Reactive oxygen and nitrogen species regulate porcine embryo development during pre-implantation period:A mini-review

Significant porcine embryonic loss occurs during conceptus morphological elongation and attachment from d 10 to 20 of pregnancy,which directly decreases the reproductive efficiency of sows.A successful establishment of pregnancy mainly depends on the endometrium receptivity,embryo quality,and utero-placental microenvironment,which requires complex cross-talk between the conceptus and uterus.The understanding of the molecular mechanism regulating the uterine-conceptus communication during porcine conceptus elongation and attachment has developed in the past decades.Reactive oxygen and nitrogen species,which are intracellular reactive metabolites that regulate cell fate decisions and alter their biological functions,have recently reportedly been involved in porcine conceptus elongation and attachment.This mini-review will mainly focus on the recent researches about the role of reactive ox-ygen and nitrogen species in regulating porcine embryo development during the pre-implantation period.

Effect of low-temperature plasma on the degradation of omethoate residue and quality of apple and spinach

Dielectric barrier corona discharge was developed to generate low-temperature plasma(LTP) to treat apple and spinach samples contaminated with omethoate. Experimental results showed that,after 20 min exposure, the degradation rate of omethoate residue in apple and spinach was(94.55± 0.01)% and(95.55 ± 0.01)%, respectively. When the treatment time was shorter than 20 min,the contents of moisture, vitamin C and beta-carotene were not affected by LTP. Exploration of related mechanisms suggested that LTP might destroy unsaturated double bonds of omethoate and produce phosphate ion, eventually leading to omethoate destruction. It is concluded that appropriate dosage of LTP can effectively degrade omethoate residue in fruits and vegetables without affecting their quality.

Quality enhancement and microbial reduction of mung bean(Vigna radiata)sprouts by non-thermal plasma pretreatment of seeds

Mung bean(Vigna radiata)sprouts are widely consumed worldwide due to their high nutritional value.However,the low yield and microbial contamination of mung bean sprouts seriously reduces their economic value.This study investigates the effects of non-thermal plasma on the quality and microbial reduction of mung bean sprouts by pretreatment of seeds in water for different times(0,1,3 and 6 min).The quality results showed that short-time plasma treatment(1 and 3 min)promoted seed germination and seedling growth,whereas long-time plasma treatment(6 min)had inhibitory effects.Plasma also had a similar dose effects on the total flavonoid and phenolic contents of mung bean sprouts.The microbiological results showed that plasma treatment achieved a reduction of native microorganisms ranging from 0.54 to 7.09 log for fungi and 0.29 to 6.80 log for bacteria at 96 h incubation.Meanwhile,plasma treatment could also efficiently inactivate artificially inoculated Salmonella typhimurium(1.83–6.22 log)and yeast(0.53–3.19 log)on mung bean seeds.The results of seed coat permeability tests and scanning electron microscopy showed that plasma could damage the seed coat structure,consequently increasing the electrical conductivity of mung bean seeds.The physicochemical analysis of plasma-treated water showed that plasma generated various long-and short-lived active species[nitric oxide radicals(NO·),hydroxyl radicals(·OH),singlet oxygen(1O2),hydrogen peroxide(H_(2)O_(2)),nitrate(NO_(3)^(-)),and nitrite(NO_(2)^(-))]in water,thus the oxidizability,acidity and conductivity of plasma-treated water were all increased in a treatment timedependent manner.The result for mimicked chemical mixtures confirmed the synergistic effect of activity of H_(2)O_(2),NO_(3)^(-)and NO_(2)^(-)on bacterial inactivation and plant growth promotion.Taken together,these results imply that plasma pretreatment of mung bean seeds in water with moderate oxidizability and acidity is an effective method to improve the yield of mung bean sprouts and reduce microbial contamination.

Effects of COD/N ratio and DO concentration on simultaneous nitrification and denitrification in an airlift internal circulation membrane bioreactor

The effects of chemical oxygen demand and nitrogen(COD/N)ratio and dissolved oxygen concentration(DO)on simultaneous nitrification and denitrification(SND)were investigated using an airlift internal circulation membrane bioreactor(AIC-MBR)with synthetic wastewater.The results showed that the COD efficiencies were consistently greater than 90% regardless of changes in the COD/N ratio.At the COD/N ratio of 4.77 and 10.04,the system nitrogen removal efficiency became higher than 70%.However,the nitrogen remova...

Recent advances and applications of single atom catalysts based electrochemical sensors

Single atom catalysts(SACs)have attracted considerable attention due to their unique structures and excellent catalytic performance,especially in the area of catalysis science and energy conversion and storage.In recent years,SACs have emerged as a new type of sensing material for constructing electrochemical sensors(ECSs),presenting excellent sensitivity,selectivity,and stability.Herein,we review the recent advances of SACs in electrochemical sensing and discuss the status quo of current SAC-based ECSs.Specifically,the fundamentals of SAC-based ECSs are outlined,including the involved central metal atoms and various supports of SACs in this field,the detection mechanisms,and improving strategies of SAC-based ECSs.Moreover,the important applications of SAC-based ECSs are listed and classified,covering the detection of reactive oxygen and nitrogen species,environmental pollutants,disease biomarkers,and pharmaceuticals.Last,based on abundant reported cases,the current conundrums of SAC-based ECSs are summarized,and the prediction of their future developing trends is also put forward.

Single-atom cobalt nanozymes promote spinal cord injury recovery by anti-oxidation and neuroprotection

Oxidative stress and inflammation are central pathophysiological processes in a traumatic spinal cord injury(SCI).Antioxidant therapies that reduce the reactive oxygen and nitrogen species(RONS)overgeneration and inflammation are proved promising for improving the outcomes.However,efficient and long-lasting antioxidant therapy to eliminate multiple RONS with effective neuroprotection remains challenging.Here,a single-atom cobalt nanozyme(Co-SAzyme)with a hollow structure was reported to reduce the RONS and inflammation in the secondary injury of SCI.Among SAzymes featuring different single metal-N sites(e.g.,Mn,Fe,Co,Ni,and Cu),this Co-SAzyme showed a versatile property to eliminate hydrogen peroxide(H_(2)O_(2)),superoxide anion(O_(2)·^(-)),hydroxyl radical(·OH),nitric oxide(·NO),and peroxynitrite(ONOO^(-))that overexpressed in the early stage of SCI.The porous hollow structure also allowed the encapsulation and sustained release of minocycline for neuroprotection in synergy.In vitro results showed that the Co-SAzyme reduced the apoptosis and pro-inflammatory cytokine levels of microglial cells under oxidative stress.In addition,the Co-SAzyme combined with minocycline achieved remarkable improved functional recovery and neural repairs in the SCI-rat model.

Reversible fluorescent probes for chemical and biological redox process

Oxidation and reduction are important chemical and biological processes. The redox state is related with physical functions and health. Thus, it is meaningful to develop tools for study the redox process.Fluorescence is a powerful method to connecting the microcosm and macrocosm. In this review, we discuss the recent progress of reversible fluorescent probes for chemical and biological redox process according to different active centers.

Experimental investigation on possibility of oxygen enrichment by using gradient magnetic fields

This paper presents a novel method that uses the interception effect of gradient magnetic field on oxygen molecules to realize enrichment.The use of two opposite magnetic poles of two magnets at a certain distance forms a magnetic space having a field intensity gradient near its borders.When air injected into the magnetic space outflows from the magnetic space via its borders,oxygen molecules in the air will experience the interception effect of the gradient magnetic field,but nitrogen molecules will outflow from the magnetic space without hindrance.Thus,continuous oxygen enrichment is realized.The enrichment degree of oxygen reaches 0.65%when the inlet and outlet air flows are 40 mL/min and 20 mL/min,respectively,and the gas temperature is 298 K and the maximal product of magnetic flux density and its gradient is 563 T2/m(the distance between two magnetic poles is 1 mm).When the gas temperature rises to 343 K,the enrichment degree drops to 0.32%;and when the maximal product of magnetic flux density and field intensity gradient drops to 101 T2/m(the distance between two magnetic poles is 4 mm),the enrichment degree drops to 0.23%.The experimental results show that there is an optimal ratio between the inlet air flow and the outlet air flow.Under the experimental conditions in this paper,the value is about 2.0.It is demonstrated that the method presented in this paper can continuously enrich oxygen and has a higher enrich-ment degree than other oxygen-enrichment methods using magnetic separation.

Nanodrugs alleviate acute kidney injury: Manipulate RONS at kidney

Currently,there are no clinical drugs available to treat acute kidney injury(AKI).Given the high prevalence and high mortality rate of AKI,the development of drugs to effectively treat AKI is a huge unmet medical need and a research hotspot.Although existing evidence fully demonstrates that reactive oxygen and nitrogen species(RONS)burst at the AKI site is a major contributor to AKI progression,the heterogeneity,complexity,and unique physiological structure of the kidney make most antioxidant and anti-inflammatory small molecule drugs ineffective because of the lack of kidney targeting and side effects.Recently,nanodrugs with intrinsic kidney targeting through the control of size,shape,and surface properties have opened exciting prospects for the treatment of AKI.Many antioxidant nanodrugs have emerged to address the limitations of current AKI treatments.In this review,we systematically summarized for the first time about the emerging nanodrugs that exploit the pathological and physiological features of the kidney to overcome the limitations of traditional small-molecule drugs to achieve high AKI efficacy.First,we analyzed the pathological structural characteristics of AKI and the main pathological mechanism of AKI:hypoxia,harmful substance accumulation-induced RONS burst at the renal site despite the multifactorial initiation and heterogeneity of AKI.Subsequently,we introduced the strategies used to improve renal targeting and reviewed advances of nanodrugs for AKI:nano-RONS-sacrificial agents,antioxidant nanozymes,and nanocarriers for antioxidants and anti-inflammatory drugs.These nanodrugs have demonstrated excellent therapeutic effects,such as greatly reducing oxidative stress damage,restoring renal function,and low side effects.Finally,we discussed the challenges and future directions for translating nanodrugs into clinical AKI treatment.