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Geothermal energy, as a clean and renewable resource distributed worldwide, has received extensive focus in recent years. With the improvement in drilling and logging technology, the depth of geothermal exploration has gradually increased. Carbonate reservoirs are presently the main layer for geothermal development and use in China that have the characteristics of wide distribution, large reserves, and easy reinjection. The current use is limited to the strong karst development zone, approximately 200 m at the top of the reservoirs. Because of the low permeability and strong heterogeneity, the deep carbonate geothermal reservoirs cannot be commercially developed. This study aims to solve the key technical problems of efficiently developing deep carbonate geothermal reservoirs with extreme thickness. The target section was selected by analyzing comprehensive logging and fracture imaging logging data. An innovative simulation technology combining hydraulic jetting and acid fracturing is developed, which has the characteristics of fixed-point fracturing, effective sealing, strong penetration, and a large stimulation range. A production enhancement test was conducted for carbonate geothermal wells in the following order: comprehensive logging, imaging logging, casing cementing, perforation, pumping test, small pressure test, hydraulic injection acid fracturing, pumping test (after fracturing), and other construction processes. Comprehensive logging is an effective means to interpret the macroscopic pore and permeability properties of a reservoir and can be used to initially select the target geothermal reservoir. Fracture imaging logging can provide a more intuitive understanding of fracture development and distribution characteristics. The results show that the fracture density of geothermal well D22 does not decrease substantially with increasing depth, and the fracture width tends to decrease with depth clearly. The experimental geothermal well D22, which has the largest thickness of carbonate geothermal reservoir exposed in the Xiong'an New Area, was selected to perform a pilot field test of stimulation. The results show that the water inflow of the target section at 3024–3174 m increased from 4.72 m3·h−1 before stimulation to 44.10 m3·h−1 after stimulation, increasing by 8.3-fold. The unit water inflow increased from 0.024 m3·(h·m)−1 before stimulation to 0.745 m3·(h·m)−1 after stimulation, increasing by 30-fold. The reservoir permeability coefficient increased from 4.4×10−3 m·d−1 to 146.3×10−3 m·d−1. The wellhead water temperature increased from 60.0 °C before stimulation to 66.5 °C after stimulation. Therefore, the development potential of deep and thick carbonate geothermal reservoirs can be substantially improved through the developed stimulation. This research can provide technical support for the large-scale development of geothermal resources in China.

Disturbance of the cholinergic system plays a crucial role in the pathological progression of neurological diseases that cause dyskinesia-like behaviors. However, the molecular mechanisms underlying this disturbance remain elusive. Here, we showed that cyclin-dependent kinase 5 (Cdk5) was reduced in cholinergic neurons of midbrain according to the single-nucleus RNA sequencing analysis. Serum levels of CDK5 also decreased in patients with Parkinson’s disease accompanied by motor symptoms. Moreover, Cdk5 deficiency in cholinergic neurons triggered paw tremors, abnormal motor coordination, and motor balance deficits in mice. These symptoms occurred along with cholinergic neuron hyperexcitability and increases in the current density of large-conductance Ca2+-activated K+ channels (BK channels). Pharmacological inhibition of BK channels restrained the excessive intrinsic excitability of striatal cholinergic neurons in Cdk5-deficient mice. Furthermore, CDK5 interacted with BK channels and negatively regulated BK channel activity via phosphorylation of threonine-908. Restoration of CDK5 expression in striatal cholinergic neurons reduced dyskinesia-like behaviors in ChAT-Cre;Cdk5f/f mice. Together, these findings indicate that CDK5-induced phosphorylation of BK channels involves in cholinergic-neuron-mediated motor function, providing a potential new therapeutic target for treating dyskinesia-like behaviors arising from neurological diseases.

In this paper, a direct numerical simulation (DNS) of dielectric fluid flow subjected to unipolar injection under an alternating current (AC) electric field is carried out. The effect of frequency f of pulsed direct current (PDC) and AC on the transient evolution of electroconvection and their subcritical bifurcations are investigated in details. Electroconvection under PDC or AC tends to exhibit oscillating flow due to the periodic boundary condition of charge density and potential compared to the direct current (DC) case. The results demonstrate that under the PDC field, the linear criterion Tc decreases with increasing frequency, while the nonlinear stability criterion Tf is hardly affected. Under the AC field, a critical frequency fc = 0.0316 is found, which separates electroconvection into two typical flow regimes—periodic flow regime (f

DNA G-quadruplexes occur in oncologically relevant regions, thus are interesting targets for cancer research and treatment. Here, the authors solved the 1:1 and 4:2 (ligand/DNA) NMR structures of human telomeric DNA in complex with platinum(II)-tripod ligand and show that the binding is dynamic.

In this study, sodium alginate (SA), dimethyl dodecyl betaine (BS), and chitosan (CS) were used for single, binary, and ternary modifications on the surface of semi-carbonized fibers (Sf) prepared using acrylic fiber. Batch method was used to investigate the adsorption characteristic of oxytetracycline (OTC) on the tested materials, and the effects of pH, temperature, and ionic strength on oxytetracycline adsorption were compared. The structural particularities of the tested materials was studied using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). Results showed that: (1) Langmuir model can better fitted the adsorption isotherms of OTC than Henry and Freundlich models, with the maximum adsorption capacity (qm) maintained at 16.11– 65.25 mmol/kg. The qm of oxytetracycline presented the trend of ternary > binary > single modification. (2) In the pH range of 1–9 and ionic strength range of 0.01–0.5 mol/L, the adsorption amount of OTC on different modified Sfs increased first and then decreased with increasing pH and ionic strength, reaching the maximum value at pH 5 and ionic strength of 0.1 mol/L. (3) OTC adsorption on different modified Sfs increased with the increase in temperature, and the adsorption was a spontaneous, endothermic, and entropy-increasing process, which conformed to the pseudo-second-order kinetic equation. (4) SEM and FTIR results proved that the modifiers were modified on the surface and that they changed the surface properties of Sf. The adsorption amount of OTC on 100SA/BS/ CS-Sf still reached about 50% of the original material after three times of regeneration. [ABSTRACT FROM AUTHOR]