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1.
J Nanosci Nanotechnol ; 20(4): 2408-2415, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492255

RESUMO

New synthetic method toward carbon supported catalysts with improved performance is of great importance in direct alcohol fuel cells (DAFCs). Herein, onion-like nanocarbons (OLNCs) were fabricated by using cheap and readily available candle as the raw material. And a facile one-pot and surfactant-free solvothermal approach was developed for the fabrication of PtSn nanoparticles supported on the OLNCs. Transmission electron microscopy (TEM) images showed the highly crystalline PtSn nanoparticles with size of ~2-5 nm were evenly deposited on the surface of the OLNCs. The obtained PtSn/OLNCs nanocomposites with Pt loading of about 10.1% exhibited excellent electrocatalytic activity toward both methanol oxidation reactions (MOR) and ethylene glycol oxidation reactions (EGOR). The current density of PtSn/OLNCs is 2.6 and 2.7 times of the commercial 20 wt% Pt/C toward the MOR and EGOR, respectively, suggesting the great application potential of the PtSn/OLNCs catalyst in DAFCs. The highly electrocatalytic activity of the PtSn/OLNCs may arise from the ultra-small size of the PtSn NPs as well as the large surface area and good electric conductivity of the OLNCs support. This study not only provides an example of the cost-effective fabrication and application of the OLNCs based catalysts and also sheds a new light on the application of the PtSn/OLNCs catalyst in DAFS.

2.
J Craniofac Surg ; 30(8): 2451-2455, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31689729

RESUMO

OBJECTIVE: To evaluate the morphological changes of the upper airway of patients with skeletal Class III malocclusion after undergoing bilateral mandibular ramus dislocated mandibular retrogression (SSRO) or SSRO combined with Le Fort I maxillary osteotomy and 3-dimensional imaging. METHODS: All previous studies related to the upper airway in patients with skeletal class III malocclusion and orthognathic surgery were collected from the PubMed, EMB, Cochrane Library, Web of science, ClinicalKey, EBSCO, Weipu, Wanfang, China National Knowledge Infrastructure, and Chinese BioMedical Literature databases. The search date ends in August 2017. RevMan5.3 software was used to perform a meta-analysis related to upper airway morphology. Ten studies were included. RESULTS: The meta-analysis showed that 6 months after SSRO, CV1, and CV2 did not change significantly (P >0.05), whereas CV3 and CV4 narrowed (P <0.05) and remained narrow after 1 year (P <0.05). (CV1,CV2,CV3,CV4: Plans parallel to the FH plane passing through the most anterior inferior point of the anterior arch of the atlas, the 2nd cervical vertebra, the 3rd cervical vertebra, the 4th cervical vertebra.) There was no significant change in nasopharyngeal volume or laryngeal pharyngeal volume (P >0.05), but oropharyngeal volume and total volume decreased (P ≤0.01). Six months after SSRO combined with Le Fort I maxillary osteotomy, the minimum cross-sectional area of the upper airway was smaller (P <0.05), there was no significant change in nasopharyngeal volume or oropharyngeal volume (P >0.05), and oropharynx volume and total volume decreased (P <0.05). CONCLUSIONS: Single and double jaw surgery has no significant effect on nasopharynx and oropharynx, but reduces laryngopharynx and total volume; however, whether this will result in postoperative obstructive sleep apnea-hypopnea syndrome or become ameliorated over time requires more in-depth study and a longer period of clinical observation.

3.
Medicine (Baltimore) ; 98(44): e17785, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31689850

RESUMO

INTRODUCTION: Cerebrovascular imaging is the gold standard for diagnosis of intracranial aneurysms. Rupture of intracranial aneurysm is rare in cerebrovascular angiography, especially in unruptured intracranial aneurysm. PATIENT CONCERNS: A 74-year-old woman was admitted to the hospital for sudden onset of left eyelid ptosis for 1 day with no obvious inducement. The patient had a history of hypertension. Physical examination revealed that she had clear consciousness and normal speech, but the left eyelid drooped. The left pupil diameter was 5 mm and light reflex was absent. The left eyeball could not move, and the right eye examinations were normal. The limb muscle strength and muscle tension were normal. DIAGNOSIS: Bilateral internal carotid artery posterior communicating aneurysm, severe stenosis of the origin of left carotid artery, and right oculomotor nerve palsy. INTERVENTIONS: After the hospital, the aneurysm ruptured and hemorrhaged during radiography, and the patient improved after immediate rescue and treatment. On the third day after angiography, the patient's the condition gradually stabilized. Under the general anesthesia, left carotid artery stenosis stent implantation and left posterior communicating artery aneurysm stent assisted coil embolization were performed successfully. On the second day after embolization, the patient's head computed tomography (CT) showed subarachnoid hemorrhage with hydrocephalus. The patient underwent external ventricular drainage. A month later, the patient underwent ventriculoperitoneal shunt. OUTCOMES: Six months later, the patient visited our hospital for a follow-up, and she was clear-headed, aphasia, right limb hemiplegia with muscle strength grade II, left side autonomous activities, and the GOS score was 2 points. Head CT showed the ventricles were normal. CONCLUSIONS: Acute oculomotor palsy may be a risk factor for rupture of ipsilateral unruptured aneurysms, but more basic research and clinical trial evidence of intracranial aneurysms are needed to confirm this.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31676481

RESUMO

Dietary fiber provides growth substrates for bacterial species that belong to the colonic microbiota of humans. The microbiota degrades and ferments substrates, producing characteristic short chain fatty acid profiles. Dietary fibre contains plant cell wall-associated polysaccharides (hemicelluloses, pectins) that are chemically diverse in composition and structure. Thus, depending on plant sources, dietary fiber daily presents the microbiota with mixtures of plant polysaccharides of varying types and complexity. We studied the extent and preferential order in which mixtures of plant polysaccharides (arabinoxylan, xyloglucan, ß-glucan, pectin) were utilized by a co-culture of five bacterial species (Bacteroides ovatus, Bifidobacterium longum subspecies longum, Megasphaera elsdenii, Ruminococcus gnavus, Veillonella parvula). These species are members of the human gut microbiota and have the biochemical capacity, collectively, to degrade and ferment the polysaccharides, and produce short chain fatty acids (SCFAs). B. ovatus utilized glycans in the order ß-glucan: pectin: xyloglucan: arabinoxylan, whereas B. longum subsp. longum utilization was in the order arabinoxylan: arabinan: pectin: ß-glucan. Propionate, as a proportion of total SCFAs, was augmented when polysaccharide mixtures contained galactan, resulting in greater succinate production by B. ovatus and conversion of succinate to propionate by V. parvula Overall, we derived a synthetic ecological community that carries out SCFA production by the common pathways used by bacterial species for this purpose. Use of systems like this might be used to predict changes to the emergent properties of the gut ecosystem when diet is altered, with the aim of beneficially affecting human physiology.Importance. This study addresses the question as to how bacterial species, characteristic of the human gut microbiota, collectively utilize mixtures of plant polysaccharides such as are found in dietary fiber. Five bacterial species with the capacity to degrade polymers and/or produce acidic fermentation products detectable in human feces were used in the experiments. The bacteria showed preferential use of certain polysaccharides over others for growth, and this influenced their fermentation output qualitatively. These kinds of studies are essential in developing concepts of how the gut microbial community shares habitat resources, directly and indirectly, when presented with mixtures of polysaccharides that are found in human diets. The concepts are required in planning dietary interventions that might correct imbalances in the functioning of the human microbiota so as to support measures to reduce metabolic conditions such as obesity.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31677195

RESUMO

BACKGROUND AND AIM: Patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M (rs738409) genotype influences clinical/biochemical characteristics in patients with nonalcoholic fatty liver disease (NAFLD), but whether PNPLA3-I148M (rs738409) genotype also influences the diagnostic performance of non-invasive diagnostic tests for NAFLD is uncertain. Our aim was to investigate the differences in diagnostic performance of non-invasive diagnostic tests for NAFLD according to PNPLA3-I148M (rs738409) genotype. METHODS: 58 healthy controls and 349 patients with biopsy-proven NAFLD were included. Areas under operating characteristics (AUROCs) were calculated for predicting hepatic steatosis [fatty liver index (FLI), hepatic steatosis index (HSI)]; NASH [cytokeratin-18 (CK18) M30 and M65] and significant fibrosis (≥F2 fibrosis) [Fibrosis-4 (FIB-4) and BARD], stratifying by rs738409 genotypes (CC and CG+GG groups). RESULTS: FLI and HSI showed good diagnostic performance for diagnosing steatosis only in the CG+GG group with AUROCs ranging from 0.819 to 0.832 respectively. CK18 M30 (AUROC=0.688) and M65 (AUROC=0.678) had suboptimal performance for diagnosing NASH in the CG+GG group, whereas both had good performance (AUROC=0.814 and 0.813, respectively) in the CC group. BARD score showed good performance in the CG+GG group compared to the CC group (AUROC=0.805 and 0.532, respectively). FIB-4 had suboptimal performance in the CG+GG group, and good performance in the CC group (AUROC =0.662 and 0.801, respectively). CONCLUSIONS: Diagnostic performance of non-invasive tests for NAFLD varied markedly according to PNPLA3 genotypes. Clinicians should be aware that PNPLA3 genotype limits the clinical utility of non-invasive diagnostic tests for diagnosing NAFLD.

6.
J Adv Nurs ; 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31667860

RESUMO

AIM: To systematically review the effectiveness of vinegar consumption in improving glycemic control in adults with type 2 diabetes mellitus. DESIGN: A systematic review and meta-analysis. REVIEW SOURCES: The CINAHL, Excerpta Medica database (EMBASE), Medline, PubMed, Scopus and Cochrane databases were searched in April 2019. Interventional studies published in the English language, from inception to 15 April 2019, were included. REVIEW METHODS: Two investigators independently assessed the quality of the studies, discussed their findings to reach consensus, and complied with the standards of the Cochrane. Handbook for Systematic Reviews of Interventions. Random-effects meta-analysis was conducted in Review Manager 5.3.5 to assess the effect size. A series of subgroup and sensitivity analyses were conducted to explore the causes of heterogeneity. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: A total of 6 relevant studies, including 317 patients with type 2 diabetes mellitus, were selected from 356 studies identified through electronic searches and reference lists. The meta-analysis showed significantly better fasting blood glucose and hemoglobin A1c (HbA1c) level. In secondary analyses, there was a remarkable reduction in total cholesterol and low-density lipoprotein postintervention. CONCLUSION: Vinegar content varied across the studies, and the sample sizes in the included studies were relatively small. Therefore, caution should be exercised when trying to extrapolate the results to a larger population. IMPACT: Existing reviews are limited to narrative synthesis, lacking critical appraisal, heterogenous outcomes, nor any report of fasting blood glucose and HbA1c. This meta-analysis review extends the evidence on the beneficial effects of vinegar on glycemic control as measured by HbA1c and fasting blood glucose. Clinicians could incorporate vinegar consumption as part of their dietary advice for patients with diabetes.

9.
Nurse Educ Today ; 84: 104215, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31683138

RESUMO

BACKGROUND: Registered Nurse Preceptors guide students to integrate theory into practice, assess clinical competencies, and enhance problem-solving skills. Researches have indicated that the teaching competencies of nurse preceptors can be transferred to students' clinical learning. OBJECTIVES: The aims of the study are to develop a web-based clinical pedagogy (WCP) program for Registered Nurse Preceptors and conduct pilot program evaluation. DESIGN: A three-step process was applied to integrate the theoretical framework, evidence from the systematic review, and content validity by the experts and pilot test with the Registered Nurse Preceptors in the content and technical development of the program. The WCP program has unique features including use of dashboard, interactive videos, consultation with experts, discussion forum and backend data analysis. RESULTS: A committee of six content experts evaluated the comprehensiveness, appropriateness, and relevancy of the program. The item-Content Validity Index (CVI) score ranged from 0.83 to 1.00 and the scale-CVI score was 0.87, which indicated that the WCP program had a strong content validity. Ten nurse preceptors were invited to use the WCP program. Preceptors shared that the website was easy to use and navigate. They commented that the videos in each module are beneficial for nurses to understand the real situation in the clinical setting. This feature also makes the website more interactive. Feedback from preceptors was subsequently used to further refine the program. DISCUSSION AND CONCLUSION: The WCP program is an evidence-based program that provides a comprehensive coverage on clinical teaching pedagogy and assessment strategies. The unique web-based technology and interactive features provide a platform for nurse preceptors to discuss clinical encounters with peers and consult experts. The flexible and resource-rich nature of web-based learning encourages nurses to use it for continuing education.

10.
Biomed Pharmacother ; 121: 109310, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31710895

RESUMO

Currently, there is no effective method to prevent renal interstitial fibrosis after acute kidney injury (AKI). In this study, we established and screened a new renal interstitial fibrosis rat model after cisplatin-induced AKI. Our results indicated that rats injected with 4 mg/kg cisplatin once a week for two weeks after firstly administrated with 6.5 mg/kg loading dose of cisplatin could set up a more accurate model reflecting AKI progression to renal interstitial fibrosis. Then, we investigated the effects and possible mechanisms of human umbilical cord blood mononuclear cells (hUCBMNCs) on renal tubular interstitial fibrosis after cisplatin-induced AKI. In rats injected with hUCBMNCs for four times, level of matrix metalloproteinase 7(MMP-7)in serum and urine, urinary albumin/creatinine ratio, tubular pathological scores, the relative collagen area of the tubulointerstitial region, endoplasmic reticulum dilation and the mitochondrial ultrastructural damage were significantly improved. The level of reactive oxygen species, α-smooth muscle actin (α-SMA), [NOD]-like pyrin domain containing protein 3 and cleaved-Caspase 3 in renal tissue decreased significantly. However, in rats injected with hUCBMNCs for two times, no significant difference was discovered in MMP-7 levels and urinary albumin/creatinine ratio. Although expression of α-SMA and the percentage areas of collagen staining in tubulointerstitial tissues were ameliorated in rats injected with hUCBMNCs for two times, the effects were significantly weaker than those in rats injected with hUCBMNCs for four times. Taken together, our study constructed a highly efficient, duplicable novel rat model of renal fibrosis after cisplatin-induced AKI. Multiple injections of hUCBMNCs may prevent renal interstitial fibrosis after cisplatin-induced AKI.

11.
Biomed Pharmacother ; 121: 109595, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31710896

RESUMO

Pyroptosis is an inflammatory form of cell death triggered by certain inflammasomes, leading to the cleavage of gasdermin D (GSDMD) and activation of inactive cytokines like IL-18 and IL-1ß. Pyroptosis has been reported to be closely associated to some diseases like atherosclerosis and diabetic nephropathy. Recently, some studies found that pyroptosis can influence the proliferation, invasion and metastasis of tumor, which regulated by some non-coding RNAs and other molecules. Hence, we provided an overview of morphological and molecular characteristics of pyroptosis. We also focus on mechanism of regulating pyroptosis in tumor cells as well as the potential roles of pyroptosis in cancer to explore potential diagnostic markers in cancers contributing to the prevention and treatment in cancers.

12.
Artigo em Inglês | MEDLINE | ID: mdl-31721428

RESUMO

BACKGROUND: Tele-coaching has been used by nurses as one of the accessible and sustainable interventions for individuals with type 2 diabetes mellitus. However, evidence has been lacking to demonstrate its effectiveness in mitigating the related cardiovascular risk factors. AIMS: To systematically evaluate the effectiveness of nurse-led tele-coaching on the modifiable cardiovascular risk factors (glycated hemoglobin, blood pressure, & lipid levels) among individuals with type 2 diabetes mellitus. METHODS: A systematic search of eight databases (Cochrane Library, PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, Scopus, PsycINFO, Web of Science, & ProQuest Dissertations and Theses) was conducted for randomized controlled trials of nurse-led tele-coaching for individuals with type 2 diabetes mellitus published in English up to October 30, 2018. A meta-analysis was conducted for the primary outcomes of the studies. RESULTS: Twelve randomized controlled trials were selected that included 3,030 participants. Results from the meta-analysis revealed statistically significant reductions for not only glycated hemoglobin (pooled mean difference = -1.23, 95% CI: -1.63 to -0.8, I2  = 0%, p < .00) but also systolic blood pressure (SBP; pooled mean difference = -2.22, 95% CI: -3.95 to -0.49, I2  = 0%, p < .01); such findings are supportive of the use of nurse-led tele-coaching on the primary outcome. LINKING EVIDENCE TO ACTION: Results from the meta-analyses have shown that nurse-led tele-coaching is an effective and accessible intervention that could improve the glycemic control and SBP among individuals with type 2 diabetes mellitus.

13.
Med Phys ; 2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31605627

RESUMO

PURPOSE: Segmentation of the left ventricle (LV), right ventricle (RV) cavities and the myocardium (MYO) from cine cardiac magnetic resonance (MR) images is an important step for diagnosis and monitoring cardiac diseases. Spatial context information may be highly beneficial for segmentation performance improvement. To this end, this paper proposes an iterative multi-path fully convolutional network (IMFCN) to effectively leverage spatial context for automatic cardiac segmentation in cine MR images. METHODS: To effectively leverage spatial context information, the proposed IMFCN explicitly models the interslice spatial correlations using a multi-path late fusion strategy. First, the contextual inputs including both the adjacent slices and the already predicted mask of the above adjacent slice are processed by independent feature-extraction paths. Then, an atrous spatial pyramid pooling (ASPP) module is employed at the feature fusion process to combine the extracted high-level contextual features in a more effective way. Finally, deep supervision (DS) and batch-wise class re-weighting mechanism are utilized to enhance the training of the proposed network. RESULTS: The proposed IMFCN was evaluated and analyzed on the MICCAI 2017 automatic cardiac diagnosis challenge (ACDC) dataset. On the held-out training dataset reserved for testing, our method effectively improved its counterparts that without spatial context and that with spatial context but using an early fusion strategy. On the 50 subjects test dataset, our method achieved Dice similarity coefficient of 0.935, 0.920, and 0.905, and Hausdorff distance of 7.66, 12.10, and 8.80 mm for LV, RV, and MYO, respectively, which are comparable or even better than the state-of-the-art methods of ACDC Challenge. In addition, to explore the applicability to other datasets, the proposed IMFCN was retrained on the Sunnybrook dataset for LV segmentation and also produced comparable performance to the state-of-the-art methods. CONCLUSIONS: We have presented an automatic end-to-end fully convolutional architecture for accurate cardiac segmentation. The proposed method provides an effective way to leverage spatial context in a two-dimensional manner and results in precise and consistent segmentation results.

14.
Chem Commun (Camb) ; 55(84): 12627-12630, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31580342

RESUMO

A porous NiFe (oxy)hydroxide catalyst fabricated on n+pp+-Si/Ni/NiOx, which is converted from an electrodeposited NiFe oxysulfide, allows a silicon photoanode for water splitting to hit a record 5.1% efficiency with good stability of up to 135 h under 40 mA cm-2 in 1.0 M NaOH.

15.
J Phys Chem Lett ; 10(21): 6551-6557, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31597421

RESUMO

Cobalt-nitrogen-functionalized materials have been recognized as promising catalysts for the CO2 reduction reaction because of their superior activity. In order to further improve their activity, we proposed an optimization method through coordination engineering in cobalt-nitrogen-functionalized porphyrin and graphene. By considering a series of derived structures with coordinating nitrogen atoms substituted by carbon or oxygen atoms, a clear activity trend is obtained by constructing a volcano-type plot for activity against adsorption energies of *CO. Detailed electronic structure analysis shows that the enhanced catalytic activity is due to the lacking of π bonding in Co-O bonds compared to Co-C or Co-N bonds in cobalt-centered motifs. This difference allows us to predict the catalytic activity by using the vacancy formation energy of the cobalt atom. Our work provides a general guideline for a rational design of efficient catalysts, which may stimulate further study of coordination engineering for other key energy conversion processes.

16.
Plant Mol Biol ; 101(4-5): 507-516, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31617145

RESUMO

KEY MESSAGE: MMDH2 gene negatively regulates Cd tolerance by modulating reactive oxygen species (ROS) levels and the ROS-mediated signaling, thus, affecting the expression of PDR8. The molecular mechanism by which plants respond to stress caused by cadmium (Cd), one of the most toxic heavy metals to plants, is not well understood. Here, we show that MMDH2, a gene encoding mitochondrial malate dehydrogenase, is involved in Cd stress tolerance in Arabidopsis. The expression of MMDH2 was repressed by Cd stress. The mmdh2 knockdown mutants showed enhanced Cd tolerance, while the MMDH2-overexpressing lines were sensitive to Cd. Under normal and Cd stress conditions, lower H2O2 levels were detected in mmdh2 mutant plants than in wild-type plants. In contrast, higher H2O2 levels were found in MMDH2-overexpressing lines, and they were negatively correlated with malondialdehyde levels. In addition, the expression of the PDR8, a gene encoding a Cd efflux pump, increased and decreased in the mmdh2 mutant and MMDH2-overexpressing lines, in association with lower and higher Cd concentrations, respectively. These results suggest that the MMDH2 gene negatively regulates Cd tolerance by modulating reactive oxygen species (ROS) levels and the ROS-mediated signaling, thus, affecting the expression of PDR8.

17.
Opt Lett ; 44(20): 4941-4944, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31613234

RESUMO

We demonstrate, to the best of our knowledge, the first thermally reconfigurable high-Q silicon carbide (SiC) microring resonators with integrated microheaters on a 3C-SiC-on-insulator platform. We extract a thermo-optic coefficient of around 2.67×10-5/K for 3C-SiC from wavelength shift of a resonator heated by a hot plate. Finally, we fabricate a 40-µm-radius microring resonator with intrinsic Q of 139,000 at infrared wavelengths (∼1550 nm) after integration with a NiCr microheater. By applying current through the microheater, a resonance shift of 30 pm/mW is achieved in the microring, corresponding to ∼50 mW per π phase shift. This platform offers an easy and reliable way for integration with electronic devices as well as great potential for diverse integrated optics applications.

18.
Neural Comput ; 31(12): 2368-2389, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31614099

RESUMO

Though succeeding in solving various learning tasks, most existing reinforcement learning (RL) models have failed to take into account the complexity of synaptic plasticity in the neural system. Models implementing reinforcement learning with spiking neurons involve only a single plasticity mechanism. Here, we propose a neural realistic reinforcement learning model that coordinates the plasticities of two types of synapses: stochastic and deterministic. The plasticity of the stochastic synapse is achieved by the hedonistic rule through modulating the release probability of synaptic neurotransmitter, while the plasticity of the deterministic synapse is achieved by a variant of a reward-modulated spike-timing-dependent plasticity rule through modulating the synaptic strengths. We evaluate the proposed learning model on two benchmark tasks: learning a logic gate function and the 19-state random walk problem. Experimental results show that the coordination of diverse synaptic plasticities can make the RL model learn in a rapid and stable form.

19.
Brain ; 142(10): 3099-3115, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504219

RESUMO

The loss-of-function mutation in PARK7/DJ-1 is one of the most common causes of autosomal recessive Parkinson's disease, and patients carrying PARK7 mutations often exhibit both a progressive movement disorder and emotional impairment, such as anxiety. However, the causes of the emotional symptom accompanying PARK7-associated and other forms of Parkinson's disease remain largely unexplored. Using two-photon microscopic Ca2+ imaging in awake PARK7-/- and PARK7+/+ mice, we found that (i) PARK7-/- neurons in the frontal association cortex showed substantially higher circuit activity recorded as spontaneous somatic Ca2+ signals; (ii) both basal and evoked dopamine release remained intact, as determined by both electrochemical dopamine recordings and high performance liquid chromatography in vivo; (iii) D2 receptor expression was significantly decreased in postsynaptic frontal association cortical neurons, and the hyper-neuronal activity were rescued by D2 receptor intervention using either local pharmacology or viral D2 receptor over-expression; and (iv) PARK7-/- mice showed anxiety-like behaviours that were rescued by either local D2 receptor pharmacology or overexpression. Thus, for first time, we demonstrated a robust D2 receptor-dependent phenotype of individual neurons within the prefrontal cortex circuit in awake parkinsonian mice that linked with anxiety. Our work sheds light on early-onset phenotypes and the mechanisms underlying Parkinson's disease by imaging brain circuits in an awake mouse model.

20.
Proc Natl Acad Sci U S A ; 116(40): 20201-20209, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31530723

RESUMO

Action potential-induced vesicular exocytosis is considered exclusively Ca2+ dependent in Katz's Ca2+ hypothesis on synaptic transmission. This long-standing concept gets an exception following the discovery of Ca2+-independent but voltage-dependent secretion (CiVDS) and its molecular mechanisms in dorsal root ganglion sensory neurons. However, whether CiVDS presents only in sensory cells remains elusive. Here, by combining multiple independent recordings, we report that [1] CiVDS robustly presents in the sympathetic nervous system, including sympathetic superior cervical ganglion neurons and slice adrenal chromaffin cells, [2] uses voltage sensors of Ca2+ channels (N-type and novel L-type), and [3] contributes to catecholamine release in both homeostatic and fight-or-flight like states; [4] CiVDS-mediated catecholamine release is faster than that of Ca2+-dependent secretion at the quantal level and [5] increases Ca2+ currents and contractility of cardiac myocytes. Together, CiVDS presents in the sympathetic nervous system with potential physiological functions, including cardiac muscle contractility.

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