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It is a challenge to achieve flexibility in purely inorganic piezoelectric materials without organic support, and various thin film flexible inorganic piezoelectric materials has been developed recently. In this work, lead zirconate titanate (PZT) nanofiber membranes were prepared by electrospinning, and a flexible membranes can be obtained by reducing the calcination temperature, and the flexibility was characterized by the three-point method. The fiber membrane was relatively thicker in relative to thin films and confirmed to adsorb Congo Red quickly under the action of ultrasound. The maximum adsorption capacity is 61.78 mg g−1 and saturation time reaches 20 min under ultrasound treatment. In addition, the color change after saturation adsorption can quickly determine the actual load of the fiber membrane. In the future, this load saturation effect can be used to calibrate the relationship between the piezoelectric signal and the adsorption load, so as to obtain more accurate chemical sensors.

Nanoscale metal-organic frameworks (nMOFs) are a unique type of hybrid materials, which are broadly applicable as cargo delivery systems. However, the relatively low material stability and insufficient cancer cell interacting capacity have limited nMOFs' applications in cancer theranostics. Herein, a zirconium-based nMOF UiO-66-N3 was synthesized, and its surface was covalently functionalized with alkyne-containing polyethylene glycol (PEG) via the azide-alkyne click chemistry. After that, F3 peptide was attached for targeting of cancer cells (the material was denoted as UiO-66-PEG-F3). Doxorubicin (DOX) served as a therapeutic drug and a fluorescent label in this study, and it was transported into UiO-66-PEG conjugates with sufficient drug loading efficiency. pH-responsive release of DOX from UiO-66 conjugates was witnessed. The structural integrity of UiO-66-N3 was maintained post the surface modification process. Flow cytometry and confocal fluorescence microscopy revealed that DOX/UiO-66-PEG-F3 had stronger accumulation in MDA-MB-231 cells (nucleolin+) compared with DOX/UiO-66-PEG. In order to track the pharmacokinetic behavior (organ distribution profile) in vivo, the positron-emitting zirconium-89 (89Zr) was incorporated into UiO-66-N3. Similar PEGylation and F3 peptide conjugation resulted in the formation of 89Zr-UiO-66-PEG-F3. Serial positron emission tomography (PET) imaging demonstrated that the preferential accumulation of 89Zr-UiO-66-PEG-F3 in MDA-MB-231 tumors, and their liver clearance was faster than PEGylated UiO-66 using noncovalent methods. Thus, the PEGylated nMOFs using covalent strategies may find broad application in future cancer theranostics.

For a period of time, the O2 cathode has been the focus of research, while the study of lithium anodes and their interactions is quite rare in rechargeable lithium–oxygen (Li–O2) batteries. Actually, the unstable interface between a Li metal anode and the electrolyte in the presence of O2 will eventually lead to battery failure. It was proposed that lithium nitrate (LiNO3), a well-known stabilizing additive being able to form a passivation solid–electrolyte interphase (SEI) on the Li metal surface, could be introduced into the electrolyte of Li–O2 batteries to improve their performance. Nevertheless, the effective utilization of LiNO3 in this system has heretofore been limited due to the dissolution of NO2− species, one of the components of the SEI, as well as O2 corrosion issues on the Li metal side, thus resulting in unstable cycling of Li–O2 batteries. Herein, by combining the electrochemical polishing technology with the LiNO3 reduction chemistry, we construct on a Li metal surface a stable molecularly smooth SEI which possesses a unique multi-layered structure that encapsulates the soluble NO2− species inside the inner layer. Such an SEI film can not only avoid the negative effects caused by the dissolution of NO2−, but also effectively suppress the dendrite growth on and the O2 permeation to the Li surface. Consequently, the cycle lives of O2-saturated symmetric Li cells and Li–O2 batteries are both improved substantially. Our work offers an effective strategy to protect Li metal anodes in Li–O2 batteries, and meantime, provides a novel insight into the rational utilization of electrolyte additives.

Jing-Bo Liu,1 Qiao-Jun Zhang,2 Jian-Zhi Liu,1 Wen-Ting Zhang,3 Yi Li,3 Hao-Hong Li,3 Zhi-Rong Chen,3 Da-Li Zheng2 1Department of Otorhinolaryngology, Fujian Medical University Union Hospital, Fuzhou, Fujian 350001, People’s Republic of China; 2Fujian Key Laboratory of Oral Diseases, Fujian Biological Materials Engineering and Technology Center of Stomatology, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, Fujian 350004, People’s Republic of China; 3College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, People’s Republic of ChinaCorrespondence: Da-Li ZhengFujian Key Laboratory of Oral Diseases, Fujian Biological Materials Engineering and Technology Center of Stomatology, School and Hospital of Stomatology, Fujian Medical University, 88 Jiaotong Road, Fuzhou 350004, People’s Republic of ChinaTel +86-591-83720599Email dalizheng@fjmu.edu.cnJian-Zhi LiuDepartment of Otorhinolaryngology, Fujian Medical University Union Hospital, 29 Xinquan Road, Fuzhou 350001, People’s Republic of ChinaTel +86-591- 83357896Email liujianzhi@aliyun.comBackground: The realization of multifunction in one bulk material is fascinating for developing a new generation of devices. Quaternary phosphorus salts were seldom utilized as templates in haloargentate systems, and the hybridization of alkyl(triphenyl)phosphonium with halometallate will be a good strategy for the development of multifunctional material, especially for biological material.Methods: Under the template of (triphenyl)phosphonium-based quaternary phosphorus salts with different spacer lengths (n=2, 3, 4), three bromoargentate hybrids were constructed via the solution method, ie, (1,2-DBTPP)(Ag2Br4) ( 1), {(1,3-DBTPP)2(Ag7Br11)]∙CH3CN∙H2O}n ( 2), and {[(1,4-DBTPP)(Ag5Br7)](CH3CN)2∙H2O}n ( 3) (1,2-DBTPP2+=ethane-1,2-diylbis (triphenyl)phosphonium, 1,3-DBTPP2+=propane-1,3-diylbis (triphenyl)phosphonium, 1,4-DBTPP2+=butane-1,4-diylbis (triphenyl)phosphonium)).Results: The (Ag7Br11)n4n- chain in 2 is a new type of 1-D bromoargentate chain constructed from cubane-like Ag4Br4 nodes, AgBr4 tetrahedrons and AgBr3 triangles. Interestingly, by elongating spacer n from 2 to 4, argentophilicity interactions are weakened, and the hydrogen bonds are strengthened. Consequently, their water stabilities and photocurrents are improved, in which the Ag-4d/Br-4p to π* anti-bonding orbital of the quaternary phosphorus transfer is facilitated. Furthermore, the greenish blue emissions can be detected. Finally, high inhabitation rates against Streptococcus mutans and Candida albicans can be observed in 2 and 3.Conclusion: In all experiments, by elongating the spacer lengths of quaternary phosphorus salts, multifunctions were integrated in the quaternary phosphorus/bromoargentate hybrids, including greenish blue luminescence, repeatable photocurrent responses and durable antimicrobial activities with enhanced water stability. This work could provide a theoretical guide for the design of new biologically multifunctional materials.Keywords: quaternary phosphorus, bromoargentates, nanoparticles, luminescence, antimicrobial

The hybridization of 1,4-bis(isoquinoline)butane (BIQBT2+) cation with iodobismuthate under different solvents produce two isomers α-[(BIQBT)(BiI4)2]n (α-1, in CH3OH/H2O mixed solvent, Triclinic system with P-1 space group) and β-[(BIQBT)(BiI4)2]n (β-1, in CH3OH, Monoclinic system with P21/c space group). The 1-D (BiI4) n n− chains are constructed from the opposite edge-sharing BiI6 octahedra. The (BIQBT)2+ in α-isomer adopts the planar configuration, and that in β-isomer presents the chair-like configuration, as a result, different packing modes (intercalating quasi-3-D mode for α-1 and interlocking 2-D mode for β-1) are observed. Interestingly, from α-1 to β-1, distortion degree of BiI6 octahedron and π–π stacking interaction decrease, but hydrogen bonds number increase. Consequently, due to different packing mode, photoluminescence/thermochromisms can be found in α-1, but those of β-1 are vanished, Theoretical calculation was conducted to disclose the structure/thermochromism correlation.

The salt-tolerant unicellular alga Dunaliella bardawil FACHB-847 can accumulate large amounts of lutein, but the underlying cause of massive accumulation of lutein is still unknown. In this study, genes encoding two types of carotene hydroxylases, i.e., β-carotene hydroxylase (DbBCH) and cytochrome P450 carotenoid hydroxylase (DbCYP97s; DbCYP97A, DbCYP97B, and DbCYP97C), were cloned from D. bardawil. Their substrate specificities and enzyme activities were tested through functional complementation assays in Escherichia coli. It was showed that DbBCH could catalyze the hydroxylation of the β-rings of both β- and α-carotene, and displayed a low level of e-hydroxylase. Unlike CYP97A from higher plants, DbCYP97A could not hydroxylate β-carotene. DbCYP97A and DbCYP97C showed high hydroxylase activity toward the β-ring and e-ring of α-carotene, respectively. DbCYP97B displayed minor activity toward the β-ring of α-carotene. The high accumulation of lutein in D. bardawil may be due to the multiple pathways for lutein biosynthesis generated from α-carotene with zeinoxanthin or α-cryptoxanthin as intermediates by DbBCH and DbCYP97s. Taken together, this study provides insights for understanding the underlying reason for high production of lutein in the halophilic green alga D. bardawil FACHB-847.

Alkaline direct hydrazine (N2H4) fuel cells (DHFCs) are considered one of the most promising liquid-fed fuel cells because of their high energy density, high theoretical voltage, and zero carbon dioxide (CO2) emissions. However, the lack of a suitable electrolyte membrane impedes the further development of alkaline DHFC. Herein, a potassium hydroxide (KOH)-doped polybenzimidazole (PBI) membrane is applied in alkaline DHFCs, and the detailed operating conditions are investigated for the first time. With optimal KOH and N2H4 concentrations in the anolyte, membrane thickness, and cathode gas humidity, the DHFC gives a peak power density of 0.708 W cm−2. The results of this study demonstrate the promising application of PBI membranes in DHFC and provide a platform to evaluate the performance of catalysts synthesized for DHFC.

Considering the low conversion and long reaction time in scaling up reaction in batch reactor, the organocatalyzed epoxidation reaction of styrene was intensified under continuous flow conditions using a commercial fluidic reactor (Corning Advanced Flow G1 Reactor). After investigating the effect of reaction temperature, catalyst amount, MeCN/t-BuOH ratio, FO/FAB (buffer solution amount), total feed flow rate and operating mode on the epoxidation reaction, the optimal reaction conditions were identified under continuous flow conditions. Upon optimization, high conversion and excellent selectivity with short reaction time (3.17 min) can be obtained. We successfully developed a process for the rapid and continuous epoxidation of styrene using an organocatalyst with hydrogen peroxide as the oxidant. Compared with the batch conditions, the continuous flow reactor can exhibit unique advantages including high-speed, safety, continuousness and absence of amplifying effect, which will be significant for the industrial production of epoxides.

The design of single-component broadband photoemitters with high stability is imperative for the development of next-generation WLEDs. In this work, 1D cationic haloplumbate chains and rigid luminescent naphthalene dicarboxylate (2,6-ndc) with a larger conjugated system were used to construct crystalline single-component broadband photoemitters, i.e. formulated as [(Pb4X2)(ndc)4·A2]n (X = Cl, Br, and I, A = (CH3)3NH+ and (CH3)2NH2+). These hybrids are 3D networks built from flexible 1D cationic (Pb4X2)6+ chains and rigid 2,6-naphthalene dicarboxylic acid ligands. The variation of halogen atoms from Cl to Br/I with higher polarity can switch the holo-directed geometry to the hemi-directed geometry with different distorted degrees. The larger conjugated system of 2,6-ndc leads to strong individual blue adsorptions and emissions. In particular, the Br- and I-analogues with hemi-directed geometries can give rise to additional red emissions, corresponding to the presence of stereochemical activities of Pb centers. Consequently, Br- and I-analogues are white-light emitters containing red emissions stemming from deformable haloplumbate and blue emissions originating from luminescent naphthalene motifs. Interestingly, haloplumbate-based emissions are thermally tunable, and those of naphthalene are generally inactive to thermal stimulus. As a result, tunable emissions from blue/white to yellow can be achieved. The higher quantum yield of Br-analogues can be assigned to their worse haloplumbate connectivity, which can enhance the electron–phonon coupling. In all, the combination of flexible haloplumbate chains with larger π-conjugated fluorophores is an efficient strategy for the construction of tunable broadband photoemitters.

BackgroundThe cholesterol gallstones diseases (CGD) is highly correlated with metabolic syndrome and type 2 diabetes. The present study aimed to investigate preventive effects of pioglitazone (PIO), an antidiabetic drug, on the CGD in guinea pigs fed with a lithogenic diet (LD).MethodsThe guinea pigs were fed with the LD for 8 weeks. All guinea pigs were grouped as follows: low fat diet; LD; LD plus PIO (4 mg/kg); LD plus PIO (8 mg/kg); LD plus ezetimibe (EZE) (2 mg/kg). Gallbladder stones were observed using microscopy. The profile of biliary composition, and blood glucose, insulin and lipid were analyzed. The liver or ileum was harvested for determinations of hydroxyl-methyl-glutaryl-CoA reductase (HMGCR), sterol regulatory element-binding proteins 2 (SREBP2), 7α-hydroxylase (CYP7A1), adenosine triphosphate-binding cassette (ABC) sterol transporters G5 and G8 (ABCG5, ABCG8), bile salt export pump (BSEP), Niemann-Pick C1-Like 1 (NPC1L1) and acetyl-coenzyme A cholesterol acyltransferase (ACAT2) by Western blot. The gallbladders were used for histological examination.ResultsThe LD successfully induced gallstone. Both pioglitazone and ezetimibe prevented gallstone formation, as well as hepatic and cholecystic damages. Pioglitazone significantly decreased HMGCR and SREBP2, but increased CYP7A1, ABCG5, ABCG8, and BSEP in the liver. Pioglitazone also remarkably decreased NPC1L1 and ACAT2, while increased ABCG5/8 in the intestine. The beneficial alterations of cholesterol and bile acids in the bile, as well as profile of glucose, insulin and lipid in the blood were found in the guinea pigs treated with pioglitazone.ConclusionPioglitazone has a noticeable benefit towards the CGD, which is involved in changes of synthesis, transformation, absorption, and transportation of cholesterol.

The development of new high-density memories that can work in harsh environments such as high temperature and humidity will be significant for some special occasions such as oil and geothermal industries. Herein, a facial strategy for implementing a ternary memory device with high working temperature/humidity was executed. In detail, an asymmetric aggregation-induced-emission active molecule (azobenzol-decorated tetraphenylethylene, i.e., TPE-Azo) was embedded into flexible poly(ethylene-alt-maleic anhydride) (PEM) to prepare a TPE-Azo@PEM composite, which served as an active layer to fabricate the FTO/TPE-Azo@PEM/Ag device. This device can demonstrate excellent ternary memory performances with a current ratio of 1:104.2:101.6 for "OFF", "ON1", and "ON2" states. Specially, it can exhibit good environmental endurance at high working temperature (350 °C) and humidity (RH = 90%). The ternary memory mechanism can be explained as the combination of aggregation-induced current/conductance and conformational change-induced charge transfer in the TPE-Azo molecule, which was verified by Kelvin probe force microscopy, UV-vis spectra, X-ray diffraction, and single-crystal structural analysis. This strategy can be used as a universal method for the construction of high-density multilevel memristors with good environmental tolerance.

Dunaliella salina can accumulate a large amount of β-carotene which is generally considered to be its terminal product of carotenoid metabolism. In this study, it was proved that D. salina has the ketolase (DsBKT) of catalyzing the synthesis of astaxanthin, the downstream products of β-carotene. Therefore, the reason why D. salina does not synthesize astaxanthin is the purpose of this study. The enzymatic activity of DsBKT was detected by functional complementation assays in Escherichia coli, results showed that DsBKT had efficient ketolase activity toward β-carotene and zeaxanthin to produce astaxanthin, indicating that there were complete astaxanthin-producing genes in Dunaliella. Unlike the induced expression of Lycopene cyclase (catalyzing β-carotene synthesis) under salt stress, the expression of DsBKT was very low under both normal and stress conditions, which may be the main reason why D. salina cannot accumulate astaxanthin. On the contrary, with the astaxanthin-rich Haematococcus pluvialis as a control, its BKT gene was significantly upregulated under salt stress. Further study showed that DsBKT promoter had strong promoter ability and could stably drive the expression of ble-egfp in D. salina. Obviously, DsBKT promoter is not the reason of DsBKT not being expressed which may be caused by Noncoding RNA.

With hollow mesoporous silica (hMSN) and injectable macroporous hydrogel (Gel) used as the internal and external drug-loading material respectively, a sequential drug delivery system DOX-CA4P@Gel was constructed, in which combretastatin A4 phosphate (CA4P) and doxorubicin (DOX) were both loaded. The anti-angiogenic drug, CA4P was initially released due to the degradation of Gel, followed by the anti-cell proliferative drug, DOX, released from hMSN in tumor microenvironment. Results showed that CA4P was mainly released at the early stage. At 48 h, CA4P release reached 71.08%, while DOX was only 14.39%. At 144 h, CA4P was 78.20%, while DOX release significantly increased to 61.60%, showing an obvious sequential release behavior. Photodynamic properties of porphyrin endow hydrogel (φΔ(Gel)=0.91) with enhanced tumor therapy effect. In vitro and in vivo experiments showed that dual drugs treated groups have better tumor inhibition than solo drug under near infrared laser irradiation, indicating the effectivity of combined photodynamic-chemotherapy.

The encapsulation of guests into metal-organic frameworks (MOF) is an efficient strategy to generate novel multifunctional materials with enhanced properties. Herein, four halometallate@MOF composites with formulas of {(Pb2I4Br3)[(Pr(bpdo)4(H2O)2]·(H2O)}n (1), {[Pb3I10(H2O)2][Y2(bpdo)5(OH)2]·4(H2O)}n (2), {(Bi2I9)[(Pr(bpdo)3(H2O)]}n (3), {(Bi4I18)[(La(bpdo)4(H2O)2]2}n (4) (bpdo = 4,4'-bipyridine N,N'-dioxide) were prepared. In these composites, lanthanide-viologen MOF act as matrices, whose cavities were penetrated by halometallates. Consequently, the insertion of electron-rich halometallates into electron-deficient lanthanide-viologen matrices leads to the presence of strong room temperature charge transfer (CT) interactions. Importantly, these composites exhibit enhanced photo/thermal stabilities, controllable white emissions, reversible thermochromisms, and good photocurrent response performances. Specially, the memory devices based on these composites illustrate reversible electrical bistability behaviors, which can be assigned to ohmic and space-charge-limited conduction (SCLC) mechanisms. This kind of composite can be utilized as a multifunctional platform with enhanced stability.

A two-step strategy was employed to culture Dunaliella tertiolecta, an oleaginous unicellular green alga, combined by the salt stress and sodium azide intervention, to observe their effects on its lipid accumulation. When the algae cultured at different salt concentrations reached the logarithmic growth phase, sodium azide was added. The results showed that the addition of sodium azide significantly increased the lipid content and had no significant effect on cell biomass. The lipid yield and single cell lipid content under 50 μM sodium azide increased by 10.4% and 21.7%. Under the two-step culture condition, combining of the treatment of 50 μM sodium azide and 2.5 M salt stress, the total lipid productivity and single-cell lipid content were 10% and 70.5% higher than that of the control. It seemed that sodium azide and salinity might have a synergistic effect on the lipid accumulation of D. tertiolecta. It can be concluded that sodium azide is an effective inducer of lipid accumulation in D. tertiolecta, and two-stage cultivation is a feasible way to improve lipid accumulation in microalgae.

Glycerol-3-phosphate (G3P) is the important precursors for triacylglycerol synthesis, while glycerol-3-phosphate dehydrogenase (GPDH) determines the formation of G3P. In this study, two GDPH genes, Dtgdp1 and Dtgdp2 were isolated and identified from Dunaliella tertiolecta. The full-length Dtgdp1 and Dtgdp2 CDS were 2016 bp and 2094 bp, which encoded two putative protein sequences of 671 and 697 amino acids with predicted molecular weights of 73.64 kDa and 76.73 kDa, respectively. DtGDP1 and DtGDP2 both had a close relationship with those of algal and higher plants. DtGDP1 shared two conserved superfamily (A1 and A2) and four signature motifs (I-IV), and the DtGDP2 showed six signature domains (from motif I to VI) and DAO_C conserved family. Our previous work showed that the triethylamine intervention could greatly increase the triacylglycerol content (up to 80%) of D. tertiolecta. This study aims to investigate the effect of triethylamine on GPDH expression. Results showed that, when treated by triethylamine at 100 ppm and 150 ppm, the expression levels of Dtgdp1 and Dtgpd2 were increased to 5.121- and 56.964-fold compared with the control, respectively. Triethylamine seemed to enhance lipid metabolic flow by inducing the expressions of Dtgdp1 and Dtgdp2 to increase the lipid content, which provides a new insight into the desired pathway of lipid synthesis in algae through genetic engineering.

Dendritic cells (DCs) based cancer immunotherapy is largely dependent on adequate antigen delivery and efficient induction of DCs maturation to produce sufficient antigen presentation and ultimately lead to substantial activation of tumor‐specific CD8+ T cells. Carbon nanotubes (CNTs) have attracted great attention in biomedicine because of their unique physicochemical properties. In order to effectively deliver tumor antigens to DCs and trigger a strong anti‐tumor immune response, herein, a specific DCs target delivery system was assembled by using multi‐walled carbon nanotubes modified with mannose which can specifically bind to the mannose receptor on DCs membrane. Ovalbumin (OVA) as a model antigen, could be adsorbed on the surface of mannose modified multi‐walled carbon nanotubes (Man‐MWCNTs) with a large drug loading content. This nanotube‐antigen complex showed low cytotoxicity to DCs and was efficiently engulfed by DCs to induce DCs maturation and cytokine release in vitro, indicating that it could be a potent antigen‐adjuvant nanovector of efficient antigen delivery for therapeutic purpose.

Accumulating evidence has shown that tauroursodeoxycholic acid (TUDCA) is neuroprotective in different animal models of neurological diseases. However, whether TGR5 agonist TUDCA can improve lipopolysaccharide (LPS)-induced cognitive impairment in mice is less clear. Using a model of cognitive impairment with LPS (2.0 μg) we investigated the effects of TUDCA (200 or 400 μg) on cognitive dysfunction and neurotoxicity in mice. Both Morris water maze and Y-maze avoidance tests showed that TUDCA treatment significantly alleviated LPS-induced behavioral impairments. More importantly, we found that TUDCA treatment reversed TGR5 down-regulation, prevented neuroinflammation via inhibiting NF-κB signaling in the hippocampus of LPS-treated mice. Additionally, TUDCA treatment decreased LPS-induced apoptosis through decreasing TUNEL-positive cells and the overexpression of caspase-3, increasing the ratio of Bcl-2/Bax. TUDCA treatment also ameliorated synaptic plasticity impairments by increasing the ratio of mBDNF/proBDNF, the number of dendritic spines and the expression of synapse-associated proteins in the hippocampus. Our results indicated that TUDCA can improve cognitive impairment and neurotoxicity induced by LPS in mice, which is involved in TGR5-mediated NF-κB signaling.

The neurotoxicity of Aβ peptides has been well documented, but effective neuroprotective approaches against Aβ neurotoxicity are unavailable. In the present study, we investigated effects of 1-Methylnicotinamide (MNA), known as a main metabolite of nicotinamide (NA), on the impairment of learning and memory induced by Aβ and the underlying mechanisms. We found that intragastric administration of MNA at 100 or 200 mg/kg for 3 weeks significantly reversed bilateral intrahippocampal injection of Aβ1–42-induced cognitive impairments in the Morris water maze (MWM), Y-maze and Novel object recognition tests. Furthermore, MNA suppressed Aβ1–42-induced neuroinflammation, characterized by suppressed activation of microglia, decreased the expression of IL-6, TNF-α and nuclear translocation of NF-κB p65, as well as attenuated neuronal apoptosis as indicated by decreased TUNEL-positive cells and ratio of caspase-3 fragment to procaspase-3, and increased ratio of Bcl-2/Bax in the hippocampus. Our results show that MNA may ameliorate Aβ1–42-induced cognition deficits, which is involved in inhibition of neuroinflammation and apoptosis mediated by NF-κB signaling, suggesting that MNA could have potential therapeutic value for AD.

Photon-recycling effects improve radiative efficiencies of semiconductor materials and play important roles in the design of high-performance optoelectronic devices. Conventional research mostly st...

Redox mediators (RMs) are widely applied in lithium–oxygen (Li–O2) batteries since they offer an alternative way to avoid the direct electrochemical oxidization of Li2O2 during charging, and thus greatly reduce the charge overpotential. Unfortunately, the defenseless Li–metal anode is severely corroded by the oxidized RMs shuttled from the cathode side, resulting in the low utilization of RMs and poor cycling stability. Herein, a functionalized double-guaranteed NPG membrane with electrostatic repulsion and steric hindrance characteristics is proposed to suppress the shuttle effect of LiI RM. Benefiting from the interaction between the O atoms in PEO and the sulfonic acid groups in Nafion and the two-dimensional skeleton structure of graphene, Nafion, PEO and graphene can couple with each other, forming a large network barrier with multi-functional properties. As expected, the LiI-based Li–O2 batteries with the NPG membrane exhibited a smooth, iodine-free Li anode surface after many cycles and delivered an ultrahigh discharge capacity of ∼26 917 mA h g−1 at a current density of 200 mA g−1 and ultralong cycle life (472 cycles) at 500 mA g−1 with a cutoff capacity of 500 mA h g−1, which are far better than that of the bare batteries.

Peroxisome proliferator-activator receptor (PPAR) γ is a nuclear hormone receptor that regulates glucose homeostasis, lipid metabolism, and adipocyte function. It has been shown that activation of PPARγ can reduce the incidence of gallstone. Herein we aimed to clarify the role of PPARγ in the reduction of gallstones. The plasmid containing the coding sequence of PPARγ was constructed and transfected in the human liver cell line (L02 cells). Western blot and RT-PCR were used to detect hydroxyl-methyl-glutaryl-CoA reductase (HMGCR), sterol regulatory element-binding proteins 2 (SREBP2), 7α-hydroxylase (CYP7A1), adenosine triphosphate-binding cassette (ABC) sterol transporters G5 and G8 (ABCG5, ABCG8) and liver X receptor α (LXRα). The Amplex Red cholesterol assay kit was used to detect the intracellular or extracellular cholesterol level. Our data showed that PPARγ overexpression caused significant decreases in both extracellular and intracellular cholesterol in the L02 cells. The further studies indicated PPARγ overexpression substantially decreased expression of HMGCR and SREBP-2, increased expression of CYP7A1, ABCG5, ABCG8 and LXRα. These results indicated that upregulation of PPARγ may reduce cholesterol levels through multiple-pathways including HMGCR/SREBP2-mediated biosynthesis, CYP7A1-mediated transformation, and ABCG5/ABCG8-mediated efflux. We thus suggest that PPARγ might have beneficial effects for cholesterol gallstones diseases. Keywords: PPARγ, Cholesterol, HMGCR, CYP7A1 and ABCG5/8

The combination of hexacyanoferrate anions with protonated N,N′-dipyridyl-naphthalene diimide tectons resulted in a novel cuboid 3-D H-bonded anion-coordinated framework. Induced by anion–π interactions, such a unique framework is further catenated into an unprecedented five-fold interpenetrated D–A hybrid heterostructure with 1-D hexacyanoferrate polyanions and naphthalene diimide aggregates as electron donors and acceptors, respectively. The photophysical and photochemical properties have also been discussed.

Objectives Cognitive impairment is the main character of Alzheimer's disease (AD). This study mainly focused on whether mogrol, a tetracyclic triterpenoids compound of Siraitia grosvenorii Swingle, can ameliorate the memory impairment induced by Aβ1–42. Methods Memory impairment mice model was made by stereotactic intra-hippocampal microinjection of Aβ1–42 (410 pm/mouse). Mogrol (20, 40, 80 mg/kg) was given to mice by intragastric administration at 3 days after Aβ1–42 injection for totally 3 weeks. Morris water maze test and Y-maze test were operated to evaluate the therapeutic effect of morgrol on Aβ1–42-induced memory impairments. Immunohistochemical analyses and Hoechst 33258 assay were used to evaluate effect of morgrol on Aβ1–42-induced microglia overactivation and apoptotic response in hippocampus of mice. Western blotting assay was used to evaluate effect of mogrol on the Aβ1–42-activated NF-κB signaling. Key findings Mogrol could significantly alleviate Aβ1–42-induced memory impairments, inhibit Aβ1–42-induced microglia overactivation and prevent Aβ1–42-triggered apoptotic response in the hippocampus. Mogrol also could suppress Aβ1–42-activated NF-κB signaling, reduce the production of proinflammatory cytokines. Conclusions This study suggested that mogrol would ameliorate the memory impairment induced by Aβ1–42, which is involved in anti-inflammation and anti-apoptosis in the brain.

Two novel heterometallic organic frameworks built from trinuclear indium and cuprous halide clusters, [(In3O)2(Cu2I2)3(ina)12(H2O)6](NO3)2·7DMA·10H2O (1) and [NH2(CH3)2][In3(OH)2(H2O)2(ina)8(Cu4I4)2]·5DMA·8H2O (2), where Hina = isonicotinic acid, have been successfully constructed with the orientation of the ina ligand. 1 shows a fascinating highly porous honeycomb-like 3D cationic framework with a trigonal-bipyramid-type cage based on a planar [In3O(CO2)6]+ trimer and a rhombohedral Cu2I2 cluster. Comparably, 2 displays a 3D negative network with irregular hexagonal channels constructed from a [In3(OH)2(CO2)8]- trimer and a cubane-like Cu4I4 cluster. Especially, 1 displays a reversible I2 adsorption/release performance with high adsorption capacity, whose mechanism has been disclosed by theoretical simulation. Also, the green/red emission of 2 stems from iodocuprate centers with quenched indium-centered emission.

Two-dimensional (2D) transition metal dichalcogenides (TMDs), with their atomic thicknesses, high carrier mobility, fast charge transfer, and intrinsic spin-valley couplings, have been demonstrated one of the most appealing candidates for next-generation electronic and optoelectronic devices. The synthesis of TMDs with well-controlled crystallinity, quality and composition is essential to fully realize their promising applications. Similar to that in III-V semiconductor synthesis, the precise precursor supply is a precondition for controllable growth of TMDs. Although great efforts have been devoted to modulate the transition metal supply, few effective methods of chalcogen feeding control were developed. Herein we report a strategy of using active chalcogen monomer supply to grow TMDs and their alloys in a robust and controllable manner. It is found that at a high temperature, the active chalcogen monomers (such as S, Se, Te atoms or their mixtures) can be controllably released from metal chalcogenides and, thus, enable the synthesis of TMDs (MX2, M = Mo, W; X = S, Se, Te) with very high quality, e.g., MoS2 monolayers exhibit photoluminescent circular helicity of ~92%, comparable to the best exfoliated single-crystal flakes and close to the theoretical limit of unity. More intriguingly, a uniform quaternary TMD alloy with three different anions, i.e., MoS2(1-x-y)Se2xTe2y, was accomplished for the first time. Our mechanism study revealed that the active chalcogen monomers can bind and diffuse freely on a TMD surface, which enables the effective nucleation and reaction, quick chalcogen vacancy healing, and alloy formation during the growth. The chalcogen monomer supply strategy offers more degrees of freedom for the controllable synthesis of 2D compounds and their alloys, which will greatly benefit the development of high-end devices with desired 2D materials.

The urokinase plasminogen activator (uPA) and its cofactors are important regulators of tumor initiation and progression (including metastasis), and its overexpression is associated with unfavorable situations in cancer patients. We have previously used positron emission tomography (PET) imaging with a radiolabeled monoclonal antibody against the uPA (named ATN-291) to detect the uPA signaling activity in various cancer types; however, good tumor contrast can only be observed 24 h postinjection. To shorten the antibody circulation time and decrease interactions of ATN-291 with the mononuclear phagocyte system (MPS), our goal in this study is to develop an engineered antibody fragment (F(ab')2) from the parent antibody. By pepsin digestion and chromatography purification, ATN-291 F(ab')2 was obtained and characterized. Subsequently, it was conjugated with NOTA-Bn-NCS or fluorescein isothiocyanate (FITC) for PET imaging and fluorescence-mediated cellular analysis (i.e., flow cytometry or fluorescence microscopy). We confirmed that ATN-291 F(ab')2 still maintained a good targeting efficacy for the uPA in MDA-MB-231 cells (uPA+) and it had a faster blood clearance speed compared with ATN-291, while its interaction with MPS has been significantly decreased. In rodent tumor xenografts, radiolabeled ATN-291 F(ab')2 had a selective and persistent uptake in MDA-MB-231 tumors, with an early tumor-to-blood ratio of 1.3 ± 0.8 (n = 4) at 2 h postinjection from PET imaging. During our observation, radiolabeled ATN-291 F(ab')2 was excreted from both renal and hepatobiliary pathways. Radiolabeled ATN-291 F(ab')2 was also used for detecting uPA fluctuation during the tumor treatment in test animals. We concluded that radiolabeled ATN-291 F(ab')2 could be used as fast as PET cancer diagnostics with versatile applicability.

In this paper, a three-dimensional (3D) microtubular reduced graphene oxide (rGO) FET sensor, decorated with silver nanoparticles (Ag NPs) has been fabricated and demonstrated for NO 2 detections. The performance of our planar 2D sensor and 3D microtubular sensors with different numbers of winding were compared and contrasted. The preliminary results shown that our 3D microtubular Ag NPs/rGO FET sensor with 2 windings exhibits a sensor response of 8.17 % to 10 part per million (ppm) NO 2 at room temperature. This 3D microtubular concept and study provide a new approach for highly integrated and miniaturized hazardous gases sensing applications for health and safety detections, environmental monitoring and beyond.

Cellular RNA polymerases can become trapped on DNA or RNA, threatening genome stability and limiting free enzyme pools, or enter dormancy. How RNA polymerase recycling into active states is achieved and balanced with quiescence remains elusive. We structurally analyzed Bacillus subtilis RNA polymerase bound to the NTPase HelD. HelD has two long arms: a Gre cleavage factor-like coiled-coil inserts deep into the RNA polymerase secondary channel, dismantling the active site and displacing RNA; a unique helical protrusion inserts into the main channel, prying β and β’ subunits apart and dislodging DNA, aided by the δ subunit. HelD release depends on ATP, and a dimeric structure resembling hibernating RNA polymerase I suggests that HelD can induce dormancy at low energy levels. Our results reveal an ingenious mechanism by which active RNA polymerase pools are adjusted in response to the nutritional state.

Epidemiological studies have corroborated that respiratory diseases, including lung cancer, are related to fine particulate matter (&lt, 2.5 &mu, m) (PM2.5) exposure. The toxic responses of PM2.5 are greatly influenced by the source of PM2.5. However, the effects of PM2.5 from Beijing on bronchial genotoxicity are scarce. In the present study, PM2.5 from Beijing was sampled and applied in vitro to investigate its genotoxicity and the mechanisms behind it. Human bronchial epithelial cells 16HBE were used as a model for exposure. Low (67.5 &mu, g/mL), medium (116.9 &mu, g/mL), and high (202.5 &mu, g/mL) doses of PM2.5 were used for cell exposure. After PM2.5 exposure, cell viability, oxidative stress markers, DNA (deoxyribonucleic acid) strand breaks, 8-OH-dG levels, micronuclei formation, and DNA repair gene expression were measured. The results showed that PM2.5 significantly induced cytotoxicity in 16HBE. Moreover, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and cellular heme oxygenase (HO-1) were increased, and the level of glutathione (GSH) was decreased, which represented the occurrence of severe oxidative stress in 16HBE. The micronucleus rate was elevated, and DNA damage occurred as indicators of the comet assay, &gamma, H2AX and 8-OH-dG, were markedly enhanced by PM2.5, accompanied by the influence of 8-oxoguanine DNA glycosylase (OGG1), X-ray repair cross-complementing gene 1 (XRCC1), and poly (ADP-ribose) polymerase-1 (PARP1) expression. These results support the significant role of PM2.5 genotoxicity in 16HBE cells, which may occur through the combined effect on oxidative stress and the influence of DNA repair genes.

The reactions of AgSCN with excess KSCN in the presence of linear viologens templates afford seven new hybrids, {(MV)[Ag4(SCN)6]}n (1), {(MV)[Ag2(SCN)4]}n (2), {(EV)[Ag4(SCN)6]}n (3), {(EV)[Ag2(SCN...

Due to the excellent photoluminescent properties and singlet oxygen (1O2) generating efficiency, graphene quantum dots (GQDs) with maximal emission in near-infrared region (NIR) exhibited great potential in cancer imaging and therapy. However, GQDs can be cleared quickly via the renal system in vivo because of their ultrasmall size, which leads to the compromised cancer cell killing efficacy. Here, we report a hybrid nanoplatform, where GQDs were incorporated into the cavity of hollow mesoporous silica nanoparticles (hMSN) to form GQDs@hMSN-PEG nanoparticles (NPs). Optical characterization indicated that GQDs@hMSN-PEG NPs still maintained good absorption and emission properties from GQDs, and the composite NPs still possessed similar 1O2 generating efficiency. GQDs@hMSN-PEG NPs exhibited good biocompatibility in vitro and in vivo. High cargo-loading efficiency was achieved for doxorubicin (DOX), and the formed GQDs@hMSN(DOX)-PEG NPs showed the feasibility of tumor-oriented drug delivery. The extended retention time in tumor and good drug loading efficacy confirmed that GQDs@hMSN-PEG could serve as one promising candidate for combinational cancer treatment where photodynamic therapy and chemotherapy modules can be integrated into one system.

Dendritic Pt nanostructures were prepared through electrodeposition on a substrate Pt electrode by applying square-wave potential method. It has been found that the as-prepared dendritic Pt nanostructure exhibited enhanced IR absorption with an enhancement factor up to 10 folds for adsorbed CO species. Such an enhanced in-situ FTIR spectroscopy (FTIRS) has been applied in studies of reaction mechanism of ammonia electrooxidation. From in-situ FTIR spectra recorded during ammonia electrooxidation, two characteristic IR bands at 1430 cm− 1 and between 1227 and 1250 cm− 1 were observed at low potential region (E 0.10 V vs. SCE), two IR bands at 2231 cm− 1 and 1236 cm− 1 were observed and ascribed respectively to N2O and NO2− species, which are the ultimate oxidation products detected under present investigation conditions. In addition to in-situ FTIR spectroscopy, online electrochemical mass spectroscopy (OEMS) was used to detect volatile products. The clear OEMS signals of m/e = 30 and m/e = 46 measured at potentials above − 0.5 V and − 0.30 V, respectively, indicate the production of N2 (IR inactive) and confirm the generation of N2O. Based on results of cyclic voltammetry, in-situ FTIRS and OEMS, the reaction mechanism is therefore elucidated with molecular details of intermediates and products involved in ammonia electrooxidation in alkaline solutions.

Reactive oxygen species (ROS) and glutathione (GSH) dual responsive nanoparticulate drug delivery systems (nano-DDSs) hold great promise to improve the therapeutic efficacy and alleviate the side effects of chemo drugs in cancer theranosis. Herein, hydrogen peroxide (H2O2) and GSH dual responsive thioketal nanoparticle (TKN) was rationally designed for paclitaxel (PTX) delivery. Compared to other stimuli-sensitive nano-DDSs, this dual responsive DDS is not only sensitive to biologically relevant H2O2 and GSH for on-demand drug release but also biodegradable into biocompatible byproducts after fulfilling its delivering task. Considering the heterogeneous redox potential gradient, the PTX loaded TKNs (PTX-TKNs) might first respond to the extracellular ROS and then to the intracellular GSH, achieving a programmable release of PTX at the tumor site. The selective toxicity of PTX-TKNs to tumor cells with high levels of ROS and GSH was verified both in vitro and in vivo.

Owing to high specific capacity of ∼250 mA h g-1, lithium-rich layered oxide cathode materials (Li1+ xNi yCo zMn(3- x-2 y-3 z)/4O2) have been considered as one of the most promising candidates for the next-generation cathode materials of lithium ion batteries. However, the commercialization of this kind of cathode materials seriously restricted by voltage decay upon cycling though Li-rich materials with high cobalt content have been widely studied and show good capacity. This research successfully suppresses voltage decay upon cycling while maintaining high specific capacity with low Co/Ni ratio in Li-rich cathode materials. Online continuous flow differential electrochemical mass spectrometry (OEMS) and in situ X-ray diffraction (XRD) techniques have been applied to investigate the structure transformation of Li-rich layered oxide materials during charge-discharge process. The results of OEMS revealed that low Co/Ni ratio lithium-rich layered oxide cathode materials released no lattice oxygen at the first charge process, which will lead to the suppression of the voltage decay upon cycling. The in situ XRD results displayed the structure transition of lithium-rich layered oxide cathode materials during the charge-discharge process. The Li1.13Ni0.275Mn0.580O2 cathode material exhibited a high initial medium discharge voltage of 3.710 and a 3.586 V medium discharge voltage with the lower voltage decay of 0.124 V after 100 cycles.

This work shows the solar-driven dehydrogenative coupling of methane to ethane at room temperature. A solar-to-C2H6 energy conversion efficiency of 0.08% was achieved on the polar surface of Au/ZnO porous nanosheets (NSs), where methane C–H bonds are polarized and dissociated by the local electric field normal to the polar {001} plane, and finally converted into ethane and hydrogen through a radical coupling pathway. Mechanistic studies suggest that the Au-plasmon-induced resonance energy transfer modulates charge carrier energetics to trigger the stoichiometric conversion. Hot electrons reduce protons to H2, which is the rate-determining step of methane coupling.

By using squarates as coordination building units, six new complexes formulated as [Mg(C4O4)(H2O)2]n (1), [Pr2(C4O4)2(OA)(H2O)4]n (2), [Eu2(C4O4)3(H2O)8]n (3) [Cd2(C4O4)2(bpdo)(H2O)4]n (4), [Cd(C4HO4)2(H2O)4]·(MV)2·(C4O4)2 (5), and [Cd(C4HO4)2(H2O)4]·(EV)·(C4HO4)2 (6), where (C4O4)2− = squarate, OA = oxalic acid, MV = methyl viologen, EV = ethyl viologen, and bpdo = 4,4′-dipyrdiyl-N,N′-dioxide, have been synthesized under hydro/solvothermal conditions. They present structural dimensions from 3-D networks (1, 2), 2-D layers (3, 4) to 0-D clusters (5, 6) based on the versatile bridged modes of squarates and the introduction of second ligands. In particular, 5 and 6 are the first examples incorporating squarates (electronic-rich species) with viologens (electronic-poor species) in one lattice. Consequently, they exhibit not only photocurrent responses but also reversible thermochromism, which will be beneficial for the design of multi-functional materials.

The mono-substituted bipyridinium derivative 1-(3-carboxybenzyl)-4,4′-bipyridinium (cbpy) and polyiodide were adopted to construct two new lead-carboxylate hybrids: [Pb(cbpy)I3·I3]n (1) and {[Pb(cbpy)2](I3)4·I2}n (2), in which interesting halogen bonds were detected. Specifically, the hybrids demonstrate efficient photocatalytic degradation of organic dyes and excellent photocurrent response, and the mechanisms of degradation have been discussed and verified using theoretical calculations.

The receptor for advanced glycation end products (RAGE) at the blood-brain barrier (BBB) is critical for regulation of amyloid-β (Aβ) homeostasis in the diabetic brain. In this study, we used an in vitro BBB model consisting of mouse brain capillary endothelial cells (MBCECs) to investigate whether advanced glycation end products (AGEs) increase Aβ influx transport across the BBB and the underlying mechanisms. We found that AGEs induced Aβ influx transport across the BBB in concentration- and time-dependent manner, accompanied by increased RAGE expression and nuclear factor-kappa B p65 (NF-κB p65), and decreased nuclear peroxisome proliferator-activated receptor γ (PPARγ). Blockade of RAGE with its antibody and inhibition of NF-κB signaling with PDTC as well as activation of PPARγ with rosiglitazone significantly decreased Aβ transport across the BBB from the periphery to the brain. These treatments also pronouncedly suppressed AGEs-induced increases in RAGE expression and nuclear NF-κB p65 and reversed the decrease in nuclear PPARγ. These results suggest that RAGE-NF-κB-PPARγ signaling is involved in regulation of AGEs-induced influx transport of Aβ across the BBB and targeting the signaling pathway could serve as a novel strategy to modify such Aβ transport.

The dilational properties of anionic gemini surfactants alkanediyl-α,ω-bis(m-octylphenoxy sulfonate) (C8CmC8) with polymethylene spacers at the water–air and water–decane interfaces were investigat...

A series of stable phosphonium salts have been synthesized via a novel four-component reaction of an arene nucleophile, 2-heteroatom substituted aryl aldehyde, and phosphine in presence of an acid. The phosphonium salts thus obtained were utilized for the synthesis of a variety of bis-heteroarenes, providing an efficient alternative method to the classical cross-coupling strategies.

Nanoscale metal–organic frameworks (nMOF) materials represent an attractive tool for various biomedical applications. Due to the chemical versatility, enormous porosity, and tunable degradability of nMOFs, they have been adopted as carriers for delivery of imaging and/or therapeutic cargos. However, the relatively low stability of most nMOFs has limited practical in vivo applications. Here we report the production and characterization of an intrinsically radioactive UiO-66 nMOF (89Zr-UiO-66) with incorporation of positron-emitting isotope zirconium-89 (89Zr). 89Zr-UiO-66 was further functionalized with pyrene-derived polyethylene glycol (Py–PGA-PEG) and conjugated with a peptide ligand (F3) to nucleolin for targeting of triple-negative breast tumors. Doxorubicin (DOX) was loaded onto UiO-66 with a relatively high loading capacity (1 mg DOX/mg UiO-66) and served as both a therapeutic cargo and a fluorescence visualizer in this study. Functionalized 89Zr-UiO-66 demonstrated strong radiochemical and material stability in different biological media. Based on the findings from cellular targeting and in vivo positron emission tomography (PET) imaging, we can conclude that 89Zr-UiO-66/Py–PGA-PEG-F3 can serve as an image-guidable, tumor-selective cargo delivery nanoplatform. In addition, toxicity evaluation confirmed that properly PEGylated UiO-66 did not impose acute or chronic toxicity to the test subjects. With selective targeting of nucleolin on both tumor vasculature and tumor cells, this intrinsically radioactive nMOF can find broad application in cancer theranostics.

High overexpression of sigma (σ) receptors (σ1 and σ2 subtypes) in a variety of human solid tumors has prompted the development of σ receptor-targeting radioligands, as imaging agents for tumor detection. A majority of these radioligands to date target the σ2 receptor, a potential marker of tumor proliferative status. The identification of approximately equal proportions of both σ receptor subtypes in prostate tumors suggests that a high affinity, dual σ receptor-targeting radioligand could potentially provide enhanced tumor targeting efficacy in prostate cancer. To accomplish this goal, we designed a series of ligands which bind to both σ receptor subtypes with high affinity. Ligand 3a in this series, displaying optimal dual σ receptor subtype affinity (σ1, 6.3 nM; σ2, 10.2 nM) was radiolabeled with fluorine-18 (18F) to give [18F]3a and evaluated as a σ receptor-targeting radioligand in the mouse PC-3 prostate tumor model. Cellular assays with PC-3 cells demonstrated that a major proportion of [18F]3a wa...

Four mononuclear Cu(i)-halide complexes containing phosphines and pyridine ligands with strong electron donor substituents, [CuCl(PPh3)2(4-NMe2py)] (1), [CuI(PPh3)2(4-NH2py)] (2), [CuI(POP)(4-NH2py)] (3), and [CuI(POP)(4-NMe2py)]·0.5(Et2O) (4), (PPh3 = triphenylphosphine, 4-NMe2py = 4-(dimethylamino)pyridine, POP = bis[(2-diphenyl-phosphino)phenyl]ether, 4-NH2py = 4-aminopyridine, Et2O = diethyl ether) were synthesized and studied with regard to their structural, photophysical properties and theoretical calculations. The complexes exhibit pure blue thermally activated delayed fluorescence (λmax = 442 (1), 436 (2), 464 (3), and 448 nm (4)) in crystalline at room temperature. Emission lifetime analyses and density functional theory (DFT) calculations show that the blue-light emission at room temperature is the singlet (metal + halide)-to-ligand charge transfer state, (1(M + X)LCT), while that at 77 K is the state of 3(M + X)LCT transition character, owing to the small singlet-triplet energy gaps (ΔE = 660-1680 cm-1). X-ray diffraction structure analysis, photophysical studies and theoretical calculations suggest that the much larger torsion angle between the N-heterocyclic rings and N-Cu-X planes of complex 3 than that of 1, 2 and 4 might causes the bathochromic shift of luminescence, although these complexes containing similar heterocycle ligands.

Strain serves as a powerful freedom to effectively, reversibly, and continuously engineer the physical and chemical properties of two-dimensional (2D) materials, such as bandgap, phase diagram, and reaction activity. Although there is a high demand for full characterization of the strain vector at local points, it is still very challenging to measure the local strain amplitude and its direction. Here, we report a novel approach to monitor the local strain vector in 2D molybdenum diselenide (MoSe2) by polarization-dependent optical second-harmonic generation (SHG). The strain amplitude can be evaluated from the SHG intensity in a sensitive way (−49% relative change per 1% strain); while the strain direction can be directly indicated by the evolution of polarization-dependent SHG pattern. In addition, we employ this technique to investigate the interlayer locking effect in 2H MoSe2 bilayers when the bottom layer is under stretching but the top layer is free. Our observation, combined with ab initio calculat...

Graphitic carbon nitride (g-CN) nanosheets (CNNs) with an ultra-high quantum yield (80.1%) ultraviolet fluorescence (FL) were prepared. The effects of the lateral size and the polymerization temperature on the optical properties of CNNs have been studied. The ultraviolet FL was proved to have originated from the isolated melem units according to the density functional theory calculation and mass spectra. The obtained CNNs are further used as a pH probe due to the dependence of the FL signal on the pH of the solution.

Metallofullerenes have attracted considerable attention as potential novel noninvasive high-relaxivity magnetic resonance contrast agents. However, the applications of metallofullerenes as stimuli-responsive biosensors to monitor biological processes are still scarce. Herein, manganese-fullerenes core-shell nanocomposites are prepared via a facile one-pot approach to achieve GSH-activatable magnetic resonance/fluorescence bimodal imaging functions. The nanocomposites initially have a FRET-induced quenched fluorescence, and water-resisting stimulated low T1-MRI contrast. Upon exposure to GSH, collapse of the outer MnO2 shell led to reconstruction of the nanoprobes and subsequently resulted in multicolor fluorescence recovery and longitudinal (T1) relaxivity enhancement (r1 value up to 29.8 mM-1 s-1 at 0.5 T based on Mn ion). Our work demonstrates feasibility of using fullerenes to fabricate activatable probes for molecular imaging of GSH, which may promote the development of new fullerene-based stimuli-responsive multimodal probes for the detection and regulation of particular biological processes in vivo.

Donor–acceptor (D–A) hybrid heterostructures are an emerging class of hybrid complexes with potential applications in current optoelectronic technologies. To achieve high photoinduced charge-carrier generation and separation in a heterostructure, a common strategy is the fabrication of continuous or bicontinuous structures by the crystallization of semiconductive donor and acceptor tectons at the molecular level. So far, only a few such heterostructures have been fabricated, most of which involve unstable and narrow band gap metal halides. In this paper, we extended these unique hybrid heterostructures to continuous alkaline-earth metal oxide clusters. The combination of the naphthalene diimide (NDI) tecton bearing four carboxylates at two extremities with Ca2+ (or Sr2+) cations led to two isostructural D–A hybrid heterostructures with infinite 1-D carbon-doped alkaline-earth metal oxide clusters and X-aggregated NDI dimers as electron donors and acceptors, respectively. Due to the different metal cations in inorganic clusters, they exhibited diametrically opposite photochromic sensitivities and photocatalytic activities. To better rationalize them, a plausible photoinduced electron transfer process for the D–A hybrid heterostructures with photoactive acceptors has been developed.

Adiponectin is an adipokine that has recently been under investigation for potential neuroprotective effects in various brain disorders including Alzheimer's disease, stroke, and depression. Adiponectin receptors (AdipoR1 and AdipoR2) are found throughout various brain regions, including the hippocampus. However, the role of these receptors in synaptic and cognitive function is not clear. Therefore, the goal of the current study was to evaluate synaptic and cognitive function in the absence of adiponectin. The current study utilized 12-month-old adiponectin knockout (APN-KO) mice and age-matched controls to study cognitive and hippocampal synaptic alterations. We determined that AdipoR1 and AdipoR2 are present in the synaptosome, with AdipoR2 displaying increased presynaptic vs. postsynaptic localization, whereas AdipoR1 was enriched in both the presynaptic and postsynaptic fractions. APN-KO mice displayed cognitive deficits in the novel object recognition (NOR) and Y-maze tests. This was mirrored by deficits in long-term potentiation (LTP) of the hippocampal Schaefer collateral pathway in APN-KO mice. APN-KO mice also displayed a reduction in basal synaptic transmission and an increase in presynaptic release probability. Deficits in LTP were rescued through hippocampal slice incubation with the adiponectin receptor agonist, AdipoRon, indicating that acute alterations in adiponectin receptor signaling influence synaptic function. Along with the deficits in LTP, altered levels of key presynaptic and postsynaptic proteins involved in glutamatergic neurotransmission were observed in APN-KO mice. Taken together, these results indicate that adiponectin is an important regulator of cognition and synaptic function in the hippocampus. Future studies should examine the role of specific adiponectin receptors in synaptic processes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper