Exploring non-invasive diagnostics for metabolic dysfunctionassociated fatty liver disease

The population with metabolic dysfunction-associated fatty liver disease(MAFLD)is increasingly common worldwide.Identification of people at risk of progression to advanced stages is necessary to timely offer interventions and appropriate care.Liver biopsy is currently considered the gold standard for the diagnosis and staging of MAFLD,but it has associated risks and limitations.This has spurred the exploration of non-invasive diagnostics for MAFLD,especially for steatohepatitis and fibrosis.These non-invasive approaches mostly include biomarkers and algorithms derived from anthropometric measurements,serum tests,imaging or stool metagenome profiling.However,they still need rigorous and widespread clinical validation for the diagnostic performance.

FibroScan-aspartate transaminase:A superior non-invasive model for diagnosing high-risk metabolic dysfunction-associated steatohepatitis

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)with hepatic histological NAFLD activity score≥4 and fibrosis stage F≥2 is regarded as“at risk”non-alcoholic steatohepatitis(NASH).Based on an international consensus,NAFLD and NASH were renamed as metabolic dysfunction-associated steatotic liver disease(MASLD)and metabolic dysfunction-associated steatohepatitis(MASH),respectively;hence,we introduced the term“high-risk MASH”.Diagnostic values of seven non-invasive models,including FibroScan-aspartate transaminase(FAST),fibrosis-4(FIB-4),aspartate transaminase to platelet ratio index(APRI),etc.for high-risk MASH have rarely been studied and compared in MASLD.AIM To assess the clinical value of seven non-invasive models as alternatives to liver biopsy for diagnosing high-risk MASH.METHODS A retrospective analysis was conducted on 309 patients diagnosed with NAFLD via liver biopsy at Beijing Ditan Hospital,between January 2012 and December 2020.After screening for MASLD and the exclusion criteria,279 patients wereincluded and categorized into high-risk and non-high-risk MASH groups.Utilizing threshold values of each model,sensitivity,specificity,positive predictive value(PPV),and negative predictive values(NPV),were calculated.Receiver operating characteristic curves were constructed to evaluate their diagnostic efficacy based on the area under the curve(AUROC).RESULTS MASLD diagnostic criteria were met by 99.4%patients with NAFLD.The MASLD population was analyzed in two cohorts:Overall population(279 patients)and the subgroup(117 patients)who underwent liver transient elastography(FibroScan).In the overall population,FIB-4 showed better diagnostic efficacy and higher PPV,with sensitivity,specificity,PPV,NPV,and AUROC of 26.9%,95.2%,73.5%,72.2%,and 0.75.APRI,Forns index,and aspartate transaminase to alanine transaminase ratio(ARR)showed moderate diagnostic efficacy,whereas S index and gamma-glutamyl transpeptidase to platelet ratio(GPR)were relatively weaker.In the subgroup,FAST had the highest diagnostic efficacy,its sensitivity,specificity,PPV,NPV,and AUROC were 44.2%,92.3%,82.1%,67.4%,and 0.82.The FIB-4 AUROC was 0.76.S index and GPR exhibited almost no diagnostic value for high-risk MASH.CONCLUSION FAST and FIB-4 could replace liver biopsy as more effectively diagnostic methods for high-risk MASH compared to APRI,Forns index,ARR,S index,and GPR;FAST is superior to FIB-4.

Functional near-infrared spectroscopy in non-invasive neuromodulation

Non-invasive cerebral neuromodulation technologies are essential for the reorganization of cerebral neural networks,which have been widely applied in the field of central neurological diseases,such as stroke,Parkinson’s disease,and mental disorders.Although significant advances have been made in neuromodulation technologies,the identification of optimal neurostimulation paramete rs including the co rtical target,duration,and inhibition or excitation pattern is still limited due to the lack of guidance for neural circuits.Moreove r,the neural mechanism unde rlying neuromodulation for improved behavioral performance remains poorly understood.Recently,advancements in neuroimaging have provided insight into neuromodulation techniques.Functional near-infrared spectroscopy,as a novel non-invasive optical brain imaging method,can detect brain activity by measuring cerebral hemodynamics with the advantages of portability,high motion tole rance,and anti-electromagnetic interference.Coupling functional near-infra red spectroscopy with neuromodulation technologies offe rs an opportunity to monitor the cortical response,provide realtime feedbac k,and establish a closed-loop strategy integrating evaluation,feedbac k,and intervention for neurostimulation,which provides a theoretical basis for development of individualized precise neuro rehabilitation.We aimed to summarize the advantages of functional near-infra red spectroscopy and provide an ove rview of the current research on functional near-infrared spectroscopy in transcranial magnetic stimulation,transcranial electrical stimulation,neurofeedback,and braincomputer interfaces.Furthermore,the future perspectives and directions for the application of functional near-infrared spectroscopy in neuromodulation are summarized.In conclusion,functional near-infrared spectroscopy combined with neuromodulation may promote the optimization of central pellral reorganization to achieve better functional recovery form central nervous system diseases.

Recent developments in non-invasive methods for assessing metabolic dysfunction-associated fatty liver disease

The prevalence of metabolic dysfunction-associated fatty liver disease(MAFLD)is increasing,affecting over one-third of the global population and contributing to significant morbidity and mortality.Diagnosing MAFLD,especially with advan-ced fibrosis,remains challenging due to the limitations of liver biopsy,the current gold standard.Non-invasive tests are crucial for early detection and management.Among these,the fibrosis-4 index(Fib-4)is widely recommended as a first-line test for screening for liver fibrosis.Advanced imaging techniques,including ultrasound-based elastography and magnetic resonance elastography,offer high accuracy but are limited by cost and availability.Combining biomarkers,such as in the enhanced liver fibrosis score and FibroScan-AST score,enhances diagnostic precision and is recommended to further stratify patients who are considered to be intermediate or high risk from the Fib-4 score.We believe that the future lies in the combined use of biomarkers to improve diagnostic accuracy.

Advances in the Research Application of Ultrasound Non-Invasive Stress-Strain Loop Technology in Cardiovascular Diseases

The ultrasound pressure-strain loop (PSL) technique is a non-invasive method of examining myocardial work, which takes into account the effect of cardiac afterload on deformation and combines the overall longitudinal strain force of the left ventricle with the changes in the left ventricular pressure, allowing earlier detection of possible subclinical cardiac damage in patients, and a more accurate and non-invasive assessment of the patient’s myocardial work performance. In this article, we will discuss the progress of PSL applications in cardiovascular diseases.

Ensemble for evaluating diagnostic efficacy of non-invasive indices in predicting liver fibrosis in untreated hepatitis C virus population

BACKGROUND Hepatitis C virus(HCV)infection progresses through various phases,starting with inflammation and ending with hepatocellular carcinoma.There are several invasive and non-invasive methods to diagnose chronic HCV infection.The invasive methods have their benefits but are linked to morbidity and complications.Thus,it is important to analyze the potential of non-invasive methods as an alternative.Shear wave elastography(SWE)is a non-invasive imaging tool widely validated in clinical and research studies as a surrogate marker of liver fibrosis.Liver fibrosis determination by invasive liver biopsy and non-invasive SWE agree closely in clinical studies and therefore both are gold standards.AIM To analyzed the diagnostic efficacy of non-invasive indices[serum fibronectin,aspartate aminotransferase to platelet ratio index(APRI),alanine aminotransferase ratio(AAR),and fibrosis-4(FIB-4)]in relation to SWE.We have used an Artificial Intelligence method to predict the severity of liver fibrosis and uncover the complex relationship between non-invasive indices and fibrosis severity.METHODS We have conducted a hospital-based study considering 100 untreated patients detected as HCV positive using a quantitative Real-Time Polymerase Chain Reaction assay.We performed statistical and probabilistic analyses to determine the relationship between non-invasive indices and the severity of fibrosis.We also used standard diagnostic methods to measure the diagnostic accuracy for all the subjects.RESULTS The results of our study showed that fibronectin is a highly accurate diagnostic tool for predicting fibrosis stages(mild,moderate,and severe).This was based on its sensitivity(100%,92.2%,96.2%),specificity(96%,100%,98.6%),Youden’s index(0.960,0.922,0.948),area under receiver operating characteristic curve(0.999,0.993,0.922),and Likelihood test(LR+>10 and LR-<0.1).Additionally,our Bayesian Network analysis revealed that fibronectin(>200),AAR(>1),APRI(>3),and FIB-4(>4)were all strongly associated with patients who had severe fibrosis,with a 100% probability.CONCLUSION We have found a strong correlation between fibronectin and liver fibrosis progression in HCV patients.Additionally,we observed that the severity of liver fibrosis increases with an increase in the non-invasive indices that we investigated.

A Study on Near-Infrared Non-Invasive Blood Glucose Concentration Regression Prediction Based on PSO-MKL-SVR

To improve the accuracy of predicting non-invasive blood glucose concentration in the near-infrared spectrum, we utilized the Particle Swarm Optimization (PSO) algorithm to optimize hyperparameters for the Multi-Kernel Learning Support Vector Machine (MKL-SVR). With these optimized hyperparameters, we established a non-invasive blood glucose regression model, referred to as the PSO-MKL-SVR model. Subsequently, we conducted a comparative analysis between the PSO-MKL-SVR model and the PSO-SVR model. In a dataset comprising ten volunteers, the PSO-MKL-SVR model exhibited significant precision improvements, including a 16.03% reduction in Mean Square Error and a 0.29% increase in the Squared Correlation Coefficient. Moreover, there was a 0.14% higher probability of the Clark’s Error Grid Analysis falling within Zone A. Additionally, the PSO-MKL-SVR model demonstrated a faster operational speed compared to the PSO-SVR model.

Observation on the Effect of Non-Invasive Ventilator Combined with Conventional Therapy in the Treatment of Chronic Obstructive Pulmonary Disease Complicated with Respiratory Failure

Objective:To explore the clinical effect of a non-invasive ventilator combined with conventional therapy in the treatment of patients with chronic obstructive pulmonary disease(COPD)combined with respiratory failure.Methods:68 patients with COPD combined with respiratory failure treated in our hospital from September 2021 to October 2023 were selected as the research subjects.Using the random number table method,they were divided into a control group and an experimental group of 34 cases each.The control group received conventional symptomatic treatment,and the experimental group received non-invasive ventilator treatment based on the control group.The clinical effects,blood gas indicators(partial pressure of carbon dioxide(PaCO_(2)),partial pressure of oxygen(PaO_(2)),arterial oxygen saturation(SaO_(2))),lung function(forced expiratory volume in 1 second(FEV1),forced vital capacity(FVC),6 min walking distance),complications,and inflammatory factor levels(c-reactive protein(CRP),interleukin-6(IL-6),neutrophil-to-lymphocyte ratio(NLR))of the two groups of patients were observed.Results:(1)The clinical efficacy of the patients in the experimental group(33/97.06%)was more significant as compared with the control group(25/73.53%)(P<0.05);(2)After treatment,the clinical efficacy of the two groups of patients in terms of FEV1,FEV1/FVC,6-minute walking distance,PaO_(2)and SaO_(2)all increased in the experimental group as compared to that of the control group(P<0.05);(3)After treatment,the PaCO_(2),CRP,IL-6,and NLR of the two groups of patients decreased,and the decrease in the experimental group was higher than that of the control group(P<0.05);(4)The patients’complication rate in the experimental group(2/5.88%)was lower as compared to that of the control group(9/26.46%)(P<0.05).Conclusion:Non-invasive ventilators combined with conventional therapy achieved good clinical results in treating patients with COPD and respiratory failure.

Analysis of the Effect of Non-Invasive Positive Pressure Ventilation in Emergency Treatment of Severe Bronchial Asthma with Respiratory Failure

Objective:This study aims to evaluate the clinical efficacy of non-invasive positive pressure ventilation(NIPPV)in patients with severe bronchial asthma combined with respiratory failure.Methods:90 patients with severe bronchial asthma combined with respiratory failure between September 2022 and December 2023 were selected for the study and randomly divided into the experimental group(NIPPV-assisted treatment)and the control group.The differences between the two groups were compared in terms of total effective rate of treatment,days of clinical symptom disappearance,days of hospitalization,lung function indexes,incidence of adverse reactions,and quality of life.Results:Patients in the experimental group had a significantly higher total effective rate of treatment(97.78%)than the control group(75.56%).In terms of pulmonary function indexes,patients in the experimental group showed significant improvement after treatment,especially the increase in forced expiratory volume and forced vital capacity,while these improvements were not as obvious in the control group.In addition,the incidence of adverse reactions was significantly lower in the experimental group than in the control group,suggesting that the application of NIPPV is relatively safe.Quality of life assessment also showed that patients in the experimental group had significantly better quality of life than the control group after treatment.Conclusion:This study demonstrated the effectiveness of NIPPV as an adjunctive treatment for severe bronchial asthma combined with respiratory failure.NIPPV can improve lung function,reduce the incidence of adverse effects,increase the overall effectiveness of the treatment,and contribute to the improvement of patients'quality of life.Therefore,NIPPV should be regarded as an effective and safe treatment in clinical management,especially in patients with severe bronchial asthma combined with respiratory failure,where its application has potential clinical significance.

Relationship Between Gene-Phenotype and Clinical Manifestations of Chromosomal Copy Number Variations Indicated by Non-Invasive Prenatal Testing

Objective:To analyze the clinical value of non-invasive prenatal testing(NIPT)in detecting chromosomal copy number variations(CNVs)and to explore the relationship between gene expression and clinical manifestations of chromosomal copy number variations.Methods:3551 naturally conceived singleton pregnant women who underwent NIPT were included in this study.The NIPT revealed abnormalities other than sex chromosome abnormalities and trisomy 13,18,and 21.Pregnant women with chromosome copy number variations underwent genetic counseling and prenatal ultrasound examination.Interventional prenatal diagnosis and chromosome microarray analysis(CMA)were performed.The clinical phenotypes and pregnancy outcomes of different prenatal diagnoses were analyzed.Additionally,a follow-up was conducted by telephone to track fetal development after birth,at six months,and one year post-birth.Results:A total of 53 cases among 3551 cases showed chromosomal copy number variation.Interventional prenatal diagnosis was performed in 36 cases:27 cases were negative and 8 were consistent with the NIPT test results.This indicates that NIPT’s positive predictive value(PPV)in CNVs is 22.22%.Conclusion:NIPT has certain clinical significance in screening chromosome copy number variations and is expected to become a routine screening for chromosomal microdeletions and microduplications.However,further interventional prenatal diagnosis is still needed to identify fetal CNVs.

Revolutionizing Non-Invasive Biomarker Discoveries: The Power of Methylation Screening Analysis in Cell-Free DNA Liquid Biopsy

Epigenetic changes of DNA, including methylation, have long been recognized as key indicators of various diseases, including aging, cancer, and neurological disorders. Biomarker discoveries based on distinct methylation patterns for both hypermethylation and hypomethylation lead the way in discovery of novel diagnosis and treatment targets. Many different approaches are present to detect the level of methylation in whole genome (whole genome bisulfite sequencing, microarray) as well as at specific loci (methylation specific PCR). Cell-free DNA (cf-DNA) found in body fluids like blood provides information about DNA methylation and serves as a less invasive approach for genetic screening. Cell-free DNA and methylation screening technologies, when combined, have the potential to transform the way we approach genetic screening and personalized therapy. These technologies can help enhance disease diagnostic accuracy and inform the development of targeted therapeutics by providing a non-invasive way for acquiring genomic information and identifying disease-associated methylation patterns. We highlight the clinical benefits of using cell-free DNA (cf-DNA) liquid biopsy analysis and available methylation screening technologies that have been crucial in identifying biomarkers for disease from patients using a non-invasive way. Powering such biomarker discoveries are various methods of cf-DNA methylation analysis such as Bisulfite Sequencing and most recently, Methylation-Specific Restriction Enzyme (MSRE-seq) Analysis, paving the way for novel epigenetic biomarker discoveries for more robust diagnosis such as early disease detection, prognosis, monitoring of disease progression and treatment response as well as discovery of novel drug targets.

HBsAg ELISA+/HBV DNA NAT-献血者血清学与分子生物学特征分析

目的 了解西安地区无偿献血人群HBsAg ELISA检测结果与HBV DNA检测结果不一致的标本相关血清学标志物的分布情况。方法 收集2022年11月1日—2023年4月30日陕西省血液中心HBsAg ELISA+/HBV DNA NAT-(ELISA+/NAT-)标本共计71份,对其采用电化学发光法检测乙肝血清学标志物,同时复检巢式PCR扩增HBV S区和C区基因片段。结果 双ELISA+/NAT-标本(n=30)巢式PCR检测阳性率远高于单ELISA+/NAT-标本(n=41)(60%vs 24.40%,P<0.05)。前者献血者100%为初次献血者,血清抗-HBc阳性率100%,血清学模式以1、4、5此3项阳性(80%)为主;后者献血者中31.7%为重复献血者,血清抗-HBc阳性率仅为19.51%,血清学模式以单2项阳性(43.90%)和全阴(36.58%)为主。结论 单ELISA+结果存在较多假阳性,导致不必要的血液报废;而NAT-标本可能存在低水平的HBV DNA,产生漏检风险。建议针对单HBsAg ELISA+/NAT-献血者,采用多套系统多种方法追溯检测,提高献血者HBV筛查的准确度,减少不必要的血液浪费。

中年男性精子DNA碎片率对体外受精-胚胎移植妊娠结局的影响

目的探讨中年男性精子DNA碎片率(DFI)与精液质量和体外受精-胚胎移植妊娠结局的关系。方法共收集180例接受常规体外受精-胚胎移植治疗且男性年龄>38岁的精液标本。根据DFI的阈值分成(<30%和≥30%)两组。主要测量指标包括:常规精液参数、激素水平、DFI、受精率、优质胚胎率、临床妊娠率等。结果通过比较分析发现,DFI与男性卵泡刺激素(FSH)、精子活力、精子形态密切相关,且精子活力随着DFI水平的升高而下降(P<0.05);当DFI≥30%时,优质胚胎率下降(P<0.05),但两组的临床妊娠率差异无显著性(P>0.05)。结论DFI可以作为中年男性精液常规分析的重要参考指标,虽然DFI影响优质胚胎率,但与辅助生殖治疗的临床妊娠结局无关。

完带汤防治脾虚湿盛型外阴阴道假丝酵母菌病的临床疗效及对DNA损伤的影响

目的探讨完带汤治疗脾虚湿盛型外阴阴道假丝酵母菌病(Vulvovaginal candidiasis,VVC)的临床疗效及对DNA损伤的影响。方法将符合纳入标准的70例脾虚湿盛VVC患者随机分为完带汤组和氟康唑组各35例,治疗期间2组各脱落5例。氟康唑组采用150 mg氟康唑口服一次;完带汤组采用完带汤口服14 d。治疗后比较2组患者中医证候积分变化情况;评估2组患者临床治愈(Test of cure,TOC)率及临床缓解(Clinical improvement,CI)率;比色法检测阴道灌洗液中8-羟基脱氧鸟苷(8-hydroxydeoxyguanosine,8-OHDG)水平变化以评估DNA损伤情况;治疗后3月评估患者访视临床完全缓解(Follow up,FU)、真菌学转阴及复发率。结果治疗后,2组患者中医证候积分均呈现不同程度改善(P<0.05,P<0.01);完带汤组优于氟康唑组(P<0.05,P<0.01);完带汤组TOC、CI、真菌学转阴率与氟康唑组未见明显差异(P>0.05);但完带汤组FU及复发率均显著优于氟康唑组(P<0.05,P<0.01)。治疗后,氟康唑组阴道灌洗液中8-OHDG表达显著增加(P<0.001),完带汤组未见明显变化,显著低于氟康唑组(P<0.001)。结论完带汤总体临床疗效与氟康唑相当,但在改善中医证候、防止复发方面优于氟康唑,同时具有不加剧阴道细胞DNA损伤的优势。

不同运动方式对人体DNA损伤、DNA甲基化和端粒长度的影响

背景:运动不仅是改善身体健康和心理健康的有效手段,还对代谢性和心脑血管等疾病的发生、发展具有良好的干预效果,其原因与表观遗传因素有关。目的:总结不同运动方式对人体DNA损伤、DNA甲基化和端粒长度的影响,并分析运动调控表观遗传修饰的可能机制,以期为运动改善机体功能提供参考。方法:以“运动,有氧训练,急性运动,无氧训练,抗阻训练,DNA损伤,DNA甲基化,端粒”为中文检索词,以“exercise,sport,aerobic exercise,anaerobic exercise,resistance training,acute exercise,DNA methylation,DNA damage,telomere”为英文检索词。在PubMed、Embase、Web of Science、中国知网数据库中进行检索,并根据纳入与排除标准筛选文献,最终纳入70篇文献。结果与结论:①长期有氧、抗阻和无氧运动均能改善DNA损伤,其原因与运动可以提高机体的抗氧化能力有关。而急性运动则会通过上调活性氧和活性氮氧化物的表达进而加剧DNA损伤程度;②急性运动、长期抗阻运动和无氧运动在降低DNA甲基化方面具有积极作用,其关键机制可能是运动诱导的活性氧使氧化型谷胱甘肽/还原型谷胱甘肽比值和DNA甲基化转移酶、10-11易位酶的表达发生了改变,进而对DNA甲基化产生调控作用;③与其他运动形式相比,长时间有氧运动可能更具有增加端粒长度的潜在价值,其中的生物学机制涉及炎症、氧化应激、DNA甲基化和微小RNA的表达调控;④基于当前文献可知,有氧运动持续2年以上可以增加端粒长度,未来的研究也应进一步明确最佳的运动持续时间。

基于混沌理论与DNA动态编码的卫星图像加密算法

针对卫星图像在传输、存储过程中涉及的信息安全问题,该文提出一种新型的基于混沌理论与DNA动态编码的卫星图像加密算法。首先,提出一种改进型无限折叠混沌映射,拓宽了原有无限折叠混沌映射的混沌区间。之后,结合改进型Chebyshev混沌映射与SHA-256哈希算法,生成加密算法的密钥流,提升算法的明文敏感性。然后,利用混沌系统的状态值对Hilbert局部置乱后的像素进行DNA编码,实现DNA动态编码,解决了DNA编码规则较少所带来的容易受到暴力攻击的弱点。最后,使用混沌序列完成进一步混沌加密,从而彻底混淆原始像素信息,增加加密算法的随机性与复杂性,得到密文图像。实验结果表明,该算法具有较好的加密效果和应对各种攻击的能力。

环境DNA技术发展及其在长江流域水生生态学领域的应用研究进展

长江流域鱼类资源丰富、生物多样性高。近年来,受人为干扰、环境变化等因素影响,鱼类资源急剧衰退,全面了解该流域水生生态学信息、进行长江大保护迫在眉睫。随着分子生物学技术的发展,环境DNA技术应运而生,其相比于传统调查方式更加高效、灵敏,应用领域更广;该技术的灵敏性使其非常适合于检测濒危物种、低密度物种入侵、瞬时和隐秘物种的存在,特别是当检测低密度物种的采样工作难以控制时,其敏感性、简便性和降低危害性的优势愈加显现出来。因此,该技术已被广泛应用于食品微生物、生物监测、群落生态学、古环境、保护生物学和生物入侵等领域的研究。介绍了环境DNA定义、发展史、研究方法与优劣势,在此基础上概述了其在长江流域水生生态学领域的应用研究进展,最后展望了环境DNA技术与环境RNA技术相结合的技术革新以及新一代测序手段、大数据及机器智能技术多技术结合助力该领域研究的前景,以期为长江流域持续性生态学监测提供借鉴和参考。

DNA条形码技术在蛇类鉴别中的应用

从NCBI中GenBank数据库下载蛇类细胞色素b基因(Cytb)序列7329条,以MT765098.1序列为标准进行对比和修剪,获得蛇类Cytb序列4665条。对蛇类Cytb序列进行核苷酸饱和度、遗传多样性、种内和种间遗传距离计算,构建系统发育树。结果表明,基于Kimura–2–Parameter模型,蛇类平均种内遗传距离为3.3%,普遍小于6.7%,而平均种间遗传距离为19.96%,普遍高于9.3%,说明蛇类物种间遗传距离存在较大差异。根据蛇类物种间遗传距离,识别出蛇类23个物种的亚种,Pareas和Hydrophis属物种含有复合体,Atractus dunni、A.iridescen和A.occidentali互为姐妹物种。

围绕FFPE样本特性的DNA纯化纳米磁珠优化

目的 探讨围绕福尔马林固定石蜡包埋(formalin fixed paraffin embedded, FFPE)样本特性获取更高质量/得率的纳米磁珠核酸提取方案,改进分子病理技术。方法 合成4大类15个小类的备选磁珠,以FFPE样本为中心,筛选高质量/得率磁珠。模拟常规组织、粗针穿刺(肝脏)、纤维支气管镜样本(肺),装管相同张数连片。采用筛选的最佳磁珠与市场出售的常见磁珠试剂提取核酸,横向对比纯化总量、片段大小等质量参数。应用PCR和Sanger验证核酸的下游应用。结果 以FFPE样本DNA为中心筛选自制纳米磁珠,获得最佳性能纳米磁珠总回收率为58.5%±1.58%,5种市售商品化磁珠和3种国产磁珠总回收率为18.68%~40.71%。相同组织量(连片)提取的DNA总量,在模拟常规组织、粗针穿刺和纤维支气管镜样本核酸得率比市售试剂盒提高39.49%~181.72%(P<0.05)。模拟纤维支气管镜样本1张(4μm)总量可达100 ng以上、5张总量可达400 ng以上。结论 以FFPE样本DNA为中心筛选的DNA纯化纳米磁珠,与商品化磁珠相比有较大提升,为临床分子病理检测的质量保证、自动化检测和项目拓展提供空间。

基于环境DNA技术的珠江中下游鱼类多样性初步研究

通过环境DNA技术(Environmental DNA,eDNA)检测珠江中下游鱼类生物多样性,探索珠江中下鱼类多样性监测和保护的新途径。2023年2月在珠江中下游设置了桂平、藤县、封开、德庆、肇庆和九江共6个采样点,通过水样采集及过滤、eDNA提取、遗传标记扩增及测序和数据库比对分析等流程检测鱼类多样性。结果表明,6个采样点共检测出30种鱼类,隶属于4目10科27属,其中土著鱼类26种,外来种4种。较已有传统调查数据新检出2种鱼类:美丽沙鳅(Botia pulchra)和齐氏罗非鱼(Oceochromis zillii)。鱼类优势种为子陵吻鰕虎鱼(Rhinogobius giurinus)、瓦氏黄颡鱼(Pelteobagrus vachellii)、鲢(Hypophthalmichthys molitrix)、尼罗罗非鱼(O.nilotica)、齐氏罗非鱼、南方波鱼(Rasbora steineri)和鲤(Cyprinus carpio)。根据Shannon指数和Simpson指数显示,eDNA检测九江和桂平站点的鱼类多样性最高,藤县的最低。作为一种新的检测方法,eDNA技术可用于快速检测珠江中下游鱼类的多样性及分布,在实际应用中可将eDNA技术与传统的监测方法相结合,以提供更全面的鱼类生物多样性数据信息。