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Herein, we studied the combined effects of the magnetic field and the alternating current driven air surface dielectric barrier discharge on ozone production, and found that a 0.13 T perpendicular magnetic field introduced into the discharge area significantly enhanced the ozone generation performance with a 36-108% increase in ozone number density and 24-80% increase in ozone yield depending on discharge voltage and frequency differences. To reveal the micro physico-chemical mechanism of the influence of a magnetic field and discharge parameters of discharge voltage and frequency on ozone generation, a plasma chemical reaction network involving electron collision-chain reactions was considered. The results show that these parameters jointly influence ozone generation by affecting electron collision reactions and chain chemical reactions by changing the mean electron energy and plasma gas temperature. In this study, both the experimental results and mechanism analysis suggested that an optimal discharge parameter for ozone generation is the magnetic field assisted, low frequency, high voltage (6.5 kHz, 6.5 kV) surface dielectric barrier discharge. These insights provide guidance for optimizing the discharge parameters of the magnetic field assisted discharge to increase ozone production and reduce energy consumption.
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Our study aims to investigate the alterations and diagnostic efficiency of regional homogeneity (ReHo) and functional connectivity (FC) in hypertension patients with cognitive impairment. A total of 62 hypertension patients with cognitive impairment (HTN-CI), 59 hypertension patients with normal cognition (HTN-NC), and 58 healthy controls (HCs) with rs-fMRI data were enrolled in this study. Univariate analysis (based on whole-brain ReHo and seed-based FC maps) was performed to observe brain regions with significant differences among the three groups. Multiple voxel pattern analysis (MVPA) was applied to evaluate the diagnostic accuracy in classifying HTN-CI from HTN-NC and HCs. Compared with the HCs and HTN-NC, HTN-CI exhibited decreased ReHo in the right caudate, left postcentral gyrus, posterior cingulate gyrus, insula, while increased ReHo in the left superior occipital gyrus and superior parietal gyrus. HTN-CI showed increased FC between seed regions (left posterior cingulate gyrus, insula, postcentral gyrus) with many specific brain regions. MVPA analysis (based on whole-brain ReHo and seed-based FC maps) displayed high classification ability in distinguishing HTN-CI from HTN-NC and HCs. The ReHo values (right caudate) and the FC values (left postcentral gyrus seed to left posterior cingulate gyrus) were positively correlated with the MoCA scores in HTN-CI. HTN-CI was associated with decreased ReHo and increased FC mainly in the left posterior cingulate gyrus, postcentral gyrus, insula compared to HTN-NC and HC. Besides, MVPA analysis yields excellent diagnostic accuracy in classifying HTN-CI from HTN-NC and HCs. The findings may contribute to unveiling the underlying neuropathological mechanism of HTN-CI.
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Mapeo Encefálico , Disfunción Cognitiva , Humanos , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Disfunción Cognitiva/diagnóstico por imagen , Encéfalo/diagnóstico por imagenRESUMEN
PURPOSE: To investigate the alterations of topological organization of the whole brain functional networks in hypertension patients with cognitive impairment (HTN-CI) and characterize its relationship with cognitive scores. METHODS: Fifty-seven hypertension patients with cognitive impairment and 59 hypertension patients with normal cognition (HTN-NC), and 49 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging. Graph theoretical analysis was used to investigate the altered topological organization of the functional brain networks. The global topological properties and nodal metrics were compared among the three groups. Network-based statistic (NBS) analysis was used to determine the connected subnetwork. The relationships between network metrics and cognitive scores were also characterized. RESULTS: HTN-CI patients exhibited significantly decreased global efficiency, lambda, and increased shortest path length when compared with HCs. In addition, both HTN-CI and HTN-NC groups exhibited altered nodal degree centrality and nodal efficiency in the right precentral gyrus. The disruptions of global network metrics (lambda, Lp) and the nodal metrics (degree centrality and nodal efficiency) in the right precentral gyrus were positively correlated with the MoCA scores in HTN-CI. NBS analysis demonstrated that decreased subnetwork connectivity was present both in the HTN-CI and HTN-NC groups, which were mainly involved in the default mode network, frontoparietal network, and cingulo-opercular network. CONCLUSION: This study demonstrated the alterations of topographical organization and subnetwork connectivity of functional brain networks in HTN-CI. In addition, the global and nodal network properties were correlated with cognitive scores, which may provide useful insights for the understanding of neuropsychological mechanisms underlying HTN-CI.
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Disfunción Cognitiva , Hipertensión , Humanos , Imagen por Resonancia Magnética , Encéfalo/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/complicaciones , Mapeo Encefálico , Hipertensión/complicacionesRESUMEN
Rumination is a common symptom of major depressive disorder (MDD) and has been characterized as a vulnerability factor for the onset or recurrence of MDD. However, the neurobiological mechanisms underlying rumination and appropriate treatment strategies remain unclear. In the current study, we used resting-state functional magnetic resonance imaging to investigate the effects of body-mind relaxation meditation induction (BMRMI) intervention in MDD with rumination. To this aim, we have recruited 25 MDD and 24 healthy controls (HCs). Changes in functional connectivity (FC) of the anterior cingulate cortex (ACC) subregion and the scores of clinical measurements were examined using correlation analysis. At baseline, MDD showed stronger FC between the right dorsal ACC (dACC) and right superior frontal gyrus than did the HC group. Compared to baseline, the HC group showed a significantly enhanced FC between the right dACC and right superior frontal gyrus, and the MDD group demonstrated a significantly weaker FC between the left dACC and right middle frontal gyrus (MFG) after the intervention. Furthermore, the FC between the right dACC and right superior frontal gyrus was positively associated with rumination scores across all participants at baseline. The above results indicate that BMRMI may regulate self-referential processing and cognitive function through modulating FC of the dACC in MDD with rumination.
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Trastorno Depresivo Mayor , Meditación , Trastorno Depresivo Mayor/terapia , Giro del Cíngulo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , DescansoRESUMEN
BACKGROUND: Major depressive disorder (MDD) is a highly prevalent mood disorder, characterized by depressed mood, reduced capabilities to concentrate, impaired cognition, as well as a high risk of relapse. Unaffected siblings who have high risks for MDD development and yet without clinical symptoms may be helpful for understanding the neural mechanisms of MDD traits. METHODS: We investigated both regional fluctuation and inter-regional synchronization in 31 fully remitted MDD patients, 29 unaffected siblings and 43 age, gender, and educational level matched helathy controls (HCs) using resting-state functional magnetic resonance imaging (rs-fMRI). The 17-item HAMD and neurocognitive scales were performed. Fractional amplitude of low-frequency fluctuation (fALFF) and functional connectivity (FC) strength were investigated. RESULTS: Compared with healthy control group, patients with remitted MDD and unaffected siblings showed increased fALFF in the left dorsomedial prefrontal cortex (dmPFC) and increased FC between the left dmPFC and the right ventromedial prefrontal cortex (vmPFC). In addition, a negative correlation was observed between the fALFF value in the left dmPFC and the speed of Trail Making Test in the remitted MDD patients. Higher vmPFC-dmPFC FC was positively correlated with Wisconsin Card Sorting Test (WCST) total correct, and negatively correlated with WCST random errors. CONCLUSIONS: In the absence of clinical symptoms, individuals with remitted MDD and unaffected siblings showed increased fALFF in left dmPFC as well as the vmPFC-dmPFC connectivity. These results suggest a specific trait abnormality in the default mode network associated with vulnerability to MDD, which may have implications for developing effective therapies using this network as a target.
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Trastorno Depresivo Mayor , Encéfalo , Depresión , Humanos , Imagen por Resonancia Magnética/métodos , Corteza Prefrontal/diagnóstico por imagen , RecurrenciaRESUMEN
We have developed a new binary epitope-presenting CVP platform based on bamboo mosaic virus (BaMV) by using the sortase A (SrtA)-mediated ligation technology. The reconstructed BaMV genome harbors two modifications: 1) a coat protein (CP) with N-terminal extension of the tobacco etch virus (TEV) protease recognition site plus 4 extra glycine (G) residues as the SrtA acceptor; and 2) a TEV protease coding region replacing that of the triple-gene-block proteins. Inoculation of such construct, pKB5G, on Nicotiana benthamiana resulted in the efficient production of filamentous CVPs ready for SrtA-mediated ligation with desired proteins. The second part of the binary platform includes an expression vector for the bacterial production of donor proteins. We demonstrated the applicability of the platform by using the recombinant envelope protein domain III (rEDIII) of Japanese encephalitis virus (JEV) as the antigen. Up to 40% of the BaMV CP subunits in each CVP were loaded with rEDIII proteins in 1 min. The rEDIII-presenting BaMV CVPs (BJLPET5G) could be purified using affinity chromatography. Immunization assays confirmed that BJLPET5G could induce the production of neutralizing antibodies against JEV infections. The binary platform could be adapted as a useful alternative for the development and mass production of vaccine candidates.
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Aminoaciltransferasas/metabolismo , Antígenos Virales/administración & dosificación , Proteínas Bacterianas/metabolismo , Cisteína Endopeptidasas/metabolismo , Virus de la Encefalitis Japonesa (Especie)/inmunología , Encefalitis Japonesa/prevención & control , Endopeptidasas/metabolismo , Vacunas contra la Encefalitis Japonesa/administración & dosificación , Potexvirus/enzimología , Virión/enzimología , Aminoaciltransferasas/genética , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Antígenos Virales/genética , Antígenos Virales/inmunología , Proteínas Bacterianas/genética , Línea Celular , Cisteína Endopeptidasas/genética , Modelos Animales de Enfermedad , Virus de la Encefalitis Japonesa (Especie)/genética , Encefalitis Japonesa/sangre , Encefalitis Japonesa/inmunología , Encefalitis Japonesa/virología , Endopeptidasas/genética , Escherichia coli/genética , Escherichia coli/inmunología , Escherichia coli/metabolismo , Femenino , Vectores Genéticos , Inmunogenicidad Vacunal , Vacunas contra la Encefalitis Japonesa/genética , Vacunas contra la Encefalitis Japonesa/inmunología , Ratones Endogámicos BALB C , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/inmunología , Plantas Modificadas Genéticamente/metabolismo , Potexvirus/genética , Potexvirus/inmunología , Nicotiana/genética , Nicotiana/inmunología , Nicotiana/metabolismo , Virión/genética , Virión/inmunologíaRESUMEN
It is estimated that 50% of patients with colorectal cancer will develop liver metastasis. Surgical resection significantly improves survival and provides a chance of cure for patients with colorectal cancer liver metastasis (CRLM). Increasing the resectability of primary unresectable liver metastasis provides more survival benefit for those patients. Considerable surgical innovations have been made to increase the resection rate and decrease the potential risk of hepatic failure postoperation. Liver transplantation (LT) has been explored as a potential curative treatment for unresectable CRLM. However, candidate selection criteria, chemotherapy strategies, refined immunity regimens and resolution for the shortage of grafts are lacking. This manuscript discusses views on surgical indication, peritransplantation anti-tumor and anti-immunity therapy and updated advances in LT for unresectable CRLM. A literature review of published articles and registered clinical trials in PubMed, Google Scholar, and Clinicaltrials.gov was performed to identify studies related to LT for CRLM. Some research topics were identified, including indications for LT for CRLM, oncological risk, antitumor regimens, graft loss, administration of anti-immunity drugs and solutions for graft deficiency. The main candidate selection criteria are good patient performance, good tumor biological behavior and chemosensitivity. Chemotherapy should be administered before transplantation but is not commonly administered posttransplantation for preventive purposes. Mammalian target of rapamycin regimens are recommended for their potential oncological benefit, although there are limited cases. In addition to extended criterion grafts, living donor grafts and small grafts combined with two-stage hepatectomy are efficient means to resolve organ deficiency. LT has been proven to be an effective treatment for selected patients with liver-only CRLM. Due to limited donor grafts, high cost and poorly clarified oncological risks, LT for unresectable CRLM should be strictly performed under a well-organized study plan in selected patients. Some vital factors, like LT indication and anti-tumor and anti-immune treatment, remain to be confirmed. Ongoing clinical trials are expected to delineate these topics.
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The coronavirus disease 2019 (COVID-19) comprises more than just severe acute respiratory syndrome. It also interacts with the cardiovascular, nervous, renal, and immune systems at multiple levels, increasing morbidity in patients with underlying cardiometabolic conditions and inducing myocardial injury or dysfunction. Transcutaneous auricular vagus nerve stimulation (taVNS), which is derived from auricular acupuncture, has become a popular therapy that is increasingly accessible to the general public in modern China. Here, we begin by outlining the historical background of taVNS, and then describe important links between dysfunction in proinflammatory cytokine release and related multiorgan damage in COVID-19. Furthermore, we emphasize the important relationships between proinflammatory cytokines and depressive symptoms. Finally, we discuss how taVNS improves immune function via the cholinergic anti-inflammatory pathway and modulates brain circuits via the hypothalamic-pituitary-adrenal axis, making taVNS an important treatment for depressive symptoms on post-COVID-19 sequelae. Our review suggests that the link between anti-inflammatory processes and brain circuits could be a potential target for treating COVID-19-related multiorgan damage, as well as depressive symptoms using taVNS.
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Music and instruction-guided relaxation (MIGR) is a complementary therapeutic tool used in the treatment of the major depressive disorder (MDD). However, the neural mechanism that underlies the effect of MIGR on MDD patients is not known. Twenty-three right-handed MDD patients and 23 age-, sex-, handedness-, and educational level-matched healthy controls were enrolled. Resting-state functional MRI data were acquired from patients before and after MIGR and from healthy controls. The relationships between insular subregion-based functional connectivity and Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale (HAM-A), Automatic Thoughts Questionnaire, and Ruminative Responses Scale scores were examined. One-way analysis of variance exhibited significant differences among the three groups in functional connectivity between the left dorsal anterior insula (dAI) and left superior medial frontal gyrus (SMFG), left dAI and left precuneus, left posterior insula and left gyrus rectus, right ventral anterior insula (vAI) and left posterior cingulate cortex (PCC), right vAI and right inferior frontal gyrus (R-IFG). Further comparisons in regions of interest showed that MDD patients before MIGR showed decreased functional connectivity between the left dAI and left SMFG, left dAI and left precuneus, left posterior insula, and left gyrus rectus, right vAI and left PCC, right vAI and R-IFG relative to those in healthy controls. The strength of functional connectivity between the right dAI and left putamen also exhibited a negative correlation with the HAM-A score in MDD cases before MIGR. MIGR may result in enhanced functional connectivity in insular subregions, thereby potentially increasing the regulatory influence of cognitive reappraisal.
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Corteza Cerebral/diagnóstico por imagen , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/terapia , Musicoterapia/métodos , Red Nerviosa/diagnóstico por imagen , Terapia por Relajación/métodos , Adulto , Trastorno Depresivo Mayor/psicología , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Terapia por Relajación/psicología , Resultado del TratamientoRESUMEN
Transcutaneous auricular vagus nerve stimulation (taVNS) is a relatively non-invasive alternative treatment for patients suffering from major depressive disorder (MDD). It has been postulated that acupuncture may achieve its treatment effects on MDD through suppression of vagal nerve inflammatory responses. Our previous research established that taVNS significantly increases amygdala-dorsolateral prefrontal cortex connectivity, which is associated with a reduction in depression severity. However, the relationship between taVNS and the central/peripheral functional state of the immune system, as well as changes in brain neural circuits, have not as yet been elucidated. In the present paper, we outline the anatomic foundation of taVNS and emphasize that it significantly modulates the activity and connectivity of a wide range of neural networks, including the default mode network, executive network, and networks involved in emotional and reward circuits. In addition, we present the inflammatory mechanism of MDD and describe how taVNS inhibits central and peripheral inflammation, which is possibly related to the effectiveness of taVNS in reducing depression severity. Our review suggests a link between the suppression of inflammation and changes in brain regions/circuits post taVNS.
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Encéfalo/fisiopatología , Trastorno Depresivo/terapia , Red Nerviosa/fisiopatología , Estimulación del Nervio Vago , Trastorno Depresivo/fisiopatología , HumanosRESUMEN
BACKGROUND & PURPOSE: Malignant middle cerebral artery infarctions (mMCAI) are one of the most devastating ischemic strokes, with up to 80% mortality in non-surgically treated patients. With the publication of three European randomized controlled trials (RCTs), decompressive hemicraniectomy (DHC) was recommended in patients with mMCAI who are aged ≤ 60 years. Recently, three other RCTs enrolling patients aged > 60 years were published; thus, it is necessary to update the previous meta-analysis to re-evaluate the effects of DHC in mMCAI. METHODS: A systematic literature search of PubMed, EMBASE, and the Cochrane Library was conducted for published RCTs investigating the effects of DHC in mMCAI. Primary outcomes were mortality and major disability (modified Rankin Scale score: 4-5) among survivors. Secondary outcomes were death or major disability (mRS score > 3), and death or severe disability (mRS score > 4). Effect sizes were expressed in Peto odds ratio (Peto OR) with 95% confidence intervals. RESULTS: Six studies with 314 patients were subjected to meta-analysis. Data showed that DHC, significantly decreased mortality risk, death or major disability (mRS score > 3), and death or severe disability (mRS score > 4); but was associated with a slightly higher proportion of major disability (mRS score: 4-5) among survivors. There were no statistically significant age differences. CONCLUSIONS: Compared to conservative treatment, DHC significantly decreased mortality and improved functional outcome, with a non-significant increase in the proportion of survivors with major disability. Further studies are required for multidimensional evaluation of DHC for mMCAI.
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Edema Encefálico/cirugía , Craneotomía/métodos , Infarto de la Arteria Cerebral Media/cirugía , Hipertensión Intracraneal/cirugía , Edema Encefálico/etiología , Descompresión Quirúrgica , Humanos , Infarto de la Arteria Cerebral Media/complicaciones , Infarto de la Arteria Cerebral Media/mortalidad , Hipertensión Intracraneal/etiología , Accidente Cerebrovascular/etiología , Resultado del TratamientoRESUMEN
OBJECTIVE: To compare the efficacy of dextraldexmede (DEX) and propofol on sedation and ß-endorphin (ß-EP) in patients with moderate and severe traumatic brain injury (TBI). METHODS: Ninety patients with moderate and severe TBI with Glasgow coma score (GCS) 6-13 were randomly divided into three groups according to the order of admission of odd and even numbers. In group A (DEX/+morphine), DEX load 0.5-1.0 µg/kg was injected within 30 minutes, and maintaining at 0.2-0.6 µg×kg⻹ × h⻹ for 24 hours; and in group B (propofol/+ morphine), propofol load 0.5-2.0 mg/kg was injected within 10 minutes, and maintaining at 1-3 mg×kg⻹×h⻹ for 72 hours. Patients with poor efficacy were added with morphine intravenously. In group C, intramuscular injection of pethidine and other temporary medication was injected. The comprehensive assessment was conducted according to the Riker sedation and agitation score, combined with the physiological body reaction positive indicator elimination. The vital signs was monitored, and blood white blood cell (WBC) count, blood sugar, cortisol and ß-EP before and after administration were determined. RESULTS: (1) The sedation efficiency rate of the group A, B, C were 84.38% (27/32), 80.64% (25/31), 77.78% (21/27), respectively. The booster dose of morphine in group A was less than that in group B (24 h dosage: 16.23 ± 3.45 mg vs. 21.34 ± 5.55 mg). (2) Blood pressure and heart rate were significantly affected in the group A. The mean arterial pressure (MAP) in 0.5 hour of reaching loading dose in group A was significantly lower than that in group B and C (75.50 ± 9.35 mm Hg vs. 87.90 ± 8.05 mm Hg, 85.70 ± 7.10 mm Hg, both P<0.05). (3) WBC and cortisol levels showed downwards trends after treatment in group A and group B; WBC fell more in the group A compared with group B, cortisol level fell more in group B compared with group A, and the WBC and cortisol level began to decline after 24 hours in group C. (4) There were no significant differences in blood sugar and ß-EP levels before and after treatment in group B, but ß-EP had an increasing tendency in group A and group C, and the amplification in group C was more obvious than that in group A. CONCLUSIONS: The sedation efficacy of DEX was superior to propofol in moderate and severe TBI, and was able to control excessive stress response after TBI better, and with more effect on blood pressure. Plasma ß-EP was elevated during the early phase of brain injury by DEX, which was considered as its positive role in the regulation of early stress.
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Lesiones Encefálicas/tratamiento farmacológico , Dexmedetomidina/uso terapéutico , Hipnóticos y Sedantes/uso terapéutico , betaendorfina/metabolismo , Adulto , Presión Sanguínea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Propofol/uso terapéuticoRESUMEN
The efficiency of neural circuits is modified by changes not only in synaptic strength, but also in intrinsic excitability of neurons. In CA1 hippocampal pyramidal neurons, bidirectional changes in the intrinsic excitability are often presented after induction of synaptic long-term potentiation or depression. This plasticity of intrinsic excitability has been identified as a cellular correlate of learning. Besides, behavioral learning often involves action of reinforcement or rewarding mediated by dopamine (DA). Here, we examined how DA influences the intrinsic plasticity of CA1 hippocampal pyramidal neurons when high-frequency stimulation (HFS) was applied to Schaffer collaterals. The results showed that DA inhibits the decrease in rheobase and increase in mean firing rate of pyramidal neurons induced by HFS, and that this inhibition was abolished by the D1-like receptor antagonist SCH23390 but not by the D2-like receptor antagonist sulpiride. The results suggest that DA inhibits the potentiation of excitability induced by presynaptic HFS, and that this inhibition depends on the activation of D1-like receptors.
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Potenciales de Acción/efectos de los fármacos , Región CA1 Hipocampal/efectos de los fármacos , Dopamina/farmacología , Potenciación a Largo Plazo/efectos de los fármacos , Células Piramidales/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Benzazepinas/farmacología , Región CA1 Hipocampal/fisiología , Antagonistas de Dopamina/farmacología , Estimulación Eléctrica , Potenciación a Largo Plazo/fisiología , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Células Piramidales/fisiología , Ratas , Ratas Sprague-Dawley , Sulpirida/farmacologíaRESUMEN
OBJECTIVE: To explore the relationship between contractile characteristics and fiber type conversion in hind-limb unloading mice soleus. METHODS: After 28-day hind-limb unloading and muscle atrophy, we used the method of isolated muscle perfusion with different stimulated protocols to determine the changes in contractile characteristics including the isometric twitch force and tetanus force and fatigue index of slow twitch muscle in mice. The muscle myofibrillar composition and fiber type conversion were detected by immunofluorescence staining and real-time PCR. RESULTS: The isometric twitch force and the tetanus force and fatigue index were decreased progressively in 28-day unloaded mice soleus, with the increase in fast twitch fiber subtype and the decrease in slow twitch fiber subtype. CONCLUSION: The alteration of contractile characteristics is relevant to the slow-to-fast fiber conversion in mice soleus after 28-day hind-limb unloading.
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Suspensión Trasera/fisiología , Contracción Muscular/fisiología , Animales , Ratones , Ratones Endogámicos C57BL , Fatiga Muscular/fisiología , Fibras Musculares de Contracción Rápida/fisiología , Fibras Musculares de Contracción Lenta/fisiología , Músculo Esquelético/patología , Músculo Esquelético/fisiología , Atrofia MuscularRESUMEN
The purpose of this study is to identify the electrical activity of neuron, the existence of the transition from bursting pattern to spiking pattern and the ion mechanism of the bursting pattern. The intracellular electrical activity patterns of single neurons in the stomatogastric ganglion (STG) of crayfish were recorded when the extracellular calcium concentration ([Ca(2+)](o)) or calcium-dependent potassium channel blocker tetraethylammonium concentration ([TEA](o)) were changed, using intracellular recording method. These single neurons were also functionally isolated from the ganglion by application of atropine and picrotoxin which could block the inhibitory acetylcholine synapses and glutamatergic synapses respectively. When [Ca(2+)](o) was decreased by increasing EGTA, the membrane potential of the neuron was increased, and the electrical activity patterns were changed from the resting state with lower potential value (resting state of polarization) to the bursting pattern firstly, and then to the spiking pattern, at last to the resting state with higher potential value (resting state of depolarization). When [TEA](o) was increased, the membrane potential of the neuron was increased, and the electrical activity pattern was changed from the resting state with lower potential value (resting state of polarization) to the bursting pattern firstly, and then to the spiking pattern. The duration of the burst of the bursting pattern was increased. When [Ca(2+)](o) was increased or [TEA](o) was decreased, an inverse procedure of the electrical activity pattern was exhibited. On one hand, the results indicate that a single neuron can generate various electrical activity patterns corresponding to different physiological conditions, and the regularity of the transitions between different electrical activity patterns. On the other hand, the results identify that the initiation and termination of the burst in bursting pattern are determined by calcium-activated potassium conductance, which is adjusted by intracellular calcium concentration influenced by inward calcium current. It may be the ionic mechanism of generation of the bursting pattern in a single neuron.
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Potenciales de Acción/fisiología , Astacoidea/fisiología , Calcio/metabolismo , Ganglios de Invertebrados/fisiología , Neuronas/fisiología , Animales , Canales de Calcio/metabolismo , Canales de Potasio Calcio-Activados/metabolismoRESUMEN
OBJECTIVE: To study the relationship between multiple injuries and acute respiratory dysfunction (ARD). METHODS: One hundred and ten patients with multiple injuries admitted during the last 6 years were retrospectively analyzed. With ARD as the dependent variable and other 11 factors as independent variables, all analysis was done statistically on computer to identify the complication of ARD as a risk factor. RESULTS: Multivariable and single argument analysis showed systemic inflammatory response syndrome (SIRS), pulmonary contusion, co-existing lung disease as chronic obstructive pulmonary disease (COPD) and pneumonia, moderate hemothorax and pneumothorax, duration of shock over 12 hours, age over 55 years, injury severity score(ISS)>24 were high risk factors. CONCLUSION: Patients with multiple injuries with high risk factors should be kept under closer observation in order to prevent ARD and multiple organ dysfunction syndromes (MODS).
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Traumatismo Múltiple/complicaciones , Trastornos Respiratorios/etiología , Adolescente , Adulto , Anciano , Niño , Preescolar , Cuidados Críticos , Femenino , Humanos , Lactante , Unidades de Cuidados Intensivos/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Insuficiencia Multiorgánica/etiología , Insuficiencia Multiorgánica/prevención & control , Análisis Multivariante , Trastornos Respiratorios/prevención & control , Estudios Retrospectivos , Factores de RiesgoRESUMEN
OBJECTIVE: To introduce the characteristics of the integer multiple rhythm of cultured cardiac myocytes and to explore the cause of its generation. METHOD: Spontaneous beating rhythms of cultured cardiac myocytes were observed with photometry system and stochastic Chay model was used to simulate the experimental results. RESULT: Integer multiple rhythm was observed in the experiment. This kind of rhythm is similar to phenomena of sinus arrest. The integer multiple rhythm similar to that of the experiments was simulated in stochastic Chay model, and was demonstrated to be induced by the mechanism of autonomous stochastic resonance. CONCLUSION: The integer multiple rhythm observed in the experiment might be generated via the effect of autonomous stochastic resonance.