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Earth harbours an extraordinary plant phenotypic diversity1 that is at risk from ongoing global changes2,3. However, it remains unknown how increasing aridity and livestock grazing pressure-two major drivers of global change4-6-shape the trait covariation that underlies plant phenotypic diversity1,7. Here we assessed how covariation among 20 chemical and morphological traits responds to aridity and grazing pressure within global drylands. Our analysis involved 133,769 trait measurements spanning 1,347 observations of 301 perennial plant species surveyed across 326 plots from 6 continents. Crossing an aridity threshold of approximately 0.7 (close to the transition between semi-arid and arid zones) led to an unexpected 88% increase in trait diversity. This threshold appeared in the presence of grazers, and moved toward lower aridity levels with increasing grazing pressure. Moreover, 57% of observed trait diversity occurred only in the most arid and grazed drylands, highlighting the phenotypic uniqueness of these extreme environments. Our work indicates that drylands act as a global reservoir of plant phenotypic diversity and challenge the pervasive view that harsh environmental conditions reduce plant trait diversity8-10. They also highlight that many alternative strategies may enable plants to cope with increases in environmental stress induced by climate change and land-use intensification.
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Biodiversidad , Clima Desértico , Herbivoria , Fenotipo , Plantas , Plantas/clasificación , Plantas/anatomía & histología , Animales , Ganado , Cambio ClimáticoRESUMEN
The development of biocompatible wound dressings containing therapeutic agents to accelerate wound healing is an interesting field of study in biomedical sciences. Polyvinyl alcohol (PVA) nanofibers were loaded with zinc oxide nanoparticles (ZnO NPs) and curcumin (Cur) through electrospinning. The dressings were characterized by SEM and XRD and FTIR. The antioxidant, antibacterial, and cytotoxic activities Cur/ZnO/PVA nano dressing were evaluated using DPPH radical scavenging assay, disc diffusion method, and MTT assay, respectively. Cur/ZnO/PVA nano dressing showed sustained Cur release about 19.7% and 61.1% after 8h and 168h, respectively. Cur/ZnO NPs/PVA mixture had higher antioxidant potential than PVA, ZnO NPs, and Cur. The dressing showed a good antibacterial effect. The in vivo wound healing effect of different types of prepared dressings, including PVA, Cur/PVA, Cur/ZnO/PVA, and ZnO/ PVA nanofibers, was also investigated. PVA dressing containing Cur/ZnO NPs resulted in the highest increase of wound contraction in rats. The assembly of Cur and ZnO NPs on PVA nanofibers could propose as an effective delivery method to improve the wound healing process. The investigated wound dressing could be commercialized and used on a large scale after proper further studies, including clinical trials.
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Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in drylands, remain virtually unknown. Here we evaluated the relative importance of grazing pressure and herbivore type, climate and plant functional traits on 24 soil physical and chemical attributes that represent proxies of key ecosystem services related to decomposition, soil fertility, and soil and water conservation. To do this, we conducted a standardized global survey of 288 plots at 88 sites in 25 countries worldwide. We show that aridity and plant traits are the major factors associated with the magnitude of plant effects on fertile islands in grazed drylands worldwide. Grazing pressure had little influence on the capacity of plants to support fertile islands. Taller and wider shrubs and grasses supported stronger island effects. Stable and functional soils tended to be linked to species-rich sites with taller plants. Together, our findings dispel the notion that grazing pressure or herbivore type are linked to the formation or intensification of fertile islands in drylands. Rather, our study suggests that changes in aridity, and processes that alter island identity and therefore plant traits, will have marked effects on how perennial plants support and maintain the functioning of drylands in a more arid and grazed world.
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Herbivoria , Suelo , Suelo/química , Plantas , Ecosistema , Clima Desértico , AnimalesRESUMEN
Theranostics nanoparticles (NPs) have recently received much attention in cancer imaging and treatment. This study aimed to develop a multifunctional nanosystem for the targeted delivery of photothermal and chemotherapy agents. Fe3O4 NPs were modified with polydopamine, bovine serum albumin, and loaded with DOX via a thermal-cleavable Azo linker (Fe3O4@PDA@BSA-DOX). The size of Fe3O4@PDA@BSA NPs was approximately 98 nm under the desired conditions. Because of the ability of Fe3O4 and PDA to convert light into heat, the temperature of Fe3O4@PDA@BSA NPs increased to approximately 47 °C within 10 min when exposed to an 808 nm NIR laser with a power density of 1.5 W/cm2. The heat generated by the NIR laser leads to the breaking of AZO linker and drug release. In vivo and in vitro results demonstrated that prepared NPs under laser irradiation successfully eradicated tumor cells without any significant toxicity effect. Moreover, the Fe3O4@PDA@BSA NPs exhibited the potential to function as a contrasting agent. These NPs could accumulate in tumors with the help of an external magnet, resulting in a significant enhancement in the quality of magnetic resonance imaging (MRI). The prepared novel multifunctional NPs seem to be an efficient system for imaging and combination therapy in melanoma.
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Compuestos Férricos , Indoles , Melanoma , Polímeros , Humanos , Melanoma/tratamiento farmacológico , Terapia Fototérmica , Medicina de Precisión , Fototerapia/métodos , Doxorrubicina/farmacología , Doxorrubicina/uso terapéutico , Rayos LáserRESUMEN
Several studies have revealed that healthcare nanomaterials are widely used in numerous areas of dentistry, including prevention, diagnosis, treatment, and repair. Nanomaterials in dental cosmetics are utilized to enhance the efficacy of toothpaste and other mouthwashes. Nanoparticles are added to toothpastes for a variety of reasons, including dental decay prevention, remineralization, hypersensitivity reduction, brightening, and antibacterial qualities. In this review, the benefits and uses of many common nanomaterials found in toothpaste are outlined. Additionally, the capacity and clinical applications of nanoparticles as anti-bacterial, whitening, hypersensitivity, and remineralizing agents in the treatment of dental problems and periodontitis are discussed.
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BACKGROUND: Acne is a common skin issue that typically occurs during adolescence. It causes long-lasting redness and swelling in the skin. An alternative approach to treating acne could involve using a cosmetic facial mask containing herbal ingredients such as Curcumin and Rosa Damascena extract for its antibacterial properties. AIMS: This study aims to create and try out a peel-off mask gel made from Curcumin and R. Damascena extract. This gel is intended to have the ability to kill bacteria such as Staphylococcus aureus, Escherichia coli, and Propionibacterium acnes and remove dead cells from the skin surface. METHODS: The peel-off mask was made using polyvinyl alcohol (PVA) in 8% and 10% as solidifier. The evaluation of peel-off masks comprises the examination of physiochemical and mechanical aspects. Furthermore, their longevity, effectiveness, and antibacterial properties are also considered. RESULTS: The white color, pleasant smell, and soft texture were the defining features of the peel-off gel mask. The changes in PVA affect the pH level, thickness, and how quickly the peel-off mask dries. The stability test found that the peel-off mask had no significant physical changes when exposed to freezing and thawing. However, there were some differences in color and separation when using the real-time method. A prepared peel-off mask containing 10% PVA and curcumin works best against P. acne. The amount of PVA in the formula affected the physical and chemical qualities, but it did not impact on the antibacterial abilities of the peel-off mask gel. The best formula that gives the best results uses 10% PVA + curcumin. CONCLUSIONS: Using the Curcumin and R. Damascena extract in the creation of the peel-off mask gel ensures its efficacy and safety for skin application.
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Acné Vulgar , Antibacterianos , Antioxidantes , Curcumina , Extractos Vegetales , Rosa , Staphylococcus aureus , Curcumina/farmacología , Curcumina/administración & dosificación , Extractos Vegetales/farmacología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Rosa/química , Humanos , Antibacterianos/farmacología , Antibacterianos/administración & dosificación , Antioxidantes/farmacología , Antioxidantes/administración & dosificación , Acné Vulgar/tratamiento farmacológico , Acné Vulgar/microbiología , Staphylococcus aureus/efectos de los fármacos , Propionibacterium acnes/efectos de los fármacos , Alcohol Polivinílico/química , Escherichia coli/efectos de los fármacos , Crema para la Piel/administración & dosificación , Piel/efectos de los fármacos , Piel/microbiología , Pruebas de Sensibilidad MicrobianaRESUMEN
Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought.
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Sequías , Ecosistema , Pradera , Ciclo del Carbono , Cambio Climático , Proteínas Tirosina Quinasas ReceptorasRESUMEN
Assisted reproductive technologies are key to solving the problems of aging and organ defects. Collagen is compatible with living tissues and has many different chemical properties; it has great potential for use in reproductive medicine and the engineering of reproductive tissues. It is a natural substance that has been used a lot in science and medicine. Collagen is a substance that can be obtained from many different animals. It can be made naturally or created using scientific methods. Using pure collagen has some drawbacks regarding its physical and chemical characteristics. Because of this, when collagen is processed in various ways, it can better meet the specific needs as a material for repairing tissues. In simpler terms, collagen can be used to help regenerate bones, cartilage, and skin. It can also be used in cardiovascular repair and other areas. There are different ways to process collagen, such as cross-linking it, making it more structured, adding minerals to it, or using it as a carrier for other substances. All of these methods help advance the field of tissue engineering. This review summarizes and discusses the current progress of collagen-based materials for reproductive medicine.