Rapid Hydrothermal Synthesis of Submillimeter Ultralong Flexible Hydroxyapatite Fiber Using Different pH Regulators

Hydroxyapatite fiber （HAF） was fabricated via a one-step hydrothermal route by using urea （CA）, acetamide （AA） and propanamide （PA） as pH regulators, respectively, and the reaction time was only 0.5 h. The HAF synthesized by CA as the pH regulator was agglomerated with irregular morphology, while using AA or PA as the pH regulator, the HAF was composed of well-dispersed fibers with lengths larger than 200 pm. Two different morphologies form mainly due to the different hydrolysis rates of the pH regulators. Most of the fibers synthesized by the three pH regulators showed curving appearance, implying their outstanding flexibility. The technique in this paper allows the rapid formation of flexible HAF and may have wider applications in the restorations and reinforcement composites.

The pH control optimization in the crop fertigation system using ANN

pH regulation is a complicated and comprehensive technique in the crop fertigation system. In this paper, a method is put forward to improve the quality of pH regulation, using artificial neural network to map a nonlinear relationship between pH interfering factor and the switching frequency of pH control valve, which achieves the dynamic feedforward compensation to the main control system.

Land Management Effects on Biogeochemical Functioning of Salt-Affected Paddy Soils

Most lowlands in Northeast Thailand(Isaan region)are cultivated with rice and large areas are affected by salinity, which drastically limits rice production.A field experiment was conducted during the 2003 rainy season to explore the interactions between salinity and land management in two fields representative of two farming practices:an intensively managed plot with organic inputs and efficient water management,and one without organic matter addition.Field measurements,including pH,Eh,electrical conductivity(EC),and soil solution chemistry,were performed at three depths, with a particular focus on Fe dynamics,inside and outside saline patches. High reducing conditions appeared after flooding particularly in plots receiving organic matter and reduction processes leading to oxide reduction and to the release of Fe and,to a lesser extend,Mn to the soil solution.Oxide reduction led to the consumption of H^+ and the more the Fe reduction was,the higher the pH was,up to 6.5.Formation of hydroxy-green rust were likely to be at the origin of the pH stabilization.In the absence of organic amendments,high salinity prevented the establishment of the reduction processes and pH value remained around 4.Even under high reduction conditions,the Fe concentrations in the soil solution were below commonly observed toxic values and the amended plot had better rice production yield.

Microglial voltage-gated proton channel Hv1 in spinal cord injury

After spinal cord injury,microglia as the first responders to the lesion display both beneficial and detrimental characteristics.Activated microglia phagocyte and eliminate cell debris,release cytokines to recruit peripheral immune cells to the injury site.Excessively activated microglia can aggravate the secondary damage by producing extravagant reactive oxygen species and pro-inflammatory cytokines.Recent studies demonstrated that the voltage-gated proton channel Hv1 is selectively expressed in microglia and regulates microglial activation upon injury.In mouse models of spinal cord injury,Hv1 deficiency ameliorates microglia activation,resulting in alleviated production of reactive oxygen species and pro-inflammatory cytokines.The reduced secondary damage subsequently decreases neuronal loss and correlates with improved locomotor recovery.This review provides a brief historical perspective of advances in investigating voltage-gated proton channel Hv1 and home in on microglial Hv1.We discuss recent studies on the roles of Hv1 activation in pathophysiological activities of microglia,such as production of NOX-dependent reactive oxygen species,microglia polarization,and tissue acidosis,particularly in the context of spinal cord injury.Further,we highlight the rationale for targeting Hv1 for the treatment of spinal cord injury and related disorders.

Cholangiocyte anion exchange and biliary bicarbonate excretion

Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. The excretion of bicarbonate at both the canaliculi and the bile ducts is an important contributor to the generation of the so-called bile-salt independent flow. Bicarbonate is secreted from hepatocytes and cholangiocytes through parallel mechanisms which involve chloride efflux through activation of Cl- channels, and further bicarbonate secretion via AE2/SLC4A2-mediated Cl-/HCO3- exchange. Glucagon and secretin are two relevant hormones which seem to act very similarly in their target cells （hepatocytes for the former and cholangiocytes for the latter）. These hormones interact with their specific G protein-coupled receptors, causing increases in intracellular levels of cAMP and activation of cAMP-dependent Cl- and HCO3- secretory mechanisms. Both hepatocytes and cholangiocytes appear to have cAMP-responsive intracellular vesicles in which AE2/SLC4A2 colocalizes with cell specific Cl- channels （CFTR in cholangiocytes and not yet determined in hepatocytes） and aquaporins （AQP8 in hepatocytes and AQP1 in cholangiocytes）, cAMP-induced coordinated trafficking of these vesicles to either canalicular or cholangiocyte lumenal membranes and further exocytosis results in increased osmotic forces and passive movement of water with net bicarbonate-rich hydrocholeresis.

NHE7 upregulation potentiates the uptake of small extracellular vesicles by enhancing maturation of macropinosomes in hepatocellular carcinoma

Background:Small extracellular vesicles(sEVs)mediate intercellular commu-nication that contributes to hepatocellular carcinoma(HCC)progression via multifaceted pathways.The success of cell entry determines the effect of sEV on recipient cells.Here,we aimed to delineate the mechanisms underlying the uptake of sEV in HCC.Abbreviations:AF,Alexa Fluor;ANOVA,analysis of variance;ATP9A,ATPase Phospholipid Transporting 9A;BCECF-AM,2’,7’-bis-(2-barboxyethyl)-5-(and-6)-carboxyfluorescein,acetoxymethyl ester;BSA,bovine serum albumin;CCMR,Centre for Comparative Medicine Research;CRISPR,clustered regularly interspaced short palindromic repeats;CTL,ctrl;CXCR4,C-X-C Chemokine Receptor Type 4;DAPI,4′,6-diamidino-2-phenylindole;DFS,disease-free survival;DMEM,Dulbecco’s Modified Eagle Medium;DMSO,dimethyl sulfoxide;Dox,doxycycline;EEA1,early endosome antigen 1;EIPA,5-(N-ethyl-N-isopropyl)-amiloride;FBS,fetal bovine serum;FITC,fluorescein isothiocyanate;GAPDH,glyceraldehyde-3-phosphate dehydrogenase;GM130,Golgi matrix protein 130;HCC,hepatocellular carcinoma;HEPES,4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid;HPRT1,hypoxanthine phosphoribosyltransferase 1;H-score,histoscore;IAA,indole-3-acetic acid;KD,knockdown;KO,knockout;mAID,mini-auxin-inducible degron;MTT,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide;NHE7,Na(+)/H(+)exchanger 7;ns,non-significant;OD,optical density;OS,overall survival;PBS,phosphate-buffered saline;PCR,polymerase chain reaction;pHe,endosomal pH;pHi,intracellular pH;PKH67,Paul Karl Horan 67;Rab21,Ras-associated binding protein 21;RIPA,radioimmunoprecipitation assay;SAM,synergistic activation mediator;SEMs,standard error of the means;sEVs,small extracellular vesicles;sgRNA,single-guide RNA;shRNA,short-hairpin RNA;SLC9,solute carrier gene 9;SLiCE,Seamless Ligation Cloning Extract;TCGA,The Cancer Genome Atlas;TCL,total cell lysates;TGN,trans-Golgi network;TMA,tissue microarray;TMR,tetramethyl rhodamine;TSG101,tumor susceptibility gene 101.Yue Yao and Yi Xu contributed equally to this work.Methods:Macropinocytosis was examined by the ability of cells to internalize dextran and sEV.Macropinocytosis was analyzed in Na(+)/H(+)exchanger 7(NHE7)-knockdown and-overexpressing cells.The properties of cells were stud-ied using functional assays.pH biosensor was used to evaluate the intracellular and endosomal pH.The expression of NHE7 in patients’liver tissues was exam-ined by immunofluorescent staining.Inducible silencing of NHE7 in established tumors was performed to reveal the therapeutic potential of targeting NHE7.Results:The data revealed that macropinocytosis controlled the internaliza-tion of sEVs and their oncogenic effect on recipient cells.It was found that metastatic HCC cells exhibited the highest efficiency of sEV uptake relative to normal liver cells and non-metastatic HCC cells.Attenuation of macropinocytic activity by 5-(N-ethyl-N-isopropyl)-amiloride(EIPA)limited the entry of sEVs and compromised cell aggressiveness.Mechanistically,we delineated that high level of NHE7,a sodium-hydrogen exchanger,alkalized intracellular pH and acidized endosomal pH,leading to the maturation of macropinosomes.Inducible inhibition of NHE7 in established tumors developed in mice delayed tumor development and suppressed lung metastasis.Clinically,NHE7 expression was upregulated and linked to dismal prognosis of HCC.Conclusions:This study advances the understanding that NHE7 enhances sEV uptake by macropinocytosis to promote the malignant properties of HCC cells.Inhibition of sEV uptake via macropinocytosis can be exploited as a treatment alone or in combination with conventional therapeutic approaches for HCC.

Anti-corrosive Hybrid Electrolytes for Rechargeable Aqueous Zinc Batteries

Aqueous zinc(Zn)-metal cells with cost-effective components and high safety have long been a promising large-scale energy storage system,but Zn anodes are intrinsically unstable with common aqueous electrolytes,causing substantial underutilization of the theoretical capacity.In this work,we report a strictly neutral aqueous Zn electrolyte at a low cost by leveraging the dynamic hydrolysis equilibrium of a dual-salt Zn(Ac)2/NaAc(Ac:CH3COO−)formulation.With the pH regulation,the corrosion and hydrogen evolution encountered in Zn anodes can be suppressed significantly.This hybrid aqueous electrolyte not only enables dendrite-free Zn plating/stripping at a nearly 95%Coulombic efficiency[an increase of 24%compared to that of the single-salt 1 mol/L Zn(Ac)2 electrolyte],but also supports the reversible operation of Zn cells paired with either Na3V2(PO4)3 or iodine cathodes—the former delivers a high output voltage of 1.55 V with an energy level of 99.5 W·h/kg(based on the mass of the cathode),and the latter possesses a high specific capacity of 110.9 mA·h/g while yielding long-term cyclability(thousands of cycles).These findings open up a new avenue of modifying practical electrolytes having targeted properties to stabilize multivalent metal anodes.