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2.
Environ Sci Technol ; 55(9): 6476-6484, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33844909

RESUMO

Biomass combustion results in the formation and wide distribution of black carbon (BC) in soils, wherein the dissolved fractions are among the most active components. Although the presence of dissolved black nitrogen (DBN) in BC has been identified, its environmental behavior and implication are not understood. This study investigated the photochemical transformation and catalytic activity of DBN under simulated solar irradiation. DBN is more easily transformed than dissolved BC due to its photoactive heteroaromatic N structure, and the half-life of DBN produced at 500 °C (8.6 h) is two times shorter than that of the dissolved BC counterpart (23 h). Meanwhile, solar irradiation is favorable for the homoaggregation of DBN. During irradiation, DBN generates not only reactive oxygen species (e.g., 1O2, O2-, and •OH) but also reactive nitrogen species (mainly •ON), which account for its higher photocatalytic degradation of bisphenol A than dissolved BC. These findings shed new light on the impact of heteroatoms on the phototransformation and activity of BC as well as cycling of N in terrestrial systems.


Assuntos
Nitrogênio , Fuligem , Carbono , Espécies Reativas de Oxigênio , Solo , Fuligem/análise
3.
Malar J ; 20(1): 199, 2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33902612

RESUMO

BACKGROUND: The aim of this study was to investigate and analyse the characteristics of malaria in Shanghai from 2010 to 2019 and to provide suggestions for areas with a similar elimination process in China in order to prompt development of strategies and interventions in the post-elimination stage. METHODS: This was a cross-sectional study exploring the malaria characteristics during 2010-2019 in Shanghai, China. Malaria data from the Infectious Diseases Information Reporting Management System (IDIRMS) between 2010 and 2012 and data from the Parasitic Diseases Information Reporting Management System (PDIRMS) between 2013 and 2019 were combined for analysis in this study. RESULTS: From 2010 to 2019, a total of 436 malaria cases were reported in Shanghai. Among them, 415 (95.18%) were imported from abroad, 19 (4.36%) were domestically acquired from other provinces, 1 (0.23%) case was caused by blood transfusion, and 1 (0.23%) had a long incubation. Only Plasmodium vivax was found in domestically indigenous cases; Plasmodium falciparum accounted for the largest proportion of imported cases. Domestically acquired cases were only reported in 2010-2011 and 88% occurred in June to September; no significant seasonal difference was observed for imported cases over the 10 years. No local transmission has occurred in Shanghai since 2012. The median interval from fever onset to diagnosis was 3 days. Between 2010 and 2019, among 308 foci, 33 were classified as potential transmission and dispersed in suburb areas (Minhang, Baoshan, Jiading, Pudong, Jinshan, Songjiang, Qingpu, Fengxian, and Chongming). Only Anopheles sinensis was present and the proportion of Anopheles sinensis in different species of mosquitoes under surveillance in Shanghai decreased from 2011 to 2019. CONCLUSIONS: Shanghai faces the challenge of malaria re-establishment caused by imported malaria in the post-elimination stage. Therefore, risk investigation and assessment should be carried out, and receptivity and susceptibility should be assessed for every point of focus. Training should be continued to strengthen facility staff capability, and multisectoral coordination and cooperation need to be conducted efficiently to maintain malaria elimination in Shanghai.

4.
Biomed Res Int ; 2021: 6682932, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33869634

RESUMO

This study is aimed at investigating the awareness of and preferences for oral and long-acting injectable HIV preexposure prophylaxis (PrEP) and their associated factors among men who have sex with men (MSM) at high risk of HIV infection in southern China. A cross-sectional survey was conducted among 603 MSM who were recruited through a cohort study called the T2T Study at three sexual health clinics in Guangzhou, Shenzhen, and Wuxi, China, from 2017 to 2018. We collected information on HIV-negative participants' awareness of and willingness to use PrEP and its potential correlations. Univariate and multivariate logistic regressions were used for data analyses. A total of 550 HIV-negative MSM were enrolled in the study. Less than half of at-risk MSM (43.1%) had heard of PrEP before, and the rate of overall willingness to use PrEP was 65.8%, while MSM were more willing to use daily oral PrEP than long-acting injectable- (LAI-) PrEP (62.2% vs. 38.5%). MSM who had university degrees or above (aOR = 1.55, 95% CI: 1.01-2.37), used condoms during last anal sex (1.52, 1.01-2.29), and tested 3 times or more for HIV (2.45, 1.10-5.47) were more likely to be aware of PrEP. MSM who had use of gay dating apps (1.51, 1.02-2.23), ever participated in HIV- or sexually transmitted disease (STD-) related studies (1.91, 1.24-2.94), and had heard of PrEP (3.06, 2.06-4.54) were more willing to use any regimen of PrEP. MSM at high risk of HIV infection had low awareness of PrEP and moderate willingness to use PrEP. Further studies of the implementation and promotion of PrEP targeting at-risk MSM should be performed.

5.
Artigo em Inglês | MEDLINE | ID: mdl-33878274

RESUMO

Despite their high theoretical energy density, the application of lithium-sulfur batteries is seriously hindered by the polysulfide shuttle and sluggish kinetics, especially with high sulfur loading and under low electrolyte usage. Herein, to facilitate the conversion of lithium polysulfides, nickel-boron (Ni-B) alloy nanoparticles, dispersed uniformly on carbon nanotube microspheres (CNTMs), are used as sulfur hosts for lithium-sulfur batteries. It is demonstrated that Ni-B alloy nanoparticles can not only anchor polysulfides through Ni-S and B-S interactions but also exhibit high electrocatalytic capability toward the conversion of intermediate polysulfide species. In addition, the intertwined CNT microspheres provide an additional conductive scaffold in response to the fast electrochemical redox. The enhanced redox kinetics is beneficial to improve the specific capacity and cycling stability of the sulfur cathode, based on the fast conversion of lithium polysulfides and effective deposition of the final sulfide products. Conclusively, the S/Ni-B/CNTM composite delivers a high specific capacity (1112.7 mAh gs-1) along with good cycle performance under both high sulfur loading (8.3 mg cm-2) and a lean electrolyte (3 µL mgs-1). Consequently, this study opens up a path to design new sulfur hosts toward lithium-sulfur batteries.

6.
AIDS Care ; : 1-8, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33908841

RESUMO

Recent evidence shows that circumcision is associated with lower HIV prevalence among MSM. We assessed the acceptability of circumcision for preventing HIV and that of Shang Ring circumcision (SRC) among men who have sex with men (MSM) in China. 538 adult MSM were recruited from six cities in China between January and March 2019. Participants were surveyed by an online, self-administered questionnaire. The acceptability of circumcision was assessed before and after the potential protective effect of circumcision against HIV was informed, and subsequently men's willingness to undergo SRC was assessed. The level of circumcision was 16.4%. Of 450 uncircumcised MSM, their willingness to be circumcised in the following six months increased significantly from 32.2% to 55.6% after the information session. Three quarters of men who were willing to undergo circumcision accepted SRC. MSM who perceived that circumcision could maintain genital hygiene were more likely to accept circumcision after the information session, whereas those who regarded circumcision as an embarrassing surgery were disinclined to be circumcised. The low circumcision rate, along with its high acceptability in Chinese MSM, suggests a great potential benefit of circumcision intervention if proved effective. SRC might be a popular circumcision procedure in this population.

7.
RNA Biol ; : 1-14, 2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33904383

RESUMO

MicroRNAs (miRNAs) are associated with healing or deteriorating degenerated intervertebral disc (IVD) tissues in spinal cord diseases, including intervertebral disc degeneration (IDD). IDD represents a chronic process of extracellular matrix destruction, but the relevant molecular mechanisms implicated in the regenerative effects of miRNAs are unclear. Here, we investigated the regenerative effects of microRNA-140 (miR-140-3p) in an IDD model induced by annulus needle puncture. Bioinformatics analysis was conducted to identify regulatory factors (KLF5/N-cadherin/MDM2/Slug) linked to miR-140-3p effects in IDD. Mesenchymal stem cells (MSCs) were extracted from degenerated IVD nucleus pulposus (NP), and the expression of miR-140-3p/KLF5/N-cadherin/MDM2/Slug was manipulated to explore their effects on cell proliferation, migration, apoptosis and differentiation. The results showed that miR-140-3p was under-expressed in the degenerated IVD NP, whereas its overexpression alleviated IDD. Mechanistic studies suggested that miR-140-3p targeted KLF5 expression, and high KLF5 expression impeded the migration and differentiation of MSCs. In degenerated IVD NP-derived MSCs, MiR-140-3p-mediated KLF5 downregulation simultaneously elevated N-cadherin expression and transcriptionally inhibited MDM2, thus upregulating Slug expression. The experimental data indicated that miR-140-3p enhanced the proliferation, migration and differentiation of degenerated IVD NP-derived MSCs and repressed their apoptosis. The in vivo validation experiment also demonstrated that miR-140-3p inhibited IDD by modulating the KLF5/N-cadherin/MDM2/Slug axis. Collectively, our results uncovered the regenerative role of miR-140-3p in IDD via regulation of the KLF5/N-cadherin/MDM2/Slug axis, which could be a potential therapeutic target for IDD.

8.
Adv Mater ; : e2008709, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33860581

RESUMO

Ferroelectrics have been demonstrated as excellent building blocks for high-performance nonvolatile memories, including memristors, which play critical roles in the hardware implementation of artificial synapses and in-memory computing. Here, it is reported that the emerging van der Waals ferroelectric α-In2 Se3 can be used to successfully implement heterosynaptic plasticity (a fundamental but rarely emulated synaptic form) and achieve a resistance-switching ratio of heterosynaptic memristors above 103 , which is two orders of magnitude larger than that in other similar devices. The polarization change of ferroelectric α-In2 Se3 channel is responsible for the resistance switching at various paired terminals. The third terminal of α-In2 Se3 memristors exhibits nonvolatile control over channel current at a picoampere level, endowing the devices with picojoule read-energy consumption to emulate the associative heterosynaptic learning. The simulation proves that both supervised and unsupervised learning manners can be implemented in α-In2 Se3 neutral networks with high image recognition accuracy. Moreover, these heterosynaptic devices can naturally realize Boolean logic without an additional circuit component. The results suggest that van der Waals ferroelectrics hold great potential for applications in complex, energy-efficient, brain-inspired computing systems and logic-in-memory computers.

9.
Crit Rev Food Sci Nutr ; : 1-12, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33860692

RESUMO

Ferritin is an important iron storage protein, which is widely existed in all forms of life. Ferritin can regulate iron homeostasis when iron ions are lacking or enriched in the body, so as to avoid iron deficiency diseases and iron poisoning. Ferritin presents a hollow nanocage, which can store ions or other small molecular substances in the cavity. Therefore, ferritin shows its potential as a functional nanomaterial that can deliver nutrients or drugs in a targeted manner to improve bioavailability. Due to the special structure, the research on ferritin has attracted more and more attention in recent years. In this paper, the structural characteristics of ferritin were introduced, and the natural purification and prokaryotic expression methods of ferritin from different sources were described. At the same time, ferritin can bind to small molecules, so that it has the activity of small molecules, to construct a new type of ferritin. As a result, ferritin plays an important role as a nutrient substance, in targeted transport, and disease monitoring, etc. In conclusion, the yield of ferritin can be improved by means of molecular biology. Meanwhile, molecular modification can be used to make ferritin have unique activity and function, which lays a foundation for subsequent research. HighlightsThe molecular and structural properties of ferritins were clearly described.Isolation and purification technologies of ferritin were compared.Characterization, functions and molecular modifications mechanism of ferritin were reviewed.The applications of ferritin in pharmaceutical and food industry were prospected.

10.
J Nat Med ; 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33861415

RESUMO

Infantile hemangioma (IH) is the most common benign vascular tumor resulting from the hyper-proliferation of vascular endothelial cells. In treatment of various tumors including IH, ß-elemene, a compound extracted from Rhizoma zedoariae, has been reported to have anti-tumor effect. However, the underlying mechanisms of ß-elemene in hemangioma have remained uninvestigated. In this presented study, functional analysis showed that low concentrations of ß-elemene promoted the proliferation, migration and tube formation of human hemangioma endothelial cells (HemECs), while high concentrations of ß-elemene produced inhibitory effects. Further, we also found that angiotensin-converting enzyme 2 (ACE2) expression was down-regulated at both mRNA and protein levels, while hypoxia-inducible factor-1 alpha (HIF-1-α) was up-regulated in infantile hemangiomas tissues and HemECs at both mRNA and protein levels. This result suggested that ACE2 and HIF-1-α play roles in IH. ACE2 expression was down-regulated with the treatment of ß-elemene at different dosage point. Interestingly, the expression of Vascular endothelial growth factor-A (VEGFA) increased with treatment of low concentrations of ß-elemene in HemECs, in contrary, the expression of VEGFA expression decreased with treatment of high concentrations of ß-elemene. Moreover, if the concentration of ß-elemene reached 40 µg/ml or higher, the expression of HIF-1-α decreased. Taken together, our data indicated that the different effects of ß-elemene on the proliferation, migration and angiogenesis of hemangioma at different concentrations: The ACE2 signaling pathway dominates with treatment of low concentrations of ß-elemene, stimulating the expression of downstream VEGFA to promote the angiogenesis of hemangioma; under the condition of high concentrations of ß-elemene, the HIF-1-α signaling pathway inhibits the expression of VEGFA and further inhibits the angiogenesis of hemangioma.

11.
ACS Nano ; 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33829760

RESUMO

Transition metal dichalcogenides (TMDs) represent a class of semiconducting two-dimensional (2D) materials with exciting properties. In particular, defects in 2D-TMDs and their molecular interactions with the environment can crucially affect their physical and chemical properties. However, mapping the spatial distribution and chemical reactivity of defects in liquid remains a challenge. Here, we demonstrate large area mapping of reactive sulfur-deficient defects in 2D-TMDs in aqueous solutions by coupling single-molecule localization microscopy with fluorescence labeling using thiol chemistry. Our method, reminiscent of PAINT strategies, relies on the specific binding of fluorescent probes hosting a thiol group to sulfur vacancies, allowing localization of the defects with an uncertainty down to 15 nm. Tuning the distance between the fluorophore and the docking thiol site allows us to control Föster resonance energy transfer (FRET) process and reveal grain boundaries and line defects due to the local irregular lattice structure. We further characterize the binding kinetics over a large range of pH conditions, evidencing the reversible adsorption of the thiol probes to the defects with a subsequent transitioning to irreversible binding in basic conditions. Our methodology provides a simple and fast alternative for large-scale mapping of nonradiative defects in 2D materials and can be used for in situ and spatially resolved monitoring of the interaction between chemical agents and defects in 2D materials that has general implications for defect engineering in aqueous condition.

12.
Animals (Basel) ; 11(3)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800204

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the important antibiotic resistant pathogens causing infections in humans and animals. The increasing observation of MRSA in wildlife species has raised the concern of its impact on animal health and the potential of zoonotic transmission. This study investigated the prevalence of S. aureus in fecal samples from non-human primates in a zoo located in Jiangsu, China, in which 6 out of 31 (19.4%) fecal samples, and 2 out of 14 (14.3%) indoor room floor swab samples were S. aureus-positive. The antibiotic susceptibility tests of the eight isolates showed that the two isolates were resistant to both penicillin and cefoxitin, the three isolates were resistant only to penicillin, while three isolates were susceptible to all detected antibiotics. The two isolates resistant to cefoxitin were further identified as MRSA by the presence of mecA. Five different spa types were identified including t034 of two MRSA isolates from Trachypithecus francoisi, t189 of two methicillin-susceptible S. aureus (MSSA) isolates from Rhinopithecus roxellana, t377 of two MSSA isolates from Colobus guereza, and two novel spa types t19488 and t19499 from Papio anubis. Whole genome sequencing analysis showed that MRSA t034 isolates belonged to ST398 clustered in clonal complex 398 (CC398) and carried the type B ΦSa3 prophage. The phylogenetic analysis showed that the two MRSA t034/ST398 isolates were closely related to the human-associated MSSA in China. Moreover, two MRSA isolates contained the virulence genes relating to the cell adherence, biofilm formation, toxins, and the human-associated immune evasion cluster, which indicated the potential of bidirectional transfer of MRSA between monkeys and humans. This study is the first to report MRSA CC398 from monkey feces in China, indicating that MRSA CC398 could colonize in monkey and have the risk of transmission between humans and monkeys.

13.
Food Chem ; 356: 129655, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33831832

RESUMO

Phosphorylation of myosin regulatory light chain (MRLC) can regulate muscle contraction and thus affect actomyosin dissociation and meat quality. The objective of this study was to explore the mechanism by how MRLC phosphorylation regulates actomyosin dissociation and thus develop strategies for improving meat quality. Here, the phosphorylation status of MRLC was modulated by myosin light chain kinase and myosin light chain kinase inhibitor. MRLC phosphorylation at Ser17 decreased the kinetic energy and total energy of actomyosin, thus stabilized the structure, facilitating the interaction between myosin and actin; this was one possible way that MRLC phosphorylation at Ser17 negatively affects actomyosin dissociation. Moreover, MRLC phosphorylation at Ser17 was beneficial to the formation of ionic bonds, hydrogen bonds, and hydrophobic interaction between myosin and actin, and was the second possible way that MRLC phosphorylation at Ser17 negatively affects actomyosin dissociation.

14.
Food Funct ; 12(9): 4176-4198, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33861291

RESUMO

Herein, polyphenols were extracted from Pinus koraiensis bark and characterized. Besides, the in vitro antioxidant activity, inhibition effect on cancer cells and the activity of the immune system were investigated. The results showed that the main component of Pinus koraiensis bark was 3,5,7,3',5'-pentahydroxydihydroflavone. PKB polyphenols demonstrated a high antioxidant activity during in vitro investigation. In vivo immunological function studies on oxidatively injured mice revealed that Pinus koraiensis bark polyphenols effectively improved the survival status of irradiated mice. PKBP also increased the spleen and thymus index of mouse immunoregulatory organs. The results indicated that the phagocytic ability of mononuclear macrophages was increased. Comparing the cell distribution of the PKBP administered group and the model group, the PKBP-administered group reduced the cells arrested in the G1 phase, while the number of cells increased in the S and G2 phases. PKBP effectively protected the mouse immune system and reduced the immune suppression caused by radiation. These findings also confirmed that oxidative damaged cells induced by radiation could be repaired. PKBP had the highest inhibitory activity on colon cancer cells HT29, breast cancer cells MFC-7, gastric cancer cells BGC-823 and cervical cancer HeLa and HT29 cancer cells. PKB polyphenols could effectively induce the production of DNA-Ladder fragments and cause DNA damage in cancer cells. PKBP also blocked the cycle of cancer cells in the G2 phase, stopped cell division and induced cancer cell apoptosis. Analysis of cell apoptosis by Annexin V-FTIC/PI double staining indicated that PKBP inhibited HT29 cancer cell proliferation.

15.
Org Lett ; 23(6): 2147-2152, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33662211

RESUMO

Mizoroki-Heck reaction of unstrained aryl ketone with acrylate/styrene is accomplished via palladium-catalyzed ligand-promoted C-C bond cleavage. Various (hetero)aryl ketones are compatible in the reaction, affording the alkene product in good to excellent yields. Further applications in the late-stage olefination of some drugs, natural products, and fragrance-derived aryl ketones demonstrate the synthetic utility of this protocol. By employing ketone as both the directing group and the leaving group, 1,2-bifunctionalization is achieved via sequential ortho-C-H alkylation/ipso-Heck olefination.

16.
Adv Mater ; : e2007503, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33739570

RESUMO

Emergent phenomena such as unconventional superconductivity, Mott-like insulators, and the peculiar quantum Hall effect in graphene-based heterostructures are proposed to stem from the superlattice-induced renormalization of (moiré) Dirac fermions at the graphene Brillouin zone corners. Understanding the corresponding band structure commonly demands photoemission spectroscopy with both sub-meV resolution and large-momentum coverage, beyond the capability of the current state-of-the-art. Here the realization of moiré Dirac cones around the Brillouin zone center in monolayer In2 Se3 /bilayer graphene heterostructure is reported. The renormalization is evidenced by reduced Fermi velocity (≈23%) of the moiré Dirac cones and the reshaped Dirac point at the Γ point where they intersect. While there have been many theoretical predictions and much indirect experimental evidence, the findings here are the first direct observation of Fermi velocity reduction of the moiré Dirac cones. These features suggest strong In2 Se3 /graphene interlayer coupling, which is comparable with that in twisted bilayer graphene. The strategy expands the choice of materials in the heterostructure design and stimulates subsequent broad investigations of emergent physics at the sub-meV energy scale.

17.
Sci Total Environ ; 778: 146378, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33725595

RESUMO

Silicon, in its nanoscale form, has shown plant-promoting and insecticidal properties. To date, however, we lack mechanistic evidence for how nanoscale silicon influences the regulation of plant chemical defenses against herbivore attacks. To address this gap, we compared the effect of Si nanodots (NDs) and sodium silicate, a conventional silicate fertilizer, on maize (Zea mays L.) chemical defenses against the oriental armyworm (Mythimna separata, Walker) caterpillars. We found that Si NDs and sodium silicate additions, at the dose of 50 mg/L, significantly inhibited the growth of caterpillars by 53.5% and 34.2%, respectively. This increased plant resistance was associated with a 44.2% increase in the production of chlorogenic acid, as well as the expression of PAL, C4H, 4CL, C3H and HCT, core genes involved in the biosynthesis of chlorogenic acid, by 1.7, 2.4, 1.9, 1.8 and 4.5 folds, respectively. Particularly, in the presence of M. separata, physiological changes in maize plants treated with 50 mg/L Si NDs, including changes in shoot biomass, leaf nutrients (e.g., K, P, Si), and chemical defense compounds (e.g., chlorogenic acid, total phenolics), were higher than those of plants added with equivalent concentrations of conventional silicate fertilizer. Taken together, our findings indicate that Si, in nanoscale form, could replace synthetic pesticides, and be implemented for a more effective and ecologically-sound management of insect pests in maize crop farming.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33730711

RESUMO

We present a chemical vapor deposition method for the synthesizing of single-crystal 1T'-MoTe2nanowires and the observation of one dimensional weak antilocalization (WAL) effect in 1T'-MoTe2nanowires for the first time. The diameters of the 1T'-MoTe2nanowires can be controlled by changing the flux of H2/Ar carrier gas. Spherical- aberration-corrected transmission electron microscopy (ACTEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDS) reveal the 1T' phase and the atomic ratio of Te/Mo closing to 2:1. The resistivity of 1T'-MoTe2nanowires shows metallic behavior and agrees well with the Fermi liquid theory (< 20 K). The coherence length extracted from 1D Hikami-Larkin-Nagaoka (HLN) model with the presence of strong spin-orbit coupling is proportional to T-0.36, indicating a Nyquist electron-electron interaction dephasing mechanism at one dimension. These results provide a feasible way to prepare one-dimensional topological materials and is promising for fundamental study of the transport properties.

19.
Spine J ; 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33766788

RESUMO

BACKGROUND CONTEXT: Many risk factors for osteoporotic vertebral compression fractures (OVCFs) have been reported. However, there are few reports on the relationship between spine sagittal parameters in patients with osteoporosis. PURPOSE: To explore whether: spinal sagittal imbalance is associated with future vertebral compression fractures in osteoporosis patients; spinal sagittal parameters in patients with osteoporosis can predict the occurrence of vertebral compression fractures. STUDY DESIGN: A retrospective cohort study. PATIENT SAMPLE: Patients with osteoporosis. OUTCOME MEASURES: Occurrence of OVCFs during the follow-up period. METHODS: From January 2017 to October 2019, eligible patients with osteoporosis at the initial visit were enrolled. They were followed up to November 1, 2020. Based on whether OVCFs occurred during the follow-up, the patients were divided into two groups: the experimental group (vertebral compression fracture group) and the control group (no vertebral compression fracture group). Intragroup analysis was performed as follows: Pearson and Spearman correlation coefficients were used to calculate the correlation between each parameter. Intergroup analysis was performed as follows. For categorical variables, the chi-square test was used; for normally distributed continuous variables, an independent sample t-test was used; and for non-normally distributed variables, a two-sample nonparametric test was used. Binary logistic regression analysis and receiver operating characteristic (ROC) curves were used to determine independent risk factors and critical values, respectively. RESULTS: A total of 340 patients with osteoporosis were enrolled. The longest and shortest follow-up periods were 44 months and 12 months, respectively, with an average of 25.2±10.2 months. There were significant differences in age, bone mineral density (femur and lumbar), smoking history, medication treatment regularity, Thoracolumbar Kyphosis (TLK), Pelvic Tilt (PT), C7-S1 Sagittal Vertical Axis (C7-S1 SVA), and C2-7 Sagittal Vertical Axis (C2-7 SVA) between the experimental and control groups. There were no significant differences in sex, body mass index (BMI), alcohol consumption history, hypertension, diabetes, coronary heart disease, family history of osteoporosis, physical activity, Thoracic Kyphosis (TK), Lumbar Lordosis (LL), Pelvic Incidence (PI), Sacral Slope (SS), C2-C7 Cobb Angle (CL), T1 slope (T1S) or blood parameters. Through binary logistic regression analysis, we found that BMD, medication treatment regularity and C7-S1 SVA were independent risk factors for future vertebral compression fractures. According to the ROC curve, the prediction accuracy of C7-S1 SVA was the highest. Through the calculation of critical values, we found that when C7-S1 SVA was more than 3.81 cm, future OVCFs were more likely to occur, and for every 1cm increase in C7-S1 SVA, the incidence of future OVCFs would increase by 0.324 times (p<.001, OR=1.324). Through intragroup analysis, we further found that C7-S1 SVA was positively correlated with the percentage of vertebral body wedging. CONCLUSIONS: For patients with osteoporosis, a C7-S1 SVA more than 3.81cm is significantly associated with a greater risk for vertebral compression fractures in the future.

20.
J Neural Eng ; 18(5)2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33784640

RESUMO

Objective. Steady-state visual evoked potential (SSVEP)-brain-computer interfaces (BCIs) can cause much visual discomfort if the users use the SSVEP-BCIs for a long time. As an alternative scheme to reduce users' visual fatigue, this study proposes a new stimulation paradigm (termed as steady state peripheral visual evoked potential, abbreviated as SSPVEP) which makes full use of peripheral vision. The electroencephalography (EEG) signals are classifiable which means this proposed stimulation paradigm can be used in BCI system with the aid of the latest hybrid signal processing approach.Approach. Under the SSPVEP stimulation paradigm, 20 targets are mounted on 20 frequencies and other targets are set between two targets with flicker stimuli coding. In order to ensure the classification accuracy of SSPVEP signal detection under the proposed stimulation paradigm, two optimization schemes are proposed for the detection stage of the conventional ensemble task-related component analysis (ETRCA) algorithm. The first optimization scheme uses nonlinear correlation coefficient at the detection part for the first time to improve the classification accuracy of the system. The second optimization scheme usesγcorrection to enhance the time domain features of the SSPVEP signals, and uses Manhattan distance for the final detection.Main results. According to the response waveforms of the EEG signals generated under the SSPVEP stimulation paradigm and the results of the questionnaire on user's comfort level to the two stimulation paradigms (SSPVEP paradigm and conventional SSVEP paradigm), the proposed stimulation paradigm brings less visual fatigue. The comparison results indicate that the proposed detection methods (ETRCA +γcorrection + Manhattan distance, ETRCA + Spearman correlation) can greatly improve the classification accuracy compared with the individual template canonical correlation analysis method and conventional ETRCA method based on Pearson correlation.Significance. The SSPVEP stimulation paradigm reduces users' visual fatigue via using peripheral vision, which provides a new design idea for SSVEP stimulation paradigm aimed at visual comfort.

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