NCNHMs, the obtained Co-Ni bimetal phosphide/NCNHMs display remarkable electrochemical performance for water splitting compared with Ni₂P/NCNHMs. Therefore, the Ni_1.4Co_0.6P/NCNHMs catalysts achieved through a nitriding-phosphidation strategy derived from a hollow Ni_1.4-Co_0.6-based metal organic framework (MOF) exhibit superior HER catalytic activity (87.9 mV at 10 mA cm^-2 tested in 0.5 M H₂SO₄ and 64.4 mV at 10 mA cm^-2 tested in 1 M KOH) and OER catalytic activity (320.0 mV at 10 mA cm^-2 tested in 1 M KOH). The Ni_1.4Co_0.6P/NCNHMs deliver excellent water-splitting catalytic activity (1.55 V at 10 mA cm^-2 tested in 1 M KOH), which is competitive with that of current non-noble metal electrocatalysts. Density functional theory (DFT) simulations and related experimental results suggest that the electron transfer from Co doping and coating with NCNHMs improves the electronic states, which would enhance the binding strength with H-bonds and then promote the electrocatalytic activity.

[Cloning and sequence analysis of leptin receptor overlapping transcript-like 1 gene from Dermatophagoides farinae]

OBJECTIVE

To obtain the leptin receptor overlapping transcript-like 1 encoding gene (LepROTL1 gene) from Dermatophagoides farina, investigate the molecular characteristics of the gene and construct a prokaryotic expression vector to express this gene.

METHODS

The LepROTL1 gene-encoding sequence fragments were captured based on the transcriptome sequencing results, and the full-length gene fragments were amplified from total RNA of D. farinae using a RT-PCR assay, and used to construct the expression plasmid pET28a(+)-LepROTL1, followed by sequencing. The plasmid was transformed into E. coli BL21 (DE3) T1R for the induction of IPTG expression. The expression product was characterized by SDS-PAGE and Western blotting. Bioinformatics analyses were performed to analyze the sequence and the molecular characteristics of its encoded protein.

RESULTS

The amplification products of the RT-PCR assay showed a clear band on agarose gel electrophoresis, and sequencing analysis of the pET28a(+)-LepROTL1 plasmid showed 417 bp in length of the coding gene from the start codon ATG to the termination codon TAA. Following the plasmid transformation into E. coli and induction with IPTG, a specific band was seen on SDS-PAGE, indicating successful expression. Bioinformatics analysis showed that the LepROTL1 gene-encoded protein was composed of 134 amino acids, and had a relative molecular weight of 14 378.13 Da, a hydrophilicity index of 1.149, and certain hydrophobicity. The secondary structure was composed of alpha-helix (19 aa, 14.18%), extended strand (48 aa, 35.82%) and random coil (67 aa, 50.00%). The deduced amino acid sequence was used to obtain homologous genes by BLAST, and the phylogenetic tree showed that D. farinae was clustered with D. pteronyssinus.

CONCLUSIONS

The full-length sequences and expression plasmid of the LepROTL1 gene are obtained, and the molecular features of the gene are demonstrated using bioinformatics analyses, which provide insights into further studies on the gene.

Undercooling-directed NaCl crystallization: an approach towards nanocavity-linked graphene networks for fast lithium and sodium storage

Despite the crystallization of inorganic salt is being technologically related to the fabrication of salt-templated materials, the two key steps, nucleation and crystal growth, still lack the kinetic control to enable precise design of salt scaffolds. Here, we study how the undercooling degree controls the construction of salt scaffolds by kinetically manipulating the nucleation and growth rates in a NaCl-F127-rhodanine system. An effective approach based on undercooling-directed NaCl crystallization is further proposed to tailor the morphology and structure of the carbon materials. Under different undercooling conditions (liquid nitrogen, -55 °C and -25 °C freezing), the salt scaffold can be tuned as spheroidal particles, ellipsoidal nanocrystal aggregates and cubic nanocrystals with round corners, respectively. Correspondingly, hollow carbon nanospheres, nanocavity-linked graphene networks (CGN) and graphene nanosheets (GNS) can be fabricated through a salt template method, respectively. The Li⁺ and Na⁺ storage mechanisms of 3D CGN and 2D GNS are discussed, focusing on the ion diffusion kinetics. The enhanced Li⁺ diffusion kinetics in the 3D interconnected network endows CGN with better rate performance than GNS as lithium-ion battery anode material, and Na⁺ adsorption dominates the Na⁺ storage in CGN as sodium-ion battery anode material. Our findings provide a general idea for the construction crystallization-induced architectures and offer valuable insights to achieve fast Li⁺/Na⁺ storage by boosting the ion diffusion kinetics.

Controllable Synthesis of Two-Dimensional Molybdenum Disulfide (MoS2 ) for Energy-Storage Applications

Lamellar molybdenum disulfide (MoS₂ ) has attracted a wide range of research interests in recent years because of its two-dimensional layered structure, ultrathin thickness, large interlayer distance, adjustable band gap, and capability to form different crystal structures. These special characteristics and high anisotropy have made MoS₂ widely applicable in energy storage and harvesting. In this Minireview, a systematic and comprehensive introduction to MoS₂ , as well as its composites, is presented. It is aimed to summarize the various synthetic methods of MoS₂ -based composites and their application in energy-storage devices (lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, and supercapacitors) in detail. Based on recent studies, this Minireview provides important and comprehensive guidelines for further study and development efforts in the MoS₂ in energy-storage field.

Rechargeable Aqueous Zinc-Ion Batteries in MgSO4/ZnSO4 Hybrid Electrolytes

MgSO₄ is chosen as an additive to address the capacity fading issue in the rechargeable zinc-ion battery system of Mg_xV₂O₅·nH₂O//ZnSO₄//zinc. Electrolytes with different concentration ratios of ZnSO₄ and MgSO₄ are investigated. The batteries measured in the 1 M ZnSO₄^-1 M MgSO₄ electrolyte outplay other competitors, which deliver a high specific capacity of 374 mAh g^-1 at a current density of 100 mA g^-1 and exhibit a competitive rate performance with the reversible capacity of 175 mAh g^-1 at 5 A g^-1. This study provides a promising route to improve the performance of vanadium-based cathodes for aqueous zinc-ion batteries with electrolyte optimization in cost-effective electrolytes.

Enhanced sodium storage kinetics by volume regulation and surface engineering via rationally designed hierarchical porous FeP@C/rGO

Transition metal phosphides, such as iron phosphide (FeP), have been considered as promising anode candidates for high-performance sodium ion batteries (SIBs) owing to their high theoretical capacity. However, the development of FeP is limited by large volume change, low electrical conductivity and sluggish kinetics with sodium ions. Moreover, the sodium storage kinetics and dynamics behavior in FeP are still unclear. Herein, improved sodium storage ability of FeP is achieved by volume regulation and surface engineering via a rationally designed hierarchical porous FeP@C/rGO nanocomposite. This FeP@C/rGO nanocomposite exhibits excellent rate capability and long cycle life as the anode of SIBs. Specifically, the FeP@C/rGO nanocomposite delivers high specific capacities of 635.7 and 343.1 mA h g-1 at 20 and 2000 mA g-1, respectively, and stable cycling with 88.2% capacity retention after 1000 cycles. The kinetics and dynamics studies demonstrate that the superior performance is attributed to the rationally designed hierarchical porous FeP@C/rGO with a high capacitive contribution of 93.9% (at 2 mV s-1) and a small volume expansion of only 54.9% by in situ transmission electron microscopy (TEM) measurement. This work provides valuable insights into understanding the phase evolution of FeP during the sodiation/desodiation process for designing high-performance SIBs.

Capacitive Deionization of Divalent Cations for Water Softening Using Functionalized Carbon Electrodes

Water softening is a relatively untapped area of research in capacitive deionization (CDI). In this work, we demonstrate how an asymmetric combination of oxidized and aminated carbon can be used for selective removal of divalent cations for water softening. We first show how higher electrosorption performances can be achieved in single-salt experiments involving NaCl, KCl, MgCl2, and CaCl2 before proceeding to multi-salt experiments using different combinations of the four salts. The salt combinations are chosen to investigate one of the three factors: (1) ionic mass, (2) ionic charge, or (3) concentration. We show how divalent selectivity can be achieved due to high local electrostatic attraction between negatively charged oxygen moieties and divalent cations. Additionally, an ion-exchange process between the oxidized carbon surface and cations can result in lower pH values, which prevent the precipitation of scale-forming ions.

Microstructural Engineering of Cathode Materials for Advanced Zinc-Ion Aqueous Batteries

Zinc-ion batteries (ZIBs) have attracted intensive attention due to the low cost, high safety, and abundant resources. However, up to date, challenges still exist in searching for cathode materials with high working potential, excellent electrochemical activity, and good structural stability. To address these challenges, microstructure engineering has been widely investigated to modulate the physical properties of cathode materials, and thus boosts the electrochemical performances of ZIBs. Here, the recent research efforts on the microstructural engineering of various ZIB cathode materials are mainly focused upon, including composition and crystal structure selection, crystal defect engineering, interlayer engineering, and morphology design. The dependency of cathode performance on aqueous electrolyte for ZIB is further discussed. Finally, future perspectives and challenges on microstructure engineering of cathode materials for ZIBs are provided. It is aimed to provide a deep understanding of the microstructure engineering effect on Zn2+ storage performance.

[Long-term efficacy analysis of laparoscopic-assisted anorectoplasty for high and middle imperforate anus]

Objective: To explore the long-term efficacy of laparoscopic-assisted anorectoplasty and conventional anorectoplasty in the treatment of children with high and middle anal atresia. Methods: A retrospective cohort study was used. Inclusion criteria: (1) children with high and middle anal atresia; (2) complicated with rectourethral or rectovesical fistula; (3) complete follow-up data. Exclusion criteria: (1) complicated with 21-trisomy; (2) cerebral palsy and other mentaldisabilities; (3) Currarino syndrome; (4) FG syndrome. Clinical data of 88 patients with middle and high anal atresia, who complicated with rectourethral fistula or rectovesical fistula, and underwent anoplasty at Department of Pediatric Surgery, the First Affiliated Hospital of Zhengzhou University from January 2009 to June 2014 were enrolled in the study and analyzed. There were 24 cases with middle atresia and 64 cases with high atresia. All the cases were divided into 2 groups based on the operative method: laparoscopic group (laparoscopic-assisted anorectoplasty, 49 cases), pena group (posterior sagittal anorectoplasty, 39 cases). The demographic features of two groups were comparable. There were no statistically significant differences in gender, age, body mass, classification of anomaly types and sacral ratio (all P>0.05). Student t test and Chi square tests were used to compare the surgical conditions (operative time, postoperative hospital stay and complications), anal function (Kelly score), constipation (Krickenbeck constipation score) and anorectal pressure. Results: Children of both groups all completed operation ssuccessfully. There were no statistically significant differences between laparoscopic group and pena group in the operative time [(120±31) minutes vs. (112±23) minutes, t=1.343, P=0.091] and postoperative hospital stay [(7.1±2.3) days vs. (10.7±3.3) days, t=6.021, P=1.000]. Complications were more common in the pena group [16.3% (8/49) vs. 35.9% (14/39), χ(2)=4.436, P=0.035]. The main complications in laparoscopic group were anal prolapse (8.2%, 4/49) and anal stenosis (6.2%, 3/49), while in pena group were anal stenosis (12.8%, 5/39) and perioperative perianal skin erosion (10.3%, 4/39). As for the anal function, the degree of feces, defecation control and sphincter contractility, the single scoring differences of Kelly scoring system were not statistically significant between the two groups, but the proportion of good function in the laparoscopic group was higher than that in the pena group [67.3% (8/49) vs. 38.5% (15/39), χ(2)=7.308, P=0.007]. Constipation occurred in 6 (12.2%) patients in the laparoscopic group, of whom 5 were improved by diet regulation and 1 required laxatives, while 9 (23.1%) patients developed constipation in the pena group, of whom 4 were improved by diet regulation and 5 required long-term laxatives. The difference of constipation ratio was not statistically significant (χ(2)=1.802, P=0.180). There were no cases of Krickenbeck constipation grade 3. Compared to the pena group, the laparoscopic group had higher anal resting pressure [(33.35±9.69) mmHg vs. (27.68±10.74) mmHg, t=2.599, P=0.011], higher dilating pressure [(9.00±5.61) mmHg vs.(6.51±3.24) mmHg, t=2.462, P=0.016], higher maximal squeeze pressure [(65.80±17.23) mmHg vs. (56.74±18.93) mmHg, t=2.389, P=0.019] and longer maximal contraction time [(21.16±5.02) seconds vs. (18.44±7.24) seconds, t=2.079, P=0.041]. The rectal resting pressure [(5.36±3.00) mmHg vs. (4.61±3.93) mmHg, t=1.015, P=0.312] was not statistically significantly different. Conclusions: Compared with posterior sagittal anorectoplasty, laparoscopic-assisted anorectoplasty in the treatment of high and middle anal atresia has better long-term efficacy with less perioperative complications.

[Clinical study on topography-guided laser ablation combined with accelerated corneal collagen cross-linking for early keratoconus]

Objective: To study the safety and efficacy of topography-guided customized excimer laser subepithelial ablation combined with accelerated collagen cross-linking technique in treatment of early keratoconus. Methods: Ninteen patients(20 eyes) (13 males 14 eyes, and 6 females 6 eyes), aged 12 to 44 years (24.7±8.0) were diagnosed as keratoconus by three-dimensional corneal topography and tomography, clinical history and examinations, and classified as KC1~KC3. Based on the classical excimer laser subepithelial keratomileusis (LASEK) method, topography guided laser ablation was performed with an excimer laser system (WaveLight EX500). After laser ablation, the corneal stromal bed was immersed with 0.1% riboflavin for 10 minutes, and then was irradiated by ultraviolet light (Avedro KXL) at 30 mW/cm(2) for 4 minutes. All the patients were followed up for more than 12 months. The uncorrected visual acuity (UCVA), diopter, best corrected visual acuity (BSCVA), corneal topography, central corneal endothelial cell density (ECD), hexagonal cell percentage (HEX), coefficient of variation (CV) and other indicators were observed. For normal distribution variables, Dunnett-t test was used before and after operation, and Wilcoxon test was used for variables with abnormal distribution. And the complications were recorded. Results: There was no loss of BSCVA at 12 months postoperatively, 20% of the eyes had no change of BSCVA, and 15% of the eyes gained 1 line of BSCVA, 15% of the eyes gained 2 lines of BSCVA, 50% of the eyes gained 3 lines and more of BSCVA. There was no significant difference in UCVA, BSCVA, manifest refractive spherical equivalent (MRSE) and the cylinder at 3 months postoperatively (P>0.05). The BSCVA were significantly improved at 6 and 12 months postoperatively compared with those before operation (t=3.095, 3.079, <0.05). Although there was no significant difference in UCVA and MRSE, the cylinder was significantly reduced at 6 and 12 months postoperatively (t=-2.890, -2.435, P<0.05). Apex curvature (Kapex) and mean pupil power (MPP) within 4.5mm of central cornea decreased significantly (Z=-2.903, P<0.01; Z=-2.667, P<0.01). Even though the thinnest corneal thickness decreased from pre-operational (461.9±31.1) μm to post-operational (416.6±27.0) μm (Z=-3.059, P<0.01), the cornea became regular with keratometric asymmetry index of anterior corneal surface decreased (Z=-2.667, P<0.01). The corneal optical quality parameters were improved. There was no significant difference in ECD, HEX and CV at 12 months postoperatively (P>0.05). Twelve months after operation, grade 0, 0.5, 1 and 2 haze were seen on 20%, 55%, 20% and 5% corneas respectively. Conclusions: The topography guided excimer laser ablation combined with accelerated corneal collagen cross linking is safe and effective in treatment of early stage keratoconus. It can significantly improve corneal regularity while preventing keratoconus progression, so as to improve the best corrected visual acuity postoperatively. (Chin J Ophthalmol, 2019, 55: 904-910).

3D printed electrodes for efficient membrane capacitive deionization

There is increasing interests in cost-effective and energy-efficient technologies for the desalination of salt water. However, the challenge in the scalability of the suitable compositions of electrodes has significantly hindered the development of capacitive deionization (CDI) as a promising technology for the desalination of brackish water. Herein, we introduced a 3D printing technology as a new route to fabricate electrodes with adjustable composition, which exhibited large-scale applications as free-standing, binder-free, and robust electrodes. The 3D printed electrodes were designed with ordered macro-channels that facilitated effective ion diffusion. The high salt removal capacity of 75 mg g^-1 was achieved for membrane capacitive deionization (MCDI) using 3D printed nitrogen-doped graphene oxide/carbon nanotube electrodes with the total electrode mass of 20 mg. The improved mechanical stability and strong bonding of the chemical components in the electrodes allowed a long cycle lifetime for the MCDI devices. The adjusted operational mode (current density) enabled a low energy consumption of 0.331 W h g^-1 and high energy recovery of ∼27%. Furthermore, the results obtained from the finite element simulations of the ion diffusion behavior quantified the structure-function relationships of the MCDI electrodes.

Design Multifunctional Catalytic Interface: Toward Regulation of Polysulfide and Li2 S Redox Conversion in Li-S Batteries

The polysulfide shuttle effect and sluggish reaction kinetics hamper the practical applications of lithium-sulfur (Li-S) batteries. Incorporating a functional interlayer to trapping and binding polysulfides has been found effective to block polysulfide migration. Furthermore, surface chemistry at soluble polysulfides/electrolyte interface is a crucial step for Li-S battery in which stable cycling depends on adsorption and reutilization of blocked polysulfides in the electrolyte. A multifunctional catalytic interface composed of niobium nitride/N-doped graphene (NbN/NG) along the soluble polysulfides/electrolyte is designed and constructed to regulate corresponding interface chemical reaction, which can afford long-range electron transfer surfaces, numerous strong chemisorption, and catalytic sites in a working lithium-sulfur battery. Both experimental and theoretical calculation results suggest that a new catalytic interface enabled by metal-like NbN with superb electrocatalysis anchored on NG is highly effective in regulating the blocked polysulfide redox reaction and tailoring the Li₂ S nucleation-growth-decomposition process. Therefore, the Li-S batteries with multifunctional NbN/NG barrier exhibit excellent rate performance (621.2 mAh g^-1 at 3 C) and high stable cycling life (81.5% capacity retention after 400 cycles). This work provides new insights to promote Li-S batteries via multifunctional catalytic interface engineering.

Graphene-Induced in Situ Growth of Monolayer and Bilayer 2D SiC Crystals Toward High-Temperature Electronics

A reproducible graphene-induced in situ process is demonstrated for the first time for growing large-scale monolayer and bilayer cubic silicon carbide (SiC) crystals on a liquid Cu surface by chemical vapor deposition (CVD) method. Precise control over the morphology of SiC crystals is further realized by modulating growth conditions, thus leading to the formation of several shaped SiC crystals ranging from triangular, rectangular, pentagonal, and even to hexagonal kind. Simulations based on density functional theory are carried out to elucidate the growth mechanism of SiC flakes with various morphologies, which are in striking consistency with experimental observations. In the liquid Cu-assisted CVD system, growth temperature (∼1100 °C) enables sublimation and deposition of silicon oxide (SiO₂) derived from quartz tube, while liquid Cu facilitates preformation of graphene originated from methane. The SiO₂ and graphene, grown and reacted in situ in the CVD process, are served as the silicon and carbon source for the cubic SiC crystals, respectively. Moreover, the gradual transformation process from SiO₂ particles to SiC flakes is directly observed, with several middle stages clearly displayed. The direct in situ growth of SiC crystals offers a novel method for scaled production of SiC crystals and is beneficial to understand its growth mechanism, and thus push forward the way to develop high-temperature and high-frequency electronic devices.

Polypyrrole coated niobium disulfide nanowires as high performance electrocatalysts for hydrogen evolution reaction

Developing an environmentally friendly and low-cost approach to improve electrocatalytic activity for hydrogen evolution reaction (HER) has drawn wide attention due to its significant value and challenge. NbS₂-based materials exhibit high performance catalytic activity in electrochemical area, but its poor stability and synthetic difficulty limits its development and application. This work reports on the enhancement of HER performance through the utilization of conductive polymer polypyrrole (Ppy) on NbS₂ nanowires as electrocatalysts, which can be easily prepared. The Ppy coated NbS₂ nanowires obtain excellent catalytic activity for HER with low onset potential (-56 mV) and much lower overpotential (-219 mV) at a current of -10 mA cm^-2 compared with bare NbS₂ nanowires.

High-Concentration Niobium-Substituted WS2 Basal Domains with Reconfigured Electronic Band Structure for Hydrogen Evolution Reaction

Extrinsically controlling the intrinsic activity and stability of two-dimensional (2D) semiconducting materials by substitutional doping is crucial for energy-related applications. However, an in situ transition-metal doping strategy for uniform and large-area chemical vapor deposited 2D semiconductors remains a formidable challenge. Here, we successfully synthesize highly uniform niobium-substituted tungsten disulfide (Nb-WS₂) monolayers, with a doping concentration of nearly 7% and sizes reaching 100 μm, through a metal dopant precursor route, using salt-catalyzed chemical vapor deposition (CVD). Our results reveal unusual effects in the structural, optical, electronic, and electrocatalysis characteristics of the Nb-WS₂ monolayer. The Nb dopants readily induce a band restructuring effect, providing the most active site with a hydrogen adsorption energy of 0.175 eV and hence greatly improving its hydrogen evolution activity_. The combined advantages of the unusual physics and chemistry by in situ CVD doping technique open the possibility in designing 2D-material-based electronics and catalysts of novel functionalities.

Boosting Sodium Storage of Fe1-xS/MoS2 Composite via Heterointerface Engineering

Improving the cycling stability of metal sulfide-based anode materials at high rate is of great significance for advanced sodium ion batteries. However, the sluggish reaction kinetics is a big obstacle for the development of high-performance sodium storage electrodes. Herein, we have rationally engineered the heterointerface by designing the Fe_1-xS/MoS₂ heterostructure with abundant "ion reservoir" to endow the electrode with excellent cycling stability and rate capability, which is proved by a series of in and ex situ electrochemical investigations. Density functional theory calculations further reveal that the heterointerface greatly decreases sodium ion diffusion barrier and facilitates charge-transfer kinetics. Our present findings not only provide a deep analysis on the correlation between the structure and performance, but also draw inspiration for rational heterointerface engineering toward the next-generation high-performance energy storage devices.

TNF-α Suppresses Autophagic Flux in Acinar Cells in IgG4-Related Sialadenitis

IgG4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated systemic fibroinflammatory disease that affects salivary glands and leads to hyposalivation. Tumor necrosis factor-α (TNF-α) is a critical proinflammatory cytokine involved in several salivary gland disorders, but its role and mechanism regarding acinar cell injury in IgG4-RS are unknown. Here, we found that TNF-α level was significantly increased in serum and submandibular gland (SMG) of patients and that serum TNF-α level was negatively correlated with saliva flow rate. Ultrastructural observations of IgG4-RS SMGs revealed accumulation of large autophagic vacuoles, as well as dense fibrous bundles, decreased secretory granules, widened intercellular spaces, swollen mitochondria, and expanded endoplasmic reticulum. Expression levels of LC3 and p62 were both increased in patients' SMGs. TNF-α treatment led to elevated levels of LC3II and p62 in both SMG-C6 cells and cultured human SMG tissues but did not further increase their levels when combined with bafilomycin A1 treatment. Moreover, transfection of Ad-mCherry-GFP-LC3B in SMG-C6 cells confirmed the suppression of autophagic flux after TNF-α treatment. Immunofluorescence imaging revealed that costaining of LC3 and the lysosomal marker LAMP2 was significantly decreased in patients, TNF-α-treated SMG-C6 cells, and cultured human SMGs, indicating a reduction in autophagosome-lysosome fusion. Furthermore, the ratio of pro/mature cathepsin D was elevated in vivo, ex vivo, and in vitro. TNF-α also appeared to induce abnormal acidification of lysosomes in acinar cells, as assessed by lysosomal pH and LysoTracker DND-26 fluorescence intensity. In addition, TNF-α treatment induced transcription factor EB (TFEB) redistribution in SMG-C6 cells, which was consistent with the changes observed in IgG4-RS patients. TNF-α increased the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, and inhibition of ERK1/2 by U0126 reversed TNF-α-induced TFEB redistribution, lysosomal dysfunction, and autophagic flux suppression. These findings suggest that TNF-α is a key cytokine related to acinar cell injury in IgG4-RS through ERK1/2-mediated autophagic flux suppression.

A MoS2-MWCNT based fluorometric nanosensor for exosome detection and quantification

Circulating exosomes in body fluids are involved in many diseases and have important roles in pathophysiological processes. Specifically, they have emerged as a promising new class of biomarkers in cancer diagnosis and prognosis because of their high concentration and availability in a variety of biological fluids. The ability to quantitatively detect and characterize these nano-sized vesicles is crucial to make use of exosomes as a reliable biomarker for clinical applications. However, current methods are mostly technically challenging and time-consuming which prevents them from being adopted in clinical practice. In this work, we have developed a rapid sensitive platform for exosome detection and quantification by employing MoS₂-multiwall carbon nanotubes as a fluorescence quenching material. This exosome biosensor shows a sensitive and selective biomarker detection. Using this MoS₂-MWCNT based fluorometric nanosensor to analyze exosomes derived from MCF-7 breast cancer cells, we found that CD63 expression could be measured based on the retrieved fluorescence of the fluorophore with a good linear response range of 0-15% v/v. In addition, this nanosensing technique is able to quantify exosomes with different surface biomarker expressions and has revealed that exosomes secreted from MCF-7 breast cancer cells have a higher CD24 expression compared to CD63 and CD81.

An all manganese-based oxide nanocrystal cathode and anode for high performance lithium-ion full cells

Manganese oxide nanocrystals are of great interest for producing advanced high-performance lithium ion batteries owing to the shortened lithium ion diffusion length and accelerated interfacial charge transfer rate. Here we have developed a well-controlled generic method to synthesize monodisperse MnO nanocrystals, and present a comparative study regarding the effect of crystallite size on electrochemical stability. Nanocrystalline MnO with a size of about 10 nm shows the optimal lithium-storage performance. Notably, Mn-based nanocrystals retain their stable cyclability and excellent high-rate performance as both the anode and cathode. The all-nanocrystal MnO/C//LMO Li-ion full cells not only significantly improve the electrochemical properties of Mn-based materials but also open up avenues for the future development of various energy devices.

A Study of MnO2 with Different Crystalline Forms for Pseudocapacitive Desalination

Recent research on materials for capacitive deionization (CDI) has shown that intercalation materials have salt removal capacities (>40 mg g^-1) much higher than those of carbon materials (∼15 mg g^-1). However, little work has been done to elucidate the relationship between the microstructure of an intercalation material and its desalination performance. Herein, we report the desalination performances of various crystalline forms of MnO₂ in a hybrid CDI setup without the use of ion-exchange membranes. MnO₂ materials used in our experiments were either poorly crystalline or crystalline forms of 1D hollandite α-MnO₂, 2D birnessite δ-MnO₂, and 3D spinel λ-MnO₂. X-ray photoelectron spectroscopy performed on electrochemically cycled MnO₂ showed redox changes associated with intercalation processes in crystalline MnO₂, whereas poorly crystalline MnO₂ showed no such changes. It was further shown that surface adsorption is dominant in poorly crystalline MnO₂ and that poorly crystalline forms of α-MnO₂ and δ-MnO₂ exhibited the highest salt removal capacities of 0.17 and 0.16 mmol g^-1 (9.93 and 9.35 mg g^-1), respectively. These performances are comparable to state-of-the-art carbon materials and are remarkable considering the low surface areas (<400 m² g^-1) of MnO₂ materials.

Free-standing flexible film as a binder-free electrode for an efficient hybrid deionization system

In recent years, capacitive deionization (CDI) has emerged as an energy efficient and cost-effective technology for the desalination of brackish water. However, high energy consumption and poor desalting efficiency at high salinity levels have hampered the application of CDI for seawater (∼35 000 mg L-1). A novel method of CDI termed hybrid capacitive deionization (HCDI) employs the use of a faradaic electrode paired with a capacitive electrode. Doing so increases the salt removal capacity to approximately three times that of conventional activated carbon (AC) materials (∼10 mg g-1). Herein, we report experimental results of our HCDI cell using free-standing Na2Ti3O7-CNT@reduced graphene oxide (NCNT@rGO) film as a binder-free negative and activated carbon@reduced graphene oxide (AC@rGO) film as the positive electrode. The HCDI cell is operated under a constant current mode. During desalination, sodium ions are intercalated into the negative electrode (NCNT@rGO) whereas chloride ions are adsorbed onto the surface of the positive electrode (AC@rGO). We observed a high removal capacity of 129 mg g-1 at the low energy consumption of 0.4 W h g-1 for a salt concentration of ∼3000 mg L-1 at 50 ml min-1 flow rate. The higher performance of our electrodes over conventional ones (∼109 mg g-1, 0.68 W h g-1) is attributed to the absence of binders or conductive additives and the unique nano-architectured sandwich structure of NCNT@rGO. The advantageous features of our electrodes shed new insight into the development of CDI materials and show promise for low-cost, scalable systems.