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1.
Appl Opt ; 60(29): 9160-9166, 2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34623998

RESUMO

Terahertz (THz) metamaterial absorbers have realized a prodigious reputation due to the limitation of natural absorbing materials in this range. Getting wideband absorption characteristics is challenging and arduous, especially in the THz band. Self-similar repeated fractal elements offer a promising solution to attain broadband absorption response due to their inherent multiple resonance characteristics. Therefore, by captivating the advantage of fractal geometry, we proposed a dual and wideband meta-absorber operating in the THz regime. The metamaterial absorber design comprises the assembly of self-similar square-shaped blocks arranged in a specific pattern to construct the fractal geometry. The proposed THz absorber demonstrates 90% absorption under normal incident waves for two operating bands from 9.5-10.55 THz and 12.3-13.35 THz. The suggested metamaterial absorber also shows good and stable absorption responses under different oblique incidence angles for transverse electric (TE) and transverse magnetic (TM) wave polarization. Moreover, this absorber manifests over 85% absorptivity in its entire operating range (9-14 THz) under the incidence angle of 60° and 70° for TM mode. Furthermore, it gives a polarization-insensitive behavior under the effect of different polarization angles. This kind of wideband absorber catches fascinating applications in THz detection, imaging, cloaking, and optoelectronic devices.

2.
J Therm Biol ; 99: 102944, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34420608

RESUMO

Environmental changes pose significant threats to agricultural activities particularly animal production. These changes have induced major concerns which will negatively affect the poultry health and productivity under the current climate changes. Moreover, they also alter the immunological status of the exposed birds and make them susceptible to different diseases. The adverse effects of environmental stress also include poor performance of birds (reduced feed intake, growth, feed efficiency, immunity, and egg production) and inferior product quality. The adverse effect of heat stress on different quail breeds like Japanese quail, bobwhite quail, scaled quail, and Gambel's quail ranged from decreased growth rates (11.0-14.5%), body weight (7.7-13.2%), feed intake (6.1-21.6%), feed efficiency (4.3-8.6%), and egg production (6.6-23.3%). Also, birds reared under heat stress (34 °C) had significantly decreased Haugh units by 10.8% and egg weight by 14.3% in comparison with the control group (reared at 22 °C). On the other hand, increasing stoking density from 30 to 45 kg/m2 also negatively affected the feed intake and body weight. Recent studies have focused on evaluating the potential adverse effects of different environmental stresses on poultry performance, behavior, welfare, and reproduction. It is imperative to understand better the interaction of different environmental factors and their subsequent effects on avian physiology, to spotlights on the effective management and nutritional strategies to alleviate the adverse effects of different stresses in poultry. This review aims to present a comprehensive overview of physiological manifestations of major environmental stresses including thermal stress (heat and cold stress) and high stocking densities on poultry health and production. Moreover, we have also critically evaluated the scope and efficacy of some potential strategies to mitigate the influences of these environmental stressors in different poultry species.

3.
Toxicology ; 461: 152906, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34450209

RESUMO

Fluoride is one of the most widely distributed elements in nature, while some fluorine-containing compounds are toxic to several vertebrates at certain levels. The current study was performed to evaluate the nephrotoxic effects of fluoride exposure in ducks. The results showed that the renal index was decreased in NaF group, and fluoride exposure significantly decreased the levels of serum Albumin, Glucose, Total cholesterol, Urea, protein and Triglycerides, confirming that NaF exhibited adverse effects on the kidney. The overall structure of renal cells showed damage with the signs of nuclelytic, vacuolar degeneration, atrophy, renal cystic cavity widening after fluoride induction. Renal vascular growth was impaired as the expression of VEGF and HIF-1α decreased (p > 0.05). More importantly, autophagy and apoptosis levels of CYT C, LC3, p62, Beclin, M-TOR, Bax and Caspase-3 were increased (p < 0.05) in the NaF treated group. Interestingly, our results showed that Phosphatidylethanolamine (PE) and Phosphatidylcholine (PC) activated the M-TOR autophagy pathway. Meanwhile, the PE acted on Atg5/ LC3 autophagy factor, followed by the auto-phagosome generation and activation of cell autophagy. These results indicate that NaF exposure to duck induced nephron-toxicity by activating autophagy, apoptosis and glucolipid metabolism pathways, which suggest that fluorine exposure poses a risk of poisoning.

4.
Anim Biotechnol ; : 1-10, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34191667

RESUMO

Antibiotic resistance is looming problem in broiler production globally and there has been an increasing interest to look for sustainable alternatives to antibiotics. Yeast and its derived products are recognized as potential feed additives because of their beneficial impacts on poultry. Particularly, yeast exhibited positive effects on the humoral immunity by increasing serum immunoglobulin (Ig) A levels. Moreover, yeast and its products showed immune adjuvant-like properties that helped the broilers chicken to develop faster and stronger innate immune response under pathogenic challenges. Use of yeast and its products as prebiotic/probiotic improves the gut architecture mainly by improving the gut development and gut microbiome, reduction in colonization of pathogens through competitive exclusion, binding of toxins and enhancing digestion and absorption of nutrients. These unique properties of yeast and yeast products enhance animal welfare and productivity; warrant them to be used as a promising feed additive. This article, therefore, provides insights into the functional role of yeast and its products in the broiler diets and highlights its importance as a commercially viable alternative of synthetic antibiotic growth promoters in the broiler feed industry.

5.
Ecotoxicol Environ Saf ; 212: 111968, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33550083

RESUMO

Despite the fact that copper (Cu) is a vital micronutrient to maintain body function, high doses of Cu through environmental exposure damage various organs, especially the liver, which is the main metabolic organ. To investigate the influence of long-term Cu-induced toxicity on mitophagy and apoptosis in rat liver, 96 seven-month-old male Sprague-Dawley rats were fed TBCC for 24 weeks. The results revealed that exposure to high Cu concentrations could promote oxidative stress liver injury by increasing the hepatic function index (ALT, AST and ALP) and MDA content, while reducing the activity of antioxidant enzymes (T-SOD, GSH-Px and CAT) related to oxidative stress. Consistent with histopathological observations, proper dietary Cu (15-60 mg/kg) could improve antioxidant stress levels and induce a dose-dependent increase in the mRNA expression of mitophagy-related genes, whereas a high Cu concentration (120 mg/kg) could cause severe liver impairment and ultrastructural changes and a reduction in mitophagosomes, accompanied by downregulation of Atg5, Beclin1, Pink1, Parkin, NIX, P62 and LC3B. The expression of apoptosis-related genes (Bax, Bax/Bcl-2, Caspase3, Cytc and p53) and proteins (Caspase3 and p53) was upregulated with the addition of dietary Cu. The results demonstrated that an appropriate dose of TBCC could improve liver function by promoting mitophagy and Cu enzymes that play antioxidative roles, while the accumulation of excess Cu could induce liver lesions by enhancing apoptosis and inhibiting mitophagy pathways.


Assuntos
Cloretos/toxicidade , Cobre/toxicidade , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Sulfato de Cobre/análise , Dieta , Fígado/metabolismo , Masculino , Mitofagia/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Testes de Toxicidade Crônica
6.
Anim Biotechnol ; : 1-14, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33325302

RESUMO

The effects of inclusion of powdered seeds of black cumin (B) (Nigella sativa L.) and fenugreek (F) (Trigonella foenum-graecum L.) on productive traits, selected blood constituents, microbiota and immunity of broilers were studied. A total of 648 day-old chicks were randomly assigned to nine treatments, with four pen replicates, each with 18 birds, including three levels of B seed powder (BSP; 0, 5 or 10 g/kg) and three levels of F seed powder (FSP; 0, 5 or 10 g/kg) in a 3 × 3 factorial arrangement. Neither powder affected feed intake. The FSP increased (p = 0.048) feed conversion ratio (FCR), but decreased daily BW gain (p = 0.02) between days 0 and 21, while BSP increased daily gain between days 22 and 42 and overall (both p = 0.005). Abdominal fat was decreased (p = 0.003) by BSP. Blood constituents were unaffected by either powder, but ileal Escherichia coli were decreased (p = 0.039) at day 42. The BSP increased a range of immunological titers, where BSP affected positively the measured variables. The interactions between BSP and FSP, specifically on broiler carcass cuts, suggested that where BSP is included at 10 g/kg, the inclusion of FSP at the same level may provide no additional benefit. Thus, while either powder could be included separately, the co-inclusion of both at 10 g/kg is not recommended.

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