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1.
Free Radic Res ; 58(1): 43-56, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38165076

RESUMEN

Bis(1-methylimidazol-2-yl) diselenide (MeImSe), a derivative of selenoneine, has been examined for bimolecular rate constants for scavenging of various radiolytically and non-radiolytically generated reactive oxygen species (ROS). Further, its potential to show glutathione peroxidase (GPx)-like activity and to protect in vitro models of DNA and lipid against radiation induced strand breakage and lipid peroxidation, respectively were studied. The results confirmed that MeImSe scavenged all major short-lived (hydroxyl radical) and long-lived (peroxyl radical, carbonate radical, nitrogen dioxide radical, hypochlorite and hydrogen peroxide) oxidants involved in the radiation toxicity either directly or through GPx-like catalytic mechanism. The rate constants of MeImSe for these oxidants were found to be comparable to analogous sulfur and selenium-based compounds. The enzyme kinetics study established that MeImSe took part in the GPx cycle through the reductive pathway. Further, MeImSe inhibited the radiation induced DNA strand cleavage and lipid peroxidation with half maximal inhibitory concentration (IC50) of ∼ 60 µM and ∼100 µM, respectively. Interestingly, MeImSe treatment in the above concentration range (>100 µM) did not show any significant toxicity in normal human lung fibroblast (WI26) cells. The balance between efficacy and toxicity of MeImSe as a chemical radioprotector was attributed to the formation of less reactive intermediates during its oxidation/reduction reactions as evidenced from NMR studies.HighlightsMeImSe, a derivative of selenoneine protects DNA and lipid from radiation damageMeImSe scavenges all major short- and long-lived oxidants involved in radiation toxicityRate constants of MeImSe for ROS scavenging determined by pulse radiolysis techniqueFirst organoselenium compound reported to scavenge nitrogen dioxide radicalMeImSe exhibits GPx-like activity through reductive pathway.


Asunto(s)
Antioxidantes , Histidina/análogos & derivados , Compuestos de Organoselenio , Humanos , Antioxidantes/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Glutatión Peroxidasa/metabolismo , Dióxido de Nitrógeno , Compuestos de Organoselenio/química , Peroxidación de Lípido , ADN/metabolismo , Oxidantes , Lípidos , Oxidación-Reducción
2.
J Ayurveda Integr Med ; 14(6): 100804, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37847964

RESUMEN

BACKGROUND: The polyherbal formulation (PHF) liberin, is known to exert anti-hyperglycemic effects in type 2 diabetes mellitus. Hence, it is important to study the safety profile of PHF in the current study through acute and chronic toxicity evaluation. OBJECTIVES: This research aims to assess the acute and sub-chronic toxicity of PHF in rats. MATERIALS AND METHODS: PHF was administered once orally (1000 mg/kg body weight), and the rats (male and female) were monitored for toxicity signs for a 14-day period. For a 28-day chronic toxicity study, rats were daily administered with PHF dose of 500 mg/kg and 1000 mg/kg body weight. Rats were followed up for mortality, weight changes, and other morbidities. Further haematological, biochemical, and histopathological changes were assessed. RESULTS: No death related to treatment or toxicity signs were recorded in the acute single-dose administration group. The results showed that the PHF was tolerated well up to a dose of 1000 mg/kg body weight. Even at the high dose of 1000 mg/kg body weight, sub-chronic tests did not show any significant difference between the dosed and normal groups. No significant changes were seen in the histopathological analysis of the liver, spleen, and kidney as well as haematological and biochemical parameters in acute, sub-chronic and satellite groups following the administration of PHF. CONCLUSION: The results confirmed that there was no adverse effect of this PHF at the maximum dose of 1000 mg/kg body weight in Wistar rats. Further, no adverse delayed effects related to PHF were observed in the satellite group. Therefore, this PHF appears safe for therapeutic purposes in the Ayurvedic medicinal system.

3.
Sensors (Basel) ; 23(20)2023 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-37896556

RESUMEN

MXenes are a new family of two-dimensional (2D) nanomaterials. They are inorganic compounds of metal carbides/nitrides/carbonitrides. Titanium carbide MXene (Ti3C2-MXene) was the first 2D nanomaterial reported in the MXene family in 2011. Owing to the good physical properties of Ti3C2-MXenes (e.g., conductivity, hydrophilicity, film-forming ability, elasticity) various applications in wearable sensors, energy harvesters, supercapacitors, electronic devices, etc., have been demonstrated. This paper presents the development of a piezoresistive Ti3C2-MXene sensor followed by experimental investigations of its dynamic response behavior when subjected to structural impacts. For the experimental investigations, an inclined ball impact test setup is constructed. Stainless steel balls of different masses and radii are used to apply repeatable impacts on a vertical cantilever plate. The Ti3C2-MXene sensor is attached to this cantilever plate along with a commercial piezoceramic sensor, and their responses for the structural impacts are compared. It is observed from the experiments that the average response times of the Ti3C2-MXene sensor and piezoceramic sensor are 1.28±0.24µs and 31.19±24.61µs, respectively. The fast response time of the Ti3C2-MXene sensor makes it a promising candidate for monitoring structural impacts.

5.
J Ayurveda Integr Med ; 13(3): 100583, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35759880

RESUMEN

BACKGROUND: Ayurveda is a holistic system of medicine and describes a vast array of herbs and herbal mixtures that are been demonstrated to possess efficacy in research investigations. Guggulutikthaka gritha (GTG) is one such drug evaluated for its role in skin and bone diseases. OBJECTIVE: In the current study, the hypoglycemic, hypolipidemic, and anti-inflammatory effect of the drug GTG was studied with the scope to treat dyslipidemia and thereby reduce the risk of cardiovascular disease. MATERIALS AND METHOD: The animals (Wistar rats) were fed a high-fat diet and dyslipidemia was induced. The control group was provided with a normal chow diet and had free access to water. The treatment with the drug GTG was given for 21 days after confirming dyslipidemia. The blood glucose was measured immediately using a glucometer. The serum was analyzed for lipid profile and Vascular Cell Adhesion Molecule - 1(VCAM 1) by ELISA method before and after treatment. The histopathology of the heart and liver was also performed. RESULTS: The abnormal change in lipid profile, blood glucose, and inflammatory marker along with the accumulation of intracellular fats in the arteries of the heart and liver confirmed dyslipidemia. A significant reduction in serum lipid profile (p < 0.05), blood glucose (p < 0.05), and VCAM 1 (p < 0.05) was noted after the treatment with significant histopathological changes in arteries of the heart and liver. CONCLUSION: The study provides scientific validation on the drug GTG being effective in hyperglycemia, hyperlipidemia, and inflammation in dyslipidemia.

6.
Nanotechnology ; 32(50)2021 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-34517349

RESUMEN

Flexible strain sensors are emerging rapidly and overcoming the drawbacks of traditional strain sensors. However, many flexible sensors failed to balance the sensitivity, response time, and the desired sensing range. This work proposes a novel and cost-effective strain sensor which simultaneously achieved high sensitivity, fast response, and a good sensing range. It illustrates a prototype strain sensor realized with a nanocomposite constituting reduced graphene oxide and palladium as the primary sensing elements. These sensors were fabricated with manual screen-printing technology. The sensor exhibited an outstanding performance for the different strains ranging from 0.1% to 45%. As a result, a substantially high gauge factor around 1523 at a strain of as high as 45% and a rapid response time of 47 ms was obtained. This work demonstrated potential applications like real-time monitoring of pulse and respiration, and other physical movement detection, which become crucial parameters to be measured continuously during the COVID-19 pandemic.

7.
Int J Prev Med ; 12: 16, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34084313

RESUMEN

The world is full of data which is increasing by leaps and bounds. In health care, big data is becoming common with increased electronic health data accumulation and/or accessibility to public data previously held under lock and key. At the same time, health data visualization applications have become popular over recent years. Against this background, a review was done to summarize the application of data visualization in public health & the challenges faced. Peer-reviewed original research articles and review articles searched in Google Scholar and Pubmed databases that were indexed in the last ten years period, using the keywords "Big data" or "data visualization" or "Interactive visualization techniques." Other related information in books, blogs, and published documents were searched in Google search engine using the same keywords. Contents from the downloaded documents were presented and discussed under three headings viz. (a) the visualizations that are still current and how they have evolved further, (b) tools or methods that can be used by end-users to make their own modifications, (c) the platforms to disseminate them. Usage of different plots in public health is explained with suitable examples using the data from public health datasets. From the discussion it can be understood that when big data is visualized well, it can identify implementation gaps and disparities and accelerate implementation strategies to reach the population groups in most need for interventions. As health administrator may come from diverse specialties, robust training and career development for big data in public health is the need of the hour.

8.
Int J Nephrol Renovasc Dis ; 14: 23-31, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33603439

RESUMEN

PURPOSE: Diabetic kidney disease (DKD) represents a unique subset of patients with chronic kidney disease (CKD). Acute kidney injury (AKI) is implicated in DKD progression; however, their interplay is not studied well. We studied risk factors for AKI and the effect of AKI on disease progression in a homogeneous group of patients with DKD. PATIENTS AND METHODS: We conducted a retrospective open cohort study of patients with DKD at a single tertiary care centre between August 2016 - August 2019. Patients with a minimum follow-up of 2 years were included in the study. The incidence, etiology and risk factors for AKI were studied. The primary outcome studied was the effect of AKI on reduction in estimated glomerular filtration rate (eGFR) in DKD. Loss in eGFR by 50% and need for renal replacement therapy or reaching CKD stage V were studied as secondary outcomes. RESULTS: Two hundred and ninety-two DKD patients meeting the study criteria with a follow-up of 29.57 (±4.3) months were included. The incidence of AKI was 31.1%. Sepsis was the most common etiology (61%). Proteinuria was an independent risk factor for AKI after adjusting for covariates (adjusted OR - 1.158; 95% CI (1.018-1.316); p=0.025). In patients with AKI, median decline in eGFR was 10.29 mL/min/1.73m2/year (IQR-5.58-13.84) which was significantly higher compared to patients with no AKI [eGFR 7.25 (IQR 5.06-11.38); p-0.014]. On subgroup analysis, sepsis-induced AKI (versus non-sepsis AKI; p<0.001) and higher AKI stage (stage 2/3 versus stage 1; p=0.019) were associated with a faster decline in eGFR. CONCLUSION: AKI is common in patients with DKD with sepsis being the most common etiology. AKI in diabetic kidney disease is associated with a faster decline in eGFR. Baseline proteinuria is an independent risk factor for AKI.

9.
10.
RSC Adv ; 10(49): 29147-29155, 2020 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35521094

RESUMEN

MXenes (Titanium Carbide, Ti3C2-MXene) are two-dimensional nanomaterials that are known for their conductivity, film-forming ability, and elasticity. Though literature reports the possibility of usage of Ti3C2-MXenes for sensor development, the material properties and response need be studied in detail for designing sensors to measure dynamic variables like force, displacement, etc., in a dynamic environment. Ti3C2-MXenes due to their good electro-mechanical properties can be used for manufacturing sensing elements for engineering and biomedical applications. This paper focuses on an investigation of the dynamic response properties of Ti3C2-MXenes subjected to shockwave and impact forces. A supersonic shockwave (Mach number: 1.68, peak overpressure: 234.3 kPa) produced in a shock tube acts as an external force on the Ti3C2-MXene film placed inside the shock tube. In the experiment performed, the response time of the Ti3C2-MXene film sample has been observed to be in the range of few microseconds (∼7 µs) for the high-velocity shock. In a separate experiment, Ti3C2-MXene film samples are subjected to low-velocity impact forces through a ball drop test. The results from the ball drop test provide a response time in the range of few milliseconds (average ∼1.5 ms). In this novel demonstration, the Ti3C2-MXene film sample responds well for both low-velocity mechanical impact as well as high-velocity shockwave impact. Further, the repeatability of the dynamic response of the Ti3C2-MXene film sample is discussed along with its significant piezoresistive behavior. This work provides the basis for sensor development to measure the dynamic phenomena of pressure changes, acoustic emissions, structural vibrations, etc.

11.
Nanotechnology ; 31(3): 035501, 2020 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-31557751

RESUMEN

We report a novel strain sensor based on reduced graphene oxide (rGO) with palladium (Pd) nano-composite. The sensor was fabricated on the SS304 stainless-steel substrate using a screen-printing method. Graphene oxide was synthesized using a modified Hummer's method and reduced using a chemical route. Field emission-scanning electron microscope, x-ray diffraction and Raman spectroscopy were used to characterize the as-synthesized nano-composite. The as-fabricated strain sensor was tested for tensile strain using Micro-universal Test Machine and the change in resistance for different strains was recorded. The sensor response was observed to be stable and linear within the applied strain range of 0-3000 microstrains, and an average gauge factor of 42.69 was obtained in this range.

12.
Musculoskelet Surg ; 104(1): 67-74, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30937858

RESUMEN

OBJECTIVES: Anterior cruciate ligament (ACL) rupture is a common injury and has a non-union rate of 40-100%. Important cellular events, such as fibroblast proliferation, angiogenesis and change in collagen fibril thickness in the ACL remnant, as described in other dense connective tissue, might have an implication in graft recovery following ACL reconstruction. Thus we conducted a study with an aim to characterize the ultrastructural and histological features of ruptured ACL tibial stump and correlate the same with the duration of injury. MATERIALS AND METHODS: This was a prospective observational study in which 60 ruptured human ACLs were evaluated for collagen fibril thickness, blood vessel density (per mm2) and fibroblast density (per mm2) with the help of transmission electron microscopy, immunohistochemistry via CD34 antibody staining and light microscopy (H&E staining). The findings were correlated with duration of injury. RESULTS: Fifty-four male and six female patients with a mean duration of the injury of 23.01 weeks (SD = 26.09; range 2-108 weeks) were included for the study and were divided on the basis of duration of injury as follows: Group I (≤ 6 weeks; N = 16), Group II (7-12 weeks; N = 18), Group III (13-20 weeks; N = 7), Group IV (21-50 weeks; N = 12), Group V (> 50 weeks; N = 7). A significant correlation was seen with blood vessel density (r = 0.303, p = 0.01) and fibroblast density (r = - 0.503, p = 0.001). Thickness of collagen fibril did not correlate with the duration of injury (r = 0.15, p = 0.23). The thickness of the collagen reached its peak after 50 weeks following injury, whereas highest density of blood vessel and fibroblast was seen at 12-20 weeks. Matched pair analysis revealed a significant decrease in collagen fibril thickness and an increase in fibroblast density at 7-12 weeks. CONCLUSION: Following injury to ACL, the ruptured tibial stump undergoes a series of changes at the cellular level vis-à-vis changes in collagen fibril thickness, vascular density and fibroblast density that possibly suggest an intrinsic healing response. This further may have implications on the functional outcome following ACL reconstruction with remnant preservation. LEVEL OF EVIDENCE: III.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior/patología , Ligamento Cruzado Anterior/ultraestructura , Rotura/patología , Adolescente , Adulto , Femenino , Humanos , Inmunohistoquímica , Masculino , Microscopía Electrónica de Transmisión , Estudios Prospectivos , Adulto Joven
13.
Comput Methods Programs Biomed ; 186: 105131, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31733519

RESUMEN

BACKGROUND: The present work provides important insights regarding three dimensional unsteady magnetohydrodynamic flow and entropy generation of micropolar Casson Cross nanofluid subject to nonlinear thermal radiation and chemical reaction. The Buongiorno's nanofluid model featured with Brownian movement and thermophoresis is considered. Realistic aspects namely convective boundary condition, viscous dissipation and joule heating are introduced. The present problem is modeled by momentum, temperature, microrotation and nanoparticles concentration equations. METHOD: The non-dimensional highly nonlinear differential equations are solved numerically via shooting iteration technique together with 4th order Runge-Kutta integration scheme. RESULTS: The current study imparts a reasonable, pragmatic and realistic approach to a good absorber of solar energy. In addition, strong and visionary profiles of velocity, microrotation, temperature, nanoparticles concentration, entropy generation rate and Bejan number for concern nanofluids are presented. Besides, intensive physical interpretation of the involved thermophycal parameters has been well-addressed. CONCLUSIONS: The present investigation shows that strengthening of Weissenberg number uplifts the axial as well transverse fluid velocities while that of Hartmann number turns out to be a reverse trend. Furthermore, heat and mass transfer rates exhibit ascending and descending trends for intensified Brownian motion and thermophoresis respectively. Improved thermal boundary layer due to the upgrading temperature ratio parameter is another outcome of the current analysis.


Asunto(s)
Entropía , Calor , Nanoestructuras , Energía Solar , Viscosidad , Algoritmos , Modelos Teóricos
14.
Nanotechnology ; 30(47): 475502, 2019 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-31430732

RESUMEN

This paper presents development and performance assessment of an innovative and a highly potent graphene-electrolyte capacitive sensor (GECS) based on the supercapacitor model. Although graphene has been widely researched and adapted in supercapacitors as electrode material, this combination has not been applied in sensor technology. A low base capacitance, generally the impeding factor in capacitive sensors, is addressed by incorporating electric double layer capacitance in GECS, and a million-fold increase in base capacitance is achieved. The high base capacitance (∼22.0 µF) promises to solve many inherent issues pertaining to capacitive sensors. GECS is fabricated by using thermally reduced microwave exfoliated graphene oxide material to form interdigitated electrodes coated with solid-state electrolyte which forms the double layer capacitance. The capacitance response of GECS on subjecting to strain is examined and an enormous operating range (∼300 nF) is seen, which is the salient feature of this sensor. The GECS showed an impressive device sensitivity of 11.24 nF kPa-1 and good immunity towards noise i.e. lead capacitance and stray capacitance. Two regimes of operation are identified based on the procedure of device fabrication. The device can be applied to varied applications and one such biomedical application of breath pattern monitoring is demonstrated.


Asunto(s)
Tecnología Biomédica/instrumentación , Capacidad Eléctrica , Electrólitos/química , Grafito/química , Simulación por Computador , Microondas , Nanopartículas/química , Oxidación-Reducción , Espectrometría Raman , Difracción de Rayos X
15.
Small ; : e1800608, 2018 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-29939479

RESUMEN

Crash sensing and its assessment play a pivotal role in autonomous vehicles for preventing fatal casualties. Existing crash sensors are severely bottlenecked by sluggish response time, rigid mechanical components, and space constraints. Miniaturized sensors embedded with custom-tailored nanomaterials upholds potential to overcome these limitations. In this article, piezoelectric Zinc-Oxide thin film as a crash sensing layer is integrated onto a flexible metal-alloy cantilever. Material characterization studies are conducted to confirm piezoelectric property of sputtered ZnO film. The piezoelectric d 31 coefficient value of ZnO film was 7.2 pm V-1 . The ZnO sensing element is firmly mounted on a scaled car model and used in a crash sensing experimental set-up. A comprehensive theoretical analysis for two different real scenarios (nearly elastic and nearly inelastic collision) of crash events followed by experimental study is discussed. The crash sensor's output exhibits a linear relationship with magnitude of impact forces experienced at crash events. The response time of ZnO crash sensor is 18.2 ms, and it exhibits a sensitivity of 28.7 mV N-1 . The developed crash sensor has potential to replace bulk material sensors owing to its faster response time, high sensitivity, and compactness as the demand for crash sensors in next-generation automobile industries is progressively growing.

16.
Rev Sci Instrum ; 88(1): 015102, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28147679

RESUMEN

Micropump technology has evolved significantly in the last two decades and is finding a variety of applications ranging from µTAS (micro Total Analysis System) to drug delivery. However, the application area of the micropump is limited owing to: simple pumping mechanism, ease of handling, controlled (microliter to milliliter) delivery, continuous delivery, and accuracy in flow rate. Here, the author presents the design, development, characterization, and precision flow controlling of a DC-motor driven peristaltic pump for controlled drug delivery application. All the micropump components were fabricated using the conventional fabrication technique. The volume flow variation of the pump has been characterized for different viscous fluids. The change in volume flow due to change in back pressure has been presented in detail. The fail-safe mode operation of the pump has been tested and leak rate was measured (∼0.14% leak for an inlet pressure of 140 kPa) for different inlet pressures. The precision volume flow of the pump has been achieved by measuring the pinch cam position and load current. The accuracy in the volume flow has been measured after 300 rotations. Finally, the complete system has been integrated with the necessary electronics and an android application has been developed for the self-administration of bolus and basal delivery of insulin.


Asunto(s)
Sistemas de Liberación de Medicamentos/instrumentación , Bombas de Infusión , Microfluídica , Sistemas de Liberación de Medicamentos/métodos , Diseño de Equipo
17.
Psychooncology ; 26(8): 1087-1092, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28040884

RESUMEN

BACKGROUND: Expansion of medical marijuana (MM) laws in the United States may offer oncology new therapeutic options. However, the scientific evidence for MM remains in infancy. This study qualitatively explored professional opinion around the role of MM in cancer care. METHODS: Semistructured interviews were administered to a sample of individuals with expertise at the interface of MM and oncology nationally. Key informant criteria included an oncologic clinical or research background and any of the following: publications, research, or lectures on cannabinoids or cancer symptoms; involvement in the development of MM dispensaries or legislation; and early adoption of state MM certification procedures. A gold standard, grounded, inductive approach was used to identify underlying themes. RESULTS: Participants (N = 15) were predominantly male, in their sixth decade, working in academic settings. Themes ranged from strong beliefs in marijuana's medical utility to reservations about this notion, with calls for expansion of the scientific evidence base and more stringent MM production standards. All participants cited nausea as an appropriate indication, and 13 of 15 pain. Over one-third believed MM to have a more attractive risk profile than opioids and benzodiazepines. CONCLUSIONS: Expert opinion was divided between convictions in marijuana's medicinal potential and guardedness in this assertion, with no participant refuting MM's utility outright. Emergent themes included that MM ameliorates cancer-related pain and nausea and is safer than certain conventional medications. Participants called for enhanced purity and production standards, and further research on MM's utility.


Asunto(s)
Cannabinoides/uso terapéutico , Marihuana Medicinal/uso terapéutico , Oncología Médica , Neoplasias/tratamiento farmacológico , Humanos , Masculino , Náusea/prevención & control , Sociedades Médicas , Nivel de Atención , Estados Unidos
18.
J Thromb Haemost ; 15(2): 388-394, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27943541

RESUMEN

Essentials The main receptor for platelet glycoprotein (GP) Ibα is von Willebrand factor (VWF). P-selectin and thrombospondin-1 (TSP1) have been suggested as counter receptors for GPIbα. In a laser injury model, P-selectin promotes thrombus propagation independently of VWF and TSP1. In a laser injury model, thrombus persists in interleukin-4 receptor α/GPIbα-transgenic mice. SUMMARY: Background P-selectin and thrombospondin-1 (TSP1) have been suggested as counter ligands that may mediate GPIbα-dependent thrombus growth independently of von Willebrand factor (VWF) in vitro. However, residual thrombus formation still persists in Vwf -/- Tsp1-/- mice, suggesting existence of other mechanisms that modulate thrombus propagation. Objective We determined whether P-selectin modulates thrombus propagation in injured arterioles independently of TSP1 and VWF. Methods CD-62P blocking antibody in Vwf -/- Tsp1-/- mice was used to inhibit P-selectin. We determined thrombus growth kinetics in two models of thrombosis: FeCl3 injury-induced and laser injury-induced thrombosis. Results In a 10% FeCl3 injury-induced thrombosis model, the initial platelet adhesion, time to form first thrombus, and non-occlusive residual thrombus growth kinetics were comparable between P-selectin-blocking antibody-treated Vwf -/- Tsp1-/- mice and control IgG-treated Vwf -/- Tsp1-/- mice. On the other hand, in a laser injury-induced thrombosis model, residual thrombus growth kinetics were significantly decreased in P-selectin-blocking antibody-treated Vwf -/- Tsp1-/- mice vs. control IgG-treated Vwf -/- Tsp1-/- mice. Because P-selectin has been suggested as a counter ligand for platelet GPIbα, we determined the role of GPIbα in a laser injury-induced thrombosis model. Surprisingly, in a laser injury model, unlike in a FeCl3 injury model, thrombus formation was not completely inhibited in IL4Rα/GPIbα-tg mice. Residual thrombus growth kinetics were comparable between P-selectin-blocking antibody-treated IL4Rα/GPIbα-tg mice and control IgG-treated IL4Rα/GPIbα-tg mice. Comparison of slopes over time showed that residual thrombus growth kinetics were comparable in P-selectin-blocking antibody-treated Vwf -/- Tsp1-/- and control IgG-treated IL4Rα/GPIbα-tg mice Conclusion In a laser injury-induced thrombosis model, P-selectin modulates thrombus propagation independently of VWF and TSP1.


Asunto(s)
Selectina-P/metabolismo , Trombosis/metabolismo , Trombospondina 1/metabolismo , Factor de von Willebrand/metabolismo , Animales , Anticoagulantes/farmacología , Plaquetas/metabolismo , Cloruros/química , Modelos Animales de Enfermedad , Compuestos Férricos/química , Inmunoglobulina G/metabolismo , Rayos Láser , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Activación Plaquetaria , Adhesividad Plaquetaria/efectos de los fármacos , Unión Proteica
19.
AAPS PharmSciTech ; 18(6): 2085-2094, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28004342

RESUMEN

The dissolution and subsequent oral bioavailability of acyclovir (ACY) is limited by its poor aqueous solubility. An attempt has been made in this work to provide mechanistic insights into the solubility enhancement and dissolution of ACY by using the water-soluble carrier polyethylene glycol 6000 (PEG6000). Solid dispersions with varying ratios of the drug (ACY) and carrier (PEG6000) were prepared and evaluated by phase solubility, in vitro release studies, kinetic analysis, in situ perfusion, and in vitro permeation studies. Solid state characterization was done by powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) analysis, and surface morphology was assessed by polarizing microscopic image analysis, scanning electron microscopy, atomic force microscopy, and nuclear magnetic resonance analysis. Thermodynamic parameters indicated the solubilization effect of the carrier. The aqueous solubility and dissolution of ACY was found to be higher in all samples. The findings of XRD, DSC, FTIR and NMR analysis confirmed the formation of solid solution, crystallinity reduction, and the absence of interaction between the drug and carrier. SEM and AFM analysis reports ratified the particle size reduction and change in the surface morphology in samples. The permeation coefficient and amount of ACY diffused were higher in samples in comparison to pure ACY. Stability was found to be higher in dispersions. The results suggest that the study findings provided clear mechanical insights into the solubility and dissolution enhancement of ACY in PEG6000, and such findings could lay the platform for resolving the poor aqueous solubility issues in formulation development.


Asunto(s)
Aciclovir/síntesis química , Aciclovir/metabolismo , Portadores de Fármacos/síntesis química , Portadores de Fármacos/metabolismo , Aciclovir/farmacología , Animales , Antivirales/síntesis química , Antivirales/metabolismo , Antivirales/farmacología , Disponibilidad Biológica , Rastreo Diferencial de Calorimetría/métodos , Portadores de Fármacos/farmacología , Absorción Intestinal/efectos de los fármacos , Absorción Intestinal/fisiología , Cinética , Masculino , Microscopía Electrónica de Rastreo/métodos , Polietilenglicoles/síntesis química , Polietilenglicoles/metabolismo , Polietilenglicoles/farmacología , Ratas , Ratas Sprague-Dawley , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Difracción de Rayos X/métodos
20.
Nat Commun ; 7: 12591, 2016 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-27575002

RESUMEN

The Martian satellite Phobos is criss-crossed by linear grooves and crater chains whose origin is unexplained. Anomalous grooves are relatively young, and crosscut tidally predicted stress fields as Phobos spirals towards Mars. Here we report strong correspondence between these anomalous features and reaccretion patterns of sesquinary ejecta from impacts on Phobos. Escaping ejecta persistently imprint Phobos with linear, low-velocity crater chains (catenae) that match the geometry and morphology of prominent features that do not fit the tidal model. We prove that these cannot be older than Phobos' current orbit inside Mars' Roche limit. Distinctive reimpact patterns allow sesquinary craters to be traced back to their source, for the first time across any planetary body, creating a novel way to probe planetary surface characteristics. For example, we show that catena-producing craters likely formed in the gravity regime, providing constraints on the ejecta velocity field and knowledge of source crater material properties.

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