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1.
Sci Data ; 11(1): 233, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38395911

RESUMO

Yunling cattle is a new breed of beef cattle bred in Yunnan Province, China. It is bred by crossing the Brahman, the Murray Grey and the Yunnan Yellow cattle. Yunling cattle can adapt to the tropical and subtropical climate environment, and has good reproductive ability and growth speed under high temperature and high humidity conditions, it also has strong resistance to internal and external parasites and with good beef performance. In this study, we generated a high-quality chromosome-level genome assembly of a male Yunling cattle using a combination of short reads sequencing, PacBio HiFi sequencing and Hi-C scaffolding technologies. The genome assembly(3.09 Gb) is anchored to 31 chromosomes(29 autosomes plus one X and Y), with a contig N50 of 35.97 Mb and a scaffold N50 of 112.01 Mb. It contains 1.62 Gb of repetitive sequences and 20,660 protein-coding genes. This first construction of the Yunling cattle genome provides a valuable genetic resource that will facilitate further study of the genetic diversity of bovine species and accelerate Yunling cattle breeding efforts.


Assuntos
Bovinos , Cromossomos , Genoma , Animais , Bovinos/genética , Masculino , China , Anotação de Sequência Molecular , Filogenia , Sequências Repetitivas de Ácido Nucleico
2.
Genes (Basel) ; 14(12)2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38136963

RESUMO

The Yunling cattle breed, a three-breed crossbreed, which comprises 50% Brahman cattle, 25% Murray Grey cattle and 25% Yunnan Yellow cattle, has several advantageous traits, including rapid growth, superior meat quality, ability to improve tolerance in hot and humid climates, tick resistance and rough feed. It can be rightfully stated that Yunling cattle serve as vital genetic repositories of the local Yunnan cattle. Gaining insights into the genetic information of Yunling cattle plays a significant role in the formulation of sound breeding strategies for this breed, safeguarding genetic resources and mitigating the risks associated with inbreeding depression. In this study, we constructed the Yunling cattle standard reference genome and aligned the whole genomes of 129 Yunling cattle individuals to the constructed reference genome to estimate the current genetic status of Yunling cattle in Yunnan Province, China. The average alignment rate and the average percentage of properly paired are both 99.72%. The average nucleotide diversity in Yunling cattle is 0.000166, which indicates a lower level of diversity. Population structure analysis classified Yunling cattle into two subgroups. Inbreeding analysis revealed that inbreeding events did occur in the Yunling cattle, which may have contributed to the low genetic diversity observed. This study presents a comprehensive assessment of the genetic structure and diversity among the Yunling cattle and provides a theoretical foundation for the preservation and exploitation of these precious germplasm resources.


Assuntos
Variação Genética , Genoma , Humanos , Bovinos/genética , Animais , China , Genoma/genética , Análise de Sequência de DNA , Fenótipo , Variação Genética/genética
3.
Phytother Res ; 37(9): 3926-3938, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37291961

RESUMO

The random-pattern skin flap is a generally used technique to cover the soft tissue defect, while its application is often constrained by complications after the flap transplant. Necrosis of the flap remains a principal obstacle. The purpose of this study was to investigate the effect of Baicalin on skin flap survival and its mechanism. First of all, we discovered that administering Baicalin stimulated cell migration and boosted the formation of capillary tubes in human umbilical vein endothelial cells. Then, we detected that Baicalin reduced apoptosis-induced oxidative stress by using western blot and oxidative stress test kit. After that, we observed that Baicalin increased autophagy and utilized 3MA to block autophagy augmentation substantially reversing the effects of Baicalin therapy. Furthermore, we uncovered the underlying mechanisms of Baicalin-induced autophagy via AMPK-regulated TFEB nuclear transcription. Finally, our in vivo experiment findings showed that Baicalin reduces oxidative stress, inhibits apoptosis, promotes angiogenesis, and boosts the levels of autophagy. After autophagy was blocked, substantially reversing the effects of Baicalin therapy. Our study indicated that Baicalin-induced autophagy via AMPK regulated TFEB nuclear transcription and then promotes angiogenesis and against oxidative stress and apoptotic promotes skin flap survival. These findings highlight the therapeutic potential for the clinical application of Baicalin in the future.


Assuntos
Proteínas Quinases Ativadas por AMP , Flavonoides , Humanos , Células Endoteliais da Veia Umbilical Humana , Flavonoides/farmacologia , Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/farmacologia
4.
IEEE Trans Pattern Anal Mach Intell ; 45(1): 73-86, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34971528

RESUMO

Visual navigation and three-dimensional (3D) scene reconstruction are essential for robotics to interact with the surrounding environment. Large-scale scenarios and computational robustness are great challenges facing the research community to achieve this goal. This paper raises a pose-only imaging geometry representation and algorithms that might help solve these challenges. The pose-only representation, equivalent to the classical multiple-view geometry, is discovered to be linearly related to camera global translations, which allows for efficient and robust camera motion estimation. As a result, the spatial feature coordinates can be analytically reconstructed and do not require nonlinear optimization. Comprehensive experiments demonstrate that the computational efficiency of recovering the scene and associated camera poses is significantly improved by 2-4 orders of magnitude.

5.
Appl Opt ; 61(8): 2007-2018, 2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35297893

RESUMO

An increasing number of bio-inspired navigation approaches have been designed based on polarization cameras. However, digital cameras can sense a much narrower field of vision than the vision of insects or human beings. In this study, we propose an adaptive skylight polarized orientation method for high dynamic range (HDR) scenes. Initially, we built a model of the image acquisition pipeline that can recover HDR irradiance maps from polarization images. Subsequently, the orientation method was designed based on a combination of the irradiance maps and the least squares methods. Some preprocessing steps were utilized to eliminate occlusion interference. In addition, an autoexposure adjustment method was proposed using information entropy and heuristic segmentation. Finally, the experimental results show that the proposed method can improve the accuracy of bionic orientation and adaption to skylight with occlusions and interference in natural conditions.


Assuntos
Biônica , Diagnóstico por Imagem , Animais , Humanos , Insetos , Análise dos Mínimos Quadrados
7.
BMC Musculoskelet Disord ; 21(1): 536, 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32781995

RESUMO

BACKGROUND: Previous studies have confirmed the feasibility of the cortical bone trajectory (CBT) technique. However, there are few reports on spinous process violation and screw penetration during the screw insertion. The purpose of this study was to evaluate the incidence of spinous process violation and screw penetration through the pedicle during CBT screw insertion. METHODS: Computed tomography (CT) scans with normal lumbar structures were consecutively obtained and three-dimensional (3D) reconstructions of the lumbar spine were created. Bilateral CBT screw placement was simulated on each segment using a screw diameter of 4.5 mm, 5.0 mm, or 5.5 mm. Incidences of these complications were recorded and analyzed. RESULTS: A total of 90 patients were enrolled. Spinous process violation was observed in 68.3, 53.3, 25.5, 1.7, and 0% from L1 to L5, respectively, using 4.5 mm screws. A significant difference was found among the five segments but this was unconnected to gender or screw diameter. The incidence of screw penetration through the inner wall decreased from L1 to L4; in turn, L1 (16.7-35.5%), L2 (12.7-34.4%), L3 (2.8-23.8%) and L4 (1.1-6.7%). This trend was reversed in L5 (6.7-16.7%). Moreover, screw penetration through the outer wall was rare. The incidence of screw penetration varied with screw size as well as lumbar level, but not with gender. CONCLUSIONS: There are more difficulties of CBT screw fixation in upper lumbar spine. The low rate of screw penetration, using 4.5 mm screws, suggests the safety for CBT fixation in the lumbar spine. Larger screws (5.0 mm or 5.5 mm) are more recommended for use in the lower lumbar spine. Moreover, CBT fixation in L5 deserves greater attention because of the unique morphology of the pedicle.


Assuntos
Parafusos Pediculares , Fusão Vertebral , Osso e Ossos , Osso Cortical/diagnóstico por imagem , Osso Cortical/cirurgia , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Região Lombossacral , Parafusos Pediculares/efeitos adversos , Fusão Vertebral/efeitos adversos
8.
Neurochem Res ; 44(4): 763-775, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30603983

RESUMO

Traumatic spinal cord injury (SCI) is a devastating condition with few efficacious drugs. Sinomenine, a bioactive alkaloid extracted from medicinal herb, has been used as a treatment of rheumatoid diseases. This present study explored the therapeutic effects of sinomenine on locomotor dysfunction and neuropathology in SCI. Our findings revealed that sinomenine mitigated neurological deficits and enhanced neuronal preservation, paralleled with a reduction of apoptosis. Also, sinomenine significantly reduced inflammatory cytokines and oxidative stress factors. We further examined erythroid-2-related factor 2 (Nrf2) nuclear translocation, which mainly controls the coordinated expression of important antioxidant and detoxification genes. An increase in Nrf2 translocation from cytoplasm to nucleus and Nrf2-mediated transactivation was observed after sinomenine administration. Knocking down Nrf2 by siRNA could counteract sinomenine-mediated anti-oxidant stress and anti-inflammation following H2O2-stimulated and LPS-stimulated PC12 cells. Together, our findings indicated that sinomenine has the potential to be an effective therapeutic agent for SCI by inhibiting inflammation and oxidative stress via Nrf2 activation.


Assuntos
Morfinanos/uso terapêutico , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/metabolismo , Animais , Feminino , Peróxido de Hidrogênio/toxicidade , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Morfinanos/farmacologia , Fator 2 Relacionado a NF-E2/agonistas , Estresse Oxidativo/fisiologia , Células PC12 , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Vértebras Torácicas
9.
Mol Med Rep ; 18(6): 5427-5436, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30365119

RESUMO

Intervertebral disc degeneration (IDD) is a multifactorial disease with few efficacious clinical drugs, which has been demonstrated to be associated with nucleus pulposus (NP) cells apoptosis and degeneration of the extracellular matrix (ECM). Interleukin (IL)­1ß, a common proinflammatory cytokine, is considered to be one of key regulators in IDD development. Andrographolide (AG), extracted from Andrographis paniculata, has been suggested to possess marked anti­inflammatory properties. However, the effects of AG on IDD has not been well explored. The present study aimed to investigate the effects and the mechanisms of AG on IDD in human NP cells. NP cells were treated with IL­1ß in the absence or presence of AG to investigate the effects on cell viability, cellular apoptosis, production of ECM and matrix metalloproteinase (MMP)­3, MMP­9 and MMP­13, and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)­4 and ADAMTS­5. It was identified that IL­1ß­induced NP cellular apoptosis was significantly inhibited by AG treatment. Furthermore, AG mitigated the IL­1ß­induced degeneration of the ECM, which was paralleled by a decrease in MMPs and ADAMTS levels. In addition, AG exhibited marked inhibitory properties against the activation of Toll­like receptors (TLRs), Myeloid differentiation factor 88 (MyD88) and the nuclear translocation of Nuclear factor kappa­light­chain­enhancer of activated B cells (NF­κB). Taken together, these results demonstrated that AG treatment mitigated IL­1ß­induced NP cells degeneration through the TLR4/MyD88/NF­κB signaling pathway, and suggested that AG may be a potential agent for IDD prevention and therapy.


Assuntos
Diterpenos/farmacologia , Interleucina-1beta/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Núcleo Pulposo/citologia , Núcleo Pulposo/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Degeneração do Disco Intervertebral/etiologia , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/patologia , Metaloproteinases da Matriz/metabolismo
10.
Clin Spine Surg ; 31(6): E310-E316, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29864077

RESUMO

STUDY DESIGN: This was a longitudinal cohort study. OBJECTIVE: The main objective of this study was to investigate the outcomes of surgery with or without radiotherapy during treatment of patients with chondrosarcoma of the osseous spine. SUMMARY OF BACKGROUND DATA: Chondrosarcoma is a primary spinal malignant tumor; chemotherapy and radiotherapy (RT) are generally unsuccessful, and thus, the main treatment of choice is complete en bloc resection. However, even with complete resection, these patients still have a significant rate of recurrence, morbidity, and mortality. Although there have been reports that the addition of RT to surgery may lead to increased survival and better cancer control, the evidence of the efficacy of RT remains controversial. MATERIALS AND METHODS: Patients diagnosed with chondrosarcoma who are then treated by surgery alone or surgery+RT were identified and extracted from the SEER (Surveillance, Epidemiology, and End Results) database (1973-2013). Propensity score matched (PSM) analysis was performed to balance patient characteristics between surgery alone and surgery+RT groups. Patients with a different grade and stage were stratified and analyzed. RESULTS: A total of 778 patients with chondrosarcoma of the osseous spine treated by surgery alone or surgery+RT were extracted from the SEER database. Before PSM, the unadjusted Kaplan-Meier curve and bivariable Cox proportional hazard regression models showed that the surgery alone group had higher chondrosarcoma cancer-specific survival and overall survival than the surgery+RT group (both P<0.001), while the difference was attenuated after PSM. Stratified analysis found that RT was worse for low-grade chondrosarcoma patients and had a better trend for high-grade chondrosarcoma patients. CONCLUSIONS: The results of our present study suggest that low-grade chondrosarcoma of the osseous spine is resistant to RT, while high-grade chondrosarcoma patients had a better trend with RT. LEVEL OF EVIDENCE: Level III.


Assuntos
Condrossarcoma/radioterapia , Condrossarcoma/cirurgia , Neoplasias da Coluna Vertebral/radioterapia , Neoplasias da Coluna Vertebral/cirurgia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Terapia Combinada , Feminino , Humanos , Lactente , Estimativa de Kaplan-Meier , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Adulto Jovem
11.
World Neurosurg ; 116: e211-e216, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29729457

RESUMO

BACKGROUND: Anterior odontoid screw fixation (AOSF) has been suggested as the optimal treatment for type II and some shallow type III odontoid fractures. However, only the classical surgical trajectory is available; no newer entry points or trajectories have been reported. METHODS: We evaluated the anatomic feasibility of a new trajectory for AOSF using 3-dimensional (3D) screw insertion simulation software (Mimics). Computed tomography (CT) scans of patients (65 males and 59 females) with normal cervical structures were obtained consecutively, and the axes were reconstructed in 3 dimensions by Mimics software. Then simulated operations were performed using 2 new entry points below the superior articular process using bilateral screws of different diameters (group 1: 4 mm and 4 mm; group 2: 4 mm and 3.5 mm; group 3: 3.5 mm and 3.5 mm). The success rates and the required screw lengths were recorded and analyzed. RESULTS: The success rates were 79.03% for group 1, 95.16% for group 2, and 98.39% for group 3. The success rates for groups 2 and 3 did not differ significantly, and both were significantly better than the rate for group 1. The success rate was much higher in males than in females in group 1, but the success rate was similar in males and females in the other 2 groups. Screw lengths did not differ significantly among the 3 groups, but an effect of sex was apparent. CONCLUSIONS: Our modified trajectory is anatomically feasible for fixation of anterior odontoid fractures, but further anatomic experiments and clinical research are needed.


Assuntos
Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/métodos , Processo Odontoide/cirurgia , Software , Fraturas da Coluna Vertebral/cirurgia , Adulto , Idoso , Simulação por Computador , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
Food Funct ; 9(4): 2374-2385, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29589609

RESUMO

Wound therapy remains a clinical challenge due to the poor vascularization during the healing process and the high demand to achieve functional and aesthetically satisfactory scars. Newly-formed blood vessels are necessary for wound healing since they can deliver nutrients and oxygen to the wound area. In this study, the role of leonurine (LN), a traditional Chinese medicine isolated from Herba leonuri, in promoting angiogenesis and its function in wound healing have been investigated. The results of co-culture with human umbilical vein endothelial cells (HUVECs) demonstrated that LN treatment (5-20 µM) could promote the proliferation and migration and enhance the ability of in vitro angiogenesis through up-regulating the mTOR/ERK signaling pathway. Furthermore, a full-thickness cutaneous wound model was used to investigate the healing effect of LN in vivo. Intragastric administration of 20 mg per kg per day LN stimulated the regeneration of more blood vessels at the wound sites, which confirmed the in vitro results of promoting angiogenesis. Due to fast vascularization, the collagen matrix deposition and remodeling processes were also accelerated in LN treated wounds, resulting in efficient wound healing. In summary, LN promoted angiogenesis of endothelial cells in vitro by activating the mTOR/ERK pathway, and could efficiently enhance the angiogenesis and collagen deposition of the regenerated tissue, together with facilitating the wound healing process in vivo. This study provides evidence for LN-stimulated angiogenesis and tissue regeneration in skin wounds, especially in ischemic wounds.


Assuntos
Indutores da Angiogênese/administração & dosagem , Medicamentos de Ervas Chinesas/administração & dosagem , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Ácido Gálico/análogos & derivados , Regeneração/efeitos dos fármacos , Pele/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Ferimentos e Lesões/tratamento farmacológico , Animais , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/genética , Ácido Gálico/administração & dosagem , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Neovascularização Patológica , Ratos , Transdução de Sinais/efeitos dos fármacos , Pele/irrigação sanguínea , Pele/metabolismo , Pele/fisiopatologia , Serina-Treonina Quinases TOR/genética , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/genética , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/fisiopatologia
13.
World Neurosurg ; 109: e829-e834, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29107721

RESUMO

BACKGROUND: Patients with laminar fractures have a higher chance of experiencing severe trauma and neurologic deficit. In previous studies, laminar fractures were divided into different types based on the axial plane of computed tomographic scans. No report described the morphology of vertical laminar fractures in the coronal plane. Furthermore, the correlation between a specific type of laminar fracture and the extent of severity of thoracolumbar (TL) burst fractures has rarely been mentioned. METHODS: A retrospective evaluation of 341 patients with TL burst fractures with or without laminar fractures were divided into 6 groups based on the morphology observed across reconstructed coronal and axial computed tomographic planes. The Thoracolumbar Injury Classification and Severity Score (TLICS), Load Sharing Classification (LSC), and American Spinal Injury Association (ASIA) impairment scale were evaluated for each patient. Intergroup comparisons were also performed for all metrics. RESULTS: The TLICS, LSC, and ASIA impairment scale were determined for each laminar fracture group. Statistical differences were found in most intergroup comparisons across all metrics. Significantly higher injury scores were observed in the groups with a more severe coronal and axial laminar fracture, and the injury severity in the coronal scan played a more decisive role. CONCLUSIONS: The morphology of vertical laminar fractures as observed across multiple image planes was more complex and accurate than an analysis based solely on the axial plane. Different morphologies indicated differences in the severity of associated TL burst fractures. The laminar fracture in the coronal plane was associated with the severity of spinal injury.


Assuntos
Vértebras Lombares/diagnóstico por imagem , Fraturas da Coluna Vertebral/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Acidentes por Quedas , Acidentes de Trânsito , Adulto , Feminino , Humanos , Escala de Gravidade do Ferimento , Vértebras Lombares/lesões , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Vértebras Torácicas/lesões , Tomografia Computadorizada por Raios X
14.
Acta Pharmacol Sin ; 39(3): 393-404, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29219948

RESUMO

Wound therapy remains a clinical challenge due to the complexity of healing pathology and high demand of achieving functional and aesthetically satisfactory scars. Newly formed blood vessels are essential for tissue repair since they can support cells at the wound site with nutrition and oxygen. In this study, we investigated the effects of Asperosaponin VI (ASA VI) isolated from a traditional Chinese medicine, the root of Dipsacus asper Wall, in promoting angiogenesis, as well as its function in wound therapeutics. Treatment of human umbilical vein endothelial cells (HUVECs) with ASA VI (20-80 µg/mL) dose-dependently promoted the proliferation, migration and enhanced their angiogenic ability in vitro, which were associated with the up-regulated HIF-1α/VEGF signaling. Full-thickness cutaneous wound model rats were injected with ASA VI (20 mg·kg-1·d-1, iv) for 21 d. Administration of ASA VI significantly promoted the cutaneous wound healing, and more blood vessels were observed in the regenerated tissue. Due to rapid vascularization, the cellular proliferation status, granulation tissue formation, collagen matrix deposition and remodeling processes were all accelerated, resulting in efficient wound healing. In summary, ASA VI promotes angiogenesis of HUVECs in vitro via up-regulating the HIF-1α/VEGF pathway, and efficiently enhances the vascularization in regenerated tissue and facilitates wound healing in vivo. The results reveal that ASA VI is a potential therapeutic for vessel injury-related wounds.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Neovascularização Fisiológica/fisiologia , Saponinas/farmacologia , Fator A de Crescimento do Endotélio Vascular/fisiologia , Cicatrização/efeitos dos fármacos , Animais , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Ratos , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
15.
Spine (Phila Pa 1976) ; 43(11): 774-779, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28953708

RESUMO

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To reveal the risk factors for dural tears in thoracic and lumbar (TL) burst fractures associated with vertical laminar fractures through multivariate analysis. SUMMARY OF BACKGROUND DATA: Dural tears associated with laminar fractures in patients with TL burst fractures represents a special group requires distinct treatment with different surgical prognosis. It is still very difficult to predict dural tears in patients with vertical laminar fractures. The risk factors for dural tears have seldom been evaluated. METHODS: Medical records of 113 patients of TL burst fractures with vertical laminar fractures were reviewed. The data were subdivided into two groups consisting of patients with and without dural tears. Demographic information, preoperative clinical, and radiological characteristics were compared between the groups. Multivariate logistic regression models were employed to determine the independent risk factors for dural tears. RESULTS: The incidence of dural tear was 27.4% in this retrospective cohort. When compared with the dural intact group, the dural tear group had significantly worse preoperative neurological status, wider interpedicular distance, greater separation of laminar fractures, and larger encroachment of retropulsed fragment in the bony spinal canal. Multivariate stepwise logistic regression analysis showed that the ratio of interpedicular distance greater than 125% (odds ratio = 9.5; P < 0.001) and the ratio of encroachment of retropulsed fragment in the bony spinal canal of more than 50% (odds ratio = 61.2; P < 0.001) were independent risk factors for dural tears. CONCLUSION: Patients with wider interpedicular distance and larger encroachment of retropulsed fragment in the bony spinal canal were more likely to have dural tears in TL burst fractures with vertical laminar fractures. LEVEL OF EVIDENCE: 3.


Assuntos
Dura-Máter/lesões , Vértebras Lombares/lesões , Traumatismos da Medula Espinal/etiologia , Fraturas da Coluna Vertebral/complicações , Vértebras Torácicas/lesões , Adulto , Dura-Máter/diagnóstico por imagem , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Traumatismos da Medula Espinal/diagnóstico por imagem , Fraturas da Coluna Vertebral/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X
16.
Sensors (Basel) ; 17(11)2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29135927

RESUMO

Animals, such as Savannah sparrows and North American monarch butterflies, are able to obtain compass information from skylight polarization patterns to help them navigate effectively and robustly. Inspired by excellent navigation ability of animals, this paper proposes a novel image-based polarized light compass, which has the advantages of having a small size and being light weight. Firstly, the polarized light compass, which is composed of a Charge Coupled Device (CCD) camera, a pixelated polarizer array and a wide-angle lens, is introduced. Secondly, the measurement method of a skylight polarization pattern and the orientation method based on a single scattering Rayleigh model are presented. Thirdly, the error model of the sensor, mainly including the response error of CCD pixels and the installation error of the pixelated polarizer, is established. A calibration method based on iterative least squares estimation is proposed. In the outdoor environment, the skylight polarization pattern can be measured in real time by our sensor. The orientation accuracy of the sensor increases with the decrease of the solar elevation angle, and the standard deviation of orientation error is 0 . 15 ∘ at sunset. Results of outdoor experiments show that the proposed polarization navigation sensor can be used for outdoor autonomous navigation.


Assuntos
Calibragem , Animais , Análise dos Mínimos Quadrados , Orientação , Luz Solar
17.
IEEE Trans Pattern Anal Mach Intell ; 39(6): 1209-1222, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27333597

RESUMO

In this paper we deal with the camera pose estimation problem from a set of 2D/3D line correspondences, which is also known as PnL (Perspective-n-Line) problem. We carry out our study by comparing PnL with the well-studied PnP (Perspective-n-Point) problem, and our contributions are three-fold: (1) We provide a complete 3D configuration analysis for P3L, which includes the well-known P3P problem as well as several existing analyses as special cases. (2) By exploring the similarity between PnL and PnP, we propose a new subset-based PnL approach as well as a series of linear-formulation-based PnL approaches inspired by their PnP counterparts. (3) The proposed linear-formulation-based methods can be easily extended to deal with the line and point features simultaneously.

18.
Sensors (Basel) ; 15(6): 12816-33, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26039422

RESUMO

This paper presents a novel approach for estimating the ego-motion of a vehicle in dynamic and unknown environments using tightly-coupled inertial and visual sensors. To improve the accuracy and robustness, we exploit the combination of point and line features to aid navigation. The mathematical framework is based on trifocal geometry among image triplets, which is simple and unified for point and line features. For the fusion algorithm design, we employ the Extended Kalman Filter (EKF) for error state prediction and covariance propagation, and the Sigma Point Kalman Filter (SPKF) for robust measurement updating in the presence of high nonlinearities. The outdoor and indoor experiments show that the combination of point and line features improves the estimation accuracy and robustness compared to the algorithm using point features alone.

19.
Sensors (Basel) ; 15(3): 5895-913, 2015 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-25763652

RESUMO

Skylight polarization provides a significant navigation cue for certain polarization-sensitive animals. However, the precision of the angle of polarization (AOP) of skylight for vehicle orientation is not clear. An evaluation of AOP must be performed before it is utilized. This paper reports an evaluation of AOP of skylight by measuring the skylight polarization patterns of clear and cloudy skies using a full-sky imaging polarimetry system. AOP measurements of skylight are compared with the pattern calculated by the single-scattering Rayleigh model and these differences are quantified. The relationship between the degree of polarization (DOP) and the deviation of AOP of skylight is thoroughly studied. Based on these, a solar meridian extracted method is presented. The results of experiments reveal that the DOP is a key parameter to indicate the accuracy of AOP measurements, and all the output solar meridian orientations extracted by our method in both clear and cloudy skies can achieve a high accuracy for vehicle orientation.

20.
Appl Opt ; 53(29): 6735-41, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25322376

RESUMO

Skylight polarization provides a significant navigation cue for certain polarization-sensitive animals. We designed a polarization navigation sensor based on the polarization sensitivity mechanism of insects. In this paper, the principle of our polarization navigation sensor is introduced. The relationship between the degree of polarization (DOP) and the error of the angle of polarization (AOP) is examined. A new DOP and AOP calculation algorithm using a linear least-squares algorithm is presented. The results of simulation and experiments reveal the essentiality of DOP calculation and demonstrate the efficiency and accuracy of the proposed algorithm.

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