Wyniki wyszukiwania - Biblioteka Nauki

1

Application of quality control charts for early detection of flood hazards

100%

Mehmood R. , Lee M. H. , Baqar M. , Riaz M.

Polish Journal of Environmental Studies

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2020

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tom 29

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nr 6

2

Predicting the potential impacts of trophy hunting on population structure of Himalayan ibex (Capra sibirica) in Northern Pakistan

75%

Khan M. Z. , Begum F. , Riaz M. , Khan B. , Karim R. , Karamat A. , Safina A.

Polish Journal of Ecology

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2019

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tom 67

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nr 3

3

Interaction of boron and aluminum on the physiological characteristics of rape (Brassica napus L.) seedlings

75%

Yan L. , Riaz M. , Wu X. , Wang Y. , Du C. , Jiang C.

Acta Physiologiae Plantarum

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2018

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tom 40

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nr 02

EN

It has been reported that aluminum (Al) toxicity is a major limiting factor for plant growth and production on acidic soils. Boron (B) is indispensable micronutrient for normal growth of higher plants, and its addition could alleviate Al toxicity. The rape seedlings were grown under three B (0.25, 25 and 500 μM) and two Al concentrations [0 (−Al) and 100 μM (+Al) as AlCl₃·6H₂O]. The results indicated that Al stress severely hampered root elongation and root activity at 0.25 μM B while the normal (25 μM) and excess (500 μM) B improved the biomass of rape seedlings under Al exposure. Additionally, normal and excess B treatment reduced accumulation of Al in the roots and leaves under Al toxicity, which was also confirmed by hematoxylin with light staining. This indicates that both normal and excess B could alleviate Al toxicity. Furthermore, it also decreased the contents of malondialdehyde and soluble protein under Al toxicity. Likewise, superoxide dismutase activity (SOD) improved by 97.82 and 131.96% in the roots, and 168 and 119.88% in the leaves at 25 and 500 µM B, respectively, while the peroxidase and catalase activities dropped as a result of Al stress. The study results demonstrated that appropriate B application is necessary to avoid the harmful consequences of Al toxicity in rape seedlings.

4

In vitro evaluation of bioactivity of SiO2-CaO-P2O5-Na2O-CaF2-ZnO glass-ceramics

75%

Riaz M. , Zia R. , Saleemi F. , Bashir F. , Hossain T. , Kayani Z.

Materials Science Poland

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2014

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tom Vol. 32, No. 3

364--374

EN

Zinc is an essential trace element that stimulates bone formation but it is also known as an inhibitor of apatite crystal growth. In this work addition of ZnO to SiO2–CaO–P2O5–Na2O–CaF2 glass-ceramic system was made by conventional meltquenching technique. DSC curves showed that the addition of ZnO moved the endothermic and exothermic peaks to lower temperatures. X-ray diffraction analysis did not reveal any additional phase caused by ZnO addition and showed the presence of wollastonite and hydroxyapatite crystalline phases only in all the glass-ceramic samples. As bio-implant apatite forming ability is an essential condition, the surface reactivity of the prepared glass-ceramic specimens was studied in vitro in Kokubo’s simulated body fluid (SBF) [1] with ion concentration nearly equal to human blood plasma for 30 days at 37 °C under static condition. Atomic absorption spectroscopy (AAS) was used to study the changes in element concentrations in soaking solutions and XRD, FT-IR and SEM were used to elucidate surface properties of prepared glass-ceramics, which confirmed the formation of HCAp on the surface of all glass-ceramics. It was found that the addition of ZnO had a positive effect on bioactivity of glassceramics and made it a potential candidate for restoration of damaged bones.

5

Influence of Ta2O5 doping on mechanical and biological properties of silicate glass-ceramics

75%

Riaz M. , Zia R. , Saleemi F. , Bashir F. , Ahmad R. , Hossain T.

Materials Science Poland

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2016

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tom Vol. 34, No. 1

13--18

EN

The mechanical properties of silicate glass-ceramics were evaluated based on the compressive strength tests. It was found that addition improved densification, refinement of the microstructure and toughening of the bodies. The maximum compressive strength of the bodies with 1 mol% Ta2O5 was increased 3-fold (245.92 ±0.3 MPa) in comparison to undoped glass-ceramics which was measured to be 89.04 ±0.3 MPa, while for 3 mol% it became 4-fold (387.12 ±0.4 MPa) greater. The addition of Ta2O5 stabilized the system by controlling the biodegradation of the glass-ceramics. It effectively depressed the apatite formation as by addition of 3 mol% Ta2O5 no apatite layer was observed. It may be concluded from this study that mechanical and physical properties can be improved by the addition of Ta2O5 , but at a cost of bioactivity. Still the optimized composition having Ta2O5 ≤ 1 mol% may provide appropriate strength of biomaterials for high load bearing applications.

6

Seasonal variation of aflatoxin B1 content in dairy feed

63%

Ismail A. , Riaz M. , Akhtar S. , Yoo S. H. , Park S. , Abid M. , Aziz M. , Ahmad Z.

Journal of Animal and Feed Sciences

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2017

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tom 26

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nr 1

EN

Aflatoxin B1 (AFB1 ) is a fungal metabolite and highly carcinogenic compound of category 1 according to the International Agency for Research on Cancer. In the liver AFB1 from contaminated feed is bioconverted into aflatoxin M1 and can be easily diffused to the animal milk. Provision of healthy milk for humans, particularly infants and adults, therefore, entails monitoring of AFB1 level in the feed for dairy animals. In the present study, AFB1 level was monitored in three different types of animal feed comprising commercially available animal feed, fresh fodder and leftover bread fed to dairy animals between October 2014 and September 2015. AFB1 was found in all collected feed samples at the amounts: 30.5%, 2.8% and 88.9% in commercial feed, fresh fodder and leftover bread samples, respectively. All these levels were over the EU permissible limits (5 μg · kg−1). Mean maximum levels of AFB1 were observed in all samples collected in the winter season, whereas the mean minimum levels – in the summer months. The results of the present study indicated that the leftover bread samples and commercial feed contain high levels of AFB1 , and so strict measures should be adopted to prevent dairy animal feed and at the same time the animal milk from aflatoxin contamination.