Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Micromachines (Basel) ; 15(6)2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38930643

RESUMO

A novel non-isothermal glass hot embossing system utilizes a silicon mold core coated with a three-dimensional carbide-bonded graphene (CBG) coating, which acts as a thin-film resistance heater. The temperature of the system significantly influences the electrical conductivity properties of silicon with a CBG coating. Through simulations and experiments, it has been established that the electrical conductivity of silicon with a CBG coating gradually increases at lower temperatures and rapidly rises as the temperature further increases. The CBG coating predominantly affects electrical conductivity until 400 °C, after which silicon becomes the dominant factor. Furthermore, the dimensions of CBG-coated silicon and the reduction of CBG coating also affect the rate and outcome of conductivity changes. These findings provide valuable insights for detecting CBG-coated silicon during the embossing process, improving efficiency, and predicting the mold core's service life, thus enhancing the accuracy of optical lens production.

2.
Mol Oncol ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38770553

RESUMO

Accumulation of abnormal chondroitin sulfate (CS) chains in breast cancer tissue is correlated with poor prognosis. However, the biological functions of these CS chains in cancer progression remain largely unknown, impeding the development of targeted treatment focused on CS. Previous studies identified chondroitin polymerizing factor (CHPF; also known as chondroitin sulfate synthase 2) is the critical enzyme regulating CS accumulation in breast cancer tissue. We then assessed the association between CHPF-associated proteoglycans (PGs) and signaling pathways in breast cancer datasets. The regulation between CHPF and syndecan 1 (SDC1) was examined at both the protein and RNA levels. Confocal microscopy and image flow cytometry were employed to quantify macropinocytosis. The effects of the 6-O-sulfated CS-binding peptide (C6S-p) on blocking CS functions were tested in vitro and in vivo. Results indicated that the expression of CHPF and SDC1 was tightly associated within primary breast cancer tissue, and high expression of both genes exacerbated patient prognosis. Transforming growth factor beta (TGF-ß) signaling was implicated in the regulation of CHPF and SDC1 in breast cancer cells. CHPF supported CS-SDC1 stabilization on the cell surface, modulating macropinocytotic activity in breast cancer cells under nutrient-deprived conditions. Furthermore, C6S-p demonstrated the ability to bind CS-SDC1, increase SDC1 degradation, suppress macropinocytosis of breast cancer cells, and inhibit tumor growth in vivo. Although other PGs may also be involved in CHPF-regulated breast cancer malignancy, this study provides the first evidence that a CS synthase participates in the regulation of macropinocytosis in cancer cells by supporting SDC1 expression on cancer cells.

3.
Int J Biol Macromol ; 261(Pt 2): 129748, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38281537

RESUMO

The advantages of physically modifying starch are evident: minimal environmental impact, no by-products, and straightforward control. The impact of dual modification on starch properties is contingent upon modification conditions and starch type. Herein, we subjected purple rice starch (PRS) to heat-moisture treatment (HMT, 110 °C, 4 h) with varying moisture content, ultrasound treatment (UT, 50 Hz, 30 min) with different ultrasonic power, and a combination of HMT and UT. Our findings reveal that UT following HMT dispersed starch granules initially aggregated by HMT and resulted in a rougher granule surface. Rheological analysis showcased a synergistic effect of HMT and UT, enhancing the fluidity of PRS and reinforcing its resistance to deformation in paste form. The absorbance ratio R1047/1015 indicates that increased moisture content during HMT and high ultrasound power for UT reduced the short-range order degree (1.69). However, the combined HMT-UT exhibited an increased R1047/1015 (1.38-1.64) compared to HMT alone (1.29-1.45), likely due to short-chain rearrangement. Notably, the A-type structure of PRS remained unaltered, but overall crystallinity significantly decreased (23.01 %-28.56 %), consistent with DSC results. In summary, physical modifications exerted significant effects on PRS, shedding light on the mechanisms governing the transformation of structural properties during HMT-UT.


Assuntos
Temperatura Alta , Oryza , Oryza/química , Amido/química , Fenômenos Químicos
4.
J Sci Food Agric ; 104(6): 3585-3593, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38150581

RESUMO

BACKGROUND: Modified polysaccharides have greatly expanded applications in comparison with native polysaccharides due to their improved compatibility and interactions with proteins and active compounds in food-related areas. Nonetheless, there is a noticeable dearth of research concerning the utilization of carboxymethyl starch (CMS) as a microcapsule wall material in food processing, despite its common use in pharmaceutical delivery. The development of an economical and safe embedding carrier using CMS and gelatin (GE) holds immense importance within the food-processing industry. In this work, the potential of innovative coacervates formed by the combination of GE and CMS as a reliable, stable, and biodegradable embedding carrier is evaluated by turbidity measurements, thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and rheological measurements. RESULTS: The results indicate that GE-CMS coacervates primarily resulted from electrostatic interactions and hydrogen bonding. The optimal coacervation was observed at pH 4.6 and with a GE/CMS blend ratio of 3:1 (w/w). However, the addition of NaCl reduced coacervation and made it less sensitive to temperature changes (35-55 °C). In comparison with individual GE or CMS, the coacervates exhibited higher thermal stability, as shown by TGA. X-ray diffraction analysis shows that the GE-CMS coacervates maintained an amorphous structure. Rheological testing reveals that the GE-CMS coacervates exhibited shear-thinning behavior and gel-like properties. CONCLUSION: Overall, attaining electroneutrality in the mixture boosts the formation of a denser structure and enhances rheological properties, leading to promising applications in food, biomaterials, cosmetics, and pharmaceutical products. © 2023 Society of Chemical Industry.


Assuntos
Gelatina , Polissacarídeos , Amido/análogos & derivados , Gelatina/química , Polissacarídeos/química , Proteínas
5.
Int J Biometeorol ; 67(5): 875-886, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37010576

RESUMO

As an important food crop in China, changes in suitable areas for rice planting are critical to agricultural production. In this study, the maximum entropy model (MaxEnt) was utilized to pick the main climatic factors affecting single-season rice planting distribution and project the potential changes under RCP4.5 and RCP8.5 scenarios. It was clear that rice planting distribution was significantly affected by annual total precipitation, the accumulated temperature during a period in which daily temperature was ≥ 10 °C, the moisture index, total precipitation during April-September, and continuous days during the period of daily temperature ≥ 18 °C, with their contribution being 97.6%. There was a continuous decrease in the area of good and high suitability for rice planting projected from 2021-2040 to 2061-2080, with a respective value ranging from 1.49 × 106 km2 to 0.93 × 106 km2 under the RCP4.5 scenario and from 1.42 × 106 km2 to 0.66 × 106 km2 under RCP8.5 scenarios. In 2081-2100, there was a bit increase in the area of good and high suitability under the RCP4.5 scenario. The most significant increases in good and high suitability were detected in Northeast China, while obvious decreases were demonstrated in the Yangtze River Basin which might be exposed to extreme temperature threat. The spatial potential planting center was characterized by the largest planting area in 25°N-37°N and 98°E-134°E. The north boundary and center of rice cultivation arose to 53.5°N and 37.52°N, respectively. These potential distributions for single-season rice under future climate change can provide a theoretical basis for optimizing rice planting layout, improving cultivation, and adjusting variety and management systems in response to climate change.


Assuntos
Oryza , Estações do Ano , Modelos Teóricos , Mudança Climática , China
6.
Int J Biol Macromol ; 181: 160-168, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33775756

RESUMO

Flexible electronic sensors composed of conductive material and flexible film have attracted increasing attention in decades due to its commercial, medical and scientific value. However, the poor interfacial bonding robustness between conductive materials and flexible film influences widely practical application of sensors. It is still a great challenge to fabricate a self-adhesive conductive film. Herein, we report a freestanding and self-adhesive bovine serum albumin/polypyrrole (BSA/PPy) hybrid film at the air/water interface. It is discovered that the PPy nanoparticles aggregate uniformly on the BSA film that is formed by amyloid-like BSA aggregation. The BSA/PPy film was integrated with polydimethylsiloxane (PDMS) film to fabricate flexible electronic sensors. The test indicates that the BSA/PPy film-based sensor could tolerate 500 cycles of bending without the resistance performance variation. The BSA/PPy film functions as a key mediator to dynamically tune the PPy conductance in response to external pressures and strains. The sensors exhibit ability for detecting tiny acoustic vibration, real-time human motion, physiological behavior and for differentiating various breathing pattern. Our strategy may open a pathway to readily construct flexible electronic sensors toward practical applications.


Assuntos
Adesivos/química , Eletrônica/instrumentação , Fisiologia/instrumentação , Polímeros/química , Pirróis/química , Soroalbumina Bovina/química , Processamento de Sinais Assistido por Computador , Animais , Bovinos , Concentração de Íons de Hidrogênio , Polimerização
7.
J Med Genet ; 58(9): 619-627, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32820032

RESUMO

BACKGROUND: Deafness-dystonia-optic neuronopathy (DDON) syndrome is a progressive X-linked recessive disorder characterised by deafness, dystonia, ataxia and reduced visual acuity. The causative gene deafness/dystonia protein 1 (DDP1)/translocase of the inner membrane 8A (TIMM8A) encodes a mitochondrial intermembrane space chaperon. The molecular mechanism of DDON remains unclear, and detailed information on animal models has not been reported yet. METHODS AND RESULTS: We characterized a family with DDON syndrome, in which the affected members carried a novel hemizygous variation in the DDP1 gene (NM_004085.3, c.82C>T, p.Q28X). We then generated a mouse line with the hemizygous mutation (p.I23fs49X) in the Timm8a1 gene using the clustered regularly interspaced short palindromic repeats /Cas9 technology. The deficient DDP1 protein was confirmed by western blot assay. Electron microscopic analysis of brain samples from the mutant mice indicated abnormal mitochondrial structure in several brain areas. However, Timm8a1I23fs49X/y mutation did not affect the import of mitochondria inner member protein Tim23 and outer member protein Tom40 as well as the biogenesis of the proteins in the mitochondrial oxidative phosphorylation system and the manganese superoxide dismutase (MnSOD / SOD-2). The male mice with Timm8a1I23fs49X/y mutant exhibited less weight gain, hearing impairment and cognitive deficit. CONCLUSION: Our study suggests that frameshift mutation of the Timm8a1 gene in mice leads to an abnormal mitochondrial structure in the brain, correlating with hearing and memory impairment. Taken together, we have successfully generated a mouse model bearing loss-of-function mutation in Timm8a1.


Assuntos
Encéfalo/metabolismo , Mutação da Fase de Leitura , Transtornos da Audição/genética , Transtornos da Memória/genética , Mitocôndrias/genética , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial/genética , Adulto , Alelos , Animais , Encéfalo/patologia , Análise Mutacional de DNA , Modelos Animais de Doenças , Eletroencefalografia , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Transtornos da Audição/diagnóstico , Humanos , Imuno-Histoquímica , Masculino , Transtornos da Memória/diagnóstico , Camundongos , Camundongos Knockout , Mitocôndrias/ultraestrutura , Linhagem , Fenótipo , Superóxido Dismutase/metabolismo
8.
J Alzheimers Dis ; 74(4): 1231-1242, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32144987

RESUMO

BACKGROUND: Accumulation of p25 is thought to be a causative risk factor for Alzheimer's disease (AD). As a cleaved product of p35, p25 binds to cyclin-dependent kinase 5 (Cdk5) and leads to the hyperactivity of Cdk5. Then, Cdk5/p25 phosphorylates many pathological substrates related to neurodegenerative diseases. p25 transgenic (Tg) mouse model recaptures some pathological changes of AD, including tau hyperphosphorylation, neurofibrillary tangles, neuroinflammation, and neuronal death, which can be prevented by transgenic expression of Cdk5 inhibitory peptide (CIP) before the insult of p25. OBJECTIVE: In the present study, we would like to know whether adeno-associated virus serotype-9 (AAV9)-mediated CIP can protect neurons after insult of p25 in p25Tg mice. METHODS: Administration of AAV9-CIP or control virus were delivered in the brain of p25Tg mice via intracerebroventricular infusions following the induction of p25. Western blotting, immunohistochemistry and immunofluorescence assessment, and animal behavioral evaluation were performed. RESULTS: Brain atrophy, neuronal death, tau phosphorylation and inflammation in the hippocampus, and cognitive decline were observed in p25Tg mice. Administration of CIP but not the control virus in p25Tg mice reduced levels of tau phosphorylation and inflammation in the hippocampus, which is correlated with inhibition of brain atrophy and neuronal apoptosis in the hippocampus, and improvement of cognitive decline. CONCLUSION: Our results provide further evidence that the neurotoxicity of p25 can be alleviated by CIP.


Assuntos
Doença de Alzheimer/metabolismo , Comportamento/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Doença de Alzheimer/etiologia , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Animais , Western Blotting , Modelos Animais de Doenças , Feminino , Imunofluorescência , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Masculino , Camundongos , Camundongos Transgênicos , Teste do Labirinto Aquático de Morris , Neurônios/metabolismo , Fosfotransferases/antagonistas & inibidores , Fosfotransferases/genética , Fosfotransferases/metabolismo
9.
World J Clin Cases ; 7(18): 2823-2830, 2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31616698

RESUMO

BACKGROUND: Diverse presentations of dens invaginatus (DI) and root canal treatment with an immature open apex often pose challenges to dentists. Adequate treatment planning for DI is the main reason for successful approach, i.e., we should consider the shape and depth of the concave folding, the condition of the original pulp, and the growth stage of the root formation. CASE SUMMARY: A 9-year-old girl complained of severe pain of the right maxillary incisor (tooth 12) when chewing for two weeks. Following clinical and radiographic examinations, Oehlers type III DI of tooth 12, with an immature open apical foramen and a symptomatic periapical pathosis, was diagnosed. Cone-beam computed tomography verified the specific spatial and stereoscopic data regarding the communication between the main root canal and pseudo root canal of the involved tooth. After removing the source of infection, a mineral trioxide aggregate was selected to fill and seal the pseudo root canal; additionally, pulp capping of the main canal was performed through the interconnections between the root canals in the middle segment to preserve pulp vitality and enable continual root formation and eventual root apex closure. CONCLUSION: We propose to conduct main root canal pulp capping for DI with communication between the main and pseudo root canals.

10.
Front Microbiol ; 10: 1993, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31551954

RESUMO

PURPOSE: The application of metagenomic next-generation sequencing (mNGS) in the diagnosis of tuberculous meningitis (TBM) remains poorly characterized. Here, we retrospectively analyzed data from patients with TBM who had taken both mNGS and conventional tests including culture of Mycobacterium tuberculosis (MTB), polymerase chain reaction (PCR) and acid-fast bacillus (AFB) stain, and the sensitivity and specificity of these methods were compared. METHODS: We retrospectively recruited TBM patients admitted to the hospital between December 2015 and October 2018. The first collection of cerebrospinal fluid (CSF) samples underwent both mNGS and conventional tests. In addition, patients with bacterial/cryptococcal meningitis or viral meningoencephalitis were mNGS positive controls, and a patient with auto-immune encephalitis was an mNGS negative control. RESULTS: Twenty three TBM patients were classified as 12 definite and 11 clinical diagnoses, which were based on clinical manifestations, pathogen evidence, CSF parameters, brain imaging, and treatment response. The mNGS method identified sequences of Mycobacterium tuberculosis complex (MBTC) from 18 samples (18/23, 78.26%). In patients with definite TBM, the sensitivity of mNGS, AFB, PCR, and culture to detect MTB in the first CSF samples were 66.67, 33.33, 25, and 8.33%, respectively. The specificity of each method was 100%. Among the four negative mNGS cases (4/23, 17.39%), three turned out positive by repeated AFB stain. The agreement of mNGS with the total of conventional methods was 44.44% (8/18). Combination of mNGS and conventional methods increased the detection rate to 95.65%. One patient was diagnosed as complex of TBM and cryptococcal meningitis, in which AFB stain and cryptococcal antigen enzyme immunoassay were positive and the DNA of Cryptococcus neoformans was detected by mNGS. CONCLUSION: Our study indicates that mNGS is an alternative method to detect the presence of mycobacterial DNA in CSF samples from patients with TBM and deserves to be applied as a front-line CSF test.

11.
J Alzheimers Dis ; 70(2): 573-585, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31256130

RESUMO

BACKGROUND: Under stress stimulation, p25 is generated by cleavage of p35 and acts as an activator of cyclin-dependent kinase 5 (Cdk5) like p35. Unlike Cdk5/p35, which is important for brain development, aberrant activity of Cdk5/p25 plays a pathological role in neurodegenerative diseases, such as Alzheimer's disease, by inducing hyperphosphorylation of downstream substrates related to pathological progression. A truncated fragment of the c-terminus of p35, the Cdk5 inhibitory peptide (CIP), selectively inhibits Cdk5/ p25 activity in cultured neurons and in CIP/p25 tetra-transgenic mice. OBJECTIVE: First, we aimed to establish a p25 overexpression adult mouse model, then to evaluate whether CIP delivered by adeno-associated virus serotype 9 (AAV9) can ameliorate neuronal toxicity induced by p25. METHODS: The p25 overexpression mouse model was established by intracerebroventricular (i.c.v.) injection of AAV8-GFP-p25 in 8-week-old mice. One month later, these mice were i.c.v. injected with AAV9-CIP-T2A-mCherry or AAV9 vector as control. Pathological and behavioral changes were assessed 3-months post-injection in all mice. RESULTS: The p25 overexpression mice displayed hyperphosphorylation of tau at multiple sites, activation of astrocytes, and elevated inflammatory factors, including IL-1 and TNF-α, which were significantly decreased by the administration of CIP. However, Aß deposition and microgliosis were not obvious in p25 overexpression mice. In addition, a significant learning decline and anxiety-like behavior were induced by p25 toxicity, and CIP treatment improved learning ability in p25 mice. CONCLUSION: AAV-mediated p25 overexpression mouse model is easy to construct to study p25-induced neuronal toxicity. Application of CIP after p25 insult reverses the pathological changes and behavioral abnormalities.


Assuntos
Encéfalo/metabolismo , Dependovirus , Proteínas do Tecido Nervoso/metabolismo , Fragmentos de Peptídeos/metabolismo , Fosfotransferases/biossíntese , Proteínas tau/metabolismo , Animais , Encéfalo/patologia , Dependovirus/genética , Expressão Gênica , Células HEK293 , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Injeções Intraventriculares , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação/fisiologia , Fosfotransferases/genética , Proteínas tau/antagonistas & inibidores
12.
PLoS One ; 11(6): e0157057, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27295213

RESUMO

With the increasing penetration of power electronic equipment in modern residential distribution systems, harmonics mitigation through the distributed generation (DG) interfacing converters has received significant attention. Among recently proposed methods, the so-called active resonance damper (ARD) and harmonic voltage compensator (HVC) based on voltage detection can effectively reduce the harmonic distortions in selected areas of distribution systems. However, it is found out that when traditional ARD algorithm is used to eliminate harmonic current injected by non-linear loads, its performance is constrained by stability problems and can at most eliminate half of the load harmonic currents. Thus, inspired by the duality between ARD and HVC, this paper presents a novel improved resistive active power filter (R-APF) algorithm based on integral-decoupling control. The design guideline for its parameters is then investigated through carefully analyzing the closed-loop poles' trajectory. Computer studies demonstrate that the proposed algorithm can effectively mitigate the load harmonic currents and its performance is much better than traditional ARD based on proportional control.


Assuntos
Fontes de Energia Elétrica/normas , Instalação Elétrica/normas , Equipamentos e Provisões Elétricas/normas , Eletricidade , Fenômenos Físicos , Algoritmos , Artefatos , Eletrônica/instrumentação , Eletrônica/métodos , Limite de Detecção , Software
13.
Di Yi Jun Yi Da Xue Xue Bao ; 24(12): 1388-90, 2004 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-15604065

RESUMO

OBJECTIVE: To estimate the clinical value of continuous renal replacement therapy (CRRT) in the treatment of severe acute renal failure (ARF) and identify the factors influencing the patients' prognosis. METHODS: The clinical characteristics, disease severity and prognosis were retrospectively studied in 116 patients with severe ARF undergoing CRRT from January, 1998 to May, 2004, in comparison with those in 102 such patients treated with intermittent hemodialysis (IHD). RESULTS: The mean score of Acute Physiology and Chronic Health Evaluation II (APACHE II) was 27.0+/-7.5 in patients receiving CRRT, of whom 56 (48%) had a score no less than 29, 36 (31%) between 24 to 29 and 24 (21%) less than 24. The mean APACHE II score was 21.9+/-5.2 in patients with IHD, and none of them had a score over 29, 44 (43%) had a score between 24 to 29 and 58 (57%) less than 24. The mean APACHE II score of CRRT group was significantly higher than that of IHD group (t=4.769, P=0.000), suggesting that most of the patients treated with CRRT were in critical condition. The patients' survival rate, however, did not differ significantly between the two groups, being 37% (43/116) in CRRT group and 48/ (49/102) in IHD group (X2=2.678, P=0.101 8). When only the patients with a score no less than 24 were compared, the survival rate of CRRT group was significantly higher than that of IHD group (24% vs 9%, X2=4.229, P=0.039 7), demonstrating better effect of CRRT than IHD in the management of critical ARF cases. In patients treated with CRRT, the patients in fatal cases had significantly older age, more critical condition (indicated by APACHE II score) and greater dependence on mechanical ventilation or vasoactive support than those who survived (P<0.05). CONCLUSIONS: CRRT is one of the effective methods for management of severe ARF patients, especially in those with critical conditions, with better effect than that of IHD. The prognosis of severe ARF patients treated with CRRT can be influenced by the patients' age and disease severity, and the need of vasoactive drugs or mechanical ventilation may help predict the patients' prognosis.


Assuntos
Injúria Renal Aguda/terapia , Terapia de Substituição Renal , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...