As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays...As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays a pivotal role in MEC performance but remains challenging due to complex task topologies,conflicting objectives,and limited resources.This paper addresses high-dimensional multi-objective offloading for serial heterogeneous tasks in MEC.We jointly consider task heterogeneity,high-dimensional objectives,and flexible resource scheduling,modeling the problem as a Many-objective optimization.To solve it,we propose a flexible framework integrating an improved cooperative co-evolutionary algorithm based on decomposition(MOCC/D)and a flexible scheduling strategy.Experimental results on benchmark functions and simulation scenarios show that the proposed method outperforms existing approaches in both convergence and solution quality.展开更多
Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonra...Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses.However,how these groups synergistically affect the enhancement beyond passivation is still unclear.Specifically,isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives.Here,we report two isomeric carbazolyl bisphosphonate additives,2,7-Cz BP and 3,6-Cz BP.The isomerism effect on passivation and charge transport process was studied.The two molecules have similar passivation effects through multiple interactions,e.g.,P=O···Pb,P=O···H–N and N–H···I.2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport.Power conversion efficiencies(PCEs)of 25.88%and 21.04%were achieved for 0.09 cm^(2)devices and 14 cm^(2)modules after 2,7-Cz BP treatment,respectively.The devices exhibited enhanced operational stability maintaining 95%of initial PCE after 1000 h of continuous maximum power point tracking.This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives,which paves the way for innovation of next-generation multifunctional aromatic additives.展开更多
Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-（4-N,N-di（2-acetoxyethyl）-amino）-phenylene-（3,4-dibutyl）-thien-5]-E-vinylg-5,5-...Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-（4-N,N-di（2-acetoxyethyl）-amino）-phenylene-（3,4-dibutyl）-thien-5]-E-vinylg-5,5-dimethyl-2,5-dihydrofuran （FTC） in a few solvents have been studied using the time-dependent density functional theory in combination with the polarizable continuum model. It is shown that the maximum absorption peaks of the ro-tamers have difference of nearly 30 nm both in vacuum and in solutions. The population of the rotamers changes a lot in different solvents. Based on the geometries optimized by Hartree-Fock method, the Maxwell-Boltzmann averaged absorption has been calculated and the maximum absorption peak is in good agreement with experiment. It indicates that the bond length alternation can have an important effect on the optical spectra.展开更多
Aims:Evidence is emerging that,in the setting of isomerism,the atrial and bronchial arrangement are not always concordant,nor are these patterns always harmonious with the arrangement of the abdominal organs.We aimed ...Aims:Evidence is emerging that,in the setting of isomerism,the atrial and bronchial arrangement are not always concordant,nor are these patterns always harmonious with the arrangement of the abdominal organs.We aimed to evaluate the concordance between these features in a cohort of patients with cardiac malformations in the setting of known isomerism,seeking to determine whether it was feasible to assess complexity on this basis,in this regard taking note of the potential value of bronchial as opposed to appendage morphology.Methods and Results:We studied 78 patients known to have isomerism of the bronchuses,43 with right and 35 with left isomerism.Appendage anatomy could be determined in 49 cases(63%),all but one of these being concordant with bronchial anatomy.When assessing abdominal features,in only 59 cases(76%)was splenic morphology in keeping with the thoracic findings.As expected,right isomerism was associated with greater complexity of cardiac malformations,with an odds ratio of 6.53,with confidence intervals from 2.2–19.3(p<0.001).The odds were slightly decreased with thoraco-abdominal disharmony,when lesions shown to carry higher risk were then found in the setting of left isomerism.Conclusion:Harmony is excellent between bronchial and appendage isomerism,but less so with the arrangement of the abdominal organs.Right isomerism in our cohort,was indicative of a sixfold increase in intracardiac complexity.When discordance was found between the systems,however,the cardiac anomalies were less typical of the anticipated findings for right vs.left isomerism of the appendages.展开更多
The reaction of 7-amino-4-methyl-2(1H)-quinolone 1 and its 6-methyl derivative 2 with Vilsmeier reagent (DMF and POCl3) afforded 7-[1-aza-2-(dimethylamino)vinyl]-4-methyl-hydroquinolin-2-one 3 and 7-[1-aza-2-(dimethyl...The reaction of 7-amino-4-methyl-2(1H)-quinolone 1 and its 6-methyl derivative 2 with Vilsmeier reagent (DMF and POCl3) afforded 7-[1-aza-2-(dimethylamino)vinyl]-4-methyl-hydroquinolin-2-one 3 and 7-[1-aza-2-(dimethylamino)vinyl]-4,6-dimethylhydroquinolin- 2-one 4, respec-tively. H-1-NMR analysis in different solvents indicated that isomerism occurred due to hindered rotation around the (CH3)(2)N-C:N o -bond. The rotational energy barrier of 3 was calculated.展开更多
One-photon absorption and two-photon absorption（TPA） properties of three tris（picolyl）amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polar...One-photon absorption and two-photon absorption（TPA） properties of three tris（picolyl）amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polarizable continuum model.The different isomer and coordination geometry of each probe are taken into account. Special emphasis is placed on the effects of isomerism and the coordination mode on the optical properties. The intra-molecular charge transfer（ICT）properties are specified by natural bond orbital charge analysis. It is shown that the isomerism has non-negligible effects on TPA properties of free ligands. It is found that both the TPA wavelength and the cross section are highly dependent on the coordination mode. When the zinc ion connects with the picolyl unit in the middle of a ligand, the zinc complex has a large TPA intensity in a long wavelength range due to the increased ICT mechanism.展开更多
The influence of rotational isomerism on the two-photon absorption （TPA） of FTC chromophores has been investi- gated using the quadratic response theory with the B3LYP functional. Eight rotamers induced by three rot...The influence of rotational isomerism on the two-photon absorption （TPA） of FTC chromophores has been investi- gated using the quadratic response theory with the B3LYP functional. Eight rotamers induced by three rotatable single bonds in the molecule are fully optimized, and it is found that their conformational energies are nearly degenerate. Our calculations demonstrate that rotational isomerism has an important effect on the TPA cross sections. For a certain rotamer, the maximum TPA cross section is enhanced significantly. In addition, in the longer wavelength region, the rotational isomerism could lead to a large shift of the TPA position.展开更多
BACKGROUND Necrotizing enterocolitis(NEC)is a multifactorial disease that predominantly affects premature neonates.Intestinal dysbiosis plays a critical role in NEC pathogenesis in premature neonates.The main risk fac...BACKGROUND Necrotizing enterocolitis(NEC)is a multifactorial disease that predominantly affects premature neonates.Intestinal dysbiosis plays a critical role in NEC pathogenesis in premature neonates.The main risk factor for NEC in term infants is mesenteric hypoperfusion associated with ductaldependent congenital heart disease(CHD)that eventually leads to intestinal ischemia.The incidence of NEC in neonates with critical CHD is 6.8%-13%.However,the role of the intestinal microbiome in NEC pathogenesis in infants with ductal-dependent CHD remains unclear.CASE SUMMARY A male term neonate with right atrial isomerism underwent modified Blalock-Taussig shunt placement on the 14^(th)day of life and had persistent mesenteric hypoperfusion after surgery.The patient had episodes of NEC stageⅡA on the 1^(st)and 28^(th)days after cardiac surgery.Fecal microbial composition was analyzed before and after cardiac surgery by sequencing region V4 of the 16S rRNA gene.Before surgery,species belonging to genera Veillonella and Clostridia and class Gammaproteobacteria were detected,Bifidobacteriaceae showed a low abundance.The first NEC episode was associated with postoperative hemodynamic instability,intestinal ischemiareperfusion injury during cardiopulmonary bypass,and a high abundance of Clostridium paraputrificum(Clostridium sensu stricto I)(56.1%).Antibacterial therapy after the first NEC episode resulted in increased abundance of Gammaproteobacteria,decreased abundance of Firmicutes,and low alpha diversity.These changes in the microbial composition promoted the growth of Clostridium sensu strictoⅠ(72.0%)before the second NEC episode.CONCLUSION A high abundance of Clostridium sensu strictoⅠand mesenteric hypoperfusion may have contributed to NEC in the present case.展开更多
Hierarchical assembly provides a rational procedure to acquire complex supramolecular architectures from basic building blocks.In this work,a novel kind of double-stranded polyrotaxane motif was reported by Ag^(+)-dir...Hierarchical assembly provides a rational procedure to acquire complex supramolecular architectures from basic building blocks.In this work,a novel kind of double-stranded polyrotaxane motif was reported by Ag^(+)-directed coordination-driven assembly following the preassembly of a four-connected pseudorotaxane(cpb)_(2)-CB8 linker.Moreover,supramolecular isomerism is observed in crystalline compounds based on double-stranded polyrotaxane motifs due to differences in lattice stacking mode.Interestingly,the resultant supramolecular isomers,cross-Ag-DSP-1 and para-Ag-DSP-1,show dual thermoand anion-responsiveness.Benefiting from high crystallinity of these coordination assemblies,a combination of characterization techniques,especially X-ray diffraction,was used to unveil precise molecular mechanisms related to the inherent dynamic behavior of these assemblies,which can be attributed to remarkable lattice rearrangement and crystal transformations as temperature increases or after anion exchange,reflecting the adaptive adjustment ability of these supramolecular architectures in response to external stimuli.Based on the anion exchange capability,these two supramolecular materials show fast removal kinetics and high sorption capacity for perrhenate(ReO_(4)^(-))anion,a surrogate of radioactive pertechnetate(TcO_(4)^(-))in nuclear waste eluents.This work provides a feasible way to supramolecular assemblies with customized structures and stimuli-responsiveness,and is helpful to design and synthesize more functional supramolecular systems with complex structures and tailored functions.展开更多
Crystalline materials with diastereomerism serve as ideal prototypes for investigating the influence of coordination environments on chemophysical properties.In this study,we synthesized a pair of axial-equatorial iso...Crystalline materials with diastereomerism serve as ideal prototypes for investigating the influence of coordination environments on chemophysical properties.In this study,we synthesized a pair of axial-equatorial isomers[Co(Ⅱ)(HB(tim^(tBu))_(3))(cis-dppen)](BF_(4))·solv([HB(tim^(tBu))_(3)]^(-)=hydrotris(3-tertbutyl-2-thioxoimidazol-1-yl)borate;cis-dppen=cis-1,2-bis(diphenylphosphino)ethene;solv=0.5THF·2H_(2)O and 2H_(2)O for ax-CoHS_(2)P_(2) and eq-CoHS2P2,respectively),by varying the crystallization temperatures.Despite both diastereoisomers adopting distorted square pyramidal geometries,the bidentate cis-dppen ligand chelates to the central Co(Ⅱ)either in an axial-equatorial or equatorial-equatorial manner,with a boron-hydrogen binding to the metal center.Magnetic studies reveal differences in g-values between these axial-equatorial isomers.X-band electron paramagnetic resonance spectra suggest rapid equilibrium and potential conformational interconversion in response to temperature changes in solution.Magnetic measurements indicate field-induced slow relaxation of magnetization in this low-spin S=1/2 system,with spin-lattice relaxations dominated by Raman and quantum tunneling of magnetization mechanisms due to the absence of thermally populated excited states.展开更多
Chiral luminescent materials with multiple functions are critically significant for multimodal anti-counterfeiting systems and information encryption,but the design strategy still faces challenges.Herein,the(R-)/(S-)-...Chiral luminescent materials with multiple functions are critically significant for multimodal anti-counterfeiting systems and information encryption,but the design strategy still faces challenges.Herein,the(R-)/(S-)-QPPTZ with aggregate conformational isomerism is ingeniously designed and synthesized,exhibiting diverse photophysical properties in poly(methyl methacrylate) matrix.Quasi-equatorial(eq) conformation with highly twisted configuration exhibits enhanced intramolecular charge transfer,which leads to shorter excitation but longer emission wavelengths.The bent configuration of the quasi-axial(ax)conformation confers inverse excitation and emission behaviors.Meanwhile,the transition characters of excited states are also manipulated by the conformational configuration,in which the intersystem crossing(ISC) is effectively facilitated,assisting in the generation of triplet excitons and enabling photoactivated phosphorescence.Multiple functionalities,including excitationdependent emission,photoactivated room-temperature phosphorescence(RTP),and circularly polarized luminescence(CPL),are simultaneously realized within the single-molecule-based system.Finally,a four-dimensional(4-D) anti-counterfeiting label is successfully demonstrated.This work not only advances the understanding of influences of molecular conformation on the molecular properties but also presents a promising strategy for multimodal anti-counterfeiting.展开更多
Millisecond isomers were recently observed in ^(213,215)Tl.These two isomers can be interpreted by the π 0h 11/2- single-proton-hole states.The 11/2−states in Tl isotopes decrease in energy when neutrons are added to...Millisecond isomers were recently observed in ^(213,215)Tl.These two isomers can be interpreted by the π 0h 11/2- single-proton-hole states.The 11/2−states in Tl isotopes decrease in energy when neutrons are added to the ν0g_(9/2) orbital,as driven by the protonneutron monopole interaction.Based on the mechanism,this work investigates the isomerism in the southeastern vicinity of ^(208)Pb with an optimized shell-model effective Hamiltonian.The 11/2−isomericγ-decay half-lives are predicted to be longer in more neutron-rich nuclei,potentially exceeding theβ-decay half-lives.In this way,βdecay may predominantly occur in the 11/2−states,which are crucial for understanding the N=126 waiting points and the A=195 peak.展开更多
The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nu...The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nucleon force,the valence-space effective Hamiltonian was derived using the ab initio many-body perturbation theory named Q-box folded diagrams.The effective operators of electromagnetic operators andβ-decay were obtained using ■-box folded diagrams.With the effective Hamiltonian and operators,we studied the properties of the isomers,gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in,showing the reliability of the ab initio calculations.展开更多
An isomerism strategy was employed to develop single,end‐group bromine-substituted non‐fullerene two isomeric acceptors,2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e...An isomerism strategy was employed to develop single,end‐group bromine-substituted non‐fullerene two isomeric acceptors,2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2,"3′′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(4-bromo-3-oxo-2,3-dihydro-1H-inden-1-ylidene)dimalononitrile(BTIC-2Br-β)and 2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2,"3′′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5-bromo-3-oxo-2,3-dihydro-1Hinden-1-ylidene)dimalononitrile(BTIC-2Br-γ).展开更多
The polymerization with positional isomerism has been theoretically studied by means ofthe nonsteady-state kinetic method. The distribution function of head-to-tail sequence, theexpressions of the concentrations of he...The polymerization with positional isomerism has been theoretically studied by means ofthe nonsteady-state kinetic method. The distribution function of head-to-tail sequence, theexpressions of the concentrations of head-to-head and tail-to- tail enchainments, and variousdyad and triad fractions have been rigorously derived on the basis of the reaction scheme.Finally, the relationships between the microstructural parameters of the resultant polymerand the polymerization conditions have been established, so that the microstructure of thepolymer with positional isomerism can be predicted from the polymerization conditions. In thecase of the reaction time being long enough, the expressions of dyad and triad fractionsgiven in this paper are simplified into those derived from the probability method.展开更多
Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the k...Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.展开更多
The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen f...The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen fibers were used to anchor Zr^(4+),and a highly dispersed ZrO_(2)-nitrogen-doped carbon(ZrO_(2)-NC)composite catalyst was subsequently fabricated by calcination.For the catalytic glucose-to-fructose isomerization over ZrO_(2)-NC,fructose was obtained in 41.3%yield and 85.3%selectivity in a water-acetone solvent at 120℃ for 10 min.The electron-deficient environment of ZrO_(2)surface during charge transfer from ZrO_(2)-to-NC layer facilitated the preferential adsorption of glucose,which accelerated glucose isomerization and fructose desorption.The amphoteric catalyst triggered both proton transfer on the Bronsted base sites and the intramolecular hydride shift of glucose on the Lewis acid sites of ZrO_(2)-NC in the mixed solvent.The latter isomerization mechanism depended on the presence of acetone,which lowered the energy barrier and increased fructose yield.展开更多
Three-quasiparticle K-isomeric states in odd-mass N=106 isotones within the A~180 mass region were systematically investigated using configuration-constrained potential energy surface calculations.The calculations suc...Three-quasiparticle K-isomeric states in odd-mass N=106 isotones within the A~180 mass region were systematically investigated using configuration-constrained potential energy surface calculations.The calculations succes sfully reproduced the excitation energies and deformations of the known high-K isomers in nuclei from 175Tm to 181Re.For the nuclei closer to the Z=82 shell closure(^(183)Ir,^(185)Au,and^(187)Tl),predictions of the configurations of the observed and yet-to-be-observed isomers are provided.The results reveal strong shape polarization,where the three-quasiparticle states are driven to larger deformations compared to the often shape-soft or spherical ground states.A particularly rich spectrum of shape coexistence is predicted in^(187)Tl,where several high-K three-quasiparticle configurations with distinct prolate,oblate,and triaxial shapes are found to coexist at similar excitation energies.Notably,the oblate-deformed K^(π)=29/2^(+)configuration at E_(x)=1839 keV was proposed to be responsible for a long-lived isomer.This study provides a comprehensive picture of shape evolution and coexistence in high-K multi-quasiparticle states,offering valuable insights for future experimental studies.展开更多
1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(I...1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(IL),and enhancement of upper stopband rejection(Huang et al.,2021;Snyder et al.,2021;Lin et al.,2023;Zeng et al.,2023).展开更多
To establish practical,evidence-based strategies for noninvasive assessment and referral of patients with metabolic dysfunction-associated steatotic liver disease(MASLD)in Japan,we must address the urgent clinical nee...To establish practical,evidence-based strategies for noninvasive assessment and referral of patients with metabolic dysfunction-associated steatotic liver disease(MASLD)in Japan,we must address the urgent clinical need for accurate risk stratification and timely specialist intervention.A panel of 11 Japanese hepatology experts conducted a modified Delphi process to evaluate consensus recommendations regarding the use of noninvasive tests(NITs),including the fibrosis-4 index,enhanced liver fibrosis test,Mac-2-binding protein glycosylation isomer,type IV collagen 7S,cytokeratin-18 fragments,and imaging modalities such as ultrasound elastography and magnetic resonance elastography,for MASLD assessment and clinical referral.Practical algorithms were developed based on current Japanese data and panel consensus.The expert panel validated the utility of NITs as reliable tools for identifying patients with MASLD at risk for advanced fibrosis.Sequential use of NITs improved diagnostic accuracy and referral appropriateness while minimizing unnecessary specialist consultations.The proposed algorithms offer stepwise guidance for primary care physicians,supporting efficient,evidence-based decisionmaking.However,prospective longitudinal studies remain necessary for full prognostic validation of NITs in MASLD management.Noninvasive testing algorithms enable effective risk stratification and referral for MASLD in real-world Japanese practice with anticipated benefit for patient outcomes and healthcare systems.Broader adoption and further validation are warranted.展开更多
基金supported by Youth Talent Project of Scientific Research Program of Hubei Provincial Department of Education under Grant Q20241809Doctoral Scientific Research Foundation of Hubei University of Automotive Technology under Grant 202404.
文摘As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays a pivotal role in MEC performance but remains challenging due to complex task topologies,conflicting objectives,and limited resources.This paper addresses high-dimensional multi-objective offloading for serial heterogeneous tasks in MEC.We jointly consider task heterogeneity,high-dimensional objectives,and flexible resource scheduling,modeling the problem as a Many-objective optimization.To solve it,we propose a flexible framework integrating an improved cooperative co-evolutionary algorithm based on decomposition(MOCC/D)and a flexible scheduling strategy.Experimental results on benchmark functions and simulation scenarios show that the proposed method outperforms existing approaches in both convergence and solution quality.
基金financially supported by the National Science Foundation of China(62474142)Natural Science Foundation of Shandong Province(No.ZR2024YQ070)。
文摘Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses.However,how these groups synergistically affect the enhancement beyond passivation is still unclear.Specifically,isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives.Here,we report two isomeric carbazolyl bisphosphonate additives,2,7-Cz BP and 3,6-Cz BP.The isomerism effect on passivation and charge transport process was studied.The two molecules have similar passivation effects through multiple interactions,e.g.,P=O···Pb,P=O···H–N and N–H···I.2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport.Power conversion efficiencies(PCEs)of 25.88%and 21.04%were achieved for 0.09 cm^(2)devices and 14 cm^(2)modules after 2,7-Cz BP treatment,respectively.The devices exhibited enhanced operational stability maintaining 95%of initial PCE after 1000 h of continuous maximum power point tracking.This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives,which paves the way for innovation of next-generation multifunctional aromatic additives.
基金ACKNOWLEDGMENTS This work was supported by Young Scientists Fund of the National Natural Science Foundation of China （No.10904085）.
文摘Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-（4-N,N-di（2-acetoxyethyl）-amino）-phenylene-（3,4-dibutyl）-thien-5]-E-vinylg-5,5-dimethyl-2,5-dihydrofuran （FTC） in a few solvents have been studied using the time-dependent density functional theory in combination with the polarizable continuum model. It is shown that the maximum absorption peaks of the ro-tamers have difference of nearly 30 nm both in vacuum and in solutions. The population of the rotamers changes a lot in different solvents. Based on the geometries optimized by Hartree-Fock method, the Maxwell-Boltzmann averaged absorption has been calculated and the maximum absorption peak is in good agreement with experiment. It indicates that the bond length alternation can have an important effect on the optical spectra.
文摘Aims:Evidence is emerging that,in the setting of isomerism,the atrial and bronchial arrangement are not always concordant,nor are these patterns always harmonious with the arrangement of the abdominal organs.We aimed to evaluate the concordance between these features in a cohort of patients with cardiac malformations in the setting of known isomerism,seeking to determine whether it was feasible to assess complexity on this basis,in this regard taking note of the potential value of bronchial as opposed to appendage morphology.Methods and Results:We studied 78 patients known to have isomerism of the bronchuses,43 with right and 35 with left isomerism.Appendage anatomy could be determined in 49 cases(63%),all but one of these being concordant with bronchial anatomy.When assessing abdominal features,in only 59 cases(76%)was splenic morphology in keeping with the thoracic findings.As expected,right isomerism was associated with greater complexity of cardiac malformations,with an odds ratio of 6.53,with confidence intervals from 2.2–19.3(p<0.001).The odds were slightly decreased with thoraco-abdominal disharmony,when lesions shown to carry higher risk were then found in the setting of left isomerism.Conclusion:Harmony is excellent between bronchial and appendage isomerism,but less so with the arrangement of the abdominal organs.Right isomerism in our cohort,was indicative of a sixfold increase in intracardiac complexity.When discordance was found between the systems,however,the cardiac anomalies were less typical of the anticipated findings for right vs.left isomerism of the appendages.
文摘The reaction of 7-amino-4-methyl-2(1H)-quinolone 1 and its 6-methyl derivative 2 with Vilsmeier reagent (DMF and POCl3) afforded 7-[1-aza-2-(dimethylamino)vinyl]-4-methyl-hydroquinolin-2-one 3 and 7-[1-aza-2-(dimethylamino)vinyl]-4,6-dimethylhydroquinolin- 2-one 4, respec-tively. H-1-NMR analysis in different solvents indicated that isomerism occurred due to hindered rotation around the (CH3)(2)N-C:N o -bond. The rotational energy barrier of 3 was calculated.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM026)the Taishan Scholar Project of Shandong Province,China
文摘One-photon absorption and two-photon absorption（TPA） properties of three tris（picolyl）amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polarizable continuum model.The different isomer and coordination geometry of each probe are taken into account. Special emphasis is placed on the effects of isomerism and the coordination mode on the optical properties. The intra-molecular charge transfer（ICT）properties are specified by natural bond orbital charge analysis. It is shown that the isomerism has non-negligible effects on TPA properties of free ligands. It is found that both the TPA wavelength and the cross section are highly dependent on the coordination mode. When the zinc ion connects with the picolyl unit in the middle of a ligand, the zinc complex has a large TPA intensity in a long wavelength range due to the increased ICT mechanism.
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 10904085)
文摘The influence of rotational isomerism on the two-photon absorption （TPA） of FTC chromophores has been investi- gated using the quadratic response theory with the B3LYP functional. Eight rotamers induced by three rotatable single bonds in the molecule are fully optimized, and it is found that their conformational energies are nearly degenerate. Our calculations demonstrate that rotational isomerism has an important effect on the TPA cross sections. For a certain rotamer, the maximum TPA cross section is enhanced significantly. In addition, in the longer wavelength region, the rotational isomerism could lead to a large shift of the TPA position.
基金Supported by the Russian Science Foundation,No.22-25-00484。
文摘BACKGROUND Necrotizing enterocolitis(NEC)is a multifactorial disease that predominantly affects premature neonates.Intestinal dysbiosis plays a critical role in NEC pathogenesis in premature neonates.The main risk factor for NEC in term infants is mesenteric hypoperfusion associated with ductaldependent congenital heart disease(CHD)that eventually leads to intestinal ischemia.The incidence of NEC in neonates with critical CHD is 6.8%-13%.However,the role of the intestinal microbiome in NEC pathogenesis in infants with ductal-dependent CHD remains unclear.CASE SUMMARY A male term neonate with right atrial isomerism underwent modified Blalock-Taussig shunt placement on the 14^(th)day of life and had persistent mesenteric hypoperfusion after surgery.The patient had episodes of NEC stageⅡA on the 1^(st)and 28^(th)days after cardiac surgery.Fecal microbial composition was analyzed before and after cardiac surgery by sequencing region V4 of the 16S rRNA gene.Before surgery,species belonging to genera Veillonella and Clostridia and class Gammaproteobacteria were detected,Bifidobacteriaceae showed a low abundance.The first NEC episode was associated with postoperative hemodynamic instability,intestinal ischemiareperfusion injury during cardiopulmonary bypass,and a high abundance of Clostridium paraputrificum(Clostridium sensu stricto I)(56.1%).Antibacterial therapy after the first NEC episode resulted in increased abundance of Gammaproteobacteria,decreased abundance of Firmicutes,and low alpha diversity.These changes in the microbial composition promoted the growth of Clostridium sensu strictoⅠ(72.0%)before the second NEC episode.CONCLUSION A high abundance of Clostridium sensu strictoⅠand mesenteric hypoperfusion may have contributed to NEC in the present case.
基金the financial support from the National Natural Science Foundation of China(Nos.22122609,22076186,51472224 and U20B2019)。
文摘Hierarchical assembly provides a rational procedure to acquire complex supramolecular architectures from basic building blocks.In this work,a novel kind of double-stranded polyrotaxane motif was reported by Ag^(+)-directed coordination-driven assembly following the preassembly of a four-connected pseudorotaxane(cpb)_(2)-CB8 linker.Moreover,supramolecular isomerism is observed in crystalline compounds based on double-stranded polyrotaxane motifs due to differences in lattice stacking mode.Interestingly,the resultant supramolecular isomers,cross-Ag-DSP-1 and para-Ag-DSP-1,show dual thermoand anion-responsiveness.Benefiting from high crystallinity of these coordination assemblies,a combination of characterization techniques,especially X-ray diffraction,was used to unveil precise molecular mechanisms related to the inherent dynamic behavior of these assemblies,which can be attributed to remarkable lattice rearrangement and crystal transformations as temperature increases or after anion exchange,reflecting the adaptive adjustment ability of these supramolecular architectures in response to external stimuli.Based on the anion exchange capability,these two supramolecular materials show fast removal kinetics and high sorption capacity for perrhenate(ReO_(4)^(-))anion,a surrogate of radioactive pertechnetate(TcO_(4)^(-))in nuclear waste eluents.This work provides a feasible way to supramolecular assemblies with customized structures and stimuli-responsiveness,and is helpful to design and synthesize more functional supramolecular systems with complex structures and tailored functions.
基金supported by the NSFC(Grant Nos.22475246,22105230 and 21821003)the Fundamental Research Funds for the Central UniversitiesSun Yat-sen University(24xkjc003 and 24qnpy051).
文摘Crystalline materials with diastereomerism serve as ideal prototypes for investigating the influence of coordination environments on chemophysical properties.In this study,we synthesized a pair of axial-equatorial isomers[Co(Ⅱ)(HB(tim^(tBu))_(3))(cis-dppen)](BF_(4))·solv([HB(tim^(tBu))_(3)]^(-)=hydrotris(3-tertbutyl-2-thioxoimidazol-1-yl)borate;cis-dppen=cis-1,2-bis(diphenylphosphino)ethene;solv=0.5THF·2H_(2)O and 2H_(2)O for ax-CoHS_(2)P_(2) and eq-CoHS2P2,respectively),by varying the crystallization temperatures.Despite both diastereoisomers adopting distorted square pyramidal geometries,the bidentate cis-dppen ligand chelates to the central Co(Ⅱ)either in an axial-equatorial or equatorial-equatorial manner,with a boron-hydrogen binding to the metal center.Magnetic studies reveal differences in g-values between these axial-equatorial isomers.X-band electron paramagnetic resonance spectra suggest rapid equilibrium and potential conformational interconversion in response to temperature changes in solution.Magnetic measurements indicate field-induced slow relaxation of magnetization in this low-spin S=1/2 system,with spin-lattice relaxations dominated by Raman and quantum tunneling of magnetization mechanisms due to the absence of thermally populated excited states.
基金supported by the National Key Research and Development Program of China (2023YFB3810001)the National Natural Science Foundation of China (52333007,52273197,62205384)+1 种基金the Science Technology Innovation Commission of Shenzhen Municipality (KQTD20210811090142053,GJHZ20210705141810031)the Innovation and Technology Commission (ITC-CNERC14SC01)。
文摘Chiral luminescent materials with multiple functions are critically significant for multimodal anti-counterfeiting systems and information encryption,but the design strategy still faces challenges.Herein,the(R-)/(S-)-QPPTZ with aggregate conformational isomerism is ingeniously designed and synthesized,exhibiting diverse photophysical properties in poly(methyl methacrylate) matrix.Quasi-equatorial(eq) conformation with highly twisted configuration exhibits enhanced intramolecular charge transfer,which leads to shorter excitation but longer emission wavelengths.The bent configuration of the quasi-axial(ax)conformation confers inverse excitation and emission behaviors.Meanwhile,the transition characters of excited states are also manipulated by the conformational configuration,in which the intersystem crossing(ISC) is effectively facilitated,assisting in the generation of triplet excitons and enabling photoactivated phosphorescence.Multiple functionalities,including excitationdependent emission,photoactivated room-temperature phosphorescence(RTP),and circularly polarized luminescence(CPL),are simultaneously realized within the single-molecule-based system.Finally,a four-dimensional(4-D) anti-counterfeiting label is successfully demonstrated.This work not only advances the understanding of influences of molecular conformation on the molecular properties but also presents a promising strategy for multimodal anti-counterfeiting.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research (Grant No. 2021B0301030006)the National Natural Science Foundation of China (Grant Nos. 12475129, 12405144, and 12305129)+2 种基金the International Atomic Energy Agency Coordinatated Research Project F41034 (Grant No. 28649)the Computational Resources from Sun Yat-sen University and Fudan Universitythe National Supercomputer Center in Guangzhou
文摘Millisecond isomers were recently observed in ^(213,215)Tl.These two isomers can be interpreted by the π 0h 11/2- single-proton-hole states.The 11/2−states in Tl isotopes decrease in energy when neutrons are added to the ν0g_(9/2) orbital,as driven by the protonneutron monopole interaction.Based on the mechanism,this work investigates the isomerism in the southeastern vicinity of ^(208)Pb with an optimized shell-model effective Hamiltonian.The 11/2−isomericγ-decay half-lives are predicted to be longer in more neutron-rich nuclei,potentially exceeding theβ-decay half-lives.In this way,βdecay may predominantly occur in the 11/2−states,which are crucial for understanding the N=126 waiting points and the A=195 peak.
基金supported by the National Key R&D Program of China under Grant Nos.2024YFA1610900 and 2023YFA1606401the National Natural Science Foundation of China under Grant Nos.12335007 and 12035001。
文摘The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nucleon force,the valence-space effective Hamiltonian was derived using the ab initio many-body perturbation theory named Q-box folded diagrams.The effective operators of electromagnetic operators andβ-decay were obtained using ■-box folded diagrams.With the effective Hamiltonian and operators,we studied the properties of the isomers,gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in,showing the reliability of the ab initio calculations.
基金supported by the National Natural Science Foundation of China(nos.51773087,21733005,and 21975115)Shenzhen Fundamental Research Program(nos.JCYJ20170817111214740,JCYJ20180302180238419,and KQJSCX20180319114442157),and Shenzhen Nobel Prize Scientists Laboratory Project(no.C17213101)and the Guangdong Innovative and Entrepreneurial Research Team Program under contract no.2016ZT06G587.
文摘An isomerism strategy was employed to develop single,end‐group bromine-substituted non‐fullerene two isomeric acceptors,2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2,"3′′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(4-bromo-3-oxo-2,3-dihydro-1H-inden-1-ylidene)dimalononitrile(BTIC-2Br-β)and 2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2,"3′′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5-bromo-3-oxo-2,3-dihydro-1Hinden-1-ylidene)dimalononitrile(BTIC-2Br-γ).
文摘The polymerization with positional isomerism has been theoretically studied by means ofthe nonsteady-state kinetic method. The distribution function of head-to-tail sequence, theexpressions of the concentrations of head-to-head and tail-to- tail enchainments, and variousdyad and triad fractions have been rigorously derived on the basis of the reaction scheme.Finally, the relationships between the microstructural parameters of the resultant polymerand the polymerization conditions have been established, so that the microstructure of thepolymer with positional isomerism can be predicted from the polymerization conditions. In thecase of the reaction time being long enough, the expressions of dyad and triad fractionsgiven in this paper are simplified into those derived from the probability method.
基金Bureau of Science and Information of Guangzhou under grant 2024A04J3254the National Key Research and Development Program of China under grant 2024YFE0214900+2 种基金the National Natural Science Foundation of China under grant 32272341,he National Key Research and Development Program of China under grant 2023YFD2100401the Opening Project of Hubei Key Laboratory of Lipid Chemistry and Nutrition under grant 202401,are gratefully acknowledged.
文摘Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.
基金supported by National Natural Science Foundation of China(22478265)Sichuan Science and Technology Program(2024NSFSC0222)the Fundamental Research Funds for the Central Universities.We are thankful to Hui Wang at the Analytical&Testing Center,Sichuan University,for assisting with SEM characterization.We appreciate Dr.Xiu He and Dr.Ying Song from the College of Biomass Science and Engineering of Sichuan University for helping with experimental.
文摘The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen fibers were used to anchor Zr^(4+),and a highly dispersed ZrO_(2)-nitrogen-doped carbon(ZrO_(2)-NC)composite catalyst was subsequently fabricated by calcination.For the catalytic glucose-to-fructose isomerization over ZrO_(2)-NC,fructose was obtained in 41.3%yield and 85.3%selectivity in a water-acetone solvent at 120℃ for 10 min.The electron-deficient environment of ZrO_(2)surface during charge transfer from ZrO_(2)-to-NC layer facilitated the preferential adsorption of glucose,which accelerated glucose isomerization and fructose desorption.The amphoteric catalyst triggered both proton transfer on the Bronsted base sites and the intramolecular hydride shift of glucose on the Lewis acid sites of ZrO_(2)-NC in the mixed solvent.The latter isomerization mechanism depended on the presence of acetone,which lowered the energy barrier and increased fructose yield.
基金supported by the National Natural Science Foundation of China(No.12275369)。
文摘Three-quasiparticle K-isomeric states in odd-mass N=106 isotones within the A~180 mass region were systematically investigated using configuration-constrained potential energy surface calculations.The calculations succes sfully reproduced the excitation energies and deformations of the known high-K isomers in nuclei from 175Tm to 181Re.For the nuclei closer to the Z=82 shell closure(^(183)Ir,^(185)Au,and^(187)Tl),predictions of the configurations of the observed and yet-to-be-observed isomers are provided.The results reveal strong shape polarization,where the three-quasiparticle states are driven to larger deformations compared to the often shape-soft or spherical ground states.A particularly rich spectrum of shape coexistence is predicted in^(187)Tl,where several high-K three-quasiparticle configurations with distinct prolate,oblate,and triaxial shapes are found to coexist at similar excitation energies.Notably,the oblate-deformed K^(π)=29/2^(+)configuration at E_(x)=1839 keV was proposed to be responsible for a long-lived isomer.This study provides a comprehensive picture of shape evolution and coexistence in high-K multi-quasiparticle states,offering valuable insights for future experimental studies.
基金supported by the National Natural Science Foundation of China(No.62371263)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCK25_1995).
文摘1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(IL),and enhancement of upper stopband rejection(Huang et al.,2021;Snyder et al.,2021;Lin et al.,2023;Zeng et al.,2023).
基金Supported by Japan Society for the Promotion of Science KAKENHI,No.25K11274.
文摘To establish practical,evidence-based strategies for noninvasive assessment and referral of patients with metabolic dysfunction-associated steatotic liver disease(MASLD)in Japan,we must address the urgent clinical need for accurate risk stratification and timely specialist intervention.A panel of 11 Japanese hepatology experts conducted a modified Delphi process to evaluate consensus recommendations regarding the use of noninvasive tests(NITs),including the fibrosis-4 index,enhanced liver fibrosis test,Mac-2-binding protein glycosylation isomer,type IV collagen 7S,cytokeratin-18 fragments,and imaging modalities such as ultrasound elastography and magnetic resonance elastography,for MASLD assessment and clinical referral.Practical algorithms were developed based on current Japanese data and panel consensus.The expert panel validated the utility of NITs as reliable tools for identifying patients with MASLD at risk for advanced fibrosis.Sequential use of NITs improved diagnostic accuracy and referral appropriateness while minimizing unnecessary specialist consultations.The proposed algorithms offer stepwise guidance for primary care physicians,supporting efficient,evidence-based decisionmaking.However,prospective longitudinal studies remain necessary for full prognostic validation of NITs in MASLD management.Noninvasive testing algorithms enable effective risk stratification and referral for MASLD in real-world Japanese practice with anticipated benefit for patient outcomes and healthcare systems.Broader adoption and further validation are warranted.
