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1.
IEEE Trans Med Imaging ; PP2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33945472

RESUMO

Instance segmentation is of great importance for many biological applications, such as study of neural cell interactions, plant phenotyping, and quantitatively measuring how cells react to drug treatment. In this paper, we propose a novel box-based instance segmentation method. Box-based instance segmentation methods capture objects via bounding boxes and then perform individual segmentation within each bounding box region. However, existing methods can hardly differentiate the target from its neighboring objects within the same bounding box region due to their similar textures and low-contrast boundaries. To deal with this problem, in this paper, we propose an object-guided instance segmentation method. Our method first detects the center points of the objects, from which the bounding box parameters are then predicted. To perform segmentation, an object-guided coarse-to-fine segmentation branch is built along with the detection branch. The segmentation branch reuses the object features as guidance to separate target object from the neighboring ones within the same bounding box region. To further improve the segmentation quality, we design an auxiliary feature refinement module that densely samples and refines point-wise features in the boundary regions. Experimental results on three biological image datasets demonstrate the advantages of our method. The code will be available at https://github.com/yijingru/ObjGuided-Instance-Segmentation.

2.
Eur Spine J ; 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33948750

RESUMO

PURPOSE: Biomechanical comparison between rigid and non-rigid posterior stabilization systems following lumbar interbody fusion has been conducted in several studies. However, most of these previous studies mainly focused on investigating biomechanics of adjacent spinal segments or spine stability. The objective of the present study was to compare biomechanical responses of the fusion devices when using different posterior instrumentations. METHODS: Finite-element model of the intact human lumbar spine (L1-sacrum) was modified to simulate implantation of the fusion cage at L4-L5 level supplemented with different posterior stabilization systems including (i) pedicle screw-based fixation using rigid connecting rods (titanium rods), (ii) pedicle screw-based fixation using flexible connecting rods (PEEK rods) and (iii) dynamic interspinous spacer (DIAM). Stress responses were compared among these various models under bending moments. RESULTS: The highest and lowest stresses in endplate, fusion cage and bone graft were found at the fused L4-L5 level with DIAM and titanium rod stabilization systems, respectively. When using PEEK rod for the pedicle screw fixation, peak stress in the pedicle screw was lower but the ratio of peak stress in the rods to yield stress of the rod material was higher than using titanium rod. CONCLUSIONS: Compared with conventional rigid posterior stabilization system, the use of non-rigid stabilization system (i.e., the PEEK rod system and DIAM system) following lumbar interbody fusion might increase the risks of cage subsidence and cage damage, but promote bony fusion due to higher stress in the bone graft. For the pedicle screw-based rod stabilization system, using PEEK rod might reduce the risk of screw breakage but increased breakage risk of the rod itself.

3.
Exp Cell Res ; : 112618, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33965401

RESUMO

Androgenetic alopecia (AGA) is the most common type of hair loss dysfunction. Secreted frizzled related protein 1 (SFRP1) is found to be associated with hair loss, but its role in AGA and the regulation mechanism of its transcription level is unclear. The aim of our study is to explore the expression of SFRP1 in AGA samples and its transcriptional mechanism. Male frontal and occipital scalp hair follicles from AGA patients were collected, and human dermal papilla cells (DPCs) were isolated and cultured. SFRP1 gene was cloned and constructed into recombinant plasmids to perform dual-luciferase reporter assay. Transcription factor binding sites were predicted through the Jaspar website and further confirmed by the chromatin immunoprecipitation (ChIP) assay. Expression of genes in DPCs was determined by immunofluorescence (IF) staining, quantitative real-time PCR (qRT-PCR) and western blotting. Our findings showed that SFRP1 was highly expressed in DPCs of AGA patients. The core promoter region of SFRP1 was from -100 to +50 bp and was found to be positively regulated by forkhead box C1 (FOXC1), a transcription factor related to hair growth, both at mRNA and protein level in DPCs. Our study suggests that FOXC1 plays an important role in regulating SFRP1 transcription, which may provide new insights into the development of therapeutic strategies for the treatment of AGA.

4.
J Hypertens ; 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33967241

RESUMO

OBJECTIVE: To assess the association between the variability of blood pressure (BP) readings within an initial clinic visit, the variability within subsequent visits and the variability between visits over 1 week in a general population. METHODS: This study included 1401 adult residents, who were not taking antihypertensive drugs, having BP measurements at three visits over 1 week. The difference between maximal and minimal BP readings (ΔBP), ΔBP/BPm (the mean BP value in a visit), the standard deviation (SD) and coefficient of variation (coefficient of variation = SD × 100/mean) of three BP values in each visit were used to estimate the within-visit BP variability (BPV). The SD and coefficient of variation of all nine BP readings over the three visits were calculated as SD9 or CV9 to reflect the overall BPV during the study visits. The SD and coefficient of variation on the mean BP values (BPm) of three visits were computed as SD-3 or CV-3, whereas the difference between maximal and minimal BP in three visits was computed as ΔBP-3 to estimate visit-to-visit BPV. The average BP or HR was the mean values of nine BP or HR readings over three visits. RESULTS: The systolic and diastolic mean BP (SBP and DBP) decreased from the first to the third visit. The ΔBP, SD and coefficient of variation for both SBP and DBP at the first visit were positively and significantly correlated with the corresponding variables computed at the second and third visits, as well as with overall BPV (ΔBP9, SD9 and CV9). A positive correlation was also found between overall BPV and visit-to visit BPV (SD-3, CV-3 and ΔBP9). Multivariate analysis showed: no association between average SBP and systolic coefficient of variation or ΔBP/BPm but a negative association between average DBP and coefficient of variation or ΔBP/BPm for DBP at the first visit, DBP-3 and DBP9. Age was positively correlated with coefficient of variation or ΔBP/BPm for SBP at the first visit, SBP-3 and SBP9, and correlated with coefficient of variation and ΔBP/BPm for DBP only at the first visit. CONCLUSION: In a general population, within-visit BPV at an initial visit is associated with within-visit BPV at subsequent visits and with visit-to-visit BPV over three visits within 1 week.

5.
Environ Sci Technol ; 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33944552

RESUMO

Despite recent advancements in photocatalysis enabled by materials science innovations, the application of photocatalysts in water treatment is still hampered due to low overall efficiency. Herein, we present a TiO2 photocatalytic process with significantly enhanced efficiency by the introduction of micro-nano bubbles (MNBs). Notably, the removal rate of a model organic contaminant (methylene blue, MB) in an air MNB-assisted photocatalytic degradation (PCD) process was 41-141% higher than that obtained in conventional macrobubble (MaB)-assisted PCD under identical conditions. Experimental observations and supporting mechanistic modeling suggest that the enhanced photocatalytic degradation is attributed to the combined effects of increased dissolution of oxygen, improved colloidal stability and dispersion of the TiO2 nanocatalysts, and interfacial photoelectric effects of TiO2/MNB suspensions. The maximum dissolved oxygen (DO) concentration of the MNB suspension (i.e., 11.7 mg/L) was 32% higher than that of an MaB-aerated aqueous solution (i.e., 8.8 mg/L), thus accelerating the hole oxidation of H2O on TiO2. We further confirmed that the MNBs induced unique light-scattering effects, consequently increasing the optical path length in the TiO2/MNB suspension by 7.6%. A force balance model confirmed that a three-phase contact was formed on the surface of the bubble-TiO2 complex, which promoted high complex stability and PCD performance. Overall, this study demonstrates the enhanced photocatalytic water decontamination by MNBs and provides the underlying mechanisms for the process.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33958539

RESUMO

STUDY DESIGN: A biomechanical comparison study using finite element (FE) method. OBJECTIVE: To investigate effects of different dynamic stabilization devices, including pedicle-based dynamic stabilization system (PBDSS) and interspinous process spacer (ISP), used for topping-off implants on biomechanical responses of human spine after lumbar interbody fusion. SUMMARY OF BACKGROUND DATA: Topping-off stabilization technique has been proposed to prevent adjacent segment degeneration following lumbar spine fusion. PBDSS and ISP are the most used dynamic stabilizers for topping-off instrumentation. However, biomechanical differences between them still remain unclear. METHODS: A validated, normal FE model of human lumbosacral spine was employed. Based on this model, rigid fusion at L4-L5 and moderately disc degeneration at L3-L4 were simulated and used as a comparison baseline. Subsequently, Bioflex and DIAM systems were instrumented at L3-L4 segment to construct PBDSS-based and ISP-based topping-off models. Biomechanical responses of the models to bending moments and vertical vibrational excitation were computed using FE static and random response analyses, respectively. RESULTS: Results from static analysis showed that at L3-L4, the response parameters including annulus stress and range of motion were decreased by 41.6-85.2% for PBDSS-based model and by 6.3-67% for ISP-based model compared with rigid fusion model. At L2-L3, these parameters were lower in ISP-based model than in PBDSS-based model. Results from random response analysis showed that topping-off instrumentation increased resonant frequency of spine system but decreased dynamic response of annulus stress at L3-L4. PBDSS-based model generated lower dynamic stress than ISP-based model at L3-L4, but the dynamic stress was higher at L2-L3 for PBDSS-based model. CONCLUSIONS: Under static and vibration loadings, the PBDSS-based topping-off device (Bioflex) provided a better protection for transition segment, and likelihood of degeneration of supra-adjacent segment might be relatively lower when using the ISP-based topping-off device (DIAM).Level of Evidence: 5.

8.
Artigo em Inglês | MEDLINE | ID: mdl-33928733

RESUMO

Lithium metal anode holds great promises for next-generation battery technologies but is notoriously difficult to work with. The key to solving this challenge is believed to lie in the ability of forming stable solid-electrolyte interphase (SEI) layers. To further address potential safety issues, it is critical to achieve this goal in nonflammable electrolytes. Building upon previous successes in forming stable SEI in conventional carbonate-based electrolytes, here we report that reversible Li stripping/plating could be realized in triethyl phosphate (TEP), a known flame retardant. The critical enabling factor of our approach was the introduction of oxygen, which upon electrochemical reduction induces the initial decomposition of TEP and produces Li 3 PO 4 and poly-phosphates. Importantly, the reaction was self-limiting, and the resulting material regulated Li plating by limiting dendrite formation. In effect, we obtained a functional SEI on Li metal in a nonflammable electrolyte. When tested in a symmetric Li||Li cell, more than 300 cycles of stripping/plating were measured at a current density of 0.5 mA·cm -2 . Prototypical Li-O 2 and Li-ion batteries were also fabricated and tested to further support the effectiveness of this strategy. The mechanism by which the SEI forms was studied by density functional theory (DFT), and the predictions were corroborated by the successful detection of the intermediates and products.

9.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 35(4): 420-425, 2021 Apr 15.
Artigo em Chinês | MEDLINE | ID: mdl-33855824

RESUMO

Objective: To explore the effectivenesss of simple lateral extensor digitorum communis (EDC) split approach combined with loop-plate fixation in the treatment of ulnar coronoid fracture in terrible triad of elbow (TTE). Methods: The clinical data of 60 patients with TTE who met the selection criteria between January 2015 and May 2018 were retrospectively analyzed. There were 48 males and 12 females, aged from 18 to 60 years (mean, 37.4 years). All the patients were closed fractures. Injury causes included fall injury in 28 cases, falling from height in 20 cases, and traffic accident injury in 12 cases. All patients had no vascular and nerve injury, and the time from injury to operation was 1-14 days, with an average of 4.8 days. The height and size of the fracture of the coronal process were measured by CT and accurate classifications were made. All the 60 patients were treated with simple lateral EDC split approach combined with loop-plate to fix the ulnar coronoid fracture; 20 patients of radial head fracture were fixed with hollow screw, 32 patients with mini-plate fixation, 8 patients with radial head prosthesis replacement; 16 patients with suture and 44 patients with suture anchor to reconstruct lateral collateral ligament complex; 10 patients with residual instability of elbow joint were fixed with hinge external fixator, and others were fixed with adjustable tension brace after operation. Postoperative imaging examination was performed to evaluate fracture healing and complications, such as loosening or breakage of internal fixator, osteoarthritis, and heterotopic ossification, etc. During follow-up, the range of motion (ROM) of the elbow joint was recorded, including elbow flexion, extension, and forearm pronation, supination. Mayo elbow function score system (MEPS) was used to evaluate elbow joint function at last follow-up. Results: All patients were followed up 16-24 months (mean, 20.2 months). All incisions healed by first intention after operation, and no complications such as vascular nerve injury, elbow joint instability, internal fixation failure, and infection occurred; the fracture healing time was 9-17 weeks (mean, 11.7 weeks). Four cases developed elbow stiffness after operation, and all underwent elbow joint lysis with internal fixator removal within 12-15 months after operation; 10 cases developed heterotopic ossification without special treatment. At last follow-up, the ROM of elbow flexion ranged from 85° to 135° (mean, 116°), the ROM of elbow extension ranged from 0° to 20° (mean, 11°), the ROM of forearm pronation ranged from 55° to 75° (mean, 70°), and the ROM of forearm supination ranged from 60° to 90° (mean, 83°). The MEPS score ranged from 55 to 100 (mean, 86.1); the effectiveness were excellent in 40 patients, good in 10 patients, fair in 6 patients, and poor in 4 patients, with an excellent and good rate of 83.3%. Conclusion: The simple lateral EDC split approach is fully exposed, and the loop-plate can fix the ulnar coronoid fractures firmly and stably, which can restore the stability of the elbow joint, and the effectiveness is satisfactory.


Assuntos
Articulação do Cotovelo , Luxações Articulares , Fraturas do Rádio , Fraturas da Ulna , Idoso , Cotovelo , Articulação do Cotovelo/cirurgia , Feminino , Fixação Interna de Fraturas , Humanos , Masculino , Fraturas do Rádio/cirurgia , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento , Fraturas da Ulna/cirurgia
10.
Artigo em Inglês | MEDLINE | ID: mdl-33738519

RESUMO

PURPOSE: To investigate the effects of dose reduction on image quality and lesion detectability of oncological 18F-FDG total-body PET/CT in pediatric oncological patients and explore the minimum threshold of administered tracer activity. METHODS: A total of 33 pediatric patients (weight 8.5-58.5 kg; age 0.8-17.6 years) underwent total-body PET/CT using uEXPLORER scanner with an 18F-FDG administered dose of 3.7 MBq/kg and an acquisition time of 600 s were retrospectively enrolled. Low-dose images (0.12-1.85 MBq/kg) were simulated by truncating the list-mode PET data to reducing count density. Subjective image quality was rated on a 5-point scale. Semi-quantitative uptake metrics for low-dose images were assessed using region-of-interest (ROI) analysis of healthy liver and suspected lesions and were compared with full-dose images. The micro-lesion detectability was compared among the dose-dependent PET images. RESULTS: Our analysis shows that sufficient subjective image quality and lesion conspicuity could be maintained down to 1/30th (0.12 MBq/kg) of the administered dose of 18F-FDG, where good image quality scores were given to 1/2- and 1/10- dose groups. The image noise was significantly more deranged than the overall quality and lesion conspicuity in 1/30- to 1/10-dose groups (all p < 0.05). With reduced doses, quantitative analysis of ROIs showed that SUVmax and SD in the liver increased gradually (p < 0.05), but SUVmax in the lesions and lesion-to-background ratio (LBR) showed no significant deviation down to 1/30-dose. One hundred percent of the 18F-FDG-avid micro-lesions identified in full-dose images were localized down to 1/15-dose images, while 97% of the lesion were localized in 1/30-dose images. CONCLUSION: The total-body PET/CT might significantly decrease the administered dose upon maintaining the image quality and diagnostic performance of micro-lesions in pediatric patients. Data suggests that using total-body PET/CT, optimal image quality could be achieved with an administered dose-reduction down to 1/10-dose (0.37 MBq/kg).

11.
Water Res ; 196: 117039, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33761397

RESUMO

Ozone (O3) has been widely used for the elimination of recalcitrant micropollutants in aqueous environments, due to its strong oxidation ability. However, the utilization efficiency of O3 is constrained by its low solubility and short half-life during the treatment process. Herein, an integrated approach, using nanobubble technology and micro-environmental chemistry within cyclodextrin inclusion cavities, was studied in order to enhance the reactivity of ozonisation. Compared with traditional macrobubble aeration with O3 in water, nanobubble aeration achieved 1.7 times higher solubility of O3, and increased the mass transfer coefficient 4.7 times. Moreover, the addition of hydroxypropyl-ß-cyclodextrin (HPßCD) further increased the stability of O3 through formation of an inclusion complex in its molecule-specific cavity. At a HPßCD:O3 molar ratio of 10:1, the lifespan of O3 reached 18 times longer than in a HPßCD-free O3 solution. Such approach accelerated the removal efficiency of the model micropollutant, 4-chlorophenol by 6.9 times, compared with conventional macrobubble ozonation. Examination of the HPßCD inclusion complex by UV-visible spectroscopy and Nuclear Magnetic Resonance analyses revealed that both O3 and 4-chlorophenol entered the HPßCD cavity, and Benesi-Hildebrand plots indicated a 1:1 stoichiometry of the host and guest compounds. Additionally, molecular docking simulations were conducted in order to confirm the formation of a ternary complex of HPßCD:4-chlorophenol:O3 and to determine the optimal inclusion mode. With these results, our study highlights the viability of the proposed integrated approach to enhance the ozonation of organic micropollutants.


Assuntos
Ciclodextrinas , Ozônio , Poluentes Químicos da Água , 2-Hidroxipropil-beta-Ciclodextrina , Simulação de Acoplamento Molecular , Solubilidade , Poluentes Químicos da Água/análise
12.
Brain Res Bull ; 171: 67-74, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33662495

RESUMO

Given the sheer increased number of victims per year and the availability of only one effective treatment, acute ischemic stroke (AIS) remains to be one of the most under-treated serious diseases. Diabetes not only increases the incidence of ischemic stroke, but amplifies the ischemic damage, upon which if patients with diabetes suffer from stroke, he/she will confront increased risks of long-term functional deficits. The grim reality makes it a pressing need to intensify efforts at the basic science level to understand how diabetes impairs stroke recovery. This review retrospects the clinical and experimental studies in order to elucidate the detrimental effect of diabetes on cerebrovascular circulation including the major arteries/arterioles, collateral circulation, and neovascularization to shed light on further exploration of novel strategies for cerebral circulation protection before and after AIS in patients with diabetes.

13.
World Neurosurg ; 2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33647495

RESUMO

OBJECTIVE: Previous studies have investigated biomechanical characteristics of the lumbar spine after different types of lumbar interbody fusion surgery under static loadings. However, very few have dealt with the whole-body vibration (WBV) condition that is typically present in vehicles. The aim of this study was to compare the influence of posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) on dynamic responses of the fused lumbar spine to vertical WBV. METHODS: The PLIF and TLIF procedures with bilateral pedicle screw fixation at L4-L5 level were simulated by modifying a previously validated intact lumbar L1-S1 finite element model. The PLIF and TLIF models were subjected to a sinusoidal vertical load with a compressive follower preload, and computed for transient dynamic analysis. The obtained dynamic responses for the models at the fused and adjacent levels were collected and compared. RESULTS: The results showed that the contact force between endplate and cage was higher in the PLIF model than in the TLIF model, indicating that PLIF allowed for higher compressive load across the anterior structure. At fused L4-L5 level, the TLIF led to a higher stress in the endplate and posterior BPSF system than the PLIF. At adjacent L3-L4 level and L5-S1 level, the computed dynamic responses, in terms of stress and deformation, for the PLIF and TLIF models showed very few differences. CONCLUSIONS: This study may be helpful to quantify dynamic mechanical properties of the fused lumbar spine, and better understand biomechanical differences between the PLIF and TLIF procedures during vibration.

14.
J Safety Res ; 76: 101-117, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653541

RESUMO

INTRODUCTION: Bicyclists are more vulnerable compared to other road users. Therefore, it is critical to investigate the contributing factors to bicyclist injury severity to help provide better biking environment and improve biking safety. According to the data provided by National Highway Traffic Safety Administration (NHTSA), a total of 8,028 bicyclists were killed in bicycle-vehicle crashes from 2007 to 2017. The number of fatal bicyclists had increased rapidly by approximately 11.70% during the past 10 years (NHTSA, 2019). METHODS: This paper conducts a latent class clustering analysis based on the police reported bicycle-vehicle crash data collected from 2007 to 2014 in North Carolina to identify the heterogeneity inherent in the crash data. First, the most appropriate number of clusters is determined in which each cluster has been characterized by the distribution of the featured variables. Then, partial proportional odds models are developed for each cluster to further analyze the impacts on bicyclist injury severity for specific crash patterns. RESULTS: Marginal effects are calculated and used to evaluate and interpret the effect of each significant explanatory variable. The model results reveal that variables could have different influence on the bicyclist injury severity between clusters, and that some variables only have significant impacts on particular clusters. CONCLUSIONS: The results clearly indicate that it is essential to conduct latent class clustering analysis to investigate the impact of explanatory variables on bicyclist injury severity considering unobserved or latent features. In addition, the latent class clustering is found to be able to provide more accurate and insightful information on the bicyclist injury severity analysis. Practical Applications: In order to improve biking safety, regulations need to be established to prevent drinking and lights need to be provided since alcohol and lighting condition are significant factors in severe injuries according to the modeling results.

15.
J Safety Res ; 76: 184-196, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653550

RESUMO

INTRODUCTION: With the increasing trend of pedestrian deaths among all traffic fatalities in the past decade, there is an urgent need for identifying and investigating hotspots of pedestrian-vehicle crashes with an upward trend. METHOD: To identify pedestrian-vehicle crash locations with aggregated spatial pattern and upward temporal pattern (i.e., hotspots with an upward trend), this paper first uses the average nearest neighbor and the spatial autocorrelation tests to determine the grid distance and the neighborhood distance for hotspots, respectively. Then, the spatiotemporal analyses with the Getis-Ord Gi* index and the Mann-Kendall trend test are utilized to identify the pedestrian-vehicle crash hotspots with an annual upward trend in North Carolina from 2007 to 2018. Considering the unobserved heterogeneity of the crash data, a latent class model with random parameters within class is proposed to identify specific contributing factors for each class and explore the heterogeneity within classes. Significant factors of the pedestrian, vehicle, crash type, locality, roadway, environment, time, and traffic control characteristics are detected and analyzed based on the marginal effects. RESULTS: The heterogeneous results between classes and the random parameter variables detected within classes further indicate the superiority of latent class random parameter model. Practical Applications: This paper provides a framework for researchers and engineers to identify crash hotspots considering spatiotemporal patterns and contribution factors to crashes considering unobserved heterogeneity. Also, the result provides specific guidance to developing countermeasures for mitigating pedestrian-injury at pedestrian-vehicle crash hotspots with an upward trend.

17.
Sci Rep ; 11(1): 3323, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33558535

RESUMO

Accurate, long-term, full-coverage carbon dioxide (CO2) data in units of prefecture-level cities are necessary for evaluations of CO2 emission reductions in China, which has become one of the world's largest carbon-emitting countries. This study develops a novel method to match satellite-based Defense Meteorological Satellite Program's Operational Landscan System (DMSP/OLS) and Suomi National Polar-orbiting Partnership's Visible Infrared Imaging Radiometer Suite (NPP/VIIRS) nighttime light data, and estimates the CO2 emissions of 334 prefecture-level cities in China from 1992 to 2017. Results indicated that the eastern and coastal regions had higher carbon emissions, but their carbon intensity decreased more rapidly than other regions. Compared to previous studies, we provide the most extensive and long-term CO2 dataset to date, and these data will be of great value for further socioeconomic research. Specifically, this dataset provides a foundational data source for China's future CO2 research and emission reduction strategies. Additionally, the methodology can be applied to other regions around the world.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33555403

RESUMO

INTRODUCTION: To analyze how K-line is related to change in sagittal cervical curvature and laminoplasty outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL). MATERIALS AND METHODS: The study retrospectively analyzed 81 patients with OPLL who had undergone posterior cervical single-door laminoplasty and arch plate fixation between June 2011 and June 2017. Fifty-five were K-line positive (K[+]) and 26 were K-line negative (K[-]). Clinical and radiological results were compared between the groups. Patients were followed up for at least 2 years. RESULTS: Before the operation, Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS) score, neck disability index (NDI), and short-form-36 (SF-36) quality of life score did not differ significantly between the groups. Neurological function was improved in both groups after the procedure. At last follow-up, JOA score, VAS score, NDI, SF-36 score, and JOA score improvement rate differed significantly between the groups. Before the operation, at the 3-month and final follow-ups, C2-7 Cobb angle, T1 slope, and C2-7 SVA differed significantly between the groups. The changes were more marked in the K(-) group than in the K(+) group. The incidence of cervical kyphosis differed significantly between the groups (P < 0.05), as well as between patients with lordosis < 7° and those with lordosis ≥ 7°. CONCLUSIONS: K-line negativity and lordosis < 7° may predict kyphosis after laminoplasty in patients with OPLL. The cervical curvature in patients with OPLL tends towards kyphosis and anteversion after laminoplasty, which contributes to the reduced clinical effect of the procedure.

19.
Cell Host Microbe ; 29(3): 489-502.e8, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33548198

RESUMO

The SARS-CoV-2 virus, the causative agent of COVID-19, is undergoing constant mutation. Here, we utilized an integrative approach combining epidemiology, virus genome sequencing, clinical phenotyping, and experimental validation to locate mutations of clinical importance. We identified 35 recurrent variants, some of which are associated with clinical phenotypes related to severity. One variant, containing a deletion in the Nsp1-coding region (Δ500-532), was found in more than 20% of our sequenced samples and associates with higher RT-PCR cycle thresholds and lower serum IFN-ß levels of infected patients. Deletion variants in this locus were found in 37 countries worldwide, and viruses isolated from clinical samples or engineered by reverse genetics with related deletions in Nsp1 also induce lower IFN-ß responses in infected Calu-3 cells. Taken together, our virologic surveillance characterizes recurrent genetic diversity and identified mutations in Nsp1 of biological and clinical importance, which collectively may aid molecular diagnostics and drug design.


Assuntos
/imunologia , Interferon Tipo I/imunologia , /imunologia , Proteínas não Estruturais Virais/genética , Células A549 , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Sequência de Bases , Linhagem Celular , Criança , Pré-Escolar , Chlorocebus aethiops , Feminino , Deleção de Genes , Genômica , Células HEK293 , Humanos , Lactente , Interferon Tipo I/sangue , Interferon beta/sangue , Interferon beta/metabolismo , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Genética Reversa , Células Vero , Proteínas não Estruturais Virais/imunologia , Adulto Jovem
20.
Environ Pollut ; 275: 116626, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33609858

RESUMO

This study characterizes the impacts of transported peat-forest (PF) burning smoke on an urban environment and evaluates associated source burning conditions based on carbon properties of PM2.5 at the receptor site. We developed and validated a three-step classification that enables systematic and more rapid identification of PF smoke impacts on a tropical urban environment with diverse emissions and complex atmospheric processes. This approach was used to characterize over 300 daily PM2.5 data collected during 2011-2013, 2015 and 2019 in Singapore. A levoglucosan concentration of ≥0.1 µg/m3 criterion indicates dominant impacts of transported PF smoke on urban fine aerosols. This approach can be used in other ambient environments for practical and location-dependent applications. Organic carbon (OC) concentrations (as OC indicator) can be an alternate to levoglucosan for assessing smoke impacts on urban environments. Applying the OC concentration indicator identifies smoke impacts on ∼80% of daily samples in 2019 and shows an accuracy of 51-86% for hourly evaluation. Following the systematic identification of urban PM2.5 predominantly affected by PF smoke in 2011-2013, 2015 and 2019, we assessed the concentration ratio of char-EC/soot-EC as an indicator of smoldering- or flaming-dominated burning emissions. When under the influence of transported PF smoke, the mean concentration ratio of char-EC to soot-EC in urban PM2.5 decreased by >70% from 8.2 in 2011 to 2.3 in 2015 but increased to 3.8 in 2019 (p < 0.05). The reversed trend with a 65% increase from 2015 to 2019 shows stronger smoldering relative to flaming, indicating a higher level of soil moisture at smoke origins, possibly associated with rewetting and revegetating peatlands since 2016.


Assuntos
Poluentes Atmosféricos , Fumaça , Aerossóis/análise , Poluentes Atmosféricos/análise , Biomassa , Carbono/análise , Monitoramento Ambiental , Florestas , Material Particulado/análise , Estações do Ano , Singapura , Fumaça/análise , Solo
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