Exploring Urban Green Space Optimization of the Urban Walking Life Circle in Fuzhou, China.

The spatial distribution of urban green spaces (UGS) is closely related to the health of residents and the ecological pattern of cities. Exploring the equity of UGSs plays an important role in urban planning and also provides guidance for urban development. Taking the main urban area of Fuzhou City as an example, this study uses network big data and census data to pinpoint the population demand, evaluates the accessibility and equity of UGS within the basic living circle, neighborhood living circle and daily living circle of residents at the scale of residential and sub-districts. Based on the G2SFCA model, we also quantify the actual effective UGS's service capacity. Then, using the scale and travel range as the entry point, we further discuss the similarities and differences under different scales and different travel ranges. Finally, optimization strategies are proposed for the construction status. The results show that: (1) The spatial allocation of urban green space resources varies significantly, and there is a serious inequity in the spatial distribution of urban green space under pedestrian conditions; (2) The results of UGS accessibility, equity, and service capacity in Fuzhou at both residential and sub-district scales are consistent; (3) Urban construction should be multi-level overall planning, combined with local economic and social development factors in accordance with local conditions to take measures. The results of the study can provide a scientific reference for the optimization of the spatial distribution of UGS.

Identification of driver genes and target drugs-related genes in liver cancer based on targeted next generation sequencing.

The purpose of this study was to identify gene mutations, high frequency mutations, and driver genes in liver cancer, and the marketed approved drugs of these genes, to provide evidence for targeted treatment of liver cancer since it is one of the most common cancers worldwide. 34 patients with liver cancer were included, and their blood samples were collected. The pathway enrichment analysis of the mutation gene was carried out through the KEGG database, and the genes with marketed approved drugs were screened according to the Pharmalaxy database. A total of 6,612 mutations in 1,241 genes were identified in 34 patients, in which 22 genes mutated in at least 40% of the samples and were thought to be high frequency mutation genes. All the mutations were analyzed using the MutSigCV software, and 30 genes with q<0.1 and p<0.05 were selected out as driver genes. Among them, LRP1B, MYC, NF1, and KEAP1 were coincident with high frequency mutation genes, which were considered key driver genes. Afterward, 181 genes with p<0.05 in MutSigCV software were analyzed for pathway enrichment. These genes were mainly enriched in four pathways, including MAPK mTOR, p53/cell cycle, and JAK-STAT pathways. Finally, there were 15 genes in four pathways that had marketed approved target drugs. To conclude, LRP1B, MYC, NF1, and KEAP1 were the candidate key driver genes for liver cancer, which might provide new insights for targeted therapy of liver cancer.

Analysis of adversity quotient of nursing students in Macao: A cross-section and correlation study.

OBJECTIVES: To investigate the adversity quotient (AQ) of Macao undergraduate nursing students and analyse its influencing factors. METHODS: A cross-section design was used, and a convenience sample of nursing students (n = 158 valid) was selected from a tertiary institute in Macao. In addition to demographic questions, the Chinese versions of the Adversity Quotient Scale, the Emotional Intelligence (EI) Scale, the Simplified Coping Style Questionnaire and the Parenting Styles Scale were used to assess the students' characteristics. RESULTS: The average AQ score of the students was 116.72 ± 11.39. AQ scores were negatively correlated with coping-negative, and maternal style (excessive interference, excessive protection) (r = -0.332, P < 0.001; r = -0.167, P = 0.036). Coping-negative entered the regression equation (F = 19.154, P < 0.001). The female nursing students had higher scores in ownership dimension of AQ than their male counterparts (31.98 ± 3.26 vs. 29.21 ± 3.08, t = -4.442, P < 0.001). CONCLUSIONS: The average AQ scores of Macao undergraduate nursing students were moderate. The female nursing students are more likely to attribute the cause of adversity to themselves, and specific psychosocial and cultural issues may be at play. There is a necessity for Macao nursing students to improve their ability to overcome setbacks. Special attention should be paid to the cultivation of students' positive coping styles.

In-situ catalytic pyrolysis upgradation of microalgae into hydrocarbon rich bio-oil: Effects of nitrogen and carbon dioxide environment.

Pyrolysis of Spirulina Platensis (SP) microalgae was carried out under different reaction environment such as nitrogen (N2) and carbon dioxide (CO2) at different reaction temperatures of 300, 350, 400, 450 and 500 °C. Catalytic upgradations were examined over solid acid (ZSM-5) and solid base (MgO) catalyst, and with ZSM-5-MgO catalysts mixtures. Results showed, pyrolysis of non-catalytic biomass yielded maximum bio-oil of 43.6% under N2. However catalytic upgradation in CO2 environment produced lower bio-oil due to the coke formation. Maximum bio-oil (46.2 wt%) was obtained with basic metal MgO catalyst in N2 environment compared to other catalyst and environments. Mixture of MgO-ZSM-5 catalyst improved the bio-oil yield (37.8-48.6 wt%) compared to individual catalytic reaction under N2 and CO2. Higher high heating value (HHV) was observed in catalytic bio-oil 36.8 MJ/Kg. Bio-oil (catalytic) analysis revealed that 64-70% of compounds are in hydrocarbon range. Bio-oil was rich in hydrocarbons of C7-C18 range with less oxygenated compounds.

Stable and Reusable Light-Responsive Reduced Covalent Organic Framework (COF-300-AR) as a Oxidase-Mimicking Catalyst for GSH Detection in Cell Lysate.

Covalent organic frameworks (COFs), as one of the most significant members of the porous organic frameworks, have been well used in the photocatalysis owing to their outspread π-conjugated framework, high crystallinity and regular pore structure. Herein, after reducing the labile imine-linked COF-300 to the more stable amine-linked COF-300-AR, we for the first time demonstrated that COF-300-AR was the light-responsive oxidase mimic. COF-300-AR exhibited excellent oxidase-mimicking activity under purple light stimulation (λ = 400 nm), which can catalyze the oxidation of classical substrates such as 3,3',5,5'-tetramethylbenzydine (TMB) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) by the formation of •OH and O2•- free radicals in the presence of dissolved oxygen. The COF-300-AR oxidase mimic has outstanding advantages of easy light control, high stability, good reusability, and highly catalytic oxidation capacity and has been applied to detect glutathione (GSH) levels in HL60 cells with good selectivity and high sensitivity. This study will broaden the sensing applications of COFs and offer a promising build block for the construction of artificial enzymes.

In situ fabrication of 3D COF-300 in a capillary for separation of aromatic compounds by open-tubular capillary electrochromatography.

Two-dimensional (2D) COFs have been successfully applied for various applications, such as capillary electrochromatography (CEC). Compared with 2D COFs, three-dimensional (3D) COFs have higher surface area and lower density, which should have superior potential as the separation medium in CEC. However, the 3D COFs on the inner wall of capillary is hard to fabricate in situ. Up to date, the application of 3D COFs in open-tubular capillary electrochromatography (OT-CEC) is still considered a challenge. For the first time the COF-300-coated capillary was prepared by in situ growth (COF-300 was made from terephthalaldehyde and tetra-(4-anilyl)-methane) on OT-CEC. Benzene, methylbenzene, styrene, ethylbenzene, naphthalene, 1-methylnaphthalene, and propylbenzene were used to evaluate the performance of the COF-300-coated capillary by OT-CEC. For three consecutive runs, the intraday relative standard deviations (RSDs) of migration time and peak areas were 0.1-0.4% and 2.5-8.3%, respectively. The interday RSDs of migration time and peak areas were 0.2-0.5% and 1.0-10.8%, respectively. Five groups of aromatic co mpounds were used to further study the separation mechanism, which indicated that hydrophobic interaction and size selection interaction are the main factors. It should be noted that the COF-300-coated capillary can be used for more than 140 runs with no observable changes of the separation efficiency. Graphical abstract The 3D COF-300-coated capillary was prepared by in situ growth for OT-CEC. Six groups of aromatic compounds were separated by 3D COF-300-coated capillary. Size selection and hydrophobic interaction affect the migration time of analytes.

A peptide-WS2 nanosheet based biosensing platform for determination of ß-secretase and screening of its inhibitors.

ß-Secretase (BACE1) is an important drug target in the treatment of Alzheimer's disease (AD). Therefore, sensitive detection of BACE1 is essential for AD treatment and drug discovery. In this work, a facile and sensitive fluorescence biosensing platform was developed for BACE1 detection. This sensing platform was constituted based on the interaction between a WS2 nanosheet and a peptide sequence. In the absence of BACE1, a FAM-labeled peptide substrate could be adsorbed on the surface of the WS2 nanosheet, thereby quenching its fluorescence. However, in the presence of BACE1, the hydrolysis of the peptide substrate by BACE1 triggers could occur with the subsequent release of short FAM-linked peptide fragments which could not be adsorbed on the surface of the WS2 nanosheet. This resulted in weak fluorescence quenching, thus restoring the fluorescence signal. By measuring the change in the fluorescence of the FAM-labeled peptide substrate, the fluorescence sensing platform based on the WS2 nanosheet could monitor BACE1. The proposed WS2 nanosheet-based platform exhibited excellent specificity and high sensitivity with a detection limit of 66 pM for BACE1. Importantly, we also demonstrated that this platform was suitable for the screening of BACE1 inhibitors. The proposed sensing platform not only provides a novel strategy for the BACE1 assay but also offers a potential tool for screening drugs.

User-Friendly Genetic Conditional Knockout Strategies by CRISPR/Cas9.

Loss-of-function studies are critically important in gene functional analysis of model organisms and cells. However, conditional gene inactivation in diploid cells is difficult to achieve, as it involves laborious vector construction, multifold electroporation, and complicated genotyping. Here, a strategy is presented for generating biallelic conditional gene and DNA regulatory region knockouts in mouse embryonic stem cells by codelivery of CRISPR-Cas9 and short-homology-arm targeting vectors sequentially or simultaneously. Collectively, a simple and rapid method was presented to knock out any DNA element conditionally. This approach will facilitate the functional studies of essential genes and regulatory regions during development.

High-performance electrochemical biosensor for nonenzymatic H2O2 sensing based on Au@C-Co3O4 heterostructures.

An ingenious and viable method for preparing heterogeneous Co3O4 dodecahedrons that contain carbon and encapsulated Au nanoparticles (Au@C-Co3O4) was proposed via pyrolysis of Au nanoparticle-encapsulated zeolitic imidazolate framework-67 (Au@ZIF-67). The obtained Au@C-Co3O4 possessed hierarchically porous structure, abundant active sites, excellent conductivity, and durability, all of which can significantly improve the analysis performance of the biosensor. Meanwhile, the fabricated electrode based on the porous Au@C-Co3O4 showed remarkable electrocatalytic performance towards H2O2 with a limit of detection of 19 nM and ultra-high sensitivity of 7553 µA mM-1 cm-2, even when the Au content in the composite was as low as 0.85 wt%. This novel biosensor was successfully used to monitor H2O2 concentration released from living cells, and the results can be used to identify cancer cells, thus advancing the use of transition metal oxides in the field of biosensing.

A novel biosensor based on boronic acid functionalized metal-organic frameworks for the determination of hydrogen peroxide released from living cells.

In this work, we report a durable and sensitive H2O2 biosensor based on boronic acid functionalized metal-organic frameworks (denoted as MIL-100(Cr)-B) as an efficient immobilization matrix of horseradish peroxidase (HRP). MIL-100(Cr)-B features a hierarchical porous structure, extremely high surface area, and sufficient recognition sites, which can significantly increase HRP loading and prevent them from leakage and deactivation. The H2O2 biosensor can be easily achieved without any complex processing. Meanwhile, the immobilized HRP exhibited enhanced stability and remarkable catalytic activity towards H2O2 reduction. Under optimal conditions, the biosensor showed a fast response time (less than 4s) to H2O2 in a wide linear range of 0.5-3000µM with a low detection limit of 0.1µM, as well as good anti-interference ability and long-term storage stability. These excellent performances substantially enable the proposed biosensor to be used for the real-time detection of H2O2 released from living cells with satisfactory results, thus showing the potential application in the study of H2O2-involved dynamic pathological and physiological process.

Recombinant expression, purification and antimicrobial activity of a novel antimicrobial peptide PaDef in Pichia pastoris.

The antimicrobial peptide PaDef was isolated from Mexican avocado fruit and was reported to inhibit the growth of Escherichia coli and Staphylococcus aureus in 2013. In this study, an N-terminal 6 × His tagged recombinant PaDef (rPaDef) with a molecular weight of 7.5 KDa, for the first time, was expressed as a secreted peptide in Pichia pastoris. The optimal culture condition for rPaDef expression was determined to be incubation with 1.5% methanol for 72 h at 28 °C under pH 6.0. Under this condition, the amount of the rPaDef accumulation reached as high as 79.6 µg per 1 ml of culture medium. Once the rPaDef peptide was purified to reach a 95.7% purity using one-step nickel affinity chromatography, its strong and concentration-dependent antimicrobial activity was detected to be against a broad-spectrum of bacteria of both Gram-negative and Gram-positive. The growth of these bacterial pathogens was almost completely inhibited when the rPaDef peptide was at a concentration of as low as 90 µg/ml. In summary, our data showed that rPaDef derived from Mexican avocado fruit can be expressed and secreted efficiently when P. pastoris was used as a cell factory. This is the first report on heterologous expression of PaDef in P. pastoris and the approach described holds great promise for antibacterial drug development.

Expression, purification and initial characterization of a novel recombinant antimicrobial peptide Mytichitin-A in Pichia pastoris.

Mytichitin-A is an antimicrobial peptide isolated from the serum of Mytilus coruscus and is reported to inhibit bacterial growth as tested on several Gram-positive bacteria. To produce large quantity of Mytichitin-A to further investigate its biological activity, nucleotide sequence encoding a recombinant 6 × His-Mytichitin-A (rMytichitin-A) peptide was synthesized and inserted into the inducible yeast expression vector pPICZαA. With the availability of such an expression vector called pPICZαA-Mytichitin-A, we transformed Pichia pastoris GS115 cells with a SacI-linearized pPICZαA-Mytichitin-A by electroporation. Transgenic strains secreting rMytichitin-A with a molecular weight of approximate 10 KDa as expected were obtained. The optimal culture condition for rMytichitin-A expression was determined to be 1.0% methanol induction, 96 h incubation at 28 °C and the amount of rMytichitin-A reached 45.5 µg/ml. The percentage of rMytichitin-A was estimated to be 73.6% of the total protein. After rMytichitin-A was purified using nickel ions affinity chromatography, approximate 9.1 mg pure rMytichitin-A was obtained from 500 ml of cell culture medium with 97.8% purity. More importantly, both the culture supernatant and purified rMytichitin-A inhibited the growth of Gram-positive bacteria, especially Staphylococcus aureus and Bacillus subtilis with a minimum inhibition concentration of as low as 31 and 48 µg/ml, respectively. Differently from the native protein, however, the rMytichitin-A is not active against Gram-negative bacteria. Taken together, this is the first report on the heterologous expression of Mytichitin-A in P. pastoris. Our study showed that P. pastoris is an effective expression system for producing large quantities of biologically active Mytichitin-A for both research and application purposes.

Synthesis of porous starch xerogels modified with mercaptosuccinic acid to remove hazardous gardenia yellow.

Mercaptosuccinic acid (MSA) molecules were inserted into potato starch, leading to the breaking of intrinsic H-bonds within macromolecular chains of starch and the formation of intermolecular H-bonds between MSA and starch, which could be verified by Fourier transform infrared spectroscopy (FT-TR). MSA modified porous starch xerogels (PSX/MSA) were obtained after freeze-drying the MSA modified starch, and they were characterized by field emission scanning electron microscopy (FESEM), exhibiting the intriguing porous structure due to the separation of starch chains by MSA molecules. The PSX/MSA were then used as the adsorbents to remove gardenia yellow (GY), a natural colorant with genotoxicity. Due to the porous structure of PSX and the introduced carboxyl groups from MSA, the adsorption capacity of the PSX/MSA was much higher than that of the starch xerogels alone (SX). The adsorption behaviors of GY by the PSX/MSA fitted both the Freundlich isotherm model and the pseudo-second-order kinetic model, and the efficient adsorption of GY suggested that the PSX/MSA might be potential adsorbents for the removal of dyes from contaminated aquatic systems.

Psychometric properties of a mainland Chinese version of the Iowa Infant Feeding Attitude Scale among postpartum women in China.

BACKGROUND: The Iowa Infant Feeding Attitude Scale (IIFAS) is used to evaluate maternal infant feeding attitude. The breastfeeding rate has declined but no validated instruments to assess infant feeding attitudes or related studies have been available in mainland China. AIMS: The purpose of this study was to assess the reliability and validity of a mainland Chinese version of the IIFAS among postpartum women. METHODS: Postpartum women (N = 660) were recruited from three university hospitals in Guangzhou in mainland China. The participants completed an IIFAS questionnaire before being discharged and accepted telephone follow-up sessions at 6 weeks and 3 months postpartum. The reliability of the scale was evaluated using intra-class correlations (ICC) for test-retest reliability, correlated item-total correlations and Cronbach's a. The validity of the scale was evaluated using the content validity index (CVI), construct validity using exploratory factor analysis and predictive validity using independent t-tests. RESULTS: The ICC was 0.861. The correlated item-total correlations ranged from 0.262-0.691. Cronbach's a was 0.623. The CVI was 0.996. Four factors were extracted using exploratory factor analysis and they contributed to 48.69% of the total variance. CONCLUSIONS: The mainland Chinese version of the IIFAS scale can be considered a reliable, valid and predictive scale for assessing infant feeding attitudes among women in mainland China. In-hospital scores on the scale were significant predictors of the infant feeding method and breastfeeding duration at 3 days, 6 weeks and 3 months postpartum. Construct validity was confirmed and showed four factors. However, future studies are required to improve the lower level internal consistency of the IIFAS.

Kinetic determination of tryptophan by using the B-Z oscillating chemical system.

A simple and rapid method was devised for determination of tryptophan, based on the Belousov-Zhabotinskii (B-Z) oscillating chemical system. Changes in oscillating period and amplitude were linearly proportional to the negative logarithm of L-tryptophan concentration over the range of 6.44 x 10(-7)-2.55 x 10(-4) M, with the regression coefficients of near unity and a lower detection limit of 6.5 x 10(-8) M. D-tryptophan was also examined although it is rarely found in most biological fluids, and perhaps not at all in natural proteins. The change of period against to negative logarithm of D-tryptophan concentration over the range of 4.9 x 10(-5)-8.24 x 10(-4) M is linear. Because the optimum conditions for determination of L- and D-tryptophan are not the same, a little amount of D-tryptophan does not affect the determination of L-tryptophan. Various influences were studied and a possible mechanism of perturbation to the B-Z oscillator by tryptophan was also discussed. Spectrophotometry and fluorescence spectrophotofluorimetry were used for comparison and confirmation of the results.

Determination of 1-naphthylamine by using oscillating chemical reaction.

A simple and rapid analytical method for determining 1-naphthylamine was proposed by perturbation with different amounts of 1-naphthylamine on the classical Belousov-Zhabotinskii (B-Z) oscillating chemical system. The results show that the changes both in oscillating period and amplitude were linearly proportional to the logarithm of the concentration of 1-naphthylamine (logC) very well ranging from 7.08x10(-5) to 7.08x10(-6) molL(-1) and 7.08x10(-5) to 1.0x10(-6) molL(-1), with the corresponding regression coefficient are 0.9957 and 0.9922, respectively. For the later, a lower detection limit of 5.64x10(-9) molL(-1) was obtained. Influence of injection point, temperature and reactant variables on this oscillating system was also investigated in detailed. The results obtained were compared with other determination methods. A possible reaction mechanism was interpreted by using bromide ion selective electrode to inspect the concentration change of Br(-) ion in the oscillating process.

Michael addition of pyrimidine with disaccharide acrylates catalyzed in organic medium with lipase M from Mucor javanicus.

The Michael addition of fluorouracil (0.01 mol), uracil (0.01 mol), thymine (0.01 mol) to disaccharide acrylates (0.03 mol) was carried out in pyridine (20 ml) at 50 degrees C for 72 h with lipase M from Mucor javanicus (200 mg). Six new pyrimidine derivatives containing a branched sugar were obtained in yields from 56 to 75%.

Determination of furfural in an oscillating chemical reaction using an analyte pulse perturbation technique.

A rapid and convenient method for the determination of furfural is presented that is based upon sequential perturbation of the Mn(II)-catalyzed B-Z oscillating system with different amounts of furfural using a continuous-flow stirred tank reactor (CSTR). When the sample was injected, the change in the amplitude and/or period was linearly proportional to the logarithm of the concentration of furfural over the range 3 x 10(-8) approximately 1 x 10(-5) mol L(-1). This method gave a detection limit of 3 x 10(-9) mol L(-1) under optimum conditions. Finally, the possible mechanism of furfural perturbation in the oscillating reaction is discussed. When the furfural was injected into the Mn(II)-catalyzed B-Z oscillating system, the change in the amplitude and/or period was linearly proportional to the logarithm of the concentration of furfural over the range 3 x 10(-8)~1 x 10(-5) mol L(-1), with a detection limit of 3 x 10(-9) mol L(-1) under optimum conditions.

Improved sensitivity for some [corrected] metal ions by use of sulfide in the Belousov-Zhabotinskii oscillating reaction.

A highly sensitive method for the determination of trace amounts of some [corrected] metal ions by use of sulfide in the Belousov-Zhabotinskii (B-Z) oscillating chemical reaction is proposed. The use of sulfide increased strongly the sensitivity of the B-Z reaction for some [corrected] metal ions, such as Ag+, Pb2+, Hg2+, Cd2+, Cu2+, and Bi3+. Results showed that the variational ratio of oscillating period (P(R)) is linearly proportional to the negative logarithm of concentration of metal ions. The detection limit is down to 10(-12) mol L(-1). Various influencing factors on the determination were also examined.