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1.
Science ; 367(6478): 667-671, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32029624

RESUMO

Robust, gas-impeding water-conduction nanochannels that can sieve water from small gas molecules such as hydrogen (H2), particularly at high temperature and pressure, are desirable for boosting many important reactions severely restricted by water (the major by-product) both thermodynamically and kinetically. Identifying and constructing such nanochannels into large-area separation membranes without introducing extra defects is challenging. We found that sodium ion (Na+)-gated water-conduction nanochannels could be created by assembling NaA zeolite crystals into a continuous, defect-free separation membrane through a rationally designed method. Highly efficient in situ water removal through water-conduction nanochannels led to a substantial increase in carbon dioxide (CO2) conversion and methanol yield in CO2 hydrogenation for methanol production.

2.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(2): 101-105, 2020 Feb 10.
Artigo em Chinês | MEDLINE | ID: mdl-32034731

RESUMO

OBJECTIVE: To explore the clinical feature, genetic variant and clinical outcome of patients with cblA-type methylmalonic acidemia (MMA). METHODS: Clinical manifestations, therapeutic schedule and prognosis of 12 patients with cblA type MMA were analyzed. MMAA gene variants were analyzed for all patients and their parents. RESULTS: Vomiting, dyspnea and drowsiness were the major clinical features of cblA-type MMA. Eleven patients were vitamin B12-responsive. After treatment, the blood level of propionylcarnitine, ratio of propionylcarnitine/acetylcarnitine, urine level of methylmalonic acid and methylcitric acid have decreased significantly (P< 0.05). Follow-up study showed that 8 patients (66.7%) had normal development, while the rest (33.3%) remained to have various level of mental or movement delay. Fourteen MMAA gene variants were detected, with c.365T>C (p.L122P) being the most common (29.2%). Six novel variants, including c.54delA (p.A19Hfs*43), c.275G>A (p.G92V), c.456delT (p.G153Vfs*8), c.667dupA (p.T223Nfs*4), c.1114C>T (p.Q372X) and c.1137_1138delCA (p.F379Lfs*27) were found. CONCLUSION: The main clinical manifestations of patients with cblA-type of MMA include vomiting, dyspnea and drowsiness. Most patients are vitamin B12-responsive. c.365T>C is a potential hot spot variant of MMAA gene in China.

3.
Sci Rep ; 10(1): 336, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941890

RESUMO

To increase the generation efficiency of the terahertz wave in the Y band, the idea of dual-reflector is introduced in the relativistic surface wave oscillator (SWO) with large oversized structures. The dual-reflector and the slow-wave structure (SWS) construct a resonator where the field strength of TM01 mode inside is intensively enhanced and then the efficiency is increased. The pre-modulation on electron beam caused by the reflector is also helpful in improving the output power. Meanwhile, the reflector can reduce the loss of negatively going electrons. Through the particle-in-cell (PIC) simulations, the optimized structure is tested to be stable and little power is transmitting back to the diode area. The output power reaches 138 MW in the perfectly electrical conductivity condition and the frequency is 337.7 GHz with a pure spectrum. The device's efficiency is increased from 10.7% to 16.2%, compared with the device without any reflectors. The performance of device with lossy material is also focused on. In the situation of copper device, the output power is about 41 MW under the same input conditions and the corresponding efficiency is about 4.8%.

4.
Huan Jing Ke Xue ; 41(1): 39-49, 2020 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854902

RESUMO

We report on successive haze weather that occurred in Shijiazhuang City, China, from December 30, 2018 to January 15, 2019. There were 12 days of heavy atmospheric pollution during this period, which primarily involved aerosol fine particulate matter (PM2.5). This study analyzes the causes of the pollution using component analysis and by assessing pollution evolution, spatial and temporal distributions of PM2.5, pollution sources, and meteorological factors. The results showed that PM2.5 was mainly composed of secondary inorganic ions (65.4%) that were mainly sourced from coal combustion (24.4%) and industrial sources (23.7%). The contributions of sulfate and secondary inorganic sources increased significantly with increasing pollution. Pollution was affected by unfavorable meteorological conditions (e.g., a low air mass) and by the particular local terrain, static stability, high humidity, and near-ground reverse temperatures from the south-southeast and west-southwest directions. Contaminants from primary sources including coal combustion, industry, and motor vehicle exhausts accumulated quickly in front of the Taihang Mountains. Secondary transformation of gaseous pollutants and increasing moisture absorption of particulate matter increased PM2.5 concentrations. Sulfate explosion also increased pollution. We recommend that as part of emergency responses to heavy pollution events, emissions reduction measures should be implemented to strengthen the control of SO2, NOx, and NH3 emission sources of secondary inorganic precursors, especially SO2 emission sources (i.e., coal etc.). We further propose a strengthen of the management of atmospheric emission sources in Xinle, Wuji, Shenze, Jinzhou, and Xingtang counties in the northeast of the city to reduce the impact of local transmission.

5.
Nat Commun ; 10(1): 5483, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792223

RESUMO

The development of facile and efficient polymerizations toward functional polymers with unique structures and attractive properties is of great academic and industrial significance. Here we develop a straightforward C-H-activated polyspiroannulation route to in situ generate photoresponsive spiro-polymers with complex structures. The palladium(II)-catalyzed stepwise polyspiroannulations of free naphthols and internal diynes proceed efficiently in dimethylsulfoxide at 120 °C without the constraint of apparent stoichiometric balance in monomers. A series of functional polymers with multisubstituted spiro-segments and absolute molecular weights of up to 39,000 are produced in high yields (up to 99%). The obtained spiro-polymers can be readily fabricated into different well-resolved fluorescent photopatterns with both turn-off and turn-on modes based on their photoinduced fluorescence change. Taking advantage of their photoresponsive refractive index, we successfully apply the polymer thin films in integrated silicon photonics techniques and achieve the permanent modification of resonance wavelengths of microring resonators by UV irradiation.

6.
Genes (Basel) ; 10(12)2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31805706

RESUMO

A complete mitogenome of Trachys auricollis is reported, and a mitogenome-based phylogenetic tree of Elateriformia with all protein-coding genes (PCGs), rRNAs, and tRNAs is presented for the first time. The complete mitochondrial genome of T. auricollis is 16,429 bp in size and contains 13 PCGs, two rRNA genes, 22 tRNA genes, and an A + T-rich region. The A + T content of the entire genome is approximately 71.1%, and the AT skew and GC skew are 0.10 and -0.20, respectively. According to the the nonsynonymous substitution rate to synonymous substitution rates (Ka/Ks) of all PCGs, the highest and lowest evolutionary rates were observed for atp8 and cox1, respectively, which is a common finding among animals. The start codons of all PCGs are the typical ATN. Ten PCGs have complete stop codons, but three have incomplete stop codons with T or TA. As calculated based on the relative synonymous codon usage (RSCU) values, UUA(L) is the codon with the highest frequency. Except for trnS1, all 22 tRNA genes exhibit typical cloverleaf structures. The A + T-rich region of T. auricollis is located between rrnS and the trnI-trnG-trnM gene cluster, with six 72-bp tandem repeats. Both maximum likelihood (ML) and Bayesian (BI) trees suggest that Buprestoidea is close to Byrrhoidea and that Buprestoidea and Byrrhoidea are sister groups of Elateroidea, but the position of Psephenidae is undetermined. The inclusion of tRNAs might help to resolve the phylogeny of Coleoptera.

7.
Sensors (Basel) ; 19(24)2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31835342

RESUMO

In this study, multispectral Light Detection and Ranging (LiDAR) data were utilized to improve delineation of individual tree crowns (ITC) as an important step in individual tree analysis. A framework to integrate spectral and height information for ITC delineation was proposed, and the multi-scale algorithm for treetop detection developed in one of our previous studies was improved. In addition, an advanced region-based segmentation method that used detected treetops as seeds was proposed for segmentation of individual crowns based on their spectral, contextual, and height information. The proposed methods were validated with data acquired using Teledyne Optech's Titan LiDAR sensor. The sensor was operated at three wavelengths (1550 nm, 1064 nm, and 532 nm) within a study area located in the city of Toronto, ON, Canada. The proposed method achieved 80% accuracy, compared with manual delineation of crowns, considering both matched and partially matched crowns, which was 12% higher than that obtained by the earlier marker-controlled watershed (MCW) segmentation technique. Furthermore, the results showed that the integration of spectral and height information improved ITC delineation using either the proposed framework or MCW segmentation, compared with using either spectral or height information individually.

8.
Sci Rep ; 9(1): 20218, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882938

RESUMO

The effects of low temperature gradient on dynamic mechanical properties of coal were examined through Split-Hopkinson Pressure Bar (SHPB) Dynamic Impact Experiment, the law of dynamic mechanical parameters of coal specimen changing from room temperature to negative temperature (25 °C, -5 °C, -10 °C, -15 °C, -20 °C, -30 °C, -40 °C) was analyzed, and the coal-rock stress-strain curve characteristics subject to the low temperature-impact load coupling effect was discussed. The law of the effects of different strain rates on the rock strength properties and the compressive deformation and failure was analyzed by studying the coal specimen at -15 °C. Moreover, the mechanical properties of coal specimen in saturated and dry conditions were compared, and the effects of water and water-ice phase transition on the strength properties of the corresponding coal specimen were analyzed.

9.
Zhongguo Yi Liao Qi Xie Za Zhi ; 43(6): 432-435, 2019 Nov 30.
Artigo em Chinês | MEDLINE | ID: mdl-31854530

RESUMO

Parkinson's Disease (PD) is a neurodegenerative disease that occurs in the middle-aged and elderly population and has dyskinesia as the main clinical symptom. Bradykinesia is a typical dyskinesia symptom of Parkinson's disease. The evaluation of bradykinesia based on wearable devices is an important support for individualized diagnosis and telemedicine. This paper focuses on the bradykinesia, expound the existing detection and evaluation techniques for wearable devices and data analysis methods. This paper also analyzes and discusses some current problems in the field and future research directions.


Assuntos
Hipocinesia , Doença de Parkinson , Telemedicina , Dispositivos Eletrônicos Vestíveis , Humanos
10.
Front Genet ; 10: 939, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681406

RESUMO

Cancer stem-like cells, possessing "stemness" properties, play crucial roles in progression, metastasis, and drug resistance in various cancers. Viral microRNAs (such as EBV-miR-BART7-3p), as exogenous regulators, have been discovered to regulate malignant progression of nasopharyngeal carcinoma (NPC), suggesting a possible role of viral microRNAs in imposing stemness. In this study, we found that EBV-miR-BART7-3p induce stemness of NPC cells. We firstly reported that EBV-miR-BART7-3p increased the percentage of side population cells, the development of tumor spheres, and the expression level of stemness markers in vitro. This viral microRNA also enhanced stem-like or cancer-initiating properties of NPC cells in vivo. Besides, we identified SMAD7 as a novel target gene of EBV-miR-BART7-3p in addition to PTEN gene we previously reported; this viral microRNA suppressed SMAD7, led to activation of TGF-ß signaling, and eventually enhanced the stemness of NPC cells. Silencing of SMAD7 resembled the effects generated by EBV-miR-BART7-3p in NPC cells. After reconstitution of SMAD7, EBV-miR-BART7-3p-expressing cells underwent a phenotypic reversion. EBV-positive NPC cells were used to enable experimental validation. Finally, we further discovered that EBV-miR-BART7-3p increased chemo-resistance of NPC in vitro and in vivo, supporting that EBV-miR-BART7-3 resulted in increased stemness of NPC cells and lead to drug resistance and cancer recurrence. Overall, this study uncovered a novel mechanism underlying viral microRNA-associated stemness of NPC cells. This viral microRNA and its associated cellular genes may be potential therapeutic targets for restraining chemo-resistance and recurrence of NPC.

11.
ACS Appl Mater Interfaces ; 11(47): 44118-44123, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31682102

RESUMO

Activity and immobilization of catalysts in liquid-phase reactions seem not to coexist. We report here the excellent activity of an MoOx nanoparticle (NP) catalyst for d-glucose epimerization to d-mannose and the electrical immobilization of NPs in a flow reaction. Prior to that, a green and one-pot method to synthesize the MoOx NPs (3.05 nm) via oxidizing metal Mo by hydrogen peroxide was presented. The NPs overwhelmed the reported catalysts including epimerase for d-glucose epimerization, originating from a strong interaction between the NPs and the reactant that was demonstrated by ex situ and in situ characterizations and theoretical calculations. The electrically charged feature of NPs inspired us to find a convenient way to "immobilize" them inside an activated carbon bed, and thereby, a flow reactor was assembled. The continuous epimerization was run under 24 V for 16 days with an almost unchanged activity, and only 3.2% of total Mo was lost.

12.
Int J Biol Macromol ; 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31730988

RESUMO

Some thermoduric food spoilage bacteria pose great threat to beverage industry. To tackle the challenge, hydroxypropyl trimethyl ammonium chloride chitosan (HTCC) grafted magnetic cellulose beads have been prepared via a dropping technology. Sodium periodate oxidation process was carried out to form dialdehyde functional groups on the regenerated cellulose beads mixed with maghemite nanoparticles. HTCC was anchored on the beads through Schiff base reaction. The structure and properties of HTCC anchored beads were evaluated by Fourier transform infrared (FTIR) spectra, field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Thermal stability of the beads was estimated by thermogravimetric analysis (TGA) and differential thermal gravity (DTG), and the decomposition temperature of the beads were around 200-300 °C. A long-term antibacterial activities of the beads against Alicyclobacillus acidoterrestris were confirmed caused by the covalent bond between HTCC and the beads. The biodegradable HTCC grafted cellulose beads may provide a novel approach for food safety management.

13.
Chem Commun (Camb) ; 55(85): 12801-12804, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31595277

RESUMO

Herein, for the first time, we find that the surface mass transport properties of catalysts play critical roles in determining the electrocatalytic NRR selectivity over the competitive HER in aqueous media on metallic Cu. In particular, by controlling the monolayer thickness of Cu nanoparticles with a minimum mass transport barrier, the faradaic efficiency (FE) of the NRR can be dramatically enhanced to 33% in the H-type cell test and even to 59% in a new-type Zn-N2 aqueous battery.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31557385

RESUMO

Pathogen infections and cancer are two major human health problems. Herein, we report the synthesis of an organic salt photosensitizer (PS), called 4TPA-BQ, by a one-step reaction. 4TPA-BQ presents aggregation-induced emission features. Owing to the aggregation-induced reactive oxygen species generated and a sufficiently small ΔEST , 4TPA-BQ shows a satisfactorily high 1 O2 generation efficiency of 97.8 %. In vitro and in vivo experiments confirmed that 4TPA-BQ exhibited potent photodynamic antibacterial performance against ampicillin-resistant Escherichia coli with good biocompatibility in a short time (15 minutes). When the incubation duration persisted long enough (12 hours), cancer cells were ablated efficiently, leaving normal cells essentially unaffected. This is the first reported time-dependent fluorescence-guided photodynamic therapy in one individual PS, which achieves ordered and multiple targeting simply by varying the external conditions. 4TPA-BQ reveals new design principles for the implementation of efficient PSs in clinical applications.

15.
Anal Chem ; 91(20): 12611-12614, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31558016

RESUMO

Lysosomal ß-N-acetylhexosaminidase (Hex) has been reported to possess unique physiological performances. Detection and visualization of Hex in lysosome will be favorable to reveal the basis of its functions. However, Hex-specific fluorescent probes are rarely reported. In this study, we reported the first lysosome-targeting Hex-lighting-up aggregation-induced emission (AIE)-active fluorescent probe (GlcNAc-TPE) with remarkably large Stokes shift and high sensitivity and selectivity. GlcNAc-TPE can selectively locate in lysosome and visualize endogenous Hex in live HCT116 cells and in live mice with high stability and good biocompatibility, providing a useful AIE probe for real-time visualization of Hex in live samples.

16.
Hereditas ; 156: 31, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31548836

RESUMO

Background: Cleidocranial dysplasia (CCD) is a rare autosomal dominant disorder mainly characterized by hypoplastic or absent clavicles, delayed closure of the fontanelles, multiple dental abnormalities, and short stature. Runt-related transcription factor 2 (RUNX2) gene variants can cause CCD, but are not identified in all CCD patients. Methods: In this study, we detected genetic variants in seven unrelated children with CCD by targeted high-throughput DNA sequencing or Sanger sequencing. Results: All patients carried a RUNX2 variant, totally including three novel pathogenic variants (c.722_725delTGTT, p.Leu241Serfs*8; c.231_232delTG, Ala78Glyfs*82; c.909C > G, p.Tyr303*), three reported pathogenic variants (c.577C > T, p.Arg193*; c.574G > A, p.Gly192Arg; c.673 C > T, p.Arg225Trp), one likely pathogenic variant (c.668G > T, p.Gly223Val). The analysis of the variant source showed that all variants were de novo except the two variants (c.909C > G, p.Tyr303*; c.668G > T, p.Gly223Val) inherited from the patient's father and mother with CCD respectively. Further bioinformatics analysis indicated that these variants could influence the structure of RUNX2 protein by changing the number of H-bonds or amino acids. The experimental result showed that the Gly223Val mutation made RUNX2 protein unable to quantitatively accumulate in the nucleus. Conclusions: The present study expands the pathogenic variant spectrum of RUNX2 gene, which will contribute to the diagnosis of CCD and better genetic counseling in the future.


Assuntos
Displasia Cleidocraniana/genética , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Núcleo Celular , Criança , Pré-Escolar , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Masculino , Mutação , Linhagem
17.
Appl Opt ; 58(25): 6891-6898, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31503659

RESUMO

Modal decomposition (MD) plays an increasingly important role in characterizing fiber beams. Several promising MD techniques have been proposed in literature, all of which are based on a common hypothesis that the modal field is coherently superposed by transverse modes. However, the partially coherent conditions have to be expected in general. In order to take account of this ordinary case, a novel MD scheme employing the Wigner distribution function (WDF) is introduced, which allows the decomposition of fiber beams without any restrictions regarding their degree of coherence. The four-dimensional (4D) WDF (two spatial and two spatial frequency dimensions) of the 2D fiber beam is reconstructed using the coded aperture technique. Based on the measured WDF and orthogonal property of transverse modes, the modal coefficients as well as the mutual modal degree of coherence will be determined unambiguously. The validity and reliability of the proposed approach are illustrated with numerical examples.

18.
J Genet Genomics ; 46(8): 397-404, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31471211

RESUMO

Understanding how gene expression is translated to phenotype is central to modern molecular biology, and the success is contingent on the intrinsic tractability of the specific traits under examination. However, an a priori estimate of trait tractability from the perspective of gene expression is unavailable. Motivated by the concept of entropy in a thermodynamic system, we here propose such an estimate (ST) by gauging the number (N) of expression states that underlie the same trait abnormality, with large ST corresponding to large N. By analyzing over 200 yeast morphological traits, we show that ST predicts the tractability of an expression-trait relationship. We further show that ST is ultimately determined by natural selection, which builds co-regulated gene modules to minimize possible expression states.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31401083

RESUMO

To identify the effects of poplar secondary metabolites on Lymantria dispar, six poplar secondary metabolites (i.e., caffeic acid, salicin, rutin, quercetin, flavone, and catechol) and three mixtures containing characteristic secondary metabolites in poplar were selected. Mixture 1 contained flavone and salicin, mixture 2 contained salicin, caffeic acid, and catechol, and mixture 3 contained flavone, catechol, and caffeic acid. Mixtures were added to artificial diets used to feed 2nd instar L. dispar larvae. The effects of different secondary metabolites on larval growth and development, antifeedant activity, nutrient utilization, and detoxifying enzymatic activity were investigated. Results revealed that there were different influences on L. dispar larvae. The maximum antifeedant rate of flavone was 87.58%. Larvae treated with mixture 2 had a significantly longer development time of 5.61 d with a survival rate of 38.75% for 15 d, which is lower than a single secondary metabolite. No L. dispar larvae survived on feeding diets containing flavone for 7 d. An increase in GST and P450 activities in larvae was significantly induced during the 72 h feeding on artificial diets containing experimental secondary metabolites. After treatment containing salicin and flavone for 24-72 h, P450 activity increased at first then decreased. These results provide a foundation for further investigation on the host selection and underlying adaptation mechanisms in L. dispar.

20.
Aging Dis ; 10(4): 784-792, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31440384

RESUMO

To evaluate the incidence of post-interventional contrast staining (PICS) in acute ischemic stroke (AIS) Chinese patients who were treated with endovascular thrombectomy (ET) and investigate potential association of PICS with functional outcome and intracerebral hemorrhage (ICH). This observational study was based on a single-center prospective registry study. AIS patients who underwent ET from January 2013 to February 2017 were recruited into this study. All patients had dual-energy CT (DECT) scan of the head at 12 to 24 hours post-ET. The primary outcome was the incidence of PICS. Secondary outcomes were total ICH, symptomatic ICH (sICH), 3-month functional outcome, and long-term functional outcome. One hundred and eighty patients were enrolled in this study. PICS was detected in 50 patients (28%) based on the post-interventional CT scan. We first used basic statistical analyses, showing that the incidence of both total ICH (60% vs. 25%, p<0.001) and sICH (18% vs. 8%, p=0.044) were higher in patients with PICS than those without, and fewer patients achieved no disability (mRS≤1) in the PICS group compared to the control group at both 3-month and long-term follow-up (p<0.01 each). However, multivariate regression analysis further revealed that PICS only increased total (adjusted odds ratio, 7.38; 95% confidence interval 1.66 to 32.9; p=0.009) but not sICH risk. Furthermore, the logistic regression analyses did not show statistical difference in good clinical outcomes or mortality between the two groups. PICS is a common phenomenon in Chinese AIS patients. It is associated with total ICH after ET, but it seems to have no effect on functional outcome and sICH. Further large-scale studies are warranted to validate these results.

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