不同症状类型苜蓿病毒病AMV病原检测及其寄主范围测定

为明确采自田间不同症状类型苜蓿病毒病病样中苜蓿花叶病毒(alfalfa mosaic virus,AMV)的带毒情况、症状表现与叶绿素含量的相关性及AMV的寄主范围,本试验通过田间调查采样、症状归类、丙酮乙醇混合液法和双抗体夹心酶联免疫吸附测定(DAS-ELISA)法对不同病样的叶绿素和AMV含量进行测定和检测,并对提纯至不同症状类型病样中AMV对9科32种植物的致病性进行测定。结果表明田间苜蓿病毒病病样有轻花叶、重花叶、叶片边缘褪绿黄化型和叶片畸形皱缩花叶矮化型4种症状类型,均带有AMV,且叶绿素含量、AMV含量与症状表现之间具有正相关性,症状表现最严重的叶片畸形皱缩花叶矮化型病样的叶绿素a、b、总叶绿素含量均比对照低58.00%以上,类胡萝卜素含量比对照高134.06%,AMV含量最高,为252.96 pg·mL^(-1);寄主范围测定表明AMV可侵染7科27种植物,对西葫芦致病性最强,症状表现为局部枯斑,30 d时AMV浓度为316.19 pg·mL^(-1)。

Establishment of Multiplex PCR for Simultaneous Detection of Four Venereal Pathogens

Venereal diseases are considered to be the most prevalent infectious diseases in the worldwide. China is now faced with a year-by-year increasing incidence of sexually transmitted diseases （STD）, which are spreading from high-risk groups to the general population. Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum and herpes simplex virus-2 （HSV-2） are always regarded as the most common venereal pathogens. The ＂golden standard＂ for testing Neisseria gonorrhoeae remains to be bacteria culture or microscopic examination.

Advances in Application of PCR Amplification in Etiologic Diagnosis

In recent years,with the rapid development of molecular biology diagnostic technology,many new polymerase chain reaction(PCR)technologies with high specificity and good sensitivity have gradually been developed.While expanding the range of detection methods,these technologies inevitably have some disadvantages.Therefore,in clinical pathogen diagnosis,medical personnel should choose the detection method according to the detection purpose and pathogen characteristics.In this paper,the basic principle,application scope,advantages and disadvantages and development of various emerging PCR diagnostic techniques are respectively described in order to provide a theoretical reference for the selection of pathogenic biological diagnostic techniques in the clinical practice.

Cationic conjugated polymers for detection and inactivation of pathogens

Conjugated polymers （CPs） are referred to a kind of fluorescent polymer materials with delocalized n-conjugated backbones. For the last decades, cationic CPs （CCPs） have been widely used in biosensor, imaging and biomedical fields due to their good photophysical properties and solubility in water medium resulting from side chain modification with ionized moieties. In this mini-review, we mainly introduced the applications of CCPs in detection and inactivation of pathogen with typical examples, and also briefly discussed the relevant mechanisms. We hold the expectation that this mini-review can offer researchers a general reference and inspire them to construct new systems with high performances of pathogen detection and antimicrobial activity.

Conjugated polymer materials for detection and discrimination of pathogenic microorganisms:Guarantee of biosafety

Infectious disease outbreaks have seriously endangered global health owing to the scarcity of testing materials and techniques.Diversified materials and methods should be urgently developed for rapid detection and discrimination of pathogenic microorganisms.Conjugated polymer(CP)materials are macromolecular compounds comprising numerous covalently bonded luminescent units.They have excellent light-harvesting and optical signal amplification capabilities owing to the transmission of excitation energy along their backbone.In recent years,CP materials have aroused research enthusiasm in the biosensors field because of their outstanding optoelectronic properties.This brief manuscript provides an overall review of recent progress achieved in CP-based systems for pathogen sensing.

The sound of blood:photoacoustic imaging in blood analysis

Blood analysis is a ubiquitous and critical aspect of modern medicine.Analyzing blood samples requires invasive techniques,various testing systems,and samples are limited to relatively small volumes.Photoacoustic imaging(PAI)is a novel imaging modality that utilizes non-ionizing energy that shows promise as an alternative to current methods.This paper seeks to review current applications of PAI in blood analysis for clinical use.Furthermore,we discuss obstacles to implementation and future directions to overcome these challenges.Firstly,we discuss three applications to cellular analysis of blood:sickle cell,bacteria,and circulating tumor cell detection.We then discuss applications to the analysis of blood plasma,including glucose detection and anticoagulation quantification.As such,we hope this article will serve as inspiration for PAI's potential application in blood analysis and prompt further studies to ultimately implement PAI into clinical practice.

Single stain hyperspectral imaging for accurate fungal pathogens identification and quantification

The most widely used method of identification of microbial morphology and structure is microscopy,but it can be difficult to distinguish between pathogens with a similar appearance.Existing fluorescent staining methods require a combination of a variety of fluorescent materials to meet this demand.In this study,unique concentration-dependent fluorescent carbon dots(CDs)were synthesized for the identification and quantification of pathogens.The emission wavelength of the CDs could be tuned spanning the full visible region by virtue of aggregation-induced narrowing of bandgaps.This tunable emission wavelength of the specific concentration response to diverse microbes can be used to distinguish microorganisms with a similar appearance,even in a same genus.A hyperspectral microscopy system was demonstrated to distinguish Aspergillus flavus and A.fumigatus based on the results above.The identification accuracy of the two similar-looking pathogens can be close to 100%,and the relative proportions and spatial distributions can also be profiled from the mixture of the pathogens.This technique can provide a solution to the fast detection of microorganisms and is potentially applicable to a wide range of problems in areas such as healthcare,food preparation,biotechnology,and health emergency.

Two-Photon Luminescence Imaging of Bacillus Spores Using Peptide-Functionalized Gold Nanorods

Bacillus subtilis spores(a simulant of Bacillus anthracis)have been imaged by two-photon luminescence(TPL)microscopy,using gold nanorods(GNRs)functionalized with a cysteine-terminated homing peptide.Control experiments using a peptide with a scrambled amino acid sequence confi rmed that the GNR targeting was highly selective for the spore surfaces.The high sensitivity of TPL combined with the high affi nity of the peptide labels enables spores to be detected with high fi delity using GNRs at femtomolar concentrations.It was also determined that GNRs are capable of signifi cant TPL output even when irradiated at near infrared(NIR)wavelengths far from their longitudinal plasmon resonance(LPR),permitting considerable fl exibility in the choice of GNR aspect ratio or excitation wavelength for TPL imaging.

An Efficient WRF Framework for Discovering Risk Genes and Abnormal Brain Regions in Parkinson's Disease Based on Imaging Genetics Data

As an emerging research field of brain science,multimodal data fusion analysis has attracted broader attention in the study of complex brain diseases such as Parkinson's disease(PD).However,current studies primarily lie with detecting the association among different modal data and reducing data attributes.The data mining method after fusion and the overall analysis framework are neglected.In this study,we propose a weighted random forest(WRF)model as the feature screening classifier.The interactions between genes and brain regions are detected as input multimodal fusion features by the correlation analysis method.We implement sample classification and optimal feature selection based on WRF,and construct a multimodal analysis framework for exploring the pathogenic factors of PD.The experimental results in Parkinson's Progression Markers Initiative(PPMI)database show that WRF performs better compared with some advanced methods,and the brain regions and genes related to PD are detected.The fusion of multi-modal data can improve the classification of PD patients and detect the pathogenic factors more comprehensively,which provides a novel perspective for the diagnosis and research of PD.We also show the great potential of WRF to perform the multimodal data fusion analysis of other brain diseases.

Rapid and specific identification of Fusarium pseudograminearum by qPCR based on RPB sequence

Fusarium crown rot,mainly caused by Fusarium pseudograminearum,is a destructive disease in wheat production.To establish a rapid and reliable detection method for F.peasudeograminearum,the specific PCR primer pair(Fpg-F1;R2)was designed based on the RPB sequence,and real-time fluorescence quantitative PCR(qPCR)was used to validate the efficiency of the primer.The results showed that the primer pair had high specificity and sensitivity of 100 pg of DNA.Furthermore,the qPCR system for early and rapid detection of F.peasudeograminearum had an amplification efficiency of 87.5%and correlation coefficient of 0.99,and the pathologic threshold of F.pseudograminearum in soil was determined by using this detection system.It was found that F.pseudograminearum could cause Fusarium crown rot when the DNA concentration of F.pseudograminearum in field soil exceeded 213 pg·g^(-1).Hence,the qPCR-based method we developed for F.pseudograminearum detection has the advantages of high specificity and sensitivity,and can be used for rapid and early detection of F.pseudograminearum even in field soils.