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排序方式: 共有237条查询结果,搜索用时 265 毫秒
181.
Valerio Zupo Francesca Glaviano Marina Paolucci Nadia Ruocco Gianluca Polese Anna Di Cosmo Maria Costantini Mirko Mutalipassi 《Aquaculture Nutrition》2019,25(1):26-38
Sea urchin gonads are exploited both for gastronomic and scientific purposes; thus, the production of large and mature gonads is essential. Natural populations of the Mediterranean Sea urchin Paracentrotus lividus are subject to increasing fishing efforts, due to continuous intensification of consumptions. Aquaculture practices may represent an answer, but the availability of artificial feeds accelerating the production of high‐quality gonads in terms of size, taste, colour, firmness, maturity and viability of gametes is critical to boost the productions. The accessibility of cheap and effective feeds promoting the fattening of gonads and the quality of gametes is still a bottleneck slowing down the expansion of echinoculture practices. This investigation is aimed at enabling the development of this strategic sector, by comparing the dietetic effects of fresh foods and a commercial feed for aquaculture, to four newly formulated feeds. The protein contents of diets were strongly related to the GSIs. The abundance of fatty acids appeared inversely related to the viability of embryos and abnormalities of larvae. The features of an ideal diet for this sea urchin were defined, based on the results of experimental trials, and the need for increasing levels of plant‐derived proteins during the grow‐out period was demonstrated. 相似文献
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Ishtiaq Ahmed Muhammad Asgher Farooq Sher Syed Makhdoom Hussain Nadia Nazish Navneet Joshi Ashutosh Sharma Roberto Parra-Saldívar Muhammad Bilal Hafiz M. N. Iqbal 《Marine drugs》2022,20(3)
This review highlights the underexplored potential and promises of marine bioactive peptides (MBPs) with unique structural, physicochemical, and biological activities to fight against the current and future human pathologies. A particular focus is given to the marine environment as a significant source to obtain or extract high-value MBPs from touched/untouched sources. For instance, marine microorganisms, including microalgae, bacteria, fungi, and marine polysaccharides, are considered prolific sources of amino acids at large, and peptides/polypeptides in particular, with fundamental structural sequence and functional entities of a carboxyl group, amine, hydrogen, and a variety of R groups. Thus, MBPs with tunable features, both structural and functional entities, along with bioactive traits of clinical and therapeutic value, are of ultimate interest to reinforce biomedical settings in the 21st century. On the other front, as the largest biome globally, the marine biome is the so-called “epitome of untouched or underexploited natural resources” and a considerable source with significant potentialities. Therefore, considering their biological and biomedical importance, researchers around the globe are redirecting and/or regaining their interests in valorizing the marine biome-based MBPs. This review focuses on the widespread bioactivities of MBPs, FDA-approved MBPs in the market, sustainable development goals (SDGs), and legislation to valorize marine biome to underlying the impact role of bioactive elements with the related pathways. Finally, a detailed overview of current challenges, conclusions, and future perspectives is also given to satisfy the stimulating demands of the pharmaceutical sector of the modern world. 相似文献
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186.
Meli ML Kaufmann C Zanolari P Robert N Willi B Lutz H Hofmann-Lehmann R 《Veterinary microbiology》2010,146(3-4):290-294
Two alpacas from a herd in southwest Switzerland died for unknown reasons. Necropsy revealed chronic weight loss and pale mucous membranes. Infection with hemotropic mycoplasmas was suspected and subsequently confirmed by molecular methods. In order to investigate the epidemiological situation in this herd, a real-time TaqMan(?) qPCR assay for the specific detection and quantification of hemoplasma infection in South American camelids was developed. This assay was based on the 16S rRNA gene and amplified 'Candidatus Mycoplasma haemolamae' DNA, but not DNA from other hemoplasmas or non-hemotropic mycoplasma species. The lower detection limit was one copy/PCR, and the amplification efficiency was 97.4%. In 11 out of 24 clinically healthy herd mates of the two infected alpacas, 'Candidatus M. haemolamae' infection was confirmed. No correlation was found between bacterial load and clinical signs or anemia. The assay described herein enables to detect and quantify 'Candidatus M. haemolamae' and may be used in future studies to investigate the prevalence, pathogenesis and treatment follow-up of hemoplasma infections in South American camelids. 相似文献
187.
Thomas Goodrich Nadia Nawaz Stefanie Feih Brian Y. Lattimer Adrian P. Mouritz 《Journal of Wood Science》2010,56(6):437-443
This article presents an experimental study into thermal softening and thermal recovery of the compression strength properties
of structural balsa wood (Ochroma pyramidale). Balsa is a core material used in sandwich composite structures for applications where fire is an ever-present risk, such
as ships and buildings. This article investigates the thermal softening response of balsa with increasing temperature, and
the thermal recovery behavior when softened balsa is cooled following heating. Exposure to elevated temperatures was limited
to a short time (15 min), representative of a fire or postfire scenario. The compression strength of balsa decreased progressively
with increasing temperature from 20° to 250°C. The degradation rates in the strength properties over this temperature range
were similar in the axial and radial directions of the balsa grains. Thermogravimetric analysis revealed only small mass losses
(<2%) in this temperature range. Environmental scanning electron microscopy showed minor physical changes to the wood grain
structure from 190° to 250°C, with holes beginning to form in the cell wall at 250°C. The reduction in compression properties
is attributed mostly to thermal viscous softening of the hemicellulose and lignin in the cell walls. Post-heating tests revealed
that thermal softening up to 250°C is fully reversible when balsa is cooled to room temperature. When balsa is heated to 250°C
or higher, the post-heating strength properties are reduced significantly by decomposition processes of all wood constituents,
which irreversibly degrade the wood microstructure. This study revealed that the balsa core in sandwich composite structures
must remain below 200°–250°C when exposed to fire to avoid permanent heat damage. 相似文献
188.
van den Brand R Heutschi J Barraud Q DiGiovanna J Bartholdi K Huerlimann M Friedli L Vollenweider I Moraud EM Duis S Dominici N Micera S Musienko P Courtine G 《Science (New York, N.Y.)》2012,336(6085):1182-1185
Half of human spinal cord injuries lead to chronic paralysis. Here, we introduce an electrochemical neuroprosthesis and a robotic postural interface designed to encourage supraspinally mediated movements in rats with paralyzing lesions. Despite the interruption of direct supraspinal pathways, the cortex regained the capacity to transform contextual information into task-specific commands to execute refined locomotion. This recovery relied on the extensive remodeling of cortical projections, including the formation of brainstem and intraspinal relays that restored qualitative control over electrochemically enabled lumbosacral circuitries. Automated treadmill-restricted training, which did not engage cortical neurons, failed to promote translesional plasticity and recovery. By encouraging active participation under functional states, our training paradigm triggered a cortex-dependent recovery that may improve function after similar injuries in humans. 相似文献
189.
Maged El-Ashker Sabry El-Khodery Nadia Metwally Hussein Hussein Mohamed El-Boshy 《Journal of Equine Veterinary Science》2012
The present study was carried out to assess the prognostic significance of oxidative stress markers in draft horses with colitis associated with phenylbutazone administration under field condition. For this purpose, a total of 40 native breed draft horses were studied. Based on case history, physical examination, and postmortem findings, diagnosis was made. According to the clinical outcome, horses were categorized into survivors and nonsurvivors. Clinically, there was significant association between nonsurvivors and anorexia (P < .01), stasis of intestinal motility (P < .01), melena (P < .01), and diarrhea (P < .001). Biochemically, malondialdehyde and nitric oxide showed a significant increase (P < .05) in nonsurvivors compared with survivors, whereas activities of superoxide dismutase showed a significant decrease (P < .05). Analysis of receiver operating characteristic curve indicated a high sensitivity and specificity of malondialdehyde, nitric oxide, and superoxide dismutase levels (P < .001) to predict the clinical outcome of colitis. Additionally, total protein and albumin showed a significant decrease in nonsurvivors compared with survivors; however, aspartate aminotransferase, sorbitol dehydrogenase, urea, and creatinine showed an increase (P < .05). The present results suggest that estimation of oxidative stress markers and antioxidant parameters may be useful predictors of the clinical outcomes of colitis associated with phenylbutazone administration in draft horses. 相似文献
190.
The efficacy of intraosseous catheterization has not been described previously in the desert tortoise (Gopherus agassizii). The goal of this study was to describe and compare the efficacy of four intraosseous catheter sites (humerus, femur, plastocarapacial junction [bridge], and gular region of the plastron) to jugular catheterization. Five adult tortoises were catheterized in each of the sites at least once. The distribution of a bolus injection of radiopharmaceutical (technetium-99m-diethylenetriaminepentaacidic acid [99mTc -DTPA]) was monitored via gamma camera over 2-min periods at five time intervals over 24 min. Compared to jugular catheterization, the humerus and femur sites provided the next best vascular access, with 84.4 and 61.8% of activity reaching the systemic circulation by 7 min, respectively. The bridge and gular catheter sites were less effective with only 41.9 and 40.8% systemic activity, respectively. Intraosseous catheters were no more technically difficult to place than jugular catheters and were less commonly dislodged, making them a viable option for vascular access in tortoises. 相似文献