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1.
J Nanosci Nanotechnol ; 20(4): 2045-2054, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492211

RESUMO

In this work, green-emission carbon dots (CDs) were prepared for detecting mercury ions (Hg(II)) and iodine ions via a facile hydrothermal method using ethylenediamine and methyl red as nitrogen and carbon sources, respectively, without any other complex reagents. The bacteriostasis experiment showed that the CDs were not toxic to the growth of four kinds of bacteria: Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), which indicated that the CDs had good security and could be used for analysis and detection. The CDs exhibited excitation-independent emission, the fluorescence of which could be quenched by Hg(II), and could be recovered by iodine ions. An approach was established to detect Hg(II) based on the fluorescence quenching of CDs by the synergistic action of a photo induced electron transfer (PET) mechanism, and iodine ions were detected based on the fluorescence recovery of CDs by a HgI2 precipitate formation mechanism. The detection limits for Hg(II) and iodine reached 0.89 µM and 0.50 µM, respectively. Compared to most methods, the method mentioned in this paper has good selectivity, a wider linear range, a lower detection limit and higher security. The synthesized CDs could be probes for sensing Hg(II) and iodine ions.

2.
Biomed Pharmacother ; 120: 109487, 2019 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-31577975

RESUMO

Heart failure (HF) leads to an increase in morbidity and mortality globally. Disorders of energy metabolism and apoptosis of cardiomyocytes are critically involved in the progression of HF. Ginsenoside Rb3 (G-Rb3) is a natural product derived from ginseng that has cardio-protective effect. The pharmacological mechanism of G-Rb3 in the treatment of HF remains to be clarified. In this study, we aimed to explore the regulative effects of G-Rb3 on fatty acids oxidation and apoptosis by in vivo and in vitro studies. Myocardial infarction (MI)-induced HF mice model and a cellular H9C2 injury model was induced by oxygen-glucose deprivation/reperfusion (OGD/R) stimulation. The results showed that G-Rb3 could protect heart functions in MI-induced HF model. G-Rb3 treatment up-regulated expressions of key enzymes involved in ß-oxidation of fatty acids, including carnitine palmitoyltransterase-1α (CPT-1α), acyl-CoA dehydrogenase long chain (ACADL) and the major mitochondrial deacetylase enzyme sirtuin 3 (SIRT3). The upstream transcriptional regulator, peroxisome proliferator-activated receptor α (PPARα), was also up-regulated by G-Rb3 treatment. In vitro study demonstrated that G-Rb3 could protect mitochondrial membrane integrity and exert anti-apoptotic effects, in addition to regulating fatty acids oxidation. Impressively, after cells were co-treated with PPARα inhibitor, the regulative effects of G-Rb3 on energy metabolism and apoptosis were abrogated. Our study suggests that G-Rb3 is a promising agent and PPARα is potential target in the management of HF.

3.
Environ Technol ; : 1-11, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31587596

RESUMO

This paper demonstrates the successful synthesis of TiO2 with (001) crystal plane; its morphology and structure were characterized using XRD, TEM and Raman spectrometer. The results showed that TiO2 nanosheets were bounded by (001) facets on both the top and bottom. TiO2-001/UV photocatalytic process was proved to be a powerful method for degrading tri(chloro-propyl) phosphate (TCPP) in aqueous solution. Under the given parameters, 95% of TCPP was removed in 360 min. The photodegradation followed the pseudo-first-order kinetic reaction. The reactive species during photocatalytic oxidation of TiO2-001 was mainly hydroxyl radical. TCPP was decomposed into small molecule organics by hydroxyl radicals, along with the release of PO43- and Cl-, and most of these intermediates were eventually degraded into carbon dioxide and water.

4.
Biomed Pharmacother ; 120: 109470, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31590124

RESUMO

Fufang Xueshuantong (FXST), a Chinese patent medicine, is composed of Panax notoginseng, Salviae miltiorrhizae, Astragali Radix and Radix Scrophulariae and has been found to prevent diabetic retinopathy. Yes-associated protein (YAP) participates in the pathophysiology of retinal disease and promotes endothelial cell proliferation and angiogenesis. Although it is known that YAP activity is altered by FXST, the role of YAP in mediating the effect of FXST remains unclear. In high glucose-treated retinal vascular endothelial cells (RVECs), FXST significantly reduced cell viability, the number of migrating cells and tube length in the present study. Moreover, FXST decreased the levels of YAP mRNA and protein and inhibited the expression of vascular endothelial growth factor (VEGF). Transfection of sh-YAP into the cells decreased the ability of FXST to modulate cell migration and tube formation. The effect of FXST on VEGF expression was also decreased. Similar results were obtained when the cells were stimulated with a YAP inhibitor in combination with FXST. Thus, FXST is shown to protect high glucose-injured RVECs via YAP-mediated effects.

5.
J Am Heart Assoc ; 8(20): e012052, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31595836

RESUMO

Background The impact of estimated glomerular filtration rate (eGFR) on clinical short-term outcomes after stroke thrombolysis with tissue plasminogen activator remains controversial. Methods and Results We analyzed 18 320 ischemic stroke patients who received intravenous tissue plasminogen activator at participating hospitals in the Chinese Stroke Center Alliance between June 2015 and November 2017. Multivariate logistic regression models were used to evaluate associations between eGFR (<45, 45-59, 60-89, and ≥90 mL/min per 1.73 m2) and in-hospital mortality and symptomatic intracerebral hemorrhage, adjusting for patient and hospital characteristics and the hospital clustering effect. Of the 18 320 patients receiving tissue plasminogen activator, 601 (3.3%) had an eGFR <45, 625 (3.4%) had an eGFR 45 to 59, 3679 (20.1%) had an eGFR 60 to 89, and 13 415 (73.2%) had an eGFR ≥90. As compared with eGFR ≥90, eGFR values <45 (6.7% versus 0.9%, adjusted odds ratio, 3.59; 95% CI, 2.18-5.91), 45 to 59 (4.0% versus 0.9%, adjusted odds ratio, 2.00; 95% CI, 1.18-3.38), and 60 to 89 (2.5% versus 0.9%, adjusted odds ratio, 1.67; 95% CI, 1.20-2.34) were independently associated with increased odds of in-hospital mortality. However, there was no statistically significant association between eGFR and symptomatic intracerebral hemorrhage. Conclusions eGFR was associated with an increased risk of in-hospital mortality in acute ischemic stroke patients after treatment with tissue plasminogen activator. eGFR is an important predictor of poststroke short-term death but not of symptomatic intracerebral hemorrhage.

6.
Nanoscale ; 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31595921

RESUMO

Lithium-ion sulfur batteries as a new energy storage system with high capacity and enhanced safety have been emphasized, and their development has been summarized in this review. The lithium-ion sulfur battery applies elemental sulfur or lithium sulfide as the cathode and lithium-metal-free materials as the anode, which can be divided into two main types. One is anode-type, where elemental sulfur is applied as the cathode, and the anode provides lithium ions. The other one is cathode-type, where lithium sulfide as the cathode provides lithium ions, and lithium-metal-free materials (e.g., graphite, silicon/carbon) function as the anode. Recently, some new lithium-ion sulfur battery systems have also been proposed, and are discussed in this review as well. The lithium-ion sulfur batteries not only maintain the advantage of high energy density because of the high capacities of sulfur and lithium sulfide, but also exhibit the improved safety of the batteries due to a non-lithium-metal in the anode. This review paper aims to track the recent progress in the development of lithium-ion sulfur batteries and summarize the challenges and the approaches for improving their electrochemical performances, including the lithiation methods to prepare lithium-metal-free anodes in anode-type lithium-ion sulfur batteries and the lithium sulfide cathode modification approaches in cathode-type lithium-ion sulfur batteries. Furthermore, the challenges and perspectives for future research and commercial applications have also been enumerated.

7.
J Am Chem Soc ; 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31596081

RESUMO

Semi-hydrogenation of alkynes to alkenes represents a fundamentally useful transformation. In addition to the well-known cis- and trans-semi-hydrogenation, herein a geminal semi-hydrogenation of internal alkynes featuring 1,2-migration is described, which provides new access to the useful terminal vinylsilanes. This process also presents a new mode of reactivity of silyl alkynes. With the proper choice of the cationic [CpRu(MeCN)3]PF6 catalyst and a suitable silyl group, both aryl- and alkyl-substituted silyl alkynes can participate in this highly efficient gem-selective process. Furthermore, dedicated condition optimization also allowed switching of selectivity from gem to trans by using a combination of parameters, including the suitable silyl group, additive and H2 pressure. A systematic DFT study on the reaction mechanism revealed that the formation of the gem-H2 Ru-carbene might be the key intermediate in both gem- and trans-addition reactions, rather than the Ru-vinylidene intermediate. The DFT results were further supported by carefully designed control experiments. This uncommon gem-addition combined with 1,2-silyl migration in the metal-carbene intermediate should open up a new synthetic avenue for alkyne transformations.

8.
Cell Death Dis ; 10(10): 744, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31582720

RESUMO

We investigated the mechanism underlying the effect of a combination treatment of 125I radioactive seed implantation and lobaplatin (LBP) in hepatocellular carcinoma. The effects of administration of HCC cells and subcutaneous tumor model of mice with different doses of 125I or a sensitizing concentration of LBP alone, or in combination, on cellular apoptosis and proliferation were analyzed and it was confirmed that LBP promotes 125I-induced apoptosis and inhibition of proliferation of HCC. Furthermore, isobaric tag for relative and absolute quantification labeling analyses suggested that 125I promoted the apoptosis and inhibition of proliferation of HCC cells by upregulating the expression of PERK-eIF2α-ATF4-CHOP pathway, a well-known apoptosis-related pathway. Moreover, LBP was found to boost the 125I-induced upregulation of this pathway and increase the apoptosis. Our data indicate that LBP promotes the apoptotic and anti-proliferative effects of 125I and provide a firm foundation for better clinical application of this combination therapy.

9.
J Ovarian Res ; 12(1): 92, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601255

RESUMO

AB209371 gene has been characterized as an oncogenic lncRNA in liver cancer. However, its involvement in ovarian carcinoma (OC) is unknown. In the present study, we analyzed the roles of AB209371 in OC. We found that AB209371 gene and Survivin gene were up-regulated in OC and positively correlated with OC development. AB209371 over-expression led to up-regulated Survivin in OC cells, while Survivin over-expression failed to affect AB209371. In addition, AB209371 over-expression led to down-regulated miR-203. However, miR-203 over-expression failed to affect AB209371, but down-regulated the expression of Survivin. In addition, over-expressions of AB209371 and Survivin resulted in the increased proliferation rate of OC cells. Over-expression MiR-203 played the opposite role and attenuated the effects of AB209371 over-expression. Therefore, AB209371 may down-regulate miR-203 to up-regulate Survivin, thereby promoting OC cell proliferation. Our study provided novel insights into the pathogenesis of OC.

10.
Nat Commun ; 10(1): 4613, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601804

RESUMO

Characterizing and interpreting heterogeneous mixtures at the cellular level is a critical problem in genomics. Single-cell assays offer an opportunity to resolve cellular level heterogeneity, e.g., scRNA-seq enables single-cell expression profiling, and scATAC-seq identifies active regulatory elements. Furthermore, while scHi-C can measure the chromatin contacts (i.e., loops) between active regulatory elements to target genes in single cells, bulk HiChIP can measure such contacts in a higher resolution. In this work, we introduce DC3 (De-Convolution and Coupled-Clustering) as a method for the joint analysis of various bulk and single-cell data such as HiChIP, RNA-seq and ATAC-seq from the same heterogeneous cell population. DC3 can simultaneously identify distinct subpopulations, assign single cells to the subpopulations (i.e., clustering) and de-convolve the bulk data into subpopulation-specific data. The subpopulation-specific profiles of gene expression, chromatin accessibility and enhancer-promoter contact obtained by DC3 provide a comprehensive characterization of the gene regulatory system in each subpopulation.

11.
Zhongguo Zhong Yao Za Zhi ; 44(14): 2893-2895, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31602830

RESUMO

The three elements in evidence-based clinical decisions are " best clinical research evidence,physicians' personal experience,and patients' basic values and wishes". This concept coincides with the " bio-psycho-social" model of systematic medicine,and this is the key reason why evidence-based medicine has become the most important diagnostic and therapeutic system under the new medical model. However,there is no methodological support for the implementation of " respecting patients' basic values and wishes".As a result,this concept is difficult to be implemented in clinical practice,and has become the form of " patient or family member' s signature for consent". In narrative medicine,doctors are advocated to record details,psychological processes and even family members' feelings in non-technical language to form parallel medical records,and the key point is to achieve " empathy" between doctors and patients. This idea is consistent with traditional Chinese medicine( TCM),and also provides a practical operation method " to respect patients' basic values and wishes". Medicine is a discipline based on human science,with dual attributes of science and humanity. Humanistic care is the tradition of TCM,and also is one of the basic characteristics and core connotations in TCM. Therefore,in the development of evidence-based TCM,we should combine evidence-based medicine with narrative medicine,and inject humanistic care into evidence-based medicine with the concept and methodology of narrative medicine,so as to achieve the deep integration of science and humanity.

12.
Zhongguo Zhong Yao Za Zhi ; 44(14): 2943-2946, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31602837

RESUMO

Hugan Tablets is a Chinese patent medicine,it has the function of anti-inflammation and reducing transaminase. Based on questionnaire investigation of doctors and a systematic review of research literature on Hugan Tablets,using international clinical practice guidelines' developing methods,with the best available evidence and fully combining expert experience,and following the principle of " evidence-based,consensus-based and experience-based",Expert consensus statement on Hugan Tablets in clinical practice was developed by more than 30 multidisciplinary experts from the nationwide,aimed at guiding and standardizing the rational use of Hugan Tablets by clinicians and to improve clinical efficacy and safety. The expert consensus adopts internationally recognized recommendation criteria for classification of evidence: GRADE. The formation of expert consensus adopts the nominal group technique. Six main considerations are quality of evidence,curative effect,safety,economical efficiency,patient acceptability and other factors. If there is sufficient evidence,a " recommendation" is formed,using GRADE grid voting rule. If there isn' t sufficient evidence,a " consensus opinion" is formed,using majority counting rule. Focus on the indication,usage and dosage,drug use in special population and safety of Hugan Tablets,two recommendations and eight consensus opinions were put forward. Through expert meetings and correspondence,a nationwide consultation and peer review was conducted. This consensus applies to clinicians in hospitals and grass-roots health services,to provide guidance and reference for the rational use of Hugan Tablets.

13.
Zhongguo Zhong Yao Za Zhi ; 44(17): 3773-3779, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31602952

RESUMO

The aim of this paper was to explore the mechanism of Shenxiong Glucose Injection antagonizing apoptosis of H9 c2 cells induced by H_2O_2. H9 c2 cells were pretreated with 1. 7%,3. 4% and 6. 8% Shenxiong Glucose Injection,and then H_2O_2 was introduced to induce apoptosis in vitro. Cell viability was detected by MTS assay,morphological changes of apoptosis were observed by AO/EB fluorescence staining,apoptosis rate was detected by Annexin/PI method,cell expression profile was detected by gene chip technology,the mRNA of PIK3 CA,Bcl-2,Bax,caspase-3 and GAPDH were detected by qRT-PCR,the protein expression levels of PIK3 CA,AKT,P-AKT,Bcl-2,Bax and caspase-3 were detected by Western blot,and the contents of LDH and MDA were detected by kit. The results showed that Shenxiong Glucose Injection of different concentrations significantly increased the viability of H9 c2 cells treated with H_2O_2( P<0. 01),and reversed H_2O_2-induced apoptosis( P< 0. 01). The microarray experiments showed that 138 genes were altered in H9 c2 cells after treatment with Shenxiong Glucose Injection. The differential expression fold of PIK3 CA associated with PI3 K/AKT pathway was 3. 59. The results of qRT-PCR and Western blot showed that Shenxiong Glucose Injection could down-regulate the mRNA and protein expression levels of caspase-3( P<0. 01),up-regulate the mRNA and protein expression level of PIK3 CA and Bcl-2( P<0. 01),and up-regulate the phosphorylation levels of AKT( P<0. 01) in H_2O_2-treated H9 c2 cells. The protective effect of Shenxiong Glucose Injection on H_2O_2 cells injury was significantly inhibited by LY294002,a PI3 K/AKT pathway inhibitor. The results suggested that Shenxiong Glucose Injection may inhibit H_2O_2-induced H9 c2 cells apoptosis by regulating PI3 K/AKT signaling pathway.

14.
J Vet Sci ; 20(5): e54, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31565897

RESUMO

Brucella is an intracellular pathogen that invades a host and settles in its immune cells; however, the mechanism of its intracellular survival is unclear. Modification of small ubiquitin-related modifier (SUMO) occurs in many cellular activities. E2 conjugating enzyme 9 (Ubc9) is the only reported ubiquitin-conjugating enzyme that links the SUMO molecule with a target protein. Brucella's intracellular survival mechanism has not been studied with respect to SUMO-related proteins and Ubc9. Therefore, to investigate the relationship between Brucella melitensis 16M and SUMO, we constructed plasmids and cells lines suitable for overexpression and knockdown of SUMO1 and Ubc9 genes. Brucella 16M activated SUMO1/Ubc9 expression in a time-dependent manner, and Brucella 16M intracellular survival was inhibited by SUMO1/Ubc9 overexpression and promoted by SUMO1/Ubc9 depletion. In macrophages, Brucella 16M-dependent apoptosis and immune factors were induced by SUMO1/Ubc9 overexpression and restricted by SUMO1/Ubc9 depletion. We noted no effect on the expressions of SUMO1 and Ubc9 in B. melitensis 16M lipopolysaccharide-prestimulated mouse RAW264.7 macrophages. Additionally, intracellular survival of the 16M△VirB2 mutant was lower than that of Brucella 16M (p < 0.05). VirB2 can affect expression levels of Ubc9, thereby increasing intracellular survival of Brucella in macrophages at the late stage of infection. Collectively, our results demonstrate that B. melitensis 16M may use the VirB IV secretion system of Brucella to interact with SUMO-related proteins during infection of host cells, which interferes with SUMO function and promotes pathogen survival in host cells.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31580705

RESUMO

Objectives: Large sample and high-quality evidence to evaluate the preliminary safety of the mobilizations and massage for cervical vertigo are not yet available. Thus, the present study aimed to investigate the comparative effectiveness and preliminary safety of Shi-style cervical mobilizations (SCM) compared with traditional massage (TM) in cervical vertigo patients. Design: A prospective, multicenter, open-label, randomized, controlled clinical trial with a 1:1 allocation ratio. Settings: Five academic medical centers. Subjects: A total of 360 adult patients with a diagnosis of cervical vertigo. Interventions: The patients were randomly allocated to either an SCM (n = 180) or TM (n = 180) group. The patients were treated during six sessions over 2 weeks. The primary outcome was the Dizziness Handicap Inventory (DHI) total scale score, and secondary outcomes included the DHI subscales, Chinese version of the Short-Form 36 Health Survey (CSF-36), and adverse events (AEs). Outcomes were assessed in the short term at 2 weeks, 1 month, and 3 months, and in the intermediate term at 6 months after randomization. Results: Significant changes were observed from the baseline in the DHI total scale and subscales at 2 weeks and 1, 3, and 6 months in both groups (all p < 0.05). However, the differences between the two groups were not significant (all p > 0.05). Furthermore, we noted significant changes from the baseline in SF-36 scores at 2 weeks in both groups (all p < 0.05), whereas CSF-36 scores were not significantly higher in the SCM group (all p > 0.05) compared with the TM group. No serious AEs were reported in either of the two groups. Conclusions: No differences in outcomes were detected between the SCM and TM groups in terms of treatment of cervicogenic dizziness. Efficacy trials are required to determine whether the improvement observed for each treatment was causally related to the interventions.

16.
Langmuir ; 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31581771

RESUMO

Quartz crystal microbalance (QCM) has been used to study how the interfacial layer of an ionic liquid dissolved in a polar oil at low weight percentages responds to changes in applied potential. The changes in surface composition at the QCM gold surface depend on both the magnitude and sign of the applied potential. The time resolved response indicates that the relaxation kinetics are limited by diffusion of ions in the interfacial region, and not in the bulk, since there is no concentration dependence. The measured mass changes cannot only be explained in terms of simple ion exchange; the relative molecular volumes of the ions, and the density changes in response to ion exclusion must be considered. The relaxation behaviour of the potential between the electrodes upon disconnecting the applied potential is more complex than observed for pure ionic liquids, but a measure of the surface charge can be extracted from the exponential decay when the rapid initial potential drop is accounted for. The adsorbed film at the gold surface consists predominantly of ionic liquid despite the low concentration, which is unsurprising given the surtactant-like structures of (some of) the ionic liquid ions. Changes in response to potential correspond to changes in the relative numbers of cations and anions, rather than a change in the oil composition. No evidence for an electric field induced change in viscosity is observed. This work shows conclusively that electric potentials can be used to control the surface composition, even in an oil-based system and paves the way for other ion-solvent studies.

17.
iScience ; 20: 229-236, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31590075

RESUMO

A new strategy for the synthesis of conjugated (E,E)-dienones and (E,E)-dienals via a palladium-catalyzed aerobic γ,δ-dehydrogenation of enones and enals has been developed. The method can be employed in the direct and efficient synthesis of various (E,E)-dienones and (E,E)-dienals, including non-substituted α-, ß-, and γ- and/or δ-substituted (E,E)-dienones and (E,E)-dienals. The protocol is featured by the ready accessibility and elaboration of the starting materials, good functional group compatibility, and mild reaction conditions. Furthermore, the reaction is of complete E,E-stereoselectivity and uses molecular oxygen as the sole clean oxidant.

18.
Small ; : e1903879, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31599122

RESUMO

Covalent triazine frameworks (CTFs) hosting arrays of highly ordered sub-2-nm pores are expected to exhibit unusual nanofluidic behaviors, which may enable important applications such as desalination. Herein, nonequilibrium molecular dynamics simulations are applied to investigate transport of water and ions inside two typical CTFs-CTF-1, and CTF-2-having intrinsic pores of 1.2 and 1.5 nm, respectively. Their monolayers exhibit extremely high water permeance but weak ion rejection. CTF multilayers are then investigated. Transport resistances composed of interior and interfacial contribution are correlated with stacking numbers of CTF monolayers to develop equations of predicting water permeance. It is revealed that both the stacking fashion and the number of CTF monolayers forming multilayers significantly influence permeation and ion rejection. Staggered multilayers exhibit much higher ion rejection than eclipsed ones. Staggered CTF-2 multilayers completely reject ions because the interlayer paths between two adjacent staggered monolayers allow only water molecules to pass through. Importantly, it is predicted from the equations that few-layered staggered CTF-2 multilayers, which can be relatively easily produced by experimental methods, exhibit 100% NaCl rejection and up to 100 times higher permeance than commercial reverse osmosis membranes, implying their great potential as building blocks to prepare next-generation desalination membranes.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31569074

RESUMO

In the spirit of the thin-layer quantization scheme, we give the effective Hamiltonian describing the noninteracting electrons confined to an annular corrugated wire, and find that the geometrically induced potential is considerably influenced by the introduced corrugations. By using numerical calculation, we investigate the eigenenergies and the corresponding eigenstates, and find that the transition energies can be sufficiently improved by adding corrugations. Particularly, the transition energy between the adjacent eigenstates corresponds to energy levels difference based on the wavefunction of annular wire, and the number of the energy levels is equal to the number of corrugations. And the larger magnitude of corrugations is capable of increasing the number of bound states. In addition, the distribution of ground state probability density is reconstructed by the corrugations, and the energy shift is generated.

20.
Hum Brain Mapp ; 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31571320

RESUMO

Machine learning has increasingly been applied to classification of schizophrenia in neuroimaging research. However, direct replication studies and studies seeking to investigate generalizability are scarce. To address these issues, we assessed within-site and between-site generalizability of a machine learning classification framework which achieved excellent performance in a previous study using two independent resting-state functional magnetic resonance imaging data sets collected from different sites and scanners. We established within-site generalizability of the classification framework in the main data set using cross-validation. Then, we trained a model in the main data set and investigated between-site generalization in the validated data set using external validation. Finally, recognizing the poor between-site generalization performance, we updated the unsupervised algorithm to investigate if transfer learning using additional unlabeled data were able to improve between-site classification performance. Cross-validation showed that the published classification procedure achieved an accuracy of 0.73 using majority voting across all selected components. External validation found a classification accuracy of 0.55 (not significant) and 0.70 (significant) using the direct and transfer learning procedures, respectively. The failure of direct generalization from one site to another demonstrates the limitation of within-site cross-validation and points toward the need to incorporate efforts to facilitate application of machine learning across multiple data sets. The improvement in performance with transfer learning highlights the importance of taking into account the properties of data when constructing predictive models across samples and sites. Our findings suggest that machine learning classification result based on a single study should be interpreted cautiously.

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