An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system...An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system based on intergeneric conjugation was developed in Streptomyces rimosus M527,a bacterial strain which exhibits strong antagonistic activity against a broad range of plant-pathogenic fungi.Some experimental parameters involved in this procedure were optimized,including the conjugative media,ratio of donor to recipient,heat shock temperature,and incubation time of mixed culture.Under the optimal conditions,a maximal conjugation frequency of 3.05^10-5 per recipie nt was obtai ned.Subseque ntly,based on the above developed and optimized tran sformati on system,the synthetic promoters SPL-21 and SPL-57,a native promoter potrB,and a constitutive promoter permE commonly used for gene expression in streptomycetes were selected and their activity was analyzed using gusA as a reporter gene in S.rimosus M527.Among the four tested promoters,SPL-21 exhibited the strongest expression activity and gave rise to a 2.2-fold increase in p-glucuronidase(GUS)activity compared with the control promoter permE.Promoter SPL-57 showed activity comparable to that of permE.Promoter potrB,which showed the lowest activity,showed a 50%decrease in GUS activity compared with the control permE.The transformation system developed in this study and the tested promotors provide a basis for the further modification of S.rimosus M527.展开更多
In this paper, we consider 2 × 2 non-cooperative elliptic system involving Laplace operator defined on bounded, continuous and strictly Lipschitz domain of Rn. First we prove the existence and uniqueness for the ...In this paper, we consider 2 × 2 non-cooperative elliptic system involving Laplace operator defined on bounded, continuous and strictly Lipschitz domain of Rn. First we prove the existence and uniqueness for the state of the system under conjugation conditions;then we discuss the existence of the optimal control of boundary type with Neumann conditions, and we find the set of equations and inequalities that characterize it.展开更多
Wearable biosensors have received great interest as patient-friendly diagnostic technologies because of their high flexibility and conformability.The growing research and utilization of novel materials in designing we...Wearable biosensors have received great interest as patient-friendly diagnostic technologies because of their high flexibility and conformability.The growing research and utilization of novel materials in designing wearable biosensors have accelerated the development of point-of-care sensing platforms and implantable biomedical devices in human health care.Among numerous potential materials,conjugated polymers(CPs)are emerging as ideal choices for constructing high-performance wearable biosensors because of their outstanding conductive and mechanical properties.Recently,CPs have been extensively incorporated into various wearable biosensors to monitor a range of target biomolecules.However,fabricating highly reliable CP-based wearable biosensors for practical applications remains a significant challenge,necessitating novel developmental strategies for enhancing the viability of such biosensors.Accordingly,this review aims to provide consolidated scientific evidence by summarizing and evaluating recent studies focused on designing and fabricating CP-based wearable biosensors,thereby facilitating future research.Emphasizing the superior properties and benefits of CPs,this review aims to clarify their potential applicability within this field.Furthermore,the fundamentals and main components of CP-based wearable biosensors and their sensing mechanisms are discussed in detail.The recent advancements in CP nanostructures and hybridizations for improved sensing performance,along with recent innovations in next-generation wearable biosensors are highlighted.CPbased wearable biosensors have been—and will continue to be—an ideal platform for developing effective and user-friendly diagnostic technologies for human health monitoring.展开更多
Understanding the quantum effect in the cross-conjugated system is of fundamental significance in molecular electronics.In this study,four molecules Xa-O,Xa,BP and BP-O were synthesized to investigate the destructive ...Understanding the quantum effect in the cross-conjugated system is of fundamental significance in molecular electronics.In this study,four molecules Xa-O,Xa,BP and BP-O were synthesized to investigate the destructive quantum interference(DQI)of a carbonyl bridge.The single-molecule conductance measured by the scanning tunneling microscope break junction(STM-BJ)technique demonstrates an increase in the conductance from molecule BP-O to molecule Xa-O as the cross-conjugated system is extended.Theoretical calculations show that the explicit DQI feature is presented in BP-O but absent in Xa-O,which indicates the removal of DQI in the restrained structures and results in the conductance enhancement in Xa-O.展开更多
The existence and uniqueness of the state for 2 × 2 Dirichlet cooperative elliptic systems under conjugation conditions are proved using Lax-Milgram lemma, then the boundary control for these systems is discussed...The existence and uniqueness of the state for 2 × 2 Dirichlet cooperative elliptic systems under conjugation conditions are proved using Lax-Milgram lemma, then the boundary control for these systems is discussed. The set of equations and inequalities that characterizes this boundary control is found by theory of Lions, Sergienko and Deineka. The problem for cooperative Neumann elliptic systems under conjugation conditions is also considered. Finally, the problem for <em>n</em> × <em>n</em> cooperative elliptic systems under conjugation conditions is established.展开更多
Ciliates are eukaryotic unicellular organisms with complex morphology and developmental processes,including asexual and sexual processes.Conjugation is a form of sexual process that renews genetic materials.However,vi...Ciliates are eukaryotic unicellular organisms with complex morphology and developmental processes,including asexual and sexual processes.Conjugation is a form of sexual process that renews genetic materials.However,visualizing conjugation in ciliates is a challenge due to the complexity and dynamics of the process,while traditional staining methods are often insufficient for the research.This study introduces a new method for visualizing developmental progression in the nuclei during conjugation using Hoechst33342 staining.It describes how to proceed from cell culture,conjugation induction and synchronization,staining preparation,and observation to statistical analysis.The combination of fluorescent staining with the‘volume-fixing'technique eliminates the fixation and dehydration steps,thus reducing the overall operation time to just 20 minutes.This method offers several advantages over traditional staining techniques for studying the nuclei during conjugation.It improves image quality and workflow efficiency and enables real-time observation of live cell states.Potential solutions to challenges that may arise during experimental procedures are introduced and references and guidelines for cytological research are provided in this paper.展开更多
Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs...Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs)are constructed through co-entrapping glucose oxidase(GOx)and horseradish peroxidase(HRP),in which hydrogen peroxide(H_(2)O_(2)) is the intermediate product.The interplay of low-resistance mass transfer pathway and appropriate pore wall-H_(2)O_(2) interactions facilitates the directed transfer of H_(2)O_(2),resulting in 2.4-fold and 5.0-fold elevation in catalytic activ-ity compared to free ECSs and separated ECSs,respectively.The substrate channeling effect could be regulated by altering the mass ratio of GOx to HRP.Besides,I-ECSs demonstrate excellent stabili-ties in harsh environments and multiple recycling.展开更多
Cell-free systems significantly improve network capacity by enabling joint user service without cell boundaries,eliminating intercell interference.However,to satisfy further capacity demands,it leads to high-cost prob...Cell-free systems significantly improve network capacity by enabling joint user service without cell boundaries,eliminating intercell interference.However,to satisfy further capacity demands,it leads to high-cost problems of both hardware and power consumption.In this paper,we investigate multiple reconfigurable intelligent surfaces(RISs)aided cell-free systems where RISs are introduced to improve spectrum efficiency in an energy-efficient way.To overcome the centralized high complexity and avoid frequent information exchanges,a cooperative distributed beamforming design is proposed to maximize the weighted sum-rate performance.In particular,the alternating optimization method is utilized with the distributed closed-form solution of active beamforming being derived locally at access points,and phase shifts are obtained centrally based on the Riemannian conjugate gradient(RCG)manifold method.Simulation results verify the effectiveness of the proposed design whose performance is comparable to the centralized scheme and show great superiority of the RISs-aided system over the conventional cellular and cell-free system.展开更多
During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century...During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century. Here we report on new details concerning the conjugation of P. caudatum through the staining of conjugating ceils with protargol, carbol fuchsin solution, Hoechst 33342 and immunofluorescence labeling with monoclonal antibody of anti-a tubulin. 1) The crescent nucleus is a characteristic of the meiotic prophase of P. caudatum, has an unstained area. We stained this area with protargol, which was separated from the chromatin area and was not detected by the other stainings. 2) In regards to the four meiotic products, it has long been considered that only one product enters the paroral cone region (PC) and survives after meiosis. However, our protargol and immunofluorescence labeling results indicated that PC entrance of the meiotic product happened before the completion of meiosis instead of after. 3) In our previous study, protargol staining indicated the presence of a swollen structure around the central part of the "U" and "V" shaped spindles connecting the two types of prospective pronuclei. However, immunofluorescence labeling with anti-a tubulin antibodies gave a different image from protargol. All these observations form the basis for further studies of their molecular mechanisms.展开更多
After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating bounda...After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating boundaries;while the stationary pronuclei are located beside the migratory pronuclei.To date,however,it is not clear what causes this close side-by-side localization between migratory and stationary pronuclei.In the current study,immunofluorescence staining with monoclonal antibody of anti-α tubulin indicated that "U" or "V" shaped spindles connected the migratory and stationary pronuclei during the third prezygotic division.This observation accounts for the close localization between these two types of pronuclei.展开更多
Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors c...Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.展开更多
Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and su...Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and sufficient conditions for the existence of and the expressions for the msc solutions and the ssd solutions are obtained for the system.展开更多
Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of ...Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of a large conjugate strike-slip fault system from the intracratonic Tarim Basin, NW China. Within our study area, "X" type NE and NW trending faults occur within Cambrian- Ordovician carbonates. The dihedral angles of these conjugate faults have narrow ranges, 19~ to 62~ in the Cambrian and 26~ to 51~ in the Ordovician, and their modes are 42~ and 44~ respectively. These data are significantly different from the ~60~ predicted by the Coulomb fracture criterion. It is concluded that: (1) The dihedral angles of the conjugate faults were not controlled by confining pressure, which was low and associated with shallow burial; (2) As dihedral angles were not controlled by pressure they can be used to determine the shortening direction during faulting; (3) Sequential slip may have played an important role in forming conjugate fault intersections; (4) The conjugate fault system of the Tarim basin initiated as rhombic joints; these subsequently developed into sequentially active "X" type conjugate faults; followed by preferential development of the NW-trending faults; then reactivation of the NE trending faults. This intact rhombic conjugate fault system presents new insights into mechanisms of dihedral angle development, with particular relevance to intracratonic basins.展开更多
The initial cell search plays an important role during the process of downlink synchronization establishment between the User Equipment(UE) and the base station. In particular, the uncertainty of the synchronization s...The initial cell search plays an important role during the process of downlink synchronization establishment between the User Equipment(UE) and the base station. In particular, the uncertainty of the synchronization signals on the frequency domain and the flexibility of frame structure configuration have brought great challenges to the initial cell search for the fifth-generation(5G) new radio(NR). To solve this problem, firstly, we analyze the physical layer frame structure of 5G NR systems. Then, by focusing on the knowledge of synchronization signals, the 5G NR cell search process is designed, and the primary synchronization signal(PSS) timing synchronization algorithm is proposed, including a 5G-based coarse synchronization algorithm and conjugate symmetry-based fine synchronization algorithm. Finally, the performance of the proposed cell search algorithm in 5G NR systems is verified through the combination of Digital Signal Processing(DSP) and personal computer(PC). And the MATLAB simulation proves that the proposed algorithm has better performance than the conventional cross-correlation algorithm when a certain frequency offset exists.展开更多
BACKGROUND: Dubin-Johnson syndrome (DJS) is a rare clinical entity. We describe a case of DJS complicated by systemic lupus erythematosus (SLE). METHODS: A case of congenital hyperbilirubinemia with SLE was evaluated ...BACKGROUND: Dubin-Johnson syndrome (DJS) is a rare clinical entity. We describe a case of DJS complicated by systemic lupus erythematosus (SLE). METHODS: A case of congenital hyperbilirubinemia with SLE was evaluated systematically including review of history, physical examination for the stigmata of chronic liver disease, and other investigations. RESULT: Liver biopsy revealed a black liver with preserved architecture suggestive of DJS. CONCLUSIONS: SLE may develop in DJS. The relationship between DJS and SLE in this case is most likely a chance occurrence.展开更多
A pH-responsive conjugate based 10-hydroxycamptothecin-thiosemicarbazide-polyethene glycol 2000 (10-HCPT-hydro-PEG) nano-micelles were prepared in our previous study. In the present study, ultra-performance liquid chr...A pH-responsive conjugate based 10-hydroxycamptothecin-thiosemicarbazide-polyethene glycol 2000 (10-HCPT-hydro-PEG) nano-micelles were prepared in our previous study. In the present study, ultra-performance liquid chromatography (UPLC-MS) method is developed to investigate its pharmacokinetics and biodistribution in tumor bearing mice. The results demonstrated that the conjugate circulated for a much longer time in the blood circulation system than commercial 10-HCPT injection, and bioavailability was significantly improved compared with 10-HCPT. In vivo biodistribution study showed that the conjugate could enhance the targeting and residence time in tumor site.展开更多
The strategies that minimize the overall solution time of multiple linear systems in 3D finite element method (FEM) modeling of direct current (DC) resistivity were discussed. A global stiff matrix is assembled and st...The strategies that minimize the overall solution time of multiple linear systems in 3D finite element method (FEM) modeling of direct current (DC) resistivity were discussed. A global stiff matrix is assembled and stored in two parts separately. One part is associated with the volume integral and the other is associated with the subsurface boundary integral. The equivalent multiple linear systems with closer right-hand sides than the original systems were constructed. A recycling Krylov subspace technique was employed to solve the multiple linear systems. The solution of the seed system was used as an initial guess for the subsequent systems. The results of two numerical experiments show that the improved algorithm reduces the iterations and CPU time by almost 50%, compared with the classical preconditioned conjugate gradient method.展开更多
This paper presents an algorithm that aims to reduce the peak-to-average power ratio(PAPR) of orthogonal frequency division multiplexing(OFDM) communication systems while maintaining frequency tracking.The algorit...This paper presents an algorithm that aims to reduce the peak-to-average power ratio(PAPR) of orthogonal frequency division multiplexing(OFDM) communication systems while maintaining frequency tracking.The algorithm achieves PAPR reduction by applying the complex conjugates of the data symbol obtained from the frequency domain to cancel the phase of the data symbol.A likelihood estimator is used to obtain the sub-carrier phase error due to the residual carrier frequency offset(RCFO) using the same complex conjugates as a pilot signal.Furthermore,a joint time and frequency domain multicarrier phase locked loop(MPLL) is developed to compensate additional frequency offset.Simulation results show that this algorithm is capable of reducing PAPR without impacting the frequency tracking performance.展开更多
Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite sol...Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite solar cells(PSCs) are synthesized by facile one-step reaction in good yield over 75%. DTF unit as electron donor can enhance the electron donating ability and the fusion of benzenic ring of TPA with DTF unit may lead to reinforced intermolecular interactions in the solid state. In addition,WH-2 and WH-3 exhibit a pyramid shape containing partial planarity and quasi three-dimensionality features, which is also conducive to enhancing the π-π stacking of molecules in the solid state. The above-mentioned structural characteristics make the two HTMs have good hole mobilities. As a result,WH-2 and WH-3 obtained the high intrinsic hole mobilities of 4.69 × 10^(-4)and 2.18 × 10^(-3)cm^(2)V^(-1)s^(-1)respectively. Finally, the power conversion efficiencies(PCEs) of PSCs with WH-2 and WH-3 as cost-effective dopant-free HTMs are 15.39% and 19.22% respectively and the PCE of PSC with WH-3 is on a par with that of PSC with Li-TFSI/t-BP doped Spiro-OMe TAD(19.67%).展开更多
Unsymmetrical bisacridines(UAs) are a novel potent class of antitumor-active therapeutics.A significant route of phase II drug metabolism is conjugation with glutathione(GSH),which can be non-enzymatic and/or catalyze...Unsymmetrical bisacridines(UAs) are a novel potent class of antitumor-active therapeutics.A significant route of phase II drug metabolism is conjugation with glutathione(GSH),which can be non-enzymatic and/or catalyzed by GSH-dependent enzymes.The aim of this work was to investigate the GSHmediated metabolic pathway of a representative UA,C-2028.GSH-supplemented incubations of C-2028 with rat,but not with human,liver cytosol led to the formation of a single GSH-related metabolite.Interestingly,it was also revealed with rat liver microsomes.Its formation was NADPH-independent and was not inhibited by co-incubation with the cytochrome P450(CYP450) inhibitor 1-aminobenzotriazole.Therefore,the direct conjugation pathway occurred without the prior CYP450-catalyzed bioactivation of the substrate.In turn,incubations of C-2028 and GSH with human recombinant glutathione S-transferase(GST) P1-1 or with heat-/ethacrynic acid-inactivated liver cytosolic enzymes resulted in the presence or lack of GSH conjugated form,respectively.These findings proved the necessary participation of GST in the initial activation of the GSH thiol group to enable a nucleophilic attack on the substrate molecule.Another C-2028-GSH S-conjugate was also formed during non-enzymatic reaction.Both GSH S-conjugates were characterized by combined liquid chromatography/tandem mass spectrometry.Mechanisms for their formation were proposed.The ability of C-2028 to GST-mediated and/or direct GSH conjugation is suspected to be clinically important.This may affect the patient’s drug clearance due to GST activity,loss of GSH,or the interactions with GSH-conjugated drugs.Moreover,GST-mediated depletion of cellular GSH may increase tumor cell exposure to reactive products of UA metabolic transformations.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.31772213 and 31972320)the Excellent Youth Fund of Zhejiang Province,China(No.LR17C140002)
文摘An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system based on intergeneric conjugation was developed in Streptomyces rimosus M527,a bacterial strain which exhibits strong antagonistic activity against a broad range of plant-pathogenic fungi.Some experimental parameters involved in this procedure were optimized,including the conjugative media,ratio of donor to recipient,heat shock temperature,and incubation time of mixed culture.Under the optimal conditions,a maximal conjugation frequency of 3.05^10-5 per recipie nt was obtai ned.Subseque ntly,based on the above developed and optimized tran sformati on system,the synthetic promoters SPL-21 and SPL-57,a native promoter potrB,and a constitutive promoter permE commonly used for gene expression in streptomycetes were selected and their activity was analyzed using gusA as a reporter gene in S.rimosus M527.Among the four tested promoters,SPL-21 exhibited the strongest expression activity and gave rise to a 2.2-fold increase in p-glucuronidase(GUS)activity compared with the control promoter permE.Promoter SPL-57 showed activity comparable to that of permE.Promoter potrB,which showed the lowest activity,showed a 50%decrease in GUS activity compared with the control permE.The transformation system developed in this study and the tested promotors provide a basis for the further modification of S.rimosus M527.
文摘In this paper, we consider 2 × 2 non-cooperative elliptic system involving Laplace operator defined on bounded, continuous and strictly Lipschitz domain of Rn. First we prove the existence and uniqueness for the state of the system under conjugation conditions;then we discuss the existence of the optimal control of boundary type with Neumann conditions, and we find the set of equations and inequalities that characterize it.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(No.NRF-2021R1A2C2004109)the Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(No.P0020612,2022 The Competency Development Program for Industry Specialist).
文摘Wearable biosensors have received great interest as patient-friendly diagnostic technologies because of their high flexibility and conformability.The growing research and utilization of novel materials in designing wearable biosensors have accelerated the development of point-of-care sensing platforms and implantable biomedical devices in human health care.Among numerous potential materials,conjugated polymers(CPs)are emerging as ideal choices for constructing high-performance wearable biosensors because of their outstanding conductive and mechanical properties.Recently,CPs have been extensively incorporated into various wearable biosensors to monitor a range of target biomolecules.However,fabricating highly reliable CP-based wearable biosensors for practical applications remains a significant challenge,necessitating novel developmental strategies for enhancing the viability of such biosensors.Accordingly,this review aims to provide consolidated scientific evidence by summarizing and evaluating recent studies focused on designing and fabricating CP-based wearable biosensors,thereby facilitating future research.Emphasizing the superior properties and benefits of CPs,this review aims to clarify their potential applicability within this field.Furthermore,the fundamentals and main components of CP-based wearable biosensors and their sensing mechanisms are discussed in detail.The recent advancements in CP nanostructures and hybridizations for improved sensing performance,along with recent innovations in next-generation wearable biosensors are highlighted.CPbased wearable biosensors have been—and will continue to be—an ideal platform for developing effective and user-friendly diagnostic technologies for human health monitoring.
基金National Natural Science Foundation of China(No.92061117)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)+1 种基金Project of the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR129)Natural Science Foundation of Fujian Province,China(No.2020J01110).
文摘Understanding the quantum effect in the cross-conjugated system is of fundamental significance in molecular electronics.In this study,four molecules Xa-O,Xa,BP and BP-O were synthesized to investigate the destructive quantum interference(DQI)of a carbonyl bridge.The single-molecule conductance measured by the scanning tunneling microscope break junction(STM-BJ)technique demonstrates an increase in the conductance from molecule BP-O to molecule Xa-O as the cross-conjugated system is extended.Theoretical calculations show that the explicit DQI feature is presented in BP-O but absent in Xa-O,which indicates the removal of DQI in the restrained structures and results in the conductance enhancement in Xa-O.
文摘The existence and uniqueness of the state for 2 × 2 Dirichlet cooperative elliptic systems under conjugation conditions are proved using Lax-Milgram lemma, then the boundary control for these systems is discussed. The set of equations and inequalities that characterizes this boundary control is found by theory of Lions, Sergienko and Deineka. The problem for cooperative Neumann elliptic systems under conjugation conditions is also considered. Finally, the problem for <em>n</em> × <em>n</em> cooperative elliptic systems under conjugation conditions is established.
基金supported by the National Natural Science Foundation of China(No.32270558)。
文摘Ciliates are eukaryotic unicellular organisms with complex morphology and developmental processes,including asexual and sexual processes.Conjugation is a form of sexual process that renews genetic materials.However,visualizing conjugation in ciliates is a challenge due to the complexity and dynamics of the process,while traditional staining methods are often insufficient for the research.This study introduces a new method for visualizing developmental progression in the nuclei during conjugation using Hoechst33342 staining.It describes how to proceed from cell culture,conjugation induction and synchronization,staining preparation,and observation to statistical analysis.The combination of fluorescent staining with the‘volume-fixing'technique eliminates the fixation and dehydration steps,thus reducing the overall operation time to just 20 minutes.This method offers several advantages over traditional staining techniques for studying the nuclei during conjugation.It improves image quality and workflow efficiency and enables real-time observation of live cell states.Potential solutions to challenges that may arise during experimental procedures are introduced and references and guidelines for cytological research are provided in this paper.
文摘Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs)are constructed through co-entrapping glucose oxidase(GOx)and horseradish peroxidase(HRP),in which hydrogen peroxide(H_(2)O_(2)) is the intermediate product.The interplay of low-resistance mass transfer pathway and appropriate pore wall-H_(2)O_(2) interactions facilitates the directed transfer of H_(2)O_(2),resulting in 2.4-fold and 5.0-fold elevation in catalytic activ-ity compared to free ECSs and separated ECSs,respectively.The substrate channeling effect could be regulated by altering the mass ratio of GOx to HRP.Besides,I-ECSs demonstrate excellent stabili-ties in harsh environments and multiple recycling.
文摘Cell-free systems significantly improve network capacity by enabling joint user service without cell boundaries,eliminating intercell interference.However,to satisfy further capacity demands,it leads to high-cost problems of both hardware and power consumption.In this paper,we investigate multiple reconfigurable intelligent surfaces(RISs)aided cell-free systems where RISs are introduced to improve spectrum efficiency in an energy-efficient way.To overcome the centralized high complexity and avoid frequent information exchanges,a cooperative distributed beamforming design is proposed to maximize the weighted sum-rate performance.In particular,the alternating optimization method is utilized with the distributed closed-form solution of active beamforming being derived locally at access points,and phase shifts are obtained centrally based on the Riemannian conjugate gradient(RCG)manifold method.Simulation results verify the effectiveness of the proposed design whose performance is comparable to the centralized scheme and show great superiority of the RISs-aided system over the conventional cellular and cell-free system.
文摘During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century. Here we report on new details concerning the conjugation of P. caudatum through the staining of conjugating ceils with protargol, carbol fuchsin solution, Hoechst 33342 and immunofluorescence labeling with monoclonal antibody of anti-a tubulin. 1) The crescent nucleus is a characteristic of the meiotic prophase of P. caudatum, has an unstained area. We stained this area with protargol, which was separated from the chromatin area and was not detected by the other stainings. 2) In regards to the four meiotic products, it has long been considered that only one product enters the paroral cone region (PC) and survives after meiosis. However, our protargol and immunofluorescence labeling results indicated that PC entrance of the meiotic product happened before the completion of meiosis instead of after. 3) In our previous study, protargol staining indicated the presence of a swollen structure around the central part of the "U" and "V" shaped spindles connecting the two types of prospective pronuclei. However, immunofluorescence labeling with anti-a tubulin antibodies gave a different image from protargol. All these observations form the basis for further studies of their molecular mechanisms.
文摘After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating boundaries;while the stationary pronuclei are located beside the migratory pronuclei.To date,however,it is not clear what causes this close side-by-side localization between migratory and stationary pronuclei.In the current study,immunofluorescence staining with monoclonal antibody of anti-α tubulin indicated that "U" or "V" shaped spindles connected the migratory and stationary pronuclei during the third prezygotic division.This observation accounts for the close localization between these two types of pronuclei.
基金financially supported by the Sichuan Science and Technology Program(2022YFS0025 and 2024YFFK0133)supported by the“Fundamental Research Funds for the Central Universities of China.”。
文摘Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.
文摘Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and sufficient conditions for the existence of and the expressions for the msc solutions and the ssd solutions are obtained for the system.
基金partly supportedby National Natural Science Foundation of China(Grant No.41472103)
文摘Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of a large conjugate strike-slip fault system from the intracratonic Tarim Basin, NW China. Within our study area, "X" type NE and NW trending faults occur within Cambrian- Ordovician carbonates. The dihedral angles of these conjugate faults have narrow ranges, 19~ to 62~ in the Cambrian and 26~ to 51~ in the Ordovician, and their modes are 42~ and 44~ respectively. These data are significantly different from the ~60~ predicted by the Coulomb fracture criterion. It is concluded that: (1) The dihedral angles of the conjugate faults were not controlled by confining pressure, which was low and associated with shallow burial; (2) As dihedral angles were not controlled by pressure they can be used to determine the shortening direction during faulting; (3) Sequential slip may have played an important role in forming conjugate fault intersections; (4) The conjugate fault system of the Tarim basin initiated as rhombic joints; these subsequently developed into sequentially active "X" type conjugate faults; followed by preferential development of the NW-trending faults; then reactivation of the NE trending faults. This intact rhombic conjugate fault system presents new insights into mechanisms of dihedral angle development, with particular relevance to intracratonic basins.
基金partially the Chongqing Municipality’s Major Theme Project “R & D and Application of 5G terminal simulation equipment” (Grant No. Cstc2017zdcy-zdzx0030)
文摘The initial cell search plays an important role during the process of downlink synchronization establishment between the User Equipment(UE) and the base station. In particular, the uncertainty of the synchronization signals on the frequency domain and the flexibility of frame structure configuration have brought great challenges to the initial cell search for the fifth-generation(5G) new radio(NR). To solve this problem, firstly, we analyze the physical layer frame structure of 5G NR systems. Then, by focusing on the knowledge of synchronization signals, the 5G NR cell search process is designed, and the primary synchronization signal(PSS) timing synchronization algorithm is proposed, including a 5G-based coarse synchronization algorithm and conjugate symmetry-based fine synchronization algorithm. Finally, the performance of the proposed cell search algorithm in 5G NR systems is verified through the combination of Digital Signal Processing(DSP) and personal computer(PC). And the MATLAB simulation proves that the proposed algorithm has better performance than the conventional cross-correlation algorithm when a certain frequency offset exists.
文摘BACKGROUND: Dubin-Johnson syndrome (DJS) is a rare clinical entity. We describe a case of DJS complicated by systemic lupus erythematosus (SLE). METHODS: A case of congenital hyperbilirubinemia with SLE was evaluated systematically including review of history, physical examination for the stigmata of chronic liver disease, and other investigations. RESULT: Liver biopsy revealed a black liver with preserved architecture suggestive of DJS. CONCLUSIONS: SLE may develop in DJS. The relationship between DJS and SLE in this case is most likely a chance occurrence.
基金supported by the Major National Scientific Research Projects (2015CB932103)
文摘A pH-responsive conjugate based 10-hydroxycamptothecin-thiosemicarbazide-polyethene glycol 2000 (10-HCPT-hydro-PEG) nano-micelles were prepared in our previous study. In the present study, ultra-performance liquid chromatography (UPLC-MS) method is developed to investigate its pharmacokinetics and biodistribution in tumor bearing mice. The results demonstrated that the conjugate circulated for a much longer time in the blood circulation system than commercial 10-HCPT injection, and bioavailability was significantly improved compared with 10-HCPT. In vivo biodistribution study showed that the conjugate could enhance the targeting and residence time in tumor site.
基金Projects(40974077,41164004)supported by the National Natural Science Foundation of ChinaProject(2007AA06Z134)supported by the National High Technology Research and Development Program of China+2 种基金Projects(2011GXNSFA018003,0832263)supported by the Natural Science Foundation of Guangxi Province,ChinaProject supported by Program for Excellent Talents in Guangxi Higher Education Institution,ChinaProject supported by the Foundation of Guilin University of Technology,China
文摘The strategies that minimize the overall solution time of multiple linear systems in 3D finite element method (FEM) modeling of direct current (DC) resistivity were discussed. A global stiff matrix is assembled and stored in two parts separately. One part is associated with the volume integral and the other is associated with the subsurface boundary integral. The equivalent multiple linear systems with closer right-hand sides than the original systems were constructed. A recycling Krylov subspace technique was employed to solve the multiple linear systems. The solution of the seed system was used as an initial guess for the subsequent systems. The results of two numerical experiments show that the improved algorithm reduces the iterations and CPU time by almost 50%, compared with the classical preconditioned conjugate gradient method.
基金supported by the National Natural Science Foundation of China(60872026)the Natural Science Foundation of Tianjin(09JCZDJC16900)
文摘This paper presents an algorithm that aims to reduce the peak-to-average power ratio(PAPR) of orthogonal frequency division multiplexing(OFDM) communication systems while maintaining frequency tracking.The algorithm achieves PAPR reduction by applying the complex conjugates of the data symbol obtained from the frequency domain to cancel the phase of the data symbol.A likelihood estimator is used to obtain the sub-carrier phase error due to the residual carrier frequency offset(RCFO) using the same complex conjugates as a pilot signal.Furthermore,a joint time and frequency domain multicarrier phase locked loop(MPLL) is developed to compensate additional frequency offset.Simulation results show that this algorithm is capable of reducing PAPR without impacting the frequency tracking performance.
基金the Sichuan Science and Technology Program (2019YJ0162)the National Natural Science Foundation of China (21402023, 51773027)the National Key R@D Program of China (2017YFB0702802) for financial support。
文摘Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite solar cells(PSCs) are synthesized by facile one-step reaction in good yield over 75%. DTF unit as electron donor can enhance the electron donating ability and the fusion of benzenic ring of TPA with DTF unit may lead to reinforced intermolecular interactions in the solid state. In addition,WH-2 and WH-3 exhibit a pyramid shape containing partial planarity and quasi three-dimensionality features, which is also conducive to enhancing the π-π stacking of molecules in the solid state. The above-mentioned structural characteristics make the two HTMs have good hole mobilities. As a result,WH-2 and WH-3 obtained the high intrinsic hole mobilities of 4.69 × 10^(-4)and 2.18 × 10^(-3)cm^(2)V^(-1)s^(-1)respectively. Finally, the power conversion efficiencies(PCEs) of PSCs with WH-2 and WH-3 as cost-effective dopant-free HTMs are 15.39% and 19.22% respectively and the PCE of PSC with WH-3 is on a par with that of PSC with Li-TFSI/t-BP doped Spiro-OMe TAD(19.67%).
文摘Unsymmetrical bisacridines(UAs) are a novel potent class of antitumor-active therapeutics.A significant route of phase II drug metabolism is conjugation with glutathione(GSH),which can be non-enzymatic and/or catalyzed by GSH-dependent enzymes.The aim of this work was to investigate the GSHmediated metabolic pathway of a representative UA,C-2028.GSH-supplemented incubations of C-2028 with rat,but not with human,liver cytosol led to the formation of a single GSH-related metabolite.Interestingly,it was also revealed with rat liver microsomes.Its formation was NADPH-independent and was not inhibited by co-incubation with the cytochrome P450(CYP450) inhibitor 1-aminobenzotriazole.Therefore,the direct conjugation pathway occurred without the prior CYP450-catalyzed bioactivation of the substrate.In turn,incubations of C-2028 and GSH with human recombinant glutathione S-transferase(GST) P1-1 or with heat-/ethacrynic acid-inactivated liver cytosolic enzymes resulted in the presence or lack of GSH conjugated form,respectively.These findings proved the necessary participation of GST in the initial activation of the GSH thiol group to enable a nucleophilic attack on the substrate molecule.Another C-2028-GSH S-conjugate was also formed during non-enzymatic reaction.Both GSH S-conjugates were characterized by combined liquid chromatography/tandem mass spectrometry.Mechanisms for their formation were proposed.The ability of C-2028 to GST-mediated and/or direct GSH conjugation is suspected to be clinically important.This may affect the patient’s drug clearance due to GST activity,loss of GSH,or the interactions with GSH-conjugated drugs.Moreover,GST-mediated depletion of cellular GSH may increase tumor cell exposure to reactive products of UA metabolic transformations.