Anisotropic s-Wave Gap in the Vicinity of a Quantum Critical Point in Superconducting BaFe_(2)(As_(1-x)P_(x))_(2) Single Crystals:A Study of Point-Contact Spectroscopy

We report on soft c-axis point-contact Andreev reflection(PCAR)spectroscopy combining with resistivity measurements on BaFe_(2)(As_(0.7)P_(0.3))_(2),to elucidate the superconducting gap structure in the vicinity of the quantum critical point.A double peak at the gap edge plus a dip feature at zero-bias has been observed on the PCAR spectra,indicative of the presence of a nodeless gap in BaFe_(2)(As_(0.7)P_(0.3))_(2).Detailed analysis within a sophisticated theoretical model reveals an anisotropic gap with deep gap minima.The PCARs also feature additional structures related to the electron-bosonic coupling mode.Using the extracted superconducting energy gap value,a characteristic bosonic energy Ω_(b) and its temperature dependence are obtained,comparable with the spin-resonance energy observed in neutron scattering experiment.These results indicate a magnetism-driven quantum critical point in the BaFe_(2)(As_(1-x)P_(x))_(2) system.

Tunneling Barrier Thickness Dependence of Spin Polarization of Ferromagnet in Magnetic Tunnel Junctions

For designing low-impedance magnetic tunnel junctions(MTJs),it has been found that tunneling magnetoresistance strongly correlates with the insulating barrier thickness,imposing a fundamental problem about the relationship between spin polarization of ferromagnet and the insulating barrier thickness in MTJs.Here,we investigate the influence of alumina barrier thickness on tunneling spin polarization(TSP)through a combination of theoretical calculations and experimental verification.Our simulating results reveal a significant impact of barrier thickness on TSP,exhibiting an oscillating decay of TSP with the barrier layer thinning.Experimental verification is realized on FeNi/AlO_(x)/Al superconducting tunnel junctions to directly probe the spin polarization of FeNi ferromagnet using Zeeman-split tunneling spectroscopy technique.These findings provide valuable insights for designs of high-performance spintronic devices,particularly in applications such as magnetic random access memories,where precise control over the insulating barrier layer is crucial.

Resistance fluctuations in superconducting K_(x)Fe_(2-y)Se_(2) single crystals studied by low-frequency noise spectroscopy

Low-frequency resistance noise spectroscopy is applied to investigate bulk single crystals of the intercalated ironselenide K_(x)Fe_(2-y)Se_(2) superconductors with different iron vacancy orders.Based on a generalized fluctuation model,the well-observed resistance hump above 100 K is interpreted as an insulator-metal phase transition with a characteristic transition energy of 0.1-0.6 eV,indicating a highly inhomogeneous energy distribution configuration.In the superconducting transition regime,we find that the normalized resistance noise scales with resistance R excellently as S_(R)/R^(2)∝R^(l_(rs)) with the noise exponent lrs≈1.4.With reduced iron vacancy disordering in enhanced superconductivity K_(x)Fe_(2-y)Se_(2) crystals,the level of resistance fluctuations is greatly suppressed,suggesting a geometrical phase transition for conduction channel,which is directly related to the microstructure of the crystals.

Progress in preventive effects of cordyceps sinensis on ischemic brain

Cerebral ischemia is due to cerebral blood supply disorders caused by ischemia and hypoxia resulting in localized ischemic brain necrosis or brain softening of the disease,leading to irreversible brain damage and subsequent loss of neuronal function is a serious threat to human health One of several diseases.For patients with cerebral ischemia,often the lack of effective and extensive treatment.In addition,cerebral ischemia with morbidity,morbidity and mortality are characterized by high,so by the medical profession at home and abroad attention.As a traditional Chinese medicine,cordyceps sinensis(CS)is a complex of ergot fungus,which is parasitized on the larvae of the bat-moth family.The compound is composed of cordycepin,cordyceps polysaccharide,cordyceps sinensis peptides,ergosterol,mannitol,fatty acids and trace elements such as a variety of ingredients,with a wide range of pharmacological effects.Over the years,domestic and foreign scholars on the pharmacological effects of cordyceps sinensis were more comprehensive study of its prevention and treatment of cerebral ischemia is also deepening,found that cordyceps sinensis on cerebral ischemia with anti-inflammatory,reduce oxidative damage and neuronal ischemia damage,reduce neuronal apoptosis,improve memory cognition,reduce thrombosis,inhibit NO production,enhance mitochondrial energy supply,scavenging free radicals and other prevention and treatment.But no relevant review.In this paper,the domestic and foreign literatures on the prevention and treatment of cerebral ischemia by cordyceps sinensis were summarized,analyzed and summarized in order to provide useful information for the research and further development of cordyceps sinensis.

Difficult airway due to cervical haemorrhage caused by spontaneous rupture of a parathyroid adenoma: A case report

BACKGROUND Cervical haemorrhage due to spontaneous rupture of a parathyroid adenoma is a rare complication that may cause life-threatening acute airway compromise.CASE SUMMARY A 64-year-old woman was admitted to the hospital 1 day after the onset of right neck enlargement, local tenderness, head-turning difficulty, pharyngeal pain, and mild dyspnoea. Repeat routine blood testing showed a rapid decrease in the haemoglobin concentration, indicating active bleeding. Enhanced computed tomography images showed neck haemorrhage and a ruptured right parathyroid adenoma. The plan was to perform emergency neck exploration, haemorrhage removal, and right inferior parathyroidectomy under general anaesthesia. The patient was administered 50 mg of intravenous propofol, and the glottis was successfully visualised on video laryngoscopy. However, after the administration of a muscle relaxant, the glottis was no longer visible and the patient had a difficult airway that prevented mask ventilation and endotracheal intubation. Fortunately, an experienced anaesthesiologist successfully intubated the patient under video laryngoscopy after an emergency laryngeal mask placement. Postoperative pathology showed a parathyroid adenoma with marked bleeding and cystic changes. The patient recovered well without complications.CONCLUSION Airway management is very important in patients with cervical haemorrhage. After the administration of muscle relaxants, the loss of oropharyngeal support can cause acute airway obstruction.Therefore, muscle relaxants should be administered with caution. Anaesthesiologists should pay careful attention to airway management and have alternative airway devices and tracheotomy equipment available.

Infection-responsive long-term antibacterial bone plates for open fracture therapy

The infections in open fracture induce high morbidity worldwide.Thus,developing efficient anti-infective orthopedic devices is of great significance.In this work,we designed a kind of infection-responsive long-term antibacterial bone plates.Through a facile and flexible volatilization method,a multi-aldehyde polysaccharide derivative,oxidized sodium alginate,was crosslinked with multi-amino compounds,gentamycin and gelatin,to fabricate a uniform coating on Ti bone plates via Schiff base reaction,which was followed by a secondary crosslinking process by glutaraldehyde.The double-crosslinked coating was stable under normal condition,and could responsively release gentamycin by the triggering of the acidic microenvironment caused by bacterial metabolism,owning to the pH-responsiveness of imine structure.The thickness of the coating was ranging from 22.0μm to 63.6μm.The coated bone plates(Ti-GOGs)showed infection-triggered antibacterial properties(>99%)and high biocompatibility.After being soaked for five months,it still possessed efficient antibacterial ability,showing its sustainable antibacterial performance.The in vivo anti-infection ability was demonstrated by an animal model of infection after fracture fixation(IAFF).At the early stage of IAFF,Ti-GOGs could inhibit the bacterial infection(>99%).Subsequently,Ti-GOGs could promote recovery of fracture of IAFF.This work provides a convenient and universal strategy for fabrication of various antibacterial orthopedic devices,which is promising to prevent and treat IAFF.

Polycaprolactone/polysaccharide functional composites for lowtemperature fused deposition modelling

Fused deposition modelling(FDM)is a commonly used 3D printing technology.The development of FDM materials was essential for the product quality of FDM.In this work,a series of polycaprolactone(PCL)-based composites for low-temperature FDM were developed.By melt blending technique,different ratios of starch were added into PCL to improve the performances of FDM,and the printability,tensile strength,rheological properties,crystallization behaviors and biological performances of the composites were studied.The PCL/starch composite had the best performance in FDM process with the starch ratio of 9 ph at 80–90°C.The melting strength and solidification rate of PCL/starch composites were improved.The starch also increased the crystallization temperature,degree of crystallinity and crystallization rate of PCL/starch composites,while had no negative effects on the tensile strength of PCL.Due to the low printing temperature,various kinds of bioactive components were added into PCL/starch composites for preparation of antibacterial and biocompatible materials for FDM.The present work provides a new method to develop novel low-temperature FDM materials with various functions.

Sensitive Analysis and Pharmacokinetic Study of Berberrubine Using LC-MS/MS

Objective To develop a sensitive and reproducible liquid chromatography-tandem mass spectrometry（LC-MS/MS） method to evaluate the pharmacokinetic behavior of berberrubine（BRB） and its glucuronide（BRBG） in rats. Methods BRB, BRBG and tetrahydroberberine（THB, internal standard） were isolated by liquid-liquid extraction in rat biological samples. Chromatographic separation was achieved on an Agilent Zorbax Eclipse Plus C_（18）（2.1 mm × 50 mm, 3.5-Micron） with a gradient mobile phases primarily containing acetonitrile, water with 0.1% formic acid and 5 mm ammonium acetate. The analytes were monitored by MS/MS in positive electrospray ionization mode. Herein, the feasibility of new developed method was validated with respect to specificity, linearity, precision, accuracy, stability, extraction efficiency and matrix effect. The appropriate method was used for the pharmacokinetic study in rats.Results The new developed method could be applied to the pharmacokinetic study of BRB in rats. BRB and BRBG showed good linearity over the ranges of 2-1000 ng/mL and 5-2000 ng/mL, respectively, and precision was no more than 15%. The accuracy, specificity and stability could be acceptable. Conclusion The new method is sensitive and reproducible. In pharmacokinetic study, BRB showed nonlinear elimination property. Meanwhile, BRB was rapidly absorbed and widely distributed in various tissues with the highest exposure of BRB in kidney and liver. The absolute bioavailability of BRB was determined to be 8.2% and at the dose of 40 mg/kg, a total of 44% BRB was excreted in urine and feces.

Efficient synthesis of panaxadiol derivatives using continuous-flow microreactor and evaluation of anti-tumor activity

An efficient method has been developed for the synthesis of a series of（20R）-panaxadiol derivatives（4a–w） using a continuous-flow microreactor.The antitumor activities of the newly synthesized compounds were evaluated in vitro in two human prostate adenocarcinoma tumor cell lines（i.e.,PC-3and LNCa P cells）,and their cytotoxicities were evaluated using a standard MTT assay.Compounds 4c,4h,4p,4q and 4s exhibited higher antitumor activities toward PC-3 cell line than panaxadiol,which was used as a reference standard.