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1.
Angew Chem Int Ed Engl ; 60(49): 25758-25761, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34633732

RESUMO

High-quality MOF thin films with high orientation and controlled thickness are extremely desired for applications. However, they have been only successfully fabricated on flat substrates. Those MOF 2D thin films are limited by low exposed area and slow mass transport. To overcome these issues, MOF 3D thin films with good crystallinity, preferred orientation, and precisely controllable thickness in nanoscale were successfully prepared in a controllable layer-by-layer manner on nanowire array substrate for the first time. The as-prepared Cu-HHTP 3D thin film is superior to corresponding 2D thin films and showed one of the highest sensitivity, lowest LOD, and fastest response among all reported chemiresistive NH3 sensing materials at RT. This work provides a feasible approach to grow preferred-oriented 3D MOF thin film, offering new perspectives for constructing MOF-based heterostructures for advanced applications.

2.
Nanomaterials (Basel) ; 11(10)2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34685146

RESUMO

Herein, Bi4Ti3O12 (BIT) ferroelectric thin films were fabricated into Au/BIT/LaNiO3/Si structures to demonstrate their memristor properties. Repeatable and stable bipolar resistive switching (RS) characteristics of the device are first reported in this work. The switching ratio of the device annealed in air reached approximately 102 at 0.1 and -0.1 V. The RS performance was not significantly degraded after 100 consecutive cycles of testing. We also explored the factors affecting the RS behavior of the device. By investigating the RS characteristics of the devices annealed in O2, and in combination with XPS analysis, we found that the RS properties were closely related to the presence of oxygen vacancies. The devices annealed in air exhibited a markedly improved RS effect over those annealed in O2. According to the slope fitting, the conduction mechanism of the device was the ohmic conduction and space charge limited current (SCLC). This study is the first to successfully apply BIT ferroelectric films to the RS layers of memristors. Additionally, a theory of conductive filaments is proposed to adequately explain the relationship between RS behavior and oxygen vacancies, providing meaningful inspiration for designing high-quality resistive random access memory devices.

3.
Front Oncol ; 11: 667655, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568007

RESUMO

Purpose: To characterize clinical features and identify baseline prognostic factors for survival in young adults with advanced gastric cancer (YAAGC). Materials and Methods: A total of 220 young inpatients (age less than or equal to 40 years) with an initial diagnosis of advanced gastric cancer were retrospectively enrolled in this study. Results: Of a consecutive cohort of 220 patients with YAAGC, the median overall survival (OS) time was 16.3 months. One-year survival rate was 43.6% (95% CI: 36.5 to 50.7). In this cohort, a female (71.4%, n = 157) predominance and a number of patients with poorly differentiated tumors (95.9%, n = 211) were observed. In the univariate analysis, OS was significantly associated with neutrophil-lymphocyte ratio (NLR) (≥3.12), hypoproteinemia (<40 g/L), presence of peritoneal or bone metastases, and previous gastrectomy of primary tumor or radical gastrectomy. In multivariate Cox regression analysis, hypoproteinemia [hazard ratio (HR) 1.522, 95% CI 1.085 to 2.137, p = 0.015] and high NLR level (HR 1.446, 95% CI 1.022 to 2.047, p = 0.021) were two independent poor prognostic factors, while previous radical gastrectomy was associated with a favorable OS (HR 0.345, 95% CI 0.205 to 0.583, p = 0.000). A three-tier prognostic index was constructed dividing patients into good-, intermediate-, or poor-risk groups. Median OS for good-, intermediate-, and poor-risk groups was 36.43, 17.87, and 11.27 months, respectively. Conclusions: Three prognostic factors were identified, and a three-tier prognostic index was devised. The reported prognostic index may aid clinical decision-making, patient risk stratification, and planning of future clinical studies on YAAGC.

4.
J Dig Dis ; 22(9): 536-544, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34374198

RESUMO

OBJECTIVES: The accelerated shedding of extracellular domains of syndecan-4 (SDC4) is associated with central obesity and insulin resistance, while the association between serum SDC4 and nonalcoholic fatty liver disease (NAFLD) is unknown. We aimed to examine the association between SDC4 and NAFLD. METHODS: Adults undergoing a health examination from 1 June 2019 to 31 December 2019 were enrolled. A diagnosis of NAFLD was made with an abdominal ultrasound. Logistic regression models and the receiver operating characteristic (ROC) curves were used to evaluate the role of SDC4 in predicting NAFLD. RESULTS: In total, 533 eligible participants were finally enrolled, among them 157 (29.46%) had NAFLD. The proportion of patients with NAFLD increased with the increasing quartiles of serum SDC4. With the increase of serum SDC4 levels, metabolic features including waist circumference, serum triglyceride, total cholesterol, fasting blood glucose, fasting insulin and homeostasis model assessment of insulin resistance were significantly increased. SDC4 was an independent factor for NAFLD (odds ratio 1.963, 95% confidence interval [CI] 1.628-2.367, P < 0.001). The area under the ROC curve of SDC4 for predicting NAFLD was 0.934 (95% CI 0.910-0.959). The optimal cut-off value was 6.575 ng/mL at Youden's index of 0.767. SDC4 had the highest diagnostic sensitivity (84.1%), positive predictive value (82.5%), negative predictive value (93.3%) and positive likelihood ratio (11.356) among all the variables. CONCLUSIONS: Elevated serum SDC4 level is associated with metabolic disorders and the prevalence of NAFLD among general population. Serum SDC4 may serve as a biomarker of NAFLD.


Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Sindecana-4 , Adulto , Humanos , Fatores de Risco , Sindecana-4/sangue , Circunferência da Cintura
5.
Angew Chem Int Ed Engl ; 60(18): 9931-9935, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33591574

RESUMO

The construction of hydrophobic nanochannel with hydrophilic sites for bionic devices to proximally mimick real bio-system is still challenging. Taking the advantages of MOF chemistry, a highly oriented CuTCPP thin film has been successfully reconstructed with ultra-thin nanosheets to produce abundant two-dimensional interstitial hydrophobic nanochannels with hydrophilic sites. Different from the classical active-layer material with proton transport in bulk, CuTCPP thin film represents a new type of active-layer with proton transport in nanochannel for bionic proton field-effect transistor (H+ -FETs). The resultant device can reversibly modulate the proton transport by varying the voltage on its gate electrode. Meanwhile, it shows the highest proton mobility of ≈9.5×10-3  cm2 V-1 s-1 and highest on-off ratio of 4.1 among all of the reported H+ -FETs. Our result demonstrates a powerful material design strategy for proximally mimicking the structure and properties of bio-systems and constructing bionic electrical devices.

6.
ACS Sens ; 6(3): 1103-1110, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33576603

RESUMO

The urgent requirement of monitoring air pollution worldwide evokes intensive research interest in developing chemiresistive gas sensing techniques. To overcome the limits in sensitivity and selectivity of room temperature (RT) chemiresistive sensing materials, a new strategy using single-atom catalysts (SACs) via surface coordination is proposed. As a proof-of-concept, single Pd atoms on TiO2 (Pd1-TiO2) possess high efficiency in generating adsorbed O2- as well as high activity and selectivity in catalyzing CO oxidation at RT. As a result, Pd1-TiO2 shows record high sensitivity among the reported RT sensing materials, which is even comparable to those of the best materials working at high temperature. It also provides an approximately 1 order of magnitude lower limit of detection than the best CO sensing materials. Moreover, Pd1-TiO2 presents high selectivity toward 12 kinds of interference gases. This work not only paves a way to design high-performance RT gas sensing materials but also extends the application of SACs.


Assuntos
Gases , Catálise , Oxirredução , Temperatura
7.
Angew Chem Int Ed Engl ; 60(3): 1290-1297, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-32996683

RESUMO

Arranging ionic liquids (ILs) with long-range order can not only enhance their performance in a desired application, but can also help elucidate the vital between structure and properties. However, this is still a challenge and no example has been reported to date. Herein, we report a feasible strategy to achieve a crystalline IL via coordination self-assembly based reticular chemistry. IL1 MOF, was prepared by designing an IL bridging ligand and then connecting them with metal clusters. IL1 MOF has a unique structure, where the IL ligands are arranged on a long-range ordered framework but have a labile ionic center. This structure enables IL1 MOF to break through the typical limitation where the solid ILs have lower proton conductivity than their counterpart bulk ILs. IL1 MOF shows 2-4 orders of magnitude higher proton conductivity than its counterpart IL monomer across a wide temperature range. Moreover, by confining the IL within ultramicropores (<1 nm), IL1 MOF suppresses the liquid-solid phase transition temperatures to lower than -150 °C, allowing it to function with high conductivity in a subzero temperature range.

8.
Postgrad Med J ; 97(1143): 10-15, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33055193

RESUMO

BACKGROUND: Little is known about the impact of the provision of handheld point-of-care ultrasound (POCUS) devices on physical examination skills of medical students. METHODS: We describe an educational initiative that comprised a POCUS workshop followed by allocation of a POCUS device to medical students for use over the subsequent 8 weeks. They were encouraged to scan patients and correlate their physical examination findings. A mobile instant messaging group discussion platform was set to provide feedback from instructors. Physical examination skills were assessed by means of clinical examination. RESULTS: 210 final-year medical students from the University of Hong Kong participated in the programme. 46.3% completed the end of programme electronic survey: 74.6% enjoyed using the POCUS device, 50.0% found POCUS useful to validate physical examination findings and 47.7% agreed that POCUS increased their confidence with physical examination. 93.9% agreed that the programme should be incorporated into the medical curriculum and 81.9% would prefer keeping the device for longer time from 16 weeks (45.6%) to over 49 weeks (35.3%). Medical students who participated in the POCUS programme had a higher mean score for abdominal examination compared with those from the previous academic year with no POCUS programme (3.65±0.52 vs 3.21±0.80, p=0.014), but there was no statistically significant difference in their mean score for cardiovascular examination (3.62±0.64 vs 3.36±0.93, p=0.203). CONCLUSION: The POCUS programme that included provision of a personal handheld POCUS device improved students' attitude, confidence and ability to perform a physical examination.

9.
Postgrad Med J ; 2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33184131

RESUMO

BACKGROUND: Atrial fibrillation (AF) is associated with an increased risk of dementia. Little is known about the relationship of antithrombotic therapy and the risk of dementia in patients with AF without clinical stroke. METHOD: This was an observational study based on a hospital AF registry. Patients aged 65-85 years at the time of AF diagnosis were identified via the computerised database of the clinical management system. Patients with prior stroke or known cognitive dysfunction were excluded. The primary outcome was newly diagnosed dementia during the follow-up period. RESULTS: 3284 patients (mean age 76.4±5.3 years, 51.6% male) were included for analysis. The mean CHA2DS2-VASc score was 3.94±1.44. 18.5% patients were prescribed warfarin, 39.8% were prescribed aspirin and 41.7% were prescribed no antithrombotic therapy. After a mean follow-up of 3.6 years, 71 patients (2.2%) developed dementia, giving rise to an incidence of 0.61%/year. The incidence of dementia were 1.04%/year, 0.69%/year and 0.14%/year for patients on no therapy, aspirin and warfarin, respectively. Both univariate and multivariate analyses showed that age ≥75 years, female gender and high CHA2DS2-VASc score were associated with significantly higher risk of dementia; warfarin use was associated with significantly lower risk of dementia (HR: 0.14%, 95% CI 0.05 to 0.36, p<0.001). Patients on warfarin with time in therapeutic range (TTR) ≥65% had a non-significant trend towards a lower risk of dementia compared with those with TTR <65%. CONCLUSION: In elderly AF patients, warfarin therapy was associated with a significantly lower risk of new-onset dementia compared those with no therapy or aspirin.

10.
Artigo em Inglês | MEDLINE | ID: mdl-33201657

RESUMO

As an important method to further improve the storage density of resistive memory, multistage resistive switching devices have become an important research direction. However, no stable and controllable multistage resistive switching device has been prepared, and the working mechanism is still unclear. Here, a sandwich-structured device is simply prepared by spin coating, with the work layer is the Bi2FeCrO6 thin film. The device can realize bidirectional controllable multistage resistive switching behavior, the biggest on/off ratio is 104, and it can maintain stability without attenuation at 100 times slow loop and 104 times pulse cycle. The analyzes showed that the charged ions formed by defects in the device migrated under the action of an external electric field lead to the Schottky barrier height reversible changed. Which is the key to cause multistage resistive switching behavior. This work is the first report about the voltage control of bidirectional adjustable multistage resistive switching behavior in the Bi2FeCrO6 thin film. The principle of generation is analyzed, and important ideas and insights are provided for the preparation and treatment of related multistage resistive problems.

11.
Oxid Med Cell Longev ; 2020: 9815039, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33014281

RESUMO

Aims: We aimed to investigate whether LCZ696 protects against pathological cardiac hypertrophy by regulating the Sirt3/MnSOD pathway. Methods: In vivo, we established a transverse aortic constriction animal model to establish pressure overload-induced heart failure. Subsequently, the mice were given LCZ696 by oral gavage for 4 weeks. After that, the mice underwent transthoracic echocardiography before they were sacrificed. In vitro, we introduced phenylephrine to prime neonatal rat cardiomyocytes and small-interfering RNA to knock down Sirt3 expression. Results: Pathological hypertrophic stimuli caused cardiac hypertrophy and fibrosis and reduced the expression levels of Sirt3 and MnSOD. LCZ696 alleviated the accumulation of oxidative reactive oxygen species (ROS) and cardiomyocyte apoptosis. Furthermore, Sirt3 deficiency abolished the protective effect of LCZ696 on cardiomyocyte hypertrophy, indicating that LCZ696 induced the upregulation of MnSOD and phosphorylation of AMPK through a Sirt3-dependent pathway. Conclusions: LCZ696 may mitigate myocardium oxidative stress and apoptosis in pressure overload-induced heart failure by regulating the Sirt3/MnSOD pathway.


Assuntos
Aminobutiratos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Sirtuína 3/metabolismo , Superóxido Dismutase/metabolismo , Tetrazóis/farmacologia , Remodelação Ventricular/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Aminobutiratos/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Cardiomegalia/prevenção & controle , Combinação de Medicamentos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/patologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 3/antagonistas & inibidores , Sirtuína 3/genética , Tetrazóis/uso terapêutico , Regulação para Cima/efeitos dos fármacos
12.
Pathology ; 52(6): 676-685, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32768248

RESUMO

It is well-known that Epstein-Barr virus (EBV) is the promoter of cell tumourigenesis. We found that EBV is also a promoter of lymphoma cell dissemination, because we found the typical morphopathological phenomenon of cell adhesion, which confirmed that the adhesion of tumour cells was higher than that of normal cells. We also observed that tumour cells disrupted the dynamic pathological changes of vascular endothelial cells, and this made it clear that the rate of tumour cell metastasis was directly proportional to the degree of EBV infection. Furthermore, when we discovered exosomes, it was considered that this was associated with cancer stem cells, suggesting the formation of a microenvironment before tumour cell metastasis. In addition, competitive inhibition was found in cell adhesion, indicating the breakthrough point of preventing tumour cell metastasis, which has clinical reference value for tumour immunotherapy.


Assuntos
Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/fisiologia , Linfoma/virologia , Animais , Carcinogênese , Adesão Celular , Linhagem Celular Tumoral , Células Endoteliais/patologia , Infecções por Vírus Epstein-Barr/patologia , Exossomos/patologia , Humanos , Imuno-Histoquímica , Linfócitos/patologia , Linfoma/patologia , Camundongos , Camundongos SCID , Metástase Neoplásica , Microambiente Tumoral
13.
Int J Syst Evol Microbiol ; 70(5): 2981-2987, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375925

RESUMO

A novel nocardioform strain, CICC 11023T, was isolated from a tissue biopsy of neck lesions of a patient with primary cutaneous nocardiosis and characterized to establish its taxonomic position. The morphological, biochemical, physiological and chemotaxonomic properties of strain CICC 11023T were consistent with classification in the genus Nocardia. Whole-cell hydrolysates were rich in meso-diaminopimelic acid, galactose, arabinose and fructose. Mycolic acids were present. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid and two unidentified lipids, and the predominant menaquinone was cyclo MK-8 (H4, ω-cyclo). The main fatty acids (>5 %) were C18 : 0 10-methyl (TBSA), C16 : 0, summed feature 4 (C16 : 1 trans 9/C15 : 0 iso 2OH), C15 : 0 and C17 : 0 10-methyl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the isolate is most closely related (>98 % similarity) to the type strains Nocardia ninae OFN 02.72T, Nocardia iowensis UI 122540T and Nocardia alba YIM 30243T, and phylogenetic analysis of gyrB gene sequences showed similarity (89.1-92.2 %) to Nocardia vulneris NBRC 108936T, Nocardia brasiliensis IFM 0236T and Nocardia exalbida IFM 0803T. DNA-DNA hybridization results for strain CICC 11023T compared to Nocardia type strains ranged from 20.4 to 35.4 %. The genome of strain CICC 11023T was 8.78 Mbp with a G+C content of 67.4 mol% overall. The average nucleotide identity (ANI) values between strain CICC 11023T and N. alba YIM 30243T were low (OrthoANIu=77.47 %), and the ANI values between strain CICC 11023T and N. vulneris NBRC 108936 T were low (OrthoANIu=83.75 %). Consequently, strain CICC 11023T represents a novel Nocardia species on the basis of this polyphasic study, for which the name Nocardia colli sp. nov. is proposed. The type strain is CICC 11023T (=KCTC 39837T).


Assuntos
Nocardiose/microbiologia , Nocardia/classificação , Filogenia , Adulto , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Feminino , Humanos , Ácidos Micólicos/química , Pescoço , Nocardia/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
14.
Orthop Surg ; 12(3): 761-769, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32351029

RESUMO

OBJECTIVE: To investigate the incidence of cervical anomalies (CA), including cervical intraspinal neural axis abnormalities (CIINAA) and/or cervical osseous abnormalities (COA), and the clinical relevance in severe spinal deformities (SSD) at a single center. METHODS: A retrospective study of SSD admitted for spinal surgery from January 2003 to January 2015 was conducted at a single center. INCLUSION CRITERIA: patients who present with coronal Cobb over 90° (and/or sagittal cobb ≥90°); and patients with complete imaging and clinical data preoperatively. EXCLUSION CRITERIA: ankylosing spondylitis, adult onset scoliosis, scoliosis secondary to bone destruction. There were 108 SSD patients who fulfilled the criteria in this research (41 males and 67 females). The mean age of the patients was 18.1 ± 2.7 years (range, 10-45 years). The clinical and radiological data of these patients were reviewed to identify CA and to analyze the relationship between clinical and radiographic characteristics in the population of SSD. RESULTS: The major curves of scoliosis and segmental kyphosis were 109.1° ± 24.7° and 91.2° ± 29.1°. Cervical abnormalities were detected in 56 patients (51.85%) with 9 different CA, including 28 patients (25.9%) with 6 different COA, 21 patients (19.4%) with 3 different CIINAA, and 7 patients (6.5%) with a combination of COA and cervical intraspinal neural axis abnormalities (CINAA). Basilar invagination and Klippel-Feil syndrome were the most frequent COA. Syringomyelia was the most frequent CINAA. SSD with COA in upper vertebral levels (UVL) had a higher incidence of CINAA than those in subaxial vertebral levels (SVL) (P = 0.024) and SSD with multiple COA (mCOA) in UVL had a higher incidence of CINAA than those with single COA (sCOA) (P = 0.029). In the present study, 83.9% of the SSD with CA were asymptomatic. CONCLUSION: The incidence of CA in SSD was 51.85%, with most presenting with intact neurologic status. As the diversity of COA increased, we found a higher incidence of CINAA, especially in UVL.


Assuntos
Vértebras Cervicais/anormalidades , Vértebras Cervicais/diagnóstico por imagem , Malformações do Sistema Nervoso/diagnóstico por imagem , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Coluna Vertebral/diagnóstico por imagem , Adolescente , Adulto , Criança , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
15.
Chem Commun (Camb) ; 56(14): 2091-2094, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31960846

RESUMO

Silver chalcogenide wires are assembled for the first time using a linear fluorinated carboxylate ligand into a metal-organic framework (MOF) with multifunctional properties. Fluorinated ligands in the host framework endow the MOF with excellent hydrophobicity. More interestingly, it displays typical semiconductivity due to the ordered nanoarray of non-discrete helical (-Ag-S-)n chains.

16.
Biomed Pharmacother ; 121: 109552, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31715370

RESUMO

Rhodiola rosea L., a worldwide botanical adaptogen, has been confirmed to possess protective effects of inflammatory injury for many diseases, including cardiovascular diseases, neurodegenerative diseases, diabetes, sepsis, and cancer. This paper is to review the recent clinical and experimental researches about the anti-inflammatory effects and the related mechanisms of Rhodiola rosea L. extracts, preparations, and the active compounds. From the collected information reviewed, this paper will provide the theoretical basis for its clinical application, and provide the evidences or guidance for future studies and medicinal exploitations of Rhodiola rosea L.


Assuntos
Anti-Inflamatórios/farmacologia , Extratos Vegetais/farmacologia , Rhodiola/química , Animais , Anti-Inflamatórios/isolamento & purificação , Humanos , Inflamação/tratamento farmacológico , Inflamação/patologia
17.
Huan Jing Ke Xue ; 41(1): 242-252, 2020 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854925

RESUMO

Heavy metals are typical pollutants in the environment and microplastics are relatively newly recognized environmental pollutants, with their coexistence potentially compounding pollution and ecological risks. In this study, we investigate the contents and morphological characteristics of microplastics and heavy metals (Cu, Cd, Pb, Zn, and Cr) in the estuarine sediments of Poyang Lake and the Yangtze River as a means of exploring the relationship between them. The results showed that the abundance of microplastics ranged from 356 n·kg-1 to 1452 n·kg-1, with an average abundance of 982.33 n·kg-1 in the dry sediments. Microplastics were identified as being of three main types:fragments, fibers, and films, whereby fragments were the most dominant type found and accounted for 48.23% of the total microplastics in the sediments. The main color of microplastics in the sediments was chromatic, and the particle size of most microplastics was<1 mm. The major polymer components were polyethylene (PE), low density polyethylene (LDPE), and polyethylene (PP). Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) results indicated that the surfaces of microplastics were rough, porous, cracked, and torn, and that the five heavy metals were found on the surfaces of different microplastics. These heavy metals accumulated to different degrees in the estuarine sediments, and redundancy analysis indicated that environmental factors[including the total organic carbon (TOC), pH, electrical conductivity (EC), and sediment particle size] and the occurrence of microplastics all had significant (P<0.05) effects on the distribution of heavy metal concentrations in sediments. Variation partitioning analysis (VPA) showed that the contribution rates of environmental factors and microplastics to the bioavailability of heavy metals were 37.70% and 0.70% respectively, but the combined effect was 49.60%. We conclude that microplastics in sediments may act as carriers of heavy metals and activate their bioavailability, hence posing a potential threat to the ecological security of estuaries and wetlands.

18.
Nanomaterials (Basel) ; 9(12)2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31847505

RESUMO

Double perovskite Bi2NiMnO6 (BNMO) thin films grown on p-Si (100) substrates with LaNiO3 (LNO) buffer layers were fabricated using chemical solution deposition. The crystal structure, surface topography, surface chemical state, ferroelectric, and current-voltage characteristics of BNMO thin films were investigated. The results show that the nanocrystalline BNMO thin films on p-Si substrates without and with LNO buffer layer are monoclinic phase, which have antiferroelectric-like properties. The composition and chemical state of BNMO thin films were characterized by X-ray photoelectron spectroscopy. In the whole electrical property testing process, when the BNMO/p-Si heterojunction changed into a BNMO/LNO/p-Si heterojunction, the diode behavior of a single diode changing into two tail to tail diodes was observed. The conduction mechanism and temperature stability were also discussed.

19.
Huan Jing Ke Xue ; 40(6): 2639-2646, 2019 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854655

RESUMO

Microplastic pollution (plastics with particle sizes<5 mm) has become a serious problem. In this study, we sampled the surface water, sediment, and bird excrement from the shore, center of the lake, and active areas for birds in Baisha Lake, which is key habitat for migratory birds in the Poyang Lake wetlands. The microplastics were separated by flotation separation, and then, we analyzed the pollution characteristics of this area. The main results were as follows. ① There were significant differences in the abundance of microplastics in water and sediment at different sampling points in the study area. The average abundance of microplastics in water and sediment were 263.28 per·m-3 and 215.9 per·kg-1, respectively. The average abundance of microplastics in migratory bird feces was 4.93 per·g-1. ② There were four kinds of microplastics in the surface water in terms of the different morphologies of particles, namely, pellets, films, fragments, and fibers, among which pellets were the major type. The main colors of microplastics were red, yellow, green, blue, purple, black, and transparent. The rank in terms of the size of microplastics was follows: < 1 mm > 1-2 mm > 2-3 mm > 3-5 mm, and the abundance decreased with the increase of particle size. ③ There were also four kinds of microplastics with different morphologies in the sediment, namely, pellets, films, fragments, and fibers. The main colors of these microplastics were red, yellow, blue, purple, black, and transparent. Microplastic sizes on the shore of the lake and bird habitat were mainly < 1 mm, and 1-2 mm particles were mainly detected in the center of the lake. ④ There were four types of microplastics in the excrement of migratory birds, namely, pellets, films, fragments, and fibers. The colors of these microplastics were red, yellow, green, purple, and transparent, and the particle size was mainly < 1 mm. ⑤ There was no consistency in the types of microplastics in the water body, sediment, and bird droppings. However, the size distribution for water and bird excrement was consistent. The results indicate that Poyang Lake bird habitat is polluted by microplastics, and the birds are inevitably exposed to microplastics. This study warns that microplastics will be an emerging threat to migratory birds.


Assuntos
Aves , Lagos , Microplásticos/análise , Poluentes Químicos da Água/análise , Áreas Alagadas , Migração Animal , Animais , China , Ecossistema , Monitoramento Ambiental , Fezes , Sedimentos Geológicos
20.
Zhongguo Zhong Yao Za Zhi ; 44(20): 4317-4321, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31872615

RESUMO

In this paper,the design and development of sustained and controlled release preparations in traditional Chinese medicine( TCM) based on quality by design( QbD) was put forward,aiming at the current situation that the final product quality is affected by multiple factors during the development of sustained and controlled release preparations in TCM. The important development of sustained and controlled release preparations in western medicine in recent years was summarized. According to the complex process of TCM,the concept of QbD was proposed to design and develop sustained and controlled release preparations in TCM. QbD concept was used to analyze the complex factors affecting sustained and controlled release preparations in TCM,and determine the high risk factors affecting the quality of the final product. The high risk factors were controlled from the process to achieve the goal of quality control.This article could provide research ideas for the sustained and controlled release preparations with complex components in TCM,so as to promote the research and development of sustained and controlled release preparations in TCM.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Preparações de Ação Retardada , Controle de Qualidade
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