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A cyber physical distribution power system (CPDS) is a large and complex infrastructure that coordinates the cyber communication system and the physical distribution power system. Because of the increasingly advanced information communication technology, the development of cyber physical distribution power system has caused key cyber security issues related to system operation. This paper is focused on realizing a unified system attack modeling and security assessment of an active distribution power system. In this paper, first we present an overview of the system operation from the fusion system perspective. The significant effects of network intrusion attacks on operational security are evaluated. A new unified cyber physical network model is established using a limited stochastic Petri net graph theory that considers refined firewalls and password components. Then, a security effectiveness evaluation method is proposed to analyze channel throughput variation and system robustness. Overall CPDS security risk values are determined based on physical influence coefficients. Finally, simulations of an improved IEEE-33 bus distribution power system and security assessment under intrusion attacks are described. The research work could raise awareness of the cyber intrusion threats and provide the basis for security defense.

Rationale: Mutations in KIT, a major cancer driver gene, are now considered as important drug targets for the treatment of melanomas arising from mucosal and acral tissues and from chronically sun-damaged sites. At present, imatinib is the only targeted drug for KIT-mutation-bearing melanomas that is recommended by the National Comprehensive Cancer Network (NCCN) Clinical Practice guidelines. Patients with KIT mutations, however, are either insensitive or rapidly progress to imatinib insensitivity, which restricts its clinical use. Thus, effective inhibitors of KIT-mutation-bearing melanomas are urgently needed. Methods: A cohort of patient-derived tumor xenograft (PDX) models and corresponding PDX-derived cells (PDCs) from patients with melanomas harboring KIT mutations (KITV560D, KITK642E and KITD816V) were established, characterized, and then used to test the in vitro and, subsequently, in vivo inhibitory effects of a panel of known KIT inhibitors. Results: Ponatinib was more potent than imatinib against cells bearing KIT mutations. In vivo drug efficacy evaluation experiments showed that ponatinib treatment caused much stronger inhibition of KIT-mutation-bearing melanomas than did imatinib. Mechanistically, molecular dynamics (MD) simulations revealed a plausible atomic-level explanation for the observation that ponatinib has a higher affinity for the KITD816V mutant protein than does imatinib. Conclusions: Our study of KIT-mutation-and KITWT-bearing melanomas demonstrates that ponatinib is a far more potent inhibitor than is imatinib for KIT-mutation-bearing melanomas and thus underscores that ponatinib should be given priority consideration for the design of precision treatments for melanoma patients triaged to have KIT mutations. Moreover, our work provides a rationale for undertaking clinical trials to examine the repurposing of ponatinib, which is already approved for use in leukemia, for use in treating a large subset of melanoma patients.

Herein, we have demonstrated that the plasma-exfoliation of CoOOH nanolayers (∼8 nm) into an ultrathin structure (∼2 nm) could significantly improve the PEC activities of BiVO4 photoanodes. A photocurrent density of 4.9 mA cm−2 and a charge separation efficiency of 89% have been achieved at 1.23 VRHE under AM 1.5G illumination, which are more than two-fold higher than those of pristine CoOOH/BiVO4 photoanodes.

Although various photothermal therapy (PTT) nanoagents have been developed in recent years, the rational design and easy synthesis of a PTT nanoplatform with improved near-infrared (NIR) absorption have remained challenging. Herein, via a facile one-pot solvothermal strategy, hydrophilic nanosheet-assembled flower-like Fe7S8/Bi2S3 superstructures were fabricated successfully. Such nanoflowers exhibit improved NIR absorption, which is 1.54 times higher than that of pure Bi2S3 nanosheets at a wavelength of 808 nm. Attractively, these nanoflowers could serve as a drug delivery carrier with controlled release under pH/NIR stimuli and display a fascinating chemo-photothermal synergetic therapeutic effect both in vitro and vivo. The resulting nanoflowers may open up a way for the design of other nanoagents with an improved NIR absorption and chemo-photothermal cancer therapy effect.

The experimental investigation of charge transport through an individual molecular junction provides a unique opportunity to reveal its distinctive quantum interference (QI), which is of fundamental importance for the development of novel molecular devices such as high on/off ratio switches and thermoelectric applications. In this review, we discuss the fundamentals of QI and the corresponding single-molecule experimental techniques. We start from the investigation of the QI of cross-conjugated systems to polycyclic aromatic hydrocarbons (PAHs) with different connectivities, then discuss σ-interference molecules and even supramolecular systems. Further, we review the latest applications of QI in single-molecule switches and summarize the recent developments of single-molecule electrochemical transistors reported by three different research groups by taking advantage of the energy level dependence of QI.

Janus heterostructural materials as photothermal agents with enhanced optical conversion capability are promising for artery inflammation treatment by the hyperthermia of macrophages, a primordial part in the artery inflammation response that can deteriorate into atherosclerosis and even break the vessels. Herein, a synthesis route of Janus Ag/Ag2S beads with hydrophilic ligands has been developed with a precise control over concentration, time and surface functionalization. These Ag/Ag2S heterodimers show desirable sizes of around 90 nm in diameter, in which Ag nanocrystals have a diameter of around 25 nm, and they exhibit a photothermal conversion efficiency of up to 50.0% as well as relatively low biotoxicity and good biocompatibility. Importantly, the as-prepared Janus Ag/Ag2S beads with a high biological safety can be effectively swallowed by macrophages and have a remarkable benefit of eliminating these cells from the original state of artery inflammation through the excellent photothermal effect of this material, without causing any further damage to the arteries and major organs in vivo. This study further promotes the development of treatment for vascular inflammation by the photothermal melting of macrophage cells in intima environments.

Hourly concentrations of water-soluble inorganic ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3- and SO42-) in PM2.5 and related reactive gases were measured with a Gas and Aerosol Collector combined with Ion Chromatography (GAC-IC) in urban Chengdu from April 17 to May 27, 2017, during which both haze and dust episodes occurred frequently. Nitrate was the most abundant ion in PM2.5 and substantially increased during haze pollution with the NO3-/SO42- mass ratio increasing from 0.78 during clean period to 1.1 during haze period. Aerosols in Chengdu were generally ammonium-rich, wherein ammonium nitrate was primarily formed through homogeneous gas-phase reactions and limited by the availability of HNO3, indicating that preferentially reducing the emissions of NOx could make for mitigating spring haze pollution in Chengdu. Backward trajectory clustering coupled with measured species and a potential source contribution function (PSCF) for PM2.5, PM10/PM2.5, sulfate, nitrate, ammonium, and Ca2+ indicated that regionally transported pollutants from the southern and southeastern Sichuan Basin strongly contributed to springtime PM2.5 pollution in Chengdu, but long-distance transport from northwestern China also contributed to dust pollution. Moreover, the treatment of urban fugitive dust in southern Sichuan is also important for reducing coarse particles in Chengdu. Therefore, the improvement of air quality in Chengdu, even in the Sichuan Basin, requires the regional joint emission reduction of particles and gaseous precursors across the entire Sichuan Basin, especially for cities located in southeastern Sichuan Basin.

Controlling ammonia (NH

High ozone concentrations promote the formation of nitrate in the nocturnal residual layer (RL), but this phenomenon has not been confirmed by direct observation. In this study, ozone, water-soluble ions in PM2.5 and the corresponding meteorological factors in the stable boundary layer, RL and mixing layer were observed by portable instruments carried on a tethered balloon over the North China Plain. The ozone concentration significantly increased in the RL compared to that in the stable boundary layer, while particulate nitrate significantly decreased, except in the clouds. Unfavorable environmental conditions, i.e., high temperature, low relative humidity, low aerosol surface area, and weak particle acidity, are not conducive to dinitrogen pentoxide uptake and hydrolysis to form particulate nitrate in the RL, and are conducive to the volatilization of nitrate to a gaseous state. Thus, our observations differed from traditional reports and confirmed that the morning peak of particulate nitrate at ground level is not related to the downward transport of nitrate from the RL. In addition, evidence for nitrate formation in cloudy weather is provided, and the possible impact on ozone is discussed.

Background & Aims Fibrosis in the liver is the main histological determinant of non-alcoholic steatohepatitis (NASH), a disease that parallels the worldwide surge in metabolic syndromes. Currently, there is no effective treatment for liver fibrosis. While Hippo/YAP (Yes-associated protein) signaling is essential for liver regeneration, its aberrant activation frequently leads to fibrosis and tumorigenesis. Unravelling “context-specific” contributions of YAP in liver repair might help selectively bypass fibrosis and preserve the pro-regenerative YAP function in hepatic diseases. Methods We used murine liver fibrosis and minipig NASH models, liver biopsies from cirrhotic patients, single-cell RNA sequencing (scRNA-Seq) and a G-protein-coupled receptor (GPCR) ligand screening system. Results YAP levels in macrophages are increased in the livers of humans and mice with liver fibrosis. The fibrogenic role of macrophage YAP was evidenced via boosting type I interferon and attenuating liver fibrosis in mice specifically lacking Yap1 in myeloid cells. scRNA-Seq further showed that defecting YAP pathway in macrophages diminished a fibrogenic vascular endothelial cell subset exhibiting pro-fibrotic molecular signatures such as CTGF and VCAM1 expression. To specifically target fibrogenic YAP in macrophages, we utilized a GPCR ligand screening system and identified a dopamine receptor D2 (DRD2) antagonist that selectively blocked YAP in macrophages but not hepatocytes. Genetic and pharmacological targeting of macrophage DRD2 attenuated liver fibrosis. In a large animal (minipig) NASH model recapitulating human pathology, DRD2 antagonist blocked fibrosis and restored hepatic architecture. Conclusions DRD2 antagonization selectively targets YAP-dependent fibrogenic crosstalk between macrophages and CTGF+VCAM1+ endothelial cells, promoting liver regeneration over fibrosis in both rodent and large animal models. Lay summary Fibrosis in the liver is one of the main histological determinants of non-alcoholic steatohepatitis (NASH), a disease paralleling a worldwide surge in metabolic syndromes. Our study demonstrates that myeloid-specific YAP deficiency attenuates liver fibrosis. Dopamine receptor D2 (DRD2) antagonization selectively blocks YAP in macrophages and thwarts liver fibrosis in both rodent and large animal models, showing the potential for the GPCR targeting-based NASH therapies.

The oncoprotein N‑Myc has a carcinogenic effect in numerous types of cancer, and it can cause castration resistance in prostate cancer (PCa), and leads to the development of small cell neuroendocrine cancer by regulating multiple target genes. Immunohistochemical staining, RT‑qPCR, western blotting, wound healing and CCK‑8 assays were used to detect the expression of N‑Myc and FSCN1 as well as AR and CgA at the human level and cell level. The immunohistochemical results revealed that the protein levels of N‑Myc proto‑oncogene protein (N‑Myc) and fascin (FSCN1) in PCa were significantly higher than that of hyperplastic tissues (P

A ratiometric fluorescent aptasensor based on energy transfer between [Ru(bpy)3]2+ and silica quantum dots (silica QDs) for assaying OTA was fabricated. The aptamer for OTA was used as the gate to shield the fluorescent reagent [Ru(bpy)3]2+ into mesoporous silica nanoparticle (MSN). In the presence of OTA, the constrained [Ru(bpy)3]2+ was released from MSN due to a target-induced aptamer conformational change. The released [Ru(bpy)3]2+ adsorbed onto the negatively charged silica QDs through electrostatic interaction. This creates appearance of fluorescence from [Ru(bpy)3]2+ at 625 nm and decrease of the fluorescence from silica QDs at 442 nm owing to the energy transfer. The value of FL625nm/FL442nm was in proportion to the concentration of OTA in the range 0.5~100 ng mL−1 with a LOD of 0.08 ng mL−1. Practical applicability of this method was validated by the determination of OTA in flour samples.

Following the implementation of the strictest clean air policies to date in Beijing, the physicochemical characteristics and sources of PM

BackgroundThere was little known on how the interaction effect between obesity and current smoking affected the incidence of hypertension. The aim of this study was to investigate how body mass index (BMI) modified the effect of current smoking on the incidence of hypertension.MethodsData were obtained from the China Health and Nutrition Survey (CHNS). According to the WHO recommendations for Chinese people, the normal weight, overweight, and obesity were defined using the BMI cutoff values 18.5 kg/m2, 23.0 kg/m2, and 27.5 kg/m, respectively. Current smokers were defined as having smoked at least 100 cigarettes or electronic cigarettes, 20 cigars, or 20 tobacco pipes and other type of tobacco in the last 30 days preceding the survey. Hypertension was defined as systolic blood pressure (SBP)/ diastolic blood pressure (DBP) ≥ 140/90 mmHg, use of anti-hypertensive medications, or a self-reported diagnosis.ResultsThis study included 12,900 subjects. There were interaction effects between obesity and current smoking in females (P = 0.030) and the 50–59 years group (P = 0.049). Current smoking was a significant predictor of incident hypertension only in the total and female populations with normal weight (HR: 1.119 and 1.274;HR95%CI: 1.013–1.236 and 1.143–1.415; andP = 0.027 and 0.040, respectively). Stratified by age, current smoking affected the development of hypertension only in the 50–59 years subjects with the normal weight (HR: 1.356;HR95%CI: 1.084–1.697; andP = 0.008).ConclusionsCurrent smoking was a significant predictor of incident hypertension only in the female and middle-age populations with normal weight but not in the overweight and obesity as well as the younger and elder populations.

Manganese (Mn) is an essential element and is required for the virulence of many pathogens. In Bacillus subtilis, Mn(II) homeostasis is regulated by MntR, a Mn(II)-responsive, DNA-binding protein. MntR serves as both a repressor of Mn(II) uptake transporters and as a transcriptional activator for expression of two cation diffusion facilitator Mn(II) efflux pumps, MneP and MneS. Mutants lacking either mntR or both mneP and mneS are extremely sensitive to Mn(II) intoxication. Using transposon mutagenesis to select suppressors of Mn(II) sensitivity, we identified YceF, a TerC family membrane protein, as capable of providing Mn(II) resistance. Another TerC paralog, YkoY, is regulated by a Mn(II)-sensing riboswitch and is partially redundant in function with YceF. YkoY is regulated in parallel with an unknown function protein YybP, also controlled by a Mn(II)-sensing riboswitch. Strains lacking between one and five of these known or putative Mn(II) tolerance proteins (MneP, MneS, YceF, YkoY, and YybP) were tested for sensitivity to Mn(II) in growth assays and for accumulation of Mn(II) using inductively coupled plasma mass spectrometry. Loss of YceF and, to a lesser extent, YkoY, sensitizes cells lacking the MneP and MneS efflux transporters to Mn(II) intoxication. This sensitivity correlates with elevated intracellular Mn(II), consistent with the suggestion that TerC proteins function in Mn(II) efflux. IMPORTANCE Manganese homeostasis is primarily regulated at the level of transport. Bacillus subtilis MntR serves as a Mn(II)-activated repressor of importer genes (mntH and mntABC) and an activator of efflux genes (mneP and mneS). Elevated intracellular Mn(II) also binds to Mn-sensing riboswitches to activate transcription of yybP and ykoY, which encodes a TerC family member. Here, we demonstrate that two TerC family proteins, YceF and YkoY, help prevent Mn(II) intoxication. TerC family proteins are widespread in bacteria and may influence host-pathogen interactions, but their effects on Mn(II) homeostasis are unclear. Our results suggest that TerC proteins work by Mn(II) export under Mn(II) overload conditions to help alleviate toxicity.

As one of the important components of PM2.5, elemental carbon (EC) particles could quickly mix with other organic or inorganic species after entering the atmosphere, which directly affected its climate and environmental effects and impact on human health. In order to study the mixture and evolution of EC particles in the atmosphere, this study used single particle aerosol mass spectrometry to measure the EC-containing particles in three winters (2016/17, 2018/19 and 2019/20) in Chengdu, one of the most polluted megacities in China. The results showed that the average mass concentrations of PM2.5 in the three winters were 121 ± 58 μg m−3, 90 ± 32 μg m−3 and 79 ± 38 μg m−3, respectively, and the mass ratios of PM2.5/PM10 were 0.71, 0.78 and 0.78, respectively. EC-containing particles accounted for 40.7%–54.7% of all particles and could be divided into six categories: EC-dust (EC-D), fresh EC (ECf), EC-organic carbon (EC-OC), EC-nitrate (EC-N), EC-sulfate (EC-S) and EC-sulfate-nitrate (EC-SN). From winter 2016/17 to 2019/20, the contributions of EC-N and EC-OC particles increased, while the contributions of EC-S and EC-SN particles decreased. Meanwhile, EC-N particles became increasingly important for the formation of heavy pollution. Photochemical and liquid-phase processes dominated the formation of EC-N and EC-S particles, respectively, while the dominant formation mechanism of EC-SN particles changed from photochemical to liquid-phase processes from winter 2016/17 to 2019/20. Total EC and EC-S particles in Chengdu were mainly transported from the east and southeast areas to Chengdu, while ECf particles mainly derived from local emissions. Compared with the previous two winters, the potential source areas of the EC-containing particles in winter 2019/20 reduced significantly. These findings provide new insight into the atmospheric behavior of urban particles and are important reference for the study of EC particles in other regions in the world, especially in urban areas.

In this work, Cu2ZnSnS4 (CZTS) thin film was successfully prepared from four types of mixed binary sulfides nanoparticles under inert Ar atmosphere. A comparison study was conducted to explore the effect of binary sulfides with different value states on the CZTS thin films. Through X-ray diffraction (XRD), Raman and scanning electron microscopy (SEM), the pure CZTS phase can be obtained independent of the value states. However, distinguished crystallinity and morphology of CZTS were observed by using binary precursor with different value states. The grain size up to 1 µm was achieved by annealing (Cu2S+ZnS+SnS2) precursor without additional sulfur atmosphere, suggesting that value state of binary sulfides precursor play an important role in CZTS growth. This result also agrees well with our theoretical prediction. Finally, appropriate ratio of Cu/Zn/Sn was evidenced to yield an enhancement in power conversion efficiency from 0.09% (stoichiometric ratio) to 0.55% (Cu-poor, Zn-rich).

The development of simple, fast and sensitive aptasensor for OTA plays an important role in food safety due to its severe toxicity. In this research, taking advantage of the intrinsic peroxidase-like activity of g-C3N4 nanosheet (g-CNNS) and its high affinity toward signal-strand DNA, a label-free electrochemical OTA aptasensor was fabricated. There is an outstanding property that the aptasensor did not require labeled aptamer and immobilization of g-CNNS compared with previous g-CNNS-based aptasensors. The presence of OTA induced the conformational change of the aptamer, and then g-CNNS noncovalently assembled with the free complementary strand on the electrode via π-π interaction. The captured g-CNNS catalyzed the oxidation of H2O2 to amplify current signal. As a result, this aptasensor realized the detection limit of 0.073 nM, and was also employed to assay OTA in the real samples, including red wines, juices and corns. More importantly, the development of this label-free electrochemical aptasensor opens up the application of g-CNNS as the peroxidase-mimicking DNAzyme.

A Single Particle Aerosol Mass Spectrometer (SPAMS) was deployed in the urban area of Chengdu to investigate the size-resolved chemical composition and mixing state of single particles from 22 September to 26 October 2016. Ten major single particle types were resolved with the ART-2a algorithm and these types were classified into carbonaceous particles, secondary inorganic particles, and other particles. The mixing state analysis showed that carbonaceous and other particles were commonly internally mixed with sulfate and nitrate by atmospheric processes. Carbonaceous particles were mainly internally mixed with sulfate, while other particle types were mixed with nitrate. The abatement of NOx concentrations is essential for the reduction of PM2.5 (particles with the aerodynamic diameter smaller than 2.5 μm) pollution in Chengdu. The complete process of a pollution event can be summarized as regional (clean), local emission (transition), and accumulation of pollutants (polluted). At high relative humidity levels, the aqueous-phase reaction is a key pathway for the formation of PM2.5 species. The diverse emission characteristics of different types of days (weekdays, weekends, and the National Day holiday) resulted in significantly different diurnal patterns in the PM2.5 mass and total number concentrations. The preliminarily formed particles experienced a variety of atmospheric processes (such as coagulation, condensation, and accumulation), which were responsible for the decrease in the number concentration and subsequent high PM2.5 mass concentration values. All these findings provide new insights into, and improved understanding of, the behavior of single particles and the pollution formation mechanisms in the Sichuan Basin.

Gross primary productivity (GPP) is very important in the global carbon cycle. Currently, the newly released estimates of 8-day GPP at 500 m spatial resolution (Collection 6) are provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Science Team for the global land surface via the improved light use efficiency (LUE) model. However, few studies have evaluated its performance. In this study, the MODIS GPP products (GPPMOD) were compared with the observed GPP (GPPEC) values from site-level eddy covariance measurements over seven maize flux sites in different areas around the world. The results indicate that the annual GPPMOD was underestimated by 6%‒58% across sites. Nevertheless, after incorporating the parameters of the calibrated LUE, the measurements of meteorological variables and the reconstructed Fractional Photosynthetic Active Radiation (FPAR) into the GPPMOD algorithm in steps, the accuracies of GPPMOD estimates were improved greatly, albeit to varying degrees. The differences between the GPPMOD and the GPPEC were primarily due to the magnitude of LUE and FPAR. The underestimate of maize cropland LUE was a widespread problem which exerted the largest impact on the GPPMOD algorithm. In American and European sites, the performance of the FPAR exhibited distinct differences in capturing vegetation GPP during the growing season due to the canopy heterogeneity. In addition, at the DE-Kli site, the GPPMOD abruptly produced extreme low values during the growing season because of the contaminated FPAR from a continuous rainy season. After correcting the noise of the FPAR, the accuracy of the GPPMOD was improved by approximately 14%. Therefore, it is crucial to further improve the accuracy of global GPPMOD, especially for the maize crop ecosystem, to maintain food security and better understand global carbon cycle.

Air pollution is a serious global health problem nowadays. So, it is an emergency to pay sufficient attention to treat and prevent the diseases caused by air pollution, especially respiratory disease and lung damage. Cladina rangiferina (L.) Nyl. is an edible lichen that has been used in medicinal diets to treat respiratory and other diseases for over 500 years. In this study, a water-soluble polysaccharide, CRWP-P, was obtained from C. rangiferina by hot-water extraction, freeze-thawing separation, and Fehling reagent purification. Structural analysis showed that CRWP-P is a linear α-(1 → 3),(1 → 4)- d -glucan without branches. Its Mw was determined to be 1.05 × 105 Da. Its (1,3)-α- d -glucopyranosyl: (1,4)-α- d -glucopyranosyl ratio is approximately 1:2. Antioxidant activity assay showed that C. rangiferina polysaccharides, especially CRWP-P, had appreciable DPPH radical-scavenging activity and reducing power. Notably, they could effectively decrease cell breakdown and ROS generation, inhibit lipid peroxidation, increase key antioxidase activity, and promote glutathione redox cycling in Pb2+-oxidative injured A549 alveolar epithelium cells. Overall, the results of this study indicated that C. rangiferina polysaccharides, especially CRWP-P, have the potential to be natural antioxidants for the treatment of lung oxidative damage induced by lead of air pollutants.

To better understand the characteristics of the chemical compositions of aerosols comprised of water soluble ions (WSIs) and carbonaceous aerosol (CA) and their impacts on the visibility throughout the North China Plain (NCP), four experimental sampling campaigns were carried out between June 2013 and May 2014. The sampling sites were located in Beijing, Xiangshan, Tianjin, Shijiazhuang, and Qinhuangdao. The air pollution episodes mainly occurred during the autumn and winter in the NCP. With regard to different particle size distributions, the ratio of anions to cations in the fine size (0.64) was greater than that in the coarse size (0.54) in the NCP. Coefficients of divergence indicate that aerosol pollution had similar characteristics in the five cities of the NCP and that the pollutants were characterized by mutual influences and regional transfer processes. There were different non-linear correlations between the visibility and mass concentrations of PM2.5 at different relative humidity (RH) conditions. When the RH was > 70%, the visibility was < 5 km; this shows that, due to hygroscopic growth in a higher RH, the increase in PM2.1 resulted in a decrease in the visibility. The Interagency Monitoring of Protected Visual Environments (IMPROVE) method was used to estimate the light extinction coefficients (LEC) from the measured concentrations of chemical species. Organic matter (OM), ammonium nitrate (AN), and ammonium sulfate (AS) were the three dominant species that contributed to the LEC in Beijing and had the highest proportions of total contributions to the LEC in the summer, accounting for 32.2%, 25.9%, and 24.4%, respectively. The LEC of sea salts did not change much throughout the year and accounted for 4.1-5.3% in Beijing and 4.8-7.4% in Tianjin. According to the Ambient Air Quality Standard, the days were divided into pollutional days (PD) and attained days (AD). The increasing concentrations of AN, AS and OM resulted in an increase in the LEC in the NCP, which led to the occurrences of low visibility events during the autumn and winter. NH4+, NO3-, and SO42- mainly existed as fine size particles (diameter < 2.1 pm) in Beijing (73.5%, 80.7%, and 78.0% on PD and 63.3%, 79.4%, and 72.5% on AD, respectively) and Tianjin (81.0%, 80.6%, and 82.1% on PD and 71.5%, 44.3%, and 69.7% on AD, respectively). However, the CA originating mainly from fuel combustion also played an important part in the visibility impairment in the coarse size (2.1 < diameter < 9.0 pm). According to a positive matrix factorization (PMF) model, 37.1% and 26.5% of the LEC came from secondary aerosols on PD in Beijing and in Tianjin, respectively. In addition, biomass burning, fuel combustion and fugitive dust were also important contributing sources of the LEC in the NCP.

Transition-metal chalcogenides with an imaging element and tunable optical property are strongly desired as ideal high-efficiency photothermal theranostic agents to diagnose and eliminate tumors. Herein, we report on a one-pot solvothermal strategy to synthesize various porous cobalt sulfide hollow nanospheres (PCSH NSs) and elucidate the relation between PCSH NSs and their optical absorption as a guide to obtain optimal photothermal therapy (PTT) agents. After PEG modification, PEG-PCSH NSs show superexcellent photothermal conversion efficiency (∼70.1%) which is higher than that of binary transition-metal chalcogenides materials reported to date. A low dose (100 μL, 25 ppm) could completely ablate tumors under an 808 nm laser power of 0.7 W cm-2, reducing in vivo long-term residual agent content and thus lowering the possibility of side effects. Additionally, they also exhibit excellent biocompatibility, good photostability and utility for magnetic resonance imaging. Our results indicate that PCSH NSs can be considered as an outstanding PTT agent and give guidance towards the design of other photothermal theranostic agents.

Achieving cancer diagnosis and treatment simultaneously, multifunctional nanomaterials lead the trend in the development of nanomedicine. Manganese-based compounds have been well developed as excellent magnetic resonance (MR) imaging contrast agents, while they have not been demonstrated as photothermal agents (PTAs) due to their unsatisfactory near-infrared photoabsorption. Herein, we report a hydrophilic flower-like K2Mn4O8 superstructure self-assembled by ultrathin nanosheets that can work simultaneously as a PTA and an ultrasensitive T1-weighted magnetic resonance imaging (T1-MRI) enhancing agent. These K2Mn4O8 nanoflowers are efficient vehicles transforming 808 nm laser energy into thermal energy and then leading to the effective ablation of cancer cells in vitro and in vivo. Importantly, with a high longitudinal relaxivity (r1) of 4.6 mM−1 s−1, they also act as quite impressive T1-MRI enhancing agents. Both in vitro and in vivo experiments confirmed their great biocompatibility, low toxicity and high photothermal conversion capability. This is the first application of K2Mn4O8 as a PTA and would hopefully promote other Mn-based theranostics.

Cobalt oxide (Co3O4) has been extensively utilized as a promising oxygen evolution reaction (OER) cocatalyst for solar photoelectrochemical (PEC) water splitting. However, the relationship between its oxygen vacancies and PEC conversion efficiency has yet to be determined. Herein, we demonstrate a rapid and highly efficient strategy for rationally constructing oxygen vacancies on Co3O4 cocatalysts by Ar-plasma treatment, which could significantly enhance the PEC water oxidation reactivity of TiO2-based photoanodes. The photocurrent density could be achieved up to 2.5 mA cm−2 (1.23 VRHE) under AM 1.5G irradiation (100 mW cm−2), up to 2 times higher than that of the untreated Co3O4/TiO2 samples. More specifically, the oxygen vacancy formation on Co3O4 cocatalysts not only facilitates the hole trapping ability for promoting interfacial charge separation and migration, but also provides more active sites for water oxidation. The rapid and highly efficient activation of OER cocatalysts by producing oxygen vacancies may be potentially a universal strategy for improving the photo-conversion efficiency of PEC photoanodes now available.

Sodium-ion batteries (SIBs) show practical applications in large-scale energy storage systems. But, their power density is limited by the sluggish Na+ diffusion into the cathode and anode materials. Herein, we demonstrate a prototype of ultrahigh power SIB, consisted of the high-rate Na3 V2 (PO4 )3 (NVP) cathode, graphite-type mesocarbon microbeads (MCMB) anode, and Na+ -diglyme electrolyte. It is found that the overpotential of the NVP cathode obeys the Ohmic rule. Thus, the as-synthesized NVP@C@CNTs cathode with the high conductive CNTs networks displays high electronic conductivity, reducing the overpotential and charge transfer resistances and leading to the remarkable rate capability over 1000C. For the MCMB anode, the initial [Na-diglyme]+ co-intercalation step is pseudocapacitive dominated, and then the expended graphite's layers ensure the subsequent fast ions diffusion. The rapid (de)intercalation kinetics in between the cathode and anode are well-matched. Thus, the assembled MCMB|1 M NaPF6 in diglyme|NVP@C@CNTs full-cell SIB delivers the energy density of 88 Wh kg-1 at high power density of ∼10 kW kg-1 . Even at the ultrahigh power density of 23 kW kg-1 , an energy density of 58 Wh kg-1 is obtained. The encouraging results of the full cell will promote the development of high-power SIB for large-scale applications in the future. This article is protected by copyright. All rights reserved.

Land surface temperature (LST) is an essential parameter in land–atmosphere interaction. However, it is still poorly understood about the effects of seasonal LST on the interannual LST change and the dominant driving force for the variation in LST. In this study, trends of time-series LST were analyzed by using both linear and nonlinear methods. Two indices were developed to evaluate the effects of seasonal LST trends on interannual LST change. The main driving factor of LST was identified based on each pixel. Two turning points were founded in 2007 and 2011 during the study period of 2003–2019. A significant cooling trend of LST appeared from 2007 to 2011/2012 with the rates of −0.2237 K/year (daytime) and −0.1239 K/year (nighttime). LST increased in almost all seasons except the daytime in autumn. The warming effect in spring and winter contributed 69.43% to interannual warming of daytime LST, and accounted for 59.02% of interannual warming of nighttime LST. In most regions of China, air temperature and vegetation were the dominant factors influencing the change of LST. The current research improved our understanding of changes of LST and the results can serve for mitigating and adapting to climate change.

Controlling ammonia (NH3) emissions has been proposed as a strategy to mitigate haze pollution. To explore the role of NH3 in haze pollution in Sichuan Basin, where agricultural activities are intense, hourly in situ data of NH3, as well as nitric acid and secondary inorganic aerosols (SIAs) were gathered in Chengdu from April 2017 to March 2018. We found that NH3 had an annual mean concentration of 9.7 ± 3.5 (mean ± standard deviation) μg m−3, and exhibited seasonal variations (spring > summer > autumn and winter) due to changes in emission sources and meteorological conditions (particularly temperature). Chengdu's atmosphere is generally NH3-sufficient, especially in the warm seasons, implying that the formation of SIAs is more sensitive to the availability of nitric acid. However, an NH3 “sufficient-to-deficient” transition was found to occur during winter pollution periods, and the frequency of NH3 deficiency increased with the aggravation of pollution. Under NH3-deficient conditions, the nitrogen oxidation ratio increased linearly with the increase in free NH3, implying that NH3 contributes appreciably to the formation of nitrate and thus to high PM2.5 loadings. No relationships of NH3 with fossil fuel combustion–related pollutants were found. The NH3 emissions from farmland and livestock waste in the suburbs of Chengdu and regional transport from west of Chengdu probably contribute to the occurrence of high PM2.5 loading in winter and spring, respectively. These results suggest that to achieve effective mitigation of PM2.5 in Chengdu, local and regional emission control of NH3 and NOx synergistically would be effective.

Ultrathin layered semiconductors have attracted particular attention for various photocatalytic applications, while their surface-structure changes under reaction conditions have been rarely concerned. Herein, the dynamic evolutions of surface atomic and electronic structures on ultrathin BiOCl photocatalysts were firstly explored by combining synchronous-illumination X-ray photoelectron spectroscopy (SI-XPS) with X-ray diffraction (SI-XRD). The related results clearly reveal that the exposed {001} facets of ultrathin BiOCl are terminated with chlorine atoms instead of generally considered oxygen atoms. Under steady states, the outward migration of chlorine atoms on BiOCl (001) surfaces resulted in the formation of Bi, Cl, and O atoms with multiple-valence states and length decrease of Cl O and Bi O bond within the lattice phase. Under excitation states, the surface chlorine atoms return back to the lattice phase, leading to the elongation of Bi Cl and Bi O bonds and the valence-state normalization of Bi, Cl, and O atoms. Owing to these significant atomic- and electronic-structure changes, ultrathin BiOCl nanosheets exhibit the prominent activity enhancement (21.4 μmol g−1 h−1) for CO2 reduction to CO compare with bulk BiOCl (3.3 μmol g−1 h−1).

The simultaneous observation and analysis of atmospheric fine particles (PM2.5) on a regional scale is an important approach to develop control strategies for haze pollution. In this study, samples of filtered PM2.5 were collected simultaneously at three urban sites (Beijing, Tianjin, and Shijiazhuang) and at a regional background site (Xinglong) in the Beijing–Tianjin–Hebei (BTH) region from June 2014 to April 2015. The PM2.5 at the four sites was mainly comprised of organic matter, secondary inorganic ions, and mineral dust. Positive matrix factorization (PMF) demonstrated that, on an annual basis, secondary inorganic aerosol was the largest PM2.5 source in this region, accounting for 29.2–40.5 % of the PM2.5 mass at the urban sites; the second-largest PM2.5 source was motor vehicle exhaust, particularly in Beijing (24.9 %), whereas coal combustion was also a large source in Tianjin (12.4 %) and Shijiazhuang (15.5 %), with particular dominance in winter. Secondary inorganic aerosol plays a vital role in the haze process, with the exception of the spring haze in Shijiazhuang and Tianjin, for which the dust source was crucial. In addition to secondary transformations, local direct emissions (coal combustion and motor vehicle exhaust) significantly contribute to the winter haze at the urban sites. Moreover, with the aggravation of haze pollution, the OC ∕ EC mass ratio of PM2.5 decreased considerably and the nitrate-rich secondary aerosol increased during all four seasons in Beijing, both of which indicate that local motor vehicle emissions significantly contribute to the severe haze episodes in Beijing. To assess the impacts of regional transport on haze pollution, the PMF results were further processed with backward-trajectory cluster analysis, revealing that haze pollution usually occurred when air masses originating from polluted industrial regions in the south prevailed and is characterized by high PM2.5 loadings with considerable contributions from secondary aerosols. This study suggests that control strategies to mitigate haze pollution in the BTH region should focus on the reduction of gaseous precursor emissions from fossil fuel combustion (motor vehicle emissions in Beijing and coal combustion in Tianjin, Hebei, and nearby provinces).

For underwater vehicle navigation sensors, the output signal periods are different and time-varying. This would result in the decline of precision, and even wrong results. To deal with the problem, this paper puts forward a multi-sensor, adjustable-period integrated navigation method based on multi-stage signal trigger. This method considers the valid signals of a Doppler Velocity Log (DVL) as the trigger signals of a Dead-Reckoning (DR) navigation program. It also considers the valid signals of an acoustic positioning sensor as the trigger signals of the integrated navigation program. In this method, it can adjust the filtering period in real time. According to the time label of signals, this method actualises the time-space alignment of sensors. Then it conducts DR navigation and integrated navigation. The method can not only utilise the valid signals of each sensor sufficiently but also fuses the data based on time-space alignment efficiently. Sea trial data shows that when the output signal periods are certain, navigation precision of the method in this paper is better than a non-adjustable-period filtering method. Moreover, in poor conditions, it can also attain a high precision.

In this study, we report narrow-size distribution Zn 2 SnO 4 (ZSO) nanoparticles, which are produced by low-temperature solution-processed used as the electron extraction layer (EEL) in the inverted polymer solar cells (i-PSCs). Moreover, poly[(9,9-bis(3′-( N , N -dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) is used to modify the surface properties of ZSO thin film. By using the ZSO NPs/PFN as the EEL, the i-PSCs fabricated by poly[4,8-bis(2-ethylhexyloxyl)benzo[1,2-b:4,5-b′] dithio-phene-2,6-diyl-altethylhexyl-3-fluorothithieno [3,4-b]thiophene-2-carboxylate-4,6-diyl] (PTB7) blended with (6,6)-phenyl-C 71 -butyric acid methylester (PC 71 BM) bulk heterojunction (BHJ) composite, exhibits a power conversion efficiency (PCE) of 8.44%, which is nearly 10% enhancement as compared with that of 7.75% observed from the i-PSCs by PTB7:PC 71 BM BHJ composite using the ZnO/PFN EEL. The enhanced PCE is originated from improved interfacial contact between the EEL with BHJ active layer and good energy level alignment between BHJ active layer and the EEL. Our results indicate that we provide a simple way to boost efficiency of i-PSCs.

In this study, we report a simple way to fabricate VOx thin film from pure-water solution, as the hole extraction layer (HEL) for perovskite hybrid solar cells (pero-HSCs). Furthermore, an aminopropanoic acid (APPA) interfacial layer is used to modify VOx thin film for reducing the charge carrier recombination rate. As a result, the pero-HSCs with the VOx/APPA HEL exhibits better device performance than that of the pero-HSCs with the VOx HEL and the pero-HSCs with poly(3,4-ethylenedioxythiophene):poly-(styrenesulfonate) HEL. Moreover, the pero-HSCs with the VOx/APPA HEL exhibits hysteresis-free characteristics. All these results indicate that we report a simple approach to realize high performance of perovskite hybrid solar cells.

Chengdu, the capital of Sichuan Province and the main city in Sichuan basin, is one of the heavily polluted cities in China. The characteristics of single particles in the atmosphere over Chengdu are critical for the in-depth understanding of their sources, formation mechanisms, and effects. In this study, a continuous ambient aerosol measurement was performed in summer in Chengdu with a single particle aerosol mass spectrometer (SPAMS) and other monitoring instruments. The particulate matter (PM) mass concentrations were low during our study period: PM2.5 and PM10 (aerosol particles with an aerodynamic diameter of less than 2.5 or 10 μm) were 40.5 ± 23.6 μg m−3 and 67.0 ± 38.1 μg m−3, respectively. This was mainly caused by the favorable meteorological conditions during the summer season. Twelve particle types were identified and classified as dust particles (Dust), four types of carbonaceous particles, organic nitrogen and potassium containing particles (KCN), four types of secondary particles, Na-K-containing particles (NaK), and metal-containing particles (Metal). The highest contribution of particles was from potassium with elemental carbon (KEC; 23.0%), and the lowest from elemental carbon (EC; 0.2%). All types of particles showed different diurnal variations and size distributions, which were closely related to their sources and reactions in the atmosphere. The eastern and southern air masses corresponded with high PM2.5 mass concentrations. The contributions of KEC and K-sulfate (KSO4) particles to PM2.5 were clearly higher than those in air masses from the southeast. During polluted days, the contributions of KEC and KSO4 particles increased, while the contributions of organic carbon (OC), combined OC and EC particles (OCEC), and K-nitrate (KNO3) particles decreased. This shows the importance of biomass burning and industrial emissions for the PM2.5 pollution in Chengdu. These results will be useful for the in-depth understanding of the PM2.5 pollution in Chengdu, even in Sichuan basin.

CuCo2O4 maguey-like nanowires were obtained via a facile hydrothermal reaction and subsequent annealing at 300 °C for 3 h. The CuCo2O4 nanowires interacting with each other to form CuCo2O4 maguey-like nanowires structure offers the great specific surface area, excellent electron and ion transfer ability, easy approach for electrolyte transmitting to electrode surface. Our prepared CuCo2O4 electrode materials showed a high areal capacitance of 3.27 F cm−2 at 5 mA cm−2, an outstanding specific capacitance of 982 F g−1 at 1.5 A g−1 and an excellent capacitance retention of 100.94% after 3000 circles at 50 mV s−1. In addition, a symmetry supercapacitor was been assembled with a high energy density of 16.87 Wh kg−1, a high power density of 8.2 kW kg−1 and outstanding cycle life, which demonstrates that our prepared material has great potential application for supercapacitors.

A self-powered high-performance broadband photodetector was fabricated, based on n-Si(111)/p-NiO heterojunctions consisting of single-crystal NiO nanosheets, via a facile hydrothermal method. The device exhibited broadband detection capabilities (350–600 nm) and excellent self-powered performance, with an external quantum efficiency (EQE) as high as ∼20% under zero bias. Under a low reverse bias of −0.2 V, the highest photosensitivity (photo-dark current ratio) values of 938% and 2249% were achieved under illumination from 350 nm and 600 nm light (0.5 mW cm−2), respectively, which was several orders of magnitude higher than for previously reported Si/NiO heterojunction photodetectors. Under a high reverse bias of −2 V, the excellent EQE of the device was found to be between 62.5% and 89.5% upon illumination from 350–600 nm light. In addition, the fast response speed of the as-fabricated device was less than 30 ms. The results indicate that n-Si(111)/p-NiO heterojunction photodetectors made of single-crystal NiO nanosheets have obvious advantages for application in high-performance and energy-saving optoelectronic devices.

Janus heterostructural materials as photothermal agents with enhanced optical conversion capability are promising for artery inflammation treatment by the hyperthermia of macrophages, a primordial part in the artery inflammation response that can deteriorate into atherosclerosis and even break the vessels. Herein, a synthesis route of Janus Ag/Ag

Breast cancer is the most frequently diagnosed malignancy among women, and triple-negative breast cancer (TNBC) is a highly aggressive subtype. Increasing evidence has shown that lncRNAs are involved in tumor growth, cell-cycle, and apoptosis through interactions with miRNAs or mRNAs. However, there is still limited data on ceRNAs involved in the molecular mechanisms underlying TNBC. In this study, we applied the weighted gene co-expression network analysis to the existing microarray mRNA and lncRNA expression data obtained from the breast tissues of TNBC patients to find the hub genes and lncRNAs involved in TNBC. Functional enrichment was performed on the module that correlated with Ki-67 status the most (Turquoise module). The hub genes in the Turquoise module were found to be associated with DNA repair, cell proliferation, and the p53 signaling pathway. We performed co-expression analysis of the protein-coding and lncRNA hub genes in the Turquoise module. Analysis of the RNA-seq data obtained from The Cancer Genome Atlas database revealed that the protein-coding genes and lncRNAs that were co-expressed were also differentially expressed in the TNBC tissues compared with the normal mammary tissues. On the basis of establishing the ceRNA network, two mRNAs (RAD51AP1 and TYMS) were found to be correlated with overall survival in TNBC. These results suggest that TNBC-specific mRNA and lncRNAs may participate in a complex ceRNA network, which represents a potential therapeutic target for the treatment of TNBC.

Regenerative capacity is frequently impaired in aged organs. Stress to aged organs often causes scar formation (fibrosis) at the expense of regeneration. It remains to be defined how hematopoietic and vascular cells contribute to aging-induced regeneration to fibrotic transition. Here, we find that aging aberrantly reprograms the crosstalk between hematopoietic and vascular cells to impede the regenerative capacity and enhance fibrosis. In aged lung, liver, and kidney, induction of Neuropilin-1/hypoxia-inducible-factor 2α (HIF2α) suppresses anti-thrombotic and anti-inflammatory endothelial protein C receptor (EPCR) pathway, leading to formation of pro-fibrotic platelet-macrophage rosette. Activated platelets via supplying interleukin 1α synergize with endothelial-produced angiocrine chemokine to recruit fibrogenic TIMP1high macrophages. In mouse models, genetic targeting of endothelial Neuropilin-1-HIF2α, platelet interleukin 1α, or macrophage TIMP1 normalized the pro-fibrotic hematopoietic-vascular niche and restored the regenerative capacity of old organs. Targeting of aberrant endothelial node molecules might help propel "regeneration without scarring" in the repair of multiple organs.

Near-infrared (NIR) light has been widely applied in the field of photothermal therapy (PTT). Recent advances in the light wavelength for efficient cancer PTT have gradually shifted from the first NIR (NIR-I) biowindow (700-1000 nm) to the second NIR (NIR-II) biowindow (1000-1350 nm) owing to its intrinsic deeper tissue penetration ability and a higher maximum permissible exposure (MPE) value. Herein, we have prepared nickel sulphide (Ni9S8) nanoparticles (NPs) with a full-spectrum-absorption (400 nm-1100 nm) in the NIR region. By a fair comparison, it is found that the PTT using the NPs upon irradiation from an NIR-II (i.e., 1064 nm) laser is more efficient than that from an NIR-I (i.e., 808, 915, and 976 nm) laser. The large mass extinction coefficient value (22.18 L g-1 cm-1) and high photothermal conversion efficiency (46%) at 1064 nm make these NPs promising candidates for NIR-II photo-thermal therapy. This study will benefit future exploration and optimization of nickel-based photoabsorbers utilizing NIR-II light for photothermal applications.

A ratiometric fluorescent aptasensor based on energy transfer between [Ru(bpy)

Oxygen vacancy (Vo) on transition metal oxides plays a crucial role in determining their chemical/physical properties. Conversely, the capability to directly detect the changing process of oxygen vacancies (Vos) will be important to realize their full potentials in the related fields. Herein, with a novel synchronous illumination X-ray photoelectron spectroscopy (SI-XPS) technique, we found that the surface Vos (surf-Vos) exhibit a strong selectivity for binding with the water molecules, and sequentially capture an oxygen atom to achieve the anisotropic self-healing of surface lattice oxygen. After this self-healing process, the survived subsurface Vos (sub-Vos) promote the charge excitation from Ti to O atoms due to the enriched electron located on low-coordinated Ti sites. However, the excessive sub-Vos would block the charge separation and transfer to TiO

The Sichuan Basin has experienced serious air pollution from fine particulate matter (PM2.5) in the past few years with biomass burning has been identified as a major source of PM2.5 in this region. We used single particle aerosol mass spectrometer to investigate the characteristics of biomass burning particles in three interacting cities representing different types of urban environment in the Sichuan Basin. A total of 739,794, 279,610, and 380,636 biomass burning particles were detected at Ya'an, Guang'an, and Chengdu, which represented 42%, 69%, and 61%, respectively, of the total number of particles. We analyzed the chemical composition, transportation, and evolution of biomass burning particles. The contribution of K-elemental carbon and K-secondary inorganic particles was highest in Ya'an (36%) and Guang'an (47%), respectively, reflecting the important role of fresh biomass burning particles and long-distance transport in these two cities. Air masses originating from different directions corresponded to different levels of PM2.5 and the contributions of polluted clusters increased significantly on polluted days. Fresh and secondary inorganic biomass burning particles increased pollution at Ya'an and Guang'an, respectively, but dominated different stages of pollution in Chengdu. K-nitrate particles were formed by photochemical reactions, whereas K-sulfate particles were formed by both photochemical and liquid-phase reactions. Investigation of the degree of particle aging showed that there were more fresh particles at Ya'an and more aged particles at Guang'an. These results are useful in helping our understanding of the characteristics of biomass burning particles and evaluating their role in PM2.5 pollution in the Sichuan Basin.

Bacteria tightly regulate intracellular zinc levels to ensure sufficient zinc to support essential functions, while preventing toxicity. The bacterial response to zinc limitation includes the expression of putative zinc metallochaperones belonging to subfamily 1 of the COG0523 family of G3E GTPases. However, the client proteins and the metabolic processes served by these chaperones are unclear. Here, we demonstrate that theBacillus subtilisYciC zinc metallochaperone (here renamed ZagA forZTPactivatedGTPaseA) supportsde novofolate biosynthesis under conditions of zinc limitation through direct interaction with the zinc dependent GTP cyclohydrolase, FolE. Furthermore, we identify a role for the alarmone ZTP, a modified purine biosynthesis intermediate, in the response to zinc limitation. ZTP, a signal of 10-formyl-tetrahydrofolate deficiency (10f-THF) in bacteria, transiently accumulates as the Zn dependent GTP cyclohydrolase FolE begins to fail and stimulates the interaction between ZagA and FolE to sustain folate synthesis despite declining zinc availability.ImportanceMetallochaperones provide a mechanism for cells to regulate the delivery of metals to newly synthesized apoproteins. By selectively targeting specific proteins for metallation, cells can ensure that key pathways remain functional even as metals become limiting for growth. The COG0523 family of proteins contain a subgroup of candidate metallochaperones (the YciC subfamily) induced under conditions of zinc limitation. Although YciC family proteins have been suggested to be GTP-dependent metallochaperones, specific interactions with client proteins have not been demonstrated. Here, we show that theBacillus subtilisYciC (renamed ZagA) protein responds to ZTP as an activating ligand rather than GTP, and interacts specifically with a Zn-dependent enzyme critical for folate synthesis (FolE). Thus, under conditions of Zn limitation ZagA is synthesized, and as folate synthesis fails, it selectively delivers Zn to FolE to sustain folate synthesis.

Controlling the electrical conductance and in particular the occurrence of quantum interference in single-molecule junctions through gating effects has potential for the realization of high-performance functional molecular devices. In this work we used an electrochemically gated, mechanically controllable break junction technique to tune the electronic behaviour of thiophenebased molecular junctions that show destructive quantum interference features. By varying the voltage applied to the electrochemical gate at room temperature, we reached a conductance minimum that provides direct evidence of charge transport controlled by an anti-resonance arising from destructive quantum interference. Our molecular system enables conductance tuning close to two orders of magnitude within the non-faradaic potential region, which is significantly higher than that achieved with molecules not showing destructive quantum interference. Our experimental results, interpreted using quantum transport theory, demonstrate that electrochemical gating is a promising strategy for obtaining improved in situ control over the electrical performance of interference-based molecular devices. &nbsp