Search

The improvement of Ag nanoparticles includes not only the antibacterial effect but also balancing the side effects from the antibacterial effect and osteogenesis properties, which can lead to an increased success rate of titanium implants.

Interfacial free energy is a quantitative basis for explaining and predicting interfacial behavior that is ubiquitous in nature. The contact angle (CA) method can determine the surface free energy (γ) as well as Lifshitz-van der Waals (γ

Jasmonates (JAs) are phospholipid-derived hormones that regulate plant development and responses to environmental stress. The synthesis of JAs and the transduction of their signaling pathways are precisely regulated at multiple levels within and outside the nucleus as a result of a combination of genetic and epigenetic regulation. In this review, we focus on recent advances in the regulation of JA biosynthesis and their signaling pathways. The biosynthesis of JAs was found to be regulated with an autocatalytic amplification mechanism via the MYC2 regulation pathway and inhibited by an autonomous braking mechanism via the MYC2-targeting bHLH1 protein to terminate JA signals in a highly ordered manner. The biological functions of JAs mainly include the promotion of fruit ripening at the initial stage via ethylene-dependent and independent ways, the regulation of mature coloring via regulating the degradation of chlorophyll and the metabolism of anthocyanin, and the improvement of aroma components via the regulation of fatty acid and aldehyde alcohol metabolism in agricultural crops. JA signaling pathways also function in the enhancement of biotic and abiotic stress resistance via the regulation of secondary metabolism and the redox system, and they relieve cold damage to crops through improving the stability of the cell membrane. These recently published findings indicate that JAs are an important class of plant hormones necessary for regulating plant growth and development, ripening, and the resistance to stress in agricultural crops and products.

Pelvic inflammatory disease (PID), a common infectious disease of the female reproductive tract, is mainly characterized by abdominal/pelvic pain and tenderness of the uterus, cervix, or adnexa on physical exam. In recent years, its incidence has gradually increased yearly due to numerous factors, including sexually transmitted diseases and intrauterine operations. Based on self-report of PID in the National Health and Nutrition Examination Survey (NHANES) 2013–2014 survey, PID impacts approximately 2.5 million women in the US during their reproductive age. Although empiric treatments such as antibiotics or surgery could alleviate the related symptoms of PID, its unsatisfactory obstetric outcome and high relapse bring heavy physical and psychological burden to women. Complementary and alternative medicine (CAM), a complementary therapy other than Western medicine with a complete theoretical and practical system, has been attached to importance in the world due to its remarkable efficacy. More people are accepting and trying to use CAM to treat gynecological diseases, including infertility, polycystic ovary syndrome, and PID, but its efficacy and mechanism are still controversial. This article reviews the previous literature systematically focusing on the effectiveness, safety, and mechanism of CAM in the treatment of PID to provide an evidence-based basis for the clinical application of CAM in patients with PID.

Skeletonema costatum is a common bloom-forming diatom and encounters eutrophication and severe carbon dioxide ( CO2 ) limitation during red tides. However, little is known regarding the role of phosphorus (P) in modulating inorganic carbon acquisition in S. costatum, particularly under CO2 limitation conditions. We cultured S. costatum under five phosphate levels (0.05, 0.25, 1, 4, 10 µ mol L −1) and then treated it with two CO2 conditions (2.8 and 12.6 µ mol L −1) for 2 h. The lower CO2 reduced net photosynthetic rate at lower phosphate levels ( µ mol L −1) but did not affect it at higher phosphate levels (4 and 10 µ mol L −1) . In contrast, the lower CO2 induced a higher dark respiration rate at lower phosphate levels (0.05 and 0.25 µ mol L −1) and did not affect it at higher phosphate levels (> 1 µ mol L −1) . The lower CO2 did not change relative electron transport rate (rETR) at lower phosphate levels (0.05 and 0.25 µ mol L −1) and increased it at higher phosphate levels (> 1 µ mol L −1) . Photosynthetic CO2 affinity (1/ K0.5) increased with phosphate levels. The lower CO2 did not affect photosynthetic CO2 affinity at 0.05 µ mol L −1 phosphate but enhanced it at the other phosphate levels. Activity of extracellular carbonic anhydrase was dramatically induced by the lower CO2 in phosphate-replete conditions (> 0.25 µ mol L −1) and the same pattern also occurred for redox activity of the plasma membrane. Direct bicarbonate ( HCO 3 - ) use was induced when phosphate concentration was more than 1 µ mol L −1 . These findings indicate P enrichment could enhance inorganic carbon acquisition and thus maintain the photosynthesis rate in S. costatum grown under CO2 -limiting conditions via increasing activity of extracellular carbonic anhydrase and facilitating direct HCO 3 - use. This study sheds light on how bloom-forming algae cope with carbon limitation during the development of red tides.

The application of anaerobic membrane bioreactors (AnMBRs) for wastewater treatment is seriously challenged by membrane fouling. Online monitoring of the fouling potential would promisingly support smart control of fouling. The monitoring is most likely achievable using spectroscopic methods, but the spectroscopic indicators are yet to be qualified. In this study, 11 ultraviolet (UV) indicators, 19 fluorescence excitation-emission matrix indicators and 2 infrared scattering indicators were screened during 151-day operation of a lab-scale AnMBR. The critical filtration volume for flux declining to 50% or 25% (V0.5 or V0.25) and the specific resistance (Kcf) were employed as benchmarks of fouling potential for initial pore blocking and subsequent gel/cake layer growth. The 254 and 280 nm UV absorbances (UV254 and UV280) displayed significant correlation coefficients of 0.57–0.77 with the fouling indexes, while the Peak 1 and Peak 2 fluorescence intensities (FIP1 and FIP2) displayed 0.84–0.92. Statistical variance partitioning and Fourier transform infrared analyses showed that polysaccharide-like solutes were mostly responsible for fouling and were UV/fluorescence-sensitive due to the chromophoric/fluorophoric segments they carried. X-ray photoelectron spectra revealed a correlation of fouling and fluorescence with the O=C-(R N O) content. Ultrahigh-performance liquid chromatography-mass spectrometry substantiated the direct connection of sugar units with chromophoric/fluorophoric groups. Regression models were then established to predict the fouling potential during AnMBR operation. The combined use of FIP1 and UV280 achieved the best prediction of V0.5, V0.25 and Kcf with R2 = 0.763, 0.891 and 0.845, respectively, showing the viability of spectroscopic sensing in membrane bioreactor applications.

A classical red tide alga Skeletonema costatum was cultured under various nitrate levels to investigate its physiological response to nitrate enrichment combined with CO2 limitation. The higher nitrate levels increased content of photosynthetic pigments (Chl a and Chl c), electron transport rate in photosystem II, photosynthetic O2 evolution, and thus growth rate in S. costatum. On the other hand, the lower CO2 levels (3.5-4.4 μmol kg-1 seawater) and higher pH (8.56-8.63) values in seawater were observed under higher nitrate conditions. Redox activity of plasma membrane and carbonic anhydrase in S. costatum was enhanced to address the reduced CO2 level at higher nitrate levels. In addition, the pH compensation point was enhanced and direct HCO3- use was induced at higher nitrate levels. These findings indicate that nitrate enrichment would stimulate the breakout of S. costatum dominated red tides via enhancing its photosynthetic performances, and maintain a quick growth rate under CO2 limitation conditions through improving its inorganic carbon acquisition capability. Our study sheds light on the mechanisms of S. costatum defeating CO2 limitation during algal bloom.

Excitation-emission matrix (EEM) fluorescence spectroscopy is a powerful tool for the characterization of dissolved organic matter (DOM) in wastewater systems. It is of particular value if its utility could be extended by connecting the spectral features to hydrophobicity, one of the fundamental physicochemical properties of DOM. In this study, we employed a DAX-8 resin column to fractionate the hydrophobic/philic components of DOM and determine the relative degree of hydrophobicity by adjusting the critical retention factor (k’cr, the ratio of treated water sample volume to column volume). A higher k’cr would result in a higher hydrophobicity of the column effluent. At different k’cr values (5, 10, 25, 50, 100, and 200), the EEM characteristics of the obtained DOM components were inspected, including overall properties (average fluorescence per total organic carbon and UV absorbance), regional properties (fluorescence regional integration (FRI) and its secondary parameters), and energy-related properties (energy level of the excited states, Stokes shift for relaxation of the excited states, and fluorescence lifetime). In case studies of a wastewater membrane bioreactor and an oxidation ditch, plenty of the EEM properties varied significantly with logk’cr (r > 0.9, p

The membrane bioreactor (MBR) technology is a rising star for wastewater treatment. The pollutant elimination and membrane fouling performances of MBRs are essentially related to the dissolved organic matter (DOM) in the system. Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy, a powerful tool for the rapid and sensitive characterization of DOM, has been extensively applied in MBR studies; however, only a limited portion of the EEM fingerprinting information was utilized. This paper revisits the principles and methods of fluorescence EEM, and reviews the recent progress in applying EEM to characterize DOM in MBR studies. We systematically introduced the information extracted from EEM by considering the fluorescence peak location/ intensity, wavelength regional distribution, and spectral deconvolution (giving fluorescent component loadings/scores), and discussed how to use the information to interpret the chemical compositions, physiochemical properties, biological activities, membrane retention/fouling behaviors, and migration/ transformation fates of DOM in MBR systems. In addition to conventional EEM indicators, novel fluorescent parameters are summarized for potential use, including quantum yield, Stokes shift, excited energy state, and fluorescence lifetime. The current limitations of EEM-based DOM characterization are also discussed, with possible measures proposed to improve applications in MBR monitoring.

Hydrophobicity and molecular weight (MW) are two fundamental properties of dissolved organic matter (DOM) in wastewater treatment systems. This study proposes fluorescence Stokes shift and specific fluorescence intensity (SFI) as novel indicators of hydrophobicity and MW. These indicators originate from the energy gap and photon efficiency of the fluorescence process and can be readily extracted from a fluorescence excitation-emission matrix (EEM). The statistical linkages between these indicators and hydrophobicity/MW were explored through investigation of DOM across 10 full-scale membrane bioreactors treating municipal wastewater. Stokes shift was found to exhibit a general rule among the hydrophobicity components in the order of hydrophilic substances (HIS) 100 kDa), SFI was found to be the most sensitive to the change of MW of 0.9). Hydrophobicity-related π conjugation and MW-dependent light exposure might be responsible for the correlations. These fluorescence indicators may be useful for convenient monitoring of DOM in wastewater treatment systems.

Biogas sparging is one of the most commonly used strategies for membrane fouling control in anaerobic membrane bioreactors (AnMBR). However, as a cost-effective sparging pattern, high/low alternate sparging mode was seldom studied, not to mention at a quantitative level. In this study, we systematically assessed the impacts of various parameters of gas sparging (intensity, duration and interval/frequency) on membrane fouling characteristics, on the basis of orthogonal tests coupled with statistical analysis of variance and covariance. The specific gas demand in the high-intensity phase (SGDH) was identified as the key factor impacting the overall fouling rate and stagewise rate constants (Kp’ and Kc’ for pore blocking and cake layer stages respectively) with negative correlation. The product of SGDH and time, i.e. the accumulative gas amount in the high-intensity phase (QH), was identified as the key factor affecting foulant layer reversibility (η) and specific resistance (α), with logarithmic models established in terms of log QH versus log η and log α. The validity and robustness of the quantitative models with definite physical meaning were evaluated via Monte Carlo simulation of the regression. The underlying mechanisms were explained from the perspective that hydrodynamic conditions influence mixed liquor and foulant properties (particle size distribution, microbial products amount and component) and, hence, affect fouling rates and foulant layer properties, with a panorama of the interrelated factors and properties delineated by multivariate analysis. This study is expected to provide a quantitative basis for the design of gas sparging conditions, under which sustainable operation of AnMBR could be achieved with the lowest energy consumption.

S. costatum is a common bloom-forming diatom and encounters eutrophication and severe CO2 limitation during red tides. However, little is known regarding the role of phosphorus in modulating inorganic carbon acquisition in S. costatum，particularly under CO2 limitation conditions. We cultured S. costatum under five phosphate levels (0.05, 0.25, 1, 4, 10 μmol L−1) and then treated it with two CO2 conditions (2.8 and 12.6 μmol L−1) for two hours. The lower CO2 reduced net photosynthetic rate at lower phosphate levels ( 1 μmol L−1). The lower CO2 did not change rETR at lower phosphate levels (0.05 and 0.25 μmol L−1) and increased it at higher phosphate levels (> 1 μmol L−1). Photosynthetic CO2 affinity (K0.5) decreased with phosphate levels. The lower CO2 did not affect K0.5 at 0.05 μmol L−1 phosphate but reduced it at the other phosphate levels. Activity of extracellular carbonic anhydrase was dramatically induced by the lower CO2 at phosphate replete conditions (> 0.25 μmol L−1) and the same pattern also occurred for redox activity of plasma membrane. Direct HCO3− use was induced when phosphate concentration is more than 1 μmol L−1. This study indicates the essential role of P in regulating inorganic carbon acquisition and CO2 concentrating mechanisms (CCMs) in S. costatum and sheds light on how bloom-forming algae cope with carbon limitation during the development of red tides.

A green synthetic method for 1,5‐disubstituted carbohydrazones is described. The reaction of dimethyl carbonate with hydrazine hydrate first gave carbohydrazide, which further reacted with various aromatic aldehydes or aliphatic ketones under solvent‐free conditions to efficiently afford 1,5‐disubstituted carbohydrazone. This protocol has the advantages of using nontoxic dimethyl carbonate as starting material, no use of organic solvents, short reaction time, high yield, and simple workup procedure.

A rapid method to N-acyl ureas from corresponding N-acyl thioureas is described. N-coumaroyl-N′-arylthioureas, which are easily prepared by the reaction of coumarin-3-carboxylic acid chloride with potassium thiocyanate and arylamines, can be expeditiously transformed into corresponding N-acyl ureas via r.t. grinding with wet silica supported potassium permanganate under solvent-free conditions in an excellent yield.

Poly(ethylene glycol) (PEG) supported dichlorophosphate was efficiently used as a recoverable new dehydration reagent for rapid synthesis of 2-amino-5-substituted-1,3,4-thiadiazoles under microwave irradiation and solvent-free condition by reactions of thiosemicarbazide with aliphatic acids, benzoic acid, aryloxyacetic acids or furan-2-carboxylic acids.

By analyzing the influence factors of the laser range finder LMS200 based on the robot navigation, this paper researches the range finder application with LMS200 respectively from two aspects of indoor and outdoor under different conditions. The index of reflection, the target surface properties, the mix picture element, and the visibility as well as the laser transmission atmospheric effect and so on the environmental factor which really affect the actual survey application are studied. The rangefinder experiment effects under the different factors are illustrated by experimental contrast, the methods to reduce the influences of various factors are given out and all the results could lay a foundation for carrying on precise rangefinder application of the robot navigation.

This paper describes the implementation of serial communication between the PLC and the host-computer in the control system of waste water pump, gives a detailed introduction to the communication protocols and parameters setting and also gives part of the serial-communication program based on visual basic 6.0. Pratice shows that this control system meets the requirements as expected, attains management without human, which reduces the operating cost of the water pump.

2‐Aryl‐5‐(coumarin‐3′‐yl)‐1,3,4‐oxadiazoles are efficiently synthesized by microwave accelerated solvent‐free procedure in high yield via the condensation of coumarin‐3‐carboxylic acid with (un)substituted benzoic acid hydrazides using poly(ethylene glycol) (PEG) supported dichlorophosphate as dehydration reagent.