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1.
Pediatr Nephrol ; 39(4): 1125-1133, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37783894

RESUMEN

BACKGROUND: Pathogenesis and relapse of steroid-sensitive nephrotic syndrome (SSNS) are primarily associated with infection. Dental caries is the most common chronic progressive oral infection in children. However, clinical studies of SSNS combined with dental caries in children are rare. METHODS: In our retrospective cohort study from January 2021 to June 2022, 145 children with SSNS were included in the baseline analysis and 105 in the follow-up analysis. The follow-up period was 1 year. The primary study endpoints were the relapse-free period and frequently relapsing nephrotic syndrome (FRNS). Secondary endpoints included the number and triggers of relapses and concomitant medications. RESULTS: The median age was 5.5 years, with a caries rate of 60.7%, the mean DMFT/dmft was 3.86, and the caries filling rate was 1.6%. Except for the lower proportion of high household income and high parental education observed in the caries group, no statistical differences were found when comparing the other baseline data with the non-caries group. The caries group had a shorter relapse-free period and a lower 1-year cumulative relapse-free survival rate (HR = 1.90, 95% CI 1.17-3.09, P = 0.009). Univariate regression analysis showed caries associated with FRNS (OR = 2.714, 95% CI 1.021-7.219, P = 0.045), but the correlation no longer remained in the multivariate analysis. Additionally, seven cases of caries-derived pulpal periapical inflammation triggered SSNS relapses. The caries group had more infection triggers and concomitant medication use. CONCLUSION: Dental caries and relapse of SSNS are potentially associated, but careful evaluation is needed.


Asunto(s)
Caries Dental , Síndrome Nefrótico , Niño , Humanos , Preescolar , Síndrome Nefrótico/tratamiento farmacológico , Síndrome Nefrótico/epidemiología , Estudios Retrospectivos , Caries Dental/epidemiología , Inflamación , Recurrencia
2.
BMC Psychiatry ; 24(1): 246, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38566067

RESUMEN

BACKGROUND: The Hospital Consultants' Job Stress Questionnaire (HCJSQ) has been widely used to assess sources and levels of job stress. However, its reliability and validity among Chinese dental workers have not been extensively studied. The objective of this study was to assess the reliability and validity of the HCJSQ specifically in Chinese dental workers. METHODS: The HCJSQ was used to explore the sources and the global ratings of job stress among Chinese dental workers. To assess the reliability and validity of the HCJSQ, various statistical measures were employed, including Cronbach's alpha coefficient, Spearman-Brown coefficient, Spearman correlation coefficient, exploratory factor analysis, confirmatory factor analysis, convergent validity, and discriminant validity. RESULTS: Of the participants, 526 (17.4%) reported high levels of stress, while 1,246 (41.3%) and 1,248 (41.3%) reported moderate and low levels of stress, respectively. The Cronbach's alpha coefficient for the modified HCJSQ was 0.903, and the Spearman-Brown coefficient was 0.904. Spearman correlation coefficient between individuals' items and the total score ranged from 0.438 to 0.785 (p < 0.05). Exploratory factor analysis revealed that three factors accounted for 60.243% of the total variance. Confirmatory factor analysis demonstrated factor loadings between 0.624 and 0.834 on the specified items. The fit indices of the confirmatory factor analysis indicated good model fit, with a Root Mean Square Error of Approximation of 0.064, Normative Fit Index of 0.937, Comparative Fit Index of 0.952, Incremental Fit Index of 0.952, Tucker-Lewis index of 0.941, and Goodness of Fit Index of 0.944. Additionally, the convergent validity and discriminant validity showed a good fit for the three-factor model. CONCLUSION: The results of this study confirm that Chinese dental workers experience high levels of stress, and the three-factor model of the HCJSQ proves to be a suitable instrument for evaluating the sources and levels of job stress among Chinese dental workers. Therefore, it is imperative that relevant entities such as hospitals, medical associations, and government take appropriate measures to address the existing situation.


Asunto(s)
COVID-19 , Estrés Laboral , Humanos , Reproducibilidad de los Resultados , Consultores , Pandemias , Psicometría , China , Estrés Laboral/diagnóstico , Encuestas y Cuestionarios , Análisis Factorial , Hospitales
3.
Chemistry ; 29(33): e202300528, 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-36905206

RESUMEN

A friction layer with stability and durability is important to promote the practical application of triboelectric nanogenerators (TENGs). In this work, a two-dimensional cobalt coordination polymer (Co-CP) was successfully synthesized using cobalt nitrate, 4,4',4''-tricarboxyltriphenylamine and 2,2'-bipyridine. To clearly clarify the effect of the doping proportions of Co-CP and the types of composite polymers on the output performance of the TENG, Co-CP was combined with two organic polymers having different polarities (polyvinylidene fluoride (PVDF) and ethyl cellulose (EC)) to form a series of composite films, which were used as the friction electrode materials to fabricate TENGs. Electrical characterizations indicated that a high output current and voltage were obtained from the TENG based on 15 wt.% Co-CP incorporated in PVDF (Co-CP@PVDF), which could be further improved by the Co-CP@EC composite film at the same doping ratio. Furthermore, the optimally fabricated TENG was demonstrated to prevent electrochemical corrosion of carbon steel.


Asunto(s)
Polímeros , Polivinilos , Carbono , Cobalto
4.
Int Wound J ; 20(4): 1020-1032, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36184261

RESUMEN

The treatment of traumatic wounds with exposed bone or tendons is often challenging. An induced membrane (IM) is used to reconstruct bone defects, as it provides an effective and sufficient blood supply for bone and soft-tissue reconstruction. This study explored a novel two-stage strategy for wound management, consisting of initial wound coverage with polymethyl methacrylate (PMMA) and an autologous split-thickness skin graft under the IM. Fifty inpatients were enrolled from December 2016 to December 2019. Each patient underwent reconstruction according to a two-stage process. In the first stage, the defect area was thoroughly debrided, and the freshly treated wound was then covered using PMMA cement. After 4-6 weeks, during the second stage, the PMMA cement was removed to reveal an IM covering the exposed bone and tendon. An autologous split-thickness skin graft was then performed. Haematoxylin and eosin (H&E) staining and immunohistochemical analysis of vascular endothelial growth factor (VEGF), CD31 and CD34 were used to evaluate the IM and compare it with the normal periosteal membrane (PM). The psychological status and the Lower Extremity Function Scale (LEFS) as well as any complications were recorded at follow-up. We found that all skin grafts survived and evidenced no necrosis or infection. H&E staining revealed vascularised tissue in the IM, and immunohistochemistry showed a larger number of VEGF-, CD31- and CD34-positive cells in the IM than in the normal PM. The duration of healing in the group was 5.40 ± 1.32 months with a mean number of debridement procedures of 1.92 ± 0.60. There were two patients with reulceration in the group. The self-rating anxiety scale scores ranged from 35 to 60 (mean 48.02 ± 8.12). Postoperatively, the LEFS score was 50.10 ± 9.77. Finally, our strategy for the management of a non-healing wound in the lower extremities, consisting of an IM in combination with skin grafting, was effective, especially in cases in which bony structures were exposed in the elderly. The morbidity rate was low.


Asunto(s)
Polimetil Metacrilato , Trasplante de Piel , Humanos , Anciano , Polimetil Metacrilato/uso terapéutico , Factor A de Crecimiento Endotelial Vascular , Estudios de Seguimiento , Desbridamiento
5.
Small ; 18(10): e2107150, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35266314

RESUMEN

Unidirectional water transport performance is vital for maintaining human thermal and wet comfort in the field of garment materials. In this work, a 3D orthogonal woven fabric (3DOWF) with excellent one-way transport capacity and mechanical properties is developed via 3D weaving and plasma treatment. The 3DOWF consists of polyester yarns (first layer), cotton yarns (second layer), and viscose yarns (third layer) with successively enhanced water absorption capacity. This allows droplets to penetrate spontaneously from the hydrophobic layer to the hydrophilic layer but not vice versa. Moreover, the Coolmax yarn with the core suction effect in the Z-direction and the plasma-treated polyester of the 3DOWF are shown to efficiently speed up the water transport process. In particular, the water penetration rate of the 3DOWF reaches 25 µl s-1 . In turn, the surface temperature after water absorption is increased by 2.6 °C compared with the cotton fabric, while the tensile strengths in the weft and warp directions of the 3DOWF are 49.62 and 18 MPa, respectively. These values represent the best insulation and mechanical characteristics thus far reported among unidirectional water transport fabrics. Therefore, the 3DOWF has great potential for use in watchbands, backpack belts, insoles, and other functional textiles.


Asunto(s)
Cuerpo Humano , Textiles , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Poliésteres/química , Agua
6.
Small ; 17(19): e2100066, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33792159

RESUMEN

Natural materials, such as silk, nacre, and bone, possess superior mechanical properties which are derived from their unique hierarchical structures. Individual carbon nanotubes (CNTs) are considered as one of the strongest materials. However, macroscopic CNT fibers usually have breaking strength far below that of individual CNTs. In this work, by mimicking the structure of natural silk fibers, strong and stiff CNT fibers are prepared by infiltrating silk fibroin (SF) into CNT fibers. There are abundant hydrogen bonds in SF, contributing to the enhanced interactions between neighboring CNTs. Glycerol is selected to promote the formation of ß-sheet conformation in SF, leading to further enhanced strength and modulus. Remarkably, the SF infiltrated CNT fibers show breaking strength of 1023 MPa, toughness of 10.3 MJ m-3 , and Young's modulus of 81.3 GPa, which are 250%, 132%, and 442% of the pristine CNT fibers. The structure of the SF and the interactions between CNTs and SF are studied via Fourier transformed infrared spectroscopy and molecular dynamics simulation. Mimicking the hierarchical structures of natural silk fibers and enhance the interfacial load transfer by infiltrating SF are effective for reinforcing CNT fibers, which may be useful in the design and preparation of other structural materials.


Asunto(s)
Fibroínas , Nanotubos de Carbono , Biomimética , Fibra de Carbono , Seda
7.
J Nanobiotechnology ; 19(1): 453, 2021 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-34963449

RESUMEN

BACKGROUND: The interactions between nanoparticles (NPs) and plasma proteins form a protein corona around NPs after entering the biological environment, which provides new biological properties to NPs and mediates their interactions with cells and biological barriers. Given the inevitable interactions, we regard nanoparticle‒protein interactions as a tool for designing protein corona-mediated drug delivery systems. Herein, we demonstrate the successful application of protein corona-mediated brain-targeted nanomicelles in the treatment of glioma, loading them with paclitaxel (PTX), and decorating them with amyloid ß-protein (Aß)-CN peptide (PTX/Aß-CN-PMs). Aß-CN peptide, like the Aß1-42 peptide, specifically binds to the lipid-binding domain of apolipoprotein E (ApoE) in vivo to form the ApoE-enriched protein corona surrounding Aß-CN-PMs (ApoE/PTX/Aß-CN-PMs). The receptor-binding domain of the ApoE then combines with low-density lipoprotein receptor (LDLr) and LDLr-related protein 1 receptor (LRP1r) expressed in the blood-brain barrier and glioma, effectively mediating brain-targeted delivery. METHODS: PTX/Aß-CN-PMs were prepared using a film hydration method with sonication, which was simple and feasible. The specific formation of the ApoE-enriched protein corona around nanoparticles was characterized by Western blotting analysis and LC-MS/MS. The in vitro physicochemical properties and in vivo anti-glioma effects of PTX/Aß-CN-PMs were also well studied. RESULTS: The average size and zeta potential of PTX/Aß-CN-PMs and ApoE/PTX/Aß-CN-PMs were 103.1 nm, 172.3 nm, 7.23 mV, and 0.715 mV, respectively. PTX was efficiently loaded into PTX/Aß-CN-PMs, and the PTX release from rhApoE/PTX/Aß-CN-PMs exhibited a sustained-release pattern in vitro. The formation of the ApoE-enriched protein corona significantly improved the cellular uptake of Aß-CN-PMs on C6 cells and human umbilical vein endothelial cells (HUVECs) and enhanced permeability to the blood-brain tumor barrier in vitro. Meanwhile, PTX/Aß-CN-PMs with ApoE-enriched protein corona had a greater ability to inhibit cell proliferation and induce cell apoptosis than taxol. Importantly, PTX/Aß-CN-PMs exhibited better anti-glioma effects and tissue distribution profile with rapid accumulation in glioma tissues in vivo and prolonged median survival of glioma-bearing mice compared to those associated with PMs without the ApoE protein corona. CONCLUSIONS: The designed PTX/Aß-CN-PMs exhibited significantly enhanced anti-glioma efficacy. Importantly, this study provided a strategy for the rational design of a protein corona-based brain-targeted drug delivery system. More crucially, we utilized the unfavorable side of the protein corona and converted it into an advantage to achieve brain-targeted drug delivery.


Asunto(s)
Antineoplásicos/administración & dosificación , Apolipoproteínas E/administración & dosificación , Encéfalo/efectos de los fármacos , Glioma/tratamiento farmacológico , Nanopartículas/administración & dosificación , Corona de Proteínas , Péptidos beta-Amiloides/administración & dosificación , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/farmacocinética , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Apolipoproteínas E/química , Apolipoproteínas E/farmacocinética , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Sistemas de Liberación de Medicamentos , Glioma/metabolismo , Humanos , Ratones , Micelas , Nanopartículas/química , Paclitaxel/administración & dosificación , Paclitaxel/química , Paclitaxel/farmacocinética , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/química , Fragmentos de Péptidos/farmacocinética , Poliésteres/administración & dosificación , Poliésteres/química , Poliésteres/farmacocinética , Polietilenglicoles/administración & dosificación , Polietilenglicoles/química , Polietilenglicoles/farmacocinética , Corona de Proteínas/química
8.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(4): 590-594, 2021 Aug.
Artículo en Zh | MEDLINE | ID: mdl-34494531

RESUMEN

Objective To investigate the oral health status and awareness of urban children in Lhasa,aiming to provide a data basis for the prevention and treatment of children's caries and the promotion of oral health education. Methods A total of 504 Tibetan students were selected by cluster sampling from 2 primary schools in Chengguan District of Lhasa.All the participants were required to take oral health examination and complete a questionnaire about oral health awareness and behavior. Results The caries prevalence rate and mean decayed-missing-filled tooth(DMFT)of permanent teeth were 75.00% and 2.18±1.91,respectively.The rates of pit and fissure sealant and filling of permanent teeth were 3.77% and 6.81%,respectively.The caries prevalence rate of first permanent molars was 47.62%.The mean DMFT of permanent teeth and caries prevalence rate of first permanent molar were significantly higher in female group(P=0.001 and P=0.007,respectively).The prevalence rate of dental fluorosis was 61.51%,and the detection rate of dental calculus was 71.83%.Multivariate logistic regression analysis showed that prevalence of caries was influenced by many independent factors including gender,oral health awareness,intention of dental intervention,and dental experience. Conclusion High caries prevalence rate,low filling rate,and poor oral hygiene and health awareness were found among the primary school students in Lhasa,which require continuous dentistry investment and oral health education for the local students and their parents.


Asunto(s)
Caries Dental , Salud Bucal , Niño , Índice CPO , Caries Dental/epidemiología , Femenino , Humanos , Higiene Bucal , Prevalencia , Instituciones Académicas , Estudiantes , Encuestas y Cuestionarios
9.
J Sep Sci ; 43(8): 1514-1522, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31984639

RESUMEN

In this study, porous sandwich structure Fe3 O4 nanoparticles coated by polyhedral oligomeric silsesquioxanes and ß-cyclodextrin were prepared by surface polymerization and were used as the magnetic solid phase extraction adsorbent for the extraction and determination of carbaryl and carbofuran. The Fe3 O4 nanoparticles coated with polyhedral oligomeric silsesquioxanes and ß-cyclodextrin were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, vibrating sample magnetometry, and scanning electron microscopy. After optimizing the extraction conditions, a method that combined magnetic solid phase extraction with high-performance liquid chromatography was developed for the determination of carbaryl and carbofuran in apple. The method exhibited a good linearity in the range of 2-400 µg/kg for carbaryl and carbofuran (R2  = 0.9995), respectively. The limits of detection were 0.5 µg/kg of carbaryl and 0.7 µg/kg for carbofuran in apple, respectively. Extraction recoveries ranged from 94.2 to 103.1% with the preconcentration factor of 300 and the relative standard deviations were less than 5.9%. These results indicated that the method combined magnetic solid phase extraction with high-performance liquid chromatography and was promising for the determination of carbaryl and carbofuran at trace amounts.


Asunto(s)
Carbaril/aislamiento & purificación , Carbofurano/aislamiento & purificación , Nanopartículas de Magnetita/química , Siloxanos/química , Extracción en Fase Sólida , beta-Ciclodextrinas/química , Carbaril/química , Carbofurano/química , Fenómenos Magnéticos
10.
Bioprocess Biosyst Eng ; 43(3): 529-540, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31720769

RESUMEN

Simultaneous nitrification and denitrification (SND) during treating hydrolyzed polyacrylamide (HPAM) containing wastewater were explored in an aerobic biofilm reactor biosystem. Here, loofah sponges as the environment-friendly and low-cost material were applied as the carriers in this biosystem. The removal efficiencies of HPAM and total nitrogen (TN) reached 43.6% and 54.3%, respectively, after 120 days stabilized running periods. Moreover, the structure of loofah sponges affected anaerobic microenvironment significantly which was indispensable for realizing a high-performance of SND. Key microorganisms in this biosystem included nitrobacteria, denitrobacteria and HPAM-biodegrading bacteria. The abundance of nitrobacteria and denitrobacteria on the biofilm was increased by 17.2% and 15.3%, respectively, through cultivation. Meanwhile, the biotransformation mechanisms of HPAM and diverse valence of nitrogen under different chemical oxygen demand (COD)/N and dissolved oxygen (DO) conditions were investigated. When COD/N and DO were 8:1 and 2 mg/L, HPAM biodegradation, SND efficiency and TN removal achieved their maximum, and the values were 54.3%, 92.3% and 60.1%, respectively. Key enzyme activities also reached their maximum in this condition. The optimal COD/N and DO was pivotal to achieve the high-performance of SND, and it was closely correlated with HPAM biodegradation. Meanwhile, SND could facilitate the biotransformation of HPAM.


Asunto(s)
Resinas Acrílicas/química , Bacterias/metabolismo , Biopelículas , Luffa , Nitrificación , Aguas Residuales , Aerobiosis , Reactores Biológicos , Biotransformación , Hidrólisis
11.
Eur J Orthod ; 41(4): 333-342, 2019 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-30169774

RESUMEN

OBJECTIVE: The role of long non-coding ribonucleic acids (lncRNAs) during orthodontic tooth movement remains unclear. We explored the lncRNA landscape of periodontal ligament stem cells (PDLSCs) subjected to compressive force. MATERIALS AND METHODS: PDLSCs were subjected to static compressive stress (2 g/cm2) for 12 hours. Total RNA was then extracted and sequenced to measure changes in lncRNA and messenger RNA (mRNA) expression levels. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression levels of certain lncRNAs. Differential expression analysis as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were also performed. RESULTS: In total, 90 lncRNAs and 519 mRNAs were differentially expressed in PDLSCs under compressive stress. Of the lncRNAs, 72 were upregulated and 18 downregulated. The levels of eight lncRNAs of interest (FER1L4, HIF1A-AS2, MIAT, NEAT1, ADAMTS9-AS2, LUCAT1, MIR31HG, and DHFRP1) were measured via qRT-PCR, and the results were found to be consistent with those of RNA sequencing. GO and KEGG pathway analyses showed that a wide range of biological functions were expressed during compressive loading; most differentially expressed genes were involved in extracellular matrix organization, collagen fibril organization, and the cellular response to hypoxia. CONCLUSIONS: The lncRNA expression profile was significantly altered in PDLSCs subjected to compressive stress. These findings expand our understanding of molecular regulation in the mechanoresponse of PDLSCs.


Asunto(s)
ARN Largo no Codificante/genética , Perfilación de la Expresión Génica , Ligamento Periodontal , ARN Mensajero , Células Madre
12.
Acta Pharmacol Sin ; 39(2): 261-274, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29388568

RESUMEN

Melanoma is the deadliest type of skin cancer. CD20+ melanoma stem cells (CSCs) are pivotal for metastasis and initiation of melanoma. Therefore, selective elimination of CD20+ melanoma CSCs represents an effective treatment to eradicate melanoma. Salinomycin has emerged as an effective drug toward various CSCs. Due to its poor solubility, its therapeutic efficacy against melanoma CSCs has never been evaluated. In order to target CD20+ melanoma CSCs, we designed salinomycin-loaded lipid-polymer nanoparticles with anti-CD20 aptamers (CD20-SA-NPs). Using a single-step nanoprecipitation method, salinomycin-loaded lipid-polymer nanoparticles (SA-NPs) were prepared, then CD20-SA-NPs were obtained through conjugation of thiolated anti-CD20 aptamers to SA-NPs via a maleimide-thiol reaction. CD20-SA-NPs displayed a small size of 96.3 nm, encapsulation efficiency higher than 60% and sustained drug release ability. The uptake of CD20-SA-NPs by CD20+ melanoma CSCs was significantly higher than that of SA-NPs and salinomycin, leading to greatly enhanced cytotoxic effects in vitro, thus the IC50 values of CD20-SA-NPs were reduced to 5.7 and 2.6 µg/mL in A375 CD+20 cells and WM266-4 CD+ cells, respectively. CD20-SA-NPs showed a selective cytotoxicity toward CD20+ melanoma CSCs, as evidenced by the best therapeutic efficacy in suppressing the formation of tumor spheres and the proportion of CD20+ cells in melanoma cell lines. In mice bearing melanoma xenografts, administration of CD20-SA-NPs (salinomycin 5 mg·kg-1·d-1, iv, for 60 d) showed a superior efficacy in inhibition of melanoma growth compared with SA-NPs and salinomycin. In conclusion, CD20 is a superior target for delivering drugs to melanoma CSCs. CD20-SA-NPs display effective delivery of salinomycin to CD20+ melanoma CSCs and represent a promising treatment for melanoma.


Asunto(s)
Antineoplásicos/uso terapéutico , Portadores de Fármacos/uso terapéutico , Melanoma/tratamiento farmacológico , Nanopartículas/uso terapéutico , Células Madre Neoplásicas/efectos de los fármacos , Piranos/uso terapéutico , Animales , Antígenos CD20/química , Antineoplásicos/farmacología , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/metabolismo , Aptámeros de Nucleótidos/uso terapéutico , Aptámeros de Nucleótidos/toxicidad , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Portadores de Fármacos/toxicidad , Humanos , Lecitinas/química , Lecitinas/metabolismo , Lecitinas/uso terapéutico , Lecitinas/toxicidad , Ratones Endogámicos BALB C , Nanopartículas/química , Nanopartículas/metabolismo , Nanopartículas/toxicidad , Tamaño de la Partícula , Polietilenglicoles/química , Polietilenglicoles/metabolismo , Polietilenglicoles/uso terapéutico , Polietilenglicoles/toxicidad , Piranos/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
13.
Prep Biochem Biotechnol ; 48(3): 218-225, 2018 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-29528267

RESUMEN

Sodium percarbonate (SP), a kind of alkaline strong oxidant, was applied to corncob pretreatment. The optimized pretreatment conditions were at 4% (w/v) SP concentration with solid-to-liquid (SLR) ratio of 1:10 treating for 4 hr at 60°C. This pretreatment resulted in 91.06% of cellulose and 84.08% of hemicellulose recoveries with 34.09% of lignin removal in corncob. The reducing sugar yield from SP-pretreated corncob was 0.56 g/g after 72 hr of enzymatic hydrolysis, 1.75-folds higher than that from raw corncob. 2,3-butanediol production by Enterobacer cloacae in simultaneous saccharification fermentation was 29.18 g/L using SP-pretreated corncob as a substrate, which was 11.12 times of that using raw corncob. Scanning electron microscope, X-ray diffraction, and Fourier transform infrared spectra analysis indicated that physical characteristics, crystallinity, and structure of corncob had changed obviously after SP pretreatment. This simple and novel pretreatment method was effective for delignification and carbohydrate retention in microbial production of 2,3-butanediol from lignocellulose biomass.


Asunto(s)
Biocombustibles , Butileno Glicoles/metabolismo , Carbonatos/metabolismo , Enterobacter cloacae/metabolismo , Microbiología Industrial/métodos , Zea mays/metabolismo , Biocombustibles/análisis , Biocombustibles/microbiología , Butileno Glicoles/análisis , Celulosa/metabolismo , Fermentación , Hidrólisis , Lignina/metabolismo , Polisacáridos/metabolismo
14.
J Sci Food Agric ; 98(7): 2540-2547, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29028116

RESUMEN

BACKGROUND: ß-mannanase is a key enzyme for hydrolyzing mannan, a major constituent of hemicellulose, which is the second most abundant polysaccharide in nature. Different structural domains greatly affect its biochemical characters and catalytic efficiency. However, the effects of linker and carbohydrate-binding module (CBM) on ß-mannanase from Trichoderma reesei (Man1) have not yet been fully described. The present study aimed to determine the influence of different domains on the expression efficiency, biochemical characteristics and hemicellulosic deconstruction of Man1. RESULTS: The expression efficiency was improved after truncating CBM. Activities of Man1 and Man1ΔCBM (CBM) in the culture supernatant after 168 h of induction were 34.5 and 42.9 IU mL-1 , although a value of only 0.36 IU mL-1 was detected for Man1ΔLCBM (lacking CBM and linker). Man1 showed higher thermostability than Man1ΔCBM at low temperature, whereas Man1ΔCBM had a higher specificity for galactomannan (Km = 2.5 mg mL-1 ) than Man1 (Km = 4.0 mg mL-1 ). Both Man1 and Man1ΔCBM could synergistically improve the hydrolysis of cellulose, galactomannan and pretreated sugarcane bagasse, with a 10-30% improvement of the reducing sugar yield. CONCLUSION: Linker and CBM domains were vital for mannanase activity and expression efficiency. CBM affected the thermostability and adsorption ability of Man1. The results obtained in the present study should help guide the rational design and directional modification of Man with respect to improving its catalytic efficiency. © 2017 Society of Chemical Industry.


Asunto(s)
Proteínas Fúngicas/química , Saccharum/química , Trichoderma/enzimología , beta-Manosidasa/química , Biocatálisis , Celulosa/química , Estabilidad de Enzimas , Proteínas Fúngicas/metabolismo , Galactosa/análogos & derivados , Hidrólisis , Mananos/química , beta-Manosidasa/metabolismo
15.
Arthroscopy ; 33(3): 608-616, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27964968

RESUMEN

PURPOSE: To evaluate the convergent validity, precision, and completion times for the Physical Function Computerized Adaptive Test (PF-CAT) in a sports medicine patient population relative to standard measures of knee and shoulder function. METHODS: We reviewed all patient visits from April through September 2014 with either knee or shoulder complaints from a university-based sports medicine clinic, during which PF-CAT, Single Assessment Numerical Evaluation (SANE), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) outcome scores for shoulder patients and PF-CAT, SANE, and International Knee Documentation Committee (IKDC) scores for knee patients were obtained, with an initial visit or one follow-up visit included in the study. Spearman correlation was used to evaluate pairwise agreement among scores. The McNemar χ2 test was used to evaluate a difference in the number of times floor and ceiling values occurred. Wilcoxon signed rank tests were used to compare differences in completion times. RESULTS: In total, 415 shoulder and 450 knee clinical evaluations qualified for inclusion in the study. A high correlation was found between IKDC and PF-CAT scores (r = 0.75, P < .0001), and a moderately high correlation was found between PF-CAT and both SST (r = 0.68, P < .0001) and ASES (r = 0.63, P < .0001) scores. Maximum differences in the sum of floor-ceiling values versus the PF-CAT were 15% for the SST (P < .0001), 2.5% for the ASES (ceiling only, P = .0133), and 5.8% for the shoulder SANE (floor P = .0012, ceiling P = .0269). The PF-CAT had values of 0.4% for the shoulder and 0.6% for the knee. Zero percent of IKDC scores but 6.9% of knee SANE scores hit floor or ceiling values (floor P = .0019, ceiling P = .0007). The PF-CAT median completion time was lower at 55 seconds versus 268 seconds for the IKDC assessment (P < .0001), whereas shoulder patients' times were 61, 139, and 116 seconds for the PF-CAT, SST, and ASES evaluation, respectively (P < .0001). CONCLUSIONS: The PF-CAT showed a high correlation with IKDC scores and a moderately high correlation with ASES and SST outcomes. The PF-CAT takes significantly less time to complete and exhibits improved or similar floor and ceiling effects in comparison to IKDC, SST, and ASES scores. The PF-CAT can be used in evaluating sports medicine knee and shoulder patients. LEVEL OF EVIDENCE: Level III, cross-sectional study.


Asunto(s)
Traumatismos de la Rodilla/fisiopatología , Medición de Resultados Informados por el Paciente , Lesiones del Hombro/fisiopatología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Estudios Retrospectivos , Medicina Deportiva , Adulto Joven
16.
Macromol Rapid Commun ; 36(9): 852-7, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25823716

RESUMEN

A novel and robust route for the synthesis of a new amphiphilic brush copolymer, poly(glycidyl methacrylate)-graft-polyethylene glycol (PGMA-g-PEG), with high grafting densities of 97%-98% through a "grafting onto" method via carbon dioxide chemistry is reported. PGMA-g-PEG can self-assemble and form stable spherical core-shell micelles in aqueous solution. Besides, the obtained PGMA-g-PEG polymer contains hydroxyurethane structures as the junction sites between the PGMA backbone and PEG side chain, which can be used for further modification.


Asunto(s)
Dióxido de Carbono/química , Polietilenglicoles/química , Ácidos Polimetacrílicos/química
17.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 32(2): 480-4, 2015 Apr.
Artículo en Zh | MEDLINE | ID: mdl-26211276

RESUMEN

To serve as carriers of cells and bioactive molecules, three-dimensional scaffolds play a key role in bone defect repair. The chemical component and microstructure of the scaffold can affect the mechanical properties and seed cells. A variety of fabrication techniques have been used in producing scaffolds, some made random porous structure, some created well-designed structure using rapid prototyping methods, and others prepared bio-derived materials as scaffolds. However, scaffolds may vary in their inner structure, mechanical properties and repairing efficiency as well because of different manufacturing methods. In this review, we overview the main achievements concerning the effects of material and microstructure on the mechanical performance, seed cells and defect repair of bone scaffolds.


Asunto(s)
Huesos , Andamios del Tejido , Materiales Biocompatibles , Porosidad
18.
Biomed Microdevices ; 16(3): 487-97, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24627217

RESUMEN

Folic acid (or folate, FA) has attracted considerable attention for cancer therapy. As one small molecule, its receptor (folate receptor, FR) is significantly overexpressed on the surface of many human tumor cells compared with normal cells. In this work, physical and chemical coupled modification method, that is the combination of nanoimprinting technique and graft polymerization, was adopted to modify FA on nanopatterned polydimethylsiloxane (PDMS) surface for possible application in micro-nanofluidic cytology. The surface property of differently treated PDMS was characterized by FTIR, AFM and contact angle measurement. AO/PI double staining, cell counting and MTT method were performed to examine the potential influence of FA modified nanopatterned PDMS on human cervical carcinoma (HeLa) cell behavior. Both FA modification and nanostructure have positive effect on the growth and viability of HeLa cells. It is the first time that the small molecule-folic acid was used to immobilize on the surface of PDMS in order to improve its surface property.


Asunto(s)
Dimetilpolisiloxanos/química , Ácido Fólico/química , Técnicas Analíticas Microfluídicas/métodos , Nanoestructuras/química , Dimetilpolisiloxanos/farmacología , Células HeLa , Humanos , Propiedades de Superficie , Agua/química
19.
Nanomedicine ; 10(2): 371-80, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23969104

RESUMEN

A novel polyethylene glycol 400 (PEG400) mediated lipid nanoemulsion as drug-delivery carrier for paclitaxel (PTX) was successfully developed. The formulation comprised a PEG400 solution of the drug (25mg/mL) that would be mixed with commercially 20% lipid emulsion to form PTX-loaded nanoemulsion (1mg/mL) prior to use. This two-vial formulation of PTX-loaded lipid nanoemulsion (TPLE) could significantly reduce extraction of reticuloendothelial system (RES) organs and increase tumor uptake, and exhibited more potent antitumor efficacy on bearing A2780 or Bcap-37 tumor nude mice compared to conventional PTX-loaded lipid nanoemulsion (CPLE). TPLE did not cause haematolysis and intravenous irritation response yet, and showed the same cytotoxicity against HeLa cells as Taxol®, and its LD50 was 2.7-fold higher than that of Taxol®, suggesting its good safety and druggability. In addition, TPLE displayed distinctly faster release of PTX, a greater proportion of PTX in phospholipids layer and a smaller share in oil phase than CPLE. From the Clinical Editor: This study demonstrates the feasibility and potential advantage of a novel PEG400-mediated two-vial formulation of lipid nanoemulsion as drug carrier for PTX in clinical application for the cancer therapy. FROM THE CLINICAL EDITOR: This team of investigators convincingly demonstrates the feasibility and potential advantage of a PEG400-mediated two-vial formulation of lipid nanoemulsion as drug carrier for PTX in cancer therapy, documenting superior safety and faster release of PTX compared to commercially available formulations.


Asunto(s)
Portadores de Fármacos/química , Emulsiones/química , Paclitaxel/administración & dosificación , Polietilenglicoles/química , Animales , Línea Celular Tumoral , Femenino , Células HeLa , Humanos , Concentración 50 Inhibidora , Lípidos/química , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos ICR , Ratones Desnudos , Nanomedicina , Trasplante de Neoplasias , Neoplasias/terapia , Paclitaxel/química
20.
World J Microbiol Biotechnol ; 30(11): 2943-52, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25164957

RESUMEN

A novel endoglucanase gene was cloned from Rhizopus stolonifer and expressed in Escherichia coli, the gene product EG II (45 kDa) was assigned to Glycoside Hydrolase Family 45 (GH45), and its specific activity on phosphoric acid-swollen cellulose (PASC) was 48 IU/mg. To solve the problem of substrate accumulation in the cellulose hydrolysis and enhance the catalytic efficiency of endoglucanase, the eg2 gene was modified by site directed mutagenesis. Mutations generated by overlapping PCR have been proven to increase its catalytic activity on carboxymenthyl cellulose, microcrystalline cellulose (Avicel) and PASC, among which the mutant EG II-E containing all 6 mutations (N39S, V136D, T251G, D255G, P256S and E260D) peaked 121 IU/mg on PASC. The bioinformatic analysis showed that 2 key catalytic residues (D136 and D260) moved closer with the opening of a loop after mutagenesis, and a tunnel was formed by structural transformation. This structure was conducive for the substrate to access the active centre, and D136 played an indispensable role in the substrate recognition.


Asunto(s)
Celulasa/metabolismo , Proteínas Recombinantes/metabolismo , Rhizopus/enzimología , Secuencia de Aminoácidos , Dominio Catalítico , Celulasa/química , Celulasa/genética , Celulasa/aislamiento & purificación , Celulosa/metabolismo , Clonación Molecular , Biología Computacional , Análisis Mutacional de ADN , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Cinética , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Proteínas Mutantes/genética , Proteínas Mutantes/aislamiento & purificación , Proteínas Mutantes/metabolismo , Conformación Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Rhizopus/genética , Alineación de Secuencia
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