ObjectiveThe malaria parasites remodel the host erythrocyte structure by exporting parasite proteins that interact with the membrane skeleton proteins of red blood cells (RBCs), facilitating their intracellular survival and pathogenicity. Skeleton-binding protein 1 (SBP1) is a conserved exported protein across Plasmodium species. In Plasmodium falciparum, SBP1 has been reported to interact with erythrocyte membrane skeleton proteins 4.1R and spectrin, while its contribution to erythrocyte remodeling and parasite virulence in Plasmodium berghei (Pb) remains unclear. This study aims to determine whether PbSBP1 associates with the host cytoskeletal protein 4.1R and to investigate its role in the remodeling of host RBCs and the pathogenicity of Plasmodium berghei. MethodsIn Plasmodium berghei, the relationship between PbSBP1 and the erythrocyte cytoskeletal protein 4.1R was examined using co-immunoprecipitation. A Pbsbp1 gene knockout mutant of Plasmodium berghei (Pbsbp1∆) was generated based on the principle of double crossover homologous recombination. The deformability of erythrocytes infected with Pbsbp1∆ parasites was assessed using microfluidic methods. Microchannels with an array of cylindrical pillars were used to detect modifications in infected RBC deformability. The infected RBCs were squashed between the rows and recovered between the columns and the transit velocity (μm/s) of infected RBCs travelling through the microchannel was recorded. The component of the erythrocyte membrane skeleton junctional complex, tropomodulin (TMOD), was fluorescently labeled, and the cytoskeletal network of infected erythrocytes was imaged using super-resolution stochastic optical reconstruction microscopy (STORM) to analyze ultrastructural changes in the cytoskeleton of wild-type (WT) and Pbsbp1∆-infected erythrocytes. Actin-based junctional complexes were displayed as individual clusters by the labeled TMOD in the STORM images, and the cluster densities and distances between adjacent clusters of infected RBCs were calculated. Additionally, rodent malaria models (BALB/c mice) and experimental cerebral malaria models (C57BL/6 mice) were employed to monitor the growth of Pbsbp1∆ and WT parasites during the intraerythrocytic stage and their capacity to induce cerebral malaria in mice. ResultsPbSBP1 may participate in the remodeling of infected erythrocytes through direct or indirect interaction with the erythrocyte cytoskeletal protein 4.1R. Microfluidic assays revealed that the deformability of erythrocytes infected with Pbsbp1∆ parasites was significantly enhanced compared to those infected with WT parasites. STORM imaging further demonstrated that the ultrastructure of the erythrocyte cytoskeleton in Pbsbp1∆-infected cells was altered relative to that in WT-infected erythrocytes. The distances between nearest neighbors of clusters had a tendency to increase while the cluster densities were decreased in Pbsbp1∆-infected RBCs compared to WT-infected RBCs. Subsequent phenotypic analysis indicated that the growth rate of Pbsbp1∆ parasites during the intraerythrocytic stage was significantly slower than that of WT parasites, and their ability to induce cerebral malaria in mice was also attenuated. These findings suggest that PbSBP1 is involved in the remodeling of the erythrocyte membrane skeleton, likely through its direct or indirect interaction with protein 4.1R, thereby regulating the deformability of infected erythrocytes and influencing the pathogenicity of the blood-stage parasites. ConclusionThis study establishes a role for PbSBP1 in host erythrocyte remodeling and parasite virulence, providing new research strategies for the prevention and treatment of malaria.

ObjectiveTo establish and evaluate a hyperuricemia （HUA） mouse model with the damp-turbidity internal accumulation syndrome. MethodsThirty-six C57BL/6J mice were randomly divided into control group， chemically induced model group （Model）， and model combined with high-fat and fatigue group （Model+HF）. Twenty-four uricase gene knockout （UOX^-/-） mice were randomly divided into UOX^-/- group and UOX^-/-+HF group， with 12 mice in each group. The Model group and the Model+HF group established the HUA model by intragastric administration of potassium oxyazinate combined with adenine. The Model+HF group and the UOX^-/-+HF group adopted a high-fat diet combined with weight-bearing exhaustive swimming to establish the HUA model with the damp-turbidity internal accumulation syndrome. On day 1， 7， 14， 21， and 28 after modeling， the damp-turbidity internal accumulation syndrome score of each group was evaluated. On day 1 and day 28， a weight-bearing swimming exhaustion test was performed， and the exhaustive swimming time was recorded. On day 28， liver and kidney indexes were calculated， and hematoxylin-eosin （HE） staining was used to observe histopathological changes in liver and kidney tissues. Serum levels of uric acid （UA）， xanthine dehydrogenase （XDH）， xanthine oxidase （XOD） and urea nitrogen （BUN） were detected through biochemical assays. ELISA was used to detect serum levels of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β）. Immunohistochemistry was used to detect the protein expression of organic anion transporter 1 （OAT1） and glucose transporter 9 （GLUT9） in renal tissues. Quantitative real-time PCR （qRT-PCR） was used to detect the mRNA expressions of adenosine triphosphate binding transporter G2 （ABCG2）， hypoxia-inducible factor-1α （HIF-1α）， urate anion transporter 1 （URAT1）， and GLUT9 in renal tissues. ResultsOn day 14 of modeling， the damp-turbidity internal accumulation syndrome scores of mice in the Model+HF group and the UOX^-/-+HF group were elevated compared with the control group（P＜0.05）； on day 28， the scores significantly increased， and the exhaustive swimming time was shortened （P＜0.01）， indicating successful establishment of the damp-turbidity internal accumulation syndrome model. Compared with the control group， all other groups exhibited increased kidney index， serum levels of UA， XDH， XOD， BUN， TNF-α， and IL-1β， elevated renal mRNA expression of HIF-1α， URAT1， OAT1， and GLUT9， and decreased renal ABCG2 mRNA expression （P＜0.01 or P＜0.05）. Significant pathological damage in the kidney was observed in the Model+HF group and the UOX^-/-+HF group compared to the Model group and the UOX^-/- group， with decreased serum UA and increased BUN and TNF-α levels （P＜0.05 or P＜0.01）， as well as increased expression of OAT1 and GLUT9 in the renal tissue. ConclusionBoth chemical induction and gene knockout， combined with a high-fat diet and weight-bearing exhaustive swimming， can successfully establish mouse models of HUA with damp-turbidity internal accumulation syndrome. Chemical induction is simple to operate and cost-effective， suitable for short-term drug screening， while UOX gene knockout induces spontaneous elevation of serum uric acid levels without drug administration， which may better mimick human metabolic characteristics.

ObjectiveTo establish and evaluate a hyperuricemia （HUA） mouse model with the damp-turbidity internal accumulation syndrome. MethodsThirty-six C57BL/6J mice were randomly divided into control group， chemically induced model group （Model）， and model combined with high-fat and fatigue group （Model+HF）. Twenty-four uricase gene knockout （UOX^-/-） mice were randomly divided into UOX^-/- group and UOX^-/-+HF group， with 12 mice in each group. The Model group and the Model+HF group established the HUA model by intragastric administration of potassium oxyazinate combined with adenine. The Model+HF group and the UOX^-/-+HF group adopted a high-fat diet combined with weight-bearing exhaustive swimming to establish the HUA model with the damp-turbidity internal accumulation syndrome. On day 1， 7， 14， 21， and 28 after modeling， the damp-turbidity internal accumulation syndrome score of each group was evaluated. On day 1 and day 28， a weight-bearing swimming exhaustion test was performed， and the exhaustive swimming time was recorded. On day 28， liver and kidney indexes were calculated， and hematoxylin-eosin （HE） staining was used to observe histopathological changes in liver and kidney tissues. Serum levels of uric acid （UA）， xanthine dehydrogenase （XDH）， xanthine oxidase （XOD） and urea nitrogen （BUN） were detected through biochemical assays. ELISA was used to detect serum levels of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β）. Immunohistochemistry was used to detect the protein expression of organic anion transporter 1 （OAT1） and glucose transporter 9 （GLUT9） in renal tissues. Quantitative real-time PCR （qRT-PCR） was used to detect the mRNA expressions of adenosine triphosphate binding transporter G2 （ABCG2）， hypoxia-inducible factor-1α （HIF-1α）， urate anion transporter 1 （URAT1）， and GLUT9 in renal tissues. ResultsOn day 14 of modeling， the damp-turbidity internal accumulation syndrome scores of mice in the Model+HF group and the UOX^-/-+HF group were elevated compared with the control group（P＜0.05）； on day 28， the scores significantly increased， and the exhaustive swimming time was shortened （P＜0.01）， indicating successful establishment of the damp-turbidity internal accumulation syndrome model. Compared with the control group， all other groups exhibited increased kidney index， serum levels of UA， XDH， XOD， BUN， TNF-α， and IL-1β， elevated renal mRNA expression of HIF-1α， URAT1， OAT1， and GLUT9， and decreased renal ABCG2 mRNA expression （P＜0.01 or P＜0.05）. Significant pathological damage in the kidney was observed in the Model+HF group and the UOX^-/-+HF group compared to the Model group and the UOX^-/- group， with decreased serum UA and increased BUN and TNF-α levels （P＜0.05 or P＜0.01）， as well as increased expression of OAT1 and GLUT9 in the renal tissue. ConclusionBoth chemical induction and gene knockout， combined with a high-fat diet and weight-bearing exhaustive swimming， can successfully establish mouse models of HUA with damp-turbidity internal accumulation syndrome. Chemical induction is simple to operate and cost-effective， suitable for short-term drug screening， while UOX gene knockout induces spontaneous elevation of serum uric acid levels without drug administration， which may better mimick human metabolic characteristics.

[This corrects the article DOI: 10.1016/j.apsb.2024.03.030.].

Chemiluminescence,as a self-luminous phenomenon that does not require light,heat,acoustic,electric and magnetic excitation,has been widely used in the fields of analytical chemistry,cold light source and bio-imaging because of its advantages including high sensitivity,wide linear range,simple equipment and fast detection speed compared with other analytical techniques.Carbon dots(CDs)are a class of nanomaterials with excellent photoluminescence properties and high biocompatibility.CDs are stable,easy to prepare and abundant in types,and researchers have introduced many types of CDs into different chemiluminescence systems.In this paper,the applications of CDs in common chemiluminescence systems and the possible mechanisms of action were discussed,and the research progresses on the application of CDs in different chemiluminescence detection fields in recent years were summarized.Finally,the development trend of CDs in chemiluminescence was analyzed.

Chrysophanol(Chr)and physcion(Phy)are primary active ingredients of a well-known traditional Chinese medicine namely rhubarb(Chinese name:Dahuang),and their glucuronides have been revealed as the dominant forms presenting in rats after oral administration.Either Chr or Phy has two glycosylation sites,resulting in a pair of positional isomers for glucuronides of either compound(CG1&CG2 and PG1&PG2).To confirmatively identify these glucuronides,energy-resolved mass spectrometry(ER-MS)was used to pursue the fragmentation trajectories of the targeted fragment ions,and the resultant breakdown graphs that were described by the optimal collision energy(OCE)were expected to exhibit the differences of glycosidic bond cleavage between the isomers.Quantum chemical calculation was thereafter conducted to produce the bond dissociation energy(BDE)of the glycosidic bonds.The isomers were unambiguously identified through applying the positive correlation rule between OCE and BDE.Fortunately,the glucuronides of Chr and Phy in vivo were observed through liver microsomes incubationin vitro.ER-MS was utilized to collect the Gaussian-shaped breakdown graphs in response to the neutral loss of 176 Da,and the absolute values of OCE were compared between positional isomers.The results revealed that CG1(-32.31 eV)>CG2(-31.61 eV),and nonetheless,PG1(-30.00 eV)Chr-8-GluA(-48.787 kJ/mol),and nonetheless,Phy-1-GluA(-48.672 kJ/mol)

Surface enhanced Raman scattering(SERS)is an important technique for detecting pesticide residues.However,many pesticides have small Raman scattering cross sections and low affinity for gold/silver enhancement substrates,resulting in low sensitivity for direct SERS detection.Indirect methods typically require complex surface modifications and have poor universality.Here,a dual functional composite Au@MnO2 combined with acetylcholinesterase(AChE)was proposed for SERS biosensing of pesticides.The Au@MnO2 with oxidase-like activity could oxidize 3,3′,5,5′-tetramethylbenzidine(TMB)into oxTMB with a large Raman scattering cross section,producing strong SERS signal using Au@MnO2 itself as enhancement substrate.In the presence of AChE,acetylthiocholine(ATCh)was catalytically hydrolyzed to produce thiocholine(TCh),and its reducibility could induce the decomposition of MnO2.Consequently,oxidase-like activity of Au@MnO2 was declined,less oxTMB was produced,and gold nanoparticles(AuNPs)detached from the MnO2 layer,resulting in a weakened SERS response.Organophosphorus pesticides(OPs),as inhibitors of AChE,prevented the production of TCh,thereby blocking the decomposition of MnO2 and leading to the recovery of Raman signals.Under optimized conditions,the Raman signal switching strategy was successfully used for detection of three OPs,i.e.,fenthion,chlorpyrifos,and methyl parathion,with detection limits of 4×10-11 mol/L,2×10-9 mol/L,and 3×10-9 mol/L,respectively.In actual spinach sample testing,the spiked recoveries of the three OPs ranged from 86.5%to 110.6%.This study provided a new strategy for detecting pesticide residues using SERS.

Traditional mass measurement methods are not applicable in microgravity environments,and the main challenge for in-orbit body mass measurement technology based on inertial principles is to address the random errors brought about by the weightless environment.These include additional torques due to shifts in the center of mass,nonlinear accelerations due to non-rigid human bodies,mechanical energy consumption due to organ vibrations,and random vibrations of the measurement device itself.To address the above difficulties,the project proposes a technical scheme based on the principle of linear acceleration,designs and constructs a ground-specific air-floating experimental and simulation platform,studies key data such as motion trajectory,acceleration change,and vibration frequency amplitude during the mass measurement process,and simulates the changes in the center of mass and random vibrations of the human body in a weightless environment.The project has designed an adjustable posture bracket to adapt to changes in the center of mass,enhance body restraint,and greatly reduce shaking;it has also developed an integrated four-bar linkage motion guidance mechanism,high-precision integrated photoelectric distance measurement,and modular motion constant force measurement device to ensure the accurate measurement of acceleration and constant force data.The product has undergone simulation calculations,ground human applicability tests,and in-orbit applicability verification in the space station.Ground test results show that the device achieves a body mass measurement accuracy better than 0.5%,and the dispersion is better than 0.38%;after flight mission verification and evaluation,the in-orbit body mass measurement dispersion is less than 0.4%,which is superior to the SLAMMD,a mass measurement device of the same principle on the International Space Station,and is at the forefront internationally,achieving accurate body mass measurement.