Pyrolysis Characteristics and Kinetic Analysis of Sediment from the Dianchi Lake in China

Pyrolysis properties and kinetic analysis of lake sediment, as well as evolution characteristics of the gaseous products at 5°C/min, 10°C/min, and 20°C/min, were investigated by TG-FTIR. Comparison to the TG and DTG curves at different heating rates, the pyrolysis process at 10°C/min could describe the sediment pyrolysis characteristics better than at 5°C/min and 20°C/min; thus the process of sediment pyrolysis could be considered as four stages. From the kinetics analysis, the nth-order chemical reaction model was suitable to describe the sediment pyrolysis reaction well. The values of n were within 2.55–3.42 and activation energy E was ranged from 15.83 KJ/mol to 57.92 KJ/mol at different heating rates. The gaseous products of H2O, CO2, CO, CH4, and SO2 and several functional groups (C-H, C=O, and C-O) could be found from the IR spectrum. From the evolution characteristics with the temperature, there were two evolution peaks for CO2 and one peak for CH4 and SO2. However, the evolution of CO always increased. Besides, the evolution peak for CO2, CH4, and SO2 all shifted to the low temperature region with the decrease of heating rate. The results could provide theoretical basis for harmless treatment and resource utilization of lake sediment

Effect of inlet splitter on pressure fluctuations in a double-suction centrifugal pump

In order to investigate the effect of inlet splitter on pressure fluctuations in a double-suction centrifugal pump, three research schemes, including no splitter (scheme I), a splitter along the flow passage centerline (scheme II) and a splitter above the flow passage centerline in the suction (scheme III), were designed. The flow in the pump was simulated by commercial code FLUENT. The viscous Navier-Stokes equations were handled with an unsteady calculation and the sliding mesh technique was applied to take into account the impeller-volute interaction. Based on the simulation results, the hydraulic performance and pressure fluctuations were obtained and analyzed in detail. The hydraulic performance agrees well with the experimental results. The pressure fluctuations under three schemes are different. The maximum amplitude of the pressure fluctuations in scheme II is the minimum. For monitoring points near volute tongue, rotating frequency and its harmonies are dominant under three research schemes. The maximum amplitude of pressure fluctuations of three schemes are all at the blade passing frequency. In particular, the maximum pressure fluctuation amplitude of scheme II was less than that of scheme I and scheme III, which illustrated that it is effective to reduce the peak value of pressure fluctuations in double suction centrifugal pump by installing a splitter in the suction properly

Bitter Taste Receptor Agonist (Quinine) Induces Traction Force Reduction and Calcium Flux Increase in Airway Smooth Muscle Cells from Ovalbumin-Sensitized and Challenged Rats

Recently, bitter taste receptors (TAS2Rs) have been found in the lung, which can be stimulated with TAS2R agonist such as quinine to relax airway smooth muscle cells (ASMCs) via intracellular Ca2+ signaling generated from restricted phospholipase C activation. This provides a promising new therapy for asthma because enhanced contractility and impaired ability of relaxation of the ASMCs within the bronchial wall of asthmatic patients are thought to be ultimately responsible for airway constriction in asthma. However, further study is required for characterization of the effect of TAS2R agonist on the mechanical behaviors of ASMCs, in particular the traction force generation and associated mechanism in asthma model. Here, we sensitized Sprague Dawley rats with ovalbumin (OVA) for up to 12 weeks to simulate chronic asthma symptoms. Subsequently, we isolated ASMCs from these rats, and studied the traction force and intracellular Ca2+ signaling of the cells with/out treatment of quinine hydrochloride, a well-known TAS2R agonist. The results demonstrated that quinine hydrochloride relaxed the ASMC in a dose dependent manner. It also evoked dose-dependent increase of intracellular calcium ([Ca2+]i) in the ASMCs. Perhaps more importantly, the quinine-induced traction force reduction and Ca2+ flux increase were correlated. Taken together, our findings indicate that TAS2R agonists (e.g. quinine hydrochloride) could reduce the ability of ASMCs to generate traction force via activation of the intracellular calcium signaling, which may contribute as one of the mechanisms for TAS2R agonist-induced ASMC relaxation. This provides additional evidence to support TAS2R agonists as a new class of compounds with potential in treatment of chronic asthma

DNN-Based ADNMPC of an Industrial Pickling Cold-Rolled Titanium Process via Field Enhancement Heat Exchange

The dynamic neural network based adaptive direct nonlinear model predictive control is designed to control an industrial microwave heating pickling cold-rolled titanium process. The identifier of the direct adaptive nonlinear model identification and the controller of the adaptive nonlinear model predictive control are designed based on series-parallel dynamic neural network training by RLS algorithm with variable incremental factor, gain, and forgetting factor. These identifier and controller are used to constitute intelligent controller for adjusting the temperature of microwave heating acid. The correctness of the controller structure, the convergence, and feasibility of the control algorithms is tested by system simulation. For a given point tracking, model mismatch simulation results show that the controller can be implemented on the system to track and overcome the mismatch system model. The control model can be achieved to track on pickling solution concentration and temperature of a given reference and overcome the disturbance

Single-atom tailoring of platinum nanocatalysts for high-performance multifunctional electrocatalysis

Platinum-based nanocatalysts play a crucial role in various electrocatalytic systems that are important for renewable, clean energy conversion, storage and utilization. However, the scarcity and high cost of Pt seriously limit the practical application of these catalysts. Decorating Pt catalysts with other transition metals offers an effective pathway to tailor their catalytic properties, but often at the sacrifice of the electrochemical active surface area (ECSA). Here we report a single-atom tailoring strategy to boost the activity of Pt nanocatalysts with minimal loss in surface active sites. By starting with PtNi alloy nanowires and using a partial electrochemical dealloying approach, we create single-nickel-atom-modified Pt nanowires with an optimum combination of specific activity and ECSA for the hydrogen evolution, methanol oxidation and ethanol oxidation reactions. The single-atom tailoring approach offers an effective strategy to optimize the activity of surface Pt atoms and enhance the mass activity for diverse reactions, opening a general pathway to the design of highly efficient and durable precious metal-based catalysts

Single-atom tailoring of platinum nanocatalysts for high-performance multifunctional electrocatalysis

Platinum-based nanocatalysts play a crucial role in various electrocatalytic systems that are important for renewable, clean energy conversion, storage and utilization. However, the scarcity and high cost of Pt seriously limit the practical application of these catalysts. Decorating Pt catalysts with other transition metals offers an effective pathway to tailor their catalytic properties, but often at the sacrifice of the electrochemical active surface area (ECSA). Here we report a single-atom tailoring strategy to boost the activity of Pt nanocatalysts with minimal loss in surface active sites. By starting with PtNi alloy nanowires and using a partial electrochemical dealloying approach, we create single-nickel-atom-modified Pt nanowires with an optimum combination of specific activity and ECSA for the hydrogen evolution, methanol oxidation and ethanol oxidation reactions. The single-atom tailoring approach offers an effective strategy to optimize the activity of surface Pt atoms and enhance the mass activity for diverse reactions, opening a general pathway to the design of highly efficient and durable precious metal-based catalysts

SNX14 deficiency-induced defective axonal mitochondrial transport in Purkinje cells underlies cerebellar ataxia and can be reversed by valproate

共济失调是一类以运动协调性紊乱为主要特征的神经系统症状，临床表现包括步态不稳、丧失平衡、吞咽困难、眼球运动异常、肌张力受损等。厦门大学医学院神经科学研究所王鑫教授团队首次从轴突线粒体运输这一全新视角揭示了一类遗传性共济失调的发病机制，并发现抗癫痫药--丙戊酸大幅度减缓模型小鼠的疾病进程，具有较强的转化应用价值，有望为共济失调提供新的治疗手段。 该研究工作由王鑫教授指导完成，厦门大学医学院助理教授张洪峰和博士生洪育娟共同完成主要实验工作。Loss-of-function mutations in SNX14 cause autosomal recessive spinocerebellar ataxia 20, which is a form of early-onset cerebellar ataxia that lacks molecular mechanisms and mouse models. We generated Snx14-deficient mouse models and observed severe motor deficits and cell-autonomous Purkinje cell degeneration. SNX14 deficiency disrupted microtubule organization and mitochondrial transport in axons by destabilizing the microtubule-severing enzyme spastin, which is implicated in dominant hereditary spastic paraplegia with cerebellar ataxia, and compromised axonal integrity and mitochondrial function. Axonal transport disruption and mitochondrial dysfunction further led to degeneration of high-energy-demanding Purkinje cells, which resulted in the pathogenesis of cerebellar ataxia. The antiepileptic drug valproate ameliorated motor deficits and cerebellar degeneration in Snx14-deficient mice via the restoration of mitochondrial transport and function in Purkinje cells. Our study revealed an unprecedented role for SNX14-dependent axonal transport in cerebellar ataxia, demonstrated the convergence of SNX14 and spastin in mitochondrial dysfunction, and suggests valproate as a potential therapeutic agent.We thank Tim Huang for helpful discussion, Wei Mo for sharing mouse lines, Li Zhong for sharing reagents, Aidong Han, Luming Yao, Caiming Wu, Mingxia Zhu, Qingfeng Liu, Lin Zhu, Shuo Zhang, Haiping Zheng, and Changchuan Xie for technical assistance, and Cui Li for providing bioinformatics software. We also thank Novogene Co., Ltd. and PTM Biolab Co., Ltd. for technical assistance in the transcriptomic and proteomic analyses, respectively. 厦门大学医学院许华曦、赵颖俊、张云武、杜丹教授在研究过程中给予大力帮助和支持。本研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持

Space advanced technology demonstration satellite

The Space Advanced Technology demonstration satellite (SATech-01), a mission for low-cost space science and new technology experiments, organized by Chinese Academy of Sciences (CAS), was successfully launched into a Sun-synchronous orbit at an altitude of similar to 500 km on July 27, 2022, from the Jiuquan Satellite Launch Centre. Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit, SATech-01 is equipped with 16 experimental payloads, including the solar upper transition region imager (SUTRI), the lobster eye imager for astronomy (LEIA), the high energy burst searcher (HEBS), and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer (CPT). It also incorporates an imager with freeform optics, an integrated thermal imaging sensor, and a multi-functional integrated imager, etc. This paper provides an overview of SATech-01, including a technical description of the satellite and its scientific payloads, along with their on-orbit performance

Membrane échangeur de cation inorganique à BBB : focus sur le transport du lithium et les canaux TRPV dans les cellules endothéliales cérébrales humaines

Dans un premier temps, nous avons exploré l'effet du lithium sur l'expression des ARNs des transporteurs et des enzymes de métabolisation dans les cellules hCMEC / D3. Notre étude a montré que le traitement par chlorure de lithium (LiCl) à 10 mM augmente les ARNm de la claudin-3, du transporteur ABCG2, du CYP1A1 et de la glutathion-S-transférase GSTM3, tandis que d'autres marqueurs de la BHE n'ont pas été significativement modifiés. Par la suite, nous avons étudié les transporteurs de sodium dans l'influx de lithium dans les cellules endothéliales cérébrales. Cette étude a porté sur l'étude de certains transporteurs sodiques (NHE (SLC9), NBC (SLC4) et NKCC (SLC12)). L'expression génique des transporteurs de Na+ dans les cellules hCMEC / D3, les modèles BBB dérivés de cellules hématopoïétiques humaines (HBLEC) et les cellules endothéliales cérébrales humaines primaires (hPBMEC) ont montré l'ordre suivant concernant leur niveau d'expression: NHE1> NKCC1> NHE5> NBCn1 tandis que les ARNs NHE2, NHE3, NHE4, NBCn2, NBCe1 et NBCe2 ont été à peine détectés. L'absence de Na+ dans le milieu d'incubation a augmenté d'un facteur 3 l'influx de Li+ dans les cellules D3. Les inhibiteurs de transport sodiques de type DMA (inhibiteur NHE), DIDS (inhibiteur des transporteurs anioniques) et bumétanide (inhibiteur NKCC) ont diminué respectivement de façon significative l'influx de Li+ de 52%, 51% et 47% dans les cellules D3, tandis que le S0859 (inhibiteur NBC) l'augmentait significativement d'un facteur 2,3. Le zoniporide (inhibiteur de NHE1) et l'extinction de l'expression de NHE1 par siRNA n'ont eu aucun effet sur l'influx de Li+ par les cellules D3. Notre étude montre que les transporteurs NHE1 et / ou NHE5, NBCn1 et NKCC1 jouent un rôle significatif dans l'influx de Li + dans des cellules endothéliales cérébrales et suggère qu'ils peuvent être des biomarqueurs de la réponse des patients au lithium. L'expression fonctionnelle des canaux TRP de la sous-famille vanilloïdes (TRPV) et leur rôle dans la l'influx Ca2+ dans les cellules endothéliales des microvaisseaux cérébraux (BMEC) formant la barrière hémato-encéphalique (BBB) ont été mal étudiés. Par qRt-PCR, nos travaux ont montré des niveaux importants d'ARNs de TRPV2 dans la lignée D3 et dans des cultures primaires de cellules endothéliales cérébrales humaines issues de patients. L'expression protéique élevée de TRPV2 a été confirmée par Western blot et par immunofluorescence notamment au niveau de la membrane plasmique des cellules D3. L'augmentation du Ca2+ intracellulaire induite par TRPV2 a été montré par une stimulation thermique et bloquée par un inhibiteur non-spécifique des TRPVs, le rouge de ruthénium (RR) et par l'inhibiteur spécifique de TRPV2, le tranilast (TNL). Le cannabidiol (CBD), un agoniste TRPV2 de haute affinité, induit une augmentation durable de Ca2+ qui est aboli par le RR ou le TNL. Le CBD induit de manière dose-dépendante la prolifération des cellules D3 avec une CE50 de 0,3 ± 0,1 µM, et inhibée par le TNL ou l'extinction du TRPV2 par siRNA. La prolifération cellulaire a été significativement réduite de 31% dans les cellules dont l'expression en TRPV2 a été réduite en utilisant une stratégie efficace de siRNA. Un test de migration cellulaire (would healing) a montré que la migration cellulaire induite par le CBD était inhibée par le siRNA TRPV2 et le TNL. La tubulogenèse des cellules D3 dans le matrigel a également été significativement augmentée de 41% et de 73% après 7h ou 24h de traitement au CBD, et abolie par le TNL ou le siRNA TRPV2. Nos résultats démontrent que l'activation de TRPV2 induit la prolifération cellulaire et la migration, la tubulogenèse et TEER des cellules. Ces résultats suggèrent que le TRPV2 pourrait être une cible pharmacologique lorsque la BHE est altérée pour la réparer.First, we explored the effect of Lithium on mRNA expression of transporters and metabolizing enzymes in hCMEC/D3 cells. Our study showed that LiCl treatment for 6 days at a concentration of 10 mM induced transcription of the TJ protein claudin-3, the ABC transporter BCRP/ABCG2, the cytochrome p-450 CYP1A1 and the glutathione-S-transferase GSTM3, whereas the other selected markers were not significantly affected. Our findings provide new insights into the effects of lithium on some drug transporters and drug-metabolizing enzymes in the BBB that may have consequences in pharmacotherapy. Second, we found that sodium transporters are involved in lithium influx in brain endothelial cells. This study deciphers Li+ transport at the BBB focusing on Na+-coupled transporters (NHE (SLC9), NBC (SLC4) and NKCC (SLC12)). The BBB permeability of Li+ evaluated in the rat was 2% that of high passive diffusion compounds. Gene expression of Na+-coupled transporters in hCMEC/D3 cells, human hematopoetic stem cells-derived BBB models (HBLEC) and human primary brain microvascular endothelial cells (hPBMEC) showed the following rank order with close expression profile: NHE1 > NKCC1 > NHE5 > NBCn1 while NHE2, NHE3, NHE4, NBCn2, NBCe1 and NBCe2 mRNA were barely detected. Na+ depletion increased Li+ uptake by 3.3-fold in hCMEC/D3 and Li+ permeability through HBLECs monolayers by 1.6-fold. DMA (NHE inhibitor), DIDS (anionic carriers inhibitor) and bumetanide (NKCC inhibitor) decreased significantly the uptake of Li+ by hCMEC/D3 by 52%, 51% and 47%, respectively while S0859 (NBC inhibitor) increased significantly the uptake of Li+ by 2.3-fold. Zoniporide (NHE1 inhibitor) and siRNA interference against NHE1 had no effect on Li+ uptake by hCMEC/D3 cells. Li+ permeability through HBLEC was significantly increased by DIDS, bumetanide, S0859 and zoniporide. Our study suggests that NHE1 and/or NHE5, NBCn1, and NKCC1 may play a significant role in the Li+ transport across the human BBB and be putative variability factors of Li+ response. Third, we found that cannabidiol increases proliferation, migration and tubulogenesis of hCMEC/D3 human cerebral microvessel endothelial cells through TRPV2 activation. The functional expression of transient receptor potential vanilloid channels (TRPV) and their role in Ca2+ dynamics in brain microvessel endothelial cells (BMEC) forming the blood-brain barrier (BBB) have been poorly investigated. Using q-RTPCR abundant TRPV2 mRNA levels in the human BBB cell line hCMEC/D3 and in primary cultures of BMEC from patient brain biopsies were found. High protein expression of TRPV2 was confirmed by western blotting and immunofluorescence in the plasma membrane and intracellular compartments of hCMEC/D3 cells. TRPV2-mediated increase in intracellular Ca2+ was triggered by heat stimulation and blocked by the wide TRPVs inhibitor ruthenium red (RR) and the TRPV2 inhibitor tranilast (TNL). Cannabidiol (CBD), a high-affinity TRPV2 agonist, induced a long-lasting increase in intracellular Ca2+ abolished by RR or TNL. CBD dose-dependently induced hCMEC/D3 cell proliferation with an EC50 of 0.3±0.1 µM, and inhibited by TNL or silencing TRPV2. Cell proliferation was significantly reduced by 31% in cells silenced for TRPV2 using efficient siRNA strategy. Wound healing assay showed that CBD-induced cell migration which was inhibited by TNL or TRPV2 siRNA. The tubulogenesis of hCMEC/D3 cells in matrigel was also significantly increased by 41% and 73% after 7h or 24h CBD treatment, respectively, and abolished by TNL or TRPV2 siRNA. Finally, CBD increased the transendothelial electrical resistance (TEER) of monolayers of primary human endothelial cells cultured in transwell experiments. Our results demonstrate that activation of TRPV2 induces cell proliferation and migration, tubulogenesis and TEER of human BBB endothelial cells and could be a new target for modulating the BBB

Blood–Brain Barrier Modulation to Improve Glioma Drug Delivery

The blood–brain barrier (BBB) is formed by brain microvascular endothelial cells that are sealed by tight junctions, making it a significant obstacle for most brain therapeutics. The poor BBB penetration of newly developed therapeutics has therefore played a major role in limiting their clinical success. A particularly challenging therapeutic target is glioma, which is the most frequently occurring malignant brain tumor. Thus, to enhance therapeutic uptake in tumors, researchers have been developing strategies to modulate BBB permeability. However, most conventional BBB opening strategies are difficult to apply in the clinical setting due to their broad, non-specific modulation of the BBB, which can result in damage to normal brain tissue. In this review, we have summarized strategies that could potentially be used to selectively and efficiently modulate the tumor BBB for more effective glioma treatment