The studypresents theHalfMax InsertionHeuristic (HMIH) as a novel approach to solving theTravelling SalesmanProblem (TSP). The goal is to outperform existing techniques such as the Farthest Insertion Heuristic (FIH) a...The studypresents theHalfMax InsertionHeuristic (HMIH) as a novel approach to solving theTravelling SalesmanProblem (TSP). The goal is to outperform existing techniques such as the Farthest Insertion Heuristic (FIH) andNearest Neighbour Heuristic (NNH). The paper discusses the limitations of current construction tour heuristics,focusing particularly on the significant margin of error in FIH. It then proposes HMIH as an alternative thatminimizes the increase in tour distance and includes more nodes. HMIH improves tour quality by starting withan initial tour consisting of a ‘minimum’ polygon and iteratively adding nodes using our novel Half Max routine.The paper thoroughly examines and compares HMIH with FIH and NNH via rigorous testing on standard TSPbenchmarks. The results indicate that HMIH consistently delivers superior performance, particularly with respectto tour cost and computational efficiency. HMIH’s tours were sometimes 16% shorter than those generated by FIHand NNH, showcasing its potential and value as a novel benchmark for TSP solutions. The study used statisticalmethods, including Friedman’s Non-parametric Test, to validate the performance of HMIH over FIH and NNH.This guarantees that the identified advantages are statistically significant and consistent in various situations. Thiscomprehensive analysis emphasizes the reliability and efficiency of the heuristic, making a compelling case for itsuse in solving TSP issues. The research shows that, in general, HMIH fared better than FIH in all cases studied,except for a few instances (pr439, eil51, and eil101) where FIH either performed equally or slightly better thanHMIH. HMIH’s efficiency is shown by its improvements in error percentage (δ) and goodness values (g) comparedto FIH and NNH. In the att48 instance, HMIH had an error rate of 6.3%, whereas FIH had 14.6% and NNH had20.9%, indicating that HMIH was closer to the optimal solution. HMIH consistently showed superior performanceacross many benchmarks, with lower percentage error and higher goodness values, suggesting a closer match tothe optimal tour costs. This study substantially contributes to combinatorial optimization by enhancing currentinsertion algorithms and presenting a more efficient solution for the Travelling Salesman Problem. It also createsnew possibilities for progress in heuristic design and optimization methodologies.展开更多
BACKGROUND Peripherally inserted central catheters(PICCs)are commonly used in hospitalized patients with liver cancer for the administration of chemotherapy,nutrition,and other medications.However,PICC-related thrombo...BACKGROUND Peripherally inserted central catheters(PICCs)are commonly used in hospitalized patients with liver cancer for the administration of chemotherapy,nutrition,and other medications.However,PICC-related thrombosis is a serious complication that can lead to morbidity and mortality in this patient population.Several risk factors have been identified for the development of PICC-related thrombosis,including cancer type,stage,comorbidities,and catheter characteristics.Understanding these risk factors and developing a predictive model can help healthcare providers identify high-risk patients and implement preventive measures to reduce the incidence of thrombosis.AIM To analyze the influencing factors of PICC-related thrombosis in hospitalized patients with liver cancer,construct a predictive model,and validate it.METHODS Clinical data of hospitalized patients with liver cancer admitted from January 2020 to December 2023 were collected.Thirty-five cases of PICC-related thrombosis in hospitalized patients with liver cancer were collected,and 220 patients who underwent PICC placement during the same period but did not develop PICC-related thrombosis were randomly selected as controls.A total of 255 samples were collected and used as the training set,and 77 cases were collected as the validation set in a 7:3 ratio.General patient information,case data,catheterization data,coagulation indicators,and Autar Thrombosis Risk Assessment Scale scores were analyzed.Univariate and multivariate unconditional logistic regression analyses were performed on relevant factors,and the value of combined indicators in predicting PICC-related thrombosis in hospitalized patients with liver cancer was evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Univariate analysis showed statistically significant differences(P<0.05)in age,sex,Karnofsky performance status score(KPS),bedridden time,activities of daily living impairment,parenteral nutrition,catheter duration,distant metastasis,and bone marrow suppression between the thrombosis group and the non-thrombosis group.Other aspects had no statistically significant differences(P>0.05).Multivariate regression analysis showed that age≥60 years,KPS score≤50 points,parenteral nutrition,stage III to IV,distant metastasis,bone marrow suppression,and activities of daily living impairment were independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer(P<0.05).Catheter duration of 1-6 months and catheter duration>6 months were protective factors for PICC-related thrombosis(P<0.05).The predictive model for PICC-related thrombosis was obtained as follows:P predictive probability=[exp(Logit P)]/[1+exp(Logit P)],where Logit P=age×1.907+KPS score×2.045+parenteral nutrition×9.467+catheter duration×0.506+tumor-node-metastasis(TNM)staging×2.844+distant metastasis×2.065+bone marrow suppression×2.082+activities of daily living impairment×13.926.ROC curve analysis showed an area under the curve(AUC)of 0.827(95%CI:0.724-0.929,P<0.001),with a corresponding optimal cut-off value of 0.612,sensitivity of 0.755,and specificity of 0.857.Calibration curve analysis showed good consistency between the predicted occurrence of PICC-related thrombosis and actual occurrence(P>0.05).ROC analysis showed AUCs of 0.888 and 0.729 for the training and validation sets,respectively.CONCLUSION Age,KPS score,parenteral nutrition,TNM staging,distant metastasis,bone marrow suppression,and activities of daily living impairment are independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer,while catheter duration is a protective factor for the disease.The predictive model has an AUC of 0.827,indicating high predictive accuracy and clinical value.展开更多
BACKGROUND Peripherally inserted central catheters(PICCs)are an essential infusion route for oncology patients receiving intravenous treatments,but lower extremity veni-puncture is the preferred technique for patients...BACKGROUND Peripherally inserted central catheters(PICCs)are an essential infusion route for oncology patients receiving intravenous treatments,but lower extremity veni-puncture is the preferred technique for patients with superior vena cava syndrome(SVCS).We report the case of a patient with a lower extremity PICC ectopic to the ascending lumbar vein,to indicate and verify PICC catheterisation in the lower extremity is safe and feasible.And hope to provide different per-spectives for clinical PICC venipuncture to get the attention of peers.CASE SUMMARY On 24 August 2022,a 58-year-old male was admitted to our department due to an intermittent cough persisting for over a month,which worsened 10 d prior.Imaging and laboratory investigations suggested the patient with pulmonary malignancy and SVCS.Chemotherapy was not an absolute contraindication in this patient.Lower extremity venipuncture is the preferred technique because administering upper extremity venous transfusion to patients with SVCS can exacerbate oedema in the head,neck,and upper extremities.The patient and his family were informed about the procedure,and informed consent was obtained.After successful puncture and prompt treatment,the patient was discharged,experiencing some relief from symptoms.CONCLUSION Inferior vena cava catheterisation is rare and important for cancer patients with SVCS,particularly in complex situations involving ectopic placement.展开更多
Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution rea...Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.展开更多
Central venous catheterization(CVC) is an invasive procedure for administering fluids,nutrients,and drugs;monitoring central venous pressure;performing pulmonary artery catheterization;and placing transvenous pacemake...Central venous catheterization(CVC) is an invasive procedure for administering fluids,nutrients,and drugs;monitoring central venous pressure;performing pulmonary artery catheterization;and placing transvenous pacemakers in intensive care units and all specialties,from anesthesia to emergency medicine,for the treatment of trauma and hemodynamically unstable pediatric and adult patients.[1,2]Complications have been observed in more than 15% of patients who underwent CVC.Mechanical,infectious,and thrombotic complications have been reported in 5%–19%,5%–26%,and 2%–26% of patients,respectively.[3] Malposition,on the other hand,is common in subclavian catheter insertion and is usually associated with an initially misplaced guidewire.[4]展开更多
Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F....Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.展开更多
Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-st...Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.展开更多
Heat augmentation techniques play a vital role in the heating and cooling processes in industries,including solar collectors and many applications that utilize heat exchangers.Several studies are based on inserting fi...Heat augmentation techniques play a vital role in the heating and cooling processes in industries,including solar collectors and many applications that utilize heat exchangers.Several studies are based on inserting fillers inside the tubes to enhance heat transfer.This investigation considered the effects of twisted tapes with large holes on a tubular heat exchanger’s(HX)heat transmission,pressure drop,and thermal boosting factor.In the experimental section,counter-swirl flow generators used twisted tapes with pairs of 1.0 cm-diameter holes and changes in porosity(Rp)at 1.30%and 2.70%.In the experiments,air was utilized as a working fluid in a tube with a circular cross-section.The turbulent flow was considered,with Reynolds numbers(Re)domain from 4800 to 9500,and a boundary condition with a uniform wall heat flux was constructed.The findings expound that when the number of holes rose,the Nusselt number(Nu),the factor of friction(f),and the thermal enhancement factor(η)all increased as well.Additionally,as the friction factor increased,the Nusselt number of the tape-equipped tube was noticeably higher.Additionally,it was discovered that the friction factor was between 70%and 94%lower than the values of the tube without tape,while the(Nu)was between 87%and 97%higher than the conventional tube values.The maximum value ofηis 89%.According to the experimental results,empirical correlations for Nu,f,andηwere also generated.展开更多
BACKGROUND Benign rectal strictures can be categorized as primary(disease-related)and secondary(surgical anastomosis-related).Secondary strictures arise from surgical complications,whereas primary strictures have dive...BACKGROUND Benign rectal strictures can be categorized as primary(disease-related)and secondary(surgical anastomosis-related).Secondary strictures arise from surgical complications,whereas primary strictures have diverse etiologies,including various inflammatory conditions.Benign strictures are usually managed by surgery and endoscopy.We present an unusual etiology of benign rectal stricture caused by the repeated insertion of foreign objects into the rectum for sexual purposes,resulting in rectal injury and subsequent chronic inflammation.CASE SUMMARY A 53-year-old man presented to the outpatient clinic of the Colorectal Surgery Department with symptoms of chronic constipation and bloody stools.The patient previously experienced rectal injury due to foreign object insertion for sexual purposes.Colonoscopy revealed benign circumferential narrowing of the rectum.He underwent treatment by endoscopic argon plasma coagulation and balloon dilation and follow-up as an outpatient for 4 months.A colonoscopy at the end of the follow-up period revealed no evidence of rectal stricture relapse.CONCLUSION A history of rectal injury,followed by chronic inflammation,should be considered in patients with benign rectal strictures.Management with endoscopic argon plasma coagulation and balloon dilation can prevent the need for surgical resection of benign rectal strictures.展开更多
Velamentous insertion of the umbilical cord corresponds to the insertion of the cord directly on amniotic membranes. It is a rare situation whose frequency varies from 0.5% to 1.69% of single pregnancies. It must be d...Velamentous insertion of the umbilical cord corresponds to the insertion of the cord directly on amniotic membranes. It is a rare situation whose frequency varies from 0.5% to 1.69% of single pregnancies. It must be diagnosed during the morphological ultrasound of the 2nd trimester, actively looking for the association with a vasa previa, due to the risk of fetal haemorrhagic threat. We report an antenatal diagnosis of velamentous cord insertion and its management with literature review.展开更多
Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size ...Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary(API)and shot times.To quantitatively evaluate the effect of energy absorption for ceramic plates,a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments(SDCF).Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated.The results indicate that the distribution feature of ceramic fragments in the range of 0.25-2.25 mm is Gaussian distribution.Compared with Type 56 of API(56-API),ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution,whose average equivalence size decreases by 6.5%,corresponding to increasing by 83.9%of estimated energy absorption.Besides,the ability of CCBIPs to resist the third shot is significantly weakened,whose estimated energy absorption decreases by 58.8%compared with the first shot.More concentrated distribution and fewer fragments are formed after the third shot,the average equivalence size of ceramic fragments increases by 6.9%,which may attribute to the micro-cracks induced by the previous two shots.展开更多
In-process damage to a cutting tool degrades the surfacenish of the job shaped by machining and causes a signicantnancial loss.This stimulates the need for Tool Condition Monitoring(TCM)t...In-process damage to a cutting tool degrades the surfacenish of the job shaped by machining and causes a signicantnancial loss.This stimulates the need for Tool Condition Monitoring(TCM)to assist detection of failure before it extends to the worse phase.Machine Learning(ML)based TCM has been extensively explored in the last decade.However,most of the research is now directed toward Deep Learning(DL).The“Deep”formulation,hierarchical compositionality,distributed representation and end-to-end learning of Neural Nets need to be explored to create a generalized TCM framework to perform eciently in a high-noise environment of cross-domain machining.With this motivation,the design of dierent CNN(Convolutional Neural Network)architectures such as AlexNet,ResNet-50,LeNet-5,and VGG-16 is presented in this paper.Real-time spindle vibrations corresponding to healthy and various faulty congurations of milling cutter were acquired.This data was transformed into the time-frequency domain and further processed by proposed architectures in graphical form,i.e.,spectrogram.The model is trained,tested,and validated considering dierent datasets and showcased promising results.展开更多
The In segregation and its suppression in InGaAs/AlGaAs quantum well are investigated by using high-resolution x-ray diffraction(XRD)and photoluminescence(PL),combined with the state-of-the-art aberration corrected sc...The In segregation and its suppression in InGaAs/AlGaAs quantum well are investigated by using high-resolution x-ray diffraction(XRD)and photoluminescence(PL),combined with the state-of-the-art aberration corrected scanning transmission electron microscopy(Cs-STEM)techniques.To facility our study,we grow two multiple quantum wells(MQWs)samples,which are almost identical except that in sample B a thin GaAs layer is inserted in each of the InGaAs well and AlGaAs barrier layer comparing to pristine InGaAs/AlGaAs MQWs(sample A).Our study indeed shows the direct evidences that In segregation occurs in the InGaAs/AlGaAs interface,and the effect of the Ga As insertion layer on suppressing the segregation of In atoms is also demonstrated on the atomic-scale.Therefore,the atomic-scale insights are provided to understand the segregation behavior of In atoms and to unravel the underlying mechanism of the effect of GaAs insertion layer on the improvement of crystallinity,interface roughness,and further an enhanced optical performance of InGaAs/AlGaAs QWs.展开更多
In this work, the liquid-liquid two-phase mass transfer characteristics in the microchannel with deformed insert were studied. The experiment used di-(2-ethylhexyl) phosphoric acid/kerosene-Cu^(2+)as the mass transfer...In this work, the liquid-liquid two-phase mass transfer characteristics in the microchannel with deformed insert were studied. The experiment used di-(2-ethylhexyl) phosphoric acid/kerosene-Cu^(2+)as the mass transfer evaluation system. The effects of some key factors such as the total flow velocity,channel inner diameter, channel length, insert diameter, extractant concentration on the extraction efficiency and mass transfer coefficient were systematically investigated. Compared with a simple microreactor, the liquid-liquid mass transfer enhancement effect of the insert was quantitatively analyzed. The study found that the regular deformation of the insert could cause fluid interface deformation and promote flow state chaos, effectively increasing the mass transfer rate. And the enhancement effect of the insert was more significant at high flow velocities. The highest mass transfer coefficient in the microchannel with deformed insert was 7.886 s^(-1), the enhancement factor could reach 4.17. And only needed 0.095 s to approach the extraction equilibrium. The deformed center insert exhibited an effective liquid-liquid mass transfer enhancement effect, which can be used as a micro-chemical process enhancement method to be applied in the fields of higher throughput mass transfer and chemical synthesis,and at the same time provide ideas for development and structural optimization of microreactors.展开更多
DEAR EDITOR,Insertion sequences(ISs) are the simplest structural transposable elements(TEs) in prokaryotes, consisting only of a transposase coding sequence and its bilateral short terminal inverted repeats. Due to th...DEAR EDITOR,Insertion sequences(ISs) are the simplest structural transposable elements(TEs) in prokaryotes, consisting only of a transposase coding sequence and its bilateral short terminal inverted repeats. Due to their gradually streamlined genomic construction, TEs rarely exist in the genomes of obligate endosymbionts. However, TE content, especially ISs.展开更多
The recognized energy storage mechanism of neutral aqueous zinc-manganese batteries is the co-insertion/extrusion of H^(+) and Zn^(2+) ions.However,modulating the kinetics of a single H^(+) or Zn^(2+) ion is scarce,wh...The recognized energy storage mechanism of neutral aqueous zinc-manganese batteries is the co-insertion/extrusion of H^(+) and Zn^(2+) ions.However,modulating the kinetics of a single H^(+) or Zn^(2+) ion is scarce,which can provide meaningful insights into the energy storage mechanism of Zn ion batteries.Herein,a distinctive doubly electric field in-situ induced cationic anchoring of two-dimensional layered MnO_(2) is successfully constructed to modulate the insertion/extrusion of a single H^(+) or Zn^(2+) ion.As a result,regulating the intercalation of different metal ions can precisely achieve the accelerated induction for the individual H^(+) or Zn^(2+) ions intercalation/deintercalation.Moreover,the introduction of metal ions stabilizes the lattice distortion and alleviates the irreparable structural collapse,leading to an increase in the H^(+)/Zn^(2+) storage sites,efficiently diminishing the stagnation of the ordered structure and creating the more open channels,which is conducive to facilitating the diffusion of ions.This work delivers some innovative insights into pre-embedding strategies,and also serves as a precious reference for the cathode development of advanced aqueous batteries.展开更多
This research tests the effect of introducing turbulators of a new type into a circular tube heat exchanger under a constant and uniform longitudinal heatflux condition.A 45 mm diameter copper tube with a length of 1,3...This research tests the effect of introducing turbulators of a new type into a circular tube heat exchanger under a constant and uniform longitudinal heatflux condition.A 45 mm diameter copper tube with a length of 1,350 mm is utilized with a solid disk being inserted inside the tube,which consists of three sections,each one containing two slots.The slot is cut at a 45 degree angle toward the inner tube surface,which results in diverging theflow toward the inner hot tube surface in order to enhance the heat transfer process.Air is considered as the workingfluid with Prandtl number 0.71.The Reynolds number spans the interval from 6,000–13,500,which indicates that the consideredflow is turbulent.The heat exchanger performance is studied and analyzed in terms of average Nusselt number.The experimental results show that the Nusselt number value is directly proportional to the increase of the Reynolds number,and the number of turbulators inserts.With the use of three novel turbulators,the heat transfer was about 3.15 times higher than that in the smooth tube and the friction factor was about 1.11.展开更多
Sexual reproduction in plants is the main pathway for creating new genetic combinations in modern agriculture.In heterozygous plants,after the identification of a plant with desired traits,vegetative propagation(cloni...Sexual reproduction in plants is the main pathway for creating new genetic combinations in modern agriculture.In heterozygous plants,after the identification of a plant with desired traits,vegetative propagation(cloning)is the primary path to create genetically uniform plants.Another natural plant mechanism that creates genetically uniform plants(clones)is apomixis.In fruit crops like citrus and mango,sporophytic apomixis results in polyembryony,where seeds contain multiple embryos,one of which is sexually originated and the others are vegetative clones of the parent mother tree.Utilizing the mango genome and genetic analysis of a diverse germplasm collection,we identified MiRWP as the gene that causes polyembryony in mango.There is a strong correlation between a specific insertion in the gene’s promoter region and altered expression in flowers and developing fruitlets,inducing multiple embryos.The MiRWP gene is an ortholog of CitRWP that causes polyembryony in citrus.Based on the data,we speculate that promoter insertion events,which occurred independently in citrus and mango,induced nucellar embryogenesis.The results suggest convergent evolution of polyembryony in the two species.Further work is required to demonstrate the utility of these genes(mango and citrus)in other biological systems as a tool for the clonal production of other crops.展开更多
In this work, the computational fluid dynamics method is used to study the liquid hydrodynamics behavior in the microchannel without central insert(MC1) and the central insert microchannel(MC2), respectively. The maxi...In this work, the computational fluid dynamics method is used to study the liquid hydrodynamics behavior in the microchannel without central insert(MC1) and the central insert microchannel(MC2), respectively. The maximum deviation between simulation and experiment is 24%. The formations of flow patterns are explained based on contours and force analysis where the flow pattern maps are established by two-phase flow rate. The effects of aqueous phase viscosity and two-phase flow rate on the characteristic sizes of each flow pattern are also explored. Specifically, four unconventional flow patterns are found in MC2, namely the unique droplet flow, the unique slug flow, the unique coarse annular flow and the unique film annular flow. Though the insert occupies part of the channel, the pressure difference in the channel is significantly reduced compared with MC1. Moreover, the insert significantly changes the formation velocity range of each flow pattern, greatly broadens the formation range of annular flow and also has an important influence on the characteristic size of the flow pattern. The organic-phase dimensionless axial size(Lo/W) and the dimensionless radial size(Do/W) of the droplet(slug) are negatively related to the aqueous-phase viscosity(μa) and flow rate(ua). The Do/W of the annular is negatively correlated with μaand positively correlated with organic-phase flow rate(uo). This study provides direct numerical evidence that the insert is key to the formation of bicontinuous phase flow pattern, as well as further strengthens our understanding of the flow characteristics and optimization design of insert microchannels.展开更多
基金the Centre of Excellence in Mobile and e-Services,the University of Zululand,Kwadlangezwa,South Africa.
文摘The studypresents theHalfMax InsertionHeuristic (HMIH) as a novel approach to solving theTravelling SalesmanProblem (TSP). The goal is to outperform existing techniques such as the Farthest Insertion Heuristic (FIH) andNearest Neighbour Heuristic (NNH). The paper discusses the limitations of current construction tour heuristics,focusing particularly on the significant margin of error in FIH. It then proposes HMIH as an alternative thatminimizes the increase in tour distance and includes more nodes. HMIH improves tour quality by starting withan initial tour consisting of a ‘minimum’ polygon and iteratively adding nodes using our novel Half Max routine.The paper thoroughly examines and compares HMIH with FIH and NNH via rigorous testing on standard TSPbenchmarks. The results indicate that HMIH consistently delivers superior performance, particularly with respectto tour cost and computational efficiency. HMIH’s tours were sometimes 16% shorter than those generated by FIHand NNH, showcasing its potential and value as a novel benchmark for TSP solutions. The study used statisticalmethods, including Friedman’s Non-parametric Test, to validate the performance of HMIH over FIH and NNH.This guarantees that the identified advantages are statistically significant and consistent in various situations. Thiscomprehensive analysis emphasizes the reliability and efficiency of the heuristic, making a compelling case for itsuse in solving TSP issues. The research shows that, in general, HMIH fared better than FIH in all cases studied,except for a few instances (pr439, eil51, and eil101) where FIH either performed equally or slightly better thanHMIH. HMIH’s efficiency is shown by its improvements in error percentage (δ) and goodness values (g) comparedto FIH and NNH. In the att48 instance, HMIH had an error rate of 6.3%, whereas FIH had 14.6% and NNH had20.9%, indicating that HMIH was closer to the optimal solution. HMIH consistently showed superior performanceacross many benchmarks, with lower percentage error and higher goodness values, suggesting a closer match tothe optimal tour costs. This study substantially contributes to combinatorial optimization by enhancing currentinsertion algorithms and presenting a more efficient solution for the Travelling Salesman Problem. It also createsnew possibilities for progress in heuristic design and optimization methodologies.
文摘BACKGROUND Peripherally inserted central catheters(PICCs)are commonly used in hospitalized patients with liver cancer for the administration of chemotherapy,nutrition,and other medications.However,PICC-related thrombosis is a serious complication that can lead to morbidity and mortality in this patient population.Several risk factors have been identified for the development of PICC-related thrombosis,including cancer type,stage,comorbidities,and catheter characteristics.Understanding these risk factors and developing a predictive model can help healthcare providers identify high-risk patients and implement preventive measures to reduce the incidence of thrombosis.AIM To analyze the influencing factors of PICC-related thrombosis in hospitalized patients with liver cancer,construct a predictive model,and validate it.METHODS Clinical data of hospitalized patients with liver cancer admitted from January 2020 to December 2023 were collected.Thirty-five cases of PICC-related thrombosis in hospitalized patients with liver cancer were collected,and 220 patients who underwent PICC placement during the same period but did not develop PICC-related thrombosis were randomly selected as controls.A total of 255 samples were collected and used as the training set,and 77 cases were collected as the validation set in a 7:3 ratio.General patient information,case data,catheterization data,coagulation indicators,and Autar Thrombosis Risk Assessment Scale scores were analyzed.Univariate and multivariate unconditional logistic regression analyses were performed on relevant factors,and the value of combined indicators in predicting PICC-related thrombosis in hospitalized patients with liver cancer was evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Univariate analysis showed statistically significant differences(P<0.05)in age,sex,Karnofsky performance status score(KPS),bedridden time,activities of daily living impairment,parenteral nutrition,catheter duration,distant metastasis,and bone marrow suppression between the thrombosis group and the non-thrombosis group.Other aspects had no statistically significant differences(P>0.05).Multivariate regression analysis showed that age≥60 years,KPS score≤50 points,parenteral nutrition,stage III to IV,distant metastasis,bone marrow suppression,and activities of daily living impairment were independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer(P<0.05).Catheter duration of 1-6 months and catheter duration>6 months were protective factors for PICC-related thrombosis(P<0.05).The predictive model for PICC-related thrombosis was obtained as follows:P predictive probability=[exp(Logit P)]/[1+exp(Logit P)],where Logit P=age×1.907+KPS score×2.045+parenteral nutrition×9.467+catheter duration×0.506+tumor-node-metastasis(TNM)staging×2.844+distant metastasis×2.065+bone marrow suppression×2.082+activities of daily living impairment×13.926.ROC curve analysis showed an area under the curve(AUC)of 0.827(95%CI:0.724-0.929,P<0.001),with a corresponding optimal cut-off value of 0.612,sensitivity of 0.755,and specificity of 0.857.Calibration curve analysis showed good consistency between the predicted occurrence of PICC-related thrombosis and actual occurrence(P>0.05).ROC analysis showed AUCs of 0.888 and 0.729 for the training and validation sets,respectively.CONCLUSION Age,KPS score,parenteral nutrition,TNM staging,distant metastasis,bone marrow suppression,and activities of daily living impairment are independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer,while catheter duration is a protective factor for the disease.The predictive model has an AUC of 0.827,indicating high predictive accuracy and clinical value.
基金the Chongqing Medical Scientific Research Project(a joint project of the Chongqing Health Commission and Science and Technology Bureau),No.2020FYYX046。
文摘BACKGROUND Peripherally inserted central catheters(PICCs)are an essential infusion route for oncology patients receiving intravenous treatments,but lower extremity veni-puncture is the preferred technique for patients with superior vena cava syndrome(SVCS).We report the case of a patient with a lower extremity PICC ectopic to the ascending lumbar vein,to indicate and verify PICC catheterisation in the lower extremity is safe and feasible.And hope to provide different per-spectives for clinical PICC venipuncture to get the attention of peers.CASE SUMMARY On 24 August 2022,a 58-year-old male was admitted to our department due to an intermittent cough persisting for over a month,which worsened 10 d prior.Imaging and laboratory investigations suggested the patient with pulmonary malignancy and SVCS.Chemotherapy was not an absolute contraindication in this patient.Lower extremity venipuncture is the preferred technique because administering upper extremity venous transfusion to patients with SVCS can exacerbate oedema in the head,neck,and upper extremities.The patient and his family were informed about the procedure,and informed consent was obtained.After successful puncture and prompt treatment,the patient was discharged,experiencing some relief from symptoms.CONCLUSION Inferior vena cava catheterisation is rare and important for cancer patients with SVCS,particularly in complex situations involving ectopic placement.
基金financially supported by National Natural Science Foundation of China(No.22209049,22075102,22005120)Natural Science Foundation of Guangdong Province(No.2023A1515012804)Fundamental Research Funds for the Central Universities(No.2022ZYGXZR048)。
文摘Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.
文摘Central venous catheterization(CVC) is an invasive procedure for administering fluids,nutrients,and drugs;monitoring central venous pressure;performing pulmonary artery catheterization;and placing transvenous pacemakers in intensive care units and all specialties,from anesthesia to emergency medicine,for the treatment of trauma and hemodynamically unstable pediatric and adult patients.[1,2]Complications have been observed in more than 15% of patients who underwent CVC.Mechanical,infectious,and thrombotic complications have been reported in 5%–19%,5%–26%,and 2%–26% of patients,respectively.[3] Malposition,on the other hand,is common in subclavian catheter insertion and is usually associated with an initially misplaced guidewire.[4]
基金supported by grants from the National Natural Science Foundation of China(31901835)the Science and Technology Planning Project of Henan Province of China(212102110145)the International(Regional)Cooperation and Exchange Program of the National Natural Science Foundation of China(31961143018).
文摘Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.
基金the National Key R&D Program of China(Nos.2018YFD0901506,2018YFD0900305)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018 SDKJ0406-3)。
文摘Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.
文摘Heat augmentation techniques play a vital role in the heating and cooling processes in industries,including solar collectors and many applications that utilize heat exchangers.Several studies are based on inserting fillers inside the tubes to enhance heat transfer.This investigation considered the effects of twisted tapes with large holes on a tubular heat exchanger’s(HX)heat transmission,pressure drop,and thermal boosting factor.In the experimental section,counter-swirl flow generators used twisted tapes with pairs of 1.0 cm-diameter holes and changes in porosity(Rp)at 1.30%and 2.70%.In the experiments,air was utilized as a working fluid in a tube with a circular cross-section.The turbulent flow was considered,with Reynolds numbers(Re)domain from 4800 to 9500,and a boundary condition with a uniform wall heat flux was constructed.The findings expound that when the number of holes rose,the Nusselt number(Nu),the factor of friction(f),and the thermal enhancement factor(η)all increased as well.Additionally,as the friction factor increased,the Nusselt number of the tape-equipped tube was noticeably higher.Additionally,it was discovered that the friction factor was between 70%and 94%lower than the values of the tube without tape,while the(Nu)was between 87%and 97%higher than the conventional tube values.The maximum value ofηis 89%.According to the experimental results,empirical correlations for Nu,f,andηwere also generated.
文摘BACKGROUND Benign rectal strictures can be categorized as primary(disease-related)and secondary(surgical anastomosis-related).Secondary strictures arise from surgical complications,whereas primary strictures have diverse etiologies,including various inflammatory conditions.Benign strictures are usually managed by surgery and endoscopy.We present an unusual etiology of benign rectal stricture caused by the repeated insertion of foreign objects into the rectum for sexual purposes,resulting in rectal injury and subsequent chronic inflammation.CASE SUMMARY A 53-year-old man presented to the outpatient clinic of the Colorectal Surgery Department with symptoms of chronic constipation and bloody stools.The patient previously experienced rectal injury due to foreign object insertion for sexual purposes.Colonoscopy revealed benign circumferential narrowing of the rectum.He underwent treatment by endoscopic argon plasma coagulation and balloon dilation and follow-up as an outpatient for 4 months.A colonoscopy at the end of the follow-up period revealed no evidence of rectal stricture relapse.CONCLUSION A history of rectal injury,followed by chronic inflammation,should be considered in patients with benign rectal strictures.Management with endoscopic argon plasma coagulation and balloon dilation can prevent the need for surgical resection of benign rectal strictures.
文摘Velamentous insertion of the umbilical cord corresponds to the insertion of the cord directly on amniotic membranes. It is a rare situation whose frequency varies from 0.5% to 1.69% of single pregnancies. It must be diagnosed during the morphological ultrasound of the 2nd trimester, actively looking for the association with a vasa previa, due to the risk of fetal haemorrhagic threat. We report an antenatal diagnosis of velamentous cord insertion and its management with literature review.
基金financially supported by the National Key Research&Development Project(2017YFB1103505)the Military Logistics Research Program(XXXC002)of China。
文摘Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary(API)and shot times.To quantitatively evaluate the effect of energy absorption for ceramic plates,a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments(SDCF).Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated.The results indicate that the distribution feature of ceramic fragments in the range of 0.25-2.25 mm is Gaussian distribution.Compared with Type 56 of API(56-API),ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution,whose average equivalence size decreases by 6.5%,corresponding to increasing by 83.9%of estimated energy absorption.Besides,the ability of CCBIPs to resist the third shot is significantly weakened,whose estimated energy absorption decreases by 58.8%compared with the first shot.More concentrated distribution and fewer fragments are formed after the third shot,the average equivalence size of ceramic fragments increases by 6.9%,which may attribute to the micro-cracks induced by the previous two shots.
文摘In-process damage to a cutting tool degrades the surfacenish of the job shaped by machining and causes a signicantnancial loss.This stimulates the need for Tool Condition Monitoring(TCM)to assist detection of failure before it extends to the worse phase.Machine Learning(ML)based TCM has been extensively explored in the last decade.However,most of the research is now directed toward Deep Learning(DL).The“Deep”formulation,hierarchical compositionality,distributed representation and end-to-end learning of Neural Nets need to be explored to create a generalized TCM framework to perform eciently in a high-noise environment of cross-domain machining.With this motivation,the design of dierent CNN(Convolutional Neural Network)architectures such as AlexNet,ResNet-50,LeNet-5,and VGG-16 is presented in this paper.Real-time spindle vibrations corresponding to healthy and various faulty congurations of milling cutter were acquired.This data was transformed into the time-frequency domain and further processed by proposed architectures in graphical form,i.e.,spectrogram.The model is trained,tested,and validated considering dierent datasets and showcased promising results.
基金X.H.gratefully acknowledges the financial support from the National Natural Science Foundation of China(Grant No.21902096)the Scientific Research Foundation of Shaanxi University of Science and Technology(Grant No.126061803)+1 种基金S.M.and B.X.thank the National Natural Science Foundation of China(Grant No.21972103)the Shanxi Provincial Key Innovative Research Team in Science and Technology(Grant No.201703D111026).
文摘The In segregation and its suppression in InGaAs/AlGaAs quantum well are investigated by using high-resolution x-ray diffraction(XRD)and photoluminescence(PL),combined with the state-of-the-art aberration corrected scanning transmission electron microscopy(Cs-STEM)techniques.To facility our study,we grow two multiple quantum wells(MQWs)samples,which are almost identical except that in sample B a thin GaAs layer is inserted in each of the InGaAs well and AlGaAs barrier layer comparing to pristine InGaAs/AlGaAs MQWs(sample A).Our study indeed shows the direct evidences that In segregation occurs in the InGaAs/AlGaAs interface,and the effect of the Ga As insertion layer on suppressing the segregation of In atoms is also demonstrated on the atomic-scale.Therefore,the atomic-scale insights are provided to understand the segregation behavior of In atoms and to unravel the underlying mechanism of the effect of GaAs insertion layer on the improvement of crystallinity,interface roughness,and further an enhanced optical performance of InGaAs/AlGaAs QWs.
基金financially supported by the National Natural Science Foundation of China (21776180)the Key Research Development Project of Sichuan Province (21ZDYF4086)the National Natural Science Foundation of China (22108177)。
文摘In this work, the liquid-liquid two-phase mass transfer characteristics in the microchannel with deformed insert were studied. The experiment used di-(2-ethylhexyl) phosphoric acid/kerosene-Cu^(2+)as the mass transfer evaluation system. The effects of some key factors such as the total flow velocity,channel inner diameter, channel length, insert diameter, extractant concentration on the extraction efficiency and mass transfer coefficient were systematically investigated. Compared with a simple microreactor, the liquid-liquid mass transfer enhancement effect of the insert was quantitatively analyzed. The study found that the regular deformation of the insert could cause fluid interface deformation and promote flow state chaos, effectively increasing the mass transfer rate. And the enhancement effect of the insert was more significant at high flow velocities. The highest mass transfer coefficient in the microchannel with deformed insert was 7.886 s^(-1), the enhancement factor could reach 4.17. And only needed 0.095 s to approach the extraction equilibrium. The deformed center insert exhibited an effective liquid-liquid mass transfer enhancement effect, which can be used as a micro-chemical process enhancement method to be applied in the fields of higher throughput mass transfer and chemical synthesis,and at the same time provide ideas for development and structural optimization of microreactors.
基金supported by the National Natural Science Foundation of China (31830084, 32070466)Fundamental Research Funds for the Central Universities,Nankai University (96172158,96173250, 91822294)。
文摘DEAR EDITOR,Insertion sequences(ISs) are the simplest structural transposable elements(TEs) in prokaryotes, consisting only of a transposase coding sequence and its bilateral short terminal inverted repeats. Due to their gradually streamlined genomic construction, TEs rarely exist in the genomes of obligate endosymbionts. However, TE content, especially ISs.
基金supported by the Opening Project of the State Key Laboratory of Advanced Chemical Power SourcesGuizhou Provincial Science and Technology Projects(QKHJC–ZK[2021]YB057)+2 种基金the Growth Project of Young Scientific and Technological Talents in Colleges and Universities of Guizhou Province(QKHJCKYZ[2021]252)the Reward and Subsidy Fund Project of Guizhou Education University(Z20210108)the Doctoral Program of Guizhou Education University(2019BS022)。
文摘The recognized energy storage mechanism of neutral aqueous zinc-manganese batteries is the co-insertion/extrusion of H^(+) and Zn^(2+) ions.However,modulating the kinetics of a single H^(+) or Zn^(2+) ion is scarce,which can provide meaningful insights into the energy storage mechanism of Zn ion batteries.Herein,a distinctive doubly electric field in-situ induced cationic anchoring of two-dimensional layered MnO_(2) is successfully constructed to modulate the insertion/extrusion of a single H^(+) or Zn^(2+) ion.As a result,regulating the intercalation of different metal ions can precisely achieve the accelerated induction for the individual H^(+) or Zn^(2+) ions intercalation/deintercalation.Moreover,the introduction of metal ions stabilizes the lattice distortion and alleviates the irreparable structural collapse,leading to an increase in the H^(+)/Zn^(2+) storage sites,efficiently diminishing the stagnation of the ordered structure and creating the more open channels,which is conducive to facilitating the diffusion of ions.This work delivers some innovative insights into pre-embedding strategies,and also serves as a precious reference for the cathode development of advanced aqueous batteries.
文摘This research tests the effect of introducing turbulators of a new type into a circular tube heat exchanger under a constant and uniform longitudinal heatflux condition.A 45 mm diameter copper tube with a length of 1,350 mm is utilized with a solid disk being inserted inside the tube,which consists of three sections,each one containing two slots.The slot is cut at a 45 degree angle toward the inner tube surface,which results in diverging theflow toward the inner hot tube surface in order to enhance the heat transfer process.Air is considered as the workingfluid with Prandtl number 0.71.The Reynolds number spans the interval from 6,000–13,500,which indicates that the consideredflow is turbulent.The heat exchanger performance is studied and analyzed in terms of average Nusselt number.The experimental results show that the Nusselt number value is directly proportional to the increase of the Reynolds number,and the number of turbulators inserts.With the use of three novel turbulators,the heat transfer was about 3.15 times higher than that in the smooth tube and the friction factor was about 1.11.
基金The research was supported by Research Grant No.IS-5106-18R from BARD,The United States-Israel Binational Agricultural Research and Development Fund(granted to A.S.,D.N.K.,Y.C.,and R.O.)by grants No.203-0859(granted to A.S.and R.O.)No.203-0110(granted to Y.C.)from the Chief Scientist of the Israeli Ministry of Agriculture.D.N.K.was supported by a grant from the USDA National Institute of Food and Agriculture(USDA-NIFA 2018-51181-28375).
文摘Sexual reproduction in plants is the main pathway for creating new genetic combinations in modern agriculture.In heterozygous plants,after the identification of a plant with desired traits,vegetative propagation(cloning)is the primary path to create genetically uniform plants.Another natural plant mechanism that creates genetically uniform plants(clones)is apomixis.In fruit crops like citrus and mango,sporophytic apomixis results in polyembryony,where seeds contain multiple embryos,one of which is sexually originated and the others are vegetative clones of the parent mother tree.Utilizing the mango genome and genetic analysis of a diverse germplasm collection,we identified MiRWP as the gene that causes polyembryony in mango.There is a strong correlation between a specific insertion in the gene’s promoter region and altered expression in flowers and developing fruitlets,inducing multiple embryos.The MiRWP gene is an ortholog of CitRWP that causes polyembryony in citrus.Based on the data,we speculate that promoter insertion events,which occurred independently in citrus and mango,induced nucellar embryogenesis.The results suggest convergent evolution of polyembryony in the two species.Further work is required to demonstrate the utility of these genes(mango and citrus)in other biological systems as a tool for the clonal production of other crops.
基金supported by the National Natural Science Foundation of China(21776180,22108177)the Key Research Development Project of Sichuan Province(21ZDYF4086).
文摘In this work, the computational fluid dynamics method is used to study the liquid hydrodynamics behavior in the microchannel without central insert(MC1) and the central insert microchannel(MC2), respectively. The maximum deviation between simulation and experiment is 24%. The formations of flow patterns are explained based on contours and force analysis where the flow pattern maps are established by two-phase flow rate. The effects of aqueous phase viscosity and two-phase flow rate on the characteristic sizes of each flow pattern are also explored. Specifically, four unconventional flow patterns are found in MC2, namely the unique droplet flow, the unique slug flow, the unique coarse annular flow and the unique film annular flow. Though the insert occupies part of the channel, the pressure difference in the channel is significantly reduced compared with MC1. Moreover, the insert significantly changes the formation velocity range of each flow pattern, greatly broadens the formation range of annular flow and also has an important influence on the characteristic size of the flow pattern. The organic-phase dimensionless axial size(Lo/W) and the dimensionless radial size(Do/W) of the droplet(slug) are negatively related to the aqueous-phase viscosity(μa) and flow rate(ua). The Do/W of the annular is negatively correlated with μaand positively correlated with organic-phase flow rate(uo). This study provides direct numerical evidence that the insert is key to the formation of bicontinuous phase flow pattern, as well as further strengthens our understanding of the flow characteristics and optimization design of insert microchannels.