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1.
Enzyme Microb Technol ; 146: 109781, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33812562

RESUMO

L-amino acid ligases (Lals) are promising biocatalysts for the synthesis of dipeptides with special biological properties. However, their poor (or broad) substrate specificity limits their industrial applications. To address this problem, a molecular engineering method for Lals was developed to enhance their catalytic performance. Based on substrate channeling, entrances to the active site for different substrates were identified, and the "gate" located around the active site pocket, which plays an essential role in substrate recognition, was then engineered to facilitate acceptance of L-Gln. Two mutants (L110Y and N108F/L110Y) were discovered to display significantly increased catalytic activity toward L-Ala and L-Gln in the biosynthesis of Ala-Gln. The catalytic efficiency (kcat/ Km) of the L110Y and N108F/L110Y mutants was improved by 2.64-fold and 4.06-fold, respectively, compared with that of the wild type. N108F/L110Y was then further applied for batch production of Ala-Gln, which showed that the released Pi yield was 694.47 µM, which was an increase of approximately 21.4 %, and the yield of Ala-Gln was approximately 2.59 mM-1 L-1 mg-1. Collectively, these findings suggest the potential practical application of this method in the rational design of Lals for increased catalytic performance.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33896173

RESUMO

Two new sets of UiO-Zr metal-organic framework (MOF) bearing mixed linkers BDC-(SCH3)2 and BDC-(SOCH3)2 that have different band gaps and edges were prepared through post oxidation and direct methods, namely, UiO-66-(SCH3)2-xh (x = 4, 9, 12 oxidation hours) and UiO-66-(SOCH3)x(SCH3)2-x (x = 0, 0.4, 0.6, 2), respectively. These composites with stoichiometric components were fully characterized via proton nuclear magnetic resonance (1H NMR) spectroscopy, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectra, Brunauer-Emmett-Teller (BET), photo electrochemical measurements, and femtosecond transient absorption (fs-TA) spectroscopy. The structure, electronic property, and photoresponsive and catalytic ability as the functions of the molar ratio of linkers and the synthetic protocol were first investigated. The mixed-linker UiO-66-(SCH3)2-xh and UiO-66-(SOCH3)x(SCH3)2-x exhibited improved performances as compared to the UiO-66-(SCH3)2 and UiO-66-(SOCH3)2 possessing neat linkers only. Their photo response and catalytic activity varied with different linker ratios. For UiO-66-(SCH3)2-xh, the performance increased with the increasing linker BDC-(SOCH3)2 ratio upon oxidation but reached the highest as the BDC-(SOCH3)2 being of 24.4% in UiO-66-(SCH3)2-9h. In comparison, the best photocurrent (80.74 uA/cm-2) and the highest H2 generation rate (2018.8 µmol g-1 h-1) (λ > 400 nm) in UiO-66-(SCH3)2-9h are about twice those of UiO-66-(SOCH3)0.4(SCH3)1.6 obtained by direct synthesis, although the linker BDC-(SOCH3)2 ratio of those two composites is almost the same (24.4% vs 23.9%). Recorded shorter lifetime and higher charge separation efficiency of the former than those of the latter suggest the postsynthetic protocol as the efficient method for achieving the mixed-liner-MOF-based photocatalyst with high performance. A new type-II tailored homojunction is proposed in these mixed-linker MOFs for their efficient charge separation and improved activity.

3.
Zhongguo Gu Shang ; 34(1): 73-80, 2021 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-33666024

RESUMO

OBJECTIVE: To compare the clinical effects of three different methods of binding multi-fold rib graft, iliac bone graft and titanium mesh graft in tuberculosis of thoracic vertebra by approach of transverse rib process. METHODS: A hundred and seven patients with tuberculosis of thoracic vertebra received surgical treatment from January 2010 to December 2016 were retrospectively analyzed. The patients were divided into three groups according different methods of bone graft. The surgical approach of the transverse rib process was used in all 107 patients, after thoroughly remove the necrotic tissue of tuberculosis, three different bone grafts were used respectively including iliac bone graft (36 cases, group A), binding multi-fold rib graft (35 cases, group B), titanium mesh bone graft (36 cases, group C). Perioperative indexes, the time required for bone graft during operation, intraoperation blood loss, the loss rate of the anterior edge of the lesion, Cobb angle, postoperative bone graft fusion time, spinal nerve recovery and Oswestry Disability Index were compared among three groups. RESULTS: All the patients were followed up for 13 to 24 months, and the operation time required for bone graft was (23.2±4.1) min in group A, (23.8± 4.4)min in group B, and (25.5±4.2) min in group C, with no statistically significant difference among three groups (P>0.05). Intraoperative blood loss was (541.6±35.3) ml in group A, (546.8±27.8) ml in group B, and (540.1±34.5) ml in group C, withno statistically significant difference among three groups(P>0.05). Preoperative anterior vertebral height loss rate was (46.0± 3.1)% in group A, (46.4±3.3)% in group B, and (45.3±3.6)% in group B;at the final follow up, the loss rate of anterior vertebral height among three groups was (8.6±5.0)%, (8.1±4.2)%, (9.4±4.3)%, respectively. There were no statistically significant differences before operation and final follow-up among three groups (P>0.05). Preoperative Cobb angle was (35.1±4.8)° in group A, (35.2±4.5)° in group B and (35.2±4.5)° in group C, with no statistically significant difference among three groups (P>0.05);postoperative at 3 days, Cobb angle in three groups was (15.1±3.6)°, (15.3±3.1)° and (15.2±3.4)°, respectively, there was no statistically significant difference among three groups (P>0.05);at the final follow-up, the Cobb angle among three groups was (17.7±3.3)°, (17.9±3.9)°, (18.6±3.6)°, respectively, with no statistically significant difference among three groups (P>0.05). The time of bone graft fusion was (5.6±0.5) months in group A, (5.6±0.6) months in group B and (5.8±0.6)months in group C, with no statistically significant difference among three groups (P>0.05). Frankel classification at the final follow up, 4 cases were grade B, 7 cases were grade C, 10 cases were grade D, and 86 cases were grade E. Spinal nerve function in all three groups recovered to a certain extent after treatment, with no statistically significant difference among three groups (P> 0.05). Oswestry Disability Index at the final follow-up showed no statistically significant difference among three groups (P> 0.05). CONCLUSION: The approach of transverse rib process for debridement of lesions can effectively treat tuberculosis of thoracic vertebra by binding multi-fold rib graft, iliac bone graft and titanium mesh graft, but binding multi-fold rib graft can effectively avoid iliac bone donor complications, and is an effective alternative to iliac bone graft, which is worth popularizing.


Assuntos
Fusão Vertebral , Tuberculose da Coluna Vertebral , Transplante Ósseo , Humanos , Vértebras Lombares , Estudos Retrospectivos , Costelas/cirurgia , Telas Cirúrgicas , Vértebras Torácicas/cirurgia , Titânio , Resultado do Tratamento , Tuberculose da Coluna Vertebral/cirurgia
4.
Gut Microbes ; 13(1): 1-21, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33779497

RESUMO

Ferroptosis, a new type of cell death has been found to aggravate intestinal ischemia/reperfusion (I/R) injury. However, little is known about the changes of gut microbiota and metabolites in intestinal I/R and the role of gut microbiota metabolites on ferroptosis-induced intestinal I/R injury. This study aimed to establish a mouse intestinal I/R model and ileum organoid hypoxia/reoxygenation (H/R) model to explore the changes of the gut microbiota and metabolites during intestinal I/R and protective ability of capsiate (CAT) against ferroptosis-dependent intestinal I/R injury. Intestinal I/R induced disturbance of gut microbiota and significant changes in metabolites. We found that CAT is a metabolite of the gut microbiota and that CAT levels in the preoperative stool of patients undergoing cardiopulmonary bypass were negatively correlated with intestinal I/R injury. Furthermore, CAT reduced ferroptosis-dependent intestinal I/R injury in vivo and in vitro. However, the protective effects of CAT against ferroptosis-dependent intestinal I/R injury were abolished by RSL3, an inhibitor of glutathione peroxidase 4 (Gpx4), which is a negative regulator of ferroptosis. We also found that the ability of CAT to promote Gpx4 expression and inhibit ferroptosis-dependent intestinal I/R injury was abrogated by JNJ-17203212, an antagonist of transient receptor potential cation channel subfamily V member 1 (TRPV1). This study suggests that the gut microbiota metabolite CAT enhances Gpx4 expression and inhibits ferroptosis by activating TRPV1 in intestinal I/R injury, providing a potential avenue for the management of intestinal I/R injury.

5.
Phys Rev Lett ; 126(2): 021103, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33512196

RESUMO

We present the first search for gravitational waves from the coalescence of stellar mass and subsolar mass black holes with masses between 20-100 M_{⊙} and 0.01-1 M_{⊙}(10-10^{3} M_{J}), respectively. The observation of a single subsolar mass black hole would establish the existence of primordial black holes and a possible component of dark matter. We search the ∼164 day of public LIGO data from 2015-2017 when LIGO-Hanford and LIGO-Livingston were simultaneously observing. We find no significant candidate gravitational-wave signals. Using this nondetection, we place a 90% upper limit on the rate of 30-0.01 M_{⊙} and 30-0.1 M_{⊙} mergers at <1.2×10^{6} and <1.6×10^{4} Gpc^{-3} yr^{-1}, respectively. If we consider binary formation through direct gravitational-wave braking, this kind of merger would be exceedingly rare if only the lighter black hole were primordial in origin (<10^{-4} Gpc^{-3} yr^{-1}). If both black holes are primordial in origin, we constrain the contribution of 1(0.1)M_{⊙} black holes to dark matter to <0.3(3)%.

6.
Yi Chuan ; 43(1): 52-65, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33509774

RESUMO

Male sterility refers to the phenomenon that stamens cannot grow normally and produce viable pollen grains in plants. Hybrid seed production by taking advantage of the trait of male sterility is an effective and quick strategy to increase crop yield. Up to date, the yield of rice (Oryza sativa L.), maize (Zea mays L.), wheat (Triticum aestivum L.) and other crops has been greatly increased based on hybrid vigor utilization. Soybean (Glycine max (L.) Merr.) is a self-pollination species, artificial emasculation is not only time-consuming, but also labor-intensive and economically impracticable. So far, large scale hybrid breeding has not been performed in soybean due to the shortage of male sterile lines suitable for hybrid production. Therefore, it is urgent to identify a stable male sterile system for the rapid utilization of heterosis in soybean. In this review, we summarize the progress on the discovery of soybean genic male sterility (GMS) mutants and GMS genes. Combining with the investigation of GMS genes in Arabidopsis, rice and maize, we provide important insights into the identification and potential utilization of GMS genes in soybean in the perspective of reverse genetics.


Assuntos
Vigor Híbrido , Melhoramento Vegetal , Infertilidade das Plantas/genética , Soja/genética , Genética Reversa
7.
Food Chem ; 346: 128949, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33418419

RESUMO

The objective of this study was to investigate the antibacterial activity and potential mechanism of alkyl gallates against Escherichia coli and Staphylococcus aureus. Results show that the length of the alkyl chain plays a pivotal role in eliciting the activity and octyl gallate (OG) exerted excellent bactericidal activity through a multiple bactericidal mechanism. OG functions against both bacteria through damaging bacterial cell wall integrity, permeating into cells and then interacting with DNA, as well as disturbing the activity of the respiratory electron transport chain to induce a high-level toxic ROS (hydroxyl radicals) generation and up-regulation of the ROS genes. Also, electrospun nanofibers with OG have unique superiorities for maintaining the freshness of the icefish (4 °C). This research not only provides a more in-depth understanding of the interaction between OG and microorganisms but also highlights the great promise of using OG as a safe multi-functionalized food additive for food preservations.


Assuntos
Eletricidade , Escherichia coli/efeitos dos fármacos , Ácido Gálico/análogos & derivados , Nanofibras/química , Perciformes/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Ácido Gálico/química , Ácido Gálico/farmacologia , Testes de Sensibilidade Microbiana
8.
Org Lett ; 23(2): 607-611, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33377781

RESUMO

The Cu-catalyzed asymmetric carboboration of cyclohexadienone-tethered allenes has been achieved through regioselective ß-borylation of the allenes and subsequent conjugate addition to cyclohexadienones, affording cis-bicyclic frameworks with acceptable yields and high to excellent enantioselectivities. Further conjugate borylation of the carboboration products proved to be a favorable kinetic resolution process, which improved the overall enantioselectivity. Finally, one-pot preparation of highly enantioenriched tricyclo[5.2.2.04,9]undecanes was developed from the cyclohexadienone-tethered allenes through ß-borylation/1,4-addition and subsequent tandem oxidation/intramolecular aldol reaction.

9.
Bioelectrochemistry ; 138: 107717, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33333455

RESUMO

The slow kinetics of oxygen reduction reaction (ORR) and the formation of biofilm on cathode severely limited the performance of microbial fuel cells (MFCs). An efficient way to enhance the power-generation capacity and long-term stability of MFCs is to develop bifunctional catalyst by incorporating the efficient ORR catalysts with antibacterial ingredient. In this study, the Ag/Co-N-C nanosheets were designed and synthesized by decorating Ag nanoparticles (NPs) onto Co-N-C nanosheets, which were prepared from Zn/Co bimetallic metal-organic framework (ZIF-67/ZIF-8) precursor. The Zn/Co ratio, Ag doping amount and the calcination temperature of the precursor were systematically investigated. The optimum sample Ag/Co-N-C-30 revealed the excellent ORR performance with a half-wave potential of 0.80 V vs. RHE, which was slightly lower than that of Pt/C (0.82 V vs. RHE). The MFCs equipped with Ag/Co-N-C-30 cathode exhibited maximum power density of 548 ± 12.6 mW m-2 and superior durability even after 1600 h operation. Besides, the selective antimicrobial ability of Ag/Co-N-C-30 was further explored and the aerobic bacteria in cathode biofilm was found to be obviously inhibited by Ag/Co-N-C-30. The results suggested the Ag/Co-N-C nanosheets can serve as a promising cathode catalyst for practical applications of MFCs.

10.
J Mater Chem B ; 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33225338

RESUMO

It is an urgency to detect infectious pathogens or cancer biomarkers using rapid, simple, convenient and cost-effective methods in complex biological samples. Many existing approaches (traditional virus culture, ELISA or PCR) for the pathogen and biomarker assays face several challenges in the clinical applications that require lengthy time, sophisticated sample pre-treatment and expensive instruments. Due to the simple and rapid detection manner as well as no requirement of expensive equipment, many visual detection methods have been considered to resolve the aforementioned problems. Meanwhile, various new materials and colorimetric/fluorescent methods have been tried to construct new biosensors for infectious pathogens and biomarkers. However, the recent progress of these aspects is rarely reviewed, especially in terms of integration of new materials, microdevice and detection mechanism into the visual detection systems. Herein, we provide a broad field of view to discuss the recent progress in the visual detection of infectious pathogens and cancer biomarkers along with the detection mechanism, new materials, novel detection methods, special targets as well as multi-functional microdevices and systems. The novel visual approaches for the infectious pathogens and biomarkers, such as bioluminescence resonance energy transfer (BRET), metal-induced metallization and clustered regularly interspaced short palindromic repeats (CRISPR)-based biosensors, are discussed. Additionally, recent advancements in visual assays utilizing various new materials for proteins, nucleic acids, viruses, exosomes and small molecules are comprehensively reviewed. Future perspectives on the visual sensing systems for infectious pathogens and cancers are also proposed.

11.
Nat Commun ; 11(1): 4293, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855405

RESUMO

Among about 150 identified allenic natural products, the exocyclic allenes constitute a major subclass. Substantial efforts are devoted to the construction of axially chiral allenes, however, the strategies to prepare chiral exocyclic allenes are still rare. Herein, we show an efficient strategy for the asymmetric synthesis of chiral exocyclic allenes with the simultaneous control of axial and central chirality through copper(I)-catalyzed asymmetric intramolecular reductive coupling of 1,3-enynes to cyclohexadienones. This tandem reaction exhibits good functional group compatibility and the corresponding optically pure exocyclic allenes bearing cis-hydrobenzofuran, cis-hydroindole, and cis-hydroindene frameworks, are obtained with high yields (up to 99% yield), excellent diastereoselectivities (generally >20:1 dr) and enantioselectivities (mostly >99% ee). Furthermore, a gram-scale experiment and several synthetic transformations of the chiral exocyclic allenes are also presented.

12.
Curr Med Sci ; 40(3): 407-421, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32681246

RESUMO

Fluorescent nanoparticles have good chemical stability and photostability, controllable optical properties and larger stokes shift. In light of their designability and functionability, the fluorescent nanoparticles are widely used as the fluorescent probes for diverse applications. To enhance the sensitivity and selectivity, the combination of the fluorescent nanoparticles with the molecularly imprinted polymer, i.e. molecularly imprinted fluorescent nanoparticles (MIFN), was an effective way. The sensor based on MIFN (the MIFN sensor) could be more compatible with the complex sample matrix, which was especially widely adopted in medical and biological analysis. In this mini-review, the construction method, detective mechanism and types of MIFN sensors are elaborated. The current applications of MIFN sensors in pharmaceutical analysis, including pesticides/herbicide, veterinary drugs/drugs residues and human related proteins, are highlighted based on the literature in the recent three years. Finally, the research prospect and development trend of the MIFN sensor are forecasted.

13.
Front Oncol ; 10: 680, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547939

RESUMO

Background: Early-stage diagnosis and treatment can improve survival rates of liver cancer patients. Dynamic contrast-enhanced MRI provides the most comprehensive information for differential diagnosis of liver tumors. However, MRI diagnosis is affected by subjective experience, so deep learning may supply a new diagnostic strategy. We used convolutional neural networks (CNNs) to develop a deep learning system (DLS) to classify liver tumors based on enhanced MR images, unenhanced MR images, and clinical data including text and laboratory test results. Methods: Using data from 1,210 patients with liver tumors (N = 31,608 images), we trained CNNs to get seven-way classifiers, binary classifiers, and three-way malignancy-classifiers (Model A-Model G). Models were validated in an external independent extended cohort of 201 patients (N = 6,816 images). The area under receiver operating characteristic (ROC) curve (AUC) were compared across different models. We also compared the sensitivity and specificity of models with the performance of three experienced radiologists. Results: Deep learning achieves a performance on par with three experienced radiologists on classifying liver tumors in seven categories. Using only unenhanced images, CNN performs well in distinguishing malignant from benign liver tumors (AUC, 0.946; 95% CI 0.914-0.979 vs. 0.951; 0.919-0.982, P = 0.664). New CNN combining unenhanced images with clinical data greatly improved the performance of classifying malignancies as hepatocellular carcinoma (AUC, 0.985; 95% CI 0.960-1.000), metastatic tumors (0.998; 0.989-1.000), and other primary malignancies (0.963; 0.896-1.000), and the agreement with pathology was 91.9%.These models mined diagnostic information in unenhanced images and clinical data by deep-neural-network, which were different to previous methods that utilized enhanced images. The sensitivity and specificity of almost every category in these models reached the same high level compared to three experienced radiologists. Conclusion: Trained with data in various acquisition conditions, DLS that integrated these models could be used as an accurate and time-saving assisted-diagnostic strategy for liver tumors in clinical settings, even in the absence of contrast agents. DLS therefore has the potential to avoid contrast-related side effects and reduce economic costs associated with current standard MRI inspection practices for liver tumor patients.

14.
Front Pharmacol ; 11: 812, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32595496

RESUMO

In the chronic phase following ischemic stroke, glial scars can prevent axonal regeneration and the intensification of inflammation. The protective effect of inhibition of glycogen synthase kinase-3ß (GSK3ß) or receptor-interacting protein 1 kinase (RIP1K) on ischemic stroke has been previously reported. The current study examined the effects of RIP1K and GSK3ß on ischemic stroke-induced glial scar formation. To investigate this, we used an in vivo model of ischemic stroke based on middle cerebral artery occlusion for 90 min followed by reperfusion for 7 d, and an in vitro model in primary cultured astrocytes involving oxygen and glucose deprivation for 6 h followed by reoxygenation for 24 h. Both in vivo and in vitro, we found that SB216763, a GSK3ß inhibitor, and necrostatin-1 (Nec-1), a RIP1K inhibitor, decreased levels of glial scar markers, including glial fibrillary acidic protein (GFAP), neurocan, and phosphacan. SB216763 and Nec-1 also decreased levels of inflammatory related cytokines, including interleukin-6 (IL-6), interleukin-1 ß (IL-1ß), and tumor necrosis factor-α (TNF-α). However, only Nec-1 increased the level of interleukin-1 receptor antagonist. Concurrent neutralization of TNF-α, IL-1ß, and IL-6 with their antibodies provided better reduction in oxygen and glucose deprivation-induced increases in scar markers than obtained with separate use of each antibody. Further investigations showed that SB216763 reduced the levels of necroptosis-related proteins, including RIP1K, p-RIP1K, RIP3K, p-RIP3K, mixed lineage kinase domain-like protein (MLKL), and p-MLKL, while Nec-1 decreased the expression of p-GSK3ß. Compared with Nec-1 (10 µM) and SB216763 (1 µM) alone, Nec-1 and SB216763 in combination reduced levels of GFAP, neurocan, and inflammatory-related cytokines. In conclusion, inhibition of GSK3ß or RIP1K reduced glial scar formation induced by ischemic stroke. The underlying mechanisms might be at least, partially related to reducing levels of inflammatory-related cytokines and to blocking an interaction between GSK3ß- and RIP1K-mediated pathways.

15.
Hortic Res ; 7: 75, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32377365

RESUMO

The mangrove Kandelia obovata (Rhizophoraceae) is an important coastal shelterbelt and landscape tree distributed in tropical and subtropical areas across East Asia and Southeast Asia. Herein, a chromosome-level reference genome of K. obovata based on PacBio, Illumina, and Hi-C data is reported. The high-quality assembled genome size is 177.99 Mb, with a contig N50 value of 5.74 Mb. A large number of contracted gene families and a small number of expanded gene families, as well as a small number of repeated sequences, may account for the small K. obovata genome. We found that K. obovata experienced two whole-genome polyploidization events: one whole-genome duplication shared with other Rhizophoreae and one shared with most eudicots (γ event). We confidently annotated 19,138 protein-coding genes in K. obovata and identified the MADS-box gene class and the RPW8 gene class, which might be related to flowering and resistance to powdery mildew in K. obovata and Rhizophora apiculata, respectively. The reference K. obovata genome described here will be very useful for further molecular elucidation of various traits, the breeding of this coastal shelterbelt species, and evolutionary studies with related taxa.

16.
Tohoku J Exp Med ; 251(1): 31-37, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32434999

RESUMO

Motor skill practice improves performance not only in the trained - but also in the untrained contralateral limb - a phenomenon called as interlimb transfer. Handedness affects motor skill acquisition and interlimb transfer, but it remains unknown whether handedness affects interlimb transfer when practicing with the dominant or non-dominant limb. We have hypothesized that interlimb transfer of skill acquisition differs between left- and right-handed participants, and that right- as compared with left-hand motor skill practice shows greater interlimb transfer, regardless of handedness. Strongly left-hand (n = 12, aged 27.3 ± 4.4 years; 3 female) and right-hand dominant (n = 12, 20.7 ± 3.8 years; 5 female) subjects with no history of neurological or orthopedic disorders performed the grooved pegboard test before and after 4 blocks of practice on the same apparatus. Subjects were timed on their speed of the task. Right-handed subjects failed to improve manual performance in their right hand after right- or left-hand motor practice. In contrast, they showed improvement on the left hand in each condition. These data suggest greater interlimb transfer after right-hand motor skill practice, but no interlimb transfer after left-hand practice. On the other hand, our results show consistent interlimb transfer effects in left-handed subjects, irrespective of whether the dominant left or the non-dominant right arm has been initially trained. In conclusion, our results add to the body of literature by detecting the differences in the magnitude of motor skill acquisition and interlimb transfer between left- and right-handed subjects after short-term unilateral motor skill practice.

17.
Angew Chem Int Ed Engl ; 59(32): 13232-13237, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32431056

RESUMO

The in situ tracking of the pyrolysis of a binary molecular cluster [Zn7 (µ3 -CH3 O)6 (L)6 ][ZnLCl2 ]2 is presented with one brucite disk and two mononuclear fragments (L=mmimp: 2-methoxy-6-((methylimino)-methyl)phenolate) to porous carbon using TG-MS from 30 to 900 °C. Following up the spilled gas product during the decomposed reaction of zinc cluster along the temperature rising, and in conjunction with XRD, SEM, BET and other materials characterization, where three key steps were observed: 1) cleavage of the bulky external ligand; 2) reduction of ZnO and 3) volatilization of Zn. The real-time-dependent phase-sequential evolution of the remaining products and the processing of pore forming template transformation are proposed simultaneously. The porous carbon structure featuring a uniform nano-sized pore distribution synthesized at 900 °C with the highest surface area of 1644 m2 g-1 and pore volume of 0.926 cm3 g-1 exhibits the best known capacitance of 662 F g-1 at 0.5 A g-1 .

18.
Enzyme Microb Technol ; 136: 109537, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32331719

RESUMO

Given their special action mechanisms and structural simplicity, L-amino acid ligases (Lals) are considered to be desirable tools for the catalytic biosynthesis of dipeptides. Ywf E (BacD) was the first Lal identified and was shown to be involved in the biosynthesis of a potent antibacterial, bacilysin, since then, various novel Lals have been discovered. Each Lal has different substrate spectra and is capable of synthesizing different dipeptides. Owning to their great potentials for producing bioactive dipeptides of industrial importance, in this review, recent developments of Lals are discussed, including their structures, action mechanisms, applications and the advantages and disadvantages of different Lals. In addition, protein engineering of Lals to improve their substrate specificity and catalytic performance is also discussed.


Assuntos
Aminoácidos/metabolismo , Bactérias/enzimologia , Dipeptídeos/biossíntese , Ligases/metabolismo , Biocatálise , Microbiologia Industrial , Engenharia de Proteínas , Especificidade por Substrato
19.
Zhen Ci Yan Jiu ; 45(4): 293-8, 2020 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-32333534

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Hegu"(LI4) and "Zusanli"(ST36)on changes of intestinal sensitivity and colonic motility and expression of colonic 5-hydroxytryptamine 3A receptor (5-HT3AR) in irritable bowel syndrome (IBS) rats, so as to reveal its mechanism underlying improvement of IBS. METHODS: A total of 40 neonatal Wistar rats were randomly and equally divided into normal control, model, LI4 and ST36 groups (n=10). The IBS model was induced by mother-infant separation, acetic acid enema and colorectal distension (CRD). EA (2 Hz/100 Hz, a tolerable strength) was applied to bilateral LI4 and ST36 for 20 min, once every other day for 5 times. The Bristol stool form scale was used to assess the gastrointestinal function, and the latency and number of abdominal muscular contraction waves of abdominal withdrawal reflex (AWR) were used to evaluate the intestinal sensitivity and motility respectively. The immunoactivity of 5-HT3AR of the colon tissue was detected by immunohistochemistry. RESULTS: After modeling, the score of Bristol fecal form scale, number of muscular contraction waves and expression levels of colonic 5-HT3AR in the myometrium and mucosal layers were significantly increased (P<0.01), and the latency of muscular initial contraction wave was obviously shortened in the model group relevant to the normal control group (P<0.01). After the intervention, the increased Bristol fecal form score, number of muscular contraction waves and expression levels of 5-HT3AR in the myometrium and mucosal layers as well as the decreased latency of muscular contraction were reversed in both LI4 and ST36 groups (P<0.01, P<0.05). The effect of EA of ST36 was significantly superior to those of EA-LI4 in lowering Bristol fecal scale score and 5-HT3AR expression in the muscular layer (P<0.01), but obviously inferior to those of EA-LI4 in increasing the latency of of muscular initial contraction wave and down-regulating muscular contraction waves and 5-HT3AR expression in the mucosal layer (P<0.05, P<0.01). CONCLUSION: Both EA-LI4 and EA-ST36 can significantly improve the symptoms of abdominal pain and diarrhea, but EA-LI4 is better in suppressing intestinal high sensitivity, and EA-ST36 is better in promoting intestinal motility, suggesting a specificity of effect of acupoints of different meridians.


Assuntos
Eletroacupuntura , Síndrome do Intestino Irritável , Pontos de Acupuntura , Animais , Feminino , Meridianos , Ratos , Ratos Wistar
20.
Rev Sci Instrum ; 91(3): 033709, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32259980

RESUMO

The traditional algorithm for compressive reconstruction has high computational complexity. In order to reduce the reconstruction time of compressive sensing, deep learning networks have proven to be an effective solution. In this paper, we have developed a single-pixel imaging system based on deep learning and designed the binary sampling Res2Net reconstruction network (Bsr2-Net) model suitable for binary matrix sampling. In the experiments, we compared the structural similarity, peak signal-to-noise ratio, and reconstruction time using different reconstruction methods. Experimental results show that the Bsr2-Net is superior to several deep learning networks recently reported and closes to the most advanced reconstruction algorithms.

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