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1.
Acta Crystallogr C Struct Chem ; 77(Pt 6): 257-261, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34089248

RESUMO

A novel three-dimensional CdII coordination framework, namely, poly[{µ-bis[4-(2-methylimidazol-1-yl)phenyl] ether-κ2N3:N3'}(µ-naphthalene-1,4-dicarboxylato-κ3O1:O4,O4')cadmium(II)], [Cd(C12H6O4)(C20H18N4O)]n or [Cd(1,4-NDC)(BMIOPE)]n, where 1,4-H2NDC is naphthalene-1,4-dicarboxylic acid and BMIOPE is bis[4-(2-methylimidazol-1-yl)phenyl] ether, has been prepared and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. The compound displays a novel fourfold interpenetrating diamond-like network. In addition, it not only shows a strong fluorescence emission in the solid state, but also exhibits excellent photocatalytic activity for the degradation of methylene blue (MB) at room temperature.

2.
Oxid Med Cell Longev ; 2021: 5554932, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995823

RESUMO

TF IIB-related factor 1 (Brf1) is a key transcription factor of RNA polymerase III (Pol III) genes. Our early studies have demonstrated that Brf1 and Pol III genes are epigenetically modulated by histone H3 phosphorylation. Here, we have further investigated the relationship of the abnormal expression of Brf1 with a high level of phosphorylated AMPKα (pAMPKα) and explored the role and molecular mechanism of pAMPKα-mediated dysregulation of Brf1 and Pol III genes in lung cancer. Brf1 is significantly overexpressed in lung cancer cases. The cases with high Brf1 expression display short overall survival times. Elevation of Brf1 expression is accompanied by a high level of pAMPKα. Brf1 and pAMPKα colocalize in nuclei. Further analysis indicates that the carcinogen MNNG induces pAMPKα to upregulate Brf1 expression, resulting in the enhancement of Pol III transcription. In contrast, inhibiting pAMPKα decreases cellular levels of Brf1, resulting in the reduction of Pol III gene transcription to attenuate the rates of cell proliferation and colony formation of lung cancer cells. These outcomes demonstrate that high Brf1 expression reveals a worse prognosis in lung cancer patients. pAMPKα-mediated dysregulation of Brf1 and Pol III genes plays important roles in cell proliferation, colony formation, and tumor development of lung cancer. Brf1 may be a biomarker for establishing the prognosis of lung cancer. It is a new mechanism that pAMPKα mediates dysregulation of Brf1 and Pol III genes to promote lung cancer development.

3.
Chem Asian J ; 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33974731

RESUMO

Two-dimensional (2D) hybrid perovskites are recently emerging as a potential family of semiconductors for versatile optoelectronic applications. Currently, the "perovskitizer" moieties are rigidly limited to small-size cations, while few 2D metal-halides containing guanidinium cations inside perovskite cages have been studied for photodetection. Herein, we present a new 2D hybrid perovskite, (i-BA)2 (G)Pb2 I7 (where G is guanidinium and i-BA is isobutylammonium), which adopts a bilayered framework of {GPb2 I7 }. Single-crystal structure analyses disclose that G cations act as the perovskitizer, confined in the flexible perovskite cages formed by the distorted PbI6 octahedra. Such inorganic sheets are crucial to the superior semiconducting properties and optical bandgap, as verified by the density functional theory calculation. Furthermore, its planar crystal-array photodetector shows fascinating photoelectric performance, including a quite low dark current (∼4.6×10-11  A), a large current switching ratio (∼1.0×103 ), and a notable photo-responsivity of ∼0.72 A W-1 , suggesting great potential of (i-BA)2 (G)Pb2 I7 for photodetection.

4.
Oral Dis ; 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33979023

RESUMO

OBJECTIVE: Incisors tubed prosthesis with bilateral anterior elevation (BAE) relation had been reported to stimulate the proliferative response in the mandibular condylar cartilage of mice, thus the prosthetic occlusion elevation had been proposed to treat cartilage degeneration. Currently, we aimed to detect the long-term effect of BAE on temporomandibular joints (TMJs). MATERIALS AND METHODS: Twelve 6-week-old female mice were assigned to age-matched control and BAE groups (n = 6). Micro-CT images and the macro- and micro-morphology of the mandibular condyles were analyzed at 29 weeks. RESULTS: Compared with the age-matched controls, in BAE group, there were loss of subchondral cortical bone and heavy loss of the subchondral trabecular bone at the superior sites of the TMJ condyles, but hyperostosis at the inferior sites as revealed by micro-CT images and histological slices. In BAE group, cartilage thickness and matrix area were increased with upregulated expression of type II, type X collagen, and Ki67, but the expression of cleaved caspase-3 was downregulated (all, p < 0.05). CONCLUSION: In addition to cartilage thickening, long-term BAE induces loss of the subchondral cortical bone and heavy loss of the underneath subchondral trabecular bone, but hyperostosis further underneath. Using BAE as a treatment remains double-edged.

5.
Environ Pollut ; 281: 116999, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33799206

RESUMO

Understanding how the seedling establishment method affects arsenic (As) accumulation in rice is important for safe agricultural production. In a field experiment with three seedling establishment methods and two rice cultivars, the effects of direct seeding (DS), manual transplanting (MT), and seedling throwing (ST) on root morphological indices and the distribution, translocation, and accumulation of As in rice tissues across growth stages were compared. DS method resulted in the greatest accumulation of As in the two rice cultivars and led to more As distributed in aboveground tissues during the entire growth period. Especially in DS brown rice, the concentration of total As increased by 24.0%-40.8%, and that of inorganic As increased by 24.4%-40.0%, compared with the concentrations in MT and ST rice. A multiple regression model was developed with root morphological indices and the total As concentration in brown rice, and the R2 value of the model was 0.819, which was significant at the 1% level. Compared with the other establishment methods, the thinner diameters, smaller volumes, larger specific surface areas, and greater numbers of root tips in DS rice roots across growth stages promoted As uptake. The concentrations of As in root tips were approximately five times greater than those in the root base, and root tips were the key factor determining the difference in As accumulation in rice roots under the different seedling establishment methods. The results of this study demonstrate that the choice of an appropriate rice seedling establishment method is important to avoid the environmental consequences of As contamination and safely produce rice grain. Therefore, despite the current trend of increased use of DS, transplantation is recommended as a safer pattern of rice seedling establishment in As-contaminated areas.


Assuntos
Arsênico , Oryza , Poluentes do Solo , Arsênico/análise , Raízes de Plantas/química , Plântula/química , Poluentes do Solo/análise
6.
Development ; 148(9)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33914867

RESUMO

A key step in the activation of canonical Wnt signaling is the interaction between ß-catenin and Tcf/Lefs that forms the transcription activation complex and facilitates the expression of target genes. Eukaryotic initiation factor 4A3 (EIF4A3) is an ATP-dependent DEAD box-family RNA helicase and acts as a core subunit of the exon junction complex (EJC) to control a series of RNA post-transcriptional processes. In this study, we uncover that EIF4A3 functions as a Wnt inhibitor by interfering with the formation of ß-catenin/Tcf transcription activation complex. As Wnt stimulation increases, accumulated ß-catenin displaces EIF4A3 from a transcriptional complex with Tcf/Lef, allowing the active complex to facilitate the expression of target genes. In zebrafish embryos, eif4a3 depletion inhibited the development of the dorsal organizer and pattern formation of the anterior neuroectoderm by increasing Wnt/ß-catenin signaling. Conversely, overexpression of eif4a3 decreased Wnt/ß-catenin signaling and inhibited the formation of the dorsal organizer before gastrulation. Our results reveal previously unreported roles of EIF4A3 in the inhibition of Wnt signaling and the regulation of embryonic development in zebrafish.

7.
Anim Biosci ; 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33902177

RESUMO

Objective: The effects of maternal dietary energy levels on breast muscle fibre development in offspring of broiler breeders were investigated. Methods: A total of 480 20-week-old Arbor Acres (AA) healthy female broiler breeders, with an average body weight of 2.33±0.01 kg, were randomly divided into 4 treatment groups with 6 replicates and 20 broiler breeders for each replicate and fed a corn and soybean meal diet with 100%, 80%, 70%, and 50% energy levels, respectively. Approximately 300 eggs per treatment were collected for incubation for 6 days. Then, 120 0-day-old female broilers at each energy level were randomly selected and divided into 6 replicates with 20 broilers for each replicate, with this experimental phase with the offspring lasting for 49 days. Results: Compared with the 100% energy group, the breast muscle fibre diameter at embryonic day 21 in the 80% energy group was significantly reduced (P < 0.05). In the 80% energy group, the muscle fibre density of the breast increased significantly (P < 0.05) at embryonic days 15 and 21. The breast muscle fibre diameter of the offspring in each group was significantly decreased (P < 0.05) on the 1st day. The breast muscle sarcomere length of the embryos in the 80% energy group was significantly higher (P < 0.05) than those in the 70% and 50% energy groups. Compared with the 100% energy group, the expression of the myostatin gene in the offspring was significantly decreased (P < 0.05). Conclusion: In conclusion, the effects of a maternal dietary energy level of 80% in this study were found to be optimal for breast muscle fibre development in offspring, which indicated that the metabolic energy level of AA broilers of 9.36 MJ/kg for the mid-term diet for laying eggs has a more practical significance.

8.
Mol Cell Biochem ; 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33830396

RESUMO

The hydrogen-rich water (HW) has been reported to possess a beneficial role in patients with diabetes. However, a systemic evaluation with an appropriate animal model is necessary to reveal its mechanisms and efficacy. Herein, the protective effects of drinking HW on lipid and glucose metabolism, oxidative stress, and inflammation in type 2 diabetes mellitus (T2DM) rats were investigated. The well-modeled T2DM rats (induced by high-fat diet combined with low-dose streptozotocin (STZ) injection) were divided into two groups (n ≥ 15 of each): fed a high-fat diet and drinking distilled water or HW at a constant concentration above 1.0 ppm; normal rats were used as control group (n ≥ 10): fed a regular diet and drinking distilled water. Several biomarkers of lipid and glucose metabolism, oxidative stress ,and inflammation were evaluated after drinking distilled water or HW for 3 weeks. The effect of HW on liver, kidney, and spleen of T2DM rats was also analyzed by HE and Oil Red O staining. The results showed that drinking HW suppressed the increase in glucose, total cholesterol, oxidative stress, and inflammation. Moreover, HW also ameliorates hyperglycemia-induced liver, kidney, and spleen dysfunction. Overall, this study indicates that patients with T2DM may be able to improve their condition by supplementing HW as daily drinking water.

9.
Chemistry ; 2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33928680

RESUMO

Two-dimensional (2D) organic-inorganic hybrid perovskites, benefiting from their natural anisotropy of quantum-well motifs and optical properties, have shown remarkable polarization-dependent responses superior to the 3D counterparts. Here, for the first time, multiwavelength polarization-sensitive detectors were fabricated by using single crystals of a guanidine-based 2D hybrid perovskite, (BA)2 (GA)Pb2 I7 (where BA+ is n-butylammonium and GA+ is guanidium). Its unique 2D quantum-well structure results in strong crystallographic-dependence of optical absorption. Strikingly, our crystal-based photodetector exhibits a prominent photocurrent dichroic ratio (Imax /Imin ) of ∼2.2 at 520 nm, higher than the typical 2D inorganic materials (GeSe, ∼1.09, PdSe2 , ∼1.8). In addition, notable dichroic ratios of 1.29 and 1.23 at 405 nm and 637 nm are also created for the multiwavelength polarized-light detection. The prominent detecting performances, including low dark current (1.6×10-11  A), considerable on/off ratio (∼2×103 ), high photodetectivity (∼3.3×1011 Jones) and responsivity (∼12.01 mA W-1 ), make (BA)2 (GA)Pb2 I7 a promising candidate for polarized-light detection. This work sheds light on the rational engineering of new 2D hybrid perovskites for the high-performance optoelectronic device applications.

10.
J Sep Sci ; 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33856741

RESUMO

Highly hydrophilic magnetic molecularly imprinted polymers were prepared through a surface imprinting technique for dispersive solid-phase extraction coupled with high-performance liquid chromatography to detect trace levels of ten sulfonamides in animal-derived samples. The obtained imprinted polymers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and adsorption experiments, which exhibited excellent specific adsorption for template sulfamethazine in aqueous solution. Moreover, the adsorption process could be completed within 25 min. Under the optimum conditions, the method exhibits good linear performance in the range of 5-to 10 mg/L, limits of detection ranging from 0.57 to 1.50 µg/L, and good recoveries of 85.09-110.93% in the spiked samples (chicken, cow milk, and goat milk). The proposed detection method not only avoids the use of organic solvents but also simplifies the pretreatment procedure via excellent magnetic properties. Furthermore, the method shows great potential for the rapid detection of drug residues.

11.
Mater Sci Eng C Mater Biol Appl ; 123: 111996, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812616

RESUMO

Titanium dioxide (TiO2) is a widely used biomaterial. It is a great challenge to confer antibacterial and antithrombotic properties to TiO2 while maintaining its cell affinity. Here, we developed a new strategy to achieve the above goal by comprehensively controlling the chemical cues and geometrical cues of the surface of TiO2. Using colloidal etching technology and UV irradiation treatment, we obtained the photofunctionalized nano-micro-honeycomb structured TiO2. The honeycomb structured increased the photocatalytic activity of TiO2, which endowed TiO2 with photo-induced superhydrophilicity to inhibit bacterial adhesion. The high photocatalytic activity also induced the strong photocatalytic oxidation of TiO2 surface organic adsorbates to suppress fibrinogen and platelet attachment. In addition, owing to the micropore trapping-isolation effect on the bacteria and the nano-frames' contact guidance effect on the growth and spreading of platelet pseudopods, the honeycomb structure also shows a considerable inhibiting effect on bacterial and platelet adhesion. Therefore, due to the controlled chemical and geometrical cues' synergistic effect, the photo-functionalized TiO2 honeycomb structure shows excellent bacterial-adhesion resistance and antithrombotic properties. More importantly, the photo-functionalized TiO2 honeycomb did not inhibit the adhesion and growth of endothelial cells (ECs) after culturing for 3 d, indicating a good cell affinity that the traditional antifouling surfaces do not possess.


Assuntos
Células Endoteliais , Titânio , Bactérias , Materiais Biocompatíveis , Titânio/farmacologia
12.
J Am Soc Mass Spectrom ; 32(6): 1319-1325, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-33754701

RESUMO

Top-down proteomics is a key mass spectrometry-based technology for comprehensive analysis of proteoforms. Proteoforms exhibit multiple high charge states and isotopic forms in full MS scans. The dissociation behavior of proteoforms in different charge states and subjected to different collision energies is highly variable. The current widely employed data-dependent acquisition (DDA) method selects a narrow m/z range (corresponding to a single proteoform charge state) for dissociation from the most abundant precursors. We describe here Mesh, a novel dissociation strategy, to dissociate multiple charge states of one proteoform with multiple collision energies. We show that the Mesh strategy has the potential to generate fragment ions with improved sequence coverage and improve identification ratios in top-down proteomic analyses of complex samples. The strategy is implemented within an open-source instrument control software program named MetaDrive to perform real time deconvolution and precursor selection.

13.
Nano Lett ; 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33705149

RESUMO

Graphene-based one-dimensional macroscopic assemblies (GBOMAs) have attracted great attention and extensive efforts have been devoted to enabling great progress. However, their applications are still restricted to less functionalized electronics, and the superior potentials remain scarce. Herein, inspired by natural scallion structure, a novel strategy was introduced to effectively improve battery performances through the mesoscale scallion-like wrapping of graphene. The obtained RGO/Ag-Li anodes demonstrated an ultralow overpotential of ∼11.3 mV for 1800 h at 1 mA cm-2 in carbonate electrolytes, which is superior to those of the most previous reports. Besides, this strategy can also be further expanded to the high mass loading of various cathode nanomaterials, and the resulting RGO/LiFePO4 cathodes exhibited remarkable rate performance and cycle stability. This work opens a new avenue to explore and broaden the applications of GBOMAs as scaffolds in fabricating full lithium batteries via maximizing their advantages derived from the unique structure and properties.

14.
Artigo em Inglês | MEDLINE | ID: mdl-33591715

RESUMO

In this paper, the aluminum (Al) treatment-induced doping effect on the formation of conductive source-drain (SD) regions of self-aligned top-gate (SATG) amorphous indium gallium zinc oxide (a-InGaZnO or a-IGZO) thin-film transistors (TFTs) is systematically investigated. Average carrier concentration over 1 × 1020 cm-3 and sheet resistance of around 500 Ω/sq result from the Al reaction doping. It is shown that the doping effect is of bulk despite the treatment at the surface. The doping process is disclosed to be a chemical oxidation-reduction reaction, that generates defects of oxygen vacancies and metal interstitials at the metal/a-IGZO interface. Both the generated oxygen vacancies and metal interstitials act as shallow donors, and the oxygen vacancies diffuse rapidly, leading to the bulk-doping effect. The fabricated SATG a-IGZO TFTs with the Al reaction-doped SD regions exhibit both high performance and excellent stability, featuring a low width-normalized SD resistance of about 10 Ω cm, a decent saturation mobility of 13 cm2/(V s), an off current below 1 × 10-13 A, a threshold voltage of 0.5 V, a slight hysteresis of -0.02 V, and a less than 0.1 V threshold voltage shift under 30 V gate bias stresses for 2000 s.

15.
Turk Neurosurg ; 31(1): 76-82, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33491170

RESUMO

AIM: To investigate the expression patterns of D-serine and N-methyl-D-aspartate (NMDA) receptor 1 in the temporal lobes of patients with intractable epilepsy. MATERIAL AND METHODS: Cortical temporal lobe brain tissue samples were collected from 20 patients with intractable epilepsy and 6 patients with brain trauma. The expression patterns of D-serine and NMDA receptor 1 were detected by immunofluorescence staining and western blot analysis. RESULTS: A total of 20 patients (11 males, 9 females) were included in the present study. D-serine expression was significantly higher in the neurons and glial cells of patients with intractable epilepsy than in control individuals. The mean integrated optical density (IOD) value for the intractable epilepsy group (13.37 ± 1.88) was significantly higher than that for the control group (9.27 ± 0.62, p < 0.05). The mean absorbance value of the NMDA receptor 1 protein strip obtained from intractable epileptic patients was 0.4175 ± 0.2321, which was significantly higher than the value of 0.2402 ± 0.1458 for the control group (p < 0.05). CONCLUSION: D-serine and NMDA receptor 1 expressions increased significantly in patients with intractable epilepsy compared with control patients. Therefore, the D-serine signaling pathway may represent a potential neurochemical target for epilepsy treatment.


Assuntos
Epilepsia Resistente a Medicamentos/genética , Epilepsia Resistente a Medicamentos/metabolismo , Receptores de N-Metil-D-Aspartato/biossíntese , Receptores de N-Metil-D-Aspartato/genética , Serina/biossíntese , Serina/genética , Adulto , Epilepsia Resistente a Medicamentos/cirurgia , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Lobo Temporal/metabolismo , Lobo Temporal/cirurgia
16.
Pediatr Res ; 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33469185

RESUMO

BACKGROUND: Necrotizing enterocolitis (NEC) is the most common gastrointestinal disorder in premature neonates. Possible therapeutic approaches are centered on promoting maturation of the gastrointestinal mucosal barrier. Studies have demonstrated that antenatal administration of corticosteroids can decrease NEC incidence and mortality. METHODS: Pregnant rat dams were administered dexamethasone 48 h prior to delivery. The pups were subjected to an experimental NEC-like injury protocol. Ileal tissues and sera were collected and evaluated for inflammatory cytokines, gut permeability and expressions and localizations of tight junction proteins, and surfactant protein-D by immunohistochemistry/immunofluorescent staining. Intestinal epithelial cells (IEC-6) were pretreated with SP-D to examine the effect of SP-D on tight junction protein expressions when challenged with platelet-activating factor and lipopolysaccharide to model proinflammatory insults. RESULTS: Antenatal dexamethasone reduced systemic inflammation, preserved intestinal barrier integrity, and stimulated SP-D expression on the intestinal mucosal surface in pups exposed to NEC-like injury. Pretreatment of SP-D blocked platelet-activating factor/lipopolysaccharide-induced tight junction disruption in IEC-6 cells in vitro. CONCLUSIONS: Antenatal dexamethasone preserves the development of intestinal mucosal barrier integrity and reduces incidence and morbidity from an experimental NEC-like injury model. Dexamethasone upregulation of intestinal SP-D-protective effects on tight junction proteins. IMPACT: Antenatal administration of dexamethasone can function in concert with intestinal surfactant protein-D to decrease systemic inflammatory responses, and protect intestinal barrier integrity in a neonatal rat model of NEC. A novel role of intestinal SP-D in preserving tight junction protein structures under inflammatory conditions. We describe the intestinal SP-D-an overlooked role of antenatal dexamethasone in neonatal NEC?

17.
IEEE Trans Biomed Eng ; PP2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33156776

RESUMO

Evaluating progress throughout a patient's rehabilitation episode is critical for determining the effectiveness of the selected treatments and is an essential ingredient in personalised and evidence-based rehabilitation practice. The evaluation process is complex due to the inherently large human variations in motor recovery and the limitations of commonly used clinical measurement tools. Information recorded during a robot-assisted rehabilitation process can provide an effective means to continuously quantitatively assess movement performance and rehabilitation progress. However, selecting appropriate motion features for rehabilitation evaluation has always been challenging. This paper exploits unsupervised feature learning techniques to reduce the complexity of building the evaluation model of patients' progress. A new feature learning technique is developed to select the most significant features from a large amount of kinematic features measured from robotics, providing clinically useful information to health practitioners with reduction of modeling complexity. A novel indicator that uses monotonicity and trendability is proposed to evaluate kinematic features. The data used to develop the feature selection technique consist of kinematic data from robot-aided rehabilitation for a population of stroke patients. The selected kinematic features allow for human variations across a population of patients as well as over the sequence of rehabilitation sessions. The study is based on data records pertaining to 41 stroke patients using three different robot assisted exercises for upper limb rehabilitation. Consistent with the literature, the results indicate that features based on movement smoothness are the best measures among 17 kinematic features suitable to evaluate rehabilitation progress.

18.
ACS Appl Mater Interfaces ; 12(45): 50527-50533, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33140637

RESUMO

The development of photovoltaic devices with a high output voltage offers great opportunities for emerging internet of things (IoT) sensors and low-power-consumption electronics. However, the photovoltage of solar cells is yet to satisfy the requirement of driving voltage for most applications. Here, we demonstrate a wide-band gap CsPbBr3-based solar cell with a heterostructured light absorber based on amino acid-modulated CsPbBr3 and CdSe quantum dots (QDs). Compared with the single absorbing layer device, the heterostructured device exhibits a low nonradiative recombination loss, which is strongly correlated to the high external electroluminescence of the device. In addition, in the heterostructured solar cells, carrier transfer from the perovskite to CdSe QDs induces the conduction band bending of CdSe QDs, leading to a large splitting of the quasi-Fermi levels. As a result, a remarkable photovoltage up to 1.75 V is achieved for the wide-band gap solar cells, representing an extremely low voltage deficit of 250 mV. Furthermore, the CsPbBr3-based solar cells exhibit a weak light intensity dependence, showing a photovoltage of 1.59 V under room light conditions. Our work not only provides an effective approach for the design of high-photovoltage solar cells but also paves the ways of using photovoltaic devices for various applications with low driving voltage schemes.

19.
Front Physiol ; 11: 541974, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33132916

RESUMO

A forward head and rounded shoulder posture is a poor posture that is widely seen in everyday life. It is known that sitting in such a poor posture with long hours will bring health issues such as muscle pain. However, it is not known whether sitting in this poor posture for a short period of time will affect human activities. This paper investigates the effects of a short-duration poor posture before some typical physical activities such as push-ups. The experiments are set up as follows. Fourteen male subjects are asked to do push-ups until fatigue with two surface electromyography (sEMG) at the upper limb. Two days later, they are asked to sit in this poor posture for 15 min with eight sEMG sensors located at given back muscles. Then they do the push-ups after the short-duration poor posture. The observations from the median frequency of sEMG signals at the upper limb indicate that the short-duration poor posture does affect the fatigue procedure of push-ups. A significant decreasing trend of the performance of push-ups is obtained after sitting in this poor posture. Such effects indicate that some parts of the back muscles indeed get fatigued with only 15 min sitting in this poor posture. By further investigating the time-frequency components of sEMG of back muscles, it is observed that the low and middle frequencies of sEMG signals from the infraspinatus muscle of the dominant side are demonstrated to be more prone to fatigue with the poor posture. Although this study focuses only on push-ups, similar experiments can be arranged for other physical exercises as well. This study provides new insights into the effect of a short-duration poor posture before physical activities. These insights can be used to guide athletes to pay attention to postures before physical activities to improve performance and reduce the risk of injury.

20.
Artigo em Inglês | MEDLINE | ID: mdl-33245440

RESUMO

Laccases are versatile oxidases that are capable of decolorizing various synthetic dyes. Recombinant Bacillus amyloliquefaciens laccase was immobilized as magnetic cross-linked enzyme aggregates (M-CLEAs) for application in dye decolorization. Several parameters influencing the activity recovery were evaluated during the synthesis of M-CLEAs. With ammonium sulfate as precipitant, maximum activity was recovered by cross-linking with 0.16% glutaraldehyde for 1 h. The prepared M-CLEAs exhibited improved activity under alkaline conditions. It remained 74% activity after incubation at 60 °C for 5 h. Enhanced tolerance towards NaCl was also observed for the M-CLEAs, with 68% activity remaining in the presence of 1 M NaCl. The immobilized laccase could rapidly decolorize more than 93% of reactive black 5 and indigo carmine in 1 h, while its catalytic efficiency towards reactive blue 19 was relatively low. After four cycles of consecutive reuse, the M-CLEAs could decolorize 92% of indigo carmine. The easy recovery and reusability of M-CLEAs facilitate the potential application of bacterial laccase in dye decolorization.

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