三角褐指藻在多波长下藻液吸光度与细胞密度的关系研究

目的研究具潜在药用价值的三角褐指藻Phaeodactylum tricornutum在不同波长下,其藻液吸光度与细胞密度的关系。方法取对数生长后期的三角褐指藻藻液进行梯度稀释,利用显微镜观测微藻细胞密度,利用分光光度计分别测定藻液在8个波长下的吸光度,分析各波长下微藻细胞密度与吸光度的相关性。结果 6个稀释梯度下的细胞密度分别为923×104、453×104、207×104、94×104、47×104、22×104个/mL;不同波长下藻液吸光度有差别。8个波长下,细胞密度与吸光度均存在显著性相关关系,在680、663、420和450 nm波长处相关系数r值较大,分别为0.999 0、0.998 1、0.997 2和0.996 3。结论利用吸光度法检测三角褐指藻细胞生长是一种快速、简便、可行的方法;本试验条件下,在680、663、420和450 nm波长处测定三角褐指藻藻液的吸光度较为适宜。     

4株经济海洋微藻细胞生长的实验室研究

目的研究角毛藻Chaetocerossp．、绿色巴夫藻Pavlovaviridis、叉鞭金藻Dirateriainornate和杜氏盐藻Dunaliella salina4株经济海洋微藻的细胞生长特性,为微藻在医药学相关行业的开发与应用提供参考依据。方法采用室内实验方法,以添加f／2营养液的人工海水为培养介质,在植物培养箱中利用三角瓶进行微藻培养试验,测定微藻细胞密度,并计算细胞生长速率。结果4株经济海洋微藻的细胞生长呈现明显的缓慢期、快速期和平稳期阶段。角毛藻、绿色巴夫藻、叉鞭金藻和杜氏盐藻的最大细胞密度有明显差别,分别为6．71×10^6、4．916×10^7、1．225×10^7和4．64×10^6个／mL。对4株微藻在1—5d、5～9d、9～13d和13～17d几个时间段的生长速率进行比较分析,结果表明角毛藻、绿色巴夫藻、叉鞭金藻的生长速率在1～5d阶段最大,分别为0．57、0．48、0．55／d;而杜氏盐藻的生长速率在5～9d阶段最大,为0．68／d。结论实验选用的4株海洋微藻的细胞生长特征存在一定异同,在选育微藻株系开展微藻开发利用研究时应该考虑微藻细胞生长繁殖的差异性。     

邓老凉茶颗粒的HPLC指纹图谱及模式识别研究

目的 研究邓老凉茶颗粒的质量控制方法。方法 采用HPLC法建立了邓老凉茶颗粒甲醇提取液的HPLC指纹图谱,收集了不同批次的11批产品进行测定,并使用主成分分析法对指纹图谱进行了模式识别研究。结果 11批邓老凉茶颗粒指纹图谱相似度达到0.95以上;经主成分分析,16个共有峰可综合为3个主成分,其累积贡献率达91.89%,异绿原酸B的相对峰面积为邓老凉茶颗粒指纹图谱中影响最大的指标。结论 该方法稳定可靠,可以有效地用于邓老凉茶颗粒的质量评价和质量控制。     

胸部局限型Castleman病的CT诊断

目的:探讨胸部局限型Castleman病的临床、病理及CT表现.方法:回顾性分析10例经手术病理证实的胸部局限型Castleman病的病例资料.结果:10例患者中,病变位于前纵隔1例,后纵隔3例,中纵隔5例,左侧斜裂1例.CT表现:左侧斜裂病变平扫示中央区不规则钙化,增强呈不均匀中度强化;余9例病变平扫均呈均匀等密度影...     

Isolation and identification of tiger parvovirus in captive siberian tigers and phylogenetic analysis of VP2 gene

To better understand the prevalence and molecular epidemiology of parvovirus, this study reports the isolation and characterization of a tiger parvovirus (TPV) named CHJL-Siberian Tiger-01/2017 from a captive Siberian tiger in Jilin Province, China. A phylogenetic tree based on the full-length VP2 nucleotide sequence was constructed using the isolated strain in this study and 56 reference strains. The results showed that all the parvoviruses can be grouped into two large branches: the canine parvovirus (CPV) branch and the feline parvovirus (FPV) branch. FPV strains comprised TPVs, FPVs, blue fox parvoviruses (BFPVs), mink enteritis viruses (MEVs), and raccoon feline parvoviruses (RFPVs), and CPV strains comprised CPVs and raccoon dog parvoviruses (RDPVs). RFPVs are also often very closely related to those sampled from other carnivorous species, and raccoons may represent conduits for parvovirus transmission to other hosts. The results of amino acid changes in the VP2 protein of the isolated strain showed that amino acid Ile 101 was mutated to Thr (I 101T). Taken together, a field TPV strain CHJL-Siberian Tiger-01/2017 was isolated, which may be suitable for future studies on FPV infection, replication and vaccine development. This study provided new important findings about the evolution of parvovirus infection in tigers.     

Two new xyloketals from the endophytic fungus Endomelanconiopsis endophytica derived from medicinal plant Ficus hirta

Chemical examination of the liquid culture of Endomelanconiopsis endophytica A326 isolated from the Chinese folk medicine Ficus hirta resulted in the isolation of two new xyloketals named xyloketals K and L (1–2) and three known analogs (3–5) including a new natural product (5). Their structures were determined on the basis of extensive spectroscopic analysis. All compounds were evaluated for their cytotoxic activities against the SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. Nonetheless, no significant activity was observed.     

Dynamic biomechanical effect of lower body positive pressure treadmill training for hemiplegic gait rehabilitation after stroke: A case report

BACKGROUNDLower body positive pressure (LBPP) treadmill has potential applications for improving the gait of patients after stroke, but the related mechanism remains unclear.CASE SUMMARYA 62-year-old male patient suffered from ischemic stroke with hemiplegic gait. He was referred to our hospital because of a complaint of left limb weakness for 2 years. The LBPP training was performed one session per day and six times per week for 2 wk. The dynamic plantar pressure analysis was taken every 2 d. Meanwhile, three-digital gait analysis and synchronous electromyography as well as clinical assessments were taken before and after LBPP intervention and at the 4-wk follow-up. During LBPP training, our patient not only improved his lower limb muscle strength and walking speed, but more importantly, the symmetry index of various biomechanical indicators improved. Moreover, the patient’s planter pressure transferring from the heel area to toe area among the LBPP training process and the symmetry of lower body biomechanical parameters improved.CONCLUSIONIn this study, we documented a dynamic improvement of gait performance in a stroke patient under LBPP training, which included lower limb muscle strength, walking speed, and symmetry of lower limb biomechanics. Our study provides some crucial clues about the potential dynamic mechanism for LBPP training on gait and balance improvement, which is related to rebuilding foot pressure distribution and remodeling symmetry of biomechanics of the lower limb.     

Urine toxicology screening by liquid chromatography time-of-flight mass spectrometry in a quaternary hospital setting

ObjectiveValidation of a non-targeted method for urine drug screening (UDS) by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF), and comparison to an established GC–MS method in a hospital setting.Methods217 UDS specimens sent to a quaternary hospital pathology department, were analysed by a CEDIA® immunoassay screen (six drug panels; amphetamines, barbiturates, benzodiazepines, cocaine metabolites, cannabinoids and opiates) on an Abbott Architect instrument. Specimens were subsequently analysed by an established non-targeted qualitative GC–MS method and results compared with a general unknown screening method by LC-QTOF that was under evaluation as a replacement method.Results42 selected drugs were evaluated; limits of identification ranged from 2 to 100 µg/L and most drugs (n = 39) were stabile for 24 h after preparation. Matrix effects greater than 25% were observed in seven of the selected drugs. 87% of the specimens tested positive to 1 or more drug panels in a CEDIA® screen. A total of 537 positive drug findings were identified by GC–MS compared to 1,267 positive findings by LC-QTOF. On average, each GC–MS screen identified 2.5 ± 1.8 drugs and the LC-QTOF screen identified 5.8 ± 3.2 drugs. No drugs were identified in 11.3% of the GC–MS screens, whereas drugs were detected in 99% of these by the LC-QTOF. In almost all instances, the LC-QTOF screen could provide mass spectrometric confirmatory results of positive immunoassay screens and was able to identify a wider range of additional drugs and drug metabolites.ConclusionsThe described general unknown screening (non-targeted, qualitative) LC-QTOF method can detect a larger range of drugs encountered in a hospital setting. The method has been shown to be suitable for comprehensive toxicology screening in a clinical toxicology laboratory.     

Genome characteristics and molecular evolution of the human sapovirus variant GII.8

Human sapovirus is regarded as an important viral agent for acute diarrhea worldwide. GII.8, a recently reported genotype, has been detected in a few countries and regions. In this study, we obtained the first genome sequence of a sapovirus GII.8 strain isolated in mainland China, and comprehensively analyzed the genetic diversity and evolutionary process of this genotype. The viral genome of the new GII.8 Guangzhou strain GZ2014-L231 comprised 7433 nucleotides, including two ORFs. Pairwise alignments of the new genome with representative sequences of different genotypes showed inconsistent homology between different protein-encoding regions, of which NS1 and VP2 were found as the variable proteins, and NS3, NS5, and NS6/7 were found as the conserved ones. Compared with other reported GII.8 genomes, the Guangzhou strain introduced 34 new nucleotide changes and one new amino acid change. Phylogenetic analysis based on full-length VP1 sequences demonstrated that 11 GII.8 strains could be divided into 4 clusters A-D, with 88 SNP and 10 SAP spots occurred during their evolutionary process. The Guangzhou strain has higher homology with seven GII.8 strain detected after 2014, especially the US and Peruvian strains of 2015/2016, which have the identical VP1 amino acid sequences. Using a Bayesian coalescent method based on VP1 sequences, GII.8 was predicted to emerge in 2001 with the evolution rate of 1.45 × 10⁻³ nucleotide substitutions/site/year (strict clock). In summary, the data in this study not only provided reference data from mainland China for sapovirus researches in future, but also firstly described the evolutionary process of the GII.8 genotype.