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The highly variable response rates to immunotherapies underscore our limited knowledge about how tumors can manipulate immune cells. Here the membrane topology of natural killer (NK) cells from patients with liver cancer showed that intratumoral NK cells have fewer membrane protrusions compared with liver NK cells outside tumors and with peripheral NK cells. Dysregulation of these protrusions prevented intratumoral NK cells from recognizing tumor cells, from forming lytic immunological synapses and from killing tumor cells. The membranes of intratumoral NK cells have altered sphingomyelin (SM) content and dysregulated serine metabolism in tumors contributed to the decrease in SM levels of intratumoral NK cells. Inhibition of SM biosynthesis in peripheral NK cells phenocopied the disrupted membrane topology and cytotoxicity of the intratumoral NK cells. Targeting sphingomyelinase confers powerful antitumor efficacy, both as a monotherapy and as a combination therapy with checkpoint blockade.
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Células Asesinas Naturales , Neoplasias Hepáticas , Humanos , Sinapsis Inmunológicas , Citotoxicidad InmunológicaRESUMEN
Septins are a family of filament-forming GTP-binding proteins that regulate fundamental cellular activities, such as cytokinesis and cell polarity. In general, septin filaments function as barriers and scaffolds on the cell cortex. However, little is known about the mechanism that governs the recruitment and localization of the septin complex to the cell cortex. Here, we identified the Cdc42 GTPase-activating protein Rga6 as a key protein involved in promoting the localization of the septin complex to the cell cortex in the fission yeast Schizosaccharomyces pombe. Rga6 interacts with the septin complex and partially colocalizes with the septin complex on the cell cortex. Live-cell microscopy analysis further showed septin enrichment at the cortical regions adjacent to the growing cell tip. The septin enrichment likely plays a crucial role in confining active Cdc42 to the growing cell tip. Hence, our findings support a model whereby Rga6 regulates polarized cell growth partly through promoting targeted localization of the septin complex on the cell cortex. This article has an associated First Person interview with the first author of the paper.
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Proteínas Activadoras de GTPasa , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Septinas , Citocinesis/genética , Proteínas Activadoras de GTPasa/genética , Proteínas Activadoras de GTPasa/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Septinas/genética , Septinas/metabolismoRESUMEN
Entomopathogenic fungi, including Metarhizium species, represent promising environmentally friendly biopesticides. Understanding the molecular mechanisms governing their infection processes is vital for enhancing their effectiveness. Transcription factors (TFs) play critical roles in gene regulation, yet the functions of many TFs in M. robertsii remain unknown. Homeobox transcription factors, implicated in diverse cellular processes, have received limited attention in entomopathogenic fungi. Here, we identify and characterize, a homeobox TF, MrHOX7, in the model entomopathogenic fungus M. robertsii. Subcellular localization and transcriptional profiling revealed MrHOX7's nuclear localization and high expression during conidia and appressoria formation. Deletion of Mrhox7 (ΔMrhox7) enhanced conidial tolerance to heat and UV-B stress, accompanying with upregulated stress-related gene expression. Intriguingly, ΔMrhox7 exhibits inhibited virulence exclusively through topical inoculation. Further investigations unveiled reduced conidial adhesion and appressorium formation, with downregulation of the adhesion gene Mad1 and appressorium-related genes, as the underlying causes of the reduced fungal virulence. Our findings illuminate the role of MrHOX7 in stress tolerance and virulence, providing insights into the molecular basis of fungal biopesticides.
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Metarhizium , Factores de Transcripción , Animales , Virulencia/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Genes Homeobox , Agentes de Control Biológico , Regulación Fúngica de la Expresión Génica , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Esporas Fúngicas/genéticaRESUMEN
The aqueous alkaline rechargeable batteries (AARBs) have an attractive potential for electrochemical energy storage devices. In view of the advantages of high theoretical capacity and desirable negative operating window, bismuth (Bi) has been deemed as a hopeful anode material for AARBs. Unfortunately, intensive reported works of Bi anode are still confronted with limited capacity and poor cycling stability. Herein, the designed electrodes of different size Bi nanoparticles embedded in porous carbon nanofibers with a contrasting nitrogen doping content are obtained by electrospinning and thermal treatment processes. The effect of the N dopant in carbon shell is demonstrated on the Bi core, which is in favor of enhancing the capacity of Bi anodes. More importantly, the core structure with highly dispersed ultrasmall Bi nanoparticles (<20 nm) in carbon matrix plays a crucial role in long-term durability. Accordingly, the optimized polydisperse ultrasmall Bi nanoparticles confined in N-rich porous carbon nanofibers electrode (Bi@NPCF) presents an admirable capacity of 196.1 mAh g-1 at 3 A g-1 and outstanding durable lifespan (retain 116.95% after 10 000 cycles). In addition, the fabricated Bi@NPCF//NiCo2 O4 battery exhibits an exceptional energy and power density with durable stability (95.9% after 5000 cycles).
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The gaseous hormone ethylene participates in many physiological processes in plants. Ethylene-inhibited root elongation involves PIN-FORMED2 (PIN2)-mediated basipetal auxin transport, but the molecular mechanisms underlying the regulation of PIN2 function by ethylene (and therefore auxin distribution) are poorly understood. Here, we report that the plant-specific and ethylene-responsive HD-Zip gene HB52 is involved in ethylene-mediated inhibition of primary root elongation in Arabidopsis thaliana Biochemical and genetic analyses demonstrated that HB52 is ethylene responsive and acts downstream of ETHYLENE-INSENSITIVE3 (EIN3). HB52 knockdown mutants displayed an ethylene-insensitive phenotype during primary root elongation, while its overexpression resulted in short roots, as observed in ethylene-treated plants. In addition, root auxin distribution and gravitropism were impaired in HB52 knockdown and overexpression lines. Consistent with these findings, in vitro and in vivo binding experiments showed that HB52 regulates the expression of auxin transport-related genes, including PIN2, WAVY ROOT GROWTH1 (WAG1), and WAG2 by physically binding to their promoter regions. These findings suggest that HB52 functions in the ethylene-mediated inhibition of root elongation by modulating the expression of auxin transport components downstream of EIN3, revealing a mechanism in which HB52 acts as an important node in the crosstalk between ethylene and auxin signaling during plant growth and development.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Ácidos Indolacéticos/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiología , Regulación de la Expresión Génica de las Plantas , Gravitropismo/genética , Gravitropismo/fisiología , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiologíaRESUMEN
PURPOSE: The COVID-19 pandemic has led to the cancellation or deferment of many elective cancer surgeries. We performed a systematic review on the oncological effects of delayed surgery for patients with localised or metastatic renal cell carcinoma (RCC) in the targeted therapy (TT) era. METHOD: The protocol of this review is registered on PROSPERO(CRD42020190882). A comprehensive literature search was performed on Medline, Embase and Cochrane CENTRAL using MeSH terms and keywords for randomised controlled trials and observational studies on the topic. Risks of biases were assessed using the Cochrane RoB tool and the Newcastle-Ottawa Scale. For localised RCC, immediate surgery [including partial nephrectomy (PN) and radical nephrectomy (RN)] and delayed surgery [including active surveillance (AS) and delayed intervention (DI)] were compared. For metastatic RCC, upfront versus deferred cytoreductive nephrectomy (CN) were compared. RESULTS: Eleven studies were included for quantitative analysis. Delayed surgery was significantly associated with worse cancer-specific survival (HR 1.67, 95% CI 1.23-2.27, p < 0.01) in T1a RCC, but no significant difference was noted for overall survival. For localised ≥ T1b RCC, there were insufficient data for meta-analysis and the results from the individual reports were contradictory. For metastatic RCC, upfront TT followed by deferred CN was associated with better overall survival when compared to upfront CN followed by deferred TT (HR 0.61, 95% CI 0.43-0.86, p < 0.001). CONCLUSION: Noting potential selection bias, there is insufficient evidence to support the notion that delayed surgery is safe in localised RCC. For metastatic RCC, upfront TT followed by deferred CN should be considered.
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COVID-19/prevención & control , Carcinoma de Células Renales/mortalidad , Carcinoma de Células Renales/cirugía , Neoplasias Renales/mortalidad , Neoplasias Renales/cirugía , Tiempo de Tratamiento , COVID-19/epidemiología , COVID-19/transmisión , Carcinoma de Células Renales/patología , Control de Enfermedades Transmisibles , Humanos , Neoplasias Renales/patología , Nefrectomía , Tasa de SupervivenciaRESUMEN
Although dynamins and dynamin-related proteins (DRPs), a large GTPase superfamily, are involved in the budding of transport vesicles and division of organelles in eukaryotic cells, the function of these proteins in entomopathogenic fungi has not been reported to date. Here, DNM1, a DRP in Metarhizium robertsii, was characterized using gene disruption and complementation strategies. Mutant phenotype assays showed that the ΔDnm1 strain displayed increased defects in radial growth (â¼24%) and conidial production (â¼42%) compared to those of the wild type (WT), and reduced conidiation levels were accompanied by the repression of several key conidiation-related genes, including flbA, wetA, and flbD Additionally, mutant bioassays revealed that disruption of Dnm1 impaired the virulence (both topical inoculation and injection) of M. robertsii in the insect Galleria mellonella Further analysis demonstrated that deleting Dnm1 in fungi suppressed the transcriptional levels of several virulence genes in the insect hemocoel. Moreover, we found that DNM1 colocalized with peroxisomes and mitochondria. Importantly, disruption of Dnm1 abolished normal fungal endocytosis, resulting in significantly decreased numbers of, as well as morphological changes in, peroxisomes. These findings indicate that deletion of Dnm1 causes significant changes in the vegetative growth, sporulation, and virulence of M. robertsii due to changes in cell function and peroxisomes.IMPORTANCEDnm1 was found to be involved in fungal development and virulence, mediated peroxisomal fission, and normal endocytosis. This finding provides new insights into the cellular processes and pathogenicity in entomopathogenic fungi.
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Dinaminas/genética , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Metarhizium/fisiología , Animales , Dinaminas/metabolismo , Endocitosis/fisiología , Proteínas Fúngicas/metabolismo , Metarhizium/genética , Metarhizium/crecimiento & desarrollo , Metarhizium/patogenicidad , Mariposas Nocturnas/microbiología , Peroxisomas/fisiología , Control Biológico de Vectores , Esporas Fúngicas/crecimiento & desarrollo , VirulenciaRESUMEN
PURPOSE: To compare the staining intensity of the upper urinary tract (UUT) urothelium among three UUT delivery methods in an in vivo porcine model. MATERIALS AND METHODS: A fluorescent dye solution (indigo carmine) was delivered to the UUT via three different methods: antegrade perfusion, vesico-ureteral reflux via indwelling ureteric stent and retrograde perfusion via a 5F open-ended ureteral catheter. Twelve renal units were tested with 4 in each method. After a 2-hour delivery time, the renal-ureter units were harvested en bloc. Time from harvesting to analysis was also standardised to be 2 hours in each arm. Three urothelium samples of the same weight and size were taken from each of the 6 pre-defined points (upper pole, mid pole, lower pole, renal pelvis, mid ureter and distal ureter) and the amount of fluorescence was measured with a spectrometer. RESULTS: The mean fluorescence detected at all 6 predefined points of the UUT urothelium was the highest for the retrograde method. This was statistically significant with p-value less than <0.05 at all 6 points. CONCLUSIONS: Retrograde infusion of UUT by an open ended ureteral catheter resulted in highest mean fluorescence detected at all 6 pre-defined points of the UUT urothelium compared to antegrade infusion and vesico-ureteral reflux via indwelling ureteric stents indicating retrograde method ideal for topical therapy throughout the UUT urothelium. More clinical studies are needed to demonstrate if retrograde method could lead to better clinical outcomes compared to the other two methods.
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Administración Intravesical , Colorantes/administración & dosificación , Carmin de Índigo/administración & dosificación , Urotelio , Animales , Femenino , Modelos Animales , Porcinos , Cateterismo UrinarioRESUMEN
The versatile Mn3[Co(CN)6]2@SiO2@Ag core-shell NCs are prepared by a simple coprecipitation method. Ag nanoparticles with an average diameter of 12 nm deposited on the surface of Mn3[Co(CN)6]2@SiO2 through S-Ag bonding are fabricated in ethanol solution by reducing silver nitrate (AgNO3 ) with NaBH4 . The NCs possess T1 -T2 dual-modal magnetic resonance imaging ability. The inner Prussian blue analogs (PBAs) Mn3[Co(CN)6]2 exhibit bright two-photon fluorescence (TPF) imaging when excited at 730 nm. Moreover, the TPF imaging intensity displays 1.85-fold enhancement after loading of Ag nanoparticles. Besides, the sample also has multicolor fluorescence imaging ability under 403, 488, and 543 nm single photon excitation. The as-synthesized Mn3[Co(CN)6]2@SiO2@Ag NCs show a DOX loading capacity of 600 mg g(-1) and exhibit an excellent ability of near-infrared (NIR)-responsive drug release and photothermal therapy (PTT) which is induced from the relative high absorbance in NIR region. The combined chemotherapy and PTT against cancer cells in vitro test shows high therapeutic efficiency. The multimodal treatment and imaging could lead to this material a potential multifunctional system for biomedical diagnosis and therapy.
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Antineoplásicos/uso terapéutico , Cobalto/química , Cianuros/química , Hipertermia Inducida , Imagen por Resonancia Magnética/métodos , Manganeso/química , Nanopartículas del Metal/química , Imagen Óptica/métodos , Fotones , Fototerapia , Dióxido de Silicio/química , Animales , Antineoplásicos/farmacología , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Doxorrubicina , Liberación de Fármacos , Femenino , Humanos , Nanopartículas del Metal/ultraestructura , Ratones Desnudos , Imagen Multimodal , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , TemperaturaRESUMEN
Radical orchidectomy has been the standard surgery for testicular tumours. While a straightforward routine surgery, there are several finer points in the surgical technique and perioperative care that urologists should be familiar with. This mini-review discusses modifications to the conventional surgical approach such as organ-sparing surgery and the subinguinal approach, and practice points regarding prostheses and sperm banking that are pertinent to early management of a patient with a testicular tumour. PATIENT SUMMARY: We reviewed the evidence for surgical removal of a testicle for testicular cancer. There are a number of different techniques to minimise the extent of surgery. Surgeons should also discuss sperm banking and options for a testicular prosthesis with their patients.
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Orquiectomía , Neoplasias Testiculares , Humanos , Masculino , Neoplasias Testiculares/cirugía , Orquiectomía/métodos , Tratamientos Conservadores del Órgano/métodos , Testículo/cirugíaRESUMEN
This study aimed to investigate the roles of lysosome-related genes in BC prognosis and immunity. Transcriptome data from TCGA and MSigDB, along with lysosome-related gene sets, underwent NMF cluster analysis, resulting in two subtypes. Using lasso regression and univariate/multivariate Cox regression analysis, an 11-gene signature was successfully identified and verified. High- and low-risk populations were dominated by HR+ sample types. There were differences in pathway enrichment, immune cell infiltration, and immune scores. Sensitive drugs targeting model genes were screened using GDSC and CCLE. This study constructed a reliable prognostic model with lysosome-related genes, providing valuable insights for BC clinical immunotherapy.
Lysosome-related genes can be used to predict survival outcomes in BRCA patients.Significant differences were showed in the immune status of patient with different prognoses.Immunotherapy may show better therapeutic results in low-risk patients.The most promising targeted drugs in the low-risk group are mainly Lapatinib, Palbociclib and Ribociclib.
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Sensitivity and linearity are two crucial indices to assess the sensing capability of pressure sensors; unfortunately, the two mutually exclusive parameters usually result in limited applications. Although a series of microengineering strategies including micropatterned, multilayered, and porous approach have been provided in detail, the conflict between the two parameters still continues. Here, we present an efficient strategy to resolve this contradiction via modulus difference-induced embedding deformation. Both the microscopic observation and finite element simulation results confirm the embedding deformation behavior ascribed to the elastic modulus difference between soft electrode and rigid microstructures. The iontronic pressure sensor with high sensitivity (35 kPa-1) and wide linear response range (0-250 kPa) is further fabricated and demonstrates the potential applications in monitoring of high-fidelity pulse waveforms and human motion. This work provides an alternative strategy to guide targeted design of all-around and comprehensive pressure sensor.
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E-cadherin is an essential cellâcell adhesion protein that mediates canonical cadherin-catenin complex formation in epithelial lateral membranes. Ankyrin-G (AnkG), a scaffold protein linking membrane proteins to the spectrin-based cytoskeleton, coordinates with E-cadherin to maintain epithelial cell polarity. However, the molecular mechanisms governing this complex formation and its relationships with the cadherin-catenin complex remain elusive. Here, we report that AnkG employs a promiscuous manner to encapsulate three discrete sites of E-cadherin by the same region, a dynamic mechanism that is distinct from the canonical 1:1 molar ratio previously described for other AnkG or E-cadherin-mediated complexes. Moreover, we demonstrate that AnkG-binding-deficient E-cadherin exhibited defective accumulation at the lateral membranes and show that disruption of interactions resulted in cell polarity malfunction. Finally, we demonstrate that E-cadherin is capable of simultaneously anchoring to AnkG and ß-catenin, providing mechanistic insights into the functional orchestration of the ankyrin-spectrin complex with the cadherin-catenin complex. Collectively, our results show that complex formation between E-cadherin and AnkG is dynamic, which enables the maintenance of epithelial cell polarity by ensuring faithful targeting of the adhesion molecule-scaffold protein complex, thus providing molecular mechanisms for essential E-cadherin-mediated complex assembly at cellâcell junctions.
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Ancirinas , Polaridad Celular , Ancirinas/metabolismo , Cadherinas/metabolismo , Adhesión Celular , Células Epiteliales/metabolismo , Espectrina/metabolismo , HumanosRESUMEN
Here, we propose a fast and sensitive coulometric signal transduction method for ion-selective electrodes (ISEs) by utilizing a two-compartment cell. A potassium ion-selective electrode (K+-ISE) was connected as reference electrode (RE) and placed in the sample compartment. A glassy carbon (GC) electrode coated with poly(3,4-ethylenedioxythiophene) (GC/PEDOT), or reduced graphene oxide (GC/RGO), was connected as working electrode (WE) and placed in the detection compartment together with a counter electrode (CE). The two compartments were connected with an Ag/AgCl wire. The measured cumulated charge was amplified by increasing the capacitance of the WE. The observed slope of the cumulated charge with respect to the change of the logarithm of the K+ ion activity was linearly proportional to the capacitance of the GC/PEDOT and GC/RGO, estimated from impedance spectra. Furthermore, the sensitivity of the coulometric signal transduction using a commercial K+-ISE with internal filling solution as RE and GC/RGO as WE allowed to decrease the response time while still being able to detect a 0.2% change in K+ concentration. The coulometric method utilizing a two-compartment cell was found to be feasible for the determination of K+ concentrations in serum. The advantage of this two-compartment approach, compared to the coulometric transduction described earlier, was that no current passed through the K+-ISE that was connected as RE. Therefore, current-induced polarization of the K+-ISE was avoided. Furthermore, since the GCE/PEDOT and GCE/RGO (used as WE) had a low impedance, the response time of the coulometric response decreased from minutes to seconds.
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Here, we developed a wearable electrochemical sensor for pH and K+ monitoring in sweat. The sensor was composed of flexible reference electrode, pH response electrode and K+ selective electrode, which were prepared through printing ß-CD functionalized graphene (ß-CD/RGO) water suspension on conductive PET substrate with microelectronic printer. ß-CD/RGO not only served as the pH sensitive material for pH response electrode with good sensitivity, selectivity and reproducibility due to its abundant oxygen-containing functional groups, but also worked as the ion-to-electron transducer for K+ selective electrode with good sensitivity. The wearable sensor exhibited good potential stability at different bending states. On-body sweat pH and K+ measurements showed high accuracy compared with ex-situ analysis.
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Técnicas Biosensibles , Grafito , Dispositivos Electrónicos Vestibles , Técnicas Electroquímicas , Concentración de Iones de Hidrógeno , Iones , Potasio , Reproducibilidad de los Resultados , SudorRESUMEN
Heterotrimeric G-proteins are crucial for fungal growth and differentiation. The α subunits of heterotrimeric G-proteins play an essential role in controlling signal transduction. However, the function of G-protein α subunits in entomopathogenic fungi remains poorly understood. Two group II Gα subunits (MrGPA2 and MrGPA4) were characterized in the entomopathogenic fungus, Metarhizium robertsii. Bioinformatics analysis showed that the relationship between MrGPA2 and MrGPA4 was closer than that of other MrGPAs. Both green fluorescent protein (GFP)-tagged MrGPA2 and MrGPA4 were localized at the cytoplasm. Furthermore, ∆MrGpa2∆MrGpa4 double mutants showed remarkably reduced vegetative growth compared to the wild-type and single-mutant strains, which was accompanied by the downregulation of several growth-related genes, such as ssk2, pbs2, stuA, hog1, and ac. Only the ∆MrGpa2∆MrGpa4 double mutant was sensitive to Congo red stress. The insect bioassay demonstrated significantly attenuated virulence for the ∆MrGpa2∆MrGpa4 double mutant compared to the wild-type and single-mutant strains. Further analysis indicated that double deletion of MrGpa2 and MrGpa4 had no effect on appressorium formation but suppressed the expression levels of several virulence-related genes in the insect hemocoel. These findings demonstrate that MrGpa2 and MrGpa4 exhibit functional redundancy and contribute to the vegetative growth, stress tolerance, and pest control potential in M. robertsii.
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OBJECTIVE: To observe the effect of acupuncture on endoplasmic reticulum calcium, apoptosis number and Caspase-12 protein expression in hippocampal neurons of convulsive rats, so as to explore its mechanisms underlying improvement of convulsion. METHODS: SD rats were randomly divided into normal control, model and acupuncture groups, with 36 rats in each group. Rats in the normal control group received intraperitoneal injection (i.p.) of normal saline (2 mL), and those of the other 2 groups received i.p. of pentylenetetrazole (50 mg/kg) for establishing convulsion model. Manual acupuncture stimulation was applied to "Baihui"(GV20) and "Dazhui"(GV14) for 30 min after modeling. The hippocampal tissues were taken at 2, 12 and 48 h after modeling. The endoplasmic reticulum Ca2+ concentration (optical density, OD) was detected by using fluorescence probe technique and laser confocal microscopy, and the number of apoptosis of hippocampal neurons at the 3 time points detected by using terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) stain. The expression of Caspase-12 protein in hippocampus at 3 time points was observed by immunohistochemistry. RESULTS: In comparison with the normal group, the number of apoptotic cells of hippocampal neurons and the expression levels of Caspase-12 protein in hippocampus at 2, 12 and 48 h after seizures were obviously increased (P<0.01), and the OD value of Ca2+ at 3 time points significantly decreased (P<0.01) in the model group.Following acupuncture intervention, the increased levels of the number of apoptotic cells of hippocampal neurons and the expression of Caspase-12 protein in hippocampus at 3 time points and the decreased levels of OD value of Ca2+ at 3 time points were reversed in the acupuncture group (P<0.05, P<0.01). CONCLUSION: Acupuncture intervention is effective in reducing the apoptosis of hippocampal neurons in convulsion rats, which may be related to its functions in down-regulating Caspase-12 expression and promoting influx of Ca2+ in the hippocampal neurons.
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Terapia por Acupuntura , Lesiones Encefálicas , Calcio/metabolismo , Animales , Caspasa 12 , Retículo Endoplásmico , Hipocampo , Neuronas , Ratas , Ratas Sprague-Dawley , ConvulsionesRESUMEN
Developing efficient and recyclable membranes for water contaminant removal still remains a challenge in terms of practical applications. Herein, a recyclable membrane constituted of polyacrylonitrile-graphene and oxide-polydopamine was fabricated and demonstrated efficient adsorption capacities with respect to heavy metal ions (62.9 mg g-1 of Cu2+ ion, CuSO4 50 mg L-1) and organic dye molecules (306.7 mg g-1 of methylene blue and 339.6 mg g-1 of eriochrome black T, MB/EBT 50 mg L-1). The polyacrylonitrile fibers provide the skeleton of the membrane, while the graphene oxide and polydopamine endow the membrane with hydrophilicity, which is favorable for the adsorption of pollutants in water. Benefitting from the protonation and deprotonation effects of graphene oxide and polydopamine, the obtained membrane demonstrated promotion of the selective adsorption or desorption of pollutant molecules. This guarantees that the adsorbed pollutant molecules can be desorbed promptly from the membrane through simple pH adjustment, ensuring the reusability of the membrane. After ten adsorption-desorption cycles, the membrane could still maintain a desirable adsorption capacity. In addition, compared with other, similar membranes reported, this composite membrane displays the highest mechanical stability. This work puts forward an alternative strategy for recyclable membrane design and expects to promote the utilization of membrane techniques in practical wastewater treatment.
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Detection of heavy metal ions (HMIs) in water is an important topic in the field of analytical chemistry and environmental science. Fluorescence spectroscopy is one of the most promising strategies due to its simple instrument, low investment, rapid and convenient operation. However, current fluorescence probes for detecting HMIs are typically selective for certain ions. Herein we reported the development of a novel strategy that determined the total content of HMIs in water by fluorescence spectroscopy. A novel fluorescent nitrogen, sulfur co-doped carbon quantum dots (N, S-CQDs) was prepared via graphene oxide-assisted synthesis method. The results showed that, with the fluorescence quenching strategy, N, S-CQDs exhibited a wide linear response to a series of water-soluble metal ions. The fluorescence of N, S-CQDs is stable in a wide range of pH 4-11. The detection mechanism was proved that the integration, caused by coordination interaction between S element in N, S-CQDs and the d-orbital of associated metal ions, was the main reason for fluorescence quenching. In practice, the N, S-CQDs were applied to determine total content of HMIs in water successfully. Interestingly, further experiment proved that the N, S-CQDs could effectively remove HMIs in water after centrifuging and filtering thoroughly. It was shown that the fluorescence of N, S-CQDs was obviously quenched by the multiple-ions-involved water and scavenging effect of N, S-CQDs on HMIs with centrifugal in which the concentration of individuals meets the Chinese National Standard. This indicates that the N, S-CQDs are of a wide application prospect in water quality analysis.