Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 237
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Int J Food Microbiol ; 317: 108492, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-31896043

RESUMO

Human noroviruses (HuNoVs) are the primary non-bacterial pathogens causing acute gastroenteritis worldwide. Attachment and invasion of HuNoVs are thought to involve histo-blood group antigens (HBGAs). Romaine lettuce, which is usually consumed raw, is a common food-related vehicle for HuNoVs transmission. This study investigated the possibility that bacteria resident on the surface of lettuce leaves contribute to norovirus adherence to this food. To test this hypothesis, bacteria were isolated from romaine lettuce and screened to evaluate whether they produced any polysaccharides with structures resembling HBGAs. Twenty-seven bacterial isolates were screened and 18, belonging to 13 different genera, were found to produce HBGAs-like polysaccharides that were recognized by monoclonal antibodies specific to type A, B, H and Lewis a, b, x and y. One bacterial isolate, belonging to the genus Pseudomonas was further investigated because it produced polysaccharides with the widest range of HBGA types, including type B, H and Lewis a, b and x. The Pseudomonas HBGAs-like polysaccharides were found to be extracellular and their production was enhanced when the bacteria were cultured in oligotrophic medium. HuNoVs capture assays revealed that GI.1, GI.8, and GII.2, GII.3, GII.4, GII.6, GII.12, GII.17 genotypes can be bind to Pseudomonas HBGAs-like polysaccharides. The direct evidence of bacterial production HBGAs-like polysaccharides demonstrates one possible mechanism driving accumulation of HuNoVs on lettuce.

2.
J Comp Eff Res ; 9(1): 35-44, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31777265

RESUMO

Aim: To compare the lateral and medial approaches of total knee arthroplasty (TKA) in the valgus knee. Materials & methods: An electronic search from the PubMed, Embase, Web of Science and Cochrane library was performed according to 'TKA', 'valgus', 'knee' and 'approach'. Subsequently, manual search was conducted from the reference lists in the identified studies. Results: Four randomized controlled trials and five cohorts were included. Better knee society score and function was noticed in patients after lateral approach. Similar postoperative valgus deformity, operative time, blood loss, Western Ontario and McMaster Universities Osteoarthritis Index, range of motion, pain and total complications in both groups. Conclusion: Compared with the medial approach for TKA in valgus knee, current data shows superior results after TKA by the lateral approach.

3.
Ann Transl Med ; 7(20): 549, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31807531

RESUMO

Background: To introduce a modified pleurodesis as an effective treatment for refractory chylothorax and to develop a novel insight for its mechanism. Methods: Patients who underwent thoracic surgery at West China Hospital or its affiliated hospitals between 2010 and 2015 and who subsequently experienced chylothorax that was not resolved by conventional treatment, received daily pleurodesis involving 100 mL 50% glucose and 20 mL 1% lidocaine. The chest tube was clamped after 7 days of pleurodesis, regardless of drainage amount. If no remarkable pulmonary atelectasis was detected within 2 days, the chest tube was removed. All patients were followed up with for at least 3 months after discharge from our hospital. Results: Among the 34 patients, 10 did not experience an increase in the pleural fluid after the chest tube was clamped. Minor effusion increase occurred in 21 patients, while encapsulated effusion occurred in 3. In 23 patients among the latter 24 patients, pleural fluid was gradually absorbed and disappeared spontaneously. One patient suffered chylothorax recurrence after discharge but successfully recovered after the second round of modified pleurodesis. Several patients suffered from electrolyte imbalance, weakness, and dyspnea; all were cured by plasma infusion and other symptomatic treatments. Conclusions: Being safe and effective for patients with postoperative refractory chylothorax, our modified pleurodesis enhanced the process of chemical pleurodesis and could remove the chest tube right after the extensive adhesion formed instead requiring a wait for drainage decrease. This method can thus shorten the period of hospitalization and reduce fluid loss compared with traditional pleurodesis.

4.
J Biophotonics ; : e201900242, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804752

RESUMO

Development of label-free methods for accurate classification of cells with high throughput can yield powerful tools for biological research and clinical applications. We have developed a deep neural network of DINet for extracting features from cross-polarized diffraction image (p-DI) pairs on multiple pixel scales to accurately classify cells in five types. A total of 6185 cells were measured by a polarization diffraction imaging flow cytometry (p-DIFC) method followed by cell classification with DINet on p-DI data. The averaged value and SD of classification accuracy were found to be 98.9% ± 1.00% on test data sets for 5-fold training and test. The invariance of DINet to image translation, rotation, and blurring has been verified with an expanded p-DI data set. To study feature-based classification by DINet, two sets of correctly and incorrectly classified cells were selected and compared for each of two prostate cell types. It has been found that the signature features of large dissimilarities between p-DI data of correctly and incorrectly classified cell sets increase markedly from convolutional layers 1 and 2 to layers 3 and 4. These results clearly demonstrate the importance of high-order correlations extracted at the deep layers for accurate cell classification.

5.
Huan Jing Ke Xue ; 40(9): 4160-4168, 2019 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854881

RESUMO

Ca2+ is an important microbial growth factor that can affect the activity, flocculation, and sedimentation of activated sludge. In order to study the roles of Ca2+ in the activated sludge system, the activity changes of ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) were analyzed using the specific oxygen uptake rates (SOURAOB and SOURNOB). The changes in composition and structure of extracellular polymeric substances (EPS) were analyzed using Fourier transform infrared spectroscopy (FTIR) and three-dimensional excitation emission fluorescence spectroscopy (3D-EEM). The effects of Ca2+on the nitrification activity and microbial metabolites were investigated. The results showed that when the Ca2+concentration increased from 0.45 mmol·L-1 to 3 mmol·L-1, SOURAOB and SOURNOB increased from 6.3 mg·(g·h)-1 to 10.4 mg·(g·h)-1 and from 2.3 mg·(g·h)-1 to 3.7 mg·(g·h)-1, respectively. The EPS concentrations increased from 68 mg·g-1 to 93 mg·g-1, and the flocculation ability (FA) of the sludge was improved. When the Ca2+ concentration was higher than 3 mmol·L-1, SOURAOB and SOURNOBboth decreased. The FA was maintained at about 30%, and the particle size of the sludge continued to increase. Based on FTIR analysis, the main components of EPS were always amino, amide Ⅰ, and carboxyl with an increase in Ca2+ concentration. Based on EEM analysis, the composition of loosely-bound (LB)-EPS did not change, and humic acid substances appeared in the tightly-bound (TB)-EPS at low nitrification rates. Low concentrations of Ca2+ promoted nitrification activity and flocculation of the sludge. However, high concentrations of Ca2+ led to a decline in the sludge nitrification activity.

6.
Appl Opt ; 58(34): 9443-9454, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31873536

RESUMO

In this paper, we investigate the propagation of partially coherent flat-topped (PCFT) beams through atmospheric turbulence along a slant path. Using wave optics simulation (WOS), we calculated the on-axis intensity of PCFT beams in both vacuum and turbulence links, finding that PCFT beams will self-focus during propagation and that the beam coherence length has a significant impact on this focusing phenomenon. The effects of the zenith angle and the source coherence length on the scintillation index and mean signal-to-noise ratio (SNR) are analyzed. Furthermore, taking into consideration the limitation of available devices, we examined the impacts of source coherence time and detector integration time on the performance of PCFT beams in slant links. WOS results indicate as much as an extra 2 dB SNR gain from PCFT beams in short links in comparison with Gaussian Schell-model beams.

7.
Int. j. morphol ; 37(4): 1245-1251, Dec. 2019. tab, graf
Artigo em Inglês | LILACS-Express | ID: biblio-1040119

RESUMO

SUMMARY: The aim of this study was to evaluate the effect of soft tissue thickness of upper lip on lip retraction in orthodonticaltreated females and identify the ratio of maxillary incisor retraction to upper lip retraction. Pre- and post-treatment lateral cephalograms of 100 adults were examined to measure the lip thickness in upper lip and establish the classification standard. All subjects were treated with 4 first premolar extractions followed by upper central incisors retraction. Pre- and post-treatment lateral cephalograms of 19 patients were reviewed to determine the changes of the upper lip and incisor positions through landmarks displacement. An independent-samples t test and one-way analysis of variance were performed. The correlations between maxillary incisor retraction and upper lip retraction were explored by the Pearson correlation method. P-values<0.05 were considered statistically significant. The lip thickness of adult male patients was greater than that of adult female patients. The average ratio of maxillary incisor retraction to upper lip repositioning was 1.6:1,1.9:1 and 2.2:1 in the thin lips group, normal lips group and thick lips group, respectively. Gender differences exist in the thickness of upper lip. Horizontal changes of the maxillary incisor showed a significant correlation to horizontal changes of the upper lip (P<0.001).There were negative correlations between the thickness of upper lip and the ratio between change in maxillary incisor protrusion and change in upper lip protrusion.


RESUMEN: El objetivo de este estudio fue evaluar el efecto del grosor de los tejidos blandos del labio superior, sobre la retracción del labio en mujeres tratadas con ortodoncia e identificar la proporción de retracción del diente incisivo maxilar con respecto a la retracción del labio superior. Se examinaron cefalogramas laterales, previos y posteriores al tratamiento de 100 adultos, para medir el grosor del labio superior y establecer un estándar de clasificación. Todos los sujetos fueron tratados con 4 extracciones de los primeros premolares seguidas de retracción de los incisivos centrales superiores. Se revisaron los cefalogramas laterales, previos y posteriores al tratamiento de 19 pacientes, para determinar los cambios del labio superior y las posiciones de los incisivos a través del desplazamiento de los puntos de referencia. Se realizó una prueba t de muestras independientes y un análisis de varianza de una vía. Las correlaciones entre la retracción del incisivo maxilar y la retracción del labio superior se exploraron mediante el método de correlación de Pearson. Los valores de p<0,05 fueron considerados estadísticamente significativos. El grosor de los labios de los pacientes adultos masculinos fue mayor que el de las pacientes adultas. La relación promedio de la retracción del incisivo maxilar al reposicionamiento del labio superior fue de 1,6:1,1; 9:1 y 2,2:1 en el grupo de labios delgados, grupo de labios normales y grupo de labios gruesos, respectivamente. Existen diferencias de sexo en el grosor del labio superior. Los cambios horizontales del incisivo maxilar mostraron una correlación significativa con los cambios horizontales del labio superior (P<0,001). Hubo correlaciones negativas entre el grosor del labio superior y la relación entre el cambio en la protuberancia del incisivo maxilar y el cambio en la protrusión del labio superior.

8.
J Agric Food Chem ; 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31755264

RESUMO

Human noroviruses (HuNoVs) are among the main pathogens causing acute nonbacterial gastroenteritis. Histo-blood group antigens (HBGAs) are widely accepted receptors for HuNoV specific binding. HBGA-like substances in produce are also considered as the critical ligands for capture of HuNoVs. However, the composition of viral ligands from food substrates remains unknown. In this study, an oligosaccharide (H2N2F2) was captured and isolated from romaine lettuce extract by a bacterial surface display system. Using electrospray ionization mass spectrometry and tandem mass spectrometry, it was shown that H2N2F2 was most likely to be a chimera of type A, H, and Lewis a HBGAs. The composition was consistent with our ELISA results using a panel of monoclonal antibodies against HBGAs. Our results revealed a possible interaction mechanism between HuNoVs and romaine lettuce. Better understanding of the interaction of HuNoVs with easily contaminated produce will ultimately aid in the control of and reduction in disease outbreaks.

9.
Fitoterapia ; 139: 104389, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31669963

RESUMO

A new heterodimer, rynchopeterine F (1), a new natural product, rynchopeterine G (2), and eleven known phenolics were isolated from Blap rynchopetera Fairmaire, a kind of medicinal insect utilized by the Yi and Bai Nationality in Yunnan Province of China. Their structures were established on the basis of extensive spectroscopic analyses (1D and 2D NMR, HR-MS) along with calculated electronic circular dichroism method. Rynchopeterine F was a unusual heterodimer of a 3,4-dihudroxy phenylethanol unit fused to a 3,4-dihudroxy phenylacetyl group through two ester bonds with lactic acid, and rynchopeterine G was a 3,4-dihudroxy phenylethanyl monoester succinate. Attributed to the adjacent dihydroxyl grops, compounds 1 and 2 exhibited significant anti-radical activity with an IC50 value of 3.52 and 7.83 µg/mL for DPPH radical-scavenging, similar with that of the positive controls, vitamin C, 6.92 µg/mL and rutin, 8.28 µg/mL.


Assuntos
Besouros/química , Depuradores de Radicais Livres/farmacologia , Fenóis/farmacologia , Animais , China , Depuradores de Radicais Livres/isolamento & purificação , Ácido Láctico/química , Estrutura Molecular , Fenóis/isolamento & purificação , Álcool Feniletílico/química
10.
Diagn Pathol ; 14(1): 114, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31639000

RESUMO

BACKGROUND: Recent studies have shown that T cell-mediated cellular immune mechanisms play important roles in the progression of hepatitis B to liver cirrhosis, but the underlying mechanisms remain unclear. This present study was aimed to determine the relationship between Treg/Th17 and hepatitis B-associated liver cirrhosis. METHODS: The Treg and Th17 cell frequencies in the peripheral blood of all participants, including 93 patients with hepatitis B-associated liver cirrhosis and 40 healthy subjects, were measured by flow cytometer. Cox regression model and receiver operating characteristic(ROC) curves were applied to investigate the prognostic significance of Treg/Th17 ratio in decompensated liver cirrhosis. RESULTS: We observed the Treg/Th17 imbalance was present in patients with hepatitis B-associated liver cirrhosis, with reduced Treg cells in their peripheral blood, increased Th17 cells and decreased Treg/Th17 ratio. Treg and Th17 cells were negatively correlated. Treg/Th17 imbalance was closely related to the clinical stage of hepatitis B-associated liver cirrhosis. The Virus load, Treg frequencies and the Treg/Th17 ratio were independent factors predicting decompensated liver cirrhosis from a Cox regression model. The ROC analysis showed that the Treg/Th17 ratio was the best marker for predicting decompensated liver cirrhosis. CONCLUSIONS: Treg/Th17 imbalance is involved in the pathogenesis of hepatitis B-associated liver cirrhosis and the Treg/Th17 ratio can be used as a potential marker for predicting decompensated liver cirrhosis.

11.
Adv Mater ; 31(50): e1902181, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31496008

RESUMO

Methanol conversion to olefins, as an important reaction in C1 chemistry, provides an alternative platform for producing basic chemicals from nonpetroleum resources such as natural gas and coal. Methanol-to-olefin (MTO) catalysis is one of the critical constraints for the process development, determining the reactor design, and the profitability of the process. After the construction and commissioning of the world's first MTO plant by Dalian Institute of Chemical Physics, based on high-efficiency catalyst and fluidization technology in 2010, more attention has been attracted for a deep understanding of the reaction mechanism and catalysis principle, which has led to the continuous development of catalysts and processes. Herein, the recent progress in MTO catalyst development is summarized, focusing on the advances in the optimization of SAPO-34 catalysts, together with the development efforts on catalysts with preferential ethylene or propylene selectivity.

12.
Adv Mater ; 31(37): e1903605, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31364796

RESUMO

Converting and storing intermittent solar energy into stable chemical fuels of high efficiency depend crucially on harvesting excess energy beyond the conventional ultraviolet light spectrum. The means of applying highly efficient solar-thermal conversion on practical electricity-driven water splitting could be a significant stride toward this goal, while some bottlenecks remain unresolved. Herein, photothermic electrocatalytic oxygen and hydrogen evolution reactions are proposed, which bestow a distinctive exothermic activation and electrochemical reactivity in a reconstructed electrolyzer system, and which are poised for efficient renewable energy production. Attributed to the synergistic in situ coupling of the N-doped carbon, metallic alloy and oxides, in view of their broadband light absorption, high electrochemical surface area, and efficient charge transfer attributes, the hybrid photothermal electrocatalytic electrode simultaneously satisfies efficient photon-to-heat conversion and augmented electrochemical catalytic activity. Finally, a system level design of an appropriate photothermally mediated electrolytic cell with close-proximity light-illumination window along with a low-thermal-emittance electrolyte separator that preserve an overall large localized thermal gradient and efficient mass transport is devised. Such a photothermally mediated electrocatalytic system presented here may open up new avenues for the development of solar-thermal energy utilization in other forms.

13.
J Mol Histol ; 50(5): 459-470, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302828

RESUMO

Temporomandibular joint osteoarthritis (TMJOA) is a complex inflammatory condition with multiple factors and degenerative processes co-occurring. However, its pathogenesis remains uncertain. The purpose of the study was to observe the expression of Indian hedgehog (Ihh) signal related molecules in TMJOA induced by bite-raising and to study the effect and mechanism of Ihh signaling. Our research indicated that Ihh signaling pathway can be activated in condylar cartilage induced by bite-raising. The histological analysis showed TMJOA-like structural changes of condylar cartilage in experiment groups. Ihh, Smoothened (Smo), and Gli zinc finger transcription factors-1 (Gli-1) were activated in the experimental groups, and the expression levels increased significantly over time, whereas the sham control groups showed no fluctuation. Additionally, the expression levels of matrix metalloproteinase-13 (MMP-13) and cysteinyl aspartate specific proteinase-3 (Caspase-3) in the experiment groups increased in a time-dependent manner compared with the matched sham control groups. In conclusion, our results indicated that the Ihh signaling pathway may activate the occurrence of TMJOA by mediating the hypertrophy of chondrocytes, which may be an important regulatory mechanism and potential therapeutic target in the repair of condylar cartilage.


Assuntos
Mordeduras e Picadas/metabolismo , Cartilagem/metabolismo , Condrócitos/patologia , Proteínas Hedgehog/metabolismo , Hipertrofia , Transdução de Sinais , Envelhecimento , Animais , Osso e Ossos , Osteoartrite/etiologia , Osteoartrite/patologia , Ratos , Transtornos da Articulação Temporomandibular/etiologia , Transtornos da Articulação Temporomandibular/patologia
14.
Sci Total Environ ; 693: 133556, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31362221

RESUMO

Understanding hydrological alteration of rivers and the potential driving factors are crucial for water resources management in the watershed. This study analyzed the daily runoff time series at six gauging stations during 1960-2016 in Wuding River basin, northwestern China. The Mann-Kendall test and Lee-Heghinian method were employed to detect the temporal trends and abrupt changes in annual streamflow. The flow duration curve (FDC) and the index of hydrologic alteration (IHA)/Range of Variability Approach (RVA) were applied to assess the daily streamflow and degree of hydrologic alteration (DHA). In addition, we analyzed the changes of index of hydrological connectivity (IC) and reservoirs/dams (RI) in 1990, 1995, 2000 and 2015 in the basin. The relationship between IC, RI and DHA were assessed to investigate the potential influences of land use changes and constructions of reservoirs/dams on hydrological alteration. The results indicated that annual streamflow at five stations showed significant downward trends (p < 0.01) from 1960 to 2016, and an abrupt changing point appeared in the beginning of 1970s in Wuding River basin. Exception is Qingyangcha station without significant changes, and Hanjiamao station with changing point in 1967. FDC analysis indicated that both high and low flow indices reduced greatly. The integral DHA were higher than 70% at all the stations in the Wuding River basin, suggesting great variation in the magnitude, duration, frequency, timing and rate of change of daily streamflow. Both IC value and RI had close relationship with DHA, implying that DHA was highly affected by land use changes and dams/reservoirs constructions, and was more sensitive to the land use change (p < 0.01). This study provides good insight to understand the effects of soil and water conservation measures on hydrological regime.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31238577

RESUMO

The landscape grain effect reflects the spatial heterogeneity of a landscape and it is used as a research core of landscape ecology. The landscape grain effect can be used to not only explore spatiotemporal variation characteristics of a landscape pattern, but also to disclose variation laws of ecological structures and functions of landscapes. In this study, the sensitivity of landscape pattern indexes to grain sizes 50-1000 m was studied based on landscape data in Yancheng Coastal Wetland acquired in 1991, 2000, 2008, and 2017. Response of the grain effect to landscape changes was analyzed and an optimal grain size for analysis in the study area was determined. Results indicated that: (1) among 27 indexes (12 in a class level and 15 in a landscape level), eight indexes were highly sensitive to grains, ten indexes presented moderate sensitivity, eight indexes presented low sensitivity, and one was unresponsive. It was shown that the area-margin index and the shape index were more sensitive to the different grain sizes. The aggregation index had some differences in the grain size change, and the diversity index had a low response degree to the grain size. (2) Landscape indexes showed six different responses to different grains, including slow reduced response, fast reduced and then slow reduced response, monotonically increased response, fluctuating reduced response, up-down responses, and stable response, which indicated that the landscape index was closely related to the spatial grain. (3) From 1991 to 2017, variation curves of the landscape grain size of different landscape types could be divided into four types: fluctuation rising type, fluctuation type, monotonous decreasing type, and monotonous rising type. Different grain size curves had different interpretations of landscape changes, but in general, Yancheng Coastal Wetland's landscape tended to be fragmented and complicated, internal connectivity was weakened, and dominant landscape area was reduced. Natural wetlands were more sensitive to grain size effects than artificial wetlands. (4) The landscape index at the 50 m grain size had a strong response to different grain size changes, and the loss of landscape information was the smallest. Therefore, it was determined that the optimal landscape grain size in the study area was 50 m.


Assuntos
Fenômenos Ecológicos e Ambientais , Áreas Alagadas , China
16.
J Med Primatol ; 48(6): 320-328, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31148186

RESUMO

BACKGROUND: The relatively tiny spinal cord of non-human primate (NHP) causes increased challenge in diffusion tensor imaging (DTI) post-processing. This study aimed to establish a reliable correction strategy applied to clinical DTI images of NHP. METHODS: Six normal and partial spinal cord injury (SCI) rhesus monkeys underwent 3T MR scanning. A correction strategy combining multiple iterations and non-rigid deformation was used for DTI image post-processing. Quantitative evaluations were then conducted to investigate effects of distortion correction. RESULTS: After correction, longitudinal geometric distortion, global distortion, and residual distance errors were all significantly decreased (P < 0.05). Fractional anisotropy at the injured site was remarkably lower than that at the contralateral site (P = 0.0488) and was substantially lower than those at the adjacent superior (P = 0.0157) and inferior (P = 0.0128) areas at the same side. CONCLUSIONS: Our image correction strategy can improve the quality of the DTI images of NHP thoracic cords, contributing to the development of SCI preclinical research.

17.
Neural Netw ; 118: 65-80, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31254769

RESUMO

We consider learning from comparison labels generated as follows: given two samples in a dataset, a labeler produces a label indicating their relative order. Such comparison labels scale quadratically with the dataset size; most importantly, in practice, they often exhibit lower variance compared to class labels. We propose a new neural network architecture based on siamese networks to incorporate both class and comparison labels in the same training pipeline, using Bradley-Terry and Thurstone loss functions. Our architecture leads to a significant improvement in predicting both class and comparison labels, increasing classification AUC by as much as 35% and comparison AUC by as much as 6% on several real-life datasets. We further show that, by incorporating comparisons, training from few samples becomes possible: a deep neural network of 5.9 million parameters trained on 80 images attains a 0.92 AUC when incorporating comparisons.


Assuntos
Bases de Dados Factuais/classificação
18.
Exp Anim ; 68(3): 341-349, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30930341

RESUMO

Walking is characterized by repetitive limb movements associated with highly structured patterns of muscle activity. The causal relationships between the muscle activities and hindlimb segments of walking are difficult to decipher. This study investigated these particular relationships and clarified whether they are correlated with speed to further understand the neuromuscular control pattern. Four adult female rhesus monkeys (Macaca mulatta) were selected to record gait parameters while walking on a bipedal treadmill at speeds of 0.2, 0.8, 1.4, and 2.0 km/h. We recorded 3 ipsilateral hindlimb muscles by surface recording. In this study, we calculated the correlations between electromyography (EMG) and kinematic parameters (24 EMG*17 kinematic parameters). Of the 408 calculated coefficients, 71.6% showed significant linear correlations. Significant linear correlations were found between muscle activity, such as burst amplitudes and the integral of muscle activity, and the corresponding kinematic parameters of each joint. Most of these relationships were speed independent (91.7% of all variables). Through correlation analysis, this study demonstrated a causal association between kinematic and EMG patterns of rhesus monkey locomotion. Individuals have particular musculoskeletal control patterns, and most of the relationships between hindlimb segments and muscles are speed independent. The current findings may enhance our understanding of neuromusculoskeletal control strategies.


Assuntos
Macaca mulatta/fisiologia , Músculo Esquelético/fisiologia , Caminhada/fisiologia , Animais , Fenômenos Biomecânicos , Eletromiografia , Feminino
19.
J Comp Eff Res ; 8(7): 511-521, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30907632

RESUMO

Aim: The objective of this study was to systematically compare the safety and efficacy of porous tantalum metal (TM) implants and autograft in single-level anterior cervical discectomy and fusion. Methods: Potential academic articles were acquired from the Cochrane Library, Medline, PubMed, Embase, Science Direct and other databases. The time range used was from the inception of the electronic databases to March 2018. Gray studies were identified from the references of included literature reports. STATA version 11.0 (Stata Corporation, TX, USA) was used to analyze the pooled data. Results: Four randomized, controlled trials (RCTs) were identified according to the retrieval process. There were significant differences in operation time (mean difference [MD]: -28.846, 95% confidence interval [CI: -47.087, -10.604], p = 0.002) and satisfaction rate (odds ratio [OR]: 2.196, 95% CI: [1.061-4. 546]; p = 0.034). However, no significant difference was detected in blood loss (MD: -73.606, 95% CI: [-217.720, 70.509], p = 0.317), hospital stay (MD: -0.512, 95% CI [-1.082, 0.058]; p = 0.079), fusion rate (OR: 0.497, 95% CI [0.079, 3.115]; p = 0.455), visual analog scale (MD: -0.310, 95% CI [-0.433, -0.186]; p < 0.001) or complication rate (risk difference [RD]: -0.140, 95% CI: [-0.378, 0.099]; p = 0.251). Conclusion: Porous TM implants are equally as effective and safe as autograft in anterior cervical discectomy and fusion processes. In addition, porous TM implants could reduce operation time and improve clinical satisfaction significantly.

20.
Int J Food Microbiol ; 298: 11-19, 2019 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-30889474

RESUMO

Norovirus is a very contagious virus that causes acute gastroenteritis. Contaminated produce is a main vehicle for dissemination of human noroviruses (HuNoVs). As HuNoVs could bind to bacteria effectively, it is highly possible that produce could be contaminated by bacteria-HuNoVs complex. In this study, we used a bacterial-surface-display system to express genogroup I (GI) or genogroup II (GII) HuNoV capsid protein (P protein) on the surface of bacteria. The bacteria-P protein complex (BPC) was used to characterize the conditions for binding to Romaine lettuce extract and removal of the bound BPCs. We demonstrated both GI and GII BPCs could bind to extract from leaf (LE) and vein (VE) effectively. Carbohydrates in LE and VE were involved in GI BPCs binding, and both carbohydrates and proteins were involved in GII BPCs binding. Saliva from both type A and O secretors could completely block binding of both BPCs to LE and VE. Saliva from type B secretors only partially blocked binding of GII but not GI BPCs to LE and VE. However, LE- and VE-bound BPCs could not be reversely removed by washing solution containing free HBGAs from saliva. The binding of GI BPCs to LE and VE was enhanced when pH was below pI (6.1) of GI and reduced when pH was above pI of GI (p < 0.05). The optimal binding for GII BPCs to LE and VE occurred at pI (6.4) of GII. All LE- or VE-bound BPCs could be reversely removed by washing with low (3.0-5.0) or high (9.0-10.0) pH buffer. The effect of ionic strength (NaCl and MgCl2, from zero to 100 g/L) on binding of BPCs to LE and VE was tested. The optimal ionic strength for binding of BPCs to LE and VE was 10.0 g/L (GI) and 5.0 g/L (GII) for NaCl, and 5.0 g/L for MgCl2. LE- and VE-bound BPCs could be reversely removed by washing with high ionic solutions. All LE- or VE- bound BPCs could be released when washed with NaCl concentrations of above 75.0 g/L (GI) and 25.0 g/L (GII), or with MgCl2 concentrations of above 75.0 g/L (GI) and 50.0 g/L (GII). Binding of BPCs to LE and VE was inhibited in the presence of Tween-80 (nonionic surfactant) as low as 0.05% (v/v). All LE- and VE-bound BPCs could be reversed by Tween-80 concentrations over 0.1% (v/v). The study provided important parameters for BPCs binding to and removal from lettuce extract.


Assuntos
Proteínas do Capsídeo/metabolismo , Microbiologia de Alimentos , Alface/virologia , Norovirus/metabolismo , Bactérias/virologia , Carboidratos/química , Ligação Proteica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA