A direct real-time polymerase chain reaction assay for rapid high-throughput detection of highly pathogenic North American porcine reproductive and respiratory syndrome virus in China without RNA purification

Background： Porcine reproductive and respiratory syndrome virus （PRRSV）, and particularly its highly pathogenic genotype （HP-PRRSV）, have caused massive economic losses to the global swine industry. Results： To rapidly identify HP-PRRSV, we developed a direct reaL-time reverse transcription polymerase chain reaction method （dRT-PCR） that could detect the virus from serum specimen without the need of RNA purification Our dRT-PCR assay can be completed in 1.5 h from when a sample is received to obtaining a result. Additionally, the sensitivity of dRT-PCR matched that of conventional reverse transcription PCR （cRT-PCR） that used purified RNA The lowest detection limit of HP-PRRSV was 6.3 TCIDs0 using dRT-PCR. We applied dRT-PCR assay to 144 field samples and the results showed strong consistency with those obtained by cRT-PCR. Moreover, the dRT-PCR method was able to tolerate 5-20% （v/v） serum. Conclusions： Our dRT-PCR assay allows for easier, faster, more cost-effective and higher throughput detection of HP-PRRSV compared with cRT-PCR methods. To the best of our knowledge, this is the first report to describe a real-time RT-PCR assay capable of detecting PRRSV in crude serum samples without the requirement for purifying RNA. We believe our approach has a great potential for application to other RNA viruses.

Using benzene carboxylic acids to prepare zirconium-based catalysts for the conversion of biomass-derived furfural

Benzene carboxylic acid (BCAs) are common and useful chemical blocks, which can be derived from the abundant low rank coals (LRCs) via oxidative degradation. In this work, we proposed a novel strategy to utilize BCAs as raw materials to prepare catalysts with transition metal zirconium, and the prepared catalysts were applied into the conversion of the renewable biomass resources. Typical model BCAs in the oxidative products of LRCs, including pyromellitic acid, trimesic acid (TMSA), trimellitic acid, and benzoic acid, were used as the block to construct the Zr- BCAs catalysts. The chemoselective conversion of furfural into furfuryl alcohol (FAL). an important reaction in the biomass conversion chain, is chosen to evaluate the activity of the catalysts. The preparation conditions of the catalysts and experiment factors during the reaction were systematically investigated. The prepared catalysts were characterized by SEM, TEM, XRD and TG-DTG. The results showed that the prepared catalysts were efficient for the conversion of furfural into FAL, among which Zr-TMSA gave the highest activity. Zr-TMSA could be recycled for ten times without obvious deactivation, indicating an excellent stability. The strategy proposed in this work may be beneficial for the value-added utilization of both LRCs and biomass resources.

Chemical composition and Pb(II)binding of dissolved organic matter in a hypersaline lake in China

Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquatic systems.The contributions of aquatic DOM to the environment and ecology of a system are closely related to its abundance and chemical structure.In this study,the chemical composition and binding properties of DOM in a hypersaline lake watershed were investigated for the fi rst time using dissolved organic carbon(DOC)analysis,absorption spectroscopy,Fourier transform infrared spectroscopy,pyrolysis-GC-MS(Py-GC-MS),and fl uorescence parallel factor(PARAFAC)analysis combined with Pb(II)titration techniques.The results showed that DOM from the tributaries that fl owed into the lake had a lower DOC content,higher molecular weight,and higher specifi c UV absorbance than the DOM in lake water.Protein-like fl uorophores were mainly found in tributary and lake surface water DOM(LSDOM)and humic-like substances were abundant in lake groundwater DOM(LGDOM).Using this multi-methodological approach,we found that the DOM from the hypersaline lake watershed was mainly from microbial origins,and consisted of aromatics,carbohydrates,and aliphatics.The results from quantitative analysis showed that DOM from the infl owing tributaries contained more aromatics,lower carbohydrates,and lower aliphatics than DOM in the lake.Monocyclic aromatic hydrocarbons and carbohydrates were more abundant in LSDOM than LGDOM.The results from the Pb(II)titration technique coupled with PARAFAC analysis suggested that PARAFAC-derived components had relatively low condition stability constants(log K_(M)<2).Of the two types of lake DOM,the LGDOM had a higher Pb(II)binding potential than the LSDOM.From this study we have improved our understanding of how DOM within a hypersaline lake watershed varies in its composition and potential to bind with metals.

胆汁酸在Barrett食管和食管腺癌发病中的作用

目的探讨胆汁酸在Barrett食管(BE)及食管腺癌(EAC)发病中的作用,为预防、治疗BE、EAC的发生提供参考依据。方法选取2017年8月10日至2020年10月30日于茌平区人民医院就诊,反流性疾病问卷评分>12分的患者,对其行无痛胃镜检查,镜下胃液留取及食管下段(胃食管结合部上1 cm处)黏膜组织活检,进行胃液、食管下段黏膜胆汁酸浓度检测。结果所检患者胃液中均检测到不同浓度的胆汁酸,且BE、EAC患者胃液及食管下段黏膜组织总胆汁酸浓度较非糜烂性反流病(NERD)、反流性食管炎(RE)患者胃液及食管下段黏膜组织总胆汁酸浓度明显升高(P值均<0.05)。结论胆汁酸在BE、EAC患者胃液及食管下段黏膜组织中的浓度较无Barrett食管的胃食管反流病患者的浓度明显升高,提示胆汁反流可能与胃食管结合部黏膜细胞恶性转化相关,抑制胆汁反流可能成为预防BE、EAC发生的必要干预措施。

Polyhydroxyalkanoates in tissue repair and regeneration

Developing advanced biocompatibility materials is of critical importance in biomedical engineering.Polyhydrox-yalkanoates(PHA),being famous for its flexible mechanical properties,thermal properties,biocompatibility,and biodegradability,has been widely used in wound dressings,artificial blood vessels,heart valves,nerve conduits,bone and cartilage scaffolds,surgical sutures,and other fields.However,reports on the application of PHA in tissue repair and regeneration are often lacking in systematics.Here,a comprehensive and in-depth perception of the performance advantages and application value of PHA is provided.In this review,the following applications of PHA in biomedical engineering are covered:i)soft tissue,ii)organ tissue,iii)vascular tissue,iv)heart valve tissue,v)nerve conduit tissue,vi)bone tissue,vii)cartilage tissue and viii)others.Finally,an outlook on the future research directions and challenges of PHA is presented.