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1.
Food Chem ; 303: 125386, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473454

RESUMO

The present work investigated the influences of ultrahigh pressure (UHP), ultrasound (US) and their combination (UHP-US) as pretreatments on properties of vacuum-freeze dried strawberry slices. During vacuum-freeze drying, drying duration and total energy consumption of UHP sample, US sample and UHP-US sample was decreased. After the UHP or US pretreatments, a* value (redness), antioxidative substances (total anthocyanin content, total flavonoid content, total phenolic content, diphenyl picrylhydrazyl (DPPH), hydroxyl (-OH) radical-scavenging assay), hardness and cross-section areas of matrix in the dried slices were significantly (P < 0.05) increased. Transverse relaxation times and peak area corresponding to free water in the pretreated samples were obviously decreased, indicating lower mobility in the pretreated samples. As compared with UHP or US individually, UHP in combination with US increased those parameters more pronouncedly. Therefore, UHP and US are promising techniques for the vacuum-freeze drying processing of strawberry products.

2.
J Nanosci Nanotechnol ; 20(4): 2138-2143, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492222

RESUMO

With the higher and higher application level of medical technology, more and more genetic diseases have been diagnosed. Nucleic acid, as an important genetic material, has been found to have important functions in the storage and transmission of the genetic information in the replication and synthesis of proteins. As the first step in nucleic acid detection experiments, nucleic acid extraction performance is associated with the purity of target nucleic acid samples, which is very important for the downstream steps. In this paper, we employed the magnetic bead for extracting nucleic acids based on the platform of large liquid handling workstation and designed a matching magnetic separation module. It was shown that the temperature control block designed in this paper has reliable stability, high accuracy by using the incremental PID algorithm, with the control accuracy up to ±0.5 °C, and the control stabilization time is about 90 s, which can satisfy the experimental requirements. Besides, the average magnetic bead transfer rate of this module was further verified by mimicking the manual magnetic bead nucleic acid extraction process. The results proved that the module has an excellent performance with the average magnetic bead transfer rate greater than 95% and the magnetic bead transfer rate in each well greater than 90%, which could be consistent with the experimental indictors of nucleic acid extraction.

3.
J Nanosci Nanotechnol ; 20(4): 2165-2170, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492225

RESUMO

The high-throughput nucleic acid detection system provides a good solution for detecting nucleic acids more safely, rapidly and accurately, which greatly improves the detection efficiency. Highthroughput nucleic acid detection mainly includes three steps: signal acquisition, signal amplification and signal processing. Therefore, obtaining the purified nucleic acid is the primary task of the nucleic acid detection, and the quality of the nucleic acid has a significant impact on results. In this paper, we employed the magnetic nanoparticle technology for extracting nucleic acids based on the platform of large liquid handling workstation and designed a matching vibrating module. The involved steps of core method, magnetic bead nucleic acid extraction technology, are mainly concerned with the cell lysis, nucleic acid binding, nucleic acid purification and magnetic particles elution. During the extraction process, specific temperature is required for the lysis and elution. It was shown that the temperature control part designed in this paper has the reliable stability, high accuracy by using the incremental proportion-integration-differentiation (PID) algorithm, with the control accuracy up to ±0.5 °C. The temperature regulating time is about 90 s, which can meet the experimental requirements. Besides, the vibrating uniformity of this module was further verified by protein concentration test, which proved that the module has the excellent performance and can be consistent with the experimental indictors of the nucleic acid extraction.

4.
J Nanosci Nanotechnol ; 20(3): 1332-1340, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492292

RESUMO

Nucleic acid aptamers are a kind of one-dimensional biological nanomaterials and have found many applications. This paper designed and implemented a polymerase chain reaction (PCR) amplification device with a reaction volume of 500 µL, which can be used for the amplification of nucleic acid aptamers of tumor cells in the aptamer selection. This device mainly includes a control module, a temperature measuring module, a PCR amplification tube, a metal tank module, a liquid crystal display (LCD) and operation module and a cooling module. The new PCR amplification chamber is matched with the designed metal tank to ensure the temperature uniformity of the PCR amplification solution. The control module based on the STM32F103RCT6 manages the workflow of the entire device. The PCR amplification chamber and PT100 sensors on the metal tank formed a closed-loop feedback system, and the incremental proportional-integral-derivative (PID) algorithm was used to achieve the precise temperature control. In addition, we introduced the Smith predictive compensation algorithm to solve the temperature hysteresis problem of the PCR amplification chamber. The experimental results showed that the PCR device can meet the requirements for the nucleic acid aptamer selection of tumor cells. The device can also be used in other experiments with large-volume PCR amplification.

5.
J Nanosci Nanotechnol ; 20(3): 1401-1408, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492300

RESUMO

In the automated high-throughput nucleic acid detection system, we need to grip and transfer consumables frequently when carrying out multichannel nucleic acid detection. In order to ensure the efficiency of experiments and solve problems of the deflection and drop when transferring microplates, we design a self-locking mechanical gripper which consists of a rotary positioning module and a gripping module. The absolute position encoder fixed on the top of the stepper motor can collect the position data of the mechanical gripper in real time and send them to the master control board based on STM32 for processing, which ensures the accuracy of the movement of the mechanical gripper. We used SolidWorks to build models of the mechanical gripper and different microplates, and we carried on finite element analysis of microplates to find the suitable gripping position. Through the force analysis, we obtained the pressure distribution and the deformation of different microplates, and defined the effective gripping areas, which is important to the grip and transfer of microplates.

6.
J Nanosci Nanotechnol ; 20(2): 692-700, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383064

RESUMO

Fluorescent bimetallic Au-Ag nanoclusters (Au-AgNCs) were found to exhibit oxidase-like activity and could catalyze the oxidation of 3,3',5,5' tetramethylbenzidine (TMB) to oxTMB. On the basis of this property, we assembled a fluorescent nanoplatform as a turn-on probe for sensing mercury (II) ions (Hg2+) through the inner-filter effect (IFE). Au-AgNCs and oxTMB were chosen as IFE absorber and fluorophore pair for the first time. In the absence of Hg2+, the Au-AgNCs absorption band well. Covered the fluorescence emission band of oxTMB, and as a result, the fluorescence of oxTMB was reduced. In the presence of Hg2+, Hg2+ was reduced to Hg0 by extra BSA in Au-AgNCs probe system and anchored on the surface of Au-AgNCs. The absorption intensity for Au-AgNCs then decreased at 418 nm, resulting in the recovery of fluorescence from oxTMB. The formed Au-Hg thin amalgam layer obviously enhanced the oxidase-like activity of Au-AgNCs as well as hindered the IFE activity between Au-AgNCs and oxTMB. Therefore, based on the Hg2+ stimulating oxidaselike properties of Au-AgNCs, a fluorometric assay for determination of Hg2+ was developed in this study. The proposed sensing strategy showed a linear range from 10 nM to 500 nM, with ultralow LOD of ~0.7 nM for Hg2+. Moreover, the detection probe system was stable over a wide pH range, making it able to be applied in complex sample systems. We have successfully demonstrated the detection of Hg2+ in tap water samples. The fluorescent assay reported here, for sensitive and selective determination of Hg2+, may find great application in multiple areas, such as environmental and pharmaceutical analysis.

7.
Int J Biol Macromol ; 140: 1167-1174, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31472208

RESUMO

Low-cost natural polymer lignin has been widely used to remove heavy metal ions from polluted water. But it still has some shortcomings, such as poor removal performance, and weak selective adsorption. Thus, in this study, the lignin prepared by Mannich reaction with black liquor was activated with triethylenetetramine (TETA) to achieve a novel adsorbent with high adsorption rates and a strong selectivity for specific oxygen-containing anions. The adsorption capacity of activated lignin (a-CL) on three oxygen-containing anions (i.e. As(V), P(V) and Cr(VI)) was investigated systematically. The adsorption mechanism of a-CL was elucidated theoretically by the density functional theory (DFT) method. Under the same conditions, the selectivity toward oxygen-containing anions by a-CL followed P(V) < Cr(VI) < As(V). Both FT-IR and DFT simulation results revealed that the hydrogen bond between HAsO42- and N dominated the remarkable selectivity of As (V), yielding a maximum adsorption capacity as high as 62.5 mg g-1. Moreover, the adsorption was very fast with a calculated large adsorption kinetic constant. The removal of As(V) reached 100% within 60 min. The As(V) adsorption kinetics and the adsorption isotherms followed the pseudo-second-order and the Langmuir model. This study provides a way for highly selecting removal of As(VI) from polluted water with the lignin.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31483591

RESUMO

Thermoelectric hetero nano region, as a new strategy, can effectively modulate the electrical and thermal transport properties. In this study, thermoelectric hetero nano region is explored to improve the thermoelectric performance for Bi0.46Sb1.54Te3 material at room temperature, and a high ZT of 1.45 at 325 K has been achieved. We introduce the thermoelectric hetero nano SnTe regions in Bi0.46Sb1.54Te3 matrix by mechanical alloying and spark plasma sintering technique, which decouples the relation between electrical and thermal transport properties. The improved electrical conductivity can be attributed to the increase in carrier concentration due to the increased point defects and Bi/SbTe antisite defects. Thermoelectric hetero nano regions effectively scatter the acoustic phonon and thus induce the low lattice thermal conductivity of 0.33 Wm-1K-1. Due to the synergistic modulation of electrical and thermal transport by the introduction of thermoelectric hetero nano region, a high ZT value of 1.45 is realized at 325 K.

9.
Int Heart J ; 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484870

RESUMO

Plaque erosion (PE) is a significant substrate of acute coronary thrombosis. An improved ability to distinguish plaque phenotype in vivo among patients with ST-segment elevation myocardial infarction (STEMI) is of considerable interest because of the potential to formulate tailored treatment. This study assessed the plaque features and screened the circulating microRNAs (miRNAs) characteristically expressed in patients with PE compared with those with plaque rupture (PR). An miRNA microarray profile was generated in an initial cohort of eight STEMI patients with PE and eight clinically matched subjects with PR to select the circulating miRNAs with significant differences. miRNAs of interest were validated in a prospective cohort, and the plaque characteristics of enrolled patients were assessed by optical coherence tomography (OCT). Thirty culprit lesions were classified as PE (32.6%) and 46 as PR (50%). The main component of PE was fibrotic tissue, whereas the chief component of PR was lipids (P < 0.001). Thirty-four miRNAs were differentially expressed between the two groups; we validated five candidates and found that only the level of circulating miR-3667-3p exhibited significant discriminatory power in predicting the presence of PE (AUC = 0.767; P < 0.001). Our results show that high levels of circulating miR-3667-3p are closely related to PE in STEMI patients, which provides further evidence for PE pathophysiology and potential tailor treatment strategies.

10.
J Biopharm Stat ; : 1-12, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31486705

RESUMO

Non-inferiority comparison between binary response rates of test and reference treatments is often performed in clinical studies. The most common approach to assess non-inferiority is to compare the difference between the estimated response rates with some margin. Previous methods use a variety of margins, including fixed margin, step-wise constant margin, and piece-wise smooth margin, where the latter two are functions of the reference response rate. The fixed margin approach assumes that the margin can be determined from historical trials with the consistent difference between the reference treatment and placebo, which may not be available. The step-wise constant margin approach suffers discontinuity in the power function which can cause trouble in sample size determination. Furthermore, many methods ignore the variability in margins dependent on the estimated reference response rate, leading to poor type I error control and power function approximation. In this study, we propose a variable margin approach to overcome the difficulties in fixed and step-wise constant margin approaches. We discuss several test statistics and evaluate their performance through simulation studies.

11.
Sensors (Basel) ; 19(17)2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31470563

RESUMO

A novel adaptive morphological attribute profile under object boundary constraint (AMAP-OBC) method is proposed in this study for automatic building extraction from high-resolution remote sensing (HRRS) images. By investigating the associated attributes in morphological attribute profiles (MAPs), the proposed method establishes corresponding relationships between AMAP-OBC and building characteristics in HRRS images. In the preprocessing step, the candidate object set is extracted by a group of rules for screening of non-building objects. Second, based on the proposed adaptive scale parameter extraction and object boundary constraint strategies, AMAP-OBC is conducted to obtain the initial building set. Finally, a further identification strategy with adaptive threshold combination is proposed to obtain the final building extraction results. Through experiments of multiple groups of HRRS images from different sensors, the proposed method shows outstanding performance in terms of automatic building extraction from diverse geographic objects in urban scenes.

12.
Eur J Pharm Sci ; : 105058, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31472255

RESUMO

The biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) is regulated by a phenomenon of quorum sensing (QS). With 5-hydroxyl-3,4-halogenated-5H-furan-2-ones as beginning, analogs bearing alkyl chains, vinyl bromide, or aromatic rings were designed and synthesized. The minimum inhibitory concentration (MIC) of the compounds against P. aeruginosa was assayed and the biofilm inhibition ratio was determined at different concentrations lower than the MIC. C-5 aromatic substituted furanones showed remarkable biofilm formation as well as inhibition of virulence factor production in P. aeruginosa. Fluorescence report analysis identified the QS regulatory mechanism of the most active compound 29. This study provides us a novel candidate for combating drug resistant bacteria strains by merely inhibiting biofilm formation. Without suppressing the regular life cycle of the bacteria, bacterial resistance mechanisms may not be activated.

13.
Sci Rep ; 9(1): 12847, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492915

RESUMO

Internal hernia (IH)-related surgical acute abdomen is not well understood because of the rarity of cases and underdiagnosis. This study was performed to further understand the clinicopathological features and multi-detector computed tomography (MDCT) findings of IH in cases confirmed by surgery. In all, 51 patients with a definite diagnosis of IH confirmed during surgical exploration from Feb. 2012 to Feb. 2018 in our hospital were included in this research. Medical records, including MDCT images and intra-operative findings, were collected retrospectively. In all, 39 and 12 cases were categorized as adhesive IH (76.5%) and non-adhesive IH (23.5%), respectively. Among the patients with adhesive IH, 73% had a history of abdominal or pelvic surgery. Additionally, the mesentery was the most common component of adhesive bands (64.1%). Congenital peritoneal abnormalities and gastrointestinal reconstruction were the main causes of non-adhesive IH.As a specific sign, the fat notch sign was much more common in adhesive IH than in non-adhesive IH (P = 0.023). Bowel wall thickening (P = 0.041), abnormal bowel wall enhancement (P = 0.006) and twisted bowels with the vessel swirl sign (P = 0.004) were indicators of bowel necrosis. Among all of the cases of IH, 34 (66.7%) were complicated by bowel necrosis, and 1 patient died. In conclusion, non-adhesive IH has different clinicopathological features and MDCT findings from those of adhesive IH. MDCT is a useful tool with high sensitivity for confirming IH and may help to guide the early treatment of IH.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31493074

RESUMO

Phosphogypsum (PG) accumulation occupies huge amounts of land resources and results in serious environmental risks. A new recycling product, the phosphogypsum embedded filler (PGEF) made with calcination-modified phosphogypsum, was developed. The preparation process, hydration mechanism of PG, basic physical performances, environmental safety, engineering application, and cost analysis of the PGEF were studied. The results showed that the stress performance and thermal insulation property of the products were satisfied. Environmental performance tests established their findings that the application of PGEF prepared with calcination-modified PG does not cause any secondary contamination. In addition, the cost of PGEF is far lesser than that of the same volume of reinforced concrete. PGEF prepared with calcination-modified PG has shown a perfect application in cast-in situ concrete hollow floor structure.

15.
J Am Chem Soc ; 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31487156

RESUMO

Insufficient brightness of fluorophores poses a major bottleneck for the advancement of super-resolution microscopes. Despite being widely used, many rhodamine dyes exhibit sub-optimal brightness due to the formation of twisted intramolecular charge transfer (TICT) upon photoexcitation. Herein, we have developed a new class of quaternary piperazine-substituted rhodamines with outstanding quantum yields (Φ = 0.93) and superior brightness (ε × Φ = 8.1 × 104 L·mol-1·cm-1), by utilizing the electronic inductive effect to prevent TICT. We have also successfully deployed these rhodamines in the super-resolution imaging of the microtubules of fixed cells and of the cell membrane and lysosomes of live cells. Finally, we demonstrated that this strategy was generalizable to other families of fluorophores, resulting in substantially increased quantum yields.

16.
Nat Commun ; 10(1): 4011, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488814

RESUMO

Ammonia represents a promising liquid fuel for hydrogen storage, but its large-scale application is limited by the need for precious metal ruthenium (Ru) as catalyst. Here we report on highly efficient ammonia decomposition using novel high-entropy alloy (HEA) catalysts made of earth abundant elements. Quinary CoMoFeNiCu nanoparticles are synthesized in a single solid-solution phase with robust control over the Co/Mo atomic ratio, including those ratios considered to be immiscible according to the Co-Mo bimetallic phase diagram. These HEA nanoparticles demonstrate substantially enhanced catalytic activity and stability for ammonia decomposition, with improvement factors achieving >20 versus Ru catalysts. Catalytic activity of HEA nanoparticles is robustly tunable by varying the Co/Mo ratio, allowing for the optimization of surface property to maximize the reactivity under different reaction conditions. Our work highlights the great potential of HEAs for catalyzing chemical transformation and energy conversion reactions.

17.
Med Sci Monit ; 25: 6736-6741, 2019 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-31494662

RESUMO

BACKGROUND This study assessed whether serum Golgi phosphoprotein 3 (GOLPH3) could be used as a biomarker for detecting bladder cancer. MATERIAL AND METHODS Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) assay were performed to measure GOLPH3 expression in serum and tissue samples, respectively, of bladder cancer patients. The associations of serum GOLPH3 expression with clinicopathological factors and the diagnostic accuracy were statistically evaluated using the chi-square test and receiver operating characteristic (ROC) curve analysis. RESULTS Compared with the healthy control group, serum GOLPH3 level was distinctly enhanced in bladder cancer patients (P<0.001). Moreover, compared to the non-malignant tissues, GOLPH3 showed positive expression in bladder cancer tissues. The abnormal GOLPH3 levels were tightly related to grade (P=0.018), tumor stage (P=0.000), lymph node status (P=0.030), and muscle invasion (P=0.012). ROC analysis showed that serum GOLPH3 exhibited a high diagnostic value to distinguish bladder cancer patients from healthy persons. The area under the ROC curve (AUC) was 0.948. The specificity and sensitivity were 92.5% and 83.8%, respectively. CONCLUSIONS GOLPH3 was highly expressed in bladder cancer patients and could be used as a diagnostic tool.

18.
Brain Imaging Behav ; 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31494823

RESUMO

Damage to the insular cortex has been shown to disrupt smoking behavior. However, whether smoking cessation outcomes are associated with abnormal functions of insula and its subregions remains unclear. In this study, we investigated the relationship between insular functions (interregional functional connectivity and regional activity) and treatment outcomes of cigarette smoking. Thirty treatment-seeking smokers were recruited into the treatment study and underwent magnetic resonance imaging (MRI) scans immediately before and after the treatment. Sixteen participants remained abstinent from smoking (quitters), while 14 relapsed to smoking (relapers). Changes in resting-state functional connectivity and fractional amplitude of low frequency fluctuation (fALFF) across groups and visits were assessed using repeated measures ANCOVA. Significant interaction effects were detected: 1) between the left anterior insula and left precuneus; and 2) between the right anterior insula and left precuneus and medial frontal gyrus. Post-hoc region-of-interest analyses in brain areas showing interaction effects indicated significantly increased functional connectivity after treatment compared with before treatment in quitters but opposite longitudinal changes in relapsers. However, no significant effects in fALFF were observed. These novel findings suggest that increased interregional functional connectivity of the anterior insula is associated with improved smoking cessation outcome: individuals with increased functional connectivity of the anterior insula during the treatment would more likely quit smoking successfully. These insular circuits may serve as therapeutic targets for more efficacious treatment of nicotine addiction.

19.
Nucleic Acids Res ; 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31495888

RESUMO

Interstrand crosslinks (ICLs) are highly toxic DNA lesions that are repaired via a complex process requiring the coordination of several DNA repair pathways. Defects in ICL repair result in Fanconi anemia, which is characterized by bone marrow failure, developmental abnormalities, and a high incidence of malignancies. SLX4, also known as FANCP, acts as a scaffold protein and coordinates multiple endonucleases that unhook ICLs, resolve homologous recombination intermediates, and perhaps remove unhooked ICLs. In this study, we explored the role of SLX4IP, a constitutive factor in the SLX4 complex, in ICL repair. We found that SLX4IP is a novel regulatory factor; its depletion sensitized cells to treatment with ICL-inducing agents and led to accumulation of cells in the G2/M phase. We further discovered that SLX4IP binds to SLX4 and XPF-ERCC1 simultaneously and that disruption of one interaction also disrupts the other. The binding of SLX4IP to both SLX4 and XPF-ERCC1 not only is vital for maintaining the stability of SLX4IP protein, but also promotes the interaction between SLX4 and XPF-ERCC1, especially after DNA damage. Collectively, these results demonstrate a new regulatory role for SLX4IP in maintaining an efficient SLX4-XPF-ERCC1 complex in ICL repair.

20.
Small ; : e1902729, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31497933

RESUMO

Solid-state electrolytes have recently attracted significant attention toward safe and high-energy lithium chemistries. In particular, polyethylene oxide (PEO)-based composite polymer electrolytes (CPEs) have shown outstanding mechanical flexibility and manufacturing feasibility. However, their limited ionic conductivity, poor electrochemical stability, and insufficient mechanical strength are yet to be addressed. In this work, a novel CPE supported by Li+ -containing SiO2 nanofibers is developed. The nanofibers are obtained via sol-gel electrospinning, during which lithium sulfate is in situ introduced into the nanofibers. The uniform doping of Li2 SO4 in SiO2 nanofibers increases the Li+ conductivity of SiO2 , generates mesopores on the surface of SiO2 nanofibers, and improves the wettability between SiO2 and PEO. As a result, the obtained SiO2 /Li2 SO4 /PEO CPE yields high Li+ conductivity (1.3 × 10-4 S cm-1 at 60 °C, ≈4.9 times the Li2 SO4 -free CPE) and electrochemical stability. Furthermore, the all-solid-state LiFePO4 -Li full cell demonstrates stable cycling with high capacities (over 80 mAh g-1 , 50 cycles at C/2 at 60 °C). The Li+ -containing mesoporous SiO2 nanofibers show great potential as the filler for CPEs. Similar methods can be used to incorporate Li salts into other filler materials for CPEs.

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