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A significantly high protease enzyme yield of 617 U/ml was achieved with Acinetobacter pittii as the microorganism and peanut oil meal as the substrate. Peanut oil meal, which consists of proteins (40-60%) and carbohydrates (22-30%), serves as a sufficient source of nitrogen and carbon necessary for microbial growth and production of enzymes. Moreover, peanut meal offers the advantages of being affordable and available in large quantities, making the meal suitable for cost-effective enzyme production. In the present study, two bacterial strains and one fungal strain were selected to produce proteases utilizing peanut oil meal as the substrate. The experimental conditions during the enzyme production, including pH and temperature, were optimized. In addition, the substrate was enriched with various carbon and nitrogen sources. The microbial strains were streaked on nutritional agar (for bacteria) and potato dextrose agar (for fungus). Following an incubation period, the plates were stored at 4°C for further studies. The molecular weight of partially purified proteases of Acinetobacter pittii was found to be â 95.5â kDa. Potassium nitrate was the most ideal nitrogen source (up to 411% increase in activity) and fructose was the best carbon source (425% increase). These enzymes exhibited excellent temperature tolerance and were capable of functioning over a wide pH range. Furthermore, the obtained proteases demonstrated ability to coagulate milk effectively, indicating their potential for various food-related applications.
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INTRODUCTION: Hyponatraemia is the most common electrolyte disorder in inpatients resulting mainly from an imbalance in water homeostasis. Intravascular fluid status assessment is pivotal but is often challenging given multimorbidity, polypharmacy and diuretics use. We evaluated the utility of point-of-care ultrasound (POCUS) as an adjunct tool to standard practice for fluid assessment in severe hyponatraemia patients. METHODS: Patients presenting with severe hyponatremia (Serum Sodium [Na] < 120 mmol/L; Normal range: 135-145 mol/L), managed by standard care were included. Hyponatraemia biochemistry work-up and POCUS examination were undertaken. Both clinician and POCUS independently assigned one of the three fluid status groups of hypovolaemia, hypervolaemia or euvolaemia. The final diagnosis of three fluid status groups at admission was made at the time of discharge by retrospective case review. Clinician's (standard of care) and POCUS fluid assessments were compared to that of the final diagnosis at the time of discharge. RESULTS: n = 19 patients were included. Median Na on admission was 113 mmol/L (109-116), improved to 129 ± 3 mmol/L on discharge. POCUS showed the higher degree of agreement with the final diagnosis (84%; n = 16/19), followed by the clinician (63%; n = 12/19). A trend towards higher accuracy of POCUS compared to clinician assessment of fluid status was noted (84% vs. 63%, p = 0.1611). Biochemistry was unreliable in 58% (n = 11/19) likely due to renal failure, polypharmacy or diuretic use. Inappropriate emergency fluid management was undertaken in 37% (n = 7/19) of cases based on initial clinician assessment. Thirst symptom correlated to hypovolaemia in 80% (4/5) cases. CONCLUSION: As subjective clinical and biochemistry assessments of fluid status are often unreliable due to co-morbidities and concurrent use of medications, POCUS can be a rapid objective diagnostic tool to assess fluid status in patients with severe hyponatraemia, to guide accurate emergency fluid management.
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Hiponatremia , Sistemas de Atención de Punto , Ultrasonografía , Humanos , Hiponatremia/diagnóstico por imagen , Femenino , Masculino , Ultrasonografía/métodos , Anciano , Anciano de 80 o más Años , Persona de Mediana Edad , Estudios Retrospectivos , AdultoRESUMEN
Point-of-care (POC) diagnostic platforms are globally employed in modern smart technologies to detect events or changes in the analyte concentration and provide qualitative and quantitative information in biosensing. Surface plasmon-coupled emission (SPCE) technology has emerged as an effective POC diagnostic tool for developing robust biosensing frameworks. The simplicity, robustness and relevance of the technology has attracted researchers in physical, chemical and biological milieu on account of its unique attributes such as high specificity, sensitivity, low background noise, highly polarized, sharply directional, excellent spectral resolution capabilities. In the past decade, numerous nano-fabrication methods have been developed for augmenting the performance of the conventional SPCE technology. Among them the utility of plasmonic gold nanoparticles (AuNPs) has enabled the demonstration of plethora of reliable biosensing platforms. Here, we review the nano-engineering and biosensing applications of AuNPs based on the shape, hollow morphology, metal-dielectric, nano-assembly and heterometallic nanohybrids under optical as well as biosensing competencies. The current review emphasizes the recent past and evaluates the latest advancements in the field to comprehend the futuristic scope and perspectives of exploiting Au nano-antennas for plasmonic hotspot generation in SPCE technology.
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OBJECTIVE: Elucidate the efficacy (as per current biochemical criteria) of cabergoline monotherapy or as addition to long-acting somatostatin receptor ligand (SRL) in patients with acromegaly and no previous pituitary radiotherapy. DESIGN: Multi-centre, retrospective, cohort study (four UK Pituitary centres: Birmingham, Bristol, Leicester, Oxford). METHODS: Clinical, laboratory, imaging data were analysed. RESULTS: Sixty-nine patients on cabergoline monotherapy were included [median IGF-1 xUpper Limit of Normal (ULN) pre-cabergoline 2.13 (1.02-8.54), median treatment duration 23 months, median latest weekly dose 3 mg]. 31.9% achieved normal IGF-1 (25% GH-secreting, 60% GH+prolactin co-secreting tumours); median weekly cabergoline dose was similar between responders and non-responders. IGF-1 normalisation was related with GH+prolactin co-secreting adenoma (B 1.50, p=0.02) and lower pre-cabergoline IGF-1 xULN levels (B -0.70, p=0.02). Both normal IGF-1 and GH<1 mcg/L were detected in 12.9% of cases and tumour shrinkage in 29.4% of GH-secreting adenomas.Twenty-six patients on SRL+cabergoline were included [median IGF-1 xULN pre-cabergoline 1.7 (1.03-2.92), median treatment duration 36 months, median latest weekly dose 2.5 mg]. 23.1% achieved normal IGF-1 (15.8% GH-secreting, 33.3% GH+prolactin co-secreting tumours). Normal IGF-1 and GH<1 mcg/L were detected in 17.4%. CONCLUSIONS: In non-irradiated patients, cabergoline normalises IGF-1 in around one-third and achieves both IGF-1 and GH targets in approximately one out of ten cases. SRL+cabergoline is less efficient than previously reported possibly due to differences in studies methodology and impact of confounding factors.
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A thin plastic-like film separated from the epidermis of Cereus hildmannianus has excellent tensile strength, resistance to water and high antimicrobial activity and supports the growth of mouse fibroblast cells. Cactuses are one of the most under explored plant species with high potential for food, materials, pharmaceutical and other applications. Although studies have shown the ability of cactuses to be used for food, as a source for fibers, as reinforcement for composites and other applications, the role of individual layers and their properties has been studied to a limited extent. In this paper, a thin translucent layer was separated from the epidermis of C. hildmannianus and studied for its composition, structure and properties. The layer is composed of about 73% cellulose and 2% lignin and morphologically, shows surface with uneven and serrated edges. Films with length of up to 36 cm, strength of 6.8 MPa and elongation of 2.5% could be peeled from the cactus suggesting their suitability for food packaging and other applications. X-ray diffraction patterns and FTIR spectrums indicated that the films are similar to that of cellulose and major thermal degradation occurred above 280°C. Compared to standards, the cactus films showed about 41% and 44% inhibition against gram positive and gram negative bacteria and 67% inhibition of the common fungal strain (A. niger). Films showed high stability in water and to common chemicals. When used as substrates for mouse fibroblast cell growth, no cytotoxicity was observed and the cactus peel supported the attachment and proliferation of cells demonstrating potential to be used as a biomaterial for tissue engineering applications.
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Cactaceae , Ingeniería de Tejidos , Animales , Ratones , Antibacterianos/química , Biomimética , Bacterias Gramnegativas , Bacterias Grampositivas , Celulosa/farmacología , Celulosa/química , Epidermis , Agua/químicaRESUMEN
OBJECTIVE: The optimal approach to the surveillance of non-functioning pituitary microadenomas (micro-NFPAs) is not clearly established. Our aim was to generate evidence on the natural history of micro-NFPAs to support patient care. DESIGN: Multi-centre, retrospective, cohort study involving 23 endocrine departments (UK NFPA consortium). METHODS: Clinical, imaging, and hormonal data of micro-NFPA cases between January, 1, 2008 and December, 21, 2021 were analysed. RESULTS: Data for 459 patients were retrieved [median age at detection 44 years (IQR 31-57)-152 males/307 females]. Four hundred and nineteen patients had more than two magnetic resonance imagings (MRIs) [median imaging monitoring 3.5 years (IQR 1.71-6.1)]. One case developed apoplexy. Cumulative probability of micro-NFPA growth was 7.8% (95% CI, 4.9%-8.1%) and 14.5% (95% CI, 10.2%-18.8%) at 3 and 5 years, respectively, and of reduction 14.1% (95% CI, 10.4%-17.8%) and 21.3% (95% CI, 16.4%-26.2%) at 3 and 5 years, respectively. Median tumour enlargement was 2â mm (IQR 1-3) and 49% of micro-NFPAs that grew became macroadenomas (nearly all >5â mm at detection). Eight (1.9%) patients received surgery (only one had visual compromise with surgery required >3 years after micro-NFPA detection). Sex, age, and size at baseline were not predictors of enlargement/reduction. At the time of detection, 7.2%, 1.7%, and 1.5% patients had secondary hypogonadism, hypothyroidism, and hypoadrenalism, respectively. Two (0.6%) developed hypopituitarism during follow-up (after progression to macroadenoma). CONCLUSIONS: Probability of micro-NFPA growth is low, and the development of new hypopituitarism is rare. Delaying the first follow-up MRI to 3 years and avoiding hormonal re-evaluation in the absence of tumour growth or clinical manifestations is a safe approach for micro-NFPA surveillance.
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Adenoma , Hipopituitarismo , Neoplasias Hipofisarias , Masculino , Femenino , Humanos , Adulto , Persona de Mediana Edad , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/epidemiología , Neoplasias Hipofisarias/complicaciones , Estudios Retrospectivos , Estudios de Cohortes , Adenoma/diagnóstico por imagen , Adenoma/epidemiología , Hipopituitarismo/complicaciones , Reino Unido/epidemiologíaRESUMEN
Wood chips were used in their original form without any physical or chemical treatment as reinforcement for polypropylene to develop composites as potential replacement for medium density fiber (MDF) boards, gypsum based false ceiling and other building materials. Wood chips are generated as byproducts and have limited and low value applications. Composites with up to 90% wood chips were developed through compression molding and the mechanical, acoustic and thermal properties were studied. Further, maleated polypropylene (MAPP) was used (1-5% w/w based on woodchips used) as compatibilizer and changes in properties were recorded. Up to 300% increase in tensile properties were observed when 5% compatibilizer was present. Tensile properties of the composites containing MAPP were higher than that of commercially available medium density plywood boards and also gypsum based ceiling tiles. Addition of MAPP did not change thermal conductivity but decreased sound absorption. Wood chips reinforced PP composites containing MAPP show exceedingly high properties and could replace particle, fiber boards and other building materials in current use. Utilizing the wood waste also results in environmentally friendly, sustainable and low cost building materials.
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Transgenic modification of Bombyx mori silkworms is a benign approach for the production of silk fibers with extraordinary properties and also to generate therapeutic proteins and other biomolecules for various applications. Silk fibers with fluorescence lasting more than a year, natural protein fibers with strength and toughness exceeding that of spider silk, proteins and therapeutic biomolecules with exceptional properties have been developed using transgenic technology. The transgenic modifications have been done primarily by modifying the silk sericin and fibroin genes and also the silk producing glands. Although the genetic modifications were typically performed using the sericin 1 and other genes, newer techniques such as CRISPR/Cas9 have enabled successful modifications of both the fibroin H-chain and L-chain. Such modifications have led to the production of therapeutic proteins and other biomolecules in reasonable quantities at affordable costs for tissue engineering and other medical applications. Transgenically modified silkworms also have distinct and long-lasting fluorescence useful for bioimaging applications. This review presents an overview of the transgenic techniques for modifications of B. mori silkworms and the properties obtained due to such modifications with particular focus on production of growth factors, fluorescent proteins, and high performance protein fibers.
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Bombyx , Fibroínas , Animales , Bombyx/genética , Bombyx/metabolismo , Fibroínas/genética , Animales Modificados Genéticamente/genética , Seda/genética , Seda/metabolismo , FluorescenciaRESUMEN
Due to the lack of sufficient elasticity and strain sensing capability, protein-based ultrafine fibrous tissue engineering scaffolds, though favorable for skin repair, can hardly fulfill on-spot wound monitoring during healing. Herein, we designed highly elastic corn protein ultrafine fibrous smart scaffolds with a three-layer structure for motion tracking at an unpackaged state. The densely cross-linked protein networks were efficiently established by introducing a highly reactive epoxy and provided the fiber substrates with wide-range stretchability (360% stretching range) and ultrahigh elasticity (99.91% recovery rate) at a wet state. With the assistance of the polydopamine bonding layer, a silver conductive sensing layer was built on the protein fibers and endowed the scaffolds with wide strain sensing range (264%), high sensitivity (gauge factor up to 210.55), short response time (<70 ms), reliable cycling stability, and long-lasting duration (up to 30 days). The unpackaged smart scaffolds could not only support cell growth and accelerate wound closure but also track motions on skin and in vivo and trigger alarms once excessive wound deformations occurred. These features not only confirmed the great potential of these smart scaffolds for applications in tissue reconstruction and wound monitoring but also proved the possibility of employing various plant protein ultrafine fibers as flexible bioelectronics.
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Cicatrización de Heridas , Zea mays , Piel , Proliferación Celular , Andamios del Tejido/químicaRESUMEN
Additives provide substantial improvement in the properties of composites. Although bio-based composites are preferred over synthetic polymer and metal-based composites, they do not have the requisite properties to meet specific needs. Hence, organic, inorganic and metallic additives are included to improve the properties of bio-based composites. Coal is a readily available resource with high thermal insulation, flame resistance and other properties. This work demonstrates the addition of 20-30% natural sub-bituminous coal as filler for coir-reinforced polypropylene (PP) composites and exhibits an increased tensile strength by 66% and flexural strength by 55% compared to the composites without any filler. Such composites are intended for insulation applications and as a replacement for gypsum-based false ceiling tiles. Various ratios of coal samples were included in the composites and their effect on mechanical, acoustic, thermal insulation, flame and water resistance have been determined. A substantial improvement in both flexural and tensile properties has been observed due to the addition of coal. However, a marginal improvement has been observed in both thermal conductivity (0.65 W/mK) and flame resistance values due to the presence of coal. Adding coal increases the intensity of noise absorption, particularly at a higher frequency, whereas water sorption of the composites tends to decrease with an increase in the coal content. The addition of coal improves and adds unique properties to composites, allowing coir-coal-PP composites to outperform commercially available gypsum-based insulation panels.
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Retardadores de Llama , Polipropilenos , Sulfato de Calcio , Carbón Mineral , AguaRESUMEN
We synthesized an MFeCoB0.4CNx% (MOF-Fe/Co nanosheets/boron-doped g-C3N4) composite catalyst for enhancing the concurrent photocatalytic-persulfate activation (CPPA) system and achieved efficient degradation of antibiotics. The role of MOF-Fe/Co is to activate persulfate, while boron-doped g-C3N4 can generate photogenerated electrons for the reduction of Co3+/Fe3+ to enhance the regeneration of the active center. The rate constant for Tetracycline degradation by the CPPA system was 4.74 and 7.54 times higher than the photocatalytic and persulfate-activated systems, respectively. This composite was shown to be practical and economically viable for antibiotic degradation. The degradation behavior was explored based on experiments, and molecular orbitals and Fukui functions were obtained by density functional theory calculations. Mechanisms were investigated using reactive oxygen species trapping studies and electron spin resonance, and the process was explained in terms of the charge population and electron density difference of MOF-Fe/Co nanosheets. The CPPA system is an ecologically benign technology for removing antibiotic-related risks to the environment and human health.
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Antibacterianos , Boro , Humanos , Luz , Catálisis , TetraciclinaRESUMEN
Engineering photo-plasmonic platforms with heterometallic nanohybrids are of paramount significance for realizing augmented sensitivity in fluorescence-based analytical detection. Although myriad nanomaterials with versatile functionalities have been explored in this regard in the surface plasmon-coupled emission (SPCE) interface, light harvesting using nano-antennas synthesized via sustainable bio-inspired routes still remains a high priority in current research. Our study provides a rational design for in situ fabrication of nanoparticles of silver, gold, and their plasmonic hybrids using biocompatible, non-hazardous sericin protein (obtained Bombyx mori) as the reducing and capping agent. The one-pot, user-eco-friendly technology demonstrated here utilizes UV irradiation to promote the photo-induced electron transfer mechanism, thereby yielding nanomaterials of tunable optoelectronic functionalities. The resulting homometallic and heterometallic nanohybrids with robust localized surface plasmon resonances (LSPR) showed strong light-confining attributes when interfaced with the propagating surface plasmon polaritons (SPPs) of the SPCE platform, thereby yielding tunable, highly directional, polarized, and amplified fluorescence emission. The experimentally obtained emission profiles displayed an excellent correlation with the theoretically obtained dispersion diagrams validating the spectro-plasmonic results. The abundant hotspots from AgAu nanocubes presented in excess of 1300-fold dequenched fluorescence enhancement and were utilized for cost-effective and real-time mobile phone-based sensing of biologically relevant mefenamic acid at an attomolar limit of detection. We believe that this superior biosensing performance accomplished using the frugal bioinspired nano-engineering at hybrid interfaces would open new doors for developing nanofabrication protocols with the quintessential awareness of the principles of green nanotechnology, consequently eliminating hazardous chemicals and solvents in the development of point-of-care diagnostic tools.
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Teléfono Celular , Sericinas , Oro , Sustancias Peligrosas , Ácido Mefenámico , Plata , Solventes , Resonancia por Plasmón de Superficie/métodosRESUMEN
OBJECTIVE: To explore the effects of pH on properties of polyvinyl alcohol (PVA)-ionic hydrogels containing wound healing promoters. METHOD: PVA was combined with a natural wound healing promoter (silk sericin (SS)), and an anionic agent (eosin (ES)) or cationic agent (methylene blue (MB)), and made into hydrogels. Properties of the hydrogels and behaviour at different pHs were investigated. RESULTS: The density and gel fraction of PVA/SS-ES hydrogel and PVA/SS-MB hydrogel were considerably lower compared with hydrogel without SS. The swelling ratio and degradation of the hydrogels increased with increasing SS concentration in all pH solutions. The influence of SS in interrupting long-chain PVA molecules was confirmed based on changes in Fourier-transform infrared spectroscopy (FTIR). The SS released from the gels was found to interact with the ionic agent and influenced the release profile of the ionic agent. Surprisingly, the anionic agent in PVA/SS-ES hydrogel showed 70% release in high pH solution whereas the cationic agent in PVA/SS-MB hydrogel showed 86% release in low pH solution. Moreover, the active agent could accumulate on the skin layer and had a positive effect on a specific wound area. CONCLUSION: Based on the results obtained in this study, it is suggested to use anionic hydrogels containing wound healing promoter for wounds at high pH and cationic hydrogels containing wound healing promoter for wounds with low pH. Ability to improve wound healing using a natural healing agent combined with ionic agents and controlling the pH of hydrogels will help in developing quick and low-cost treatment for wounds.
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Alcohol Polivinílico , Cicatrización de Heridas , Humanos , Hidrogeles/farmacología , Piel/lesionesRESUMEN
BACKGROUND: Radiotherapy is a valuable treatment in the management algorithm of pituitary adenomas and craniopharyngiomas. However, the risk of second brain tumour following radiotherapy is a major concern. We assessed this risk using non-irradiated patients with the same primary pathology and imaging surveillance as controls. METHODS: In this multicentre, retrospective cohort study, 4292 patients with pituitary adenoma or craniopharyngioma were identified from departmental registries at six adult endocrine centres (Birmingham, Oxford, Leeds, Leicester, and Bristol, UK and Ferrara, Italy). Patients with insufficient clinical data, known genetic predisposition to or history of brain tumour before study entry (n=532), and recipients of proton beam or stereotactic radiotherapy (n=81) were excluded. Data were analysed for 996 patients exposed to 2-dimensional radiotherapy, 3-dimensional conformal radiotherapy, or intensity-modulated radiotherapy, and compared with 2683 controls. FINDINGS: Over 45 246 patient-years, second brain tumours were reported in 61 patients (seven malignant [five radiotherapy, two controls], 54 benign [25 radiotherapy, 29 controls]). Radiotherapy exposure and older age at pituitary tumour detection were associated with increased risk of second brain tumour. Rate ratio for irradiated patients was 2·18 (95% CI 1·31-3·62, p<0·0001). Cumulative probability of second brain tumour was 4% for the irradiated and 2·1% for the controls at 20 years. INTERPRETATION: Irradiated adults with pituitary adenoma or craniopharyngioma are at increased risk of second brain tumours, although this risk is considerably lower than previously reported in studies using general population controls with no imaging surveillance. Our data clarify an important clinical question and guide clinicians when counselling patients with pituitary adenoma or craniopharyngioma on the risks and benefits of radiotherapy. FUNDING: Pfizer.
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Adenoma , Neoplasias Encefálicas , Craneofaringioma , Neoplasias Hipofisarias , Adenoma/diagnóstico por imagen , Adenoma/epidemiología , Adenoma/radioterapia , Adulto , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/epidemiología , Neoplasias Encefálicas/radioterapia , Estudios de Cohortes , Craneofaringioma/complicaciones , Craneofaringioma/diagnóstico por imagen , Craneofaringioma/radioterapia , Humanos , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/radioterapia , Estudios RetrospectivosRESUMEN
OBJECTIVE: To investigate the long-term outcomes and prognosis of thyrotoxicosis in a large number of patients in a single UK county (Leicestershire). DESIGN: Retrospective cohort analysis of 56,741 thyroid function test (TFT) results, treatment modalities and outcomes in a well-established virtual thyrotoxicosis clinic database. PATIENTS: One thousand four hundred and eighty-nine patients were included with a median length of follow-up of 10.9 years. The aetiology of thyrotoxicosis was autoimmune (85.9%), nodular (9.1%) and mixed (5.0%). Treatment modalities included antithyroid drugs (ATDs), radioiodine (RAI; 555 MBq fixed dose) and thyroidectomy. METHODS: We analysed both individual TFTs and groups of sequential TFTs on or after the same thyroid treatment(s), which we describe as 'phase of thyroid care' (POTC). Patients studied entered the virtual clinic between 1 January 1995 and 1 January 2010; we exported data on every TFT sample up to April 2020. RESULTS: ATD had been used in 99.2% (median 2, maximum seven courses) with long-term ATD (>2 years) in 48%. RAI and thyroidectomy were used more commonly with nodular and mixed aetiology. Overall, T4 was more often controlled than thyroid-stimulating hormone (TSH), and at the latest follow-up, T4 was normal in >96%, TSH in >79% and both in >76% of different aetiologies. The mean percentage control of T4 was 85% and TSH 50%; in long-term ATD courses, this improved to 89% and 62%, respectively. In the latest POTC, control of T4 and TSH was best in cases off treatment (95%/87%) and on T4 without ablative therapy (94%/72%), but was broadly similar in patients on long-term ATD (90%/68%), after RAI (92%/60%) or after thyroidectomy (91%/58%). After the first course of ATD, remission or hypothyroidism was seen in 47.3% autoimmune, 20.9% nodular and 32.5% mixed, with 90% relapses seen within 4 years. Relapse was more common in patients with ophthalmopathy, but there was no difference between the sexes. CONCLUSIONS: Thyrotoxicosis can be well controlled with minimal specialist clinic attendance using a software-supported virtual shared-care scheme. Long-term ATD appears to be a valid patient choice achieving TFT control comparable to that seen after RAI or surgery. In patients with autoimmune disease, relapse is more common in patients with ophthalmopathy, and hypothyroidism is common after RAI. In nodular disease, we found that spontaneous remission may occur.
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Enfermedad de Graves , Hipotiroidismo , Tirotoxicosis , Antitiroideos/efectos adversos , Enfermedad de Graves/tratamiento farmacológico , Humanos , Hipotiroidismo/tratamiento farmacológico , Radioisótopos de Yodo/uso terapéutico , Recurrencia , Estudios Retrospectivos , Tirotoxicosis/tratamiento farmacológico , Tirotropina/uso terapéutico , Resultado del TratamientoRESUMEN
Hydroxyapatite (HA or HAp) is one of the most preferred biomaterials, specifically for bone tissue engineering. HAp is available naturally and is also chemically synthesized. The properties, shape, size and crystalline structure and applications of HAp vary widely depending on the source and extraction methods used. In addition to conventional chemical approaches such as precipitation or sol-gel techniques, newer methods such as microwave synthesis and atomic-layer deposition provide an opportunity to generate HAp with desirable structure and properties. Various methods used for the synthesis of HAp have their own pros and cons. Hence, it is essential to understand the role of specific methods and conditions on the properties and structure of HAps in order to obtain HAp with properties suitable for specific applications. In addition to pure HAp, substantial efforts have been made to dope HAp with various minerals or bioentities to enhance their suitability for medical, environmental remediation and other approaches. In this review, we provide an overview of the various chemical methods used to produce HAp, properties of the HAp produced and its potential applications. Particular focus of this paper is on the co-relation between properties and processes used to synthesis HAp. This review will enable readers to quickly understand the importance of synthesis methods and conditions on the properties of HAp and choose appropriate means to generate HAp with desired properties for specific applications.
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Durapatita , Ingeniería de Tejidos , Materiales Biocompatibles , Huesos , MicroondasRESUMEN
Finding a simple and eco-friendly production technique that matches to the natural agent and results in a truly valuable natural scaffold production is still limited amongst the intensively competitive natural scaffold development. Therefore, the purpose of this study was to develop natural scaffolds that were environmentally friendly, low cost, and easily produced, using natural agents and a physical crosslinking technique. These scaffolds were prepared from agarose and sericin using the freeze-drying method (D) or freeze-thawing together with the freeze-drying method (TD). Moreover, plasticizers were added into the scaffold to improve their properties. Their physical, mechanical, and biological properties were investigated. The results showed that scaffolds that were prepared using the TD method had stronger bonding between sericin and other compounds, leading to a low swelling ratio and low protein release of the scaffolds. This property may be applied in the development of further material as a controlled drug release scaffold. Adding plasticizers, especially glycerin, into the scaffolds significantly increased elongation properties, leading to an increase in elasticity of the scaffold. Moreover, all scaffolds could activate cell migration, which had an advantage on wound healing acceleration. Accordingly, this study was successful in developing natural scaffolds using natural agents and simple and green crosslinking methods.
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Nanoparticles from plant proteins are preferred over carbohydrates and synthetic polymeric-based materials for food, medical and other applications. In addition to their large availability and relatively low cost, plant proteins offer higher possibilities for surface modifications and functionalizing various biomolecules for specific applications. Plant proteins also avoid the immunogenic responses associated with the use of animal proteins. However, the sources of plant proteins are very diverse, and proteins from each source have distinct structures, properties and processing requirements. While proteins from corn (zein) and wheat (gliadin) are soluble in aqueous ethanol, most other plant proteins are insoluble in aqueous conditions. Apart from zein and gliadin nanoparticles (which are relatively easy to prepare), soy proteins, wheat glutenin and proteins from several legumes have been made into nanoparticles. The extraction of soluble proteins, hydrolyzing with alkali and acids, conjugation with other biopolymers, and newer techniques such as microfluidization and electrospraying have been adopted to develop plant protein nanoparticles. Solid, hollow, and core-shell nanoparticles with varying sizes and physical and chemical properties have been developed. Most plant protein nanoparticles have been used as carriers for drugs and as biomolecules for controlled release applications and for stabilizing food emulsions. This review provides an overview of the approaches used to prepare nanoparticles from plant proteins, and their properties and potential applications. The review's specific focus is on the preparation methods and applications, rather than the properties of the proteins, which have been reported in detail in other publications.
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Silk has remained the most preferred protein fiber since its discovery in 3000 BC. However, the cost, availability, and resources required to rear the silkworms and process silk are imposing considerable constraints on the future of silk. It is often unrealized that apart from the fibers, production and processing of silk are a source for a diverse range of sustainable, biodegradable, and biocompatible polymers. Hence, delineating itself from being the primary source of protein fibers for millenniums, the silk industry worldwide is transitioning into a biobased industry and as a source for pharmaceuticals, biomaterials, cosmetics, food, and energy. Toward this, byproducts (BPs) and co-products (CPs) that are inevitably generated are now being considered to be of immense economic value and could be up to 10 times more valuable than the silk fibers. Here, we elucidate the properties and potential applications of silk BPs and CPs to present the true potential of silkworms and to promote the establishment of silkworm-based bioeconomy and biorefineries.