52 research outputs found

    Application of intraoperative infrared thermography in bypass surgery for adult moyamoya syndrome: A preliminary study

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    Background and objectivesCerebral revascularization surgery is the mainstay of treatment for moyamoya syndrome (MMS) today, and intraoperative determination of the patency of the revascularized vessel is a critical factor in the success of the procedure. Currently, major imaging modalities include intraoperative indocyanine green (ICG) videoangiography (ICG-VA), digital subtraction angiography (DSA), and vascular ultrasound Doppler. Infrared thermography is a modern imaging modality with non-contact devices for the acquisition and analysis of thermal data. We aimed to investigate the feasibility and advantages of infrared thermography in determining anastomotic patency during MMS surgery.MethodsIndocyanine green videoangiography and infrared thermography were performed simultaneously in 21 patients with MMS who underwent bypass surgery. The detection result of vessel patency was compared, and the feasibility and advantages of infrared thermography were assessed.ResultsThe patency of the anastomosis was accurately determined in 21 patients using either ICG angiography or infrared thermography. In 20 patients, the results of infrared thermography showed that the vascular anastomosis was unobstructed, and there was an agreement with the subsequent results of ICG-VA. In one patient, we suspected inadequate patency after testing the anastomosis with infrared thermography, and the results of ICG-VA evaluation of the anastomosis confirmed that there was indeed an anastomotic obstruction.ConclusionCompared with ICG-VA, infrared thermography might offer an alternative non-invasive, contrast-free option in assessing anastomosis patency compared with ICG-VA, and it is likely to become more widely used in the clinic in the near future

    CRL4 antagonizes SCFFbxo7-mediated turnover of cereblon and BK channel to regulate learning and memory

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    Intellectual disability (ID), one of the most common human developmental disorders, can be caused by genetic mutations in Cullin 4B (Cul4B) and cereblon (CRBN). CRBN is a substrate receptor for the Cul4A/B-DDB1 ubiquitin ligase (CRL4) and can target voltage- and calcium-activated BK channel for ER retention. Here we report that ID-associated CRL4CRBNmutations abolish the interaction of the BK channel with CRL4, and redirect the BK channel to the SCFFbxo7ubiquitin ligase for proteasomal degradation. Glioma cell lines harbouring CRBN mutations record density-dependent decrease of BK currents, which can be restored by blocking Cullin ubiquitin ligase activity. Importantly, mice with neuron-specific deletion of DDB1 or CRBN express reduced BK protein levels in the brain, and exhibit similar impairment in learning and memory, a deficit that can be partially rescued by activating the BK channel. Our results reveal a competitive targeting of the BK channel by two ubiquitin ligases to achieve exquisite control of its stability, and support changes in neuronal excitability as a common pathogenic mechanism underlying CRL4CRBN–associated ID

    Complex trapezoid grating for light trapping in thin-film solar cells: super-fine structure

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    The research of the optimal surface structure has attracted considerable interest because of its potential application in light trapping in thin-film solar cells (TFSCs). In this paper, a super-fine structure named complex trapezoid grating is proposed to improve the optical absorption comparing to the conventional simple trapezoid grating in a-Si:H TFSCs. The numerical calculation by utilizing rigorous coupled-wave analysis (RCWA) is conducted to obtain the optical absorption of the structured surface. The results demonstrate that, compared to a planar slab, the optimized-simple trapezoid grating shows 97% enhancement of power conversion efficiency η while the complex trapezoid grating shows 131% enhancement. Obviously, the complex trapezoid grating exhibits a better performance than the simple grating, which is due to the perfect antireflective effect and microcavity resonance effect. The angular response of the optical absorption in a-Si:H TFSCs was also investigated. The results further indicate that it is a better way to select the complex trapezoid grating in improving the optical absorption of silicon-based TFSCs

    Involvement of I(h) in dopamine modulation of tonic firing in striatal cholinergic interneurons

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    Striatal cholinergic interneurons are tonically active neurons and respond to sensory stimuli by transiently suppressing firing that is associated with sensorimotor learning. The pause in tonic firing is dependent on dopaminergic activity; however, its cellular mechanisms remain unclear. Here, we report evidence that dopaminergic inhibition of hyperpolarization-activated cation current (I(h)) is involved in this process. In neurons exhibiting regular firing in vitro, exogenous application of dopamine caused a prolongation of the depolarization-induced pause and an increase in the duration of slow afterhyperpolarization (sAHP) after depolarization. Partially blocking I(h) with specific blocker ZD7288 (4-ethylphenylamino-1,2-dimethyl-6-methylaminopyrimidinium chloride) reduced firing and mimicked the effects of dopamine on sAHP. The I(h), being active at membrane potentials negative than -50 mV, was inhibited by dopamine via activation of the D2-like receptor, but not D1-like receptor. The inhibitory effects of the D2 receptor activation on I(h) were mediated through a protein kinase A-independent cyclic AMP pathway. Consistently, D2-like receptor agonist quinpirole showed comparable effects on sAHP and firing rate as those induced by I(h) channel blocker. Moreover, dopamine was unable to further affect the sAHP duration in neurons when I(h) was blocked. These findings indicate that D2 receptor-dependent inhibition of I(h) may be a novel mechanism for modulating the pause response in tonic firing in cholinergic interneurons

    Involvement of I(h) in dopamine modulation of tonic firing in striatal cholinergic interneurons

    No full text
    Striatal cholinergic interneurons are tonically active neurons and respond to sensory stimuli by transiently suppressing firing that is associated with sensorimotor learning. The pause in tonic firing is dependent on dopaminergic activity; however, its cellular mechanisms remain unclear. Here, we report evidence that dopaminergic inhibition of hyperpolarization-activated cation current (I(h)) is involved in this process. In neurons exhibiting regular firing in vitro, exogenous application of dopamine caused a prolongation of the depolarization-induced pause and an increase in the duration of slow afterhyperpolarization (sAHP) after depolarization. Partially blocking I(h) with specific blocker ZD7288 (4-ethylphenylamino-1,2-dimethyl-6-methylaminopyrimidinium chloride) reduced firing and mimicked the effects of dopamine on sAHP. The I(h), being active at membrane potentials negative than -50 mV, was inhibited by dopamine via activation of the D2-like receptor, but not D1-like receptor. The inhibitory effects of the D2 receptor activation on I(h) were mediated through a protein kinase A-independent cyclic AMP pathway. Consistently, D2-like receptor agonist quinpirole showed comparable effects on sAHP and firing rate as those induced by I(h) channel blocker. Moreover, dopamine was unable to further affect the sAHP duration in neurons when I(h) was blocked. These findings indicate that D2 receptor-dependent inhibition of I(h) may be a novel mechanism for modulating the pause response in tonic firing in cholinergic interneurons

    Evaluation of adaptation of the polylactic acid pattern of maxillary complete dentures fabricated by fused deposition modelling technology: A pilot study.

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    OBJECTIVE:To quantitatively evaluate maxillary complete dentures fabricated from polylactic acid (PLA) using fused deposition modelling (FDM) technology. METHODS:A digital maxillary complete denture was prepared based on a standard maxillary edentulous plaster model. The PLA pattern was printed by a FDM machine, with 5 repetitions, while another 5 wax patterns were printed as control group, using a high accuracy three-dimensional (3D) wax printer. The patterns were scanned with a 3D scanner. A light-body silicone film was made after each denture pattern had been totally seated on the plaster model, and was scanned to determine its thickness, which reflected the 3D space between the plaster model and the tissue surface of the denture pattern. The overall area was separated into four parts: primary stress-bearing area, secondary stress-bearing area, border seal area and relief area, and the average deviation of these four parts were measured. The values were analyzed by independent t-test. RESULTS:The overall mean value and standard deviation of space between PLA denture patterns and plaster model was 0.277 ± 0.021 mm, while that of the wax denture patterns was 0.279 ± 0.045 mm, which showed a good fit overall. No statistically significant ( > 0.05) difference was observed between the PLA patterns and wax patterns. CONCLUSIONS:The adaptation of the PLA pattern of maxillary complete denture printed by FDM technology is comparable to that prepared by wax printer, and can satisfy the accuracy requirements

    Clinical application of 4% sodium citrate and heparin in the locking of central venous catheters (excluding dialysis catheters) in intensive care unit patients: A pragmatic randomized controlled trial.

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    ObjectivesThe feasibility of utilizing 4% sodium citrate as an alternative locking solution for central venous catheters (CVCs) (excluding dialysis catheters) was assessed.MethodsUsing heparin saline and 4% sodium citrate as locking solution, then 152 patients in ICU undergoing infusion with central venous catheters, were randomly assigned to receive either 10 U/mL heparin saline or 4% sodium citrate. The used outcome indicators include: four indexes of blood coagulation at 10 minutes after locking and 7 d after the first locking, bleeding around the puncture site and subcutaneous hematoma rate, gastrointestinal bleeding rate, catheter indwelling time, catheter occlusion rate, catheter-related bloodstream infection (CRBSI) rate, rate of ionized calcium ResultsAmong the main outcome measures, the heparin group showed a significant increase in APTT compared to the sodium citrate group at 10 min after locking (LSMD = 8.15, 95%Cl 7.1 to 9.2, P ConclusionsIn ICU patients using CVCs (excluding dialysis catheters) infusion, employing 4% sodium citrate as a locking liquid can reduce the risk of bleeding and catheter occlusion without any hypocalcemia
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