MXenes, 2D compounds generated from layered bulk materials, have attracted significant attention in energy‐related fields. However, most syntheses involve HF, which is highly corrosive and harmful to ...lithium‐ion battery and supercapacitor performance. Here an alkali‐assisted hydrothermal method is used to prepare a MXene Ti3C2Tx (T=OH, O). This route is inspired from a Bayer process used in bauxite refining. The process is free of fluorine and yields multilayer Ti3C2Tx with ca. 92 wt % in purity (using 27.5 m NaOH, 270 °C). Without the F terminations, the resulting Ti3C2Tx film electrode (ca. 52 μm in thickness, ca. 1.63 g cm−3 in density) is 314 F g−1 via gravimetric capacitance at 2 mV s−1 in 1 m H2SO4. This surpasses (by ca. 214 %) that of the multilayer Ti3C2Tx prepared via HF treatments. This fluorine‐free method also provides an alkali‐etching strategy for exploring new MXenes for which the interlayer amphoteric/acidic atoms from the pristine MAX phase must be removed.
High‐purity (92 wt %) Ti3C2Tx (T=OH, O) is obtained by an alkali‐assisted hydrothermal route that is totally free of HF. The obtained Ti3C2Tx terminated with OH/O shows a gravimetric capacitance (314 F g−1) that surpasses its HF‐etched counterparts by about 214 %. This method provides an alkali‐etching strategy for MXenes in which the interlayer amphoteric/acidic atoms from the pristine MAX phase must be removed.
Fecal microbiota transplantation (FMT) is a microbiota-based therapy that shows therapeutic potential in recurrent or refractory Clostridium difficile infections and other intestinal or ...extra-intestinal disorders. Nonetheless, adverse events (AEs) remain a major challenge in the application of FMT.
To review the AEs of FMT and to address the concerns of safety during the procedure.
Publications were retrieved in the databases of Medline, Embase and Cochrane Library. AEs were classified according to their causality with FMT or their severity.
A total of 7562 original articles about FMT were identified in this study, 50 of them fulfilled the inclusion criteria. Totally 78 kinds of AEs were revealed enrolled in these 50 selected publications. The total incidence rate of AEs was 28.5%. Among the 42 publications, 5 kinds were definitely and 38 kinds were probably related to FMT. The commonest FMT-attributable AE was abdominal discomfort, which was reported in 19 publications. For upper gastrointestinal routes of FMT, 43.6% (89/204) patients were compromised by FMT-attributable AE, while the incidence dropped to 17.7% (76/430) for lower gastrointestinal routes. In contrast, the incidences of serious adverse events (SAEs) were 2.0% (4/196) and 6.1% (40/659) for upper and lower gastrointestinal routes, respectively. A total of 44 kinds of SAEs occurred in 9.2% patients, including death (3.5%, 38/1089), infection (2.5%, 27/1089), relapse of inflammatory bowel diseases (0.6%, 7/1089) and Clostridium difficile infection (0.9%, 10/1089).
Consequently, both AEs and SAEs are not rare and should be carefully monitored throughout FMT. However, high quality randomized controlled trials are still needed for the more definite incidence of AEs of FMT.
•UHPFRC filled steel tubular (UHPFRCFST) members have been tested under lateral impact loading.•UHPFRCFST members exhibit higher lateral impact resistance than the normal strength concrete (NSC) ...filled steel tubular (NSCFST) members.•Finite element (FE) model is developed and validated by the test results.•Parametric analyses have been carried out by using the developed FE model.
This study investigates the behavior of ultra-high performance fiber-reinforced concrete (UHPFRC) filled steel tubular (UHPFRCFST) members under lateral impact loading. A total of five specimens were prepared and tested under lateral impact loading. All specimens were 168 mm in diameter and 2000 mm in length. In addition to UHPFRCFST members, normal strength concrete (NSC) filled steel tubular (NSCFST) members were also tested for comparison purpose. Other investigated parameters in this study include the impact energy and the presence of an inner void. The test results show that as compared to the NSCFST members, the UHPFRCFST members exhibit higher lateral impact resistance with higher peak and plateau impact forces, smaller deflection, and less local indentation. With the increase of impact energy, the peak impact force, the impact duration, and the deflection of the UHPFRCFST members are increased, while the plateau impact force is almost kept constant. Moreover, the presence of an inner void does not deteriorate the lateral impact resistance of the UHPFRCFST members. Finite element (FE) model was then developed and validated by the test results in this study. Afterwards, full-range analysis was performed to investigate the damage evolution, sectional bending moment distribution, and the interactions between the steel tube and the concrete during the impact process. Finally, detailed parametric analyses were carried out to investigate the influences of different parameters on the lateral impact behavior of UHPFRCFST members.
The gut microbiota plays an important role in maintaining intestinal homeostasis. Dysbiosis is associated with intestinal tumorigenesis. Deoxycholic acid (DCA), a secondary bile acid increased by a ...western diet, correlates with intestinal carcinogenesis. However, evidence relating bile acids, intestinal microbiota and tumorigenesis are limited. In our study, we investigated the effect of DCA on induction of intestinal dysbiosis and its roles in intestinal carcinogenesis. Alteration of the composition of the intestinal microbiota was induced in DCA‐treated APCmin/+ mice, which was accompanied by impaired intestinal barrier, gut low grade inflammation and tumor progression. The transfer of fecal microbiota from DCA‐treated mice to another group of Apcmin/+ mice increased tumor multiplicity, induced inflammation and recruited M2 phenotype tumor‐associated macrophages. Importantly, the fecal microbiota transplantation activated the tumor‐associated Wnt/β‐catenin signaling pathway. Moreover, microbiota depletion by a cocktail of antibiotics was sufficient to block DCA‐induced intestinal carcinogenesis, further suggesting the role of dysbiosis in tumor development. Our study demonstrated that alteration of the microbial community induced by DCA promoted intestinal carcinogenesis.
What's new?
Microbial imbalance in the intestines, or gut dysbiosis, is a suspected contributor to intestinal tumor development. Likewise, deoxycholic acid (DCA), a secondary bile acid elevated by a high‐fat diet, is thought to be pro‐carcinogenic. Our study shows that the two factors, working together, pave the way to intestinal tumorigenesis. In mutationally predisposed mice, DCA‐induced dysbiosis disrupted intestinal barrier function, promoted recruitment of tumor‐associated macrophages and accelerated intestinal carcinogenesis via activation of Wnt/β‐catenin signaling. DCA‐induced tumor growth and inflammation were reduced in mice depleted of gut microbiota by antibiotic supplementation, further implicating DCA and gut dysbiosis in intestinal carcinogenesis.
The authors use a statistical regional climate model Statistical Regional Model (STAR) to project the Tibetan Plateau (TP) climate for the period 2015–50. Reanalysis datasets covering 1958–2001 are ...used as a substitute of observations and resampled by STAR to optimally fit prescribed linear temperature trends derived from the Max Planck Institute Earth System Model (MPI-ESM) simulations for phase 5 of the Coupled Model Intercomparison Project (CMIP5) under the representative concentration pathway 2.6 (RCP2.6) and RCP4.5 scenarios. To assess the related uncertainty, temperature trends from carefully selected best/worst ensemble members are considered. In addition, an extra projection is forced by observed temperature trends in 1958–2001. The following results are obtained: (i) Spatial average temperature will increase by 0.6°–0.9°C; the increase exceeds 1°C in all months except in boreal summer, thus indicating a reduced annual cycle; and daily minimum temperature rises faster than daily maximum temperature, resulting in a narrowing of the diurnal range of near-surface temperature. (ii) Precipitation increase mainly occurs in early summer and autumn possibly because of an earlier onset and later withdrawal of the Asian summer monsoon. (iii) Both frost and ice days decrease by 1–2 days in spring, early summer, and autumn, and the decrease of frost days on the annual course is inversely related to the precipitation increase. (iv) Degree-days increase all over the TP with peak amplitude in the Qaidam Basin and the southern TP periphery, which will result in distinct melting of the local seasonal frozen ground, and the annual temperature range will decrease with stronger amplitude in south TP.
ABSTRACT
The El Niño–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) are high degree synergic air–sea interactions greatly affecting the interannual variability of rainfall in China. This ...study reveals the possible cooperative impacts of the ENSO and IOD on boreal autumn rainfall anomalies in China, on the basis of data analysis collected during 1951–2010. Our results suggest that the positive phase of the combined ENSO and IOD events may result in an anomalous lower‐level anticyclone over the western North Pacific (WNP) region, with a southward shift of the strengthened East Asian jet stream (EAJS). An enhanced moisture supply is transported to increase autumn rainfall over southern China by the southwesterly winds. In the negative phase, however, southerly anomalies are observed between the anomalous cyclone and anticyclone over the Indo‐China Peninsula and the WNP, which carry more moisture to the Loess Plateau (LP) area with a northward shift of the weakened EAJS, leading to an increase of autumn rainfall in this area. Note that the negative IOD plays an important role in the cooperative influences on the autumn rainfall anomalies over the LP in that the associated anomalous lower‐level cyclone shifts westward compared to the impacts of the pure La Niña. The regional asymmetric responses of autumn rainfall to the positive and negative phases of the ENSO and IOD could be attributed to the different responses of lower‐level circulation over WNP and the meridional shift of the upper‐level EAJS. Results demonstrate that the combined ENSO and IOD induce an anomalous zonal gradient of sea surface temperature (SST) over the tropical Indo‐Pacific Ocean to alter the convection anomalies over the Indo‐Pacific warm pool that further affect the upper and lower atmospheric circulations by means of a Rossby wave response.
Supramolecular chirality typically originates from either chiral molecular building blocks or external chiral stimuli. Generating chirality in achiral systems in the absence of a chiral input, ...however, is non-trivial and necessitates spontaneous mirror symmetry breaking. Achiral nematic lyotropic chromonic liquid crystals have been reported to break mirror symmetry under strong surface or geometric constraints. Here we describe a previously unrecognised mechanism for creating chiral structures by subjecting the material to a pressure-driven flow in a microfluidic cell. The chirality arises from a periodic double-twist configuration of the liquid crystal and manifests as a striking stripe pattern. We show that the mirror symmetry breaking is triggered at regions of flow-induced biaxial-splay configurations of the director field, which are unstable to small perturbations and evolve into lower energy structures. The simplicity of this unique pathway to mirror symmetry breaking can shed light on the requirements for forming macroscopic chiral structures.
Dissipative Kerr soliton (DKS) featuring broadband coherent frequency comb with compact size and low power consumption, provides an unparalleled tool for nonlinear physics investigation and precise ...measurement applications. However, the complex nonlinear dynamics generally leads to stochastic soliton formation process and makes it highly challenging to manipulate soliton number and temporal distribution in the microcavity. Here, synthesized and reconfigurable soliton crystals (SCs) are demonstrated by constructing a periodic intra-cavity potential field, which allows deterministic SCs synthesis with soliton numbers from 1 to 32 in a monolithic integrated microcavity. The ordered temporal distribution coherently enhanced the soliton crystal comb lines power up to 3 orders of magnitude in comparison to the single-soliton state. The interaction between the traveling potential field and the soliton crystals creates periodic forces on soliton and results in forced soliton oscillation. Our work paves the way to effectively manipulate cavity solitons. The demonstrated synthesized SCs offer reconfigurable temporal and spectral profiles, which provide compelling advantages for practical applications such as photonic radar, satellite communication and radio-frequency filter.
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