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1.
Biomacromolecules ; 23(4): 1789-1802, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35344361

RESUMO

The massive accumulation of plastic waste has caused a serious negative impact on the human living environment. Replacing traditional petroleum-based polymers with biobased and biodegradable poly(l-lactic acid) (PLLA) is considered an effective way to solve this problem. However, it is still a great challenge to manufacture PLLA-based composites with high thermal conductivity and excellent mechanical properties via tailoring the microstructures of the blend composites. In the present work, a melt extrusion-stretching method is utilized to fabricate biodegradable PLLA/poly(butylene adipate-co-butylene terephthalate)/carbon nanofiber (PLLA/PBAT/CNF) blend composites. It is found that the incorporation of the extensional flow field induces the formation of multioriented microstructures in the composites, including the oriented PLLA molecular chains, elongated PBAT dispersed phase, and oriented CNFs, which synergistically improve the thermal conductivity and mechanical properties of the blend composites. At a CNF content of 10 wt %, the in-plane thermal conductivity, tensile strength, and elongation at break of the blend composite reach 1.53 Wm-1 K-1, 66.8 MPa, and 56.5%, respectively, which increased by 31.9, 73.5, and 874.1% compared with those of the conventionally hot-compressed sample (1.16 Wm-1 K-1, 38.5 MPa, and 5.8%, respectively). The main mechanism for the improved thermal conductivity is that the multioriented structure promotes the formation of a CNF thermal conductive network in the composites. The strengthening mechanism is attributed to the orientation of both PLLA molecular chains and CNFs in the stretching direction, restricting the movement of PLLA molecular segments around CNFs, and the toughening mechanism is due to the transformation of PLLA molecular chains from low-energy gt conformers to high-energy gg conformers induced by extensional flow field. More interestingly, after the extrusion-stretched samples are annealed, the oriented PLLA molecular chains form oriented crystal structures such as extended-chain lamellae, common "Shish-kebabs," and hybrid Shish-kebabs, which further enhance the thermal conductivity and heat resistance of the samples. This work reveals the effects of the orientation of the matrix molecular chains and crystallites on the thermal conductivity and mechanical properties of composites and provides a new way to prepare high-performance PLLA-based composites with high thermal conductivity, excellent mechanical properties, and high heat resistance.


Assuntos
Nanofibras , Poliésteres , Humanos , Nanofibras/química , Poliésteres/química , Polímeros/química , Condutividade Térmica
2.
Yi Chuan ; 44(12): 1117-1127, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36927557

RESUMO

Anthocyanins are a class of important flavonoid compounds widely present in plants, and play important roles in plant growth, metabolism and stress responses. In the process of growth and development, anthocyanin renders the flowers and fruits of plants displaying rich colors, attracts insect pollination and animal feeding, thereby facilitating seed spreading and dissemination. In metabolic stress, anthocyanin can resist low temperature, drought, fungal infection, ultraviolet damage, insect pests and other stress-resistant processes. The anthocyanin biosynthesis is co-regulated by related structural genes as well as transcription factor genes. Recent studies have showed that the anthocyanin biosynthesis-related genes in plants are epigenetically regulated, thus affecting the synthesis of anthocyanin glycosides. Epigenetics is one of the hot topics in the field of biological sciences. In this review, we summarize the advances of epigenetic modifications in anthocyanin biosynthesis and the application of genome editing in epigenetics, thereby providing new ideas for flower color breeding improvement by epigenetic regulation.


Assuntos
Antocianinas , Epigênese Genética , Antocianinas/genética , Antocianinas/metabolismo , Melhoramento Vegetal , Plantas/metabolismo
3.
BMC Genomics ; 20(1): 776, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31653200

RESUMO

BACKGROUND: Aphid (Macrosiphoniella sanbourni) stress drastically influences the yield and quality of chrysanthemum, and grafting has been widely used to improve tolerance to biotic and abiotic stresses. However, the effect of grafting on the resistance of chrysanthemum to aphids remains unclear. Therefore, we used the RNA-Seq platform to perform a de novo transcriptome assembly to analyze the self-rooted grafted chrysanthemum (Chrysanthemum morifolium T. 'Hangbaiju') and the grafted Artermisia-chrysanthemum (grafted onto Artemisia scoparia W.) transcription response to aphid stress. RESULTS: The results showed that there were 1337 differentially expressed genes (DEGs), among which 680 were upregulated and 667 were downregulated, in the grafted Artemisia-chrysanthemum compared to the self-rooted grafted chrysanthemum. These genes were mainly involved in sucrose metabolism, the biosynthesis of secondary metabolites, the plant hormone signaling pathway and the plant-to-pathogen pathway. KEGG and GO enrichment analyses revealed the coordinated upregulation of these genes from numerous functional categories related to aphid stress responses. In addition, we determined the physiological indicators of chrysanthemum under aphid stress, and the results were consistent with the molecular sequencing results. All evidence indicated that grafting chrysanthemum onto A. scoparia W. upregulated aphid stress responses in chrysanthemum. CONCLUSION: In summary, our study presents a genome-wide transcript profile of the self-rooted grafted chrysanthemum and the grafted Artemisia-chrysanthemum and provides insights into the molecular mechanisms of C. morifolium T. in response to aphid infestation. These data will contribute to further studies of aphid tolerance and the exploration of new candidate genes for chrysanthemum molecular breeding.


Assuntos
Afídeos/fisiologia , Artemisia/citologia , Chrysanthemum/genética , Chrysanthemum/parasitologia , Perfilação da Expressão Gênica , Horticultura , Interações Hospedeiro-Parasita/genética , Animais , Chrysanthemum/citologia , Chrysanthemum/fisiologia , Anotação de Sequência Molecular , Estresse Fisiológico/genética
4.
Angew Chem Int Ed Engl ; 58(31): 10708-10712, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31125146

RESUMO

Considerable efforts have been devoted to achieving stable acene derivatives for electronic applications; however, the instability is still a major issue for such derivatives. To achieve higher stability with minimum structural change, CC units in the acenes were replaced with isoelectronic BN units to produce a novel BN-embedded tetrabenzopentacene (BNTBP). BNTBP, with a planar structure, is highly stable to air, moisture, light, and heat. Compared with its carbon analogue tetrabenzopentacene (TBP), BN embedment lowered the highest occupied molecular orbital (HOMO) energy level of BNTBP, changed the orbital distribution, and decreased the HOMO orbital coefficients at the central carbon atoms, which stabilize BNTBP molecules upon exposure to oxygen and sunlight. The single-crystal microribbons of BNTBP exhibited good performance in field-effect transistors (FETs). The high stability and good mobility of BNTBP indicates that BN incorporation is an effective approach to afford stable large-sized acenes with desired properties.

5.
Zhongguo Dang Dai Er Ke Za Zhi ; 19(2): 176-181, 2017 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-28202116

RESUMO

OBJECTIVE: To investigate the infections occurring in the induction period of childhood acute lymphoblastic leukemia (ALL), the pathogens of the infections, and drug resistance of isolated strains. METHODS: A retrospective analysis was performed for the clinical data of 130 children with newly-diagnosed childhood ALL. Infections occurring during the induction chemotherapy, pathogenic strains, and drug-resistance spectrum were analyzed. RESULTS: The incidence rate of clinical infection and/or microbial infection reached 76.2%. The lungs were the most common infection site (46.2%). The children with severe infection accounted for 52.3%, among whom 60 had pulmonary infection and/or 21 had sepsis. A total of 50 pathogenic strains were detected, which consisted of 29 bacterial strains and 21 fungal strains. Of all the children, 28.5% experienced infections caused by at least one microbe. Among the 29 bacterial strains, there were 19 (65.5%) Gram-negative bacteria and 10 (34.5%) Gram-positive bacteria. The most common Gram-negative bacteria were Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa, which were 100% sensitive to imipenem. The most common Gram-positive bacterium was Streptococcus viridans, which was 100% sensitive to vancomycin. The infections caused by fungi accounted for 16.2%, with Candida albicans as the most common fungus. Compared with those with non-severe infections, the children with severe infections had a significantly shorter time to the occurrence of agranulocytosis, a significantly longer duration of agranulocytosis, significantly higher incidence of fever and C-reactive protein (CRP) level, and a significantly longer length of hospital stay (P<0.05). CONCLUSIONS: Pulmonary infections are common in the induction period of childhood ALL. Gram-negative bacteria are the most common pathogenic bacteria. Severe infections can be controlled by carbapenems combined with vancomycin and antifungal agents.


Assuntos
Bactérias/isolamento & purificação , Infecções Bacterianas/microbiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Infecções Bacterianas/tratamento farmacológico , Criança , Pré-Escolar , Farmacorresistência Bacteriana , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 19(6): 652-657, 2017 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-28606231

RESUMO

OBJECTIVE: To explore the differences of NKX2.5 and TBX5 gene mutations between in vitro fertilization (IVF) children with congenital heart disease (CHD) and naturally conceived children with CHD. METHODS: Blood samples from 68 IVF children with CHD and 98 naturally conceived children with CHD were collected. The mutations in coding regions 1 and 2 of the NKX2.5 gene, and coding regions 4, 5, and 8 of the TBX5 gene were examined by polymerase chain reaction (PCR) and DNA sequencing. RESULTS: An A-to-G mutation at nucleotide 63 (c.63A>G) in coding region 1 of the NKX2.5 gene was found in both IVF and naturally conceived children with CHD. There were no significant differences in genotype and allele frequencies at c.63A>G locus of the NKX2.5 gene between the two groups. No mutations were detected in coding region 2 of the NKX2.5 gene and coding regions 4, 5 and 8 of the TBX5 gene. CONCLUSIONS: There is no difference in NKX2.5 and TBX5 gene mutations between IVF and naturally conceived children with CHD. Therefore, it is presumed that assisted reproductive technology may not lead to mutations in the NKX2.5 and TBX5 genes.


Assuntos
Fertilização in vitro , Cardiopatias Congênitas/genética , Proteína Homeobox Nkx-2.5/genética , Mutação , Proteínas com Domínio T/genética , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
7.
Zhongguo Dang Dai Er Ke Za Zhi ; 19(7): 741-747, 2017 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-28697824

RESUMO

OBJECTIVE: To observe the effects of initial doses and treatment timing of levothyroxine (L-T4) on the clinical efficacy in children with congenital hypothyroidism (CH). METHODS: This study included 98 children who had an abnormal level of thyroid stimulating hormone (TSH) in neonatal screening in four regions of Yunnan Province and who finally had a confirmed diagnosis of CH. They received treatment with L-T4 and were divided into standard dose group (10-15 µg/kg per day) and low dose group (<10 µg/kg per day) by the therapeutic dose of L-T4. Meanwhile, these patients were also classified into two treatment groups based on the starting time of L-T4 treatment, namely under 2 months old group and more than 2 months old group. The thyroid function and physical and neural development were examined before and after treatment. RESULTS: Compared with the low dose group, the standard dose group had a significantly lower TSH level and a significantly higher free thyroxine (FT4) level at 2 weeks after treatment (P<0.05). There were no significant differences in TSH and FT4 levels at other time points after treatment between the standard and low dose groups (P>0.05). The physical and neural development were not significantly different between the two dose groups before and at all time points after treatment (P>0.05). At all time points after treatment, the levels of TSH and FT4 and physical development were not significantly different between the different starting time groups (P>0.05). However, the Gesell score was significantly higher in the under 2 months old group than in the more than 2 months old group at all time points after treatment (P<0.05). CONCLUSIONS: The standard dose group has a better treatment outcome than the low dose group, whereas the symptoms of hyperthyroidism deserve close attention. The treatment timing is vital to the neurodevelopment of children with CH. Once diagnosed, the patients should receive treatments immediately.


Assuntos
Hipotireoidismo Congênito/tratamento farmacológico , Desenvolvimento Infantil , Hipotireoidismo Congênito/fisiopatologia , Feminino , Humanos , Recém-Nascido , Masculino , Sistema Nervoso/crescimento & desenvolvimento , Tireotropina/sangue , Tiroxina/sangue , Resultado do Tratamento
8.
Plant Dis ; 99(12): 1744-1750, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30699523

RESUMO

Field isolates of Alternaria alternata from peach were previously characterized for their sensitivity to succinate dehydrogenase inhibitor (SDHI) fungicides and the underlying molecular basis of resistance was determined. In the present study, we report that isolates resistant to the SDHI fungicide boscalid, regardless of genotype, were also resistant to pyraclostrobin and thiophanate-methyl. Resistance to pyraclostrobin was due to the G143A mutation in cytochrome b and resistance to thiophanate-methyl was due to 167Y in ß-tubulin. Representatives of the two most commonly isolated SDHI resistance genotypes, H277Y in sdh subunit B and H134R in sdh subunit C, as well as genotype D123E in sdh subunit D, were selected for fitness evaluations. Genotypes H277Y and H134R suffered no fitness penalties based on mycelial growth on potato dextrose agar, spore production in vitro, osmotic sensitivity, oxidative sensitivity, germination ability, or the ability to cause disease on peach fruit. Hypersensitivity to oxidative stress and weak sporulation was observed only in genotype D123E. No competitive advantage was detected for sensitive isolates over the course of five consecutive transfers on peach fruit when spores were mixed with genotypes H277Y or H134R. Results suggest that, in the absence of fungicide pressure, A. alternata isolates resistant to methyl benzimidazole carbamate, quinone outside inhibitor, and SDHI fungicides carrying the H277Y mutation in SDHB and the H134R mutation in SDHC may effectively compete with the boscalid-sensitive populations.

9.
Zhongguo Dang Dai Er Ke Za Zhi ; 17(4): 350-5, 2015 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-25919554

RESUMO

OBJECTIVE: To investigate the survival quality of infants conceived by in vitro fertilization (IVF) and to identify the factors that cause birth defects and neonatal complications in IVF infants. METHODS: The study included 150 IVF infants (IVF group) and 200 naturally conceived infants (control group). Indicators such as birth situation, gestational disease, birth defects, and neonatal complications were compared between groups. The influencing factors for birth defects and neonatal complications were analyzed by non-conditional logistic regression analysis. RESULTS: Compared with the control group, the IVF group had increased incidences of twin pregnancy and low birth weight (P<0.01) but decreased average birth weight (P<0.05). In the IVF group, the mother's age was elder, with higher incidence of cesarean section, premature rupture of membranes, and pregnancy complications, as compared with the control group (P<0.05). There was no significant difference in the incidence of birth defects between the two groups (P>0.05). The IVF group had higher incidence rates of low birth weight and neonatal scleroderma (P<0.05), with a longer hospital stay (P<0.01), as compared with the control group. The non-conditional logistic regression analysis indicated that IVF, prematurity, twin pregnancy, and pregnancy complications were risk factors for low birth weight (P<0.05). CONCLUSIONS: There is no significant difference in the incidence of birth defects between IVF and naturally conceived infants. However, IVF infants have higher incidences of twin pregnancy and low birth weight, with a longer hospital stay, as compared with naturally conceived infants. Natural conceiving, avoiding prematurity, twin pregnancy, and pregnancy complications will reduce the incidence of low birth weight.


Assuntos
Anormalidades Congênitas/epidemiologia , Fertilização in vitro/efeitos adversos , Recém-Nascido de Baixo Peso , Feminino , Humanos , Recém-Nascido , Modelos Logísticos , Masculino , Gravidez , Complicações na Gravidez/epidemiologia , Gravidez de Gêmeos/estatística & dados numéricos
10.
J Microbiol Methods ; 219: 106894, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38325717

RESUMO

The multidrug resistance of nontuberculous mycobacteria (NTM) poses a significant therapeutic challenge. Rapid and reliable drug susceptibility testing is urgently needed for evidence-based treatment decision, especially for macrolides. This study evaluated the utility of nucleotide matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (NMTMS) in detecting clarithromycin resistance. Sixty-four clinical isolates were identified to species by NMTMS, and mutations associated with clarithromycin resistance were detected. Twenty-three M. abscessus (MAB) isolates and 30 M. intracellulare isolates (including M. intracellulare alone and M. intracellulare in combination with other SGM species) were included for analysis. The predictive sensitivity of NMTMS in detecting clarithromycin resistance was 82.35% (95% CI, 56.57% to 96.20%), with an AUC of 0.89 (95% CI, 0.77 to 0.96) in all MAB and M. intracellulare (n = 53), and up to 93.33% (95% CI, 68.05% to 99.83%) in MAB alone (n = 23). The assay provides a rapid, high-throughput, and highly sensitive tool for detecting clarithromycin resistance in NTM, especially in MAB. Optimization of the panel is necessary to enhance diagnostic accuracy.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium tuberculosis , Humanos , Micobactérias não Tuberculosas , Claritromicina/farmacologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Testes de Sensibilidade Microbiana
11.
Phytochemistry ; 212: 113710, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37178942

RESUMO

Six undescribed C27-phytoecdysteroid derivatives, named superecdysones A-F, and ten known analogs were extracted from the whole plant of Dianthus superbus L. Their structures were identified by extensive spectroscopy, mass spectrometric methods, chemical transformations, chiral HPLC analysis, and the single-crystal X-ray diffraction analysis. Superecdysones A and B possess a tetrahydrofuran ring in the side chain and superecdysones C-E are rare phytoecdysones containing a (R)-lactic acid moiety, whereas superecdysone F is an uncommon B-ring-modified ecdysone. Notably, based on the variable temperature (from 333 K to 253 K) NMR experiments of superecdysone C, the missing carbon signals were visible at 253 K and assigned. The neuroinflammatory bioassay of all compounds were evaluated, and 22-acetyl-2-deoxyecdysone, 2-deoxy-20-hydroxyecdysone, 20-hydroxyecdysone, ecdysterone-22-O-benzoate, 20-hydroxyecdysone-20,22-O-R-ethylidene, and acetonide derivative 20-hydroxyecdysterone-20, 22-acetonide significantly suppressed the LPS-induced nitric oxide generation in microglia cells (BV-2), with IC50 values ranging from 6.9 to 23.0 µM. Structure-activity relationships were also discussed. Molecular docking simulations of the active compounds confirmed the possible mechanism of action against neuroinflammations. Furthermore, none compounds showed cytotoxicity against HepG2 and MCF-7. It is the first report about the occurrence and anti-neuroinflammatory activity of the phytoecdysteroids in the genus Dianthus. Our findings demonstrated that ecdysteroids may be used as potential anti-inflammatory drugs.


Assuntos
Dianthus , Dianthus/química , Ecdisterona/farmacologia , Simulação de Acoplamento Molecular , Doenças Neuroinflamatórias , Ecdisteroides/farmacologia
12.
J Sports Med Phys Fitness ; 62(11): 1568-1575, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35179334

RESUMO

BACKGROUND: The prevalence of essential hypertension increases consistently among middle-aged and older adults in China. Aims of this study are to explore the impact of Tai Chi and square dance, which are popular in China, on antihypertensive effects and cardiovascular disease risk factors in patients with essential hypertension. METHODS: Patients with essential hypertension were randomly assigned to either a Tai Chi group, a square dance group or a control group. Blood pressure, cardiorespiratory fitness, and cardiovascular disease risk factors were measured at baseline and at the end of the 12-week intervention. The duration and frequency of both intervention exercises were 60 minutes per session, and 5 sessions per week. RESULTS: A total of 144 participants (59.89±6.85 years, 34.72% male) completed the study. The repeated-measures analysis of variance demonstrated a significant effect of time on BMI, systolic and diastolic blood pressure, and cardiorespiratory fitness in patients with essential hypertension (P<0.05), whereas no significant effect was observed on waist-to-hip ratio and body fat percentage (P>0.05). Post hoc analyses showed that only intervention groups had significant differences in blood pressure and cardiorespiratory fitness compared to the control group, while Tai Chi had greater effect sizes than square dance. CONCLUSIONS: Both Tai Chi and square dance can promote cardiorespiratory fitness and reduce BMI and blood pressure among patients with essential hypertension, whereas there was no significant difference between the two exercises. However, both Tai Chi and square dance were ineffective in reducing some of the cardiovascular disease risk factors.


Assuntos
Doenças Cardiovasculares , Dança , Tai Chi Chuan , Pessoa de Meia-Idade , Humanos , Masculino , Idoso , Feminino , Hipertensão Essencial/terapia , Anti-Hipertensivos , Doenças Cardiovasculares/prevenção & controle , Fatores de Risco de Doenças Cardíacas
13.
Artigo em Inglês | MEDLINE | ID: mdl-35638614

RESUMO

Photothermoelectric (PTE) conversion can achieve the recovery of low-quality light or heat efficiently. Much effort has been devoted to the exploitation of the inorganic heterogeneous asynchronous (separate) PTE conversion system. Here, a full organic PTE film with a pseudobilayer architecture (PBA) according to the homogeneous synchronous (all-in-one) PTE conversion hypothesis was prepared via successive drop-casting a PEDOT:PSS/helical carbon nanotube (HCNT) mixture and PEDOT:PSS onto a vacuum ultraviolet treated substrate. Our results prove that the heptagon-pentagon pairs embedded in HCNTs promote a denser arrangement of the molecular chains of PEDOT, which enhances the crystallinity and affects the thermoelectric properties. The weak connection and hollow structure of HCNTs inhibit the dissipation of heat, and the zT value of the film reaches over 0.01. The PBA film shows better photothermal conversion performance than a neat PEDOT:PSS film and stably generates a temperature difference of over 25.68 °C without external cooling. A flexible PTE chip demo was manufactured, and the ideal open-circuit voltage (simulated via COMSOL) of that reaches over 1.5 mV under weak NIR stimulation (83.12 mW/cm2), which is the best value reported for an organic all-in-one PTE device, and the real maximum output power reaches 2.55 nW (166.01 mW/cm2). The chip has incredible ultraflexibility, and its inner resistance changes less than 1.42% after 10000 bending cycles and displays ultrahigh stability (similarity >90%) in a continuous periodic output. Our work fills the deficit of homogeneous synchronous PTE research for a PEDOT:PSS composite and is a preliminary attempt in an ultraflexible integrated all-in-one PTE chip design.

14.
ACS Appl Mater Interfaces ; 14(4): 6057-6070, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35042328

RESUMO

Multifunctional phase change materials (PCMs) are highly desirable for the thermal management of miniaturized and integrated electronic devices. However, the development of flexible PCMs possessing heat energy storage, shape memory, and adjustable electromagnetic interference (EMI) shielding properties under complex conditions remains a challenge. Herein, the multifunctional PCM composites were prepared by encapsulating poly(ethylene glycol) (PEG) into porous MXene/silver nanowire (AgNW) hybrid sponges by vacuum impregnation. Melamine foams (MFs) were chosen as a template to coat with MXene/AgNW (MA) to construct a continuous electrical/thermal conductive network. The MF@MA/PEG composites showed a high latent heat (141.3 J/g), high dimension retention ratio (96.8%), good electrical conductivity (75.3 S/m), and largely enhanced thermal conductivity (2.6 times of MF/PEG). Moreover, by triggering the phase change of the PEG, the sponges displayed a significant photoinduced shape memory function with a high shape fixation ratio (∼100%) and recovery ratio (∼100%). Interestingly, the EMI shielding effectiveness (SE) can be adjusted from 12.4 to 30.5 dB by a facile compression-recovery process based on shape memory properties. Furthermore, a finite element simulation was conducted to emphasize the advantage of the MF@MA/PEG composites in the thermal management of chips. Such flexible PCM composites with high latent heat storage, light-actuated shape memory, and adjustable EMI shielding functions exhibit great potential as smart thermal management materials in military and aerospace applications.

15.
ACS Appl Mater Interfaces ; 13(7): 8808-8822, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33565860

RESUMO

Helical carbon nanotube (HCNT) is a vital member of carbon nanomaterials, but little effort was devoted to explore its unique characteristics and applications during the past few decades. Here, we report an organic thermoelectric composite with an excellent photothermoelectric (PTE) effect by conformally wrapping polypyrrole (PPy) on the intricate surface of HCNTs, which have been confirmed to have remarkable near-infrared (NIR) photothermal conversion capability and ultralow heat transportation characteristics. The results indicate that with the increasing HCNT content, PPy shell thickness reduces and exhibits denser as well as partial orientation, while the inter-ring angle slowly decreases and the bipolaron becomes dominant in carrier composition gradually. Consequently, the Seebeck coefficient increases monotonically, whereas the electrical conductivity remains nearly invariant. The final composite combines the benign thermoelectric properties, excellent photothermal response performance, and the lowest thermal conductivity of the carbon-based thermoelectric composite yet reported (0.064 W m-1 K-1). A single strip NIR light-stimulated adjustable delay switch was designed and fabricated, with the open-circuit voltage and short-circuit current under a 400 mW cm-2 NIR-stimulated approach to 720 µV and 62 nA with the discrepancy of consecutive periodic output signals less than 4.2%, exhibiting incredible stability and reliability and demonstrating the highest output voltage of a single strip among the reported organic PTE composite at room temperature. Our work fills in a gap of HCNT research, which hitherto existed in the PTE and thermoelectric field.

16.
Carbohydr Polym ; 253: 117290, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33278953

RESUMO

The hybrid networks of cellulose nanocrystals (CNCs) and graphene nanoplatelets (GNPs) were constructed in polyethylene glycol (PEG) through the common solution compounding processing, in which GNPs provided the thermally conductive path while CNCs restricted the leakage of PEG during the phase transition. The results showed that CNCs greatly enhanced the shape stability of the composite phase change materials (PCMs) while thermal conductivity was still maintained at high level. At the contents of 8 wt% (CNCs) and 4 wt% (GNPs), the enthalpy of the composite PCM was 145.5 J/g, which was 88 % of pure PEG, and the thermal conductivity was 2.018±0.067 W/m K about 563.7 % higher than that of pure PEG. Furthermore, the composite PCMs exhibited outstanding light-thermal and electro-thermal conversion capabilities. Furthermore, the composite PCMs could be designed as the temperature stabilizing component exhibiting intelligent adaptive thermal management role, providing stable temperature condition for electronic devices in extreme environment.

17.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(2): 311-315, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33812392

RESUMO

OBJECTIVE: To investigate the clinical features and prognostic factors of acute lymphoblastic leukemia (ALL) children with P2RY8-CRLF2 gene rearrangement. METHODS: A total of 108 children with B-cell ALL (B-ALL) were diagnosed and systematically treated according to Chinese Children's Leukemia Group (CCLG) -ALL 2008 in our hospital from January 2016 to December 2016. The 108 patients were divided into two groups according to the result of mutiplex polymerase chain reaction: group with P2RY8-CRLF2 gene rearrangement and group without P2RY8-CRLF2 gene rearrangement. The ALL children with P2RY8-CRLF2 gene rearrangement were all treated by CCLG-ALL 2008 high-risk group (HR) regimens, and the ALL children in group without P2RY8-CRLF2 gene rearrangement received different intensity chemotherapy according to clinical risk classification. RESULTS: Five (4 male and 1 female) out of 108 patients with B-ALL had P2RY8-CRLF2 gene rearrangement. In the 5 B-ALL patients with P2RY8-CRLF2 gene rearrangement, the median age of the was 4 (2-6) years old and the median WBC count was 26.2 (2.46-525.1)×109/L. These patients presented different immunophenotype, including 3 cases of common B-ALL and 2 cases of pre B-ALL. Four patients carried a normal karyotype and 1 patient carried 46, XY, der (20) [22]/46, XY[2]. For the children with P2RY8-CRLF2 gene rearrangement, 1 patient (20%) could not achieve complete remission (CR), and minimal residual disease (MRD) of 2 patients (40%) was higher than 1% on day 33 of induction chemotherapy; while in group without P2RY8-CRLF2 gene rearrangement, all the patient achieved CR, and MRD in 6 patients (5.8%) was higher than 1% on day 33 of induction chemotherapy. The 3 year event-free survival (EFS) of ALL children in group with P2RY8-CRLF2 gene rearrangement was significantly lower than that in group without P2RY8-CRLF2 gene rearrangement (60.0%±21.9% vs 85.9%±3.9%) (P<0.05). CONCLUSION: The early treatment response and prognosis of ALL children with P2RY8-CRLF2 gene rearrangement are worse, and more effective protocol is needed for this subtype patients.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Rearranjo Gênico , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Prognóstico , Receptores de Citocinas/genética , Receptores Purinérgicos P2Y/genética
18.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(1): 49-55, 2021 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-33554796

RESUMO

OBJECTIVE: To investigate the clinical effect and safety of Chinese Children's Leukemia Group (CCLG)-ALL 2008 (high risk group) protocol in the treatment with childhood Mixed phenotype acute leukemia (MPAL). METHODS: The clinical data of 15 new diagnosed patients with MPAL treated in our hospital from January 2013 to December 2017 were retrospectively analyzed, and received CCLG-ALL 2008 (high risk group) protocol chemotherapy. RESULTS: One patient gave up treatment after diagnosed, and 14 children with MPAL after induction remission chemotherapy, 3 patients gave up, and 5 patients received consolidation chemotherapy, and 6 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT). The complete remission (CR) rate was 85.7% at d33 of induction remission chemotherapy. The serious adverse event and treatment-related mortality (TRM) rate was 71.4% and 14.3%, respectively. The recurrence rate was 21.4% and the median time of relapse was 12(9.7-18.4) months. Except for 4 patients who gave up treatment, the 5-year event-free survival (EFS) rate in the other 11 patients was (54.5±15.0)%. The 5 years EFS of 4 patients who received consolidation chemotherapy was significantly lower than the 6 patients who received allo-HSCT after CR (25.0%±21.7% vs 83.3%±15.2%, P=0.033). CONCLUSION: The CCLG-ALL2008 (for high-risk group) protocol in treatment of children with MPAL can get a high CR rate, but also with a high incidence of SAE. The patients received allo-HSCT after CR may have a good prognosis.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , Criança , Intervalo Livre de Doença , Humanos , Fenótipo , Prognóstico , Indução de Remissão , Estudos Retrospectivos
19.
J Cardiovasc Pharmacol ; 56(1): 45-52, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20351561

RESUMO

OBJECTIVES: Intermedin (IMD) is coexpressed in the heart with its receptor, which suggests that it may have localized actions as a modulator of cardiac function. The present study was designed to observe the interaction between IMD and cardiac hypertrophy and the possible mechanism involved in the antihypertrophic effects of IMD1-53 in cultured neonatal ventricular myocytes. METHODS: Myocyte hypertrophy was induced by treating the cells with angiotensin II, and the hypertrophic response was characterized by a significant increase in cell surface area, protein synthesis, and BNP mRNA expression. RESULTS: Our results showed that angiotensin II led to an obvious decrease in the production, secretion, and mRNA expression of IMD and increase receptor activity modifying proteins 1, 3 mRNA expression. Moreover, IMD1-53 inhibited the angiotensin II-induced hypertrophic response and the effects of IMD1-53 were similar to those of equivalent-dose adrenomedullin and could been blocked by H89. Otherwise, in our study, IMD1-53 resulted in dose-dependent increases of cAMP production in cardiomyocytes. CONCLUSIONS: Thus, IMD and its receptor system are involved in cardiac hypertrophy, and like adrenomedullin, IMD1-53 exerts an antihypertrophic effect on neonatal cardiomyocytes and the effect can be mediated by the cAMP/PKA pathway.


Assuntos
Adrenomedulina/metabolismo , Cardiomegalia/fisiopatologia , Miócitos Cardíacos/metabolismo , Neuropeptídeos/metabolismo , Adrenomedulina/administração & dosagem , Adrenomedulina/farmacologia , Angiotensina II/toxicidade , Animais , Animais Recém-Nascidos , Células Cultivadas , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ventrículos do Coração/citologia , Ventrículos do Coração/fisiopatologia , Miócitos Cardíacos/patologia , Peptídeo Natriurético Encefálico/genética , Neuropeptídeos/administração & dosagem , Neuropeptídeos/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar
20.
ACS Appl Mater Interfaces ; 12(23): 26444-26454, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32425040

RESUMO

Tailoring the distribution of nanoparticles and further constructing effective microcapacitors in polymer blends are important issues for developing high-performance polymer dielectric nanocomposites. The common method to control the selective localization of nanoparticles in an immiscible polymer blend is relatively difficult and it easily results in the accumulation of nanoparticles in one component, which usually leads to a dramatic increase of the dielectric loss in the nanocomposites. In this work, a novel strategy based on step-by-step crystallization has been proposed to tailor the refined distribution and dispersion of carbon nanotubes (CNTs) in a melt-miscible blend poly(butylene succinate)/poly(vinylidene fluoride) (PBS/PVDF) through the crystallization-induced phase separation and the engineered interfacial affinity between CNTs and polymer components to acquire high dielectric constant and low dielectric loss. The results reveal that PBS is excluded along the growth front of PVDF spherulites and locates in the margin areas of PVDF spherulites during the step-by-step crystallization process. Moreover, because of the higher interfacial interaction between CNTs and PBS, CNTs are located in the PBS-rich domain, resulting in a high concentration of CNTs in the interspherulites of PVDF. Thus, the dielectric constants of the nanocomposites are greatly improved by nearly 5-24 times compared with the nanocomposites achieved by quick cooling and, simultaneously, the dielectric loss of the nanocomposites is still maintained at a low level. This work shows that the step-by-step crystallization method can be used to fabricate the nanocomposites with a synergistic increase in the dielectric performance due to the formation of a refined microcapacitor assembly. To the best of our knowledge, this is the first report to show that the dielectric constant of the nanocomposites can be greatly enhanced just through the crystallization-optimized distribution and dispersion of CNTs in immiscible polymer blends, and it possibly gives a new technical route for the fabrication of advanced dielectric composites.

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