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How do habit and skill relate to one another? Among many traditions of habit research, we suggest that “slips-of-action” habits are the kind most likely to relate to motor skill. Habits are traditionally thought of as a property of behavior as a whole. We suggest, however, that habits are better understood at the level of underlying component computations and, at this level, habits can be considered equivalent to the phenomenon of automaticity in skill learning – improving speed of performance at the cost of flexibility. Lastly, we consider the importance of habits in learning complex tasks given limited cognitive resources and suggest that deliberate practice can be viewed as an iterative process of breaking and restructuring habits to improve performance.

Neuroinflammation plays a significant role in inducing depression-like behavior. Tetrahedral DNA nanostructures (TDNs) are molecules that exhibit anti-inflammatory properties and can effectively penetrate the blood-brain barrier. Thus, researchers have hypothesized that TDNs regulate the secretion of proinflammatory cytokines and consequently alleviate depression-like behavior. To test this hypothesis, we investigated the effect of TDNs on the depression-like behavior of C57 mice induced by lipopolysaccharide (LPS). We performed open-field, tail suspension, and sucrose preference tests on LPS- and LPS/TDN-treated mice. The results indicated that the injection of TDNs into LPS-treated mice resulted in increased velocity, center zone duration, frequency to the center zone, and sucrose preference, and decreased immobility time. Immunofluorescence results indicated that peripheral administration of LPS in the mice activated inflammation, which culminated in distinct depression-like behavior. However, TDNs effectively alleviated the inflammation and depression-like behavior through the reduction of the expression levels of proinflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α in the brain. Additionally, TDNs normalized the expression level of microglia cell activation markers, such as ionized calcium binding adaptor molecule 1, in the hippocampus of mice. These results indicated that TDNs attenuated the LPS-induced secretion of inflammatory factors and consequently alleviated depression-like behavior.

As one of the specific biomarkers of anthrax, timely, sensitive and accurate detection of 2,6-dipicolinic acid (DPA) plays an important role in preventing biological weapons attacks and disease outbreaks. Here, multiemission Eu3+/covalent- organic framework (COFDTA-TFP) and Tb3+/COFDTA-TFP were constructed by the coordination between Eu3+ or Tb3+ with fluorescent COFDTA-TFP which was prepared by amine-aldehyde dehydration condensation between 2,5-diaminoterephthalic acid and 2,4,6-triformylphloroglucinol for the first time. The Eu3+/COFDTA-TFP and Tb3+/COFDTA-TFP can emit non-overlapping fluorescence of COFDTA-TFP and Eu3+ or Tb3+, which was used to ratiometric detection of DPA. Due to the strong coordination between the nitrogen atoms in the pyridine ring and the oxygen atoms in the carboxyl group of DPA with Eu3+ or Tb3+, DPA replaced coordinated H2O to sensitize fluorescence of Eu3+ or Tb3+ by “antenna” effect but fluorescence of COFDTA-TFP with two-dimensional lamellar structure was kept constant as a reference. The linear range and detection limit of ratiometric fluorescence sensor based on Eu3+/COFDTA-TFP for detection of DPA are 0.01–12 µM and 4.2 nM, respectively. The linear range and detection limit of ratiometric fluorescence sensor based on Tb3+/COFDTA-TFP for detection of DPA are 0.01–9.0 µM and 2.9 nM, respectively.

Summary Rationally designing an appropriate support plays significant roles in catalysis through anchoring active sites firmly, enabling fast mass transport, and confining reaction fields. Recently, nitrogen-doped ordered mesoporous carbons (NOMCs) are emerging as an intriguing support due to well-defined ordered pore channels, unique confined microenvironment, and abundant N ligands, which create more possibilities of achieving catalytic orders and designing better catalysts. Here, we firstly cover the potentials of NOMCs in designing desirable catalysts with special emphasis on the characters of NOMCs toward catalysis. Then, various synthetic strategies for NOMCs are summarized, including (1) nanocasting, (2) solution collaborative self-assembly, (3) evaporation-induced self-assembly, and (4) solvent-free method. Next, we detail the catalytic applications of NOMCs-based metal-free, metal-nanoparticle, and single-atom catalysts across electrocatalysis and organic synthesis. Finally, we give a perspective for NOMCs about the current challenges and future opportunities confronted in their fundamental research and practical applications.

Receptor activator of NF-κB (RANK) expression is increased in podocytes of patients with diabetic nephropathy. However, the relevance of RANK to diabetic nephropathy pathobiology remains unclear. Here, to evaluate the role of podocyte RANK in the development of diabetic nephropathy, we generated a mouse model of podocyte-specific RANK depletion (RANK-/-Cre T), and a model of podocyte-specific RANK overexpression (RANK TG), and induced diabetes in these mice with streptozotocin. We found that podocyte RANK depletion alleviated albuminuria, mesangial matrix expansion, and basement membrane thickening, while RANK overexpression aggravated these indices in streptozotocin-treated mice. Moreover, streptozotocin-triggered oxidative stress was increased in RANK overexpression but decreased in the RANK depleted mice. Particularly, the expression of NADPH oxidase 4, and its obligate partner, P22phox, were enhanced in RANK overexpression, but reduced in RANK depleted mice. In parallel, the transcription factor p65 was increased in the podocyte nuclei of RANK overexpressing mice but decreased in the RANK depleted mice. The relevant findings were largely replicated with high glucose-treated podocytes in vitro. Mechanistically, p65 could bind to the promoter regions of NADPH oxidase 4 and P22phox, and increased their respective gene promoter activity in podocytes, dependent on the levels of RANK. Taken together, these findings suggested that high glucose induced RANK in podocytes and caused the increase of NADPH oxidase 4 and P22phox via p65, possibly together with the cytokines TNF- α, MAC-2 and IL-1 β, resulting in podocyte injury. Thus, we found that podocyte RANK was induced in the diabetic milieu and RANK mediated the development of diabetic nephropathy, likely by promoting glomerular oxidative stress and proinflammatory cytokine production.

Background Identifying data-driven subtypes of major depressive disorder (MDD) holds promise for parsing the heterogeneity of MDD in a neurobiologically informed way. However, limited studies have used brain structural covariance networks (SCNs) for subtyping MDD. Methods This study included 145 unmedicated patients with MDD and 206 demographically matched healthy control subjects, who underwent a structural magnetic resonance imaging scan and a comprehensive neurocognitive battery. Patterns of structural covariance were identified using source-based morphometry across both patients with MDD and healthy control subjects. K-means clustering algorithms were applied on dysregulated structural networks in MDD to identify potential MDD subtypes. Finally, clinical and neurocognitive measures were compared between identified subgroups to elucidate the profile of these MDD subtypes. Results Source-based morphometry across all individuals identified 28 whole-brain SCNs that encompassed the prefrontal, anterior cingulate, and orbitofrontal cortices; basal ganglia; and cerebellar, visual, and motor regions. Compared with healthy control subjects, individuals with MDD showed lower structural network integrity in three networks including default mode, ventromedial prefrontal cortical, and salience networks. Clustering analysis revealed two MDD subtypes based on the patterns of structural network abnormalities in these three networks. Further profiling revealed that patients in subtype 1 had younger age of onset and more symptom severity as well as greater deficits in cognitive performance than patients in subtype 2. Conclusions Overall, we identified two MDD subtypes based on SCNs that differed in their clinical and cognitive profile. Our results represent a proof-of-concept framework for leveraging these large-scale SCNs to parse heterogeneity in MDD.

With an aging population, late-life depression has been a major health problem in rural China. This study aims to explore the gender-specific prevalence of geriatric depression in rural Tianjin, its influencing factors, and to provide a scientific basis for the prevention and intervention of depression in the elderly.A cross-sectional study of 4,933 elderly individuals in rural Tianjin was conducted using the cluster sampling method. The independent samples t-test and chi-squared test were used to assess differences in participants' characteristics by depressive symptoms, while multiple linear regressions and multiple logistic regressions were used to analyze the potential influencing factors of depression.The prevalence of geriatric depression was found to be 12.2% in the study participants (9.5% in men and 14.5% in women). Gender, education, household income, employment, living alone, social activities, physical exercise and chronic diseases were associated with depression (P0.05). In addition to the above factors, sleep duration was also related with scores on self-rating depression scale (P0.05).The study used a cross-sectional approach, so causation cannot be concluded.Late-life depression is a serious mental health issue in rural China, highlighting the importance of appropriate diagnosis and treatment as a priority to improve the quality of mental health.

The prominent dispersibility of graphene oxide (GO) and superior mechanical properties of multi-walled carbon nanotubes (MWCNTs) make them potential materials for reinforcing cementitious composites. The aims of this study were to investigate the effectiveness and mechanisms of GO/MWCNT admixtures on the impermeability of cementitious composites. Comparative tests concerning the transport properties between plain cement pastes and GO/MWCNT-OPC pastes at different water-to-cement (W/C) ratios were conducted in this study. Mercury intrusion porosimetry (MIP) tests were carried out to characterize the pore structures of the cement pastes, and the fractal dimensions were utilized to exploit the relationship between the pore structures and permeability-related properties. Power’s model, general effective media (GEM) theory, and scanning electron microscopy (SEM) images were used to illustrate the mechanism of pore structure enhancement. The results imply that mixing GO/MWCNTs into cementitious composites enhances the impermeability of hardened pastes, and the reinforcing efficiency rate in impermeability decreases linearly with the increment of W/C ratio. The fractal dimensions based on the MIP data characterized the pore structures and predicted the transport properties with considerable accuracy. Furthermore, the role of GO/MWCNTs as nucleating sites for hydration reaction and net-like distribution in the composites may explain the impermeability enhancement mechanism induced by the additional GO/MWCNTs. However, GO/MWCNTs tend to re-agglomerate due to the longer setting times at high W/C ratios and lead to a nonuniform distribution of hydration products, which is responsible for the incompetent reinforcing effects.

Exosomal transfer of oncogenic miRNAs can enhance recipient cell growth, metastasis and chemoresistance. Currently we found that microRNA-501-5p (miR-501) was overexpressed in doxorubicin-resistant gastric cancer (GC) SGC7901/ADR cell-secreted exosomes (ADR Exo) than that in SGC7901 cell-secreted exosomes (7901 Exo). ADR Exo was internalized by SGC7901, and a Cy3-miR-501 mimic was transferred from SGC7901/ADR to SGC7901 via exosomes. ADR Exo conferred doxorubicin resistance, proliferation, migration and invasion abilities to negative control miRNA inhibitor-expressing GC cells, whereas it inhibited apoptosis. MiR-501 knockdown or BH3-like motif-containing protein, cell death inducer (BLID) overexpression could reverse the effects of ADR Exo on recipient cells. SGC7901 cells cocultured with SGC7901/ADR prior to treatment with GW4869 or transfection of a miR-501 inhibitor were sensitive to doxorubicin and exhibited attenuated proliferation, migration and invasion and increased apoptosis. The intratumoral injection of ADR Exo into negative control miRNA inhibitor-expressing SGC7901 cells induced rapid subcutaneous tumor growth and resistance to doxorubicin compared to that of miR-501 knockdown or BLID-overexpressing cells. This effect is possibly achieved by exosomal miR-501-induced downregulation of BLID, subsequent inactivation of caspase-9/-3 and phosphorylation of Akt. Exosomal miR-501 might be a therapeutic target for GC.

A microbial fuel cell (MFC) is a bio-electrochemical device that convert the chemical energy to electrical energy by the oxidation of microorganisms at bioanode, while its powder generation is largely depending on the activity and durability of cathode catalysts. In this work, we report the design and synthesis of N-doped carbon nanotubes/reduced graphene oxide (rGO) nanosheet hybrids with mixed-dimensional characteristics as high-performance oxygen reduction reaction catalyst for cost-saving MFCs. Co-glycolate nanoparticles uniformly coated on rGO nanosheets are reduced to Co nanoparticles, acting as catalysts for the catalyst mediated growth of carbon nanotubes with abundant metal-nitrogen-carbon active sites. The half-wave potential of hybrid electrocatalyst are 0.859 V (vs RHE), comparable to that of benchmark Pt/C. A maximum power density of 1329 mW cm−2, 1.37 times higher than that of commercial Pt/C catalyst, is achieved in single-chamber MFCs using optimized hybrid electrocatalysts.

A novel ratiometric fluorescent sensor for superoxide radical (O2•−) detection was developed based on Schiff base polymer (SBP)/rhodamine-B (SBP/RDB) nanocomposites. The SBP/RDB was investigated by atomic force microscopy, scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, N2 adsorption/desorption isotherms and fluorescence spectroscopy, etc. The results showed the SBP was two-dimensional (2D) crystalline nanosheet with the thickness of 0.5 nm. RDB could be self-assembled on each of 2D SBP surface to form SBP/RDB due to the hydrogen bond between N atoms of SBP and –COOH of RDB as well as π-π interaction. The SBP/RDB exhibited the characteristic fluorescence emission of both SBP at 485 nm and RDB at 585 nm under an excitation of 270 nm. The 2D SBP was not only acted as template to assemble RDB, but also used as reference fluorescence for O2•− detection. The SBP/RDB fluorescence probe for O2•− detection demonstrated high sensitivity and selectivity with good linear range (11.1 ± 0.76 nM–8.0 ± 0.36 μM) and low detection limit (3.7 ± 0.42 nM). Because of the low cost and simple operation, the work sheds some new light to construct ratiometric fluorescent sensors based on SBP to detect O2•− in drinking water and human blood serum for commercial applications.

A simple and sensitive electrochemical method was developed for ampicillin detection based on the protective effect of aptamer-antibiotic conjugate towards endonuclease DpnII activity. Without ampicillin, DNA aptamer firstly hybridizes with the capture probe to form double strand DNA (dsDNA) structure. Then, dsDNA is cleaved by DpnII restriction endonuclease to form two dsDNA fragments. In which, one fragment is released from electrode surface and the other fragment is kept on electrode surface. Then, the dsDNA fragment kept on electrode surface is further digested by Exo III, which leads to the release of the dsDNA fragment from electrode surface. Thus, the electrochemical signal increases due to the decrease of the interface electron transfer resistance causing by the release of dsDNA from electrode surface. However, the formation of dsDNA is blocked when forming aptamer-ampicillin conjugate, which makes the obstruction of the digestion of DpnII and Exo III towards capture probe. Thus, a weak electrochemical signal is achieved due to the increase of the interface electron transfer resistance causing by the dsDNA on the electrode surface. Based on the relationship between ampicillin concentration and the decrease of the electrochemical signal, antibiotic is detected with low detection limit of 32 pM under optimal conditions, which is lower than the mandated maximum residue limit of European Union (9.93 nM). The developed method also presents good detection selectivity. Moreover, the applicability is confirmed by detecting antibiotic in milk and water samples with satisfactory results.

Based on the density functional theory calculations, the BP-(B3N3)n and Li@BP-(B3N3)n (BP = biphenylene, n = 1–4) systems, were designed for the first time and explored the effects of Li doping and B3N3 substitution on their nonlinear optical (NLO) properties. We find that, when the carbon rings are replaced by B3N3 units in the biphenylene, systems of enhanced static hyperpolarizabilities (β0) are delivered. And the position and the number of B3N3 unit have an important effect on the β0 value. Moreover, when one Li atom is adsorbed on the surface of B3N3-substituted BP, the β0 values of these systems are further dramatically enhanced to 2.24 × 104–1.42 × 106 au. The further investigations show that small transition energy is the decisive factor for their large β0 values. Specially, these Li-doped compounds exhibits high stability and excellent infrared (IR) transparency. These findings might provide valuable insights into the design of novel high-performance NLO materials based on BP flake.

A systematic analysis of electronic and nonlinear optical properties of a novel class of (super)alkali-doped complexes M/M3O@g-C3N4 (M Li, Na, K) is presented. These compounds exhibit considerable stability with large interaction energies, and M3O@g-C3N4 has higher stability than the corresponding M@g-C3N4. It is found that doping the (super)alkali can significantly narrow the wide energy gap of the pure g-C3N4 in the range of 2.04–2.84 eV, and these doped g-C3N4 show enhanced visible-light absorption. Due to the large charge transfer from (super)alkali to g-C3N4 moiety, these doped compounds exhibited significantly large first hyperpolarizabilities up to 2165–63761 au. The ratio between the vibrational and electronic contribution on hyperpolarizability indicates that the vibrational contributions play an important role in determining the static hyperpolarizabilities of certain systems. Therefore, (super)alkali-doped g-C3N4 are expected to be potential candidates for visible-light catalysis and high-performance nonlinear optical materials. We expect this work could provide a new idea for designing functional materials using superalkali clusters.

Here, a series of low-cost CoxNiyP nanoparticles embedded in N-doped porous carbon stood up on Ni foam nanocomposites (CoxNiyP@NC/NF) were prepared as efficient catalysts for hydrogen evolution reaction (HER) by a low temperature hydrothermal and phosphating method. Characterization of various techniques indicated the CoxNiyP nanoparticles with about 5 nm in diameter were uniformly embedded in NC to form CoxNiyP@NC nanosheets with thickness of 20–400 nm. The NC was composed of graphene and the CoxNiyP@NC nanosheets stood up on NF in crisscross fashion. The electrochemical results showed that the CoxNiyP@NC/NF nanocomposites showed high catalytic activity for HER in alkaline solution and its catalytic activity depended on the ratio of Co:Ni. At the ratio of Co:Ni of 4:1, the Co4NiP@NC/NF presented best HER performances with the overpotential of 70 mV at 10 mA cm−1, better than commercialized Pt. The Co4NiP@NC/NF also displayed a wonderful Faraday efficiency of 95%, suggesting that it could effectively convert electrical energy into chemical energy in HER. The catalytic activity of Co4NiP@NC/NF remained unchanged in 35 h, indicating the Co4NiP@NC/NF possessed good stability. The excellent HER performances might make it be a substitute for precious metal catalysts for hydrogen production.

Strain sensors are widely applied in the industry requiring specific signal amplifiers and signal readers. However, the devices are unable to read data quickly and intuitively. The present study introduces a highly accurate, repeatable, mold-free strain sensor comprising of an amplification mechanism and a smart-phone microscope. Generation of the amplification mechanism using rapid prototyping especially 3D printing is summarized and evaluated. The sensitivity of the proposed amplifier is (39.47 ± 1.34) for nylon and (37.74 ± 2.41) for ABS. A visual polydimethylsiloxane (PDMS) lens with a focal length of 7.23 mm is attached to the iphone6 camera, performing as a microscope for image acquisition, which provides an equivalent focal length of 6.7 mm and a resolution of 0.691 µm.

Transition metal sulfides are promising non-noble metal catalysts for water oxidation, a vital half reaction of electrocatalytic water splitting. However, the realization of tunable electronic structure and synergetic catalysis of cobalt sulfides is still a challenge. In this work, a salt-templating route was adopted to embed uniform Co9S8 nanoparticles into high-conductive N, S co-doped carbon nanosheets (Co9S8/N,S-CNs). Benefiting from the abundant catalytic active sites and optimized electronic structure, the as-prepared Co9S8/N,S-CNs exhibited high efficiency with a low overpotential of 325 mV to afford current density of 10 mA cm−2 and low Tafel slope of 86.3 mV dec−1 towards oxygen evolution in 1 M KOH alkaline electrolyte.

It is of great significance for superoxide anion (O2•−) detection due to its important role in regulation of biological function. The nanoscale coordination polymers (NCPs) core-shell nanostructures have attracted increasing interests for their nanosized-dependent properties. In this study, SiO2@Tb/guanosine 5′-monophosphate (GMP) NCPs with core-shell nanostructures was designed for O2•− detection. The SiO2@Tb/GMP NCPs core-shell nanostructures were produced by using SiO2 nanoparticles (NPs) as template to control their nano-size. First, Tb3+ was adsorbed on the surface of SiO2NPs by coordination with -COOH of SiO2NPs. Then the Tb/GMP NCPs shells were grown along the surface of SiO2NPs. The SiO2@Tb/GMP NCPs core-shell nanostructures were characterized with scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Zeta potential. The resulted SiO2@Tb/GMP NCPs core-shell nanostructures displayed strong Tb/GMP emission which decreased linearly with the increased O2•− concentration in the range from 5.3 nM to 6.0 μM with a limit detection of 2.18 nM. And the SiO2@Tb/GMP NCPs core-shell nanostructures also exhibited good selectivity and high sensitivity in HEPES buffer at pH 7.4.

Rational design of high-performance electrocatalysts with low cost and large abundance is highly desirable for water splitting technology. Here we report the synthesis of Ni3S2 pyramids coated with crimped graphene (Ni3S2@G), the unique configuration of which endows Ni3S2@G with large roughness, creating much more active sites along the edges. Moreover, the coupling of graphene enhances the electrical conductivity of the nanocomposite, and thus improves the electrocatalytic activity due to synergistic effect between graphene and Ni3S2. Ni3S2@G hybrid shows outstanding performance toward both hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) with low overpotentials (η10 = 103 mV for HER and η20 = 294 mV for OER) and small Tafel slope. Ni3S2@G electrode also exhibits superior full water splitting ability with a low cell voltage of 1.66 V.