Host Genetic Background Impacts Microbiome Composition in Newborn Alligator

Genetic factors play a key role in determination of the structure of the cloacal flora for newborn Chinese Alligators.We collected the cloacal microbiomes for 24 newborn Chinese Alligators from three different genetic backgrounds for 16S gene amplicon sequencing.The number of cloacal flora for the Chinese Alligators from different groups was comparable but differed structurally.There were variations in proportions of floral compositions at the phylum and family levels;however,the main difference was at the genus level.There were two significant differences in richness and evenness among the three groups.Non-metric multidimensional scaling NMDS analysis revealed that the 24 samples could be clearly divided into three categories based on their genetic backgrounds(stress=0.0244).Thus,we postulated that newborn Chinese Alligators with different genetic backgrounds have different immune strengths,which affects individual responses to environmental microorganisms.In summary,newborn Chinese Alligators from different genetic backgrounds exhibit variations in cloacal microbiome.

Acupuncture at Baihui and Dazhui reduces brain cell apoptosis in heroin readdicts

Acupuncture at Baihui （GV20） and Dazhui （GV14） reduces neuronal loss and attenuates ultra- structural damage in cerebral ischemic rats. However, whether acupuncture can treat addiction and prevent readdiction through changes to brain cell ultrastructure remains unknown. In this study, cell apoptosis was observed in the hippocampus and frontal lobe of heroin readdicted rats by electron microscopy. Immunohistochemical staining displayed a reduction in Bcl-2 ex- pression and an increase in Bax expression in the hippocampus and frontal lobe. After rats were given acupuncture at Baihui and Dazhui, the pathological damage in the hippocampus and frontal lobe was significantly reduced, Bcl-2 expression was upregulated and Bax expression was downregulated. Acupuncture exerted a similar effect with methadone, a commonly used drug for clinical treatment of drug addiction. Experimental findings suggest that acupuncture at Dazhui and Baihui can prevent brain cell apoptosis in heroin readdicted rats.

Normalization of ventral tegmental area structure following acupuncture in a rat model of heroin relapse

Drugs can cause obvious damage to the brain. To verify the relationship between acupuncture, neurotrophic factor expression and brain cell structural changes, this study established a rat model of heroin relapse using intramuscular injection of increasing amounts of heroin. During the detoxification period, rat models received acupuncture at Baihui （DU20） and Dazhui （DU14）. Electron microscopy demonstrated that the structure of the ventral tegmental area in heroin relapse rats gradually became normalized after acupuncture treatment. Immunohistochem- ical staining exhibited that the expression of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor increased in the ventral tegmental area following acupuncture. Moreover, the effects were similar to that of methadone, a type of medicine called an opioid. Results suggested that acupuncture at Baihui and Dazhui protected brain neurons against injury in rats with heroin relapse by promoting brain-derived neurotrophic factor and glial cell line-de-rived neurotrophic factor expression.

Effect of alcohol solvents treated ZrO(OH)_2 hydrogel on properties of ZrO_2 and its catalytic performance in isosynthesis

A series of ZrO2 catalysts were prepared by treating ZrO（OH）2 hydrogel with different alcohol solvents （C2-C4 alcohols） and calcining under N2 flow at 773 K for 3 h. The obtained ZrO2 catalysts were systematically characterized by the methods of N2 adsorption-desorption, powder X-ray diffraction, NH3 temperature-programmed desorption, and CO2 temperature-programmed desorption. The catalytic performance of each catalyst was evaluated in the selective synthesis of iso-C4 （isobutene and isobutane） and light olefins （C2-C4） from CO hydrogenation. The specific surface area increased for the ZrO2 catalysts obtained by treating ZrO（OH）2 hydrogel with different alcohol solvents. The amounts of both acidic and basic sites on the catalyst surface increased obviously. The catalytic activity （CO conversion） of ZrO2 catalysts also increased after the treatment with different alcohol solvents. The nighest activity was obtained over the catalyst which was pretreated with isopropanol. However, alcohol solvent treatment retarded the transformation of ZrO2 crystal structure from tetragonal phase to monoclinic phase, and subsequently resulted in the decrease of monoclinic phase in ZrO2, which led to the decrease of olefin selectivity in corresponding hydrocarbon products （C2-C4/CH）.

Light People: Academician Junhao Chu

Editorial The industrial revolutions of steam power,electric power and digital power have been three key steps in the development of science and technology.Now,the fourth industrial revolution has quietly begun,a revolution which will combine the powers of modern technologies such as the Internet,industrial digitalization and virtual reality to trigger a major change of science and technology,and sensor technology is of vital importance to this process.

Highly dispersed Ni/MgO-mSiO_(2)catalysts with excellent activity and stability for dry reforming of methane

Highly dispersed Ni catalyst and alkaline promoters supported by mesoporous SiO_(2)nanospheres were synthesized and applied as an active and stable catalyst for dry reforming of methane(DRM).The as-prepared Ni/MgO-mSiO_(2)catalyst showed stable conversions of CH4 and CO_(2)around 82%and 85%in 120 h of DRM reaction,which was superior in performance compared to similar catalysts in literatures.Based on the transmission electron microscope(TEM)images,energy-dispersive spectroscopy(EDS),CO-pulse adsorption,temperature programmed reduction of the oxidized catalysts by hydrogen(H_(2)-TPR),X-ray photoelectron spectroscopy(XPS),temperature-programmed desorption of CO_(2)(CO_(2)-TPD),and thermal gravitational analysis(TGA),the promotion effect of MgO on the Ni catalyst was systematically studied.The introduction of Mg^(2+)in synthesis enhanced the interaction between Ni^(2+)and mSiO_(2),which led to a high dispersion of active centers and a strong“metal–support”interactions to inhibit the sintering and deactivation of Ni at reaction temperatures.On the other hand,Ni and MgO nanoparticles formed adjacently on mSiO_(2),where the“Ni-MgO”interface not only improved the Ni0 distribution and promoted the cracking of CH_(4)but also promoted the activation of CO_(2)and the elimination of carbon deposits.A high and stable conversion of CH4 and CO_(2)were then achieved through the synergistic effect of Ni catalyst,MgO promoter,and mSiO_(2)support.

Effects of interlayer coupling on the excitons and electronic structures of WS_(2)/hBN/MoS_(2) van der Waals heterostructures

Inserting hexagonal boron nitride(hBN)as barrier layers into bilayer transition metal dichalcogenides heterointerface has been proved an efficient method to improve two dimensional tunneling optoelectronic device performance.Nevertheless,the physical picture of interlayer coupling effect during incorporation of monolayer(1L-)hBN is not explicit yet.In this article,spectroscopic ellipsometry was used to experimentally obtain the broadband excitonic and critical point properties of WS_(2)/MoS_(2)and WS_(2)/hBN/MoS_(2)van der Waals heterostructures.We find that 1L-hBN can only slightly block the interlayer electron transfer from WS_(2)layer to MoS_(2)layer.Moreover,insertion of 1L-hBN weakens the interlayer coupling effect by releasing quantum confinement and reducing efficient dielectric screening.Consequently,the exciton binding energies in WS_(2)/hBN/MoS_(2)heterostructures blueshift comparing to those in WS_(2)/MoS_(2)heterostructures.In this exciton binding energies tuning process,the reducing dielectric screening effect plays a leading role.In the meantime,the quasi-particle(QP)bandgap remains unchanged before and after 1L-hBN insertion,which is attributed to released quantum confinement and decreased dielectric screening effects canceling each other.Unchanged QP bandgap as along with blueshift exciton binding energies lead to the redshift exciton transition energies in WS_(2)/hBN/MoS_(2)heterostructures.

Versatile band structure and electron-phonon coupling in layered PtSe_(2) with strong interlayer interaction

The large tunability in the band structure is ubiquitous in two-dimensional(2D)materials,and PtSe_(2) is not an exception,which has attracted considerable attention in electronic and optoelectronic applications due to its high carrier mobility and long-term airstability.Such dimensional dependent properties are closely related to the evolution of electronic band structures.Critical points(CPs),the extrema or saddle points of electronic bands,are the cornerstone of condensed-matter physics and fundamentally determine the optical and transport phenomena of the layered PtSe_(2).Here,we have experimentally revealed the detailed electronic structures in layered PtSe_(2),including the CPs in the Brillouin zones(BZs),by means of reflection contrast spectroscopy and spectroscopic ellipsometry(SE).There are three critical points in the BZs attributed to the excitonic transition,quasi-particle band gap,and the band nesting effect related transition,respectively.Three CPs show red-shifting trends with increasing layer number under the mechanism of strong interlayer coupling.We have further revealed the electron–phonon(e–ph)interaction in such layered material,utilizing temperature-dependent absorbance spectroscopy.The strength of e–ph interaction and the average phonon energy also decline with the increasement of layer number.Our findings give a deep understanding to the physics of the layer-dependent evolution of the electronic structure of PtSe_(2),potentially leading to applications in optoelectronics and electronic devices.

Resistance of large caisson in floating transport considering the influence of air

This paper deals with the floating resistance of super large caisson by numerical simulation,and the influence of air resistance on the caisson,which is often ignored by previous researchers,is considered.The floating caisson of Taizhou Highway Bridge’s middle tower pier is investigated,and the software package FLUENT is used to simulate the floating process of largescale rounded rectangular steel caisson.This simulation adopts the volume of fluid(VOF)model with water-air two-phase flow,which can take both the hydraulic resistance and air resistance into account.Subsequently,the analyses on hydraulic resistance and air resistance under different working conditions,such as different flow velocities and different draughts of water are performed,and the results are compared with those calculated by related empirical formula.The comparison shows that the air resistance takes up notable portion in the total resistance on the floating caisson,and the effect of air resistance on the safety of caisson should be paid sufficient attention to rather than be ignored.

The marriage of sealant agent between structure transformable silk fibroin and traditional Chinese medicine for faster skin repair

Fast skin repair is critical for less infection, less pain and high quality of life, which is still limited with undesirable rehabilitation speed and side effects. Currently, laser-activated silk sealant agent without suture and gauze has been demonstrated promising for fast skin repair taking advantage of its structural transformation after heating. Nevertheless, more efficient healing effects and less side effects of laseractivated silk sealant agent remains challenging due to absence of suitable photo-thermal materials and robust/biomimetic protein materials. In this work, the marriage between silk protein and Rehmanniae radix preparata(a kind of the traditional Chinese herb) has been demonstrated as a novel and effective way to achieve an excellent healing effect for skin repair. The non-toxicity, high photothermal conversion efficiency and healing mechanism are systematically studied and proved. This new methodology might shed a new light for combining dark traditional Chinese medicine and silk fibroin for advanced wound healing technology.

Steam reforming of toluene as a tar model compound with modified nickel-based catalyst

Catalytic steam reforming is a promising route for tar conversion to high energy syngas in the process of biomass gasification. However, the catalyst deactivation caused by the deposition of residual carbon is still a major challenge. In this paper, a modified Ni-based Ni-Co/Al2O3-CaO (Ni-Co/AC) catalyst and a conventional Ni/Al2O3 (Ni/A) catalyst were prepared and tested for tar catalytic removal in which toluene was selected as the model component. Experiments were conducted to reveal the influences of the reaction temperature and the ratio between steam to carbon on the toluene conversion and the hydrogen yield. The physicochemical properties of the modified Ni-based catalyst were determined by a series of characterization methods. The results indicated that the Ni-Co alloy was determined over the Ni-Co/AC catalyst. The doping of CaO and the presence of Ni-Co alloy promoted the performance of toluene catalytic dissociation over Ni-Co/AC catalyst compared with that over Ni/A catalyst. After testing in steam for 40 h, the carbon conversion over Ni-Co/AC maintained above 86% and its resistance to carbon deposition was superior to Ni/A catalyst.

Strong electron–phonon coupling influences carrier transport and thermoelectric performances in group-IV/V elemental monolayers

The interactions between electrons and phonons play the key role in determining the carrier transport properties in semiconductors.In this work,comprehensive investigations on full electron–phonon(el–ph)couplings and their influences on carrier mobility and thermoelectric(TE)performances of 2D group IV and V elemental monolayers are performed,and we also analyze the selection rules on el–ph couplings using group theory.For shallow n/p-dopings in Si,Ge,and Sn,ZA/TA/LO phonon modes dominate the intervalley scatterings.Similarly strong intervalley scatterings via ZA/TO phonon modes can be identified for CBM electrons in P,As,and Sb,and for VBM holes,ZA/TA phonon modes dominate intervalley scatterings in P while LA phonons dominate intravalley scatterings in As and Sb.By considering full el–ph couplings,the TE performance for these two series of monolayers are predicted,which seriously downgrades the thermoelectric figures of merits compared with those predicted by the constant relaxation time approximation.