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To enrich the properties of polylactic acid (PLA)-based composite films and improve the base degradability, in this study, a certain amount of poly(propylene carbonate) (PPC) was added to PLA-based composite films, and PLA/PPC-based composite films were prepared by melt blending and hot-press molding. The effects of the introduction of PPC on the composite films were analyzed through in-depth studies on mechanical properties, water vapor and oxygen transmission rates, thermal analysis, compost degradability, and bacterial inhibition properties of the composite films. When the introduction ratio coefficient of PPC was 30%, the tensile strength of the composite film increased by 19.68%, the water vapor transmission coefficient decreased by 14.43%, and the oxygen transmission coefficient decreased by 18.31% compared to that of the composite film without PPC, the cold crystallization temperature of the composite film increased gradually from 96.9 °C to 104.8 °C, and PPC improved the crystallization ability of composite film. The degradation rate of the composite film with PPC increased significantly compared to the previous one, and the degradation rate increased with the increase in the PPC content. The degradation rate was 49.85% and 46.22% faster on average than that of the composite film without PPC when the degradation was carried out over 40 and 80 days; the composite film had certain inhibition, and the maximum diameter of the inhibition circle was 2.42 cm. This study provides a strategy for the development of PLA-based biodegradable laminates, which can promote the application of PLA-based laminates in food packaging.
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Poliésteres , Propano/análogos & derivados , Resistência à Tração , Poliésteres/química , Polipropilenos/química , Embalagem de Alimentos/métodos , Vapor , Polímeros/química , Antibacterianos/química , Antibacterianos/farmacologia , TemperaturaRESUMO
Acute pancreatitis (AP) is a common and potentially life-threatening inflammatory disease of the pancreas. Reactive oxygen species (ROS) play a key role in the occurrence and development of AP. With increasing ROS levels, the degree of oxidative stress and the severity of AP increase. However, diagnosing AP still has many drawbacks, including difficulties with early diagnosis and undesirable sensitivity and accuracy. Herein, we synthesized a semiconducting polymer nanoplatform (SPN) that can emit ROS-correlated chemiluminescence (CL) signals. The CL intensity increased in solution after optimization of the SPN. The biosafety of the SPN was verified in vitro and in vivo. The mechanism and sensitivity of the SPN for AP early diagnosis and severity assessment were evaluated in three groups of mice using CL intensity, serum marker evaluations and hematoxylin and eosin staining assessments. The synthetic SPN can be sensitively combined with different concentrations of ROS to produce different degrees of high-intensity CL in vitro and in vivo. Notably, the SPN shows an excellent correlation between CL intensity and AP severity. This nanoplatform represents a superior method to assess the severity of AP accurately and sensitively according to ROS related chemiluminescence signals. This research overcomes the shortcomings of AP diagnosis in clinical practice and provides a novel method for the clinical diagnosis of pancreatitis in the future.
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Pancreatite , Camundongos , Animais , Pancreatite/diagnóstico , Espécies Reativas de Oxigênio , Polímeros , Doença Aguda , Diagnóstico PrecoceRESUMO
Acute body mass loss before competitions in combat sports usually leads to loss in fat-free mass. Beta-hydroxy-beta-methylbutyrate (HMB) has been shown to increase skeletal muscle mass and muscle strength in various muscle wasting conditions. This study investigated the effect of HMB supplementation on body composition and sport-specific performance in well-trained boxers consuming a hypocaloric diet. Twelve male college boxers were divided into the HMB and placebo (PLA) groups using a body weight-matched single-blind parallel design. The study comprised a 6-day weight loss period (days 1-6), followed by a 3-day competition period (days 7-9). The participants in both the groups consumed 16 kcal/kg/day, including 1.6-1.7 g/kg of carbohydrates, 1.2-1.3 g/kg of protein, and 0.45-0.5 g/kg of fat during the 9-day period. The HMB group consumed 3 g/day HMB. Body composition measurement, isometric mid-thigh pull (IMTP), and a simulated boxing match were performed at baseline and on days 7, 8, and 9. Fasting blood samples were collected on the day before day 1 and on days 7, 8, and 9. Body mass was significantly decreased after the 6-day weight loss period (HMB group: baseline: 69.4 ± 11.2 kg, day 7: 67.1 ± 11.2 kg; PLA group: baseline: 68.6 ± 12.1 kg, day 7: 65.7 ± 11.5 kg, P < 0.05) while it was unchanged on the 3-day competition period in both the groups. Fat-free mass in the HMB group was maintained throughout the 9-day period (baseline: 56.7 ± 9.3 kg, day 7: 56.3 ± 8.7 kg, day 9: 55.8 ± 9.5 kg) whereas it significantly decreased on days 7 and 9 compared to the baseline in the PLA group (baseline: 55.2 ± 6.4 kg, day 7: 54.1 ± 6.6 kg, day 9: 54.0 ± 6.6 kg, P < 0.05). In the PLA group, the average and maximal heart rates in round 1 and the average heart rate in round 2 on days 8 and 9 were significantly lower than those at baseline, while these parameters were unchanged in the HMB group. The maximal force and the rate of force development in the IMTP remained unchanged among the different timepoints in both the groups. The blood biochemical parameters were similar at any timepoint between the PLA and HMB groups. HMB supplementation during acute weight loss may preserve fat-free mass and maintain heart rate response in subsequent simulated matches in well-trained boxers. In addition, HMB supplementation had a nonsignificant effect on glucose, fat, and protein metabolism during energy restriction.
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Dieta Redutora , Suplementos Nutricionais , Humanos , Masculino , Composição Corporal , Músculo Esquelético/fisiologia , Obesidade , Poliésteres/farmacologia , Método Simples-Cego , Redução de PesoRESUMO
Filaments driven by bound motor proteins and chains of self-propelled colloidal particles are a typical example of active polymers (APs). Due to deformability, APs exhibit very rich dynamic behaviors and collective assembling structures. Here, we are concerned with a basic question: how APs behave near a single obstacle? We find that, in the presence of a big single obstacle, the assembly of APs becomes a two-state system, i.e. APs either gather nearly completely together into a giant jammed aggregate (GJA) on the surface of the obstacle or distribute freely in space. No partial aggregation is observed. Such a complete aggregation/collection is unexpected since it happens on a smooth convex surface instead of, e.g., a concave wedge. We find that the formation of a GJA experiences a process of nucleation and the curves of the transition between the GJA and the non-aggregate state form hysteresis-like loops. Statistical analysis of massive data on the growing time, chirality and angular velocity of both the GJAs and the corresponding nuclei shows the strong random nature of the phenomenon. Our results provide new insights into the behavior of APs in contact with porous media and also a reference for the design and application of polymeric active materials.
Assuntos
PolímerosRESUMO
Background: Percutaneous kyphoplasty (PKP) is an effective minimally invasive technique for the treatment of osteoporotic vertebral fracture (OVF) in recent years. This study focuses on the analysis of PKP surgery and anesthesia in osteoporotic vertebral facture patients over 90 years old with the concept of "enhanced recovery after surgery." Methods: This study reviewed 239 patients who were diagnosed with OVF retrospectively between October 2015 and June 2019. According to the method of anesthesia, these patients were divided into Group A (n = 125) and Group B (n = 114). According to the pedicle puncture approach, these patients were divided into Group C (n = 102) and Group D (n = 137). The anterior vertebral height (AVH) and local kyphosis angle (LKA) were used to evaluate the degree of vertebral damage and restoration. The visual analogue scale (VAS) and the Oswestry Disability Index (ODI) scores were used for assessing functional outcomes. Some parameters were used to assess the perioperative conditions such as operation time, amount of bone cement perfusion, intraoperative fluoroscopy times, anesthesia recovery time, time out of the bed, hospital stay, hospitalization cost, and complications. Results: The visual analogue scale (VAS), Oswestry Disability Index (ODI), anterior vertebral height (AVH), and local kyphosis angle (LKA) 1 day, 1 year after surgery, and at the last follow-up all showed significant improvement (P < 0.05) in comparison with those before surgery both in Groups A and B and Groups C and D. The ODI 1 day after surgery was significantly better in Group B than Group A (P < 0.05). Compared with Group B, Group A required longer time of anesthesia, operation time, anesthesia recovery time, time to get out of bed, and length of hospital stay and more hospitalization costs (P < 0.05). Group D required longer operation time, longer time to get out of bed, more bone cement volume, fluoroscopy time, and more operation hospitalization costs compared with Group C (P < 0.05). Conclusion: We recommend unilateral puncture under local anesthesia for OVF in the patients aged over 90 from the perspective of rapid recovery.
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Anestesia , Fraturas por Compressão , Cifoplastia , Cifose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Idoso , Idoso de 80 Anos ou mais , Cimentos Ósseos/uso terapêutico , Fraturas por Compressão/cirurgia , Humanos , Cifoplastia/métodos , Cifose/cirurgia , Fraturas por Osteoporose/cirurgia , Punções , Estudos Retrospectivos , Fraturas da Coluna Vertebral/cirurgiaRESUMO
BACKGROUND: Different substances are combined to compensate for each other's drawbacks and create an appropriate biomaterial. A novel Polyvinyl alcohol (PVA)/chitosan (CS) porous hydrogel was designed and applied to the treatment of osteochondral defects. METHODS: Hydrogels of various PVA/CS ratios were tested for physiochemical and mechanical properties in addition to cytotoxicity and biocompatibility. The hydrogels with the best PVA/CS ratio were used in the animal study. Osteochondral defects were created at the articular cartilage of 18 rabbits. They were assigned to different groups randomly (n = 6 per group): the osteochondral defect only group (control group), the osteochondral defect treated with hydrogel group (HG group), and the osteochondral defect treated with hydrogel loaded with bone marrow mesenchymal stem cells (BMSCs) group (HG-BMSCs group). The cartilage was collected for macro-observation and histological evaluation at 12 weeks after surgery. RESULTS: The Hydrogel with PVA/CS ratio of 6:4 exhibited the best mechanical properties; it also showed stable physical and chemical properties with porosity and over 90% water content. Furthermore, it demonstrated no cytotoxicity and was able to promote cell proliferation. The HG-BMSCs group achieved the best cartilage healing. CONCLUSIONS: The novel PVA/CS porous composite hydrogel could be a good candidate for a tissue engineering material in cartilage repair.
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Materiais Biocompatíveis/efeitos adversos , Doenças das Cartilagens/terapia , Hidrogéis/efeitos adversos , Transplante de Células-Tronco Mesenquimais , Alicerces Teciduais/efeitos adversos , Animais , Doenças das Cartilagens/patologia , Cartilagem Articular/citologia , Cartilagem Articular/lesões , Cartilagem Articular/fisiologia , Proliferação de Células/efeitos dos fármacos , Quitosana/administração & dosagem , Quitosana/efeitos adversos , Condrogênese/efeitos dos fármacos , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Modelos Animais de Doenças , Humanos , Hidrogéis/administração & dosagem , Masculino , Teste de Materiais , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Álcool de Polivinil/administração & dosagem , Álcool de Polivinil/efeitos adversos , Porosidade , Coelhos , Regeneração/efeitos dos fármacos , Testes de Toxicidade , Resultado do Tratamento , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologiaRESUMO
Microplastics are increasingly prevalent in the environment, and their ability to adsorb various organic additives, posing harm to organisms, has attracted growing attention. Currently, there are no effective methods to age microplastics, and there is limited discussion on the subsequent treatment of aged microplastics. This study focuses on micro polyethylene (PE) and employs electron beam technology for aging treatment, investigating the adsorption and leaching behavior between PE and dibutyl phthalate (DBP) before and after aging. Experimental results indicate that with increasing doses of electron beam irradiation, the surface microstructure of PE worsens, inducing the generation of oxygen-containing functional groups on the surface of polyethylene. Comparative evaluations between electron beam aging and existing methods show that electron beam technology surpasses existing aging methods, achieving a level of aging exceeding 0.7 within an extremely short period of 1 min at doses exceeding 350 kGy. Adsorption experiments demonstrate that the adsorption between PE and DBP conforms to pseudo-second-order kinetics and the Freundlich model both before and after aging. The adsorption capacity of microplastics for DBP increases from 76.8 mg g-1 to 167.0 mg g-1 after treatment, exceeding that of conventional DBP adsorbents. Electron beam irradiation causes aging of microplastics mainly through the generation of ·OH, which lead to the formation of oxygen-containing functional groups on the microplastics' surface, thereby enhancing their adsorption capacity for DBP. This provides a new perspective for the degradation of aged microplastics and composite pollutants.
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Dibutilftalato , Microplásticos , Adsorção , Dibutilftalato/química , Microplásticos/química , Cinética , Polietileno/química , Elétrons , Poluentes Químicos da Água/químicaRESUMO
Nocardia is an anthropozoonotic bacteria that occurs widely in the natural environment. However, because it is a gram-positive aerobic opportunistic pathogen, it rarely occurs in patients with no prior history of immune function disease. Since the symptoms are nonspecific the diagnosis of Nocardia pneumonia is challenging. Previous studies have not reported that this anthropozoonotic bacteria colonizing the human body could cause severe pneumonia by gingival pain and pharyngeal discomfort. This case report describes a previously healthy 60-year-old female farmer who presented to the doctor with gingival pain and pharyngeal discomfort. She was treated with a dental cleaning and oral metronidazole. The patient rapidly progressed to breathing difficulties. Lung shadow was found by computerized tomography examination. The radiologist diagnosed pulmonary tuberculosis as image-based. Through laboratory examination and culture of pathogenic microorganisms in the sputum and blood of the patient, no obvious positive findings were found. The disease progressed rapidly to tracheal intubation ventilator assisted breathing. Subsequently, the patient underwent alveolar lavatory examination under endotracheal intubation fiberbronchoscopy, and the culture of alveolar lavage fluid indicated Nocardia. According to this result, the patient's disease was quickly controlled after selecting the targeted drug compound sulfamethoxazole and intravenous meropenem for treatment. In view of the reason for the high misdiagnosis rate due to the low positive rate of Nocardia culture in most cases, the clinical thinking of diagnosis and treatment from oral infection symptoms to fatal pneumonia reported in this case has certain clinical popularization and enlighten significance, not only improved the diagnosis and treatment of rare diseases, but also be reduced medical disputes.
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Patients with open abdominal (OA) wounds have a mortality risk of up to 30%, and the resulting disabilities would have profound effects on patients. Here, we present a novel double-sided adhesive tape developed for the management of OA wounds. The tape features an asymmetrical structure and employs an acellular dermal matrix (ADM) with asymmetric wettability as a scaffold. It is constructed by integrating a tissue-adhesive hydrogel composed of polydopamine (pDA), quaternary ammonium chitosan (QCS), and acrylic acid cross-linking onto the bottom side of the ADM. Following surface modification with pDA, the ADM would exhibit characteristics resistant to bacterial adhesion. Furthermore, the presence of a developed hydrogel ensures that the tape not only possesses tissue adhesiveness and noninvasive peelability but also effectively mitigates damage caused by oxidative stress. Besides, the ADM inherits the strength of the skin, imparting high burst pressure tolerance to the tape. Based on these remarkable attributes, we demonstrate that this double-sided (D-S) tape facilitates the repair of OA wounds, mitigates damage to exposed intestinal tubes, and reduces the risk of intestinal fistulae and complications. Additionally, the D-S tape is equally applicable to treating other abdominal injuries, such as gastric perforations. It effectively seals the perforation, promotes injury repair, and prevents the formation of postoperative adhesions. These notable features indicate that the presented double-sided tape holds significant potential value in the biomedical field.
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Traumatismos Abdominais , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Adesivos Teciduais/química , Adesivos Teciduais/farmacologia , Quitosana/química , Quitosana/farmacologia , Camundongos , Polímeros/química , Polímeros/farmacologia , Humanos , Indóis/química , Indóis/farmacologia , Cicatrização/efeitos dos fármacos , Pressão , Masculino , RatosRESUMO
The problems of step effects, supporting material waste, and conflict between flexibility and toughness for 3D printed intestinal fistula stents are not yet resolved. Herein, the fabrication of a support-free segmental stent with two types of thermoplastic polyurethane (TPU) using a homemade multi-axis and multi-material conformal printer guided with advanced whole model path planning is demonstrated. One type of TPU segment is soft to increase elasticity, and the other is used to achieve toughness. Owing to advancements in stent design and printing, the obtained stents present three unprecedented properties compared to previous three-axis printed stents: i) Overcoming step effects; ii) Presenting comparable axial flexibility to a stent made of a single soft TPU 87A material, thus increasing the feasibility of implantation; and iii) Showing equivalent radial toughness to a stent made of a single hard TPU 95A material. Hence, the stent can resist the intestinal contractive force and maintain intestinal continuity and patency. Through implanting such stents to the rabbit intestinal fistula models, therapeutic mechanisms of reducing fistula output and improving nutritional states and intestinal flora abundance are revealed. Overall, this study develops a creative and versatile method to improve the poor quality and mechanical properties of medical stents.
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Fístula Intestinal , Stents , Animais , Coelhos , Poliuretanos , Fenômenos Mecânicos , Impressão TridimensionalRESUMO
Microcystin-LR (MC-LR), an inert electrochemical species, is difficult to be detected by a simple and direct electrochemical method. In the present work, a novel photoelectrochemical sensor is developed on highly ordered and vertically aligned TiO(2) nanotubes (TiO(2) NTs) with convenient surface modification of molecularly imprinted polymer (MIP) (denoted as MIP@TiO(2) NTs) for highly sensitive and selective determination of MC-LR in solutions. Molecularly imprinted polypyrrole (PPy) of MC-LR is chosen as the recognition element. The designed MIP@TiO(2) NTs photoelectrochemical sensor presents excellent applicability in MC-LR determination, with linear range from 0.5 to 100 µg L(-1) and limit of detection of 0.1 µg L(-1). Moreover, the sensor exhibits outstanding selectivity while used in coexisting systems containing 2,4-dichorophenoxyacetic acid, atrazine, paraquat, or monosultap with high concentration, 100 times that of MC-LR. The sensor presents good photoelectric conversion efficiency and detection sensitivity, as well as broad linear detection range, mainly because of the high specific surface area and photoelectric activity of TiO(2) NTs and the π bond delocalized electron system of PPy that promotes the separation of electron-holes. The prominent selectivity is from the MIP by forming multiple hydrogen bonds between PPy and MC-LR. Mechanisms for photoelectrochemical analysis and selective recognition are also discussed.
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Toxinas Bacterianas/análise , Monitoramento Ambiental/métodos , Toxinas Marinhas/análise , Microcistinas/análise , Poluentes Químicos da Água/análise , Toxinas Bacterianas/química , Técnicas Eletroquímicas , Toxinas Marinhas/química , Microcistinas/química , Impressão Molecular , Nanoestruturas/química , Processos Fotoquímicos , Polímeros/química , Pirróis/química , Titânio/química , Poluentes Químicos da Água/químicaRESUMO
The aim of this study was to investigate the cumulative effects of intensive resistance training on salivary immunoglobulin A (SIgA) and cortisol responses in elite male weightlifters. Eleven elite male Taiwanese weightlifters were trained through 3 training stages before a national weightlifting competition, and this was followed by a 2-week recovery stage. Resting saliva samples were collected once in each of the 4 stages. Salivary concentrations of total protein (TP), SIgA, lactoferrin, and cortisol were measured. The results showed that (a) salivary TP concentrations were not significantly affected; (b) resting levels of SIgA, the ratio of SIgA to TP (SIgA/TP), cortisol, and the ratio of cortisol to TP (cortisol/TP) were significantly higher in the training stages than in the recovery stage; (c) a positive correlation was revealed between the ratios of SIgA/TP and cortisol/TP; and (d) the resting salivary lactoferrin concentrations and the ratio of lactoferrin to TP (lactoferrin/TP) were significantly lower in stage 1 than in the recovery stage. The findings in this study suggest that prolonged, intensive resistance training exerts cumulative effects on SIgA and cortisol responses in elite weightlifters.
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Hidrocortisona/metabolismo , Imunoglobulina A/metabolismo , Treinamento Resistido , Saliva/química , Levantamento de Peso/fisiologia , Adulto , Humanos , Hidrocortisona/análise , Imunoglobulina A/análise , Lactoferrina/análise , Masculino , Proteínas e Peptídeos Salivares/análise , Adulto JovemRESUMO
Polylactic acid-based (PLA) composites are widely used in biomedicine, electrical components, food packaging and other fields, but their unsatisfactory mechanical properties such as high brittleness and poor toughness, cause problems in functional applications. This work developed a green and environmentally friendly strategy to improve PLA mechanical properties. Flexible polybutylene succinate (PBS) and alkaline hydrogen peroxide (AHP) treated straw fibers (SF) synergistically modified PLA. AHP is decomposed into a large amount of HOO-, which oxidizes the hydroxyl groups in SF to carboxyl groups to obtain oxidized straw fiber (OSF), which reacts with PLA in the molten state to form new ester bonds. The tensile strength of the OSF/PLA composite is 41.78 MPa, 38 % higher than the SF/PLA composite. The impact toughness of OSF/PBS/PLA composite is 14.47 KJ/m2 increased by 54 % after the adding PBS, while the tensile strength was also better than the control group. The synergistic action of PLA and PBS in OSF is attributed to the formation of new chemical bonds, efficient crystallization, and compatible interface. This study provides a new strategy to produce fiber-reinforced PLA composites with good toughness. It takes positive significance for developing degradable plastics with good performance and controllable cost.
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Elastômeros , Poliésteres , Poliésteres/química , Polímeros/químicaRESUMO
As a consequence of the current trend of performing minimally invasive surgery, the use of injectable fillers has progressively increased in aesthetic surgery. Vascular complications resulting due to the filling of hyaluronic acid (HA) in the chin have been previously reported. However, clinical evidence regarding the results of treatment of lingual artery occlusion with super-selective intra-arterial dissolution is lacking. Herein, we reported a case of lingual artery occlusion resulting due to HA filling for which tongue arteriography and catheter-directed dissolution were implemented via femoral artery intubation for the first time in the literature. The aim of this paper was to discuss the rare complications arising due to chin augmentation and their treatment to provide a deeper understanding of the use and side effects of HA in this procedure.
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Arteriopatias Oclusivas , Técnicas Cosméticas , Preenchedores Dérmicos , Arteriopatias Oclusivas/induzido quimicamente , Arteriopatias Oclusivas/terapia , Artérias , Queixo , Técnicas Cosméticas/efeitos adversos , Preenchedores Dérmicos/efeitos adversos , Humanos , Ácido Hialurônico/efeitos adversos , Solubilidade , LínguaRESUMO
Endothelialization of vascular implants plays a vital role in maintaining the long-term vascular patency. In situ endothelialization and re-endothelialization is generally achieved by selectively promoting endothelial cell (EC) adhesion and, meanwhile, suppressing smooth muscle cell (SMC) adhesion. Currently, such EC versus SMC selectivity is achieved and extensively used in vascular-related biomaterials utilizing extracellular-matrix-derived EC-selective peptides, dominantly REDV and YIGSR. Nevertheless, the application of EC-selective peptides is limited due to their easy proteolysis, time-consuming synthesis, and expensiveness. To address these limitations, a polymeric strategy in designing and finding EC-selective biomaterials using amphiphilic ß-peptide polymers by tuning serum protein adsorption is reported. The optimal ß-peptide polymer displays EC versus SMC selectivity even superior to EC-selective REDV peptide regarding cell adhesion, proliferation, and migration of ECs versus SMCs. Study of the mechanism indicates that surface adsorption of bovine serum albumin, an abundant and anti-adhesive serum protein, plays a critical role in the ECs versus SMCs selectivity of ß-peptide polymer. In addition, surface modification of the optimal ß-peptide polymer effectively promotes the endothelialization of vascular implants and inhibits intimal hyperplasia. This study provides an alternative strategy in designing and finding EC-selective biomaterials, implying great potential in the vascular-related biomaterial study and application.
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Peptídeos , Soroalbumina Bovina , Polímeros , Adesão Celular , Materiais Biocompatíveis/farmacologia , Matriz Extracelular , Poder PsicológicoRESUMO
The high mortality rate of invasive fungal infections and quick emergence of drug-resistant fungal pathogens urgently call for potent antifungal agents. Inspired by the cell penetrating peptide (CPP) octaarginine (R8), we elongated to 28 residues poly(d,l-homoarginine) to obtain potent toxicity against both fungi and mammalian cells. Further incorporation of glutamic acid residues shields positive charge density and introduces partial zwitterions in the obtained optimal peptide polymer that displays potent antifungal activity against drug-resistant fungi superior to antifungal drugs, excellent stability upon heating and UV exposure, negligible in vitro and in vivo toxicity, and strong therapeutic effects in treating invasive fungal infections. Moreover, the peptide polymer is insusceptible to antifungal resistance owing to the unique CPP-related antifungal mechanism of fungal membrane penetration followed by disruption of organelles within fungal cells. All these merits imply the effectiveness of our strategy to develop promising antifungal agents.
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Peptídeos Penetradores de Células , Infecções Fúngicas Invasivas , Animais , Antifúngicos/química , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Peptídeos Penetradores de Células/farmacologia , Farmacorresistência Fúngica , Fungos , Infecções Fúngicas Invasivas/tratamento farmacológico , Mamíferos , Polímeros/farmacologiaRESUMO
Growth factors (GFs) play important roles in biological system and are widely used in tissue regeneration. However, their application is greatly hindered by short in vivo lifetime of GFs. GFs are bound to fibronectin dynamically in the extracellular matrix, which inspired the authors to mimic the GF binding domain of fibronectin and design GF-binding amphiphilic copolymers bearing positive charges. The optimal amino acid polymer can bind to a variety of representative GFs, such as bone morphogenetic protein-2 (BMP-2) and TGF-ß1 from the transforming growth factor-ß superfamily, PDGF-AA and PDGF-BB from the platelet-derived growth factor family, FGF-10 and FGF-21 from the fibroblast growth factor family, epidermal growth factor from the EGF family and hepatocyte growth factor from the plasminogen-related growth factor family, with binding affinities up to the nanomolar level. 3D scaffolds immobilized with the optimal copolymer enable sustained release of loaded BMP-2 without burst release and significantly enhances the in vivo function of BMP-2 for bone formation. This strategy opens new avenues in designing GF-binding copolymers as synthetic mimics of fibronectin for diverse applications.
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Fibronectinas , Osteogênese , Becaplermina/metabolismo , Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , PolímerosRESUMO
OBJECTIVE: Patients with hypoparathyroidism always present with recurrent tetany caused by hypocalcemia. These patients are usually misdiagnosed with epilepsy and incorrectly treated with anti-epileptic drugs. This research analyzed clinical data about 22 patients with hypoparathyroidism misdiagnosed as epilepsy and summarized the clinical experience for reducing misdiagnosis and incorrect therapy about hypoparathyroidism. METHOD: Totally 160 patients with hypoparathyroidism, administrated to the First Medical Center of Chinese PLA General Hospital from January 1st, 2008, to July 1st, 2021, were enrolled in this report. Clinical data about 22 patients initially misdiagnosed with epilepsy were analyzed. RESULTS: Of the 160 cases with hypoparathyroidism, 22 patients (12 males and 10 females) were misdiagnosed with epilepsy in local hospitals. The misdiagnosis rate was 13.75% and the median duration of misdiagnosis was 8.0 (2.0, 14.8) years. The clinical manifestations of the 22 patients misdiagnosed as epilepsy included tetany 81.8% (18/22), disturbance of consciousness 27.3% (6/22), limb numbness 13.6% (3/22), limb weakness 27.3% (6/22), mental and behavioral abnormality 9.1% (2/22), and memory impairment 13.6% (3/22), etc. Electroencephalogram (EEG) was performed in 9 cases, which presented as slow wave and spike-slow complex wave in 3 cases, slowing down of θ and δ band background in 2 cases and normal EEG in 4 cases. Out of the 15 cases that underwent head computed tomography (CT) scan, in which 13 cases had intracranial calcification. Anti-epileptic drugs were used to treat 22 patients, of which 17 patients were treated with two kinds of drugs. With calcium and calcitriol supplement in all these 22 patients, the anti-epileptic drugs were gradually reduced and withdrawn in 17 cases. In the other 5 cases with secondary epilepsy, the type of anti-epileptic drugs was reduced to one and the clinical condition improved obviously. CONCLUSION: The clinical manifestations of hypoparathyroidism are complex and usually be misdiagnosed as primary epilepsy. Detection of serum calcium, phosphorus and parathyroid hormone is very important to avoid misdiagnosis and incorrect therapy about hypoparathyroidism.
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Epilepsia , Hipoparatireoidismo , Tetania , Calcitriol , Cálcio , Análise de Dados , Erros de Diagnóstico , Epilepsia/complicações , Epilepsia/diagnóstico , Epilepsia/tratamento farmacológico , Feminino , Humanos , Hipoparatireoidismo/diagnóstico , Hipoparatireoidismo/tratamento farmacológico , Masculino , Hormônio Paratireóideo , Fósforo , Poliésteres , Tetania/induzido quimicamente , Tetania/complicações , Tetania/tratamento farmacológicoRESUMO
To improve the performance of wheat straw/polylactic acid (WS/PLA) composites, four different silane coupling agents were used for constructing compatible interfaces and then examined by scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray diffractometry and thermogravimetric analysis. The blending and tensile strengths of silane-modified composites were effectively enhanced, with KH-570-modified composite exhibiting the best blending and tensile strengths. Water resistance analysis of silane-modified composites was reduced and contact angles larger, indicating that water resistance performance of this composite had been effectively improved. The KH-570-modified composite exhibited the best water resistance performance. Strain scanning showed that, in the linear viscoelastic region, the storage modulus (G') of modified composite was larger than that of unmodified composites. Frequency scanning showed that the G' and complex viscosity (η*) of modified composites were greater than those of unmodified composites. From strain analysis and frequency scanning, the modified performance of the silane agent was observed to effectively improve composite interfacial compatibility, with KH-570-modified composite exhibiting the best effect. XRD analysis showed that silane coupling agent modification improved the crystallinity of composites with the improvement of KH-570 the best. And the thermal stability of silane-modified composites was improved and the thermal stability of KH-570-modified composite the best.
Assuntos
Poliésteres/química , Silanos/química , Triticum/química , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Resistência à Tração , Termogravimetria , Água/química , Difração de Raios XRESUMO
Membrane property and feed characteristics play critical roles in membrane fouling. This paper aims to clarify the roles of membrane pore size (φ) and feed foulant concentration (Cb ) in ultrafiltration fouling induced by polysaccharides. The fouling behaviors were expounded by collision-attachment theory, where the rate of membrane fouling is mainly determined by collision frequency (JCb ) and attachment efficiency (γ). At the initial fouling stage, rapid flux decline was observed at large φ or high Cb due to the great JCb and/or γ. At the later fouling stage, there existed a nearly identical maximum stable flux attributing to the same JCb and γ, which was independent of φ and Cb . Moreover, the smaller φ can lead to less foulants passed through the membrane and thus more foulants attaching on the membrane, while the higher Cb can give rise to more foulants on both the membrane surface and in the permeate. The results presented in current study provide fundamental basis in understanding membrane fouling. PRACTITIONER POINTS: Collision-attachment theory was employed to expound the UF fouling behavior. Rapid flux decline occurred at large membrane pore size or high feed foulant concentration in the initial fouling stage. Membranes with different pore size or feed foulant concentration had an identical flux at the latter fouling stage. Lowering membrane pore size or increasing feed foulant concentration can lead to more foulants attaching on the membrane surface.