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1.
Sci Rep ; 14(1): 11002, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38745014

ABSTRACT

The recommended bearing capacity of medium weathering mudstone foundation is less than the capacity of the rock structure to withstand loads in Southwest China. A comprehensive failure characterization of medium weathering mudstone in Chengdu has been performed including bearing plate test (BPT), binocular vision measurement (BVM) test, uniaxial compressive strength test, trial trench test of shallow rock surface and 3D imaging in this paper. Failure behavior of rock has been modeled with 3D imaging algorithm that utilizes Zhang's calibration method in BVM system combination with trial trench test of shallow rock surface. The bearing capacity of medium weathering mudstone foundation were extracted from uniaxial experiments and BPT-BVM test by fitting relevant material properties to the data. The results revealed that: Bearing capacity of medium weathering mudstone of layered isotropic in Chengdu is undervalued. Specifically, the characteristic load carrying value is in the range 1500-2500 kP, that is 50% higher than in the local standard system. Failure process is different from Hoek-Brown Failure Criterion, presenting a wave peak transfer phenomenon of the increment displacement into the distance. Thus, it can be reduced to that of punching failures for thin bedded structures of Moudstone foundations. Compressive strength of soft rock proves to be main factor limiting the bearing capacity, a clear correlation between the uniaxial compressive strength reduction coefficient and the bearing capacity has been used to establish, leading to the proposal of a load bearing capacity prediction model.

2.
Environ Sci Pollut Res Int ; 30(47): 104886-104900, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37713079

ABSTRACT

The urgent need to address environmental concerns has led to the adoption of green production targets by businesses worldwide. This paper explores the influence of green financing and technological innovation on green e-commerce as companies seek to achieve these targets. The study uses a qualitative research design, employing semi-structured interviews with industry experts to gather data. The findings indicate that green financing has a significant positive effect on adopting green production practices and implementing green technological innovations, positively impacting green e-commerce. To reduce emissions of greenhouse gases and promote long-term economic development, COP 26's guiding principles emphasize the need for robust institutions and environmentally responsible technology innovation. Carbon dioxide (CO2) emissions and associated factors will be analyzed in this research for numerous South Asian nations from 1995 to 2020. Institutional and green technological improvements, alternative energy sources, more accessible commerce, population growth, and economic growth are all examples of such factors. With the possibility of residual cross-sectional dependency and heterogeneity, the research used second-generation panel methodologies to investigate the interrelationships between the variables. Switching to renewable energy sources and implementing environmentally friendly technology innovations have both been shown to cut CO2 emissions by an empirically supported 0.084% and 0.054%, respectively. There is a 0.215 percentage point deterioration in environmental quality due to poor institutional quality, a growing population, increased trade openness, and a thriving economy. The study concludes that achieving green production targets depend on the availability of green financing and the adoption of green technological innovations in the e-commerce industry. This paper provides insights for policymakers, businesses, and investors interested in promoting sustainable business practices and the achievement of green production targets.


Subject(s)
Carbon Dioxide , Inventions , Cross-Sectional Studies , Environment , Commerce , Economic Development , Renewable Energy
3.
ACS Appl Mater Interfaces ; 15(34): 40478-40487, 2023 Aug 30.
Article in English | MEDLINE | ID: mdl-37591494

ABSTRACT

Vapor-phase Beckmann rearrangement of cyclohexanone oxime (CHO) to ε-caprolactam (CPL) is still difficult to commercialize at the industrial scale due to its relatively low catalytic activity and poor lifetime. Herein, we synthesized a series of pure-silicon zeolites (including MFI, MEL, and -SVR) with three-dimensional 10-member-ring topolgies, diverse silanol status, and hierarchical porosity to investigate the synergistic effects of inner diffusivity and reactivity. S-1 zeolite of MFI-type topology with plentiful silanol nests exhibits a more preferable catalytic performance in terms of CHO conversion (99.7%) and CPL selectivity (89.7%), much higher than those of MEL- and -SVR-type zeolites mainly due to their diverse silanol distribution. With the construction of hierarchical porosity, S-1-P shows improved CPL selectivity of 94.1% owing to the enhanced diffusivity to shorten the retention time of the reactant and product molecules. The reaction mechanism and network have been further revealed by density functional theory (DFT) calculations and experimental designs, which indicate that silanol nests are major active sites due to their suitable interaction with CHO rather than terminal silanols. Particularly, the microenvironments of silanols can be modulated by alcohol solvents, ascribed to their different charge transfer and steric hindrance. Consequently, S-1-P shows superior CPL selectivity of 97.3% in ethonal solvents, which have higher adsorb energy of -0.627 eV with silanol nests than other alcohols. The present study not only provides a fundamental guide for the design of zeolite catalysts but also provides a reference for modulating the microenvironment of active sites according to the catalytic mechanism.

4.
Phytother Res ; 37(9): 3939-3950, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37114508

ABSTRACT

The present study aimed to evaluate anti-rheumatoid arthritis (RA) effect of Lonicerin (LON), a safe compound with anti-inflammatory and immunomodulatory properties. Nevertheless, the exact role of LON in RA remains elusive. In this test, the anti-RA effect of LON was evaluated in collagen-induced arthritis (CIA) mouse model. Relevant parameters were measured during the experiment; ankle tissue and serum were collected at the end of the experiment for radiology, histopathology, and inflammation analysis. ELISA, qRT-PCR, immunofluorescence, and western blot were used to explore the effect of LON on the polarization of macrophages and related signal pathways. It was discovered that LON treatment attenuated the disease progression of CIA mice with lower paw swelling, clinical score, mobility, and inflammatory response. LON treatment significantly decreased M1 marker levels in CIA mice and LPS/IFN-γ-induced RAW264.7 cells, while slightly increasing M2 marker levels in CIA mice and IL-4-induced RAW264.7 cells. Mechanistically, LON attenuated the activation of the NF-κB signaling pathway, which contributes to M1 macrophage polarization and inflammasome activation. In addition, LON inhibited NLRP3 inflammasome activation in M1 macrophages, thereby reducing inflammation by inhibiting IL-1ß and IL-18 release. These results indicated that LON might exert anti-RA effects by regulating the polarization of M1/M2 macrophage, especially by inhibiting macrophage polarization toward M1.


Subject(s)
Arthritis, Experimental , Arthritis, Rheumatoid , Mice , Animals , NF-kappa B/metabolism , Arthritis, Experimental/drug therapy , Inflammasomes/metabolism , Macrophages , Signal Transduction , Arthritis, Rheumatoid/drug therapy , Inflammation/metabolism
5.
ACS Omega ; 8(7): 7093-7101, 2023 Feb 21.
Article in English | MEDLINE | ID: mdl-36844522

ABSTRACT

The effect of reaction temperature and weight hourly space velocity (WHSV) on the reaction of 1-decene cracking to ethylene and propylene over H-ZSM-5 zeolite was investigated. Also, the thermal cracking reaction of 1-decene was studied by cracking over quartz sand as blank. It was observed that 1-decene undergoes a significant thermal cracking reaction above 600 °C over quartz sand. In the range of 500-750 °C, the conversion remained above 99% for 1-decene cracking over H-ZSM-5, and the catalytic cracking dominated even at 750 °C. With the increase in temperature, the yields of ethylene and propylene gradually increased, and the yields of alkanes and aromatics also increased. The low WHSV was favorable for the yield of light olefins. With the increase of the WHSV, the yields of ethylene and propylene decrease. However, at low WHSV, secondary reactions were accelerated, and the yields of alkanes and aromatics increased significantly. In addition, the possible main and side reaction routes of the 1-decene cracking reaction were proposed based on product distribution.

6.
J Colloid Interface Sci ; 633: 291-302, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36459934

ABSTRACT

Titanosilicate-1 zeolites (TS-1) as one of the most commonly used catalysts for alkene epoxidation, construction of hierarchical pores as well as elimination of anatase to promote mass transportation and avoid invalid decomposition of hydrogen peroxide are always desirable yet challenging goals. Here, a novel and unique Ti-based metal organic frameworks (MOFs)-induced synthetic strategy for fabricating anatase-free hierarchical TS-1 was first proposed. All the components of MOFs perform different functions: the uniformly distributed Ti nodes replace conventional tetrabutyl titanate (TBOT) to serve as sole Ti source for constructing zeolite crystal; the separated ligands can be embedded in the zeolite framework and act as template to in situ build hierarchical pore structure; the coordination interaction between Ti nodes and ligands can efficiently avoid the anatase generation by balancing the forming rates of Ti-OH and Si-OH. This synthetic strategy is of general applicability, and two different synthetic routes including traditional hydrothermal process and steam assisted crystallization (SAC) procedure are successfully adopted. The obtained hydrothermal TS-1 and SAC anatase-free samples all possess abundant intercrystalline mesopores of 20-50 nm and even macropores between 50 and 150 nm, improving the conversion over 25 % for 1­hexene epoxidation than TS-1 sample prepared by conventional route. The influences of the amount of Ti MOFs precursor and the crystallization process are studied in detail, and possible synthesis mechanisms are proposed. This MOFs-induced strategy might open up an avenue for the rational design of ideal and hierarchical zeolite to boost the catalytic efficiency.

7.
ACS Omega ; 6(27): 17173-17182, 2021 Jul 13.
Article in English | MEDLINE | ID: mdl-34278104

ABSTRACT

The fast deactivation caused by serious formation of coke is a major challenge in catalytic isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) into exo-tetrahydrodicyclopentadiene (exo-THDCPD) over the HY zeolite. In order to suppress the coke formation for the isomerization process, the conventional HY zeolite was modified with Pt at 0.3 wt %. Then, the hydroisomerization of endo-THDCPD into exo-THDCPD was evaluated over a fixed-bed reactor. The catalytic stability of Pt/HY was greatly enhanced in comparison to that of the HY zeolite. The Pt/HY catalyst provided 97% endo-THDCPD conversion and 96% selectivity for exo-THDCPD without deactivation after 100 h. Moreover, the formation mechanism of coke on the HY zeolite during the isomerization process was proposed based on the results of the coke analysis. It was indicated that the coke was generated from the oligomerization and condensation of olefin species, which originated from the ß-scission reaction or hydride transfer reaction of intermediates. The lower coke formation over Pt/HY was attributed to the lower amount of coke precursors, which could be hydrogenated by activated H2 over Pt sites. Therefore, Pt on Pt/HY and H2 were two crucial factors in efficiently enhancing the catalytic stability of the HY zeolite for this isomerization reaction.

8.
RSC Adv ; 11(30): 18288-18298, 2021 May 19.
Article in English | MEDLINE | ID: mdl-35480899

ABSTRACT

Ethylbenzene (EB) is an important bulk chemical intermediate. The vapor-phase process is considered to be more efficient than the liquid-phase process when using dilute ethylene (e.g. FCC or DCC off-gas) as the feed due to its high ethylene space velocity. However, realizing a balance between reducing the xylene formation and enhancing the EB selectivity is still a challenge due to the poor performance of ZSM-5 at low reaction temperature. This study concerns an IM-5 zeolite (IMF topology) modified by H2SiF6, with 89% ethylbenzene selectivity, 98.6% total EB + DEB selectivity and only 540 ppm of xylene at 330 °C. IM-5 zeolites with different Si/Al2 ratios (40-170) were prepared by H2SiF6 modification and their catalytic performance in vapor phase alkylation of benzene with ethylene was investigated. There was an obvious decrease in the acid sites and acid strength of IM-5 in the H2SiF6 treatment process, which led to a slight decrease in ethylbenzene selectivity and a significant decline in xylene yield. Under the conditions of complete ethylene conversion, the selectivity to EB + DEB increased from 96.1% to 98.6% in the parent I-40 and modified IM-5. Compared with ZSM-5 that has a similar acidity, the slightly bigger channel opening makes IM-5 more conductive to the formation and diffusion of DEB while xylene may present adverse effects. The 120 hour-lifetime test showed that IM-5 (I-110) has superior activity, equivalent stability, higher DEB selectivity and a much lower xylene selectivity in comparison with ZSM-5. The catalytic performance of the IM-5 zeolite in the vapor phase process provides a new choice for the production of ethylbenzene.

9.
RSC Adv ; 10(49): 29068-29076, 2020 Aug 05.
Article in English | MEDLINE | ID: mdl-35521147

ABSTRACT

Different amounts of SiO2 were added to the Al2O3 binders to investigate the binder effect on zeolite Y-based catalysts. The added SiO2 improved the mesopore volume and acidity of the catalysts. Characterization results showed that the catalysts' acid amount increased with increasing the SiO2 amount in the binder, which achieved maximum value when 12% SiO2 was added to the binder. The doped SiO2 in Al2O3 binders improved the Al2O3 phase transformation temperature, which is crucial for Al species to break out of the phase energy and migrate into the zeolite. The lifetime of catalyst Y-Al2O3-12SiO2 is 3.7 times higher than that of Y-Al2O3-0SiO2, and the selectivity of the target products simultaneously improved by 7 percentage point. This work should bring some inspiration to the design and application of zeolite-based catalysts.

10.
Exp Cell Res ; 384(1): 111619, 2019 11 01.
Article in English | MEDLINE | ID: mdl-31525341

ABSTRACT

Osteosarcoma is the most common malignancy of bone that occurs in young adults and children, with a five-year survival rate of 60-70%. Metastasis of osteosarcoma maintains an even poorer prognosis. GREM1 plays an important role in regulating organogenesis, body patterning, and tissue differentiation. However, there are limited studies on GREM1 in osteosarcomas. This study was carried out to characterize the expression and function of GREM1 in osteosarcoma cells, thus extending our understanding of osteosarcoma metastasis. GREM1 expression was detected in hBMSC, hFOB1.19, Saos-2, MG63 and U2OS cell lines using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Gain- and loss-of-function approaches were used to assess the biological function of GREM1 in U2OS cells. The effects of GREM1 on U2OS cell proliferation were examined using the CCK-8 and colony formation assay. Migration and invasion ability were confirmed by the wound healing and Transwell assay, respectively. Flow cytometry was used to analyse the effect of GREM1 on the cell cycle and apoptosis. The expression of GREM1 targets was evaluated by qRT-PCR and western blotting. The expression of GREM1 was significantly downregulated in osteosarcoma. GREM1 overexpression inhibited the proliferation, migration and invasion of U2OS cells. GREM1 overexpression suppressed tumour cell-induced endothelial cell migration and invasion ability. The effect of GREM1 may be transduced through regulation of the BMP target transcription factor inhibitor of MMP-2 and -9 as well as Id1. GREM1 overexpression and knockdown regulates the tumorigenesis of osteosarcoma in vivo. In conclusion, GREM1 is downregulated in osteosarcoma cells, and overexpression of GREM1 inhibits the proliferation, migration, invasion and angiogenesis abilities of osteosarcoma cells in vitro and in vivo.


Subject(s)
Bone Neoplasms/genetics , Cell Movement/genetics , Cell Proliferation/genetics , Intercellular Signaling Peptides and Proteins/genetics , Neovascularization, Pathologic/genetics , Osteosarcoma/genetics , Animals , Apoptosis/genetics , Bone Neoplasms/pathology , Cell Cycle/genetics , Cell Line, Tumor , Down-Regulation/genetics , Gene Expression Regulation, Neoplastic/genetics , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness/genetics , Neoplasm Invasiveness/pathology , Neovascularization, Pathologic/pathology , Osteosarcoma/pathology
11.
Am J Transl Res ; 11(7): 4113-4125, 2019.
Article in English | MEDLINE | ID: mdl-31396322

ABSTRACT

Ossification of the posterior longitudinal ligament (OPLL) manifests as ectopic bone formation in spinal ligament tissue. As revealed by in vitro studies, fibroblasts from patients with OPLL or healthy ligament fibroblasts undergo mechanical stress (MS). We previously demonstrated that a cell-cell junction protein, connexin 43 (Cx43), is significantly up-regulated in OPLL cells and previous data indicated that some proteins related to the endoplasmic reticulum (ER) stress response are elevated during the development of OPLL. The present study utilized gain- and loss-of-function tools to delineate the contribution of the ER stress response within ligament fibroblasts under OPLL-inducing stimuli and the crosstalk between Cx43 signaling and the ER stress response. The ER stress process was augmented by the induction of Cx43 expression in OPLL cells or cells under MS. Cx43 over-expression also promoted ER stress and ossification in OPLL cells. Moreover, the activation of ER stress was accompanied with increased oxidative stress, which was inhibited by Cx43 gene silencing. Cx43 knockdown also improved ER stress-related ossification in OPLL cells. The blockage of ER stress using a chemical compound or small interfering RNA was sufficient to overcome MS-induced ossification in OPLL cells. These findings were further validated in patients with OPLL, as the mRNA levels of Cx43 and PKR-like endoplasmic reticulum kinase (a single-pass type I ER membrane protein kinase), a major transducer of ER stress, were significantly increased compared with non-OPLL subjects. In conclusion, this study demonstrates that ER stress participates in Cx43-related OPLL.

12.
World Neurosurg ; 130: 317-323, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31323405

ABSTRACT

BACKGROUND: To evaluate effectiveness and safety of extended laminoplasty for the treatment of ossification of posterior longitudinal ligament (OPLL) involving the C2 segment. METHODS: A total of 132 cases who accepted laminoplasty for treating the OPLL from 2010 to 2015 were included and divided into Group A (n = 26, with C2 OPLL and C2-C7 laminoplasty), Group B (n = 29, with C2 OPLL and C3-C7 laminoplasty), and Group C (n = 77, without C2 OPLL and had C3-C7 laminoplasty). Clinical and radiologic outcomes were compared among the 3 groups. RESULTS: At the final visit, significant improvements in Japanese Orthopedic Association score, Neck Disability Index, Health-Related Quality-of-Life Short Form 36 Physical Component Summary, and Visual Analog Scale score in neck were observed in all 3 groups. However, all the C2-C7 Cobb angle, C2-C3 Cobb angle, sagittal vertical axis, and number of cases with cervical or segmental kyphosis in the 3 groups were not significantly changed. Although total blood loss, operation time, maximum Visual Analog Scale score in neck, incidence of axial pain, change of C2-C7, or sagittal vertical axis in Group A were all significantly larger than that in Group B or Group C, differences in neurologic recovery rate, Neck Disability Index, Health-Related Quality-of-Life Short Form 36 Physical Component Summary, change of the C2-C3 Cobb angle, and incidence of cervical or segmental malalignment among the 3 groups were not significant at the final visit. CONCLUSIONS: If decompression indication for cases with OPLL involving the C2 segment was appropriate, extended laminoplasty up to the C2 segment could provide satisfactory neurologic recovery and would not accelerate cervical or segmental malalignment progression.


Subject(s)
Cervical Vertebrae/surgery , Laminoplasty , Ossification of Posterior Longitudinal Ligament/surgery , Osteogenesis/physiology , Aged , Decompression, Surgical/methods , Female , Humans , Kyphosis/diagnosis , Kyphosis/surgery , Longitudinal Ligaments/surgery , Male , Middle Aged , Neurosurgical Procedures
13.
Bone ; 127: 305-314, 2019 10.
Article in English | MEDLINE | ID: mdl-31280017

ABSTRACT

Ossification of the posterior longitudinal ligament (OPLL) is the major cause for several deteriorate bone and joint diseases. Its development is a highly organized dynamic process as modulated by various physiological and pathophysiological factors. Both long non-coding RNAs (lncRNAs) and small non-coding RNAs (miRNAs) have been postulated to involve into almost all the biological conditions. Here, we applied high through-put transcriptome screening to unveil lncRNAs highly regulated under OPLL condition. siRNA assay in combination with western blot and quantitative PCR deciphered the lncRNA and miRNA functions in OPLL and their underlying mechanism. Here we identified an lncRNA, named Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) engaged into the development of OPLL by indirectly targeting Connexin 43 (Cx43) gene. As previously reported, Cx43 is one of the main proteins contributing to OPLL partially through enhancing inflammatory signaling. On top of that, we provided another regulatory layer that MALAT1 served as the upstream effector governing the transcription of Cx43 gene. Perturbation of MALAT1 significantly inhibited Cx43 expression, inflammation, and osteogenesis. Mechanistically, in silico analysis and experimental validation both confirmed that microRNA-1 (miR-1) was the mediator connecting MALAT1-Cx43 axis: overexpression of miR-1 diminished Cx43 expression and OPLL process; meanwhile, MALAT1 acted as miR-1 sponge to inhibit its suppressive transcription effect on downstream ossification related genes. Knock-down of MALAT1 released sequestered miR-1, which repressed Cx43 expression and associated OPLL. Likewise, induced OPLL caused by overexpression of MALAT1 can be ameliorated by enhanced miR-1 function, knock-down of Cx43 or inhibition of inflammation. More importantly, further validation using patient ligament samples from non-OPLL and OPLL individuals identified MALAT1-miR-1-Cx43 regulatory axis. Collectively, we found a novel mechanism through lncRNA-miRNA interaction that provides more insights into understanding the development of OPLL.


Subject(s)
Connexin 43/metabolism , MicroRNAs/metabolism , Ossification of Posterior Longitudinal Ligament/genetics , RNA, Long Noncoding/metabolism , Base Sequence , Cell Proliferation/genetics , Cytokines/metabolism , Down-Regulation/genetics , Fibroblasts/metabolism , Fibroblasts/pathology , Gene Deletion , Humans , Inflammation/genetics , MicroRNAs/genetics , Ossification of Posterior Longitudinal Ligament/pathology , Osteogenesis/genetics , RNA, Long Noncoding/genetics , Up-Regulation/genetics
14.
RSC Adv ; 8(66): 37842-37854, 2018 Nov 07.
Article in English | MEDLINE | ID: mdl-35558623

ABSTRACT

Protective desilication of highly siliceous H-ZSM-5 was effectively realized by dissolution and recrystallization in tetraethylammonium hydroxide (TEAOH) solution. With better balance between dissolution of OH- and recrystallization of TEA+, intracrystalline mesopores could be generated by selective dissolution of Si by the drilling effects of TEAOH on the micropores, and then Si species in the mother liquor near the external surface could be recrystallized into ZSM-5 shell. With a significantly reduced diffusion length provided by the intracrystalline mesopores, TEAOH-treated samples exhibited longer lifetime and higher propylene selectivity than the parent H-ZSM-5 zeolite. The mediumly-treated T-16 h sample possessed the longest MTP lifetime of 140 h, 5.6 times that of the parent H-ZSM-5 zeolite. Furthermore, the coke content and adsorbed methyl benzene species on the T-16 h sample were heavier than those on the parent H-ZSM-5 sample, which were related to the intracrystalline mesopore structure.

15.
World Neurosurg ; 110: e815-e822, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29191543

ABSTRACT

BACKGROUND: The treatment of multilevel lumbar degenerative disease (LDD) is complicated and challenging, and the optimal surgical strategy remains controversial. OBJECTIVE: To compare the differences in clinical and radiologic outcomes and in complications after 1-level interbody fusion versus multilevel interbody fusion for the treatment of multilevel LDD. METHODS: A total of 100 patients with multilevel LDD were randomized in a 1:1 ratio into the 1-level interbody fusion group or the multilevel interbody fusion group. Clinical and radiologic results and major complications in the 2 groups were analyzed. Clinical outcomes were assessed using the Visual Analog Scale for radicular and back pain, the Oswestry Disability Index, and the short-form 36 physical score. Clinical status was assessed by the Whitecloud classification. Radiologic evaluation included assessment of lumbar lordosis, pelvic incidence, and sacral slope. RESULTS: There were no significant differences in clinical and radiologic results between the 2 groups. Procedure duration and intraoperative blood loss were significantly greater in the multilevel interbody fusion group than in the 1-level interbody fusion group; the multilevel interbody fusion group also had greater incidences of temporary nerve root palsy, wound infection, and adjacent segment disease. CONCLUSION: A hybrid technique including 1-level interbody fusion and multilevel posterolateral fusion is recommended for patients with multilevel LDD.


Subject(s)
Lumbar Vertebrae/surgery , Spinal Diseases/surgery , Spinal Fusion/methods , Disability Evaluation , Female , Follow-Up Studies , Humans , Lumbar Vertebrae/diagnostic imaging , Male , Middle Aged , Pain/diagnostic imaging , Pain/physiopathology , Pain/surgery , Pelvis/diagnostic imaging , Postoperative Complications , Spinal Diseases/diagnostic imaging , Spinal Diseases/physiopathology , Treatment Outcome
16.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 31(6): 1283-7, 2014 Dec.
Article in Chinese | MEDLINE | ID: mdl-25868245

ABSTRACT

In the design of oral cone beam CT, cooperation between synergic control of X-ray source, real-time acquisition of flat detector and motion of mechanical structure affects the CT image quality. Based on the full analysis of the flat detector's timing signal characteristics, this research was carried out with microprocessor controller (MCU), complex programmable logic device (CPLD), and light couplings to design and realize synchronous exposure control system. To evaluate whether the design of the synchronous exposure control system in this project could reach the required imaging accuracy, we employed the projected images in the system to analyze its stability, linear consistency, signal to noise ratio and precede the FDK construction.


Subject(s)
Cone-Beam Computed Tomography , Radiography, Dental , Phantoms, Imaging
17.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 27(4): 912-5, 2010 Aug.
Article in Chinese | MEDLINE | ID: mdl-20842870

ABSTRACT

This is the design of a mechanical systems for use in the balanceable system of ambulance, which can keep the medical service bed at the ambulance level, whatever the terrain is. A level detector will detect the level state of the bed and turn it to a signal. The central processing unit will use this signal to analyse and control the movement of the motor. By this design (which uses the rolling rail as a drive transmission and makes three supports of the bed go up and down), the bed will keep level. With the use of this design, the balanceable system of ambulance can counteract 35 degrees. The error is controlled within +/- 1 degree. And the response time is within 0.3 s. The method of registration can be effective for keeping the bed at the ambulance level, and for reducing the chance of making the patient get hurt on the way to hospital.


Subject(s)
Ambulances , Robotics/methods , Transportation of Patients , Equipment Design , Humans
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