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1.
Sensors (Basel) ; 22(20)2022 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-36298329

RESUMEN

In order to improve the prediction accuracy regarding low compaction level of asphalt pavement, this paper carries out indoor tests to detect the voids and dielectric constants of AC-13, AC-16 and AC-25 asphalt mixtures, obtaining their relationship equations via linear fitting and determining the dielectric constant judgment threshold of low compaction level segregation risk points ε1. Based on the common mid-point method, three-dimensional ground-penetrating radar is used to obtain the dielectric constant of the physical engineering test section. The researcher can draw the distribution map of the low compaction level segregation risk area according to the judgment threshold ε1 of the rough segregation risk points; divide the connected risk areas; determine the regional convex hull; and calculate the regional indicators such as the regional area, the ratio of the convex risk points and the mean value of the regional dielectric constant. The response surface analysis method is used to acquire the model of risk area index and core void ratio. The model is employed to predict and verify the core void ratio in the risk area of the road section and verify the accuracy of the model. The results show that the error range between the predicted voids and the measured voids is -0.4%~+0.4%, and the mean absolute value of the error is 0.25%. Compared with the mean measured voids of 6.63%, the relative error is 3.77%, indicating that the model can accurately predict the regional low compaction level segregation degree.

2.
Sensors (Basel) ; 22(23)2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36502068

RESUMEN

Three-dimensional (3D) ground-penetrating radar is an effective method for detecting internal crack damage in pavement structures. Inefficient manual interpretation of radar images and high personnel requirements have substantially restrained the generalization of 3D ground-penetrating radar. An improved Crack Unet model based on the Unet semantic segmentation model is proposed herein for 3D ground-penetrating radar crack image processing. The experiment showed that the MPA, MioU, and accuracy of the model were improved, and it displayed better capacity in the radar image crack segmentation task than current mainstream algorithms do, such as deepLabv3, PSPNet, and Unet. In the test dataset without cracks, Crack Unet is on the same level as deepLabv3 and PSPNet, which can meet engineering requirements and display a significant improvement compared with Unet. According to the ablation experiment, the MPA and MioU of Unet configured with PMDA, MC-FS, and RS modules were larger than those of Unet configured with one or two modules. The PMDA module adopted by the Crack Unet model showed a higher MPA and MioU than the SE module and the CBAM module did, respectively. The results show that the Crack Unet model has a better segmentation ability than the current mainstream algorithms do in the task of the crack segmentation of radar images, and the performance of crack segmentation is significantly improved compared with the Unet model. The Crack Unet model has excellent engineering application value in the task of the crack segmentation of radar images.


Asunto(s)
Algoritmos , Radar , Reconocimiento en Psicología , Procesamiento de Imagen Asistido por Computador , Semántica
4.
World J Surg Oncol ; 12: 308, 2014 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-25305782

RESUMEN

The most common complications after thyroidectomy are injuries associated with the recurrent laryngeal nerve and parathyroid gland. Cervical esophagus perforation is an exceptionally rare complication after thyroidectomy; it can usually be resolved by conservative care. Cervical esophageal stenosis secondary to intraoperative esophageal injury during thyroidectomy is much rarer and has not been reported in the literature to date. We report a case of esophageal stenosis following thyroidectomy performed at a peripheral hospital. The patient initially underwent a thyroidectomy for papillary thyroid carcinoma involving the cervical esophagus; esophageal perforation was noted intraoperatively, and closed using three number 4 silk sutures. Cervical esophageal stenosis subsequently developed after conservative care. The patient was successfully treated with cervical esophagectomy and reconstruction using a tubed forearm free flap after a failed attempt at endoscopic recanalization. This case is discussed in conjunction with a review of the literature.


Asunto(s)
Carcinoma/cirugía , Perforación del Esófago/etiología , Estenosis Esofágica/etiología , Complicaciones Intraoperatorias/cirugía , Complicaciones Posoperatorias/etiología , Neoplasias de la Tiroides/cirugía , Tiroidectomía/efectos adversos , Anciano , Carcinoma Papilar , Perforación del Esófago/cirugía , Estenosis Esofágica/diagnóstico , Estenosis Esofágica/cirugía , Esofagectomía , Femenino , Humanos , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/cirugía , Procedimientos de Cirugía Plástica , Cáncer Papilar Tiroideo
5.
Carbohydr Polym ; 341: 122348, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38876718

RESUMEN

Antibiotic abuse is increasing the present rate of drug-resistant bacterial wound infections, producing a significant healthcare burden globally. Herein, we prepared a pH-responsive CMCS/PVP/TA (CPT) multifunctional hydrogel dressing by embedding the natural plant extract TA as a nonantibiotic and cross-linking agent in carboxymethyl chitosan (CMCS) and polyvinylpyrrolidone (PVP) to prompt wound healing. The CPT hydrogel demonstrated excellent self-healing, self-adaptive, and adhesion properties to match different wound requirements. Importantly, this hydrogel showed pH sensitivity and exhibited good activity against resistant bacteria and antioxidant activity by releasing TA in case of bacterial infection (alkaline). Furthermore, the CPT hydrogel exhibited coagulant ability and could rapidly stop bleeding within 30 s. The biocompatible hydrogel effectively accelerated wound healing in a full-thickness skin defect model by thickening granulation tissue, increasing collagen deposition, vascular proliferation, and M2-type macrophage polarization. In conclusion, this study demonstrates that multifunctional CPT hydrogel offers a candidate material with potential applications for infected skin wound healing.


Asunto(s)
Antibacterianos , Vendajes , Quitosano , Hidrogeles , Cicatrización de Heridas , Quitosano/química , Quitosano/análogos & derivados , Quitosano/farmacología , Quitosano/síntesis química , Cicatrización de Heridas/efectos de los fármacos , Hidrogeles/química , Hidrogeles/farmacología , Hidrogeles/síntesis química , Animales , Concentración de Iones de Hidrógeno , Ratones , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Povidona/química , Masculino , Staphylococcus aureus/efectos de los fármacos , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/química , Materiales Biocompatibles/síntesis química , Piel/efectos de los fármacos , Piel/patología
6.
Lancet Oncol ; 13(2): 163-71, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22154591

RESUMEN

BACKGROUND: The effect of the addition of adjuvant chemotherapy to concurrent chemoradiotherapy in locoregionally advanced nasopharyngeal carcinoma is unclear. We aimed to assess the contribution of adjuvant chemotherapy to concurrent chemoradiotherapy versus concurrent chemoradiotherapy alone. METHODS: We did an open-label phase 3 multicentre randomised controlled trial at seven institutions in China. Randomisation was by a computer-generated random number code. Patients were stratified by treatment centre and randomly assigned in blocks of four. Treatment allocation was not masked. We randomly assigned patients with non-metastatic stage III or IV (except T3-4N0) nasopharyngeal carcinoma to receive concurrent chemoradiotherapy plus adjuvant chemotherapy or concurrent chemoradiotherapy alone. Patients in both groups received 40 mg/m(2) cisplatin weekly up to 7 weeks, concurrently with radiotherapy. Radiotherapy was given as 2·0-2·27 Gy per fraction with five daily fractions per week for 6-7 weeks to a total dose of 66 Gy or greater to the primary tumour and 60-66 Gy to the involved neck area. The concurrent chemoradiotherapy plus adjuvant chemotherapy group subsequently received 80 mg/m(2) adjuvant cisplatin and 800 mg/m(2) per day fluorouracil for 120 h every 4 weeks for three cycles. Our primary endpoint was failure-free survival. We did efficacy analyses in our intention-to-treat population. Our trial is ongoing; in this report we present the 2 year survival results and acute toxic effects. This trial is registered with ClinicalTrials.gov, number NCT00677118. FINDINGS: 251 patients were assigned to the concurrent chemoradiotherapy plus adjuvant chemotherapy group and 257 to the concurrent chemoradiotherapy alone group. After a median follow-up of 37·8 months (range 1·3-61·0), the estimated 2 year failure-free survival rate was 86% (95% CI 81-90) in the concurrent chemoradiotherapy plus adjuvant chemotherapy group and 84% (78-88) in concurrent chemoradiotherapy only group (hazard ratio 0·74, 95% CI 0·49-1·10; p=0·13). Stomatitis was the most commonly reported grade 3 or 4 adverse event during both radiotherapy (76 of 249 patients in the concurrent chemoradiotherapy plus adjuvant chemotherapy group and 82 of 254 in the concurrent chemoradiotherapy alone group) and adjuvant chemotherapy (43 [21%] of 205 patients treated with adjuvant chemotherapy). INTERPRETATION: Adjuvant cisplatin and fluorouracil chemotherapy did not significantly improve failure-free survival after concurrent chemoradiotherapy in locoregionally advanced nasopharyngeal carcinoma. Longer follow-up is needed to fully assess survival and late toxic effects, but such regimens should not, at present, be used outside well-designed clinical trials. FUNDING: Sun Yat-sen University Clinical Research 5010 Programme (No 2007037), Science Foundation of Key Hospital Clinical Programme of Ministry of Health PR China (No 2010-178), and Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2010).


Asunto(s)
Quimioradioterapia/métodos , Quimioterapia Adyuvante/métodos , Neoplasias Nasofaríngeas/epidemiología , Neoplasias Nasofaríngeas/terapia , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma , China , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Supervivencia sin Enfermedad , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Estadificación de Neoplasias , Adulto Joven
7.
Pest Manag Sci ; 79(4): 1518-1527, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36519402

RESUMEN

BACKGROUND: RNA interference (RNAi) technology has been considered as a promising pest control strategy due to its species selectivity. One of the popular RNAs is exogenous double strand RNA (dsRNA). However, dsRNA is easily degraded by nucleases and is difficult to pass through the insect body walls, and these factors restrict the application of RNAi technology in pest management. Here, the brown planthopper (BPH, Nilaparvata lugens), a major hemipteran pest of rice in Asia countries was used as a model insect, and a dsRNA topical delivery system was constructed. RESULTS: The carrier part of the delivery system was composed of rosin-modified polyethylene glycol and chitosan, termed ROPE@C. When the N/P ratio was greater than 1:1.25, the dsRNA/ROPE@C complex encouraged full binding of the dsRNA. The gel electrophoresis results showed that ROPE@C improved the stability of dsRNA in the presence of nucleases in gut and lumen contents for at least 6 h and in the temperature range from 4 °C to 37 °C. The dsNlCHSA/ROPE@C/alkyl polyglycoside (APG) nano-formulation directly penetrated the body walls reaching hemocoel within 6 h, and consequently, the relative expression of chitin synthetase A (CHSA) in BPH was reduced by 54.3% and the mortality rate was 65.8%. CONCLUSION: We developed an appropriate delivery method for dsRNA application in BPH, which is helpful for a large-scale application of RNAi pesticides. © 2022 Society of Chemical Industry.


Asunto(s)
Quitosano , Hemípteros , Animales , Quitosano/metabolismo , Silenciador del Gen , Hemípteros/genética , Interferencia de ARN , ARN Bicatenario/metabolismo
8.
Eur J Radiol Open ; 11: 100526, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37953964

RESUMEN

Purpose: The purpose of this study was to investigate the difference between the quantitative MRI values of Wiberg type III and stable patellar cartilage, and to improve the accuracy of MRI quantification in early patellar cartilage damage. Methods: The knee joints of 94 healthy volunteers were scanned by a GE Signa Pioneer 3.0-T synthetic MRI machine. According to the Wiberg classification, the patella was divided into types I-III. Types I-II made up the stable patella group, and type III made up the unstable patella group. Two radiologists independently measured patellar cartilage thickness and quantitative synthetic MRI values (T1, T2, PD) in both groups. Interobserver agreement for quantitative variables was assessed using the Bland-Altman method. A third radiologist assessed differences in measurements. Results: The medial T2 and T1 value of Wiberg III patella did not show a normal distribution (all P > 0.05). Compared with the stable group, the Wiberg type III group had thinner cartilage of the medial surface of the patella (P < 0.05), lower cartilage T2 and PD values (P < 0.05), but a similar cartilage T1 value (P > 0.05). There was no significant difference in the cartilage thickness, T1, T2, or PD value of the lateral patella between the Wiberg type III and the stable group (P > 0.05). Conclusion: There were certain differences in the cartilage thickness of the medial surface of the patella and the quantitative value of synthetic MRI in Wiberg type III patellas. Quantitative studies of patellar cartilage MRI measurements need to consider the influence of patellar morphology.

9.
Int J Biol Macromol ; 224: 523-532, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36280178

RESUMEN

The mechanical mismatch between soft hydrated tissues and sutures has become a common negative impact on wound healing process. A novel method of coating multilayer polymer shells is thus reported to improve the mechanical performance of hydrogel sutures. It is suitable for tissue patching and shows advantages of convenient, efficient, and biosafety. Specifically, a precursor hydrogel (Cu@CMC) consisted of carboxymethyl chitosan and copper modified by carbon dots was used as the inner sheath, and then bonding the precursor hydrogel sheath with toughening polyethylene glycol network by anchoring sites composited from rigid chitosan shell integrated a whole structure. Subsequently, the whole system was soaked with EtOH, and rapid dehydration of EtOH was used to accelerate the entanglement process between the two coatings by constricting the molecular chains. Finally, an ideal suture (Cu-fiber) with both toughness and rigidness was obtained. The data showed that the tensile strength and biosafety of the hydrogel sutures prepared by the new strategy were significantly improved, and the skin, liver and vessel of rodents can be sutured without secondary damage. Moreover, it can inhibit inflammation response and promote the healing process of skin wound, indicating that the Cu-fiber will become a great candidate for tissue patching.


Asunto(s)
Quitosano , Quitosano/química , Polietilenglicoles/química , Piel , Cicatrización de Heridas , Hidrogeles/química
10.
Mater Horiz ; 10(3): 842-851, 2023 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-36689243

RESUMEN

The performance of chemical sensors is dominated by the perception of the target molecules via sensitive materials and the conduction of sensing signals through transducers. However, sensing and transduction are spatially and temporally independent in most chemical sensors, which poses a challenge for device miniaturization and integration. Herein, we proposed a sensing-transducing coupled strategy by embedding the high piezoresponse Sm-PMN-PT ceramic (d33 = ∼1500 pC N-1) into a moisture-sensitive polyetherimide (PEI) polymer matrix via electrospinning to conjugate the humidity perception and signal transduction synchronously and sympatrically. Through phase-field simulation and experimental characterization, we reveal the principle of design of the composition and topological structure of sensing-transducing coupled piezoelectric (STP) textiles in order to modulate the recognition, conversion, and sensitive component utilization ratio of the prepared active humidity sensors, achieving high sensitivity (0.9%/RH%) and fast response (20 s) toward ambient moisture. The prepared STP textile can be worn on the human body to realize emotion recognition, exercise status monitoring, and physiological stress identification. This work offers unprecedented insights into the coupling mechanism between chemisorption-related interfacial state and energy conversion efficiency and opens up a new paradigm for developing autonomous, multifunctional and highly sensitive flexible chemical sensors.


Asunto(s)
Dispositivos Electrónicos Vestibles , Humanos , Humedad , Monitoreo Biológico , Textiles
11.
Biosens Bioelectron ; 222: 114999, 2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36521206

RESUMEN

Electronic textiles are fundamentally changing the way we live. However, the inability to effectively recycle them is a considerable burden to the environment. In this study, we developed a cotton fiber-based piezoresistive textile (CF p-textile) for biomonitoring which is biocompatible, biodegradable, and environmentally friendly. These CF p-textiles were fabricated using a scalable dip-coating method to adhere MXene flakes to porous cotton cellulose fibers. The adhesion is made stronger by strong hydrogen bonding between MXene flakes and hierarchically porous cotton cellulose fibers. This cotton-fiber system provides a high sensitivity of 17.73 kPa-1 in a wide pressure range (100 Pa-30 kPa), a 2 Pa subtle pressure detection limit, fast response/recovery time (80/40 ms), and good cycle stability (over 5, 000 cycles). With its compelling sensing performance, the CF p-textile can detect various human biomechanical activities, including pulsation, muscle movement, and swallowing, while still being comfortable to wear. Moreover, the cotton cellulose is decomposed into low-molecular weight cellulose or glucose as a result of the 1,4-glycosidic bond breakage when exposed to acid or during natural degradation, which allows the electronic textile to be biodegradable. This work offers an ecologically-benign, cost-effective and facile approach to fabricating high-performance wearable bioelectronics.


Asunto(s)
Técnicas Biosensibles , Dispositivos Electrónicos Vestibles , Humanos , Fibra de Algodón , Monitoreo Biológico , Textiles , Celulosa
12.
Materials (Basel) ; 15(4)2022 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-35208115

RESUMEN

Coarse aggregate is the main component of asphalt mixtures, and differences in its morphology directly impact road performance. The utilization of standard aggregates can benefit the standard design and performance improvement. In this study, 3D printing technology was adopted to prepare artificial aggregates with specific shapes for the purpose of making the properties of artificial aggregates to be similar to the properties of natural aggregates. Through a series of material experiments, the optimal cement-based material ratio for the preparation of high-strength artificial aggregates and corresponding manufacturing procedures have been determined. The performance of the artificial aggregates has been verified by comparing the physical and mechanical properties with those of natural aggregates. Results indicate that using 3D printing technology to generate the standard coarse aggregate is feasible, but its high cost in implementation cannot be ignored. The 3D shape of the artificial aggregate prepared by the grouting molding process has a good consistency with the natural aggregate, and the relative deviation of the overall macro-scale volume index of the artificial aggregate is within 4%. The average Los Angeles abrasion loss of artificial cement-based aggregate is 15.2%, which is higher than that of diabase aggregate, but significantly lower than that of granite aggregate and limestone aggregate. In a nutshell, 3D printed aggregates prepared using the optimized cement-based material ratio and corresponding manufacturing procedures have superior physical and mechanical performance, which provides technical support for the test standardization and engineering application of asphalt pavements.

13.
Braz J Otorhinolaryngol ; 88(1): 53-62, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-32600962

RESUMEN

INTRODUCTION: A refractory cervical anastomotic fistula which postoperatively remains unhealed for more than 2 months under conservative care severely impacts the quality of life of the patient and potentially leads to anastomotic stricture after the fistula heals. It is widely accepted that, to avoid this complication, refractory cervical anastomotic fistulas should undergo more aggressive treatments. However, when and which surgical intervention should be considered is unclear. OBJECTIVE: This study was designed to evaluate the role of the pectoralis major myocutaneous flap in the management of refractory cervical anastomotic fistulas based on our experience of 6 cases and a literature review. METHODS: Six patients diagnosed with refractory cervical anastomotic fistula after esophagectomy treated using pectoralis major myocutaneous flap transfer were included in the study. The clinical data, surgical details, and treatment outcome were retrospectively analyzed. RESULTS: All patients survived the operations. One patient who had a circumferential anastomotic defect resulting from surgical exploration developed a mild fistula in the neo-anastomotic site in the 5th postoperative day, which healed after 7 days of conservative care. This patient developed an anastomotic stricture which was partially alleviated by an endoscopic anastomotic dilatation. All the other 5 patients had uneventful recoveries after operations and restored oral intake on the 10th-15th days after operation, and they tolerated normal diets without subsequent sequelae on follow-up. One patient developed both local and lung recurrence and died in 15 months after operation, while the other 5 patients survived with good tumor control during the follow-up of 25-53 months. CONCLUSION: The satisfactory treatment outcome in our study demonstrates that pectoralis major myocutaneous flap reconstruction is a reliable management modality for refractory cervical anastomotic fistulas after esophagectomy, particularly for those patients who experienced persistent fistulas after conservative wound care and repeated wound closures.


Asunto(s)
Fístula , Colgajo Miocutáneo , Procedimientos de Cirugía Plástica , Esofagectomía/efectos adversos , Humanos , Músculos Pectorales/cirugía , Calidad de Vida , Estudios Retrospectivos
14.
Int J Biol Macromol ; 221: 1259-1270, 2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36075309

RESUMEN

The treatment of traumatic spinal cord injury (SCI) remains challenging as the neuron regeneration is impaired by irregular cavity and apoptosis. An injectable in situ gelling hydrogel is therefore developed for the local delivery of cannabidiol (CBD) through a novel method based on polyelectrolyte (PEC) interaction of sodium carboxymethylcellulose (CMC) and chitosan (CS). It can be injected into the spinal cord cavity with a 26-gauge syringe before gelation, and gelled after 110 ± 10 s. Of note, the in-situ forming hydrogel has mechanical properties similar to spinal cord. Moreover, the CBD-loaded hydrogels sustain delivery of CBD for up to 72 h, resulting in reducing apoptosis in SCI by enhancing mitochondrial biogenesis. Importantly, the CBD-loaded hydrogels raise neurogenesis more than pure hydrogels both in vivo and in vitro, further achieving significant recovery of motor and urinary function in SCI rats. Thus, it suggested that CMC/CS/CBD hydrogels could be used as promising biomaterials for tissue engineering and SCI.


Asunto(s)
Cannabidiol , Quitosano , Traumatismos de la Médula Espinal , Ratas , Animales , Hidrogeles , Cannabidiol/farmacología , Biogénesis de Organelos , Traumatismos de la Médula Espinal/tratamiento farmacológico
15.
Adv Sci (Weinh) ; 9(13): e2105550, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35277947

RESUMEN

Piezoelectric nanocomposites with oxide fillers in a polymer matrix combine the merit of high piezoelectric response of the oxides and flexibility as well as biocompatibility of the polymers. Understanding the role of the choice of materials and the filler-matrix architecture is critical to achieving desired functionality of a composite towards applications in flexible electronics and energy harvest devices. Herein, a high-throughput phase-field simulation is conducted to systematically reveal the influence of morphology and spatial orientation of an oxide filler on the piezoelectric, mechanical, and dielectric properties of the piezoelectric nanocomposites. It is discovered that with a constant filler volume fraction, a composite composed of vertical pillars exhibits superior piezoelectric response and electromechanical coupling coefficient as compared to the other geometric configurations. An analytical regression is established from a linear regression-based machine learning model, which can be employed to predict the performance of nanocomposites filled with oxides with a given set of piezoelectric coefficient, dielectric permittivity, and stiffness. This work not only sheds light on the fundamental mechanism of piezoelectric nanocomposites, but also offers a promising material design strategy for developing high-performance polymer/inorganic oxide composite-based wearable electronics.


Asunto(s)
Nanocompuestos , Electrónica , Aprendizaje Automático , Óxidos , Polímeros
16.
Nat Commun ; 13(1): 4867, 2022 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-35982033

RESUMEN

Polymer-ceramic piezoelectric composites, combining high piezoelectricity and mechanical flexibility, have attracted increasing interest in both academia and industry. However, their piezoelectric activity is largely limited by intrinsically low crystallinity and weak spontaneous polarization. Here, we propose a Ti3C2Tx MXene anchoring method to manipulate the intermolecular interactions within the all-trans conformation of a polymer matrix. Employing phase-field simulation and molecular dynamics calculations, we show that OH surface terminations on the Ti3C2Tx nanosheets offer hydrogen bonding with the fluoropolymer matrix, leading to dipole alignment and enhanced net spontaneous polarization of the polymer-ceramic composites. We then translated this interfacial bonding strategy into electrospinning to boost the piezoelectric response of samarium doped Pb (Mg1/3Nb2/3)O3-PbTiO3/polyvinylidene fluoride composite nanofibers by 160% via Ti3C2Tx nanosheets inclusion. With excellent piezoelectric and mechanical attributes, the as-electrospun piezoelectric nanofibers can be easily integrated into the conventional shoe insoles to form a foot sensor network for all-around gait patterns monitoring, walking habits identification and Metatarsalgi prognosis. This work utilizes the interfacial coupling mechanism of intermolecular anchoring as a strategy to develop high-performance piezoelectric composites for wearable electronics.


Asunto(s)
Nanofibras , Polímeros
17.
Nanomaterials (Basel) ; 11(7)2021 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-34361139

RESUMEN

K0.5Na0.5NbO3 is considered as one of the most promising lead-free piezoelectric ceramics in the field of wearable electronics because of its excellent piezoelectric properties and environmental friendliness. In this work, the temperature-dependent longitudinal piezoelectric coefficient d33* was investigated in K0.5Na0.5NbO3 single crystals via the Landau-Ginzburg-Devonshire theory. Results show that the piezoelectric anisotropy varies with the temperature and the maximum of d33max* deviates from the polar direction of the ferroelectric phase. In the tetragonal phase, d33maxt* parallels with cubic polarization direction near the tetragonal-cubic transition region, and then gradually switches toward the nonpolar direction with decreasing temperatures. The maximum of d33o* in the orthorhombic phase reveals a distinct varying trend in different crystal planes. As for the rhombohedral phase, slight fluctuation of the maximum of d33r* was observed and delivered a more stable temperature-dependent maximum d33maxr* and its corresponding angle θmax in comparison with tetragonal and orthorhombic phases. This work not only sheds some light on the temperature-dependent phase transitions, but also paves the way for the optimization of piezoelectric properties in piezoelectric materials and devices.

18.
Carbohydr Polym ; 254: 117281, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357857

RESUMEN

Practical application of powder photocatalysts is far from satisfying due to their low photon utilization, inconvenient recovery and potential environmental risk. In this study, an easily recoverable, environmentally friendly and highly transparent floatable magnetic photocatalyst carrier was prepared based on biopolymer alginate and Fe3O4 particles. Further, three different types of photocatalysts were chosen as model semiconductor photocatalysts and loaded on the shell of the carriers. The freeze process facilitated the formation of internal cavities that enhanced floating ability and transparency of the spheres. Meanwhile, the excellent floating performance offered massive reaction sites for pollutants reacting with photocatalysts, O2 and photons on the air/water interface. Photodegradation results showed all three floatable hybrid photocatalysts exhibited enhanced photocatalytic efficiencies compared to the virgin photocatalysts. In short, the carrier can integrate excellent floating ability, environmental friendliness and full recycling with good stability, and it can greatly improve the photocatalytic efficiency of various powder semiconductor photocatalysts.

19.
Carbohydr Polym ; 259: 117710, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33673989

RESUMEN

Harmful algal blooms induce severe environmental problems. It is challenging to remove algae by the current available treatments involving complicate process and costly instruments. Here, we developed a CaO2@PEG-loaded water-soluble self-branched chitosan (CP-SBC) system, which can remove algae from water in one-step without additional instrumentation. This approach utilizes a novel flocculant (self-branched chitosan) integrated with flotation function (induced by CaO2@PEG). CP-SBC exhibited better flocculation performance than commercial flocculants, which is attributed to the enhanced bridging and sweeping effect of branched chitosan. CP-SBC demonstrated outstanding biocompatibility, which was verified by zebrafish test and algae activity test. CaO2@PEG-loaded self-branched chitosan can serve as an "Air flotation system" to spontaneous float the flocs after flocculation by sustainably released O2. Furthermore, CP-SBC can improve water quality through minimizing dissolved oxygen depletion and reducing total phosphorus concentrations.


Asunto(s)
Quitosano/química , Floraciones de Algas Nocivas/fisiología , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Compuestos de Calcio/química , Floculación/efectos de los fármacos , Floraciones de Algas Nocivas/efectos de los fármacos , Cinética , Larva/efectos de los fármacos , Óxidos/química , Oxígeno/química , Fósforo/química , Polietilenglicoles/química , Porosidad , Pez Cebra/crecimiento & desarrollo , Pez Cebra/fisiología
20.
Int J Biol Macromol ; 167: 1211-1220, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33189756

RESUMEN

Bone related-bacterial diseases including wound infections and osteomyelitis (OM) remain a serious problem accompanied with amputation in most severe cases. In this work, we report an exceptional effective antibacterial alginate aerogel, which consists of tigecycline (TGC) and octahedral Cu crystal as an organo-inorganic synergy platform for antibacterial and local infection therapy applications. The alginate aerogel could greatly prolong the release of copper ions and maintain effective antibacterial concentration over 18 days. The result of in-vitro experiments demonstrated that the alginate aerogel has an exceptional effective function on antibacterial activity. Cytotoxicity tests indicated that the alginate aerogel has low biological toxicity (average cell viability >75%). These remarkable results suggested that the alginate aerogel exhibits great potential for the treatment of OM, and has a prosperous future of application in bone tissue engineering.


Asunto(s)
Alginatos/química , Antibacterianos/química , Huesos/efectos de los fármacos , Cobre/química , Escherichia coli/efectos de los fármacos , Geles/química , Alginatos/síntesis química , Alginatos/toxicidad , Antibacterianos/farmacología , Infecciones Bacterianas/tratamiento farmacológico , Huesos/microbiología , Proliferación Celular/efectos de los fármacos , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacología , Geles/síntesis química , Geles/toxicidad , Células Endoteliales de la Vena Umbilical Humana , Humanos , Iones/química , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos , Tigeciclina/química
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