Ethylene accelerates maize leaf senescence in response to nitrogen deficiency by regulating chlorophyll metabolism and autophagy

Leaf senescence is an orderly and highly coordinated process,and finely regulated by ethylene and nitrogen(N),ultimately affecting grain yield and nitrogen-use efficiency(NUE).However,the underlying regulatory mechanisms on the crosstalk between ethylene-and N-regulated leaf senescence remain a mystery in maize.In this study,ethylene biosynthesis gene ZmACS7 overexpressing(OE-ZmACS7)plants were used to study the role of ethylene regulating leaf senescence in response to N deficiency,and they exhibited the premature leaf senescence accompanied by increased ethylene release,decreased chlorophyll content and F_v/F_m ratio,and accelerated chloroplast degradation.Then,we investigated the dynamics changes of transcriptome reprogramming underlying ethylene-accelerated leaf senescence in response to N deficiency.The differentially expressed genes(DEGs)involved in chlorophyll biosynthesis were significantly down-regulated,while DEGs involved in chlorophyll degradation and autophagy processes were significantly up-regulated,especially in OE-ZmACS7 plants in response to N deficiency.A gene regulatory network(GRN)was predicted during ethylene-accelerated leaf senescence in response to N deficiency.Three transcription factors(TFs)ZmHSF4,Zmb HLH106,and ZmEREB147 were identified as the key regulatory genes,which targeted chlorophyll biosynthesis gene ZmLES22,chlorophyll degradation gene ZmNYC1,and autophagy-related gene ZmATG5,respectively.Furthermore,ethylene signaling key genes might be located upstream of these TFs,generating the signaling cascade networks during ethylene-accelerated leaf senescence in response to N deficiency.Collectively,these findings improve our molecular knowledge of ethylene-accelerated maize leaf senescence in response to N deficiency,which is promising to improve NUE by manipulating the progress of leaf senescence in maize.

Ultrasound-Guided Transmuscular Quadratus Lumbar Block Reduces Opioid Consumption after Laparoscopic Partial Nephrectomy

Objectives Transmuscular quadratus lumborum block(TQLB)may provide postoperative analgesia in patients undergoing intraperitoneal surgeries.The purpose of this study was to examine the potential efficacy of TQLB among patients undergoing retroperitoneal procedures,such as the laparoscopic partial nephrectomy(LPN).Methods This prospective,randomized,controlled study was conducted from August 2017 to November 2018 at Peking Union Medical College Hospital(Beijing,China).Patients who were scheduled for a LPN,aged 18・70 years old with an ASA physical status score of I-II were randomly assigned to receive either TQLB with 0.6 ml/kg of 0.5%ropivacaine plus general anesthesia(TQLB group)or general anesthesia alone(control group).Patient-controlled intravenous analgesia with morphine was initiated immediately upon surgery completion.The primary outcome was the cumulative consumption of morphine within 8 h after surgery.The secondary outcome included postoperative consump廿ons of morphine at other time points,pain score at rest and during activity,postoperative nausa and vomitting(PONV),and recovery related parameters.Results Totally 30 patients per group were recruited in the study.The 8 h consumption of morphine was lower in theTQLB group than in the control group(median,0.023 mg/kg vs.0.068 mg/kg,U=207.5,P<0.001).No significant differences were observed in postoperative pain scores between the two groups.Patients in the TQLB group had fewer episodes of PONV(20%vs.47%,χ2=4.&P=0.028)in the first 24 h after surgery and higher scores for quality of recovery(mean,13&6 vs.131.9,t=-2.164,P=0.035)120 h after surgery than the controls.Conclusions TQLB resulted in an opioid-sparing effect during the early postoperative period following LPN,as well as a lower incidence of PONV and improved quality of recovery.

Exogenous application of glycine betaine improved water use efficiency in winter wheat(Triticum aestivum L.) via modulating photosynthetic efficiency and antioxidative capacity under conventional and limited irrigation conditions

Improving water use efficiency(WUE)is an important subject in agricultural irrigation for alleviating the scarcity of water resources in semiarid regions of the North China Plain.Moreover,glycine betaine(GB)is one of the most effective compatible solutes synthesized naturally in plants for enhancing stress tolerance under abiotic stress,but little information is available on the involvement of GB in regulating crop WUE under field conditions.This study was conducted to explore the role of exogenously applied GB in improving WUE and plant physiological and biochemical responses inwinterwheat subjected to conventional or limited irrigation during the 2015–2016 and 2016–2017 growing seasons.Exogenous application of GB significantly enhanced antioxidant enzyme activities and reduced the accumulation ofmalondialdehyde and hydrogen peroxide under limited irrigation conditions.Furthermore,GB-treated plantsmaintained higher leaf relative water content andmembrane stability,which led to higher chlorophyll content and gas exchange attributes for better intrinsic and instantaneouswater use efficiencies compared to control plants under limited irrigation conditions.GB-treated plants had higher indole-acetic acid and zeatin riboside levels but lower ABA levels compared to control plants under conventional and limited irrigation conditions.Additionally,GB enhanced the grain filling rate and duration,grain number per spike,and final grainweight,which resulted in higher grain yield compared to the control.Interestingly,GB significantly improved the integrative and photosynthetic WUE under conventional and limited irrigation conditions,although GB treatment did not markedly affect total water consumption.These results suggest the involvement of GB in improving WUEs in winter wheat by modulating hormonal balance,membrane stability,photosynthetic performance and antioxidant systems to maintain higher grain yield under conventional and limited irrigation conditions.

Brassinosteroids modulate nitrogen physiological response and promote nitrogen uptake in maize(Zea mays L.)

Brassinosteroids(BRs)are steroid hormones that function in plant growth and development and response to environmental stresses and nutrient supplies.However,few studies have investigated the effect of BRs in modulating the physiological response to nitrogen(N)supply in maize.In the present study,BR signalingdeficient mutant zmbri1-RNAi lines and exogenous application of 2,4-epibrassinolide(e BL)were used to study the role of BRs in the regulation of physiological response in maize seedlings supplied with N.Exogenous application of e BL increased primary root length and plant biomass,but zmbri1 plants showed shorter primary roots and less plant biomass than wild-type plants under low N(LN)and normal N(NN)conditions.LN induced the expression of the BR signaling-associated genes Zm DWF4,Zm CPD,Zm DET2,and Zm BZR1 and the production of longer primary roots than NN.Knockdown of Zm BRI1 weakened the biological effects of LN-induced primary root elongation.e BL treatment increased N accumulation in shoots and roots of maize seedlings exposed to LN or NN treatment.Correspondingly,zmbri1 plants showed lower N accumulation in shoots and roots than wild-type plants.Along with reduced N accumulation,zmbri1 plants showed lower NO3-fluxes and^(15)NO_(3)^(-)uptake.The expression of nitrate transporter(NRT)genes(Zm NPF6.4,Zm NPF6.6,Zm NRT2.1,Zm NRT2.2)was lower in zmbri1 than in wild-type roots,but e BL treatments up-regulated the transcript expression of NRT genes.Thus,BRs modulated N physiological response and regulated the transcript expression of NRT genes to promote N uptake in maize.

Value of Preoperative Neutrophil-to-Lymphocyte Ratio in Predicting Prognosis of Surgically Resectable Urinary Cancers: Systematic Review and Meta-Analysis

Objective Accumulated evidence has suggested that there is a close association between preoperative neutrophilto-lymphocyte ratio(NLR)and prognosis of various malignant tumors.However,the relationship between NLR and surgically resectable urinary cancers remains contradictory.Therefore,we performed this systematic review and meta-analysis to explore whether preoperative NLR could predict the prognosis of surgically resectable urinary cancers.Methods After searching the Embase,PubMed/MEDLINE and Cochrane databases and screening the articles,we finally included 25 studies involving 15950 patients.Hazard ratios(HRs)and their 95%confidence intervals(CIs)were extracted to assess the association between preoperative NLR and the overall survival(OS)and cancerspecific survival(CSS)of surgically resectable urinary cancers.Results The pooled results revealed that an elevated preoperative NLR could predict a worse OS(HR=1.40,95%CI:1.26–1.54,P<0.001)and CSS(HR=1.43,95%CI:1.27–1.59,P<0.001)in urinary cancers.In addition,our analyses also suggested that high preoperative NLR was associated with worse prognosis in renal cell carcinoma(OS:HR=2.06,95%CI:1.54–2.76,P=0.131;CSS:HR=2.46,95%CI:1.46–4.16,P=0.178),upper tract urothelial carcinoma(OS:HR=1.91,95%CI:1.50–2.42,P=0.616;CSS:HR=1.84,95%CI:1.41–2.39,P=0.001),bladder cancer(OS:HR=1.09,95%CI:1.02–1.17,P<0.001;CSS:HR=1.05,95%CI:1.01–1.09,P=0.163)and prostate cancer(OS:HR=1.69,95%CI:1.19–2.41,P=0.714).Regardless of the participants’race or the cutoff value of the preoperative NLR,the results remained valid.Conclusion Elevated preoperative NLR could predict a worse prognosis in surgically resectable urinary cancers,namely,renal cell carcinoma,bladder cancer,prostate cancer and upper tract urothelial carcinoma.

Evaluation of the chemical profile from four germplasms sources of Pruni Semen using UHPLC-LTQ-Orbitrap-MS and multivariate analyses

Pruni Semen,the seed of several unique Prunus plants,is a traditional purgative herbal material.To determine the authentic sources of Pruni Semen,46 samples from four species were collected and analyzed.Ten compounds including multiflorin A(Mul A),a notable purative compound,were isolated and identified by chemical separation and nuclear magnetic resonance spectroscopy.Seventy-six communal components were identified by ultra-high performance liquid chromatography with linear ion trap-quadrupole Orbitrap mass spectrometry,and acetyl flavonoid glycosides were recognized as characteristic constituents.The flavonoids were distributed in the seed coat and cyanogenic glycosides in the kernel.Based on this,methods for identifying Pruni Semen from different sources were established using chemical fingerprinting,quantitative analysis of the eight principal compounds,hierarchical cluster analysis,principal component analysis,and orthogonal partial least squares discriminant analysis.The results showed that the samples were divided into two categories:one is the small seeds from Prunus humilis(Ph)and Prunus japonica(Pj),and the other is the big seeds from Prunus pedunculata(Pp)and Prunus triloba(Pt).The average content of Mul A was 3.02,6.93,0.40,and 0.29 mg/g,while the average content of amygdalin was 18.5,17.7,31.5,and 30.9 mg/g in Ph,Pj,Pp,and Pt,respectively.All the above information suggests that small seeds might be superior sources of Pruni Semen.This is the first comprehensive report on the identification of chemical components in Pruni Semen from different species.

Preliminary Application of WCX Magnetic Bead-Based Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry in Analyzing the Urine of Renal Clear Cell Carcinoma

Objective To evaluate the application of weak cation exchange (WCX) magnetic bead-based Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in detecting differentially expressed proteins in the urine of renal clear cell carcinoma (RCCC) and its value in the early diagnosis of RCCC.Methods Eleven newly diagnosed patients (10 males and 1 female, aged 46-78, mean 63 years) of renal clear cell carcinoma by biopsy and 10 healthy volunteers (all males, aged 25-32, mean 29.7 years) were enrolled in this study. Urine samples of the RCCC patients and healthy controls were collected in the morning.Weak cation exchange (WCX) bead-based MALDI-TOF MS technique was applied in detecting differential protein peaks in the urine of RCCC. ClinProTools2.2 software was utilized to determine the characteristic proteins in the urine of RCCC patients for the predictive model of RCCC.Results The technique identified 160 protein peaks in the urine that were different between RCCC patients and health controls; and among them, there was one peak (molecular weight of 2221.71 Da) with statistical significance (P=0.0304). With genetic algorithms and the support vector machine, we screened out 13 characteristic protein peaks for the predictive model.Conclusions The application of WCX magnetic bead-based MALDI-TOF MS in detecting differentiallyexpressed proteins in urine may have potential value for the early diagnosis of RCCC.

A new model for Doppler shift of C-band echoes backscattered from sea surface

Within the framework of the two-scale scattering model,the Doppler shift of C-band radar return signals from the nonlinear sea surface are numerically evaluated.As an analytical approximation method,the Bragg resonance scattering method cannot accurately describe the backscattering field from sea surface.Therefore,in the twoscale scattering model,more accurate scattering coefficient(the normalized radar cross section,NRCS)evaluated by the C-band dual-polarized(HH/VV)empirical geophysical model function(CSAR model)is employed to replace the traditional Bragg NRCS to weight the Doppler shift.The numerical results indicate that there are obvious differences between the Doppler shift weighted by the CSAR NRCS and that weighted by the traditional Bragg NRCS.The hydrodynamic modulation of the large-scale waves is one of the important factors that affect the difference between the Doppler shift predicted in upwind and downwind directions.If the relaxation rate in the hydrodynamic modulation is set to be the angular frequency of the dominant water waves,the Doppler shift predicted by the numerical method can fit the results of the empirical model(C-band empirical geophysical model function,CDOP)well at moderate wind speed.Under low wind condition,the comparison shows that the empirical CDOP model appears to overestimate the Doppler shift.In order to facilitate the application,at the end of this paper a semi-empirical CSAR-DOP model,which is a polynomial fitting formula,is developed for evaluating the Doppler shift of C-band signals from time varying sea surface.

Effects of AlCoCrFeNiTi high-entropy alloy on microstructure and mechanical properties of pure aluminum

A new kind of AlCoCrFeNiTi high-entropy alloy(HEA)as a grain refiner was prepared by vacuum arc melting.In this work,the effects of HEA(1.0 wt.%,2.0 wt.%and 3.0 wt.%)on the microstructure and mechanical properties of pure aluminum were studied.The microstructure was characterized and examined by scanning electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD),electron probe micro-analyzer(EPMA)and transmission electron microscopy(TEM)to indicate the refining abilities and mechanism of HEA on pure aluminum.Results show that the addition of HEA refined both the macrostructure and microstructure of pure aluminum.When 1.0 wt.%HEA was added,most coarse columnar grains were refined into equiaxed crystals,and as the amount of HEA increased to 2.0 wt.%and3.0 wt.%,aluminum grains were further refined,and the grain boundaries were nearly indistinguishable.Moreover,the morphology ofα-Al transformed from coarse columnar crystals to equiaxed grains,and the mean size ofα-Al grains decreased from 374μm to 27μm.The Al3Ti,Al3Ni,and nano-phase precipitated from the aluminum alloy with HEA in the solidification.The typical rod-like nano-phases distributed interdendritic regions ofα-Al.The average length of nano-phases is 2568 nm,4372 nm,and 6907 nm and the average diameter is 112 nm,103 nm,and 92 nm when 1.0 wt.%,2.0 wt.%and 3.0 wt.%HEA were added to the pure aluminum,respectively.The ultimate tensile strength(UTS)and yield strength(YS)were improved in all samples,whereas the elongation(El)was decreased with increasing HEA concentration.When 3.0 wt.%HEA was added into the aluminum melt,the UTS was improved by 145.2%from62 MPa to 152 MPa,the YS was increased by 173.8%from 42 MPa to 115 MPa,and the El was decreased by 33.3%from 39%to 26%.

High resolution non-invasive intraocular pressure monitoring by use of graphene woven fabrics on contact lens

Monitoring intracorporal pressures are important for health care and diagnosis.In this work,a contact lens tonometer employing graphene woven fabrics(GWFs),which indicate great sensibility of resistance to strain,flexibility,stretchability,transparency,and biocompatibility,is proposed for real-time monitoring intraocular pressure(IOP)with high resolution.The mechanical properties of the device during the deformation were analyzed,and the sensitivity of the fabricated device was tested on a mimic human eyeball.In vitro experiments on porcine eyes were executed to test the effectiveness of the device.The change rate of resistance under different IOP was tested.Also,the relationship between the current changes and IOP variation when keeping the voltage constant for different devices was obtained.The contact lens tonometers with GWFs as high-resolution sensing element have shown a promising prospective to realize the low-cost disposable sensing contact lens with lower power.

Dragon’s Blood Protect Rat Blood-Brain Barrier Dysfunction Induced by Simulated Microgravity Effect

Dragon’s blood(DB)has shown a protective effect on neurological diseases.Microgravity(MG)or simulated MG(SMG)can induce blood-brain barrier(BBB)dysfunction,which is a characteristic feature of neurological disorders.This study’s purpose was to evaluate the effect of DB on SMG-induced BBB dysfunction and explore its signaling pathway.Both DB and vitamin C(Vc)were administered orally for tail-suspended rats within 3 weeks.DB and Vc solutions were added to human brain microvascular endothelial cells(HCMEC/D3)cells,which were then exposed to SMG for 24 h.The protective effect of DB was assessed by hematoxylin and eosin and Nissl staining,ultrastructure observation,and permeability in rats.Cell apoptosis and the distribution of tight junction(TJ)and adherens junction(AJ)proteins and filamentous actin(F-actin)were examined in HCMEC/D3.The oxidative stress and inflammation,and TJ and AJ protein expressions were determined in rat brain and HCMEC/D3.The focal adhesion kinase(FAK)signaling pathway proteins were determined.DB protected SMG-induced rat BBB disruption by improving neuronal apoptosis,repairing widened intercellular space,and decreasing BBB permeability.DB effectively relieved SMG-induced HCMEC/D3 damage by inhibiting cell apoptosis and restoring F-actin spindle distribution.High doses of DB upregulated TJ and AJ protein expressions and decreased oxidative stress and proinflammatory cytokine levels in rat brain and HCMEC/D3.DB enhanced the expressions of FAK signal transduction proteins and F-actin/globular actin(G-actin)ratio in rat brain and HCMEC/D3,suggesting that DB promotes actin cytoskeleton polymerization,benefits the endothelial cell-cell and cell-extracellular matrix adhesion,and,in consequence,contributes to BBB integrity.