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.

BACKGROUND:Streptococcus mutans is an important pathogen of dental caries,and timely detection of its levels is of great significance for early detection and treatment of dental caries. OBJECTIVE:To evaluate the effect of loop-mediated isothermal amplification(FTA-LAMP)direct extraction of Streptococcus mutans DNA. METHODS:(1)Bacterial suspensions containing ATCC standard strains(Streptococcus mutans)were prepared and inoculated into the brain-heart leachate medium.After mixed thoroughly,the mixture was then diluted in a 10-fold gradient into seven concentrations(4.2×107,4.2×106,4.2×105,4.2×104,4.2×103,4.2×102,4.2×10 CFU/mL),two parallel controls were made for each dilution level,and sterile water was used as a blank control.(2)The DNA of Streptococcus mutans was extracted using FTA Elute card,boiling method,kit extraction and lysate extraction methods separately and then amplified using LAMP technology was amplified.A specificity test was also performed to compare the differences between the four DNA extraction methods.RESULTS AND CONCLUSION:The DNA extracted by all four methods met the requirements for LAMP amplification.Specificity test results showed that only Streptococcus mutans could specifically amplify the target gene.The detection limit value of the DNA concentration was 4.2×103 CFU/mL for the lysate method,4.2×104 CFU/mL for the FTA Elute card extraction method,4.2×106 CFU/mL for the kit extraction method,and 4.2×107 CFU/mL for the boiling method.In the other aspects of the four extraction methods,the kit extraction method had the highest experimental cost,number of steps and time;the other three methods had the same number of steps,with the FTA Elute card method requiring the least amount of instruments,the boiling method having the lowest single cost,and the lysate extraction method taking the least amount of time.Only a small amount of bacteria were needed for successful extraction using both the FTA Elute card and lysate extraction methods.Compared with the FTA Elute card method,the lysate extraction method was superior in terms of time,but it had a high single cost and required more equipment.To conclude,the FTA-LAMP technology established in this study has the advantages of ease of operation,high specificity,high sensitivity,and visualization,which is expected to be a new way for efficient extraction and detection of Streptococcus mutans.

BACKGROUND:In the initial stage of growth plate injury inflammation,platelet-derived growth factor BB promotes the repair of growth plate injury by promoting mesenchymal progenitor cell infiltration,chondrogenesis,osteogenic response,and regulating bone remodeling. OBJECTIVE:To elucidate the action mechanism of platelet-derived growth factor BB after growth plate injury. METHODS:PubMed,VIP,WanFang,and CNKI databases were used as the literature sources.The search terms were"growth plate injury,bone bridge,platelet-derived growth factor BB,repair"in English and Chinese.Finally,66 articles were screened for this review. RESULTS AND CONCLUSION:Growth plate injury experienced early inflammation,vascular reconstruction,fibroossification,structural remodeling and other pathological processes,accompanied by the crosstalk of chondrocytes,vascular endothelial cells,stem cells,osteoblasts,osteoclasts and other cells.Platelet-derived growth factor BB,as an important factor in the early inflammatory response of injury,regulates the injury repair process by mediating a variety of cellular inflammatory responses.Targeting the inflammatory stimulation mediated by platelet-derived growth factor BB may delay the bone bridge formation process by improving the functional activities of osteoclasts,osteoblasts,and chondrocytes,so as to achieve the injury repair of growth plate.Platelet-derived growth factor BB plays an important role in angiogenesis and bone repair tissue formation at the injured site of growth plate and intrachondral bone lengthening function of uninjured growth plate.Inhibition of the coupling effect between angiogenesis initiated by platelet-derived growth factor BB and intrachondral bone formation may achieve the repair of growth plate injury.

In October 2014,we conducted a community population-based cohort study on cognitive impairment in two villages in Huyi district of Xi'an.All the village residents aged 40 years and above received a face-to-face questionnaire survey and were followed up every two years for cognitive changes.In this special issue,we used this cohort data to explore the relationships between vascular risk factors and cognitive impairment,investigated the predictive value of plasma biomarkers for cognitive impairment,and the effects of vascular risk factors intervention on cognitive impairment.We believe these are important for comprehensively understanding the risk factors for cognitive impairment and guiding its prevention and treatment.

Objective Investigating the effect and mechanism of resveratrol on cardiac function in exercise-induced fatigue rats by regulating mitochondrial energy metabolism.Methods Forty-eight healthy male Sprague Dawley rats(6～8 weeks old)were selected and divided randomly into a blank control(C)group,resveratrol administration(R)group,exercise-induced fatigue(E)group,and exercise-induced fatigue+resveratrol administration group(ER)(n=12 rats per group).Rats in the E and ER groups were subjected to weight-bearing 5％of their body weight for 60 minutes each day and exercise for 6 days per week for 6 weeks.Rats in the R and ER groups received resveratrol 50 mg/kg by gavage,1 hour after exercise.The biochemical kit was used to detect the indicators of motor fatigue,myocardial injury and mitochondrial energy metabolism enzymes in rat myocardium.The mRNA expression levels of myocardial energy metabolism related regulatory factors were detected by real-time fluorescent quantitative PCR(RT-qPCR).Results Plasma levels of blood urea nitrogen(BUN)and creatine kinase(CK)were significantly increased in rats in group E compared with group C(P＜0.05,P＜0.05),CK-MB and cTnI activity were also significantly increased(P＜0.01,P＜0.05),while activity levels of myocardial cytochrome C oxidase(COX)and succinate dehydrogenase(SDH)were significantly reduced(P＜0.01,P＜0.05).mRNA expression levels of the mitochondrial energy metabolism-related genes silent information regulator 1(SIRT1),peroxisome proliferator-activated receptor γ coactivator 1-α(PGC-1α),and estrogen receptor-related receptor α(ERRα)were also significantly reduced(P＜0.01,P＜0.01,P＜0.01).Serum levels of BUN and CK were significantly decreased in the ER group compared with group E(P＜0.05,P＜0.05),while CK-MB and cTnI activities were significantly decreased(P＜0.05,P＜0.05),myocardial COX and SDH activities were significantly increased(P＜0.01,P＜0.05),and SIRT1,PGC-1α and ERRα mRNA levels were also significantly increased(P＜0.05,P＜0.01,P＜0.01).Conclusions Resveratrol can effectively activate the sirtuin 1/peroxisome proliferator-activated receptor γ coactivator 1α/estrogen-related receptor α signaling pathway,improve myocardial energy metabolism in exercise-fatigued rats,and protect against myocardial injury.

Objective By comparing the prevalence and mortality of dementia among rural people in Xi'an in 1997 and 2014 to clarify the epidemiological changes of dementia among rural people in the city over 17 years.Methods In 1997 and 2014,people aged 55 and above in villages in Xi'an were selected by random cluster sampling method,and face-to-face questionnaire survey was conducted by combining centralized and home visits.Dementia and its subtypes were diagnosed by"the three-step method";the changes of dementia prevalence and mortality were compared between the two surveys.Results The prevalence of dementia among rural residents aged 55 and above in Xi'an was 3.49％in 1997,with age-gender standardized prevalence of 2.08％.In 2014,the prevalence of dementia was 4.25％,with age-gender standardized prevalence of 2.78％.Over the 17 years,the prevalence of dementia increased by 1.79 times(OR=1.79,95％CI:1.20-2.65,P=0.004),with a 1.9-fold increase in females and a 1.67-fold increase in males.The mortality of dementia patients was 61.76‰ and age-gender standardized mortality was 60.20‰ in 1997,while the mortality was 35.71‰ and age-gender standardized mortality was 34.18‰ in 2014.The mortality of dementia decreased by 33％over the 17 years(HR=0.33,95％CI:0.15-0.74,P=0.007).Conclusion The prevalence of dementia in rural areas of Xi'an increased significantly over the 17 years,but the mortality rate decreased,and this trend was more obvious in women.

Objective To investigate the relationship between baseline serum lipid levels and cognitive decline after a 4-year follow-up in a cohort of middle-aged and elderly people in rural Xi'an.Methods The data were collected from the cognitive impairment cohort of middle-aged and elderly people in rural areas of Xi'an,Shaanxi Province.The cohort selected the population ≥40 years old in two villages of Huyi District,Xi'an,as the research subjects.The baseline survey was completed from October 2014 to March 2015,and two follow-up visits were conducted in 2016 and 2018.The Mini-Mental State Examination(MMSE)was applied to assess the overall cognitive function.The MMSE score dropping between the 2014 and 2018(△MMSE)≥2 points were defined as cognitive decline.Baseline lipid levels[total cholesterol(TC),triglyceride(TG),high-density lipoprotein cholesterol(HDL-c),low-density lipoprotein cholesterol(LDL-c)]were converted into three classification data based on 25％quantile and 75％quantile[Q1(≤25％)vs.Q2-Q3(25％-75％)vs.Q4(≥75％)],and using the Q2-Q3 group as the reference group.The relationship between serum lipid levels and cognitive decline at baseline was analyzed by multivariate Logistic regression.Interaction effect analysis and subgroup analysis were made to investigate the interaction effect of age(＜65 years vs.≥65 years)on the relationship between serum lipid and cognitive decline.Results There were 1 349 participants with complete baseline data,and 235(17.42％)were ≥65 years old at baseline;230 cases(17.05％)had cognitive decline.No significant association was found between TC,TG,LDL-c,HDL-c and cognitive decline in subgroups＜65 years of age.In the subgroup ≥65 years of age,the Q1(≤4.37 mmol/L)group of TC was not significantly associated with the risk of cognitive decline compared with the Q2-Q3(4.37-5.61 mmol/L)group of TC,but the Q,(≥5.61 mmol/L)group of TC was significantly associated withan increased risk of cognitive decline(OR=2.519,95％CI:1.217-5.214,P=0.013).Age had an interactive effect on the relationship between the Q4 group of TC and cognitive decline(OR=2.202,95％CI:1.111-4.363,P=0.024).Compared with the Q2-Q3(1.03-2.01 mmol/L)group of TG,the Q,(≤ 1.03 mmol/L)group of TG was associated with a lower risk of cognitive decline(OR=0.318,95％CI:0.120-0.838,P=0.020).Age had an interactive effect on the relationship between the Q1 group of TG and cognitive decline(OR=0.344,95％CI:0.132-0.896,P=0.029).However,there was no significant correlation between the Q4(≥2.01 mmol/L)group of TG and the risk of cognitive decline.Compared with the Q2-Q3(2.70-3.81 mmol/L)group of LDL-c,the Q1(≤ 2.70 mmol/L)group of LDL-c was not significantly associated with the risk of cognitive decline,but the Q4(≥3.81 mmol/L)group of LDL-c had significant association with an increased risk of cognitive decline(OR=2.367,95％CI:1.143-4.900,P=0.020).Age had an interactive effect on the relationship between the Q4 group of LDL-c and cognitive decline(OR=2.237,95％CI:1.134-4.415,P=0.020).No significant association was found between HDL-c and cognitive decline.Conclusion No significant association was found between HDL-c and cognitive decline at baseline.The relationship of TC,TG and LDL-c with cognitive decline was affected by age.Only in participants over 65 years old,the risk of cognitive decline was higher in those with high baseline levels of TC and LDL-c.Those with low baseline serum TG levels had a lower risk of cognitive decline.

Objective To investigate the relationship between type 2 diabetes mellitus(T2DM)and cognitive decline.Methods Data were obtained from the cognitive impairment cohort of middle-aged and elderly population in rural areas of Xi'an City.The cohort consisted of residents aged 40 years and older in two villages of Huyi District,Xi'an.The baseline survey was completed between October 2014 and March 2015,with two follow-up visits in 2016 and 2018.The present study was conducted on cognitively normal people at baseline.Individual characteristics,lifestyle,and medical history were collected;physical and biochemical examinations were completed.According to medical history of T2DM and fasting blood glucose,the study population was divided into non-T2DM group,pre-existing T2DM group,and new-onset T2DM group.The Mini-Mental State Examination(MMSE)was used to assess global cognitive function.Participants with a drop of≥2 points in MMSE score from baseline after 4 years were defined as having cognitive decline.Chi-square test and multivariate Logistic regression analysis were employed to analyze the effect of T2DM status on the risk of cognitive decline.Results A total of 1 350 subjects completed the follow-up.In the follow-up population,1 096(81.2％)were free of T2DM,158(11.7％)already had T2DM at baseline,and 96(7.1％)developed new-onset T2DM during the follow-up.Cognitive decline was observed in 230 individuals after 4 years,representing 17.0％of the study population.The new-onset T2DM group had the highest 4-year incidence of cognitive decline(non-T2DM group vs.pre-existing T2DM group vs.new-onset T2DM group:15.7％vs.20.9％vs.26.0％,P=0.014),and the incidence of cognitive decline in the newly-onset T2DM group was significantly higher than that in the non-T2DM group(P=0.009).Multivariate Logistic regression analysis showed that the new-onset T2DM group had an increased risk of cognitive decline compared with the non-T2DM group within 4 years(OR=1.726,95％CI:1.029-2.896,P=0.039).However,no significant difference in 4-year risk of cognitive decline in the pre-existing T2DM group was observed(OR=1.402,95％CI:0.890-2.210,P=0.145).Conclusion Through the 4-year follow-up study of cognitively normal adults aged 40 and above in rural Xi'an,it was found that new-onset T2DM patients face a significantly elevated risk of cognitive decline,suggesting that cognitive decline may occur in the early stage of T2DM.

Objective To explore the relationship between plasma amyloid-β(Aβ)and cognitive impairment.Methods A total of all villagers(aged 40 years and above)from two villages of Xi'an,China,were enrolled.A validated Chinese version of the Mini-Mental State Examination and neuropsychological battery were used to assess cognition.Levels of fasting plasma Aβ1-42 and Aβ1-40 were tested using commercial enzyme-linked immunosorbent assay(ELISA).Relationship between plasma Aβ and cognitive impairment was analyzed using Logistic regression analysis.Results Of the 1 314 enrolled subjects,1 180(89.80％)had normal cognition,85(6.47％)had suspected cognitive impairment,and 49(3.73％)had probable cognitive impairment.Univariate analysis showed that plasma Aβ1-42/Aβ1-40 ratio was higher in the suspected cognitive impairment group than in the probable cognitive impairment group(P＜0.05)and normal cognitive group(P＜0.05);plasma Aβ1-42 level in the suspected cognitive impairment group was higher than that in normal cognitive group(P＜0.05).The level of Aβ1-40 did not differ between the three groups.After correcting for confounding factors(including age,gender,degree of education,cognitive impairment risk factors,habits of living)in the multivariate Logistic regression analysis,the results were consistent with those in the univariate analysis.Conclusion Levels of plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio were elevated in patients with suspected cognitive impairment,indicating that elevated plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio may be more pronounced in early stage of cognitive impairment.They may be early biomarkers for cognitive impairment,which can help identify and intervene the disease earlier.

Objective To investigate the relationship between plasma homocysteine(Hcy)levels and cognitive impairment(CI).Methods From November 2018 to January 2019,baseline data and cognitive function were collected from the participants aged≥40 years who lived in two villages in Huyi District,Xi'an,China.Their global cognitive function was assessed by Mini-Mental State Examination(MMSE)and the diagnosis of cognitive impairment was based on international guidelines.Fasting blood was collected in the morning,and plasma Hcy level was measured by the chemiluminometric assay.Multivariate Logistic regression analysis,subgroup analysis,and interaction analysis were performed to investigate the relationship between plasma Hcy and CI.Results A total of 1 805 subjects were included in the analysis.There were 1 056 females(58.5％),age ranged from 40 to 88 years[mean(58.99±9.52)years],and 145 participants(8.0％)were diagnosed as CI.The median plasma Hcy level in the overall population was 14.1(11.6,17.8)μmol/L.There were 729(40.4％)subjects in the HHcy group(＞15.0 μmol/L)and 1 076(59.6％)in the normal group(≤15.0 μmol/L).Univariate analysis showed that the prevalence of CI was higher in the HHcy group than in the normal Hcy group(11.4％vs.5.8％,P＜0.001).In multivariable Logistic regression fully adjusted for potential confounders,each 1 μmol/L increase in plasma Hcy level was associated with a 3.0％increased risk of CI(OR=1.030,95％CI:1.012-1.048,P=0.001).Interaction analysis indicated that sex,age,BMI,systolic blood pressure,history of stroke,and diabetes did not significantly modify this association.Conclusion Elevated plasma Hcy levels are associated with an increased risk of CI in people aged≥40 years.This indicates that HHcy may be a risk factor for CI.