FQA, which uses the conservatism of plant species for particular habitats and the species richness of plant communities, is a rapid method for the assessment of habitat quality. This method is based on species composition of quadrats and coefficients of conservatism for species which assigned by experts. Floristic Quality Index (FQI) that reflects vegetation integrity and degradation of a site can be calculated by a simple formula and be used for space-time comparison of habitat quality. It has been widely used in more than ten countries including the United States and Canada. This paper presented the principle, calculation formulas and application cases of this method, with the aim to provide a simple, repeatable and comparable method to assess habitat quality for ecological managers and researchers.植物区系质量评价法(FQA)是一种利用植物物种对特定生境的保守性和植物群落的物种丰富度快速评估栖息地质量的方法.基于样方物种组成和专家赋值的植物物种保守系数,运用简单的公式即可计算出样方的植物区系质量指数(FQI).该指数能够反映植被的完整性和退化程度,可以用于对栖息地质量进行时空对比,已经在美国、加拿大等十余个国家广泛应用.本文介绍该方法的原理、计算公式和应用案例,为生态管理工作者和研究人员提供一种简单、可重复、可对比的生境质量评估工具.
The purpose of this study was to investigate the effects of dietary supplementation of compound probiotics on the performance, egg quality, biochemical parameters and intestinal morphology of laying hens. A total of 180 healthy 200-day-old Hyline Brown laying hens with similar initial laying rate (87.5% ± 0.2%) were randomly divided into the control group and the treatment group. Each group included 6 replicates and each replicate included 15 laying hens. The control group was provided a basal diet, while the treatment group received the basal diet supplemented with compound probiotics. The experiment lasted for 52 days. The study indicated the following outcomes: (1) The laying rate (LR) and average egg weight (AEW) of laying hens in the treatment group were significantly higher than those of the control group ( p < 0.05), whereas the feed-to-egg ratio (F/E) was significantly lower ( p < 0.05); (2) The yolk weight (YW), egg shape index (ESI) and albumen height (AH) were significantly higher ( p < 0.05), whereas the eggshell percentage (EP) was significantly lower ( p < 0.05) after the dietary supplementation of compound probiotics; (3) The treatment group significantly decreased in total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), immunoglobulin A (IgA), and immunoglobulin G (IgG) levels in serum compared to the CON group ( p < 0.05). Additionally, serum levels of total protein (TP), globulin (GLB), albumin (ALB), high-density lipoprotein (HDL), alkaline phosphatase (ALP), and total antioxidant capacity (T-AOC) were significantly higher in the treatment group ( p < 0.05); (4) The supplementation of compound probiotics to laying hen diets led to a significant reduction in crypt depth (CD) and the ratio of villus height to crypt depth (V/C) in the jejunum compared to the CON group ( p < 0.05). In conclusion, the supplementation of compound probiotics can regulate the body metabolism and improve the intestinal morphology, thus enhancing the antioxidant capacity and immune function of the body, which in turn improves the performance and egg quality of laying hens.
DNA barcoding is widely used in toxic species authentication, but due to serious DNA degradation of forensic materials, the application of full-length barcode sequences in food poisoning diagnosis is greatly limited. Nucleotide signature, a shorter specific molecular marker, derived from traditional DNA barcoding has been proposed as an emerging tool of toxic species detection in deeply processed materials. In this study, to resolve the frequent food poisoning accidents with unknown origin, we envisioned developing a nucleotide signature data set of common poisonous organisms and combining high-throughput sequencing (HTS) to reveal the poisoning cause. Ninety-three individuals and 1093 DNA barcode sequences of twelve common poisonous plants, fish, mushrooms and their related species were collected. Through sequence alignment and screening, the nucleotide signatures were respectively developed and validated as their specific molecular markers. The sequence length varied from 19 bp to 38 bp. These fragments were conserved within the same species or genera, and the specificity between related species has been also demonstrated. To further evaluate the application potential of nucleotide signature in forensic diagnosis, simulated forensic specimens (SFS) containing different poisonous ingredients were sequenced by HTS with PCR-free libraries. As a result, the nucleotide signature was successfully captured from original HTS data without assembly and annotation, accompanied by a high detection sensitivity of 0.1 ng/µl in mixture system. Therefore, this method was suitable for the assay of forensic materials with serious DNA degradation. The present study undoubtedly provides a new perspective and strong support for the detection of toxic ingredients and the diagnosis of food poisoning.
Rationale: PCDH19-related epilepsy manifested various clinical features, including febrile epilepsy, with or without intellectual disability, and psych-behavioral disorders. However, there are few studies demonstrating abdominal pain as the first symptom. Patient concerns: A 3-year-old Chinese girl presented with clustered seizures of fever sensitivity accompanied by abdominal pain. Diagnoses: After ultrasonography ruled out abdominal organic lesions, electroencephalographic (EEG) identified abdominal pain was a seizure feature. Trio whole-exome sequence demonstrated a de novo and heterozygous PCDH19 missense mutation (NM_001184880: c.824A>G, P.Y275C), which was confirmed by Sanger sequence. The final diagnosis were “PCDH19-related epilepsy; abdominal pain.” Interventions: At first, she was treated ineffectively by levetiracetam and valproate. Finally, she was provided with topiramate (TPM). Outcomes: The patient had gained seizure-free, and the follow-up EEG discharges were reduced. Lessons: Abdominal pain is a rare autonomic symptom in the setting of seizures. This report describes abdominal pain as a novel manifestation of PCDH19-related epilepsy and might expand its phenotypes spectrum. It also alerts us to perceive the abdominal pain characterized by seizures and early conduct EEG examination to clarify the nature of abdominal pain.
To analyze standards of alginate-based medical devices at home and abroad, and to emphasize key issues of quality control that should be concerned about.
Objective
To study the application of extrusion method in inducing liposome membrane fusion or membrane component mixing, and to investigate the effect of different extrusion conditions on liposome membrane fusion rate.
Methods
N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) phosphatidylethanolamine (N-NBD-PE) and N-(lissamine rhodamine B sulfonyl) phosphatidylethanolamine (N-Rh-PE) labeled 1, 2-dioleoyl lecithin (DOPC) liposomes and non-fluorescently labeled DOPC monolayer liposomes were mixed and extruded. The fluorescence changes before and after the extrusion of the mixed liposomes were observed using laser scanning confocal microscope, and the membrane fusion rate of the mixed liposomes was calculated by fluorescence resonance energy transfer method. Besides, the effects of extrusion times, extrusion pressure and temperature on the fusion rate of liposome membrane were studied.
Results
The results of laser scanning confocal microscopy showed that the distribution density and intensity of the green fluorescence of N-NBD-PE increased significantly after the extrusion of fluorescently labeled and non-fluorescent labeled DOPC liposomes, which confirmed membrane fusion. After 75 times of extrusion treatments, the liposome membrane fusion rate can reach 26%. The number of extrusions, extrusion pressure and temperature had a significant effect on the fusion rate of the liposome membrane. The higher the number of the extrusions, the smaller the extrusion pressure and the higher the efficiency of the liposome membrane fusion were at physiological temperature.
Conclusions
Extrusion method can induce liposome membrane fusion and membrane component mixing, and the prepared liposome has a narrower particle size distribution, which is expected to be a new method to induce the bilayer membrane fusion of liposome or lipid vesicle.
Key words:
Extrusion; Liposome; Lipid bilayer fusion; Fluorescence resonance energy transfer