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801.
Fusarithioamide B (6), a new aminobenzamide derivative with unprecedented carbon skeleton and five known metabolites: stigmast-4-ene-3-one (1), stigmasta-4,6,8(14),22-tetraen-3-one (2), p-hydroxyacetophenone (3), tyrosol (4), and fusarithioamide A (5) were separated from Fusarium chlamydosporium EtOAc extract isolated from Anvillea garcinii (Burm.f.) DC. leaves (Asteraceae). The structure elucidation and complete assignment of the isolated metabolites were performed mainly by the aid of various NMR and MS data. Fusarithioamide B (6) has been assessed for antibacterial and antifungal activities towards various microbial strains by disc diffusion assay. It exhibited selective antifungal activity towards C. albicans (MIC 1.9?µg/ml and IZD 14.5?mm), comparing to clotrimazole (MIC 2.8?µg/ml and IZD 17.9?mm). Also, it possessed high antibacterial potential towards E. coli, B. cereus, and S. aureus compared to ciprofloxacin. Furthermore, 6 was tested for the in vitro cytotoxic effect against KB, HCT-116, BT-549, MCF-7, SKOV-3, and SK-MEL cell lines. It had selective and potent effect towards BT-549, MCF-7, SKOV-3, and HCT-116 cell lines with IC50s 0.09, 0.21, 1.23, and 0.59?μM, respectively compared to doxorubicin (IC50s 0.046, 0.05, 0.321, and 0.24?μM, respectively). Fusarithioamide B may provide a lead molecule for future developing of antitumor and antimicrobial agents.  相似文献   
802.
This study provides an integrated approach using geographical information system (GIS) based on a multi-criteria approach (MCDA) to assess coastal vulnerability, resulting from human activity, population density, erosion, and climate change-induced sea level rise. A coastal vulnerability index (CVI) for erosion and floods was calculated and mapped (~24 km in length; ~400 m in width, and 11.47 km2 in surface) for the lagoon barrier of Nador located on the Mediterranean coast of Morocco. Results suggest that 54% (~13 km) of the shoreline is moderately vulnerable, while 42% (~10 km) is highly vulnerable and only 4% (1 km) present a low vulnerability. The vulnerability map of the socio-economic activities indicates that most wetlands and forest areas 83% (~31 ha) and 50% (~440 ha) respectively, present low vulnerability. 52% percent of artificial areas (~23 ha), 73% of agricultural land (~128 ha), and 41% of natural areas (~363 ha) present moderate vulnerability. However, the level of vulnerability of the remaining artificial and agricultural areas classifies from high to very high. The north-western sector was classified as the most vulnerable area, characterized by an erosion (?0.6 m/yr to ?1.20 m/yr) for 70% of this area, while the south-eastern part shows a low to moderate vulnerability marked by an erosion (?0.1 m/yr to ?1m/yr) for 40% of this area. Coastal vulnerability maps have potential as decision tools to prepare and respond to sea level rise, and identify exposed coastal zones, as such contributing to national climate action and disaster risk reduction sustainable development goals (goals 13 and 11, respectively).  相似文献   
803.
The Oualidia lagoon provides important ecosystem services, such as fishing, aquaculture, tourism and high biological and ecological productivity. Many indices have been developed to evaluate environmental risks and to estimate the anthropogenic contribution of potentially toxic elements (PTE) in surficial sediments. The results show that the concentrations of the PTE found in surface sediments due to the anthropogenic activities in the area (urban effluents, aquaculture and agricultural areas) are significantly higher than those from the local background and sediment quality guidelines (SQGs). The potential ecological and biological risk index present satisfactory results. However, the sites near to the areas where anthropogenic activities are developed present 49% probability of toxicity, while the rest of the lagoon, present 9% to 21% probability of toxicity and low potential ecological risk, except for Hg where the risk was considered to be considerable. The PTE are mainly originated from the anthropogenic activities; nevertheless, anthropogenic contributions represent up to 69% of the total sediment of content, but it depends on the PTE: Cd (16%), Ni (38%), Zn (41%), Cr (43%), Cu (56%), Hg (68%), Pb (69%). Compared with the Sub-basin soils, the PTE are higher than 80%, hence the sub-basin feeds the lagoon by these elements (PTE).  相似文献   
804.
Little is known of the occurrence and age patterns of species/genotypes and subtypes of Cryptosporidium spp. and Giardia duodenalis in calves in Egypt. In this study, 248 fecal specimens were collected from dairy calves aged 1?day to 6?months on eight farms in three provinces during March 2015 to April 2016. Cryptosporidium spp. were detected and genotyped by using PCR-RFLP analysis of the small subunit rRNA (SSU rRNA) gene, while G. duodenalis was detected and genotyped by using PCR and sequence analyses of the triose phosphate isomerase (tpi), glutamate dehydrogenase (gdh) and β-giardin (bg) genes. The overall infection rates of Cryptosporidium spp. and G. duodenalis were 9.7 and 13.3%, respectively. The highest Cryptosporidium infection rate (26.7%) was in calves of age?≤?1?month while the highest G. duodenalis infection rate (44.4%) was in calves of 2?months. Three Cryptosporidium spp. were identified, including C. parvum (n?=?16), C. bovis (n?=?5) and C. ryanae (n?=?3), with the former being almost exclusively found in calves of ≤3?months of age and the latter two being only found in calves of over 3?months. Subtyping of C. parvum by PCR-sequence analysis of the 60?kDa glycoprotein gene identified subtypes IIaA15G1R1 (n?=?15) and IIaA15G2R1 (n?=?1). The G. duodenalis identified included both assemblages E (n?=?32) and A (n?=?1), with the latter belonging to the anthroponotic subtype A2. These data provide new insights into the genetic diversity and age patterns of Cryptosporidium spp. and G. duodenalis in calves in Egypt.  相似文献   
805.
Pteropus livingstonii and Pteropus seychellensis comorensis are endemic fruit bat species that are among the most threatened animals in the Comoros archipelago. Both species are pollinators and seed dispersers of native and cultivated plants and are thus of crucial importance for the regeneration of natural forests as well as for cultivated plantations. However, these species are subject to strong anthropogenic pressures and face one of the highest rates of natural habitat loss reported worldwide. Yet little is known about the population genetic structure of these two species, making it difficult to define relevant conservation strategies. In this study, we investigated for the two flying fox species (1) the level of genetic diversity within islands, as well as across the archipelago and (2) the genetic structure between the two islands (Anjouan and Mohéli) for P. livingstonii and between the four islands of the archipelago (Anjouan, Mohéli, Grande Comore and Mayotte) for P. s. comorensis using mitochondrial and microsatellite markers. The results revealed contrasting patterns of genetic structure, with P. s. comorensis showing low genetic structure between islands, whereas P. livingstonii exhibited high levels of inter-island genetic differentiation. Overall, the genetic analyses showed low genetic diversity for both species. These contrasting genetic patterns may be the result of different dispersal patterns and the populations’ evolutionary histories. Our findings lead us to suggest that in terms of conservation strategy, the two populations of P. livingstonii (on Anjouan and Mohéli islands) should be considered as two separate management units. We recommend focusing conservation efforts on the Anjouan population, which is the largest, exhibits the highest genetic diversity, and suffers the greatest anthropogenic pressure. As for P. s. comorensis, its four populations could be considered as a single unit for conservation management purposes. For this species, we recommend protecting roosting trees to reduce population disturbance.  相似文献   
806.
Developing effective stem cell-based therapies requires the design of complex in vitro culture systems for accurate representation of the physiological stem cell niche. Human amniotic membrane (hAM) has been successfully used in clinical grafting applications due to its unique biological and regenerative properties. Decellularized hAM (d-hAM) has been previously applied to the culture of human bone marrow mesenchymal stem cells (hMSCs), promoting their expansion and differentiation into adipogenic and osteogenic lineages. In the present study, hAM was decellularized by NaOH-treatment, to provide the three-dimensional (3D) bioscaffold for culturing hMSCs. The ultrastructural differences between intact hAM and decellularized hAM were characterized using the transmission electron microscope (TEM), as well as the 3D interaction between d-hAM and hMSCs cultured on the membrane. TEM examination of the intact hAM showed many microvilli on the epithelial layer cells, active Golgi apparatus, smooth endolplasmic reticulum and the characteristic pinocytic vesicles. The epithelial layer with its structures was absent in the d-hAM. However, no observable difference was detected in the ultrastructural characteristics of the compact stromal layer of d-hAM compared to intact hAM. Both contained bundles of extra cellular matrix (ECM) proteins, and scattered elastic fibres. Cultured human mesenchymal stem cells (hMSCs) examined by TEM appeared oval to spherical in shape and had a rough and non-uniform surface with distinct protrusions or irregular fillopodia. Their diameter ranged from 20.49 to 21.6 µm. Most of the cellular organelles were also noticed. SEM examination of the prepared samples revealed unique 3D interaction between the hMSC and d-hAM, where the latter seems to envelop the segments of the hMSCs lying on the surrounding membrane. This study shows that the decellularization process affected the epithelial layer only of hAM and had no effect on altering the presence of ECM components present in the stromal layer of the d-hAM. The interaction between hMSCs and d-hAM maybe mediated by hAM components other than human amniotic epithelial cells, such as ECM components or MSCs present in the deeper spongy layer of the membrane or/and the adhesive components of the basement membrane of the removed epithelial layer.  相似文献   
807.
The interest of the scientific community in biological soil crusts has grown exponentially over the last decades. One of the scientific research interests is the study of the effect of these crusts on plant establishment. Findings in this topic have been controversial, and some differences were attributed to crust types. Biological soil crusts dominated by lichens are common components of Stipa tenacissima steppes in arid and semi‐arid environments of the southern Mediterranean. In the current study, we conducted growth chamber experiments to investigate the differential effects of two lichen species with continuous crustose thalli (Diploschistes diacapsis) and with squamulose semicontinuous thalli (Fulgensia bracteata) on seed germination, root penetration, shoot emergence and seed viability of the tussock grass species S. tenacissima. Our results showed that under laboratory conditions, two distinct lichen species had significantly different effects on the establishment of S. tenacissima. Our findings clearly demonstrated that D. diacapsis significantly decreased germination, root penetration and shoot emergence of S. tenacissima compared to F. bracteata. This can be related to differences in morphological and physiological characteristics between crustose and squamulose lichens. Overall, we suggest that D. diacapsis and crustose lichens generally can act as natural barrier to the establishment of S. tenacissima.  相似文献   
808.
Niosomes have been claimed to enhance intestinal absorption and to widen the absorption window of acidic drugs. This was reported after monitoring the intestinal absorption in situ. Accordingly, the aim of this work was to investigate the effect of niosomal encapsulation on intestinal absorption and oral bioavailability of nateglinide. This was conducted with the goal of correlation between in situ intestinal absorption and in vivo availability. The drug was encapsulated into proniosomes. The niosomes resulting after hydration of proniosomes were characterized with respect to vesicle size and drug entrapment efficiency. The in situ rabbit intestinal absorption of nateglinide was monitored from its aqueous solution and niosomes. Streptozotocin was used to induce diabetes in albino rats which were then used to assess the hypoglycemic effect of nateglinide after oral administration of aqueous dispersion and niosomal systems. The prepared vesicles were in the nanoscale with the recorded size being 283?nm. The entrapment efficiency depended on the pH of the formulation. The in situ intestinal absorption reflected non-significant alteration in the membrane transport parameters of the drug after niosomal encapsulation compared with the free drug solution. In contrast, niosomes showed significant improvement in the rate and extent of the hypoglycemic effect compared with the unprocessed drug. This discrepancy can be attributed to different transport pathway for the drug after niosomal inclusion with the vesicles undergoing translymphatic transport which can minimize presystemic metabolism. However, this requires confirmatory investigations. In conclusion niosomes can enhance oral bioavailability of nateglinide with the absorption being through nontraditional pathway.  相似文献   
809.
Based on the importance of producing in vitro adventitious roots, this study was carried out to investigate the effects of indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) at a concentration of 2 mg L?1 on the formation of adventitious roots of azalea and their impact on biochemical changes and endogenous hormones. The rooting percentage, root number, and root length were increased in the microshoots of both studied cultivars (‘Mingchao’ and ‘Zihudie’) when the growth medium was supplemented with IBA. Additionally, peroxidase, indole acetic acid oxidase, hydrogen peroxide, and soluble protein contents were improved in both cultivars by auxin treatments especially during the first 7 days of the rooting period. However, application of IBA and NAA increased catalase and polyphenol oxidase in both cultivars during the first 14 and 28 days of culture. The increase in endogenous indole acetic acid (IAA) levels was accompanied by low activity of IAAO during most periods of root induction of microshoots in all treatments. Endogenous gibberellic acid levels were increased after 7 days of culture and then increased again after 28 days of culture. In contrast, the levels of endogenous zeatin riboside and isopentenyl adenosine were decreased with auxin treatments in the first period of the rooting process and then increased after 21 and 28 days of culture. The present study demonstrated that IBA at a concentration of 2 mg L?1 has a strong effect on azalea rooting. Moreover, the efficiency of IBA and NAA effects on biochemical changes during adventitious root induction was investigated, which may provide new horizons of in vitro rooting production and provide valuable information for the micropropagation of Rhododendron plants.  相似文献   
810.
The two-spotted spider mite, Tetranychus urticae Koch, is an important pest of cotton in mid-southern USA and causes yield reduction and deprivation in fiber fitness. Cotton and pinto beans grown in the greenhouse were infested with spider mites at the three-leaf and trifoliate stages, respectively. Spider mite damage on cotton and bean canopies expressed as normalized difference vegetation index indicative of changes in plant health was measured for 27 consecutive days. Plant health decreased incrementally for cotton until day 21 when complete destruction occurred. Thereafter, regrowth reversed decline in plant health. On spider mite treated beans, plant vigor plateaued until day 11 when plant health declined incrementally. Results indicate that pinto beans were better suited as a host plant than cotton for rearing T. urticae in the laboratory.  相似文献   
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