Pear genomes display significant genetic diversity and provide novel insights into the fruit quality traits differentiation

The pear(Pyrus spp.)is well known for diverse flavors,textures,and global horticultural importance.However,the genetic diversity responsible for its extensive phenotypic variations remains largely unexplored.Here,we de novo assembled and annotated the genomes of the maternal(PsbM)and paternal(PsbF)lines of the hybrid‘Yuluxiang'pear and constructed the pear pangenome of 1.15 Gb by combining these two genomes with five previously published pear genomes representing cultivated and wild germplasm.Using the constructed pangenome,we identified 21224 gene PAVs(Presence-absence variation)and 1158812 SNPs(Single Nucleotide Polymorphism)in the non-reference genome that were absent in the PsbM reference genome.Compared with SNP markers,PAV-based analysis provides additional insights into the pear population structure.In addition,some genes associated with pear fruit quality traits have differential occurrence frequencies and differential gene expression between Asian and European populations.Moreover,our analysis of the pear pangenome revealed a mutated SNP and an insertion in the promoter region of the gene PsbMGH3.1 potentially enhance sepal shedding in‘Xuehuali'which is vital for pear quality.PsbMGH3.1 may play a role in the IAA pathway,contributing to a distinct low-auxin phenotype observed in plants by heterologously overexpressing this gene.This research helps capture the genetic diversity of pear populations and provides genomic resources for accelerating breeding.

Treatment outcomes and cognitive function following electroconvulsive therapy in patients with severe depression

BACKGROUND Traditional treatments for major depressive disorder(MDD),including medication and therapy,often fail and have undesirable side effects.Electroconvulsive therapy(ECT)uses electrical currents to induce brief seizures in the brain,resulting in rapid and potent antidepressant effects.However,owing to misconceptions and controversies,ECT is not as widely used as it could and often faces stigmatization.AIM To evaluate the efficacy and safety of ECT compared to those of medication and/or therapy in patients with severe MDD.METHODS This prospective cohort study included 220 individuals with severe MDD who were divided into the ECT and non-ECT groups.The patients in the ECT group underwent bilateral ECT three times a wk until they either achieved remission or reached a maximum of 12 sessions.The non-ECT group received medication and/or therapy according to clinical guidelines for MDD.The primary outcome was the variation in the hamilton depression rating scale(HDRS)score from treatment/ECT initiation to week 12.In addition,patients’quality of life,cognitive abilities,and biomarkers were measured throughout the study.RESULTS Although both groups showed significant improvements in their HDRS scores over time,the improvement was more pronounced in the ECT group than in the non-ECT group.Additionally,the ECT group exhibited a more substantial improvement in the quality of life and cognitive function than those of the non-ECT group.Compared with the non-ECT group,the ECT group exhibited evidently lower variations in the brain-derived neurotrophic factor(BDNF)and cytokine interleukin-6(IL-6)levels.The side effects were generally mild and comparable between the two groups.ECT is safer and more potent than medication and/or therapy in mitigating depressive symptoms,enhancing wellbeing,and bolstering cognitive capabilities in individuals with severe MDD.ECT may also affect the levels of BDNF and IL-6,which are indicators of neuroplasticity and inflammation,respectively.CONCLUSION ECT has emerged as a potentially advantageous therapeutic approach for patients with MDD who are unresponsive to alternative treatments.

Predictive value of serum alpha-fetoprotein for tumor regression after preoperative chemotherapy for rectal cancer

BACKGROUND Preoperative therapy is widely used in locally advanced rectal cancer.It can improve local control of rectal cancer.However,there are few indicators that can predict the effect of preoperative chemotherapy accurately.AIM To investigate whether the increase in serumα-fetoprotein(AFP)can predict better efficacy of preoperative chemotherapy.METHODS This was a retrospective study.We analyzed 125 patients admitted between 2017 and 2019 with locally advanced rectal cancer.All patients received six cycles of preoperative chemotherapy(mFOLFOX6 every 2 wk).Serum AFP of 26 patients rose slightly after three or four cycles of chemotherapy,and fell to normal again within 2 mo.The other 99 patients had a normal level of serum AFP during chemotherapy.Patients were divided into two groups(AFP risen and AFP normal).According to postoperative pathology,we compared tumor regression and complete response rate between the two groups.The primary outcome measure was the tumor regression grade(TRG)after chemotherapy.The difference in pathological complete response between the two groups was also investigated.RESULTS There were no tumor progression and distant metastasis in both groups during preoperative chemotherapy.Patients in the AFP risen group achieved better TRG 0/1 than those in the AFP normal group(61.5%vs 39.4%).The increase in AFP was a significant predictor for better tumor regression[χ2=4.144,odds ratio(OR)=2.666,P=0.04].In the AFP risen group,the complete response rate was 30.8%,which was higher than in the AFP normal group(30.8%vs 12.1%,χ2=4.542,OR=3.251,P=0.03).CONCLUSION Patients with a slight increase in serum AFP can achieve better tumor regression during preoperative chemotherapy,and are more likely to achieve pathological complete response.

Circadian disturbance induces erectile dysfunction by impairing endothelial function

In order to explore the impact of circadian disturbance on erectile function,we randomly divided 24 adult male rats into groups of control(light on at 8:00 a.m.and off at 8:00 p.m.),dark/dark(DD;constant dark),light/light(LL;constant light),and shift dark/light(DL;light off at 8:00 a.m.and on at 8:0o p.m.).Four weeks later,erectile function was measured and corpora cavernosa were harvested for analysis.The maximum intracavernous pressure(mlcP)and mCP/mean arterial pressure(MAP)ratio in the DD,LL,and DL groups were significantly lower than that in the control group.The LL and DL groups showed significantly attenuated endothelial nitric oxide synthase(eNOS),while DD,LL,and DL showed reduced neuronal nitric oxide synthase(nNOS)at both mRNA and protein levels.The production of nitric oxide(NO)and cyclic guanosinemonophosphate(cGMP)was inhibited by altered light/dark cycles to varying degrees.Circadian disturbance impaired endothelial function and contributed to erectile dysfunction.For the core circadian elements,mRNA expression of circadian locomotor output cycles kaput(Clock)and brain/muscle aryl-hydrocarbon receptor nuclear translocator-like protein 1(Bmal1)was elevated in the DL group,but their protein expression was not significantly changed.DD,LL,and DL increased period 1(Per1)and Per3 levels,while LL and DL increased PER1 levels.No significant difference was found for Per2levels,and PER2 and PER3 concentrations were not significantly changed.Moreover,LL and DL significantly increased cryptochrome-1(CRY1)and CRY2 at both mRNA and protein levels.The altered light/dark rat model showed that circadian disturbance contributed to erectile dysfunction probably by impairing endothelial function.Meanwhile,the core circadian elements were detected in the corpora cavernosa,but these were disrupted.However,which circadian element regulates erectile function and how it works need further analysis.

Graphene enhances artemisinin production in the traditional medicinal plant Artemisia annua via dynamic physiological processes and miRNA regulation

We investigated the effects of graphene on the model herb Artemisia annua,which is renowned for produc-ing artemisinin,a widely used pharmacological compound.Seedling growth and biomass were promoted when A.annua was cultivated with low concentrations of graphene,an effect which was attributed to a 1.4-fold increase in nitrogen uptake,a 15%–22%increase in chlorophyllfluorescence,and greater abun-dance of carbon cycling–related bacteria.Exposure to 10 or 20 mg/L graphene resulted in a�60%increase in H2O2,and graphene could act as a catalyst accelerator,leading to a 9-fold increase in catalase(CAT)ac-tivity in vitro and thereby maintaining reactive oxygen species(ROS)homeostasis.Importantly,graphene exposure led to an 80%increase in the density of glandular secreting trichomes(GSTs),in which artemisinin is biosynthesized and stored.This contributed to a 5%increase in artemisinin content inmature leaves.Inter-estingly,expression of miR828 was reduced by both graphene and H2O2 treatments,resulting in induction of its target gene AaMYB17,a positive regulator of GST initiation.Subsequent molecular and genetic assays showed that graphene-induced H2O2 inhibits micro-RNA(miRNA)biogenesis through Dicers and regulates the miR828–AaMYB17 module,thus affecting GST density.Our results suggest that graphene may contribute to yield improvement in A.annua via dynamic physiological processes together with miRNA regulation,and it may thus represent a new cultivation strategy for increasing yield capacity through nanobiotechnology.

ASFV多表位融合基因MeP72基因的克隆、表达及其间接ELISA检测方法建立

[目的]建立以重组多表位融合蛋白reMeP72为包被抗原的ASFV间接ELISA检测方法。[方法]预测分析ASFV结构蛋白P72的优势抗原表位,串连优势抗原表位并优化稀有密码子以合成多表位融合抗原基因MeP72。在毕赤酵母表达系统中诱导表达,分析重组融合蛋白的反应原性。用reMeP72做包被抗原,建立ASFV的ELISA间接检测方法。[结果]成功构建了402bp的MeP72基因片段。SDS-PAGE和WesternBlotting分析该蛋白在14kDa有条带,证明其反应原性良好。经ELISA反应条件优化,建立的ELISA方法与猪的其他病原的阳性血清不发生交叉反应,且可检测到稀释倍数为1∶512ASFV阳性血清,证明其特异性和敏感性良好。[结论]建立了抗原包被浓度为15μg/mL,一抗、二抗稀释倍数分别为1∶200、1∶5000倍的特异性和敏感性良好的reMeP72-ELISA检测方法。

Numerical simulation for pulsed laser-gas tungsten arc hybrid welding of magnesium alloy

Based on the extended application of COMSOL multiphysics, a novel dual heat source model for pulsed laser-gas tungsten arc （GTA） hybrid welding was established. This model successfully solved the problem of simulation inaccuracy caused by energy superposition effect between laser and arc due to their different physical characteristics. Numerical simulation for pulsed laser-GTA hybrid welding of magnesium alloy process was conducted, and the simulation indicated good agree- ments with the measured thermal cycle curve and the shape of weld beads. Effects of pulse laser parameters （laser-excited current, pulse duration, and pulse frequency） on the temperature field and weld pool morphology were investigated. The experimental and simulation results suggest that when the laser pulse energy keeps constant, welding efficiency of the hybrid heat source is increased by increasing laser current or decreasing pulse duration due to the increased ratio of the weld bead depth to width. With large laser currents, severe spatters tend to occur. For optimized welding process, the laser current should be controlled in the range of 150-175 A, the pulse duration should be longer than 1 ms, and the pulse frequency should be equal to or slightly greater than 20 Hz.

OPTIMAL RESERVE PRICE IN STATIC AND DYNAMIC SPONSORED SEARCH AUCTIONS

Sponsored search advertising is a significant revenue source for search engines. To ameliorate revenues, search engines often set fixed or variable reserve price to in influence advertisers＇ bidding. This paper studies the optimal reserve price for a generalized second-price auction （GSP） under both static and dynamic settings. We show that if advertisers＇ per-click value has an increasing generalized failure rate, the search engine＇s revenue rate is quasi-concave and hence there exists an optimal reserve price under both settings. Different from a static GSP auction where the optimal reserve price is proved to be constant, in a dynamic setting the optimal reserve price is dependent on not only advertisers＇ per-click values, but also the number of ad links sold. A search engine should gradually raise reserve price as more qualified advertisers arrive, and maintain the same threshold after all first-page positions are occupied.

Bioremediation of highly contaminated oilfield soil： Bioaugmentation for enhancing aromatic compounds removal

This study evaluated the effectiveness of different amendments--including a commercial NPK fertilizer, a humic substance （HS）, an organic industrial waste （NovoGro）, and a yeast-bacteria consortium--in the remediation of highly contaminated （up to 6% of total petroleum hydrocarbons） oilfield soils. The concentrations of hydrocarbon, soil toxicity, physicochemical properties of the soil, microbial population numbers, enzyme activities and microbial community structures were examined during the 90-d incubation. The results showed that the greatest degradation of total petroleum hydro- carbons （TPH） was observed with the biostimulation using mixture of NPK, HS and NovoGro, a treatment scheme that enhanced both dehydrogenase and lipase activities in soil. Introduction of exogenous hydrocarbon-degrading bacteria （in addition to biostimulation with NPK, HS and NovoGro） had negligible effect on the removal of TPH, which was likely due to the competition between exogenous and autochthonous microorganisms. None- theless, the addition of exogenous yeast-bacteria consor- tium significantly enhanced the removal of the aromatic fraction of the petroleum hydrocarbons, thus detoxifying the soil. The effect of bioaugmentation on the removal of more recalcitrant petroleum hydrocarbon fraction was likely due to the synergistic effect of bacteria and fungi.