Acetyl-L-carnitine protects adipose-derived stem cells exposed to H2O2 through regulating AMBRA1-related autophagy

The cell activity of adipose-derived stem cells(ADSCs)is affected by the intracellular reactive oxygen species(ROS)and the level of autophagy.Previous studies reveal that acetyl-L-carnitine(ALC)possesses capacities of resisting oxidative stress and regulating autophagy.Activating molecule in Beclin1-regulated autophagy protein 1(AMBRA1)plays a key role in initiating Beclin1-regulated autophagy.In the present study,we discovered ALC pretreatment(1 mM,24 h)significantly increased the activity of ADSCs exposed to H_(2)O_(2)(100μM,2 h)in vitro with improved stemness,and reduced the production of intracellular ROS.In addition,we found for the first time that ALC treatment up-regulated autophagy of ADSCs through strengthening the expressions of Beclin1 and AMBRA1 synchronously,which might be involved in the protective effect of ALC.

DL-Serine covalently modified multinuclear lanthanide-implanted arsenotungstates with fast photochromism

A series of DL-serine covalently modified multinuclear lanthanide implanted arsenotungstates K_(2)[{Ln(H_(2)O)_(7)}_(2){As_(4)W_(44)O_(137)(OH)_(18)(H_(2)O)_(2)(DL-Ser)_(2)}{Ln_(2)(H_(2)O)_(5)(DL-Ser)}_(2)]·65H_(2)O(DL-Ser=DL-serine,Ln=La(1),Ce(2),Pr(3))are obtained.Crystal structure analysis shows that these compounds are isomorphic and contain the basic[{As_(4)W_(44)O_(137)(OH)_(18)(H_(2)O)_(2)(DL-Ser)_(2)}{Ln_(2)(H_(2)O)_(5)(DL-Ser)}_(2)]^(8–)polyoxoanion constituted by two{As_(2)W_(19)O_(59)(OH)_(8)(H_(2)O)}^(6–)subunits,a[W_(6)O_(2)_(3)(OH)_(2)(DL-Ser)_(2)]_(14)–fragment,and two embedded[Ln_(2)(H_(2)O)_(5)(DL-Ser)]^(5+)groups,which further build into one dimensional linear chainlike structure via two peripheral Ln^(3+)ions.Most remarkably,these compounds exhibit rapid photochromic behaviors,which changed color quickly from white(1),yellow(2),green(3)to blue(1),brown(2)and glaucous(3)in ten minutes under UV irradiation,and that the colors gradually recovered in the dark for approximately 22 h.

Ln-substituted polytungstates as efficient hetergeneous catalysts for Knoevenagel condensation reaction

Three isomorphic polytungstates,CsgK_(18)H_(10){[Sm_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))3]_(2)(N(CH_(2)PO_(3))_(2))}:46.5H_(2)O(1),CS_(10)K_(9)H_(18){[Eu_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)0_(33))_(3)]_(2)(N(CH_(2)PO_(3))_(2))}.41.5H_(2)O(2),Cs_(10)K_(9)H_(18){[Gd_(2)(H_(2)O)_(4)W_(4)O_(10)(AsW_(9)O_(33))_(3)]_(2)(N(CH_(2)PO_(3))_(2))}:46H_(2)O(_(3)),have been successfully synthesized and characterized by routine methods,and demonstrated excellent catalytic activities in Knoevenagel condensation reaction as heterogeneous catalysts.Notably,catalyst 1 achieved higher reaction activity than catalysts 2 and 3,where a satisfactory reaction yield(95%)and high TON value(6380)could be obtained at moderate reaction condition.In addition,in the scale-up experiment,with the help of catalyst 1,7.8g benzaldehyde and 5.7g ethyl cyanoacetate could transform into corresponding condensation product with a satisfactory yield(83%)and impressive TON value(13.883).

Self-assembly of DNA molecules at bio-interfaces and their emerging applications for biomedicines

Interfacial assembly has been intensively investigated in fabricating biomaterials and nanodevices for various applications.Recently,due to the precise sequence programmability,unique molecular recognition ability,and good biocompatibility,deoxyribonucleic acid(DNA)has been explored as superior building blocks to assemble at bio-interface for manipulating biological entities.To the best of our knowledge,the advances in this area have not been systematically summarized.To provide an overview of the area,in this review,the recently developed DNA assembly strategies on bio-interfaces were well summarized,and their representative works are exampled to illustrate how to rationally and elaborately design DNA molecules to realize functional integration and emerging of novel biological functionalities with high controllability and programmability.Furthermore,the biomedical applications of DNA assembly at bio-interface are categorially elaborated.The fascinating and unique advantages of DNA assembly systems are fully discussed in the exemplified applications to show the distinguished perspective of DNA in the future development.At the end of this review,the current limitations and challenges in applications and potential improvement strategies for DNA assembly at bio-interface are fully discussed.The future development direction is deliberated.We envision that this review will help scientists in the interdisciplinary fields gain a more comprehensive understanding of the DNA assembly at bio-interface,and therefore jointly promote the advances in this field.

有机膦酸构筑的多钨氧簇稀土化合物的设计合成、结构及性质

在常规水溶液条件下,选择介稳态的前驱体K14[As2W19O67(H2O)]与配体羟基乙叉二膦酸(HEDP)及稀土化合物反应,合成了一例有机膦酸构筑的多钨氧簇稀土化合物Cs H[Pr(H2O)4(AsW9O33)(W2O3)(O3PCOHCH3PO3)Pr(H2O)7]2?19H2O(1),并通过单晶X射线衍射分析、元素分析、傅里叶红外光谱分析等对其结构进行了表征.晶体解析表明,化合物1由1个S形结构框架{[(As W9O33)(W2O3)]2}, 2个有机磷酸基团{O3PCOHCH3PO3}和4个Pr3+离子通过一定的方式键连形成三维框架结构.磁学性质研究表明,化合物1呈现出反铁磁性耦合作用.荧光性质研究表明,化合物1在近红外区呈现出双寿命发光,其中τ1=4.76μs(35.53%),τ2=9.71μs(64.4%).

Construction of one Ru_(2)W_(12)-cluster and six lacunary Keggin tungstoarsenate leading to the larger Ru-containing polyoxometalate photocatalyst

Construction of two Ru^(Ⅲ)cations and six lacunary Keggin fragments resulted in a novel Ru_(2)W_(12)-cluster{(RuO_(6))_(2)(WO_(3))_(12)(H_(2)O)_(12)}bridged polyoxometalate,NaH_(11)[(RuO_(6))(AsW_(9)O_(33))_(3){(W_(6)O_(3))(H_(2)O)_(6)}]_(2)53H_(2)O(NaH_(11)·1·53H_(2)O),which represent the largest cluster in all the Ru-containing polyoxometalates.The most interesting characteristic is that the symmetry-related Ru_(2)W_(12)-cluster-based hexamers contain two windmill-shaped[(RuO_(6))(AsW_(9)O_(33))_(3){(W_(6)O_(3))(H_(2)O)_(6)}]trimers or the Ru_(2)W_(12) cluster was tightly wrapped by six segments of B-β-AsW_(9)O_(33).The other remarkable feature is that there have one intriguing cubane structure:which is composed of the Ru(1,2)and W(1,28,50,51,52,53)atoms.The oxygenation reactions of anilines to azoxybenzenes was evaluated when NaH_(11)·1·53H_(2)O served as effective catalyst by probing various reaction.The inherent redox property of oxygen-rich polyoxometalate surfaces and high photocatalytic activity of the Ru-containing metal cluster imbedded in NaH_(11)·1·53H_(2)O provide sufficient driving force for the photocatalytic transformation from anilines to azoxybenzenes.The oxidation of anilines can be realized with higher selectivity to afford various azoxybenzene compounds.The durability test shows that Ru-doping catalyst displays excellent chemical stability during the photocatalytic process.

Synthesis,structure and properties of three novel transition-metal-containing tantalum-phosphate clusters

Peroxide ligation of aqueous metal-oxo clusters provides rich speciation and structural diversity.Here,three novel transition-metal derivatives of polyoxometalate anions,[Ni_(2)(H_(2)O)_(10){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(6-)(1a),[Zn(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(2a)and[Cd(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(3a),have been successfully synthesized by adopting a one-pot reaction strategy.All of these hexatantalates are built from a new-type phosphorus-incorporated hexatantalates.We investigated the solution behaviors,and the peak assignments of the MS spectra indicated some degree of stability of them in water.Furthermore,the proton-conducting ability of compound 1a was also explored and it has shown well conductivity at high relative humidities,with conductivity achieved 1.22×10^(-3) S/cm(85℃,90%RH).

Evaluation of several recently developed sampling strategies within the coarse pixel scale for validation of coarse-resolution satellite albedo products

Due to the spatial heterogeneity and the spatial scale mismatch between in situ and satellite-based measurements,optimal ground sampling should be made to increase the representativeness of in situ observations. Therefore,many ground sampling strategies have been proposed,but their performance within the coarse pixel has not been evaluated. Hence,this study evaluated four typical methods regarding their ability to obtain pixel scale ground ‘truth’. Random combination (RC) performs best,with the always fewest samples to satisfy representativeness errors (REs) of 3% in the case of a small number of samples. When the goal of sampling is to obtain in situ measurements with REs close to 0 at the expense of increasing the number of samples,cumulative representativeness sampling (CRS) is more effective than RC in less heterogeneous areas. Geo-statistical model-based sampling (GSS) does not work well because the number of samples within the coarse pixel scale cannot support a robust semi-variogram model. Stratified sampling (SS) is highly dependent on spatial heterogeneity and does not work well in the case of small sample sizes. This study gives important guidance for ground sample deployment within the coarse pixel for validation of coarse-resolution satellite albedo products over a heterogeneous surface.