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1.
Int J Biol Macromol ; 271(Pt 1): 132333, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38754686

RESUMO

The fabrication of scaffolds capable of the sustained release of the vascular endothelial growth factor (VEGF) to promote angiogenesis for a long time remains a challenge in tissue engineering. Here, we report a facile approach for effectively fabricating a bioactive scaffold that gradually releases VEGF to promote angiogenesis. The scaffold was fabricated by coating polydopamine (PDA) on a konjac glucomannan (KGM) scaffold, followed by the surface immobilization of VEGF with PDA. The resulting VEGF-PDA/KGM scaffold, with a porous and interconnected microstructure (392 µm pore size with 84.80 porosity), combined the features of long-term biodegradability (10 weeks with 51 % degradation rate), excellent biocompatibility, and sustained VEGF release for up to 21 days. The bioactive VEGF-PDA/KGM scaffold exhibited multiple angiogenic activities over time, as confirmed by in vivo and in vitro experiments. For example, the scaffold significantly promoted the attachment and proliferation of human umbilical vein endothelial cells and the formation of vascular tubes in vitro. Moreover, the in vivo results demonstrated the formation and maturation of blood vessels after subcutaneous implantation in rats for four weeks. This promising strategy is a feasible approach for producing bioactive materials that can induce angiogenesis in vivo. These findings provide a new avenue for designing and fabricating biocompatible and long-term biodegradable scaffolds for sustained VEGF release to facilitate angiogenesis.

2.
J Exp Bot ; 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38551389

RESUMO

Nutrient availability profoundly influences plant root system architecture, which critically determines crop productivity. While Arabidopsis has provided important insights into the genetic responses to nutrient deficiency, translating this knowledge to crops, particularly wheat, remains a subject of inquiry. Here, examining a diverse wheat population under varying nitrogen (N), phosphorus (P), potassium (K), and iron (Fe) levels, we uncover a spectrum of root responses, spanning from growth inhibition to stimulation, highlighting genotype-specific strategies. Furthermore, we reveal a nuanced interplay between macronutrient deficiency (N, P, and K) and Fe availability, emphasizing the central role of Fe in modulating root architecture. Through genome-wide association mapping, we identify 11 quantitative trait loci underlying root traits under varying nutrient availabilities, including homologous genes previously validated in Arabidopsis, supporting our findings. In addition, utilizing transcriptomics, ROS imaging, and antioxidant treatment, we uncover that wheat root growth inhibition by nutrient deficiency is attributed to ROS accumulation, akin to the role of ROS in governing Arabidopsis root responses to nutrient deficiency. Therefore, our study reveals the conservation of molecular and physiological mechanisms between Arabidopsis and wheat to adjust root growth to nutrient availability, paving the way for targeted crop improvement strategies aimed at increasing nutrient use efficiency.

3.
Carbohydr Polym ; 330: 121812, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38368083

RESUMO

Biomacromolecules based injectable and self-healing hydrogels possessing high mechanical properties have widespread potential in biomedical field. However, dynamic features are usually inversely proportional to toughness. It is challenging to simultaneously endow these properties to the dynamic hydrogels. Here, we fabricated an injectable nanocomposite hydrogel (CS-NPs@OSA-l-Gtn) stimultaneously possessing excellent autonomous self-healing performance and high mechanical strength by doping chitosan nanoparticles (CS-NPs) into dynamic polymer networks of oxidized sodium alginate (OSA) and gelatin (Gtn) in the presence of borax. The synergistic effect of the multiple reversible interactions combining dynamic covalent bonds (i.e., imine bond and borate ester bond) and noncovalent interactions (i.e., electrostatic interaction and hydrogen bond) provide effective energy dissipation to endure high fatigue resistance and cyclic loading. The dynamic hydrogel exhibited excellent mechanical properties like maximum 2.43 MPa compressive strength, 493.91 % fracture strain, and 89.54 kJ/m3 toughness. Moreover, the integrated hydrogel after injection and self-healing could withstand 150 successive compressive cycles. Besides, the bovine serum albumin embedded in CS-NPs could be sustainably released from the nanocomposite hydrogel for 12 days. This study proposes a novel strategy to synthesize an injectable and self-healing hydrogel combined with excellent mechanical properties for designing high-strength natural carriers with sustained protein delivery.


Assuntos
Alginatos , Quitosana , Alginatos/química , Nanogéis , Gelatina/química , Hidrogéis/química , Polímeros , Quitosana/química
4.
Leg Med (Tokyo) ; 59: 102129, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35944342

RESUMO

In this study we have provided forensic genetic data of 22 autosomal STRs for Pakhtun, Balochi and Balti population of Pakistan in total of 601 samples. Among these loci, Penta E was found the most discriminatory in all groups and allele 15 was observed most frequent at D22S1045 in Balti whereas in other two populations allele 8 was more common at TPOX. The combined power of discrimination, combined power of exclusion and the combined matching probability was calculated as 0.999999999999999999999999998385, 0.999999988089728 and 1.615 × 10-27 respectively. Based on population differentiation test, significant differences were observed when compared with other populations however, phylogenetic analysis revealed close genetic associations among Pakistani Populations.


Assuntos
Genética Populacional , Repetições de Microssatélites , Humanos , Repetições de Microssatélites/genética , Frequência do Gene/genética , Paquistão , Filogenia , Loci Gênicos
6.
Front Chem ; 8: 102, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32211372

RESUMO

Tough gel with extreme temperature tolerance is a class of soft materials having potential applications in the specific fields that require excellent integrated properties under subzero temperature. Herein, physically crosslinked Europium (Eu)-alginate/polyvinyl alcohol (PVA) organohydrogels that do not freeze at far below 0°C, while retention of high stress and stretchability is demonstrated. These organohydrogels are synthesized through displacement of water swollen in polymer networks of hydrogel to cryoprotectants (e.g., ethylene glycol, glycerol, and d-sorbitol). The organohydrogels swollen water-cryoprotectant binary systems can be recovered to their original shapes when be bent, folded and even twisted after being cooled down to a temperature as low as -20 and -45°C, due to lower vapor pressure and ice-inhibition of cryoprotectants. The physical organohydrogels exhibit the maximum stress (5.62 ± 0.41 MPa) and strain (7.63 ± 0.02), which is about 10 and 2 times of their original hydrogel, due to the synergistic effect of multiple hydrogen bonds, coordination bonds and dense polymer networks. Based on these features, such physically crosslinked organohydrogels with extreme toughness and wide temperature tolerance is a promising soft material expanding the applications of gels in more specific and harsh conditions.

7.
Pak J Med Sci ; 36(2): 255-259, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32063970

RESUMO

OBJECTIVE: To determine the quality of life of students of a private medical college in Karachi in Pakistan. METHODS: This cross sectional study was conducted among 217 medical students of Liaquat College of Medicine and Dentistry, Karachi from June 2017 to March 2018. Students were selected by a stratified sampling method and the World Health Organization Quality of Life BREF Instruments (WHO QOL-BREF) was used for the above-mentioned study. Statistical analysis was performed using SPSS (Statistical Package for Social Sciences) version 21 and Analysis of variance (ANOVA). Independent t-test was used as p <0.05 significant. RESULTS: A total of 250 questionnaires were distributed among 2nd year, 3rd year, 4th year and final year students and the response rate was 86.8%. Among them 48.5% (n=105) students were male and 51.5% (n=112) students were female, while 9.2% (n=20) students were currently ill and the other 90.8% (n=197) were healthy. CONCLUSION: Medical education influences the quality of life (QOL) of students adversely. Social relationships and environmental domain were satisfactory in private medical institutes whereas physical and psychological progress was low due to academic load which requires improvement either by physical activities such as fitness classes or other extra-curricular activities.

8.
Chemosphere ; 216: 564-575, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30390587

RESUMO

Recently, there is a growing interest among agriculturists to use nanotechnology for the development of nutrient-use efficient fertilizers. However, its sustainable use for the synthesis of mineral or organic nano-fertilizers requires a thoughtful of the mechanism as well as the fate of nutrients and their interaction with soil-plant systems. Therefore, the aim of current study was to investigate the mixing of three different application rates of zinc oxide nanoparticles (ZNPs: 1.4, 2.8 and 3.6 mg kg-1 soil) as well as zeolite (141, 282 and 423 mg kg-1 soil) with biogas slurry (AS) on soil nutrient availability and herbage nitrogen (N) and zinc (Zn) uptake in a standard pot experiment. We found that both ZNPs and zeolite significantly increased mineral N content in soil compared to AS alone (P < 0.05). On the other hand, plant available phosphorus or potassium and microbial biomass carbon (C) in the soil were neither significantly affected by any application rate of ZNPs nor zeolite mixed AS. Soil microbial biomass N was significantly higher in second and third application rates of both ZNPs and zeolite amended AS treatments compared to AS alone. However, this increment in mineral N did not influence shoot uptake and herbage apparent recovery of this nutrient from AS. Similarly, co-mixing of both ZNPs and zeolite in AS did not influence shoot N uptake but Zn uptake was significantly higher in this treatment compared to AS alone. Therefore, this combination would be considered for improving crop Zn uptake under such fertilizer management regimes.


Assuntos
Biocombustíveis , Nanopartículas/química , Nitrogênio/análise , Nutrientes/metabolismo , Solo/química , Zeolitas/química , Óxido de Zinco/química , Biomassa , Fertilizantes/análise , Nutrientes/análise
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