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1.
J Phys Chem A ; 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32187492

RESUMO

Photoinduced ring-opening, decay, and isomerization of spirobenzopyran have been explored by the OM2/MRCI nonadiabatic dynamics simulations based on Tully's fewest-switches surface hopping scheme. The efficient S1 to S0 internal conversion as observed in experiments is attributed to the existence of two efficient excited-state decay pathways. The first one is related to the C-N dissociation, and the second one is done to the C-O dissociation. The C-O dissociation pathway is dominant, and more than 90% trajectories decay to the S0 state via the C-O bond-fission related S1/S0 conical intersections. Near these regions in the S0 state, trajectories can either return to spirobenzopyran or proceed to various intermediates including merocyanine via a series of bond rotations. Our nonadiabatic dynamics simulations also demonstrate that the hydrogen-out-of-plane (HOOP) motion is important for efficient and ultrafast excited-state deactivation. On the other hand, we have also found that the replacement of methyl groups by hydrogen atoms in spirobenzopyran can artificially introduce different intramolecular hydrogen transfers leading to hydrogen-transferred intermediates. This finding is important for the community and demonstrates that such a kind of structural truncation, sometimes, could be problematic, leading to incorrect photodynamics. Our present work provides valuable insights into the photodynamics of spirobenzopyran, which could be helpful for the design of spiropyran-based photochromic materials.

2.
Bioresour Technol ; 305: 123078, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32135351

RESUMO

This research proposed an innovative approach to synchronously enhance the recovery of phosphorus (P) as vivianite and volatile fatty acids (VFAs) during waste activated sludge (WAS) and food waste (FW) co-fermentation. A high performance was achieved under 30% FW addition and pH uncontrolled, which gained 83.09% of TP recovery as high-purity vivianite (93.90%), together with efficient VFAs production (7671 mg COD/L). The FW supplement could enhance VFAs production and subsequently lower pH to contribute to the release of Fe2+ and PO43-. Also, it could dampen disrupting effects of strong acidic pH on microbial cells (lowering LDH release). Moreover, the flexible pH variation caused by biological acidification could maintain relatively higher microbial activities (increasing enzymes' activities), which was advantageous to the biological effects involved in Fe2+ and PO43 release and VFAs generation. Therefore, this research provide a promising and economic alternative to dispose of WAS and FW simultaneously for valuable resource recovery.

3.
Biomed Pharmacother ; 126: 110050, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32135462

RESUMO

Photoreceptor cells are first-order retinal neurons that directly contribute to the formation of vision. Photoreceptor degeneration is the primary cause of vision impairment during the course of retinopathies such as retinitis pigmentosa and age-related macular degeneration, for which photoreceptor-targeted therapies are currently unavailable. Shihu Yeguang Pill (SYP), a classic formula in traditional Chinese medicine, has a long histology of clinical application for the treatment of a wide range of retinopathies in China. However, whether SYP is pharmacological effective at protecting photoreceptor cells is unclear. The current study thus directly addressed the pharmacological implications of SYP in photoreceptor degeneration in a mouse model characterized by bright light-induced retinal degeneration. Non-invasive full-retinal assessment was carried out to evaluate the effect of SYP on the retinal structure and function through optical coherence tomography and electroretinography, respectively. In addition, photoreceptor apoptosis, second-order neuron impairment and reactive changes in retinal microglial and müller cells, hallmark pathologies associated with photoreceptor degeneration, were assessed using immunohistochemistry and real-time PCR analyses. The results showed that SYP treatment attenuated bright light-induced impairment of the retinal structure and function. Moreover, SYP treatment suppressed photoreceptor apoptosis, alleviated the impairment of bipolar and horizontal cells and mitigated the reactive changes of müller and microglial cells in the bright light-exposed retinas. Real-time PCR analyses showed that dysregulated expression of pro-apoptotic c-fos and c-jun and anti-apoptotic bcl-2 as well as proinflammatory TNF-α in the bright light-exposed retinas was partially normalized as a result of SYP treatment. In summary, the work here demonstrates for the first time that SYP treatment protects the retinas from developing bright light-induced photoreceptor degeneration and associated alterations in second-order neurons and glial cells. The findings here thus provide experimental evidence to better support the mechanism-guided clinical application of SYP in the treatment of related retinal degenerative diseases.

4.
J Phys Chem Lett ; : 2470-2476, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32150415

RESUMO

We have employed the QM(CASPT2//CASSCF)/MM method to explore the excited-state isomerization and decay mechanism of a single-bond-rotation locked photoactive yellow protein (PYP) chromophore in wild-type and mutant proteins. The S1 state is a spectroscopically bright state in the Franck-Condon region. In this state, there exist two excited-state isomerization pathways separately related to the clockwise and anticlockwise rotations of the C=C bond. The clockwise path is favorable because of a small barrier of 2 kcal/mol and uses a novel bicycle-pedal unidirectional photoisomerization mechanism in which the involved two dihedral angles rotate asynchronously because of the reinforced hydrogen-bonding interaction between the chromophore and Cys69. Near the twisted S1 minimum, the chromophore hops to the S0 state via the S1/S0 conical intersection. Finally, the R52A mutation has small effects on the excited-state properties and photoisomerization of the locked PYP chromophore. The present work provides new insights for understanding the photochemistry of PYP chromophores in protein surroundings.

5.
Mikrochim Acta ; 187(4): 218, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32166530

RESUMO

A nonenzymatic voltammetric assay for dopamine (DA) was developed based on the combination of three-dimensional graphene (3D Gr) and indium oxide nanosheet arrays (In2O3 NSAs). 3D Gr was prepared by chemical vapor deposition (CVD), and In2O3 NSAs were grown on its surface by hydrothermal synthesis. The results show that 3D Gr maintains a good porous structure (200 µm), and the pore size of In2O3 NSAs is 0.50 µm. Differential pulse voltammetry (DPV) is mainly used to determine the electrochemical properties of In2O3 NSAs/3D Gr. It possesses a sensitivity of 2.69 µA·µM-1·cm-2 towards DA (5-60 µM) at 0.14 V, and the detection limit (LOD) is 0.10 µM (S/N = 3). The recoveries obtained for spiked samples in the real sample detection is 105 (± 8)%. Graphical abstractSchematic representation of DA sensitive detection by growing In2O3 nanosheets arrays on three-dimentional graphene modified ITO.

6.
J Mech Behav Biomed Mater ; 104: 103646, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32174404

RESUMO

STUDY DESIGN: Cadaveric biomechanical with imaging analysis. OBJECTIVE: This study aims to compare the fixation failure between pedicel screws (PS) and cortical screws (CS), thus to investigate their failure mechanisms under vertical migration. SUMMARY OF BACKGROUND DATA: Due to their minimal invasive nature, CS are gaining popularity. However, contradictions exist in the literature regarding whether CS may have superior fixation failure resistance compared to PS under vertical migration. METHODS: Human vertebral specimens were examined under Dual-energy X-ray. For each specimen, PS were inserted on the left and CS on the right with rods secured. Vertical force-displacement tests were applied to rods. MicroCT images were taken pre and post-MTS® for microstructural analysis. RESULTS: The average T-scores of the specimens were -4±0.25. Three phases of force-displacement behaviour featuring different PS and CS failure-resistance were discovered. For phase I, the force required to migrate PS tended to be slightly higher than CS. However, during phase II, a fixation instability occurred for PS and the CS fixation strength was superior. For phase III under large displacement, CS did not require increased force to displace, whereas PS re-stabilised and revealed improved displacement resistance. Both force analysis and microstructural analysis indicated that PS migrated along the direction of the vertical loading, whereas CS had a force component in the longitudinal axis of the screw. CONCLUSIONS: Different failure mechanisms underlay PS and CS under large vertical displacement. PS fail with trabecular bone compaction possibly altering the initial material property surround the screw. CS fail with screw cut-out due to the force component along the screw axis.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32128729

RESUMO

Chlorophyll-a (Chl-a) is the main component of phytoplankton and an important index of water quality. Pearson correlation analysis is conducted on measured Chl-a concentration and band reflectance to determine the sensitive bands or multiband combinations of the Chl-a to input to a support vector machine (SVM) model. An indicator ß is defined to evaluate the model performance of fitting and prediction. The model performs well with the lowest ß (decision coefficient, (R2) = 0.774; root mean square error (RMSE) = 22.636 µg/L) of the validation set. The model test results prove that the model performs well. We analyze the impact factors of the model. The seasonal factor affects the model performance significantly; thus, samples from different seasons should be combined to train the model and inverse the water quality. Noise points reduce the model accuracy significantly; therefore, obvious outliers must be excluded at first. Additionally, the sampling method affects model accuracy, and systematic sampling in the descending order of Chl-a concentration is recommended. The combination of SVM algorithm and remote sensing technology provides a convenient, scientific, and real-time method to monitor and control water quality.

8.
J Ethnopharmacol ; 254: 112733, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32145333

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Zi-shen pill (ZSP), a traditional Chinese medicine, is widely used for the treatment of benign prostatic hyperplasia (BPH) and has remarkable curative effect. AIM OF THE STUDY: To screen the potential 5-Lipoxygenase(5-LOX) inhibitors from ZSP extract. MATERIALS AND METHODS: A new approach based on affinity ultrafiltration-ultra performance liquid chromatography-mass spectrometry(UPLC-MS) was established and validated. Zileuton and glipizide were chosen as positive and negative control drug, respectively. For better screening result, the concentration of 5-LOX enzyme, incubation temperature and time, pH and ion strength were optimized. In addition, 5-LOX inhibitory assay in vitro and molecular docking technique were used for further verification. RESULTS: 20 compounds were characterized in the ultrafiltrate by high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and 16 ligands showed binding ability to 5-LOX. Among them, six ligands were deduced as high-potential 5-LOX inhibitors with their high specific binding values (>2.0). The inhibitory activities of anemarrhenasaponin I, timosaponin AI, nyasol and demethyleneberberine were confirmed by the 5-LOX inhibitory assay for validating the reliability of affinity ultrafiltration approach and the computer-simulated molecular docking technique further clarified the possible mechanism of action between the active compounds and the 5-LOX active sites.

9.
Bone ; 135: 115314, 2020 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-32156663

RESUMO

BACKGROUND: One of the characteristics of osteoporotic bone is the deterioration of trabecular microarchitecture. Previous studies have shown microarchitecture alone can vary the apparent modulus of trabecular bone significantly independent of bone volume fraction (BV/TV) from morphological and topological perspectives. However, modulus is a mechanical quantity and there is a lack of mechanical explanatory parameters. This study aims to propose a novel mechanical parameter to quantify the microarchitecture effect on the apparent modulus of trabecular bone. MATERIALS AND METHODS: Fourteen human female cadaveric vertebrae were scanned with a dual-energy X-ray (DXA) equipment followed by a micro-CT (µCT) system at 18 µm isotropic resolution. Four trabecular bone specimens (3.46 × 3.46 × 3.46 mm) were obtained from each vertebral body and converted to voxel-based micro finite element (µFE) models. The apparent modulus (E) of the µFE model was computed using a linear micro finite element analysis (µFEA). The normalized apparent modulus (E*) was computed as E divided by BV/TV. The relationship between E and BV/TV was analyzed by linear, power-law and exponential regressions. Linear regression was performed between E* and BV/TV. Ineffective bone mass (InBM) was defined as the bone mass with a negligible contribution to the load-resistance and represented by elements with von Mises stress less than a certain stress threshold. InBM was quantified as the low von Mises stress ratio (LSVMR), which is the ratio of the number of InBM elements to the total number of elements in the µFE model. An incremental search technique with coarse and fine search intervals of 10 and 1 MPa, respectively, was adopted to determine the stress threshold for calculating LSVMR of the µFE model. Correlation between E* and LSVMR was analyzed using linear and power-law models for each stress threshold. The threshold producing the highest coefficient of determination (R2) in the correlation between E* and LSVMR was taken as the optimal stress threshold for calculating LSVMR. Linear regression was performed between E and LSVMR. Multiple linear regression of E against both BV/TV and LSVMR was further analyzed. RESULTS: E significantly (p < .001) correlates to BV/TV whereas E* has no significant (p = .75) correlation with BV/TV. Incremental search suggests 59 MPa to be the optimal stress threshold for calculating LSVMR. BV/TV alone can explain 59% of the variation in E using power-law regression model (E = 2254.64BV/TV1.04, R2 = 0.59, p < .001). LSVMR alone can explain 48% of the variation in E using linear regression model (E = 1696.4-1647.1LSVMR, R2 = 0.48, p < .001). With these two predictors taken into consideration, 95% of the variation in E can be explained in a multiple linear regression model (E = 1364.89 + 2184.37BV/TV - 1605.38LSVMR, adjusted R2 = 0.95, p < .001). CONCLUSION: LSVMR can be adopted as the mechanical parameter to quantify the microarchitecture effect on the apparent modulus of trabecular bone.

10.
Medicine (Baltimore) ; 99(8): e19317, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32080149

RESUMO

Endovenous laser ablation (EVLA) and ultrasound-guided foam sclerotherapy (UGFS) have largely replaced traditional surgery for treatment of varicose veins (VVs) with active venous leg ulcers (VLUs), and multiple combined modes have emerged. A retrospective cohort study was performed to compare the effect of traditional surgery (high ligation and stripping followed with compression [compression plus HL-S]) to high ligation-endovenous laser ablation-foam sclerotherapy followed with compression (compression plus HL-EVLA-FS) on the treatment of active VLUs.Data of active VLUs treated in our center from 2008 to 2017 and followed up for 1 year were analyzed. The intervention measures in the first 5 years were compression plus HL-S, and in the following 5 years were compression plus HL-EVLA-FS. The primary outcome was ulcer healing time. The secondary outcomes were the VVs occlusion and clinical success as assessed by a change in venous clinical severity score (VCSS) and complications.The study included 120 patients and 200 patients treated with HL-S and HL-EVLA-FS, respectively, during 2008 to 2017. The average ulcer healing time were 2.3 ±â€Š2.4 and 1.7 ±â€Š1.7 months, respectively. Significant difference was found in the cumulative ulcers healing rate between the two groups (Hazard ratio [HR] and 95% confidence interval [CI] was respectively 1.458 and 1.140-1.865, P = .0002), but no difference was found in the VVs occlusion (HR and 95% CI was respectively 1.005 and 0.774-1.3071, P = .967). Significant difference occurred in 6 months and 12 months post-operatively in the VCSS change and in the procedure data and some complications between the 2 groups.In conclusion, the treatment of HL-EVLA-FS can accelerate the healing of VLUs, improve the VCSS and present superior procedure data. However, no advantage could be found in the VVs occlusion compared with control group.


Assuntos
Terapia a Laser , Ligadura , Escleroterapia , Úlcera Varicosa/terapia , Procedimentos Cirúrgicos Vasculares , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Veia Safena/cirurgia , Índice de Gravidade de Doença , Meias de Compressão , Cicatrização
11.
Proc Natl Acad Sci U S A ; 117(8): 3938-3943, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32047032

RESUMO

Thin solids often develop elastic instabilities and subsequently complex, multiscale deformation patterns. Revealing the organizing principles of this spatial complexity has ramifications for our understanding of morphogenetic processes in plant leaves and animal epithelia and perhaps even the formation of human fingerprints. We elucidate a primary source of this morphological complexity-an incompatibility between an elastically favored "microstructure" of uniformly spaced wrinkles and a "macrostructure" imparted through the wrinkle director and dictated by confinement forces. Our theory is borne out of experiments and simulations of floating sheets subjected to radial stretching. By analyzing patterns of grossly radial wrinkles we find two sharply distinct morphologies: defect-free patterns with a fixed number of wrinkles and nonuniform spacing and patterns of uniformly spaced wrinkles separated by defect-rich buffer zones. We show how these morphological types reflect distinct minima of a Ginzburg-Landau functional-a coarse-grained version of the elastic energy, which penalizes nonuniform wrinkle spacing and amplitude, as well as deviations of the actual director from the axis imposed by confinement. Our results extend the effective description of wrinkle patterns as liquid crystals [H. Aharoni et al, Nat. Commun. 8, 15809 (2017)], and we highlight a fascinating analogy between the geometry-energy interplay that underlies the proliferation of defects in the mechanical equilibrium of confined sheets and in thermodynamic phases of superconductors and chiral liquid crystals.

12.
Dalton Trans ; 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32101240

RESUMO

Three-dimensional graphene (3D GR)-based hybrids have received significant attention due to their unique structures and promising applications in supercapacitors. In this paper, 3D GR with small pore sizes has been prepared by chemical vapor deposition using commercial nickel nanowires as the template. After nitric acid treatment, the hydrophilicity of 3D GR improved. Polyaniline nanowire arrays (PANI NWAs) have been successfully grown on its surface by in situ polymerization to obtain hybrid PANI NWA/3D GR. The results show that PANI NWAs with a length of ∼300 nm vertically grow on 3D GR with a pore diameter of ∼2 µm. The small pore size of 3D GR not only improves the mechanical properties of 3D GR, but also provides numerous sites for the growth of PANI NWAs. Meanwhile, PANI NWAs provide a shorter ion diffusion path and larger contact area with the electrolyte. Due to the unique structure, the hybrid exhibits a high specific capacitance of 789.9 F g-1 at 10 mV s-1. When it is assembled into a symmetric supercapacitor, it exhibits an energy density of 32.2 W h kg-1 at a power density of 793.3 W kg-1 and maintains a good cycle stability of 90% after 5000 cycles at 1.0 A g-1.

13.
Clin Exp Rheumatol ; 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32083545

RESUMO

OBJECTIVES: Fibromyalgia (FM) is the most common chronic pain disease in middle-aged women. Patients may also complain of migraine, irritable bowel syndrome and depression, which seriously affect their work and life, causing huge economic losses to society. However, the pathogenesis of FM is still controversial and the effect of the current treatment is far from satisfactory. METHODS: Differentially expressed genes (DEGs) and miRNAs (DEMs) were found between FM and normal blood samples. The pathway and process enrichment analysis of the genes were performed. Protein-protein interaction network were constructed. Hub genes were found and analysed in The Comparative Toxicogenomics Database. RESULTS: A total of 102 genes were up-regulated and 46 down-regulated, 206 miRNAs down-regulated, and 15 up-regulated in FM. CD38, GATM, HDC, FOS were found as canditate genes. These genes were significantly associated with musculoskeletal disease, mental disorder, immune system disease. There was partial overlap between metformin therapy-related genes and FM-related genes. CONCLUSIONS: We found DEGs and DEMs in FM patients through bioinformatics analysis, which may be involved in the occurrence and development of FM and serve as potential targets for diagnosis and treatment.

14.
Pharm Stat ; 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32061188

RESUMO

Phase II clinical trials designed for evaluating a drug's treatment effect can be either single-arm or double-arm. A single-arm design tests the null hypothesis that the response rate of a new drug is lower than a fixed threshold, whereas a double-arm scheme takes a more objective comparison of the response rate between the new treatment and the standard of care through randomization. Although the randomized design is the gold standard for efficacy assessment, various situations may arise where a single-arm pilot study prior to a randomized trial is necessary. To combine the single- and double-arm phases and pool the information together for better decision making, we propose a Single-To-double ARm Transition design (START) with switching hypotheses tests, where the first stage compares the new drug's response rate with a minimum required level and imposes a continuation criterion, and the second stage utilizes randomization to determine the treatment's superiority. We develop a software package in R to calibrate the frequentist error rates and perform simulation studies to assess the trial characteristics. Finally, a metastatic pancreatic cancer trial is used for illustrating the decision rules under the proposed START design.

15.
Artigo em Inglês | MEDLINE | ID: mdl-32000495

RESUMO

Surface passivation is a widely used approach to promote the efficiency and stability of perovskite solar cells (PSCs). In the present project, a series of new organic surface passivation molecules, which contain the same triphenylamino group with the hole transfer material of PSCs, have been synthesized. These new passivation molecules are supposed to have both "carrier transfer" capability and "defect passivation" potential. We find that, by using N-((4-(N,N,N-triphenyl)phenyl)ethyl)ammonium bromide (TPA-PEABr) as a surface passivation molecule, the efficiency of the PSCs can be improved from 16.69 to 18.15%, mainly due to an increased Voc (1.09 V compared with 1.02 V in control devices). The increased Voc is due to the reduced surface defect density and a better alignment for the related energy levels after introducing the TPA-PEABr molecules. Moreover, the stability of the PSCs can be significantly improved in TPA-PEABr passivated devices due to the hydrophobic nature of TPA-PEABr. Our results successfully demonstrate that passivation of the perovskite surface with a carefully designed multifunctional small organic molecule should be a useful approach for more stable PSCs with high efficiency.

16.
Eur Spine J ; 29(3): 387-395, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31897731

RESUMO

PURPOSE: Existing automated spine alignment is based on original X-rays that are not applicable for teleradiology for spinal deformities patients. We aim to provide a novel automated vertebral segmentation method enabling accurate sagittal alignment detection, with no restrictions imposed by image quality or pathology type. METHODS: A total of 428 optical images of original sagittal X-rays taken by smartphones or screenshots for consecutive patients attending our spine clinic were prospectively collected. Of these, 300 were randomly selected and their vertebrae were labelled with Labelme. The ground truth was specialists measured sagittal alignment parameters. Pre-trained Mask R-CNN was fine-tuned and trained to predict the vertebra level(s) on the remaining 128 testing cases. The sagittal alignment parameters including the thoracic kyphosis (TK), lumbar lordosis (LL) and sacral slope (SS) were auto-detected, based on the segmented vertebra. Dice similarity coefficient (DSC) and mean intersection over union (mIoU) were calculated to evaluate the accuracy of the predicted vertebra. The detected sagittal alignments were then quantitatively compared with the ground truth. RESULTS: The DSC was 84.6 ± 3.8% and mIoU was 72.1 ± 4.8% indicating accurate vertebra prediction. The sagittal alignments detected were all strongly correlated with the ground truth (p < 0.001). Standard errors of the estimated parameters had a small difference from the specialists' results (3.5° for TK and SS; 3.4° for LL). CONCLUSION: This is the first study using fine-tuned Mask R-CNN to predict vertebral locations on optical images of X-rays accurately and automatically. We provide a novel alignment detection method that has a significant application on teleradiology aiding out-of-hospital consultations. These slides can be retrieved under Electronic Supplementary Material.

17.
Anal Chem ; 92(4): 3426-3433, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31964141

RESUMO

Generally, 3,3',5,5'-tetramethylbenzidine (TMB) cannot react with hydrogen peroxide (H2O2) in neutral pH or in water at room temperature and pressure. Herein, we found that hexavalent chromium (Cr6+) can trigger TMB reacting with H2O2 (TMB-H2O2) in ultrapure water along with a weak signal output. Then, to implement signal amplification effectively, we designed a ternary nanohybrid material containing graphene oxide (GO) nanosheets, gold nanoparticles (Au NPs), and hyperbranched polyethylenimine (PEI) to form rGO/PEI/Au nanohybrids via chemical bonding. After addition of a trace amount of Cr6+, rGO/PEI/Au nanohybrids can effectively catalyze TMB-H2O2 in ultrapure water; thus, a visual chemosensor and electronic spectrum quantitative analysis method for Cr6+ based on chromium-stimulated peroxidase mimetic activity of rGO/PEI/Au nanohybrids were established. The visual chemosensor exhibits excellent selectivity and interference immunity against 34 other interfering substances with a detection limit as low as 2.14 nM. The visual chemosensor for Cr6+ with a low detection limit and high selectivity is expected to have a potential application in environmental analysis, monitoring, and human health maintenance.

18.
Ecotoxicol Environ Saf ; 191: 110231, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31981954

RESUMO

Cadmium (Cd), a common environmental toxic contaminant, is easily accumulated in living organisms, leading to numerous harmful effects. Chlamydomonas reinhardtii, a unicellular eukaryotic green algae strain, is a very suitable candidate for bioremediation of Cd-contaminated water. However, for the poor resistance to Cd, application of C. reinhardtii was restricted and genes mediating Cd tolerance in C. reinhardtii remain unclear. In this paper, adaptive laboratory evolution was performed with algae constant exposure to Cd over 420-day at environmentally relevant concentrations to select C. reinhardtii strains with high tolerance to Cd. Physiological indicators, such as cell proliferation, photosynthetic pigment contents and photosynthetic activity of photosystem were detected to evaluate the Cd tolerance of selected algae strain ALE0.5. Then, whole-genome re-sequencing and transcriptome were applied to identify the genes related to Cd tolerance. Genes involved in photosynthesis (PSBP1), glutathione metabolism (CHLREDRAFT_167073, GPX5) and calcium transport (CHLREDRAFT_189266, CHLREDRAFT_191203, CHLREDRAFT_187187, CSE1) were related to Cd tolerance in C. reinhardtii. This study provides a basis for obtaining transgenic C. reinhardtii strains with high Cd tolerance used for bioremediation of Cd pollution in the future.

19.
Spine (Phila Pa 1976) ; 45(6): E346-E351, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31574056

RESUMO

STUDY DESIGN: Case report. OBJECTIVE: To report a unique mechanical failure of magnetically controlled growing rods (MCGRs) that is related to continuous rod slippage. SUMMARY OF BACKGROUND DATA: Despite the growing popularity of MCGR in the management of patients with early onset scoliosis, postoperative complications and reoperations are not uncommon. Unique complications or unplanned reoperations are observed in patients with MCGRs that are not seen in traditional growing rods. The complications include rod slippage, mismatch between targeted and achieved distraction length, metallosis, and actuator pin fracture. We have identified an unreported failure mechanism whereby deformed threads occur in the internal distraction mechanism of the MCGR. This phenomenon may indicate increased MCGR internal screw friction and increased distraction resistance. Increased friction and resistance ultimately led to distraction failure and revision surgery. METHODS: A girl with early onset scoliosis (EOS) was treated by dual MCGRs. She developed proximal junctional kyphosis (PJK) and continuous rod slippage. Distractions in the out-patient clinic and under sedation did not achieve successful rod lengthening. A tell-tale "crooked rod" radiological sign was identified by angulation between the actuator and the extendable portion of the rod. RESULTS: Rod exchange was performed and she is now 2 years after revision surgery with successful lengthening episodes. Upon review of the extracted MCGR, distraction was not possible even after rod removal and was only resumed after the screw was manually reinserted along its correct threads. CONCLUSION: Deformed threads is a complication that cannot be reverted without rod removal and exchange. Users should be aware of this potential failure mechanism and proceed to early rod exchange rather than attempting any further distractions. LEVEL OF EVIDENCE: 4.

20.
Bioresour Technol ; 297: 122455, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31780242

RESUMO

The denitrification process is crucial for biological nitrogen removal in wastewater treatment plants (WWTPs). In this study, the nitrogen removal efficiency in full-scale WWTPs with different treatment processes and influent characteristics was investigated. The results indicated that the average total nitrogen removal rate (NRR) and denitrification rate in the A/O or A2/O systems were 67.5% and 2.08 mg N h-1 gMLVSS-1, respectively. However, cyclic activated sludge systems (CASSs) showed more efficient nitrogen removal with an average NRR and denitrification rate of 79.6% and 9.89 mg N h-1 gMLVSS-1, respectively. The microbial communities in WWTPs with similar influent compositions were similar and mainly shaped by BOD5. Candidatus Competibacter, Caldilineaceae and Anaerolineaceae were the functional genera closely associated with nitrogen removal based on high-throughput sequencing and correlation analysis. This study provides new insights into the regulation and amelioration of full-scale WWTPs to meet the increasingly stringent nitrogen discharge standard.


Assuntos
Desnitrificação , Águas Residuárias , Reatores Biológicos , Nitrogênio , Esgotos , Eliminação de Resíduos Líquidos
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