Dielectric barrier discharge plasma synthesis of Ag/γ-Al_(2)O_(3) catalysts for catalytic oxidation of CO

In this study,Ag/γ-Al_(2)O_(3)catalysts were synthesized by an Ar dielectric barrier discharge plasma using silver nitrate as the Ag source andγ-alumina(γ-Al_(2)O_(3))as the support.It is revealed that plasma can reduce silver ions to generate crystalline silver nanoparticles(Ag NPs)of good dispersion and uniformity on the alumina surface,leading to the formation of Ag/γ-Al_(2)O_(3)catalysts in a green manner without traditional chemical reductants.Ag/γ-Al_(2)O_(3)exhibited good catalytic activity and stability in CO oxidation reactions,and the activity increased with increase in the Ag content.For catalysts with more than 2 wt%Ag,100%CO conversion can be achieved at 300°C.The catalytic activity of the Ag/γ-Al_(2)O_(3)catalysts is also closely related to the size of theγ-alumina,where Ag/nano-γ-Al_(2)O_(3)catalysts demonstrate better performance than Ag/micro-γ-Al_(2)O_(3)catalysts with the same Ag content.In addition,the catalytic properties of plasma-generated Ag/nano-γ-Al_(2)O_(3)(Ag/γ-Al_(2)O_(3)-P)catalysts were compared with those of Ag/nano-γ-Al_(2)O_(3)catalysts prepared by the traditional calcination approach(Ag/γ-Al_(2)O_(3)-C),with the plasma-generated samples demonstrating better overall performance.This simple,rapid and green plasma process is considered to be applicable for the synthesis of diverse noble metal-based catalysts.

麻疯树精细胞分离

将麻疯树成熟花粉置于一定渗透剂溶液中,可使其破裂,释放出其中的一对精细胞。释放的精细胞在20~30 min后用FDA染色仍可显示具有活性的荧光。用显微操作仪将释放的精细胞收集,得到一定数量具有活性的精细胞群体。研究了不同渗透剂浓度下释放的精细胞状态,比较了不同渗透剂的精细胞释放率及保持精细胞活性的最适浓度,以7.5%的葡萄糖溶液分离麻疯树精细胞的最佳浓度。麻疯树精细胞的成功分离为其离体受精实验奠定了一定基础,也为研究麻疯树精细胞发育的分子生物学实验提供了材料。

The effects of altered BMP4 signaling in first branchialarch- derived murine embryonic orofacial tissues

The first branchial arch(BA1),which is derived from cranial neural crest(CNC)cells,gives rise to various orofacial tissues.Cre mice are widely used for the determination of CNC and exploration of gene functions in orofacial development.However,there is a lack of Cre mice specifically marked BA1’s cells.Pax2-Cre allele was previously generated and has been widely used in the field of inner ear development.Here,by compounding Pax2-Cre and R26R-mTmG mice,we found a specific expression pattern of Pax2^(+)cells that marked BA1’s mesenchymal cells and the BA1-derivatives.Compared to Pax2-Cre;R26R-mTmG allele,GFP^(+)cells were abundantly found both in BA1 and second branchial arch in Wnt1-Cre;R26R-mTmG mice.As BMP4 signaling is required for orofacial development,we over-activated Bmp4 by using Pax2-Cre;pMes-BMP4 strain.Interestingly,our results showed bilateral hyperplasia between the upper and lower teeth.We also compare the phenotypes of Wnt1-Cre;pMes-BMP4 and Pax2-Cre;pMes-BMP4 strains and found severe deformation of molar buds,palate,and maxilla-mandibular bony structures in Wnt1-Cre;pMes-BMP4 mice;however,the morphology of these orofacial organs were comparable between controls and Pax2-Cre;pMes-BMP4 mice except for bilateral hyperplastic tissues.We further explore the properties of the hyperplastic tissue and found it is not derived from Runx2^(+)cells but expresses Msx1,and probably caused by abnormal cell proliferation and altered expression pattern of p-Smad1/5/8.In sum,our findings suggest altering BMP4 signaling in BA1-specific cell lineage may lead to unique phenotypes in orofacial regions,further hinting that Pax2-Cre mice could be a new model for genetic manipulation of BA1-derived organogenesis in the orofacial region.

Isolation and characterization of Bordetella pseudohinzii in mice in China

We report on the first detection and isolation of B.pseudohinzii(Bordetella pseudohinzii)in laboratory mice in China.Forty‐one B.pseudohinzii strains were isolated from 3094 mice in 33 different laboratory animal facilities in southern China.The isolates were identified through culture and genome sequenceing.Phylogenetic analysis based on the sequences of 16S rRNA and OmpA genes demonstrated that these strains were on the same clade as other B.pseudohinzii strains isolated from mice.Experimental infected mice presented an asymptomatic infection.B.pseudohinzii replicated in both the respiratory tract and the digestive tract.Most importantly B.pseudohinzii shed via feces and infected a group of sentinel mice in a separate cage via cage padding contaminated with B.pseudohinzii‐positive feces,indicating that B.pseudohinzii could transmit efficiently among mice and contaminate environmental facilities.Our study highlights the importance of routine monitoring of the pathogen in laboratory mice and provides vital insights into the transmission of Brodetellae in rodents and human.

Bacterial nanocellulose assembly into super-strong and humidity-responsive macrofibers

Cellulose macrofibers (MFs) are gaining increasing interest as natural and biodegradable alternatives to fossil-derived polymers for both structural and functional applications. However, simultaneously achieving their exceptional mechanical performance and desired functionality is challenging and requires complex processing. Here, we reported a one-step approach using a tension-assisted twisting (TAT) technique for MF fabrication from bacterial cellulose (BC). The TAT stretches and aligns BC nanofibers pre-arranged in hydrogel tubes to form MFs with compactly assembled structures and enhanced hydrogen bonding among neighboring nanofibers. The as-prepared BC MFs exhibited a very high tensile strength of 1 057 MPa and exceptional lifting capacity (over 340 000 when normalized by their own weight). Moreover, due to the volume expansion of BC nanofibers upon water exposure, BC MFs quickly harvested energy from environmental moisture to untwist the bundled networks, thus generating a torsional spinning with a peak rotation speed of 884 r/(min·m). The demonstrated rapid and intense actuation response makes the MFs ideal candidates for diverse humidity-response-based applications beyond advanced actuators, remote rain indicators, intelligent switches, and smart curtains.

Atmospheric heterogeneous reaction of chlorobenzene on mineralα-Fe_(2)O_(3)particulates:a chamber experiment study

Despite the large emission of chlorinated volatile organic compounds(CVOCs)into the atmosphere,the ultimate fate of these compounds remains largely unknown.Herein,we explore the photochemical conversion of an important class of CVOCs,namely chlorobenzene(CB),on mineralα-Fe_(2)O_(3)particulates under atmospheric relevant conditions.A series of chamber reactions composed of the CB with/without SO_(2)or NO_(2)are performed,followed by in situ diffuse reflectance infrared Fourier transform spectroscopy measurements and density functional theory calculations.We show that CB can be considerably degraded byα-Fe_(2)O_(3)under light irradiation,whereas the reaction is markedly suppressed by adding SO_(2)or NO_(2)owing to their competitive adsorption and surface acidification.In particular,we discover that CB can be ultimately converted into polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)under dark state or light irradiation,suggesting a possible origin of atmospheric PCDD/Fs from this overlooked photochemical source.

Catalytic destruction of chlorobenzene over K-OMS-2: Inhibition of high toxic byproducts via phosphate modification

In the process of catalytic destruction of chlorinated volatile organic compounds(CVOCs),the catalyst is prone to chlorine poisoning and produce polychlorinated byproducts with high toxicity and persistence,bringing great risk to atmospheric environment and human health.To solve these problems,this work applied phosphate to modify K-OMS-2 catalysts.The physicochemical properties of catalysts were determined by using X-ray powder diffraction(XRD),scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS),hydrogen temperature programmed reduction(H_(2)-TPR),pyridine adsorption Fouriertransform infrared(Py-IR)and water temperature programmed desorption(H_(2)O-TPD),and chlorobenzene was selected as a model pollutant to explore the catalytic performance and byproduct inhibition function of phosphating.Experimental results revealed that 1 wt.%phosphate modification yielded the best catalytic activity for chlorobenzene destruction,with the 90%conversion(T90)at approximately 247℃.The phosphating significantly decreased the types and yields of polychlorinated byproducts in effluent.After phosphating,we observed significant hydroxyl groups on catalyst surface,and the active centerwas transformed into Mn(IV)-O…H,which promoted the formation of HCl,and enhanced the dechlorination process.Furthermore,the enriched Lewis acid sites by phosphating profoundly enhanced the deep oxidation ability of the catalyst,which promoted a rapid oxidation of reaction intermediates,so as to reduce byproducts generation.This study provided an effective strategy for inhibiting the toxic byproducts for the catalytic destruction of chlorinated organics.

一种智能纳米酶工厂作为诊疗纳米平台用于协同癌症治疗

多模态疗法是结合多种疗法治疗通常复杂而隐蔽的肿瘤组织的最有希望的策略之一.尽管多功能纳米材料已被设计用于构建多模态疗法,但普遍存在的各组成部分之间的不充分协调可能导致协同治疗效果不佳,并妨碍其充分实现临床潜力.在此,受可控“集束炸弹”模型的启发,我们设计了一种智能、生物相容、多功能的纳米工厂系统(PDA@GOx@MnO_(2)-PEG),它封装了多种纳米试剂,以达到对肿瘤组织的高破坏效率.刺激反应性的外层二氧化锰作为“炸弹”的外壳可触发级联催化反应,并与GOx形成一个自给自足的环形催化链.PDA作为一种具有良好蛋白质携带能力的基质,实现了高的GOx负载.同时,其高效的光热转换效率显示了低温(~45℃)进一步提高GOx酶活性的潜力.值得注意的是,内部的GOx就像一个“子炸弹”,通过控制释放来增加肿瘤缺氧部位的积累,并在充足的氧气和低热度的帮助下充分发挥其葡萄糖消耗能力进行饥饿治疗.在这个体系中,各种纳米试剂相互配合,层层推进,充分发挥其威力,形成了一个自给自足的纳米工厂模型,通过协同策略实现了良好的低温光热-饥饿协同治疗.此外,该纳米复合材料表现出三态成像能力,可用于敏感诊断和实时监控治疗.这项研究为设计生物相容性和智能治疗纳米平台提供了新的见解,使精准医疗中的多模式治疗效果最大化.

A novel deep generative modeling-based data augmentation strategy for improving short-term building energy predictions

Short-term building energy predictions serve as one of the fundamental tasks in building operation management.While large numbers of studies have explored the value of various supervised machine learning techniques in energy predictions,few studies have addressed the potential data shortage problem in developing data-driven models.One promising solution is data augmentation,which aims to enrich existing building data resources for reliable predictive modeling.This study proposes a deep generative modeling-based data augmentation strategy for improving short-term building energy predictions.Two types of conditional variational autoencoders have been designed for synthetic energy data generation using fully connected and one-dimensional convolutional layers respectively.Data experiments have been designed to evaluate the value of data augmentation using actual measurements from 52 buildings.The results indicate that conditional variational autoencoders are capable of generating high-quality synthetic data samples,which in turns helps to enhance the accuracy in short-term building energy predictions.The average performance enhancement ratios in terms of CV-RMSE range between 12%and 18%.Practical guidelines have been obtained to ensure the validity and quality of synthetic building energy data.The research outcomes are valuable for enhancing the robustness and reliability of data-driven models for smart building operation management.

Termination of Transcription of LAT Increases the Amounts of ICP0 mRNA but Does Not Alter the Course of HSV-1 Infection in Latently Infected Murine Ganglia

On entering sensory ganglia,herpes simplex viruses 1(HSV-1)establishes a latent infection with the synthesis of a latency associated transcript(LAT)or initiates productive infection with expression of a set of immediate early viral proteins.The precise mechanisms how expression of a genes is suppressed during the latency are unknown.One mechanism that has been proposed is illustrated in the case of ICP0,a key immediate early viral regulatory protein.Specifically,the 2 kb LAT intron is complementary to the 30 terminal portion of ICP0 m RNA.To test the hypothesis that accumulation of LAT negatively affects the accumulation of ICP0 m RNA,we inserted a DNA fragment encoding two poly(A)sequences into LAT to early terminate LAT transcript without interrupting the complementary sequence of ICP0 transcript(named as SR1603).Comparisons of the parent(SR1601)and mutant(SR1603)HSV-1 viruses showed the following:Neurons harboring latent SR1603 virus accumulated equivalent amounts of viral DNA but higher amounts of ICP0 m RNA and lower amounts of LAT,when compared to neurons harboring the SR1601 virus.One notable difference between the two viruses is that viral RNA accumulation in explanted ganglia harboring SR1603 virus initiated significantly sooner than that in neurons harboring SR1601 virus,suggesting that ICP0 may act as an activator of viral gene expression in permissive cells.Collectively,these data suggest that increased ICP0 m RNA by suppressed LAT did not affect the establishment of latency in latently infected murine ganglia.

Regulation of exogenous bFGF gene mediated by recombinant adeno-associated virus in vitro

The regulatory effect of basicfibroblast growth factor(bFGF)mediated by recombinant adeno-associated virus(AAV)in vitro was investigated.Recombinant plasmid pAAV-S3-bFGF,and pSVneo were co-transfected into BHK-21 cells,then the recombinant AAV genome was replicated and packaged with the helper virus HSV1-rc/ΔUL2.The titer of the recombinant rAAV2-tet-off-bFGF was determined by dot-blot assay.MC3T3-E1 cells were infected with rAAV2-tet-off-bFGF.Regulatory effects of Doxycycline(Dox)on bFGF and osteogenic factors were assayed quantitatively by real-time reverse transcription-polymerase chain reaction(RT-PCR)and Western blot.The physical particle titer of rAAV2-tet-off-bFGF successfully constructed was 1.8�1012 vector genomes/mL,and the virus could infect MC3T3-E1 cells effectively.In MC3T3-E1 cells treated with Dox,the expression levels of exogenous bFGF and osteogenic factors declined to varying degrees.It was concluded that rAAV2-tet-off-bFGF could infect MC3T3 cells efficiently,and this recombinant system could be regulated success-fully by Dox in vitro.

Broadband 1T-polytype tantalum disulfide saturable absorber for solid-state bulk lasers

1T-polytype tantalum disulfide(1T-TaS_(2)),an emerging strongly correlated material,features a narrow bandgap of 0.2 e V,bridging the gap between zero-bandgap graphene and large-bandgap 2D nonlinear optical(NLO)materials.Combined with its intense light absorption,high carrier concentration,and high mobility,1T-TaS_(2) shows considerable potential for applications in broadband optoelectronic devices.However,its NLO characteristics and related applications have rarely been explored.Here,1T-TaS_(2) nanosheets are prepared by chemical vapor deposition.The ultrafast carrier dynamics in the 400–1100 nm range and broadband NLO performance in the 515–2500 nm range are systematically studied using femtosecond lasers.An obvious saturable absorption phenomenon is observed in the visible to IR range.The nonlinear absorption coefficient is measured to be-22.60±0.52 cm MW-1under 1030 nm,which is larger than that of other typical 2D saturable absorber(SA)materials(graphene,black phosphorus,and MoS_(2))under similar experimental conditions.Based on these findings,using 1T-TaS_(2) as a new SA,passively Q-switched laser operations are successfully performed at 1.06,1.34,and 1.94μm.The results highlight the promise of 1T-TaS_(2) for broadband optical modulators and provide a potential candidate material system for mid-IR nonlinear optical applications.

Afterglow Carbon Dots:From Fundamentals to Applications

The ability of carbon dots(CDs)to emit afterglow emission in addition to fluorescence in response to UV-to-visible excitation allows them to be a new class of luminescent materials.When compared with traditional organic or inorganic afterglow materials,CDs have a set of advantages,including small size,ease of synthesis,and absence of highly toxic metal ions.In addition,high dependence of their afterglow color output on temperature,excitation wavelength,and aggregation degrees adds remarkable flexibility in the creation of multimode luminescence of CDs without the need for changing their intrinsic attributes.These characteristics make CDs particularly attractive in the fields of sensing,anticounterfeiting,and data encryption.In this review,we first describe the general attributes of afterglow CDs and their fundamental afterglow mechanism.We then highlight recent strategic advances in the generation or activation of the afterglow luminescence of CDs.Considerable emphasis is placed on the summarization of their emergent afterglow properties in response to external stimulation.We further highlight the emerging applications of afterglow CDs on the basis of their unique optical features and present the key challenges needed to be addressed before the realization of their full practical utility.

Gut commensal metabolite rhamnose promotes macrophages phagocytosis by activating SLC12A4 and protects against sepsis in mice

Sepsis progression is significantly associated with the disruption of gut eubiosis.However,the modulatory mechanisms of gut microbiota operating during sepsis are still unclear.Herein,we investigated how gut commensals impact sepsis development in a pre-clinical model.Cecal ligation and puncture(CLP)surgery was used to establish polymicrobial sepsis in mice.Mice depleted of gut microbiota by an antibiotic cocktail(ABX)exhibited a significantly higher level of mortality than controls.As determined by metabolomics analysis,ABX treatment has depleted many metabolites,and subsequent supplementation with L-rhamnose(rhamnose,Rha),a bacterial carbohydrate metabolite,exerted profound immunomodulatory properties with a significant enhancement in macrophage phagocytosis,which in turn improved organ damage and mortality.Mechanistically,rhamnose binds directly to and activates the solute carrier family 12(potassium-chloride symporter),member 4(SLC12A4)in macrophages and promotes phagocytosis by activating the small G-proteins,Ras-related C3 botulinum toxin substrate1(Rac1)and cell division control protein 42 homolog(Cdc42).Interestingly,rhamnose has enhanced the phagocytosis capacity of macrophages from sepsis patients.In conclusion,by identifying SLC12A4 as the host interacting protein,we disclosed that the gut commensal metabolite rhamnose is a functional molecular that could promote the phagocytosis capacity of macrophages and protect the host against sepsis.