Association between hemoglobin A1c trajectory during pregnancy and adverse birth outcomes among non-gestational diabetic women.

AIMS: Previous studies have shown that higher hemoglobin A1c (HbA1c) levels within the normal range during pregnancy can increase the risk of adverse birth outcomes. However, the effects of the longitudinal HbA1c trajectory during pregnancy on adverse birth outcomes among non-gestational diabetic women are poorly characterized. We aimed to identify HbA1c trajectory during pregnancy among non-gestational diabetic women and to estimate their associations with adverse birth outcomes. METHODS: Data was extracted from the Information System of Guangdong Women and Children Hospital, China, from January 2017 to July 2022. This study involved 13,979 women who did not have gestational diabetes mellitus and underwent repeated HbA1c measurements during pregnancy. Latent mixture modeling was used to identify HbA1c trajectory groups. Logistic regression was applied to explore the associations between HbA1c trajectory groups and adverse birth outcomes, including preterm delivery, low birth weight, macrosomia, small for gestational age, and large for gestational age (LGA). RESULTS: Three HbA1c trajectory groups were identified: low-stable (range 4.0% [20 mmol/mol]-4.4% [25 mmol/mol]), moderate-stable (range 4.6% [27 mmol/mol]-5.1% [32 mmol/mol]), and elevated-increasing (range 5.0% [31 mmol/mol]-5.6% [38 mmol/mol]). Compared with the low-stable HbA1c group, the elevated-increasing group had a higher risk of preterm delivery and LGA. The adjusted OR (95% CIs) were 1.67 (1.13, 2.49) and 1.47 (1.01, 2.12) for preterm delivery and LGA, respectively. CONCLUSIONS: Among non-gestational diabetic women, the elevated-increasing HbA1c trajectory group was associated with a higher risk of preterm delivery and LGA. This finding emphasizes the importance of maintaining optimal HbA1c levels throughout pregnancy.

Analysis of Breast Cancer Screening Results and Influencing Factors of Breast Cancer in Guangdong Province from 2017 to 2021.

BACKGROUNDS: Breast cancer screening plays an important role in the early detection, diagnosis and treatment of breast cancer. The aim of this study was to evaluate the screening results and explore the influencing factors of breast cancer detection rate in Guangdong. METHODS: This cross-sectional study was conducted among 2,024,960 women aged 35-64 in Guangdong Province during 2017-2021. The data about breast cancer screening information were collected from the Guangdong maternal and child health information system. Descriptive statistical analysis was used to explain demographic characteristics and results of breast cancer screening. The generalized linear regression model was applied to analyze the related influencing factors of breast cancer detection rate. RESULTS: The estimated detection rate of breast cancer in Guangdong Province is 70.32/105, with an early diagnosis rate of 82.06%. After adjusting covariates, those women with older age (45-55 [OR (95% CI) 2.174 (1.872, 2.526)], 55-65 [OR (95% CI) 2.162 (1.760, 2.657)]), education for high school ([OR (95% CI) 1.491 (1.254, 1.773)]) and older age at first birth ([OR (95% CI) 1.632 (1.445, 1.844)]) were more likely to have higher detection rate of breast cancer. No history of surgery or biopsy ([OR (95% CI) 0.527 (0.387, 0.718)]), no history of breast cancer check ([OR (95% CI) 0.873 (0.774, 0.985)]) and no family history of breast cancer ([OR (95% CI) 0.255 (0.151, 0.432)]) women were more likely to screen negative for breast cancer (P < 0.05). CONCLUSION: The detection rate of breast cancer in screening showed an increasing trend year by year in Guangdong Province. Older age, education for high school and older age at first birth were risk factors for breast cancer detection rate, while no surgery or biopsy history, no family history of breast cancer and no history of breast cancer check were protective factors.

Performance of quantum-dash mode-locked lasers (QD-MLLDs) for high-capacity coherent optical communications.

We investigate the capabilities and limitations of quantum-dash mode-locked lasers (QD-MLLDs) as optical frequency comb sources in coherent optical communication systems. We demonstrate that QD-MLLDs are on par with conventional single-wavelength narrow linewidth laser sources and can support high symbol rates and modulation formats. We manage to transmit 64 quadrature amplitude modulation (QAM) signals up to 80 GBd over 80 km of standard single-mode fiber (SSMF), which highlights the distinctive phase noise performance of the QD-MLLD. Using a 38.5 GHz (6 dB bandwidth) silicon photonic (SiP) modulator, we achieve a maximum symbol rate of 104 GBd with 16QAM signaling and a maximum net rate of 416 Gb/s per carrier in a single polarization setup and after 80 km-SSMF transmission. We also compare QD-MLLD performance with commercial narrow-linewidth integrable tunable laser assemblies (ITLAs) and explore their potential for use as local oscillators (LOs) and signal carriers. The QD-MLLD has 45 comb lines usable for transmission at a frequency spacing of 25 GHz, and an RF linewidth of 35 kHz.

Safe utilization of bioresources in gentamicin mycelial residues by thermal treatment: Antibiotic degradation, resistance gene inactivation and available nutrients promotion.

Gentamicin mycelium residues (GMRs) abundant in organic substances were generated during the production of gentamicin. Inappropriate handling techniques not only waste valuable resources, they could also result in residual gentamicin into the natural environment, leading to the generation of antibiotic resistance genes (ARGs), which would cause a significant threat to ecological system and human health. In the present work, the effects of thermal treatment on the removal of residual gentamicin in GMRs, as well as the changes of associated ARGs abundance, antimicrobial activity and bioresources properties were investigated. The results indicated that the hazards of GMRs was significantly reduced through thermal treatment. The degradation rate of residual gentamicin in GMRs reached 100 %, the total abundance of gentamicin resistance genes declined from 8.20 to 1.14 × 10-5 and the antibacterial activity of the decomposition products of GMRs on Vibrio fischeri was markedly reduced at 200 °C for 120 min. Additionally, the thermal treatment remarkably influenced the bioresource properties of GMRs-decomposition products. The release of soluble organic matters including soluble carbohydrates and soluble proteins have been enhanced in GMRs, while excessively high temperatures could lead to a reduction of nutrient substances. Generally, thermal treatment technology was a promising strategy for synergistic reducing hazards and utilizing bioresources of GMRs.

Heat and carbon co-activated persulfate to regenerate gentamicin-laden activated carbon: Performance, mechanism, and safety assessment.

Activated carbon enriched with high concentrations of gentamicin (ACG) was generated in the production process of gentamicin. Inappropriate handling methods for ACG not only squanders carbon resource, but also seriously hinders achieving global carbon neutrality and hazardous to human health. In the present work, thermal and carbon co-activated persulfate method (TC-PS) was developed to regenerate ACG with degrading gentamicin. The results showed that ACG was effectively regenerated by TC-PS, restoring the adsorption performance for gentamicin. When the treatment temperature was 80 °C, the persulfate dosage was 20 mM and the initial pH was 3.0, the degradation efficiency of gentamicin reached 100%. The HO• and SO4•- were the major reactive species for gentamicin degradation. The possible degradation routes of gentamicin were proposed and the safety assessment indicated that the produced intermediates during the regeneration process of ACG by TC-PS have insignificant impact on the biological and ecological environment.

In-situ production and activation of H2O2 over hydroxyapatite modified CuFeO2 for self-sufficient heterogeneous photo-Fenton degradation of doxycycline hydrochloride.

The self-sufficient heterogeneous photo-Fenton (SH-PF) system was constructed for doxycycline hydrochloride (DOH) degradation with hydroxyapatite (Hap) modified CuFeO2 (Hap/CuFeO2) composites through H2O2 in-situ production. The modification of Hap could improve the specific surface area, visible-light response, light conversion efficiency, photoelectron lifetime and oxygen vacancies (OVs) of CuFeO2, which was conducive to H2O2 production and DOH degradation in SH-PF system. Notably, Hap/CuFeO2 fabricated with 0.5 g Hap (Hap/CuFeO2-0.5) displayed more superior performance for DOH degradation compared to other synthesized catalysts. The Hap/CuFeO2-0.5 load and initial solution pH for DOH degradation in SH-PF system were optimized, and the Hap/CuFeO2-0.5 had good reusability and stability. The •OH was the main active species for DOH degradation, and the facilitation effect of •O2- and photoelectrons on DOH degradation was associated with the H2O2 production in the present work. In addition, the capture of photogenerated holes suppressed the recombination of photogenerated carriers, elevating the production of photoelectrons and thereby enhancing H2O2 production and DOH degradation. The degradation pathways for DOH were proposed and the comprehensive toxicities of DOH were relieved after degradation in SH-PF system.

Epigenetic phenotype of plasma cell-free DNA in the prediction of early-onset preeclampsia.

BACKGROUND: In the current study, we sought to characterise the methylation haplotypes and nucleosome positioning patterns of placental DNA and plasma cell-free DNA of pregnant women with early-onset preeclampsia using whole genome bisulphite sequencing (WGBS) and methylation capture bisulphite sequencing (MCBS) and further develop and examine the diagnostic performance of a generalised linear model (GLM) by incorporating the epigenetic features for early-onset preeclampsia. METHODS: This case-control study recruited pregnant women aged at least 18 years who delivered their babies at our Hospital. In addition, non-pregnant women with no previous history of diseases were included. Placental samples of the villous parenchyma were taken at the time of delivery and venous blood was drawn from pregnant women during non-invasive prenatal testing at 12-15 weeks of pregnancy and nonpregnant women during the physical check-up. WGBS and MCBS were carried out of extracted genomic DNA. Then, we established the GLM by incorporating preeclampsia-specific methylation haplotypes and nucleosome positioning patterns and examined the diagnostic performance of the model by receiver operating characteristic (ROC) curve analysis. RESULTS: The study included 135 pregnant women and 50 non-pregnant women. Our high-depth MCBS revealed notably different DNA methylation and nucleosome positioning patterns between women with and without preeclampsia. Preeclampsia-specific hypermethylated sites were found predominantly in the promoter regions and particularly enriched in CTCF on the X chromosome. Totally, 2379 preeclampsia-specific methylation haplotypes were found across the entire genome. ROC analysis showed that the area under the ROC curve (AUC) was 0.938 (95%CI 0.877, 1.000). At a GLM cut-off of 0.341, the AUC was the maximum, with a sensitivity of 95.6% and a specificity of 89.7%. CONCLUSION: Pregnant women with early-onset preeclampsia exhibit DNA methylation and nucleosome positioning patterns in placental and plasma DNA.

Early-onset preeclampsia is a potentially dangerous condition that can have a profound impact on the health of both the expectant mother and her unborn child. This condition is particularly concerning because it's challenging to predict who may be affected using conventional methods such as monitoring blood pressure. In our research, we've developed an innovative, non-invasive approach to predict the onset of early preeclampsia. We do this by analysing the genetic material of the developing baby, which can be found in the mother's blood. Our method has shown remarkable accuracy in our testing populations, and its implications are substantial. By providing an early warning system, this breakthrough can benefit pregnant women immensely. It means that early-onset preeclampsia can be identified and addressed well before it becomes a serious health threat. This allows for timely medical interventions and treatments, significantly improving the well-being of both mothers and their precious little ones.

Performance Investigations of InAs/InP Quantum-Dash Semiconductor Optical Amplifiers with Different Numbers of Dash Layers.

We present here a performance comparison of quantum-dash (Qdash) semiconductor amplifiers (SOAs) with three, five, eight, and twelve InAs dash layers grown on InP substrates. Other than the number of Qdash layers, the structures were identical. The eight-layer Qdash SOA gave the highest amplified spontaneous emission power (4.3 dBm) and chip gain (26.4 dB) at 1550 nm, with a 300 mA CW bias current and at 25 °C temperature, while SOAs with fewer Qdash layers (for example, three-layer Qdash SOA), had a wider ASE bandwidth (90 nm) and larger 3 dB gain saturated output power (18.2 dBm) in a shorter wavelength range. The noise figure (NF) of the SOAs increased nearly linearly with the number of Qdash layers. The longest gain peak wavelength of 1570 nm was observed for the 12-layer Qdash SOA. The most balanced performance was obtained with a five-layer Qdash SOA, with a 25.4 dB small-signal chip gain, 15.2 dBm 3 dB output saturated power, and 5.7 dB NF at 1532 nm, 300 mA and 25 °C. These results are better than those of quantum well SOAs reported in a recent review paper. The high performance of InAs/InP Qdash SOAs with different Qdash layers shown in this paper could be important for many applications with distinct requirements under uncooled scenarios.

[Adsorption Characteristics of Tetracycline by CuFeO2-modified Biochar].

CuFeO2-modified biochars were prepared through co-precipitation and hydrothermal methods, and the composites had high efficiency removal for tetracycline (TC) from water. The CuFeO2-modified biochar with a 2:1 mass ratio of CuFeO2 to BC450 (CuFeO2/BC450=2:1) demonstrated the best adsorption performance. The kinetic process of TC adsorption by CuFeO2/BC450=2:1 was well fitted with the intraparticle diffusion model, suggesting that the adsorption process was controlled by film and pore diffusion. Under the condition of neutral pH and 298 K, the maximum adsorption capacity of the Langmuir model of CuFeO2/BC450=2:1 was 82.8 mg·g-1, which was much greater than that of BC450 (13.7 mg·g-1) and CuFeO2(14.8 mg·g-1). The thermodynamic data suggested that TC sorption onto CuFeO2/BC450=2:1 was a spontaneous and endothermic process. The removal of TC by CuFeO2/BC450=2:1 increased first and then decreased with increasing pH, and the maximum adsorption occurred under the neutral condition. The strong adsorption of TC by CuFeO2/BC450=2:1 could be attributed to better porosity, larger specific surface area, and more active sites (e.g., functional groups and charged surfaces). This work provided an efficient magnetic adsorbent for removing antibiotics.

Insight into the absorption and migration of polystyrene nanoplastics in Eichhornia crassipes and related photosynthetic responses.

Nanoplastics, as emerging contaminants are being released into aquatic environments with their increasing applications, and induce potential hazards to aquatic ecosystem. In this work, we investigated the removal process of polystyrene nanoparticles (PS NPs) by Eichhornia crassipes and the related photosynthetic responses of E. crassipes. Results showed that both sizes of PS NPs (20 and 200 nm) with 50 mg/L induced the prominent damage on the root epidermis after 48 h exposure, and smaller size PS NPs caused the greater damage. PS NPs has been entered the roots of E. crassipes and migrated from the epidermis, cortex, to vascular system by using confocal laser scanning microscopy observation. Scanning electron microscope images confirmed the distribution of PS NPs (200 nm) in the roots. The crack at sites of primary-lateral root junction was an important way for the uptake of PS NPs, which destroyed the defense of Casparian strip, and promoted the migration of PS NPs into the vascular system. PS NPs entered the submerged leaves by stomata and the intercellular spaces of lower epidermis. Moreover, PS NPs in the plants showed significant inhibition on net photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate. This study concluded the absorption and migration processes of PS NPs by E. crassipes, and the negative effects on photosynthesis, which will be useful for guiding the floating plants application for PS NPs removal in aqueous environment and ecological improvement.

Highly efficient nanocomposite of Y2O3@biochar for oxytetracycline removal from solution: Adsorption characteristics and mechanisms.

Nano Y2O3-modified biochar composites (Y2O3@BC600) were fabricated successfully and exhibited great adsorption toward oxytetracycline (OTC). The Langmuir adsorption capacity of Y2O3@BC600-1:4 for OTC reached 223.46 mg/g, 10.52 times greater than that of BC600. The higher dispersion of Y2O3 nanoparticles, increased surface area of 175.65 m2/g and expanded porosity of 0.27 cm3/g accounted for higher OTC adsorption by Y2O3@BC600-1:4. Y2O3@BC600-1:4 could resist the interference of co-existing cations (Na+, K+, Mg2+, Ca2+) and anions (Cl-, NO3-, SO42-) on OTC removal. Y2O3 coating changed surface charge property of BC600, favoring the contribution of electrostatic interaction. Synchrotron radiation-based Fourier transform infrared spectroscopy detected obvious peak shift and intensity change of surface -OH when OTC adsorption occurred. Accordingly, stronger H-bonding (charge-assisted hydrogen bond, OTC-H2N+···HO-Y2O3@BC600-1:4) was proposed for OTC adsorption. Y2O3@BC600 exhibited renewability and stability in the adsorptive removal of OTC. Therefore, Y2O3@BC600 may be a novel and suitable adsorbent for antibiotic removal.

Fenton oxidation treatment of oxytetracycline fermentation residues: Harmless performance and bioresource properties.

The pharmaceutical factories of oxytetracycline (OTC) massively produce OTC fermentation residues (OFRs). The high content of residual OTC and antibiotic resistance genes in OFRs must to be considered and controlled at an acceptable level. This study therefore investigated the applicability of Fenton oxidation in OTC degradation and resistant gene inactivation of OFRs. The results revealed that Fe2+ as catalyzer could very rapidly activate H2O2 to produce HO•, leading to instantaneous degradation of OTC. The optimum conditions for OTC removal were 60 mM H2O2 and 140 mg/L Fe2+ under pH 7. After Fenton oxidation treatment, the release of water-soluble polysaccharides, NO3-N, and PO4-P was enhanced, whereas for proteins and NH3-N were reduced. Three soluble fluorescence components (humic, tryptophan-like, and humic acid-like substances) were identified through fluorescence spectra with parallel factor analysis, and their reduction exceeded 50% after Fenton oxidation. There were twelve intermediates and three degradation pathways of OTC in OFRs during Fenton process. According to toxicity prediction, the comprehensive toxicity of OTC in OFRs was alleviated via Fenton oxidation treatment. In addition, Fenton oxidation showed the ability to reduce antibiotic resistance genes and mobile genetic elements, and even tetO, tetG, intI1, and intI2 were eliminated completely. These results suggested that Fenton oxidation treatment could be an efficient strategy for removing OTC and resistance genes in OFRs.

Efficiency and mechanism on photocatalytic degradation of fluoranthene in soil by Z-scheme g-C3N4/α-Fe2O3 photocatalyst under simulated sunlight.

Polycyclic aromatic hydrocarbons (PAHs) in soil have potential harm on human health. However, remediation of PAH-contaminated soils through photocatalytic technology remains a challenge. Therefore, the photocatalyst g-C3N4/α-Fe2O3 was synthesized and applied to photocatalytic degradation of fluoranthene in soil. The physicochemical properties of g-C3N4/α-Fe2O3 and various degradation parameters, such as catalyst dosage, the ratio of water/soil, and initial pH, were investigated in detail. In soil slurry reaction system (water/soil=10:1, w/w), the optimal degradation efficiency on fluoranthene was 88.7% after simulated sunlight irradiation for 12 h (contaminated soil=2 g, initial fluoranthene concentration=36 mg/kg, catalyst dosage=5%, and pH=6.8), and the photocatalytic degradation followed pseudo-first-order kinetics. The degradation efficiency of g-C3N4/α-Fe2O3 was higher compared with P25. Degradation mechanism analysis showed that •O2- and h+ are the main active species in photocatalytic degradation process of fluoranthene by g-C3N4/α-Fe2O3. Coupling g-C3N4 and α-Fe2O3 enhances the interfacial charge transport capacity via Z-scheme charge transfer route and inhibits the recombination of photogenerated electrons and holes of g-C3N4 and α-Fe2O3, then significantly improves the production of active species and photocatalytic activity. Results showed that photocatalytic treatment of soil by g-C3N4/α-Fe2O3 is an effective strategy for remediation of soils contaminated by PAHs.

Stable Zinc(II) Coordination Polymer as a Rapid and Highly Sensitive Fluorescence Sensor for the Discriminative Sensing of Biomarker 2-(2-Methoxyethoxy) Acetic Acid.

A novel two-dimensional bilayer Zn-based luminescent coordination polymer (LCP) [Zn2(µ2-OH)(4-dptp)(3,4',5-bpt)] (LCP 1) [4-dptp = N3,N4-bis(pyridin-4-ylmethyl)thiophene-3,4-dicarboxamide and 3,4',5-H3bpt = biphenyl-3,4',5-tricarboxylic acid] was successfully prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, powder X-ray diffraction, and luminescence spectroscopy. LCP 1 displayed excellent fluorescence-quenching efficiency toward a biomarker 2-(2-methoxyethoxy) acetic acid (MEAA) with a high Ksv (5.153 × 104 M-1), a low limit of detection (0.244 µM), and a rapid response time (28 s). Additionally, LCP 1 can repeatedly detect MEAA at least eight times with excellent stability. The sensing mechanism was also carefully investigated through UV-vis absorption spectroscopy, density functional theory calculations, and fluorescence lifetime analysis.

InAs/InP quantum dot mode-locked laser with an aggregate 12.544 Tbit/s transmission capacity.

Chip-scale optical frequency comb sources are ideal compact solutions to generate high speed optical pulses for applications in wavelength division multiplexing (WDM) and high-speed optical signal processing. Our previous studies have concentrated on the use of quantum dash based lasers, but here we present results from an InAs/InP quantum dot (QDot) C-band passively mode-locked laser (MLL) for frequency comb generation. By using this single-section QDot-MLL we demonstrate an aggregate line rate of 12.544 Tbit/s 16QAM data transmission capacity for both back-to-back (B2B) and over 100-km of standard single mode fiber (SSMF). This finding highlights the viability for InAs/InP QDot lasers to be used as a low-cost optical source for large-scale networks.

In-situ electrodeposition synthesis of Z-scheme rGO/g-C3N4/TNAs photoelectrodes and its degradation mechanism for oxytetracycline in dual-chamber photoelectrocatalytic system.

The dual-chamber photoelectrocatalytic (PEC) system possess advantages in the degradation efficiency and processing cost of organic contaminants. In this study, TiO2 nanotube arrays modified by rGO and g-C3N4 (rGO/g-C3N4/TNAs) photoelectrodes were successfully prepared. The surface micromorphology, chemical structure, crystal structure, and basic element composition of rGO/g-C3N4/TNAs photoelectrodes were studied by SEM, FTIR, XRD, Raman, and XPS. UV-vis absorption, photoluminescence (PL) spectra, and photoelectrochemical (PECH) tests were used to explore the photoelectrochemical characteristics of rGO/g-C3N4/TNAs photoelectrodes. Under simulated sunlight illumination, the dual-chamber PEC system with external bias voltage was used to investigate the degradation of oxytetracycline (OTC) on rGO/g-C3N4/TNAs photoelectrodes. The results showed that rGO and g-C3N4 were successfully loaded on TNAs, and the separation efficiency of electrons and holes at rGO/g-C3N4/TNAs photoelectrodes was improved. The light absorption range of rGO/g-C3N4/TNAs photoelectrodes extends to the visible light region and has better light absorption performance. Compared with the photocatalytic process, when 1.2 V bias voltage was applied, the degradation efficiency of OTC in anode and cathode chambers in PEC were increased by 3.28% and 44.01% within 60 min, respectively. In addition, the anode and cathode chambers have different degradation effects on OTC. Both the external bias voltage and initial pH have significant effects in cathode chamber, but have little effect in photoanode chamber. The fluorescence excitation-emission matrix spectra and liquid chromatography-tandem mass spectrometry showed that there were different intermediates in the degradation process of OTC. This study indicated that for the dual-chamber PEC system, rGO/g-C3N4/TNAs photoelectrodes exhibited excellent photocatalytic performance and have potential application prospects in water environmental remediation.

Degradation of rifamycin from mycelial dreg by activated persulfate: Degradation efficiency and reaction kinetics.

Rifamycin mycelial dreg (RMD) is a biological waste, and its residual rifamycin (RIF) is potentially harmful to both the environment and human health. In this work, thermally activated persulfate (PDS) oxidative degradation of RIF in RMD was developed for the first time. The effects of reaction temperature, initial PDS concentration, and pH on RIF degradation in RMD were investigated, and the treatment conditions were optimized using response surface methodology (RSM). The results showed that 90 °C, 50 mg/g PDS, and pH = 5.3 were the optimal pretreatment conditions, and 100% degradation efficiency of RIF (734 mg/kg) was achieved. SEM and FTIR analyses confirmed that the RIF was destroyed and decomposed after the oxidation reaction. The possible degradation pathways of RIF in the thermally activated PDS system were discussed through HPLC/MS and ESR analyses. The intermediate product was identified, and the toxicity of the final product was predicted to be low or nontoxic. In this work, a degradation pathway of RMD was proposed by activating persulfate, which facilitates subsequent resource utilization and provides meaningful guidance for the practical treatment of antibiotic mycelium residue (AMR).

Highly-stable cobalt metal organic framework with sheet-like structure for ultra-efficient water oxidation at high current density.

The development of efficient and robust non-precious electrocatalysts for water oxidation at a mild condition is extremely desirable for industrial water splitting. Herein we developed a facile solvothermal strategy to synthesize cobalt metal organic frameworks (Co-MOFs) with sheet-like structure, which showed highly promising performance for electrocatalytic oxygen evolution. The best Co-MOF sample afforded an ultra-high oxygen evolution current density of 63.4 mA cm-2 at 1.75 V in 1 M KOH with a catalyst loading of only 0.21 mg cm-2. Notably, its electrochemical performance remained unchanged after 10,000 cyclic voltammograms indicating very promising long-term stability. Detailed study of the mechanism of the oxygen evolution by density functional theory (DFT) indicated that the strong π-conjugation formed between the central cobalt ion and adjacent aromatic rings favored the high electrocatalytic performance. The solvothermally synthesized MOFs proposed in this paper are expected to inspire the rational design of high-performance electrocatalysts for water oxidation with atomic and molecular level structural control and the exploration of structure-performance relationships to understand the electrocatalytic origin.

Investigating the effects of biochar colloids and nanoparticles on cucumber early seedlings.

Understanding about the influence of biochar colloidal and nanoscale particles on plant is limited. We therefore extracted the colloids and nanoparticles from hot pepper stalk biochar (CB600 and NB600), and examined physiological responses of cucumber early seedlings through hydroponic culture and pot experiment. CB600 had no significant effect on shoot at 500 mg/L, while it decreased root biomass and inhibited lateral root development. The biomass and root length, area, and tip number dramatically reduced after 500 mg/L NB600 treatment. Water content of NB600-exposed shoot was lower, suggesting water uptake and transfer might be hindered. For resisting exposure stress, root hair number and length increased. Even, the study observed swelling and hyperplasia of root hairs after direct exposure of CB600 and NB600. These adverse effects might be associated with the contact and adhesion of CB600 and NB600 with sharp edges to root surface. For a low concentration of 50 mg/L, NB600 did not influence cucumber early seedlings. In soil, CB600 and NB600 did not cause inhibitory effect at relatively high contents of 500 mg/kg and 2000 mg/kg. This study provides useful information for understanding phytotoxicity and environmental risk of biochar colloids and nanoparticles, which has significant implications with regard to biochar application safety.