Design of pH-responsive antimicrobial peptide melittin analog-camptothecin conjugates for tumor therapy

Melittin,a classical antimicrobial peptide,is a highly potent antitumor agent.However,its significant toxicity seriously hampers its application in tumor therapy.In this study,we developed novel melittin analogs with pH-responsive,cell-penetrating and membranelytic activities by replacing arginine and lysine with histidine.After conjugation with camptothecin(CPT),CPT-AAM-1 and CPT-AAM-2 were capable of killing tumor cells by releasing CPT at low concentrations and disrupting cell membranes at high concentrations under acidic conditions.Notably,we found that the C-terminus of the melittin analogs was more suitable for drug conjugation than the N-terminus.CPT-AAM-1 significantly suppressed melanoma growth in vivo with relatively low toxicity.Collectively,the present study demonstrates that the development of antitumor drugs based on pH-responsive antimicrobial peptide-drug conjugates is a promising strategy.

Two-Layer Information Granulation:Mapping-Equivalence Neighborhood Rough Set and Its Attribute Reduction

Attribute reduction,as one of the essential applications of the rough set,has attracted extensive attention from scholars.Information granulation is a key step of attribute reduction,and its efficiency has a significant impact on the overall efficiency of attribute reduction.The information granulation of the existing neighborhood rough set models is usually a single layer,and the construction of each information granule needs to search all the samples in the universe,which is inefficient.To fill such gap,a new neighborhood rough set model is proposed,which aims to improve the efficiency of attribute reduction by means of two-layer information granulation.The first layer of information granulation constructs a mapping-equivalence relation that divides the universe into multiple mutually independent mapping-equivalence classes.The second layer of information granulation views each mapping-equivalence class as a sub-universe and then performs neighborhood informa-tion granulation.A model named mapping-equivalence neighborhood rough set model is derived from the strategy of two-layer information granulation.Experimental results show that compared with other neighborhood rough set models,this model can effectively improve the efficiency of attribute reduction and reduce the uncertainty of the system.The strategy provides a new thinking for the exploration of neighborhood rough set models and the study of attribute reduction acceleration problems.

Observation and analysis of morphology abnormalities in development of Oryzias melastigma embryos

Fish embryos are widely used as models in toxicology,drug development,and human disease research because of their high sensitivity,observability,and operability,providing the basis for an in-depth understanding of the embryogenesis.Increasing studies have indicated that birth defects are hereditary.In this study,we used Oryzias melastigma as a model to conduct a study of 185-day embryogenesis and observed self-induced non-pathological abnormal embryogenesis.O.melastigma experienced pre-puberty stage,adolescence stage,and senescence stage,and individuals produced up to 102 eggs per day.However,the fecundity was markedly reduced during the senescent stage.During the active egg and blastodisc stages,pseudo-fertilization and pseudo-blastocysts were observed.During cleavage at the 4-to 32-cell stages,we observed blastomeres separation or dislocation.Excessively separated blastomeres formed double blastoderms,eventually resulting in conjoined twins.During the blastula stage,we observed abnormally increased cell volume,narrowed and elongated blastocysts,and abnormally coated blastoderms.At the organogenesis stage,we observed abnormal numbers of Kupff er’s vesicles and conjoined twins.Abnormality in the location and number of oil droplets were observed in various development stages.Abnormal development was more commonly observed in fertilized eggs produced by broodstock in pre-puberty or senescence stages,which is probably related to the age of fish and the egg quality.This study can provide the materials for comparative analysis in toxicological and molecular studies of O.melastigma,and may provide evidence for other economic fish that produce sticky eggs.

Laboratory simulation of dissolved oxygen reduction and ammonia nitrogen generation in the decay stage of harmful algae bloom

To evaluate how the decay of bloom-forming algae affect the coastal dissolved oxygen,a laboratory simulation was conducted in terms of three typical harmful algae,Alexandrium catenella,Prorocentrum donghaiense,and Skeletonema costatum.Algae of same biomass(55μg/mL)were conducted in lightproof columns,and the cell density,dissolved oxygen(DO),and ammonia nitrogen of different layers were monitored at certain time series.Results show that the decomposition of algae significantly decreased the DO,and increased the ammonia nitrogen in all layers;and significant deference between different species was observed.The A.catenella treatment showed the lowest DO(average concentration of 3.4 mg/L)and the highest ammonia nitrogen(average concentration of 0.98 mg/L)at the end of test,followed by P.donghaiense;and the S.costatum showed relatively high DO and low ammonia nitrogen due to slow decay rate.Results indicate that decomposition of harmful bloom algae,especially dinoflagellate,would cause significantly DO depletion and toxic ammonia nitrogen increase,which will detrimentally affect both pelagic and benthic ecosystem.

Reduced salinity interacts with ultraviolet radiation to alter photosystem Ⅱ function in diatom Skeletonema costatum

To investigate the effect of reduced salinity on diatoms’ capacity to cope with changing ultraviolet radiation(U VR) and photosynthetically active radiation(PAR),Skeletonema costatum was grown in a range of salinity(15,25,and 35).The photo system Ⅱ(PSⅡ) function was analyzed by increasing PAR and UVR to mimic a mixing event in turbulent waters.The re sults show that high UVR exposure significantly reduced PSII activity,especially in cells grown at low salinity.UVR,but not salinity,stimulated the ’removal’ rate of PSII protein PsbA.Salinity alone,in the range of 15 to 35,did not regulate PSⅡ acceptor region;however,the low salinity+UVR treatment decreased the energy flux for electron transport per PSⅡ reaction center in S.costatum.It showed that low salinity exacerbated the damaging effect of UVR on PSⅡ function in S.costatum by suppressing Psb A protein synthe sis and modifying the photochemistry of PSⅡ.Although higher catalase(CAT) activity and NPQs were induced,they were unable to prevent the combined damage effect of low salinity+UVR.Our findings indicate that reduced salinity and increased UVR potentially affect the abundance and distribution of S.costatum with the escalation of climate disturbances.

Conjugation with Acridines Turns Nuclear Localization Sequence into Highly Active Antimicrobial Peptide

The emergence of multidrug-resistant bacteria creates an urgent need for alternative antibiotics with new mechanisms of action. In this study, we synthesized a novel type of antimicrobial agent, Ac r_3-NLS, by conjugating hydrophobic acridines to the N-terminus of a nuclear localization sequence(NLS), a short cationic peptide. To further improve the antimicrobial activity of our agent, dimeric(Acr_3-NLS)_2 was simultaneously synthesized by joining two monomeric Acr_3-NLS together via a disulfide linker. Our results show that Acr_3-NLS and especially(Acr_3-NLS)_2 display signifi cant antimicrobial activity against gramnegative and gram-positive bacteria compared to that of the NLS. Subsequently, the results derived from the study on the mechanism of action demonstrate that Acr_3-NLS and(Acr_3-NLS)_2 can kill bacteria by membrane disruption and DNA binding. The double targets—cell membrane and intracellular DNA—will reduce the risk of bacteria developing resistance to Acr_3-NLS and(Acr_3-NLS)_2. Overall, this study provides a novel strategy to design highly eff ective antimicrobial agents with a dual mode of action for infection treatment.

Proteomic Analysis of Chrysanthemum Lateral Buds after Removing Apical Dominance Based on Label-Free Technology

Studying the genetic basis and regulatory mechanism of chrysanthemum lateral bud outgrowth is of great significance for reduction the production cost of cut chrysanthemum.To clarify the molecular basis of lateral bud elongation after removal of apical dominance in chrysanthemum,label-free quantification analysis was used to analyze the proteome changes after apical bud removal.Quantitative real-time PCR(qPCR)was used to analyze the changes in the expression of three plant hormone-related genes.A total of 440 differentially expressed proteins were successfully identified at three time points during the lateral bud elongation.The number of differentially expressed proteins in the three stages(24 h/0 h,48 h/0 h,48 h/24 h)were 219,332,and 97,respectively.The difference in expressed proteins in the three comparison stages mainly involves RNA processing and modification;translation,ribosomal structure and biogenesis;Posttranslational modification,protein turnover,and chaperones.Path analysis showed that there was various physiological activities in the process of lateral bud dormancy breaking and elongation,which involved energy metabolism,biosynthesis,signal transduction and stress response in the growth process of lateral buds.qPCR indicated that the expression of cytokinin synthesis related gene was significantly increased after the removal of apical dominance,while the expression of strigolactones synthesis related gene experiences a dramatic fall to promote the development of the lateral buds.However,there was a drop before a slight increase in the expression of the auxin synthesis related gene,which was mainly due to the removal of apical dominance that led to the loss of indoleacetic acid in the main stem.However,with formation of the new apical source,indoleacetic acid can be released again.

基于Flexsim的L服装公司配送流程仿真优化研究

为提高L服装公司配送效率和顾客满意度,对其配送中心作业流程进行实地调研,基于实际配送流程和相关数据,运用Flexsim软件建立仿真模型,对比分析了正常状态与订单剧增状态下配送数据,结果表明制约整个配送流程的核心作业环节为分拣。进而确定了订单剧增时缩短作业时间至正常水平和降低堵塞率至0的优化目标,通过多次比较分析,提出2种解决方案:引进智能分拣设备、调整库存容量。最终完成对L服装公司配送流程的改善,可为业界内其它企业配送流程的优化提供借鉴。

Circulating biomarker-and magnetic resonance-based nomogram predicting long-term outcomes in dilated cardiomyopathy

Background:Dilated cardiomyopathy(DCM)has a high mortality rate and is the most common indication for heart transplantation.Our study sought to develop a multiparametric nomogram to assess individualized all-cause mortality or heart transplantation(ACM/HTx)risk in DCM patients.Methods:The present study is a retrospective cohort study.The demographic,clinical,blood test,and cardiac magnetic resonance imaging(CMRI)data of DCM patients in the tertiary center(Fuwai Hospital)were collected.The primary endpoint was ACM/HTx.The least absolute shrinkage and selection operator(LASSO)Cox regression model was applied for variable selection.Multivariable Cox regression was used to develop a nomogram.The concordance index(C-index),area under the receiver operating characteristic curve(AUC),calibration curve,and decision curve analysis(DCA)were used to evaluate the performance of the nomogram.Results:A total of 218 patients were included in the present study.They were randomly divided into a training cohort and a validation cohort.The nomogram was established based on eight variables,including mid-wall late gadolinium enhancement,systolic blood pressure,diastolic blood pressure,left ventricular ejection fraction,left ventricular end-diastolic diameter,left ventricular end-diastolic volume index,free triiodothyronine,and N-terminal pro-B type natriuretic peptide.The AUCs regarding 1-year,3-year,and 5-year ACM/HTx events were 0.859,0.831,and 0.840 in the training cohort and 0.770,0.789,and 0.819 in the validation cohort,respectively.The calibration curve and DCA showed good accuracy and clinical utility of the nomogram.Conclusions:We established and validated a circulating biomarker-and CMRI-based nomogram that could provide a personalized prediction of ACM/HTx for DCM patients,which might help risk stratification and decision-making in clinical practice.

Dual single-atom Ce-Ti/MnO_(2)catalyst enhances low-temperature NH_(3)-SCR performance with high H_(2)O and SO_(2)resistance

Mn-based catalysts have exhibited promising performance in low-temperature selective catalytic reduction of NOx with NH_(3)(NH_(3)-SCR).However,challenges such as H_(2)O-or SO_(2)-induced poisoning to these catalysts still remain.Herein,we report an efficient strategy to prepare the dual single-atom Ce-Ti/MnO_(2)catalyst via ball-milling and calcination processes to address these issues.Ce-Ti/MnO_(2)showed better catalytic performance with a higher NO conversion and enhanced H_(2)O-and SO_(2)-resistance at a lowtemperature window(100−150°C)than the MnO_(2),single-atom Ce/MnO_(2),and Ti/MnO_(2)catalysts.The in situ infrared Fourier transform spectroscopy analysis confirmed there is no competitive adsorption between NOx and H_(2)O over the Ce-Ti/MnO_(2)catalyst.The calculation results showed that the synergistic interaction of the neighboring Ce-Ti dual atoms as sacrificial sites weakens the ability of the active Mn sites for binding SO_(2)and H_(2)O but enhances their binding to NH_(3).The insight obtained in this work deepens the understanding of catalysis for NH_(3)-SCR.The synthesis strategy developed in this work is easily scaled up to commercialization and applicable to preparing other MnO_(2)-based single-atom catalysts.

Reduction of low-grade manganese oxide ore by biomass roasting

The reduction process of manganese dioxide in low-grade manganese ore by biomass roasting was investigated.The calcine of manganese oxide ore was further leached by sulphuric acid, the manganese in ore can be converted into manganese sulfate.Effects of the mass ratio of manganese ore to sawdust, roasting temperature and time, leaching temperature and time, leaching agent concentration and liquid-solid ratio were studied.97.71% of manganese recovery can be achieved under the optimal conditions：the mass ratio of manganese ore to sawdust of 5：1, roasting temperature at 500℃ for 40 min, leaching temperature at 60℃ for 40 min, sulphuric acid concentration of 1 mol/L and liquid-solid ratio of 10：1.Other types of low-grade manganese ore like Guilin ore, Nanning ore and Gongcheng ore were tested and the same results were obtained.

Sialic acid-engineered mesoporous polydopamine nanoparticles loaded with SPIO and Fe3+as a novel theranostic agent for T1/T2 dual-mode MRI-guided combined chemo-photothermal treatment of hepatic cancer

diagnostic and therapeutic capability are highly needed for the treatment of hepatic cancer.Herein,we aimed to develop a novel mesoporous polydopamine(MPDA)-based theranostic agent for T1/T2 dual magnetic resonance imaging(MRI)-guided cancer chemo-photothermal therapy.Superparamagnetic iron oxide(SPIO)-loaded MPDA NPs(MPDA@SPIO)was firstly prepared,followed by modifying with a targeted molecule of sialic acid(SA)and chelating with Fe^(3+)(SA-MPDA@SPIO/Fe^(3+) NPs).After that,doxorubicin(DOX)-loaded SA-MPDA@SPIO/Fe^(3+) NPs(SA-MPDA@SPIO/DOX/Fe^(3+))was prepared for tumor theranostics.The prepared SAPEG-MPDA@SPIO/Fe^(3+) NPs were water-dispersible and biocompatible as evidenced by MTT assay.In vitro photothermal and relaxivity property suggested that the novel theranostic agent possessed excellent photothermal conversion capability and photostability,with relaxivity of being r1=4.29 mM1s1 and r2=105.53 mM1s1,respectively.SAPEG-MPDA@SPIO/Fe^(3+) NPs could effectively encapsulate the DOX,showing dual pH-and thermal-triggered drug release behavior.In vitro and in vivo studies revealed that SA-MPDA@SPIO/DOX/Fe^(3+) NPs could effectively target to the hepatic tumor tissue,which was possibly due to the specific interaction between SA and the overexpressed E-selectin.This behavior also endowed SA-MPDA@SPIO/DOX/Fe^(3+)NPs with a more precise T1-T2 dual mode contrast imaging effect than the one without SA modification.In addition,SAPEG-MPDA@SPIO/DOX/Fe^(3+) NPs displayed a superior therapeutic effect,which was due to its active targeting ability and combined effects of chemotherapy and photothermal therapy.These results demonstrated that SAPEG-MPDA@SPIO/DOX/Fe^(3+) NPs is an effective targeted nanoplatform for tumor theranostics,having potential value in the effective treatment of hepatic cancer.

Construction and application of oligo-based FISH karyotype of Haynaldia villosa

Haynaldia villosa （L.） Schur （syn. Dasypyrurn villosum （L.） Can- dargy） （2n - 14, genome VV）, a wild relative of wheat, is an impor- tant gene pool for improving wheat quality and disease resistance. Several genes found in H. villosa have been transferred into wheat to improve wheat resistance by the development of alien transloca- tion lines. The seed storage protein loci on chromosome 1V contribute to grain quality （Zhang et al., 2014）.

Effects of linker amino acids on the potency and selectivity of dimeric antimicrobial peptides

Dimerization is an effective strategy for designing antimicrobial peptides that combine the advantages of different native peptides. In this study, we explored the effects of different linker amino acids, including leucine, proline and aminocaproic acid, on the anticancer, antimicrobial and hemolytic activities of the heteromeric antimicrobial peptides AM-1, AM-2, and AM-3. Proline and aminocaproic acid are ideal linkers for increasing the potency and selectivity of heteromeric antimicrobial peptides. The results of MD simulations provided a rationalization for this observation. Both AM-2, which had a proline linker,and AM-3, which had an aminocaproic acid linker, adopted a compact conformation in water and a bent conformation in membranes. This change in the flexible structures of AM-2 and AM-3 could have resulted in decreased binding of these peptides to zwitterionic lipid bilayers and increased damage to mixed lipid bilayers containing acidic phospholipids. In short, these findings obtained via assessing the effects of linker amino acids will contribute to the design of ideal heteromeric antimicrobial peptides with high selectivity and potency.