Nanostructural Perspective for Destabilization of Mg Hydride Using the Immiscible Transition Metal Mn.

Phase segregation in hydride-forming alloys may persist under the action of multiple hydrogenation/dehydrogenation cycles. We use this effect to destabilize metal hydrides in the immiscible Mg-Mn system. Here, in the MgxMn1-x thin films, the Mg and Mn domains are chemically segregated at the nanoscale. In Mn-rich compositions, the desorption pressure of hydrogen from MgH2 is elevated at a given temperature, indicating a thermodynamic destabilization. The increase in the desorption pressure of hydrogen reaches ∼2.5 orders in magnitude for x = 0.30 at moderate temperatures. Such large thermodynamic destabilization allows the MgH2 to reversibly absorb and desorb hydrogen even at room temperature. Our strategy to use immiscible elements for destabilization of MgH2 is effective and opens up the possibility for the development of advanced and low-cost hydrogen storage and supply systems.

Destabilizing the Dehydrogenation Thermodynamics of Magnesium Hydride by Utilizing the Immiscibility of Mn with Mg.

Hydrogen storage is a key technology for the advancement of hydrogen and fuel cell power technologies in stationary and portable applications. MgH2, an example of a high-capacity hydrogen storage material, has two major material challenges for practical applications: slow hydrogen desorption kinetics and high hydrogen desorption temperature. Numerous studies have reported enhancements in kinetics but only a few in thermodynamics. Here, we present a simple but effective way to improve upon both the kinetic and thermodynamic aspects of desorption by utilizing the immiscibility of Mn, a non-hydrogen absorbing metal, with Mg. Mg0.25Mn0.75, prepared through ball milling MgH2 and Mn powders, is a nanocomposite where the nanometer-sized MgH2 domains are randomly embedded in a Mn matrix. This sample readily and reversibly absorbs and desorbs deuterium even at a temperature of 200 °C without the addition of any catalysts. This is nearly 180 °C lower than the typical operating temperature of conventional bulk Mg. Furthermore, at a given temperature, its deuterium desorption pressure is clearly elevated compared to that of pure Mg, indicating the destabilization of MgD2. The average crystallite size of MgD2 in deuterated Mg0.25Mn0.75 determined from X-ray diffraction data is around 9 nm. Nuclear magnetic resonance spectroscopy studies show that MgD2 domains are heavily strained and some of the D atoms are coordinated by a few Mn atoms, suggesting that a large number of lattice defects, including the partial substitution of Mg with Mn, are introduced during ball milling. Furthermore, the Mn matrix firmly locks nanosized MgD2, preventing the agglomeration of MgD2 below 250 °C. Our study suggests that a synergistic effect created by nanosizing, large lattice distortions, and robust interfaces between MgD2 and the Mn matrix can effectively and concurrently improve the kinetics and thermodynamics of MgD2 in Mg0.25Mn0.75. Our work demonstrates the possibility of utilizing the immiscibility of metals with Mg to synthesize a robust nanostructure that can alter the kinetics and stability of MgH2.

Clinical analysis of treatment of airway stenosis caused by advanced central lung cancer with bronchoscopic endobronchial ultrasound guided intratumoral injection of Cisplatin (10 cases) / 中国内镜杂志

Objective To explore the clinical application value of bronchoscopic endobronchial ultrasound (EBUS) guided intratumoral injection of Cisplatin in treatment of airway stenosis caused by advanced central lung cancer. Methods The clinical data of 10 cases of airway stenosis caused by advanced central lung cancer between Nov 2015 and Jan 2017 were analyzed retrospectively. Results 10 cases airway stenosis caused by advanced central lung cancer received EBUS guided intratumoral injection of Cisplatin treatment. Assessed by bronchoscopic, there were 8 cases of patients showed favorable effects after the treatment; Assessed by CT scan, 6 cases showed effects;And 8 cases relieved dyspnea. Conclusion EBUS guided intratumoral injection of Cisplatin in treatment of airway stenosis caused by advanced central lung cancer have some effect.

Value of non-real-time radial probe endobronchial ultrasound guided transbronchial lung biopsy in the diagnosis of peripheral lung cancer and analysis of false negative results / 中国内镜杂志

Objective To explore the diagnostic value of non-real-time radial probe endobronchial ultrasound (RP-EBUS) guided transbronchial lung biopsy (TBLB) for peripheral lung cancer and analysis of false negative results. Methods A retrospective analysis of the clinical and imaging data of 256 patients with peripheral lung cancer between March 2013 and December 2016, all the cases underwent non-real-time RP-EBUS guided TBLB, then evaluate its significance in the diagnosis of peripheral lung cancer and analyze the reasons of false negative results. Result In 256 patients who received non-real-time RP-EBUS examinations, 73.83% (189/256) of peripheral lung cancer were detected by RP-EBUS and the positive rate of RP-EBUS guided TBLB was 61.33% (157/256). The positive rate of non-real-time RP-EBUS guided TBLB was correlated with lesions >2 cm in diameter, lesions close to visceral pleura, ultrasonic image characteristics and the RP-EBUS probe surrounding by lesion (P < 0.05). The positive rate of non-real-time RP-EBUS guided TBLB was not correlated with RP-EBUS probe passed through lesions and times of biopsy (P > 0.05). Complications including bleeding, chest pain and pneumothorax recovered spontaneously. Conclusion Non-real-time RP-EBUS guided TBLB was a practical technology for diagnosis of peripheral lung cancer with high diagnostic rate and good safety. Lesion size, connection to visceral pleura, ultrasonic image characteristics and the RP-EBUS probe surrounding by lesion influenced the diagnostic yield. Improvement of operative skills can reduce false negative results.

Thermodynamic Tuning of Mg-Based Hydrogen Storage Alloys: A Review.

Mg-based hydrides are one of the most promising hydrogen storage materials because of their relatively high storage capacity, abundance, and low cost. However, slow kinetics and stable thermodynamics hinder their practical application. In contrast to the substantial progress in the enhancement of the hydrogenation/dehydrogenation kinetics, thermodynamic tuning is still a great challenge for Mg-based alloys. At present, the main strategies to alter the thermodynamics of Mg/MgH2 are alloying, nanostructuring, and changing the reaction pathway. Using these approaches, thermodynamic tuning has been achieved to some extent, but it is still far from that required for practical application. In this article, we summarize the advantages and disadvantages of these strategies. Based on the current progress, finding reversible systems with high hydrogen capacity and effectively tailored reaction enthalpy offers a promising route for tuning the thermodynamics of Mg-based hydrogen storage alloys.

[A comparative study on manual and coaxial automated percutaneous lung biopsy].

OBJECTIVE: To evaluate the difference in diagnostic accuracy and complication rate and operational procedures between manual and coaxial automated percutaneous lung biopsy under CT-guidance. METHODS: Ninety-seven patients [aged from 19 - 87 (50 ± 17) years], with undiagnosed pulmonary lesions underwent CT-guided percutaneous lung biopsy from June 2006 to May 2010 in this hospital. The final diagnosis was confirmed by surgical pathology or clinical follow-up. Fifty-three patients (32 males and 21 females) underwent manual percutaneous lung biopsy, while 44 patients (29 males and 15 females) underwent percutaneous lung biopsy by using a coaxial automated biopsy device (biopsy gun). Biopsies were carried out by the same physician in all cases with the 18G vitesse needle made by optimed company in German. Biopsy guns made by the same company were used in coaxial automated biopsy group. The puncture point, angle and depth were set according to the CT images under the guidance by CT grating. Generally, the puncture was directed vertically towards the lesions closest to the chest wall. RESULTS: In the manual biopsy group, the diagnostic accuracy was 91% (48/53), the pneumothorax rate was 11% (6/53), and the hemorrhage rate was 15% (8/53), while in the coaxial automated biopsy group, they were 75% (33/44), 30% (13/44) and 27% (12/44), respectively. CONCLUSION: The diagnostic accuracy was higher while the pneumothorax rate was lower in the manual biopsy as compared to the coaxial automated biopsy group.

[A comparative research on the conventional transbronchial needle aspiration and endobronchial ultrasound-guided transbronchial needle aspiration for the diagnosis of mediastinum lesions].

OBJECTIVE: To compare the diagnostical yields and complication of conventional transbronchial needle aspiration (TBNA) and endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) for the mediastinum lesions under the same condition. METHOD: Ninety-five patients with mediastinal lesions on chest CT were included. Bronchoscopy was performed under the local anesthesia, TBNA, EBUS-TBNA performed sequentially as a single combined procedure. RESULTS: Of the 71 patients confirmed to be malignant, the positive rate of TBNA was 92% (65/71), and 96% (68/71) by EBUS-TBNA. There was no difference in malignant and benign lesions between conventional TBNA and EBUS-TBNA, but the success rate for obtaining adequate samples was higher by EBUS-TBNA (39/95) as compared to TBNA (22/95). Accidental injury of the blood vessels occurred in 7 cases by TBNA as compared to 3 cases by EBUS-TBNA, but the difference was not significant. CONCLUSION: Satisfactory diagnostic yields can be obtained by either conventional TBNA or EBUS-TBNA in skilled hands.