ObjectiveThe widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF) technologies. Image-based methods relying on sharpness evaluation require iterative searches, resulting in slow convergence, while projection-based techniques are susceptible to optical artifacts and calibration errors. To address these challenges, this study introduces a novel AF system based on direct wavefront sensing, designed to deliver simultaneous high speed, high precision, and operational robustness within the compact form factor essential for portable ophthalmic devices. MethodsOur approach fundamentally reimagines the AF process by directly measuring the ocular wavefront aberration. We developed a custom portable fundus camera integrating a miniaturized Shack-Hartmann wavefront sensor (SHWS) into the optical path. An 850 nm laser diode projects a point source onto the retina via oblique illumination to minimize corneal reflections. Light scattered from this spot carries the eye’s refractive error through the imaging optics and is directed to the SHWS, positioned at a plane optically conjugate to the primary color CMOS imaging sensor. A microlens array within the SHWS samples the incident wavefront, generating a pattern of focal spots on a CCD. Real-time centroid analysis of these spots provides a map of local wavefront slopes. These measurements are processed through a singular value decomposition (SVD) algorithm to fit a Zernike polynomial basis set, enabling real-time reconstruction of the wavefront phase. The defocus component (S) is extracted from the second-order Zernike coefficients, providing a direct, quantitative measure of the refractive error in diopters. This value serves as a precise error signal in a closed-loop control system, which commands a voice-coil actuated focusing lens to its null position in a single, deterministic step, eliminating the need for iterative search algorithms. ResultsComprehensive evaluation demonstrated the system’s high performance. Testing on a calibrated model eye (OEMI-7) established a highly linear relationship between the computed defocus S and the focusing lens position across a ±20 Diopter (D) compensation range, achievable within a 5 mm mechanical travel. The system achieved a focusing precision of 0.08 D, corresponding to an 18-fold improvement over a conventional projection spot-size method tested under identical conditions. The total focus acquisition time, encompassing wavefront measurement, computation, and lens actuation, averaged under 0.5 s. Clinical validation with 25 human volunteers (50 eyes, refractive range -15 D to +10 D) confirmed practical efficacy. The wavefront-sensing AF succeeded in 92% of attempts with a mean time of 0.5 s, substantially outperforming a projection-based benchmark which achieved only a 32% success rate with an average time of 4.25 s. The system provided instantaneous directional guidance and maintained stability during minor ocular movements. Objective assessment of image quality, via amplitude contrast of retinal vasculature, showed consistent and significant enhancement following AF correction across the entire tested diopter range. ConclusionThis work successfully implements and validates a direct wavefront-sensing autofocus paradigm for portable fundus cameras. By directly quantifying and compensating for the optical defocus aberration, this method bypasses the fundamental limitations of image-processing and projection-based techniques, enabling rapid, precise, and deterministic diopter compensation. The developed system delivers an exceptional combination of a wide operational range (±20 D), high accuracy (0.08 D), fast convergence (0.5 s), and a compact physical footprint. This technology provides a practical and high-performance focusing solution capable of enhancing the reliability, throughput, and diagnostic utility of portable retinal imaging in large-scale screening applications. Future efforts will be directed towards system cost optimization and performance adaptation for diverse ocular conditions.

Objective To investigate the mechanism by which angiotensin Ⅱ type 1 receptor autoantibody(AT1-AA)promotes phenotypic switch of vascular smooth muscle cells(VSMCs)and vascular fibrosis through abnormal expression of circadian clock protein BMAL1.Methods Twelve male SD rats(6～8 weeks old,weighing 180～220 g)were randomly divided into(n=6)a control group and an AT1-AA-positive group[established by active immunization of SD rats with AT1R extracellular loop Ⅱ peptide(AT1R-ECLⅡ)].HE and Masson stainings were used to observe structural changes and fibrosis in the thoracic aorta(n=3).Western blotting was performed to detect the expression of Collagen I,phenotypic switch-related proteins(SM22,α-SMA,OPN and MMP2)in vascular tissues and primary VSMCs(n=4),as well as the expression of BMAL1 at CT0,CT4,CT8,CT12,CT16,and CT20.Transwell and scratch assays were used to assess the proliferation and migration of VSMCs(n=3).si-RNA was employed to knock down Bmal1,followed by detection of BMAL1,Collagen I,and phenotypic conversion-related protein expression(n=3).Additionally,AT1-AA-positive AT1R-knockout(AT1R-KO)rats were constructed to measure BMAL1 expression in thoracic aortic tissues(n=4).Results The AT1-AA-positive rats had significantly thickened thoracic aortic vessel wall[(140±9)%vs(120±5)%,P<0.05],badly arranged VSMCs,obvious blue Masson staining,and up-regulated Collagen I expression(P<0.05).In the thoracic aorta of AT1-AA-positive rats and AT1-AA-treated VSMCs,the expression of contractile phenotype-related proteins(α-SMA,SM22)was decreased(P<0.05),while the expression of synthetic phenotype-related proteins(OPN,MMP2)was increased(P<0.05).AT1-AA enhanced the scratch healing ability and migration ability of VSMCs.Furthermore,both mRNA and protein levels of Bmal1 were significantly up-regulated at CT12(P<0.05),and the rhythmicity of Bmal1 was lost.Knockdown of Bmal1 partially ameliorated AT1-AA-induced phenotypic switch of VSMCs.Compared with AT1-AA-positive WT rats,AT1-AA-positive AT1R-KO rats showed significantly reduced BMAL1 expression in the thoracic aorta(1.35±0.06 vs 0.86±0.07,P<0.001).At the cellular level,AT1-AA-induced phenotypic switch and high Collagen I expression in VSMCs were partially improved in AT1R-KO VSMCs.Conclusion AT1-AA promotes VSMCs phenotypic conversion and vascular fibrosis through the AT1R-Bmal1 axis.

In this work,four salicylhydrazone compounds(L1?L4)were designed and synthesized by using vanillin derivatives as raw material.The structures were confirmed by nuclear magnetic resonance(NMR)and high-resolution mass spectrometry(HRMS).The optical experiments showed that probe L1 and probe L3 could be used as aluminium ion(Al3+)fluorescence probes.The fluorescence color of probe L1 solution changed from colorless to blue after adding Al3+,and the limit of detection was 25.1 nmol/L.Compared with probe L1,the fluorescence color of probe L3 solution changed from colorless to green after complexing with Al3+,and the limit of detection was 17.3 nmol/L.Probe L1 and probe L3 showed the advantages of fast response speed,high selectivity and good anti-interference.The mechanism of Al3+recognition was further demonstrated by HRMS and 1H NMR.Cell imaging experiments showed that probe L1 and L3 had low cytotoxicity and had great application potential in detection of Al3+in vivo.

Current ambient mass spectrometry ionization often requires external auxiliary equipment such as high-voltage power supply,gas cylinder,and syringe pump.Moreover,the process of sample preparation is cumbersome,and the experimental operations are complex,which makes it difficult to adapt to real-time on-site detection.In this work,a novel method was proposed,in which direct sampling of raw samples,online extraction of interest analytes,and ionization of target molecules were integrated into a single unit.With the developed method,the in-situ extraction and nano-electrospray ionization for both liquid and solid raw samples were achieved.Also,a handheld ion source and its pose adjustment device were developed,and the position and angle parameters were subsequently optimized.The performance of the ionization device was tested using standard solutions of caffeine and reserpine.The limits of detection(LODs)were 0.08 μg/L and 0.14 μg/L,with relative standard deviations(RSDs)≤3.7% and≤5.6%,respectively,indicating that the device possessed high sensitivity and stability.Using this device,three different concentrations of reserpine standard solutions were continuously tested for five days.The intra-day RSDs were consistently≤4.7% and the inter-day RSDs were all≤10.3%,showing the good working stability of the device.Without any pretreatment,a rapid qualitative detection of medicinal components including astragaloside II and cycloastragenol in five traditional Chinese medicines was carried out,with RSDs≤8.0% and≤7.1%,respectively.Additionally,rapid qualitative detection of gallic acid,a medicinal component,in white peony roots,and hypaphorine as well as quercetin in cowherb seeds were carried out,with RSDs≤7.0%,≤6.4% and≤6.1%,respectively.These results demonstrated that the ionization technology and device exhibited good stability during qualitative detection of raw samples.

The continuous accumulation of plastic waste such as polyethylene in the environment has caused serious environmental pollution issues.Considering the high similarity in the molecular structure of petroleum and polyolefin,it is feasible to apply rare earth-zeolite catalysts in polyolefin plastic upcycling,which is commonly used in fluid catalytic cracking(FCC)in the field of petroleum refining.In this study,Ce-modified HY(Ce-HY)zeolites were synthesized and characterized by a series of analytical methods,such as high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM),Fourier infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),etc.When introducing 5% Ce species into HY zeolites,the 5Ce-HY showed excellent catalytic performance in the catalytic cracking of low-density polyethylene(LDPE),which achieved 98.4% LDPE conversion with 91.5% selectivity of gaseous alkanes at 300℃,and 75.4% of them were isoparaffins.In addition,the effect of the location of rare earth species in Y zeolites on the catalytic performance was explored by fine X-ray diffraction(XRD)in the range of 11°-13°and in situ-Raman analyses.The Ce species located in the supercage of Y zeolites were more important,which enhanced the adsorption capacity and accessibility of substrate molecules,thus facilitating the entire catalytic cracking process.This method could be used to detect the location of rare earth elements in Y zeolites to understand the mechanism of rare earth catalysis.

Caenorhabditis elegans,as an emerging model organism,has been widely used in multiple disciplines such as medicine,life science,and environmental science in recent years,due to its charac-teristics of short life cycle,clear genetic background,highly conserved evolution,complete genome analysis and excellent fitting between experimental data and human results.It also shows unique advan-tages in the field of toxicology.This paper summarizes its advantages in toxicological research starting from the biological characteristics of C.elegans,introduces the toxicological research methods and progress based on the C.elegans model,focuses on demonstrating its applications in environmental fo-rensic medicine and forensic toxicology,and looks forward to the application of the relevant results in the field of forensic science.

BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

This study explores the effect and mechanism of Banxia Xiexin Decoction(BXD) in inhibiting colon cancer progression by reshaping tryptophan metabolism. Balb/c mice were assigned into control, model, low-dose BXD(BXD-L), and high-dose BXD(BXD-H) groups. Except the control group, the other groups were subcutaneously injected with CT26-Luc cells for the modeling of colon cancer, which was followed by the intervention with BXD. Small animal live imaging was employed to monitor tumor growth, and the tumor volume and weight were measured. Hematoxylin-eosin(HE) staining was used to observe the pathological changes in mouse tumors. Immunohistochemistry was used to detect Ki67 expression in tumors. Immunofluorescence and flow cytometry were used to detect the infiltration and number changes of CD3~+/CD8~+ T cells in the tumor tissue. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interferon-gamma(IFN-γ) and interleukin-2(IL-2) in tumors. Targeted metabolomics was employed to measure the level of tryptophan(Trp) in the serum, and the Trp content in the tumor tissue was measured. Western blot and RT-qPCR were employed to determine the protein and mRNA levels, respectively, of indoleamine 2,3-dioxygenase 1(IDO1), MYC proto-oncogene, and solute carrier family 7 member 5(SLC7A5) in the tumor tissue. Additionally, a co-culture model with CT26 cells and CD8~+ T cells was established in vitro and treated with the BXD-containing serum. The cell counting kit-8(CCK-8) assay was used to examine the viability of CT26 cells. The content of Trp in CT26 cells and CD8~+ T cells, as well as the secretion of IFN-γ and IL-2 by CD8~+ T cells, was measured. RT-qPCR was used to determine the mRNA levels of MYC and SLC7A5 in CT26 cells. The results showed that BXD significantly inhibited the tumor growth, reduced the tumor weight, and decreased the tumor volume in the model mice. In addition, the model mice showed sparse arrangement of tumor cells, varying degrees of patchy necrosis, and downregulated expression of Ki67 in the tumor tissue. BXD elevated the levels of IFN-γ and IL-2 in the tumor tissue, while upregulating the ratio of CD3~+/CD8~+ T cells and lowering the levels of Trp, IDO1, MYC, and SLC7A5. The co-culture experiment showed that BXD-containing serum reduced Trp uptake by CT26 cells, increased Trp content in CD8~+T cells, enhanced IL-2 and IFN-γ secretion of CD8~+T cells, and down-regulated the mRNA levels of MYC and SLC7A5 in CT26 cells. In summary, BXD can inhibit the MYC/SLC7A5 pathway to reshape Trp metabolism and adjust Trp uptake by CD8~+ T cells to enhance the cytotoxicity, thereby inhibiting the development of colon cancer.
Animals ; Tryptophan/metabolism* ; Colonic Neoplasms/pathology* ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Mice, Inbred BALB C ; Humans ; Cell Line, Tumor ; Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism* ; Female ; Disease Progression ; Cell Proliferation/drug effects* ; Proto-Oncogene Mas ; Male

In this study, Saccharomyces cerevisiae R0 was used as the chassis cell to synthesize oleanolic acid from scratch through the heterologous expression of β-amyrin synthase(β-AS) from Glycyrrhiza uralensis, cytochrome P450 enzyme CYP716A154 from Catharanthus roseus, and cytochrome P450 reductase AtCPR from Arabidopsis thaliana. The engineered strain R1 achieved shake flask titres of 5.19 mg·L~(-1). By overexpressing enzymes in the pentose phosphate pathway(PPP)(ZWF1, GND1, TKL1, and TAL), the NADH kinase gene in the mitochondrial matrix(POS5), truncated 3-hydroxy-3-methylglutaryl-CoA reductase(tPgHMGR1) from Panax ginseng, and farnesyl diphosphate synthase gene(SmFPS) from Salvia miltiorrhiza, the precursor supply and intracellular reduced nicotinamide adenine dinucleotide phosphate(NADPH) supply were enhanced, resulting in an 11.4-fold increase in squalene yield and a 3.6-fold increase in oleanolic acid yield. Subsequently, increasing the copy number of the heterologous genes tPgHMGR1, β-AS, CYP716A154, and AtCPR promoted the metabolic flow towards the final product, oleanolic acid, and increased the yield by three times. Shake flask fermentation data showed that, by increasing the copy number, precursor supply, and intracellular NADPH supply, the final engineered strain R3 could achieve an oleanolic acid yield of 53.96 mg·L~(-1), which was 10 times higher than that of the control strain R1. This study not only laid the foundation for the green biosynthesis of oleanolic acid but also provided a reference for metabolic engineering research on other pentacyclic triterpenoids in S. cerevisiae.
Oleanolic Acid/biosynthesis* ; Saccharomyces cerevisiae/metabolism* ; Industrial Microbiology ; Microorganisms, Genetically-Modified/metabolism* ; Plants/enzymology* ; Fermentation ; Metabolic Engineering