Effectively Increasing Pt Utilization Efficiency of the Membrane Electrode Assembly in Proton Exchange Membrane Fuel Cells through Multiparameter Optimization Guided by Machine Learning.

Although proton exchange membrane fuel cells have received attention, the high costs associated with Pt-based catalysts in membrane electrode assemblies (MEAs) remain a huge obstacle for large-scale applications. To solve this urgent problem, the utilization efficiency of Pt in MEAs must be increased. Facing numerous interacting parameters in an attempt to keep experimental costs as low as possible, we innovatively introduce machine learning (ML) to achieve this goal. Nine different ML algorithms are trained on the experimental dataset from our laboratory to precisely predict the performance and Pt utilization (maximum R2 = 0.973/0.968). To determine the best synthesis conditions, black-box interpretation methods are applied to provide reliable insights from both qualitative and quantitative perspectives. The optimized choices of ionomer/catalyst ratio, water content, organic solvent, catalyst loading, stirring method, solid content, and ultrasonic spraying flow rate are properly made with few experimental attempts under ML results' guidance. Promising Pt utilization of 0.147 gPt kW-1 and a power density of 1.02 W cm-2 are achieved at 0.6 V in a single cell (H2/air) at an ultralow total loading of 0.15 mg Pt cm-2. Therefore, this work contributes to the economy of hydrogen energy by paving the way for MEA optimization with complex parameters by ML.

Metal-organic framework derived leaf-like CoSNC nanocomposites for supercapacitor electrodes.

The designed construction of micro-/nano-structures and multi-composites on electrodes showed a promising prospect to improve electrochemical properties in supercapacitors. Herein, a facile carbonizing strategy was adopted for fabricating leaf-like CoSNC nanocomposites, which possess both the sheet structure and multi-composites of well-dispersed CoS2 nanoparticles in N-doped carbon frameworks. First, the leaf-like nanocomposites with high aspect ratios effectively shortened the ion/electron transmission paths and exposed more faradaic redox sites. Second, the N-doped carbon frameworks could stabilize the electrode structure during charge/discharge processes. Third, the well-dispersed CoS2 nanoparticles could also enhance the electrochemical kinetics. Hence, leaf-like CoSNC nanocomposites as electrode materials exhibited high specific capacitance, good rate capacity and cycling stability.

Coprecipitation-Gel Synthesis and Degradation Mechanism of Octahedral Li1.2Mn0.54Ni0.13Co0.13O2 as High-Performance Cathode Materials for Lithium-Ion Batteries.

The octahedral core-shell Li-rich layered cathode material of Li1.2Mn0.54Ni0.13Co0.13O2 can be synthesized via an ingenious coprecipitation-gel method without subsequent annealing. On the basis of detailed X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy characterizations, it is suggested that the as-prepared material consists of an octahedral morphology and a new type of core-shell structure with a spinel-layered heterostructure inside, which is the result of overgrowth of the spinel structure with {111} facets on {001} facets of the layered structure in a single orientation. The surface area of Li1.2Mn0.54Ni0.13Co0.13O2 crystals where the spinel phase is located possesses sufficient Li and O vacancies, resulting in the reinsertion of Li into position after the first charge and maintenance of the interface stability via the replenishment of oxygen from the bulk region. Compared to that synthesized by the traditional coprecipitation method, the Li1.2Mn0.54Ni0.13Co0.13O2 synthesized by the coprecipitation-gel method exhibits higher discharge capacity and Coulombic efficiency, from 73.9% and 251.5 mAh g-1 for the spherical polycrystal material to 86.2% and 291.4 mAh g-1.

Hierarchical Porous NiO/ß-NiMoO4 Heterostructure as Superior Anode Material for Lithium Storage.

Ternary transition metal oxides (TTMOs) have attracted considerable attention for rechargeable batteries because of their fascinating properties. However, the unsatisfactory electrochemical performance originating from the poor intrinsic electronic conductivity and inferior structural stability impedes their practical applications. Here, the novel hierarchical porous NiO/ß-NiMoO4 heterostructure is fabricated, and exhibits high reversible capacity, superior rate capability, and excellent cycling stability in Li-ion batteries (LIBs), which is much better than the corresponding single-phase NiMoO4 and NiO materials. The significantly enhanced electrochemical properties can be attributed to its superior structural characteristics, including the large surface area, abundant pores, fast charge transfer, and catalytic effect of the intermediate product of metallic nickel. The NiO/ß-NiMoO4 heterostructure delivers a high capacity of 1314 mA h g-1 at 0.2 A g-1 after 100 cycles. Furthermore, even after 400 cycles at 1 A g-1 , the reversible capacity remains at around 500 mA h g-1 . These results indicate that the NiO/ß-NiMoO4 heterostructure shows great potential as an anode material for high-performance LIBs.

Primary Left Tibial Epithelioid Hemangioendotheliomas With Multiple Metastases Revealed by FDG PET/CT Imaging.

Bone epithelioid angiosarcoma is an extremely rare osseous malignancy with an aggressive and destructive biological behavior. We present FDG PET/CT findings of a 59-year-old woman with left lower limb pain for 1 month. The images revealed abnormal activity in both left fibula and left tibia. In addition, abnormal activity in the sacrum and enlarged retroperitoneal lymph nodes was also noted. Pathological examination demonstrated bone epithelioid angiosarcoma.

[Submucosal tunneling endoscopic resection in the treatment of esophageal submucosal tumors originating from muscularis propria layer].

OBJECTIVE: To evaluate the short-term outcomes and complication management of submucosal tunneling endoscopic resection(STER) for esophageal submucosal tumors (SMTs) originating from the muscularis propria(MP) layer. METHODS: Clinical data of 48 patients with esophageal SMTs from MP layer undergoing STER in the Department of Gastroenterology, the First People's Hospital of Xiangshan, Zhejiang, and the Endoscopy Center of Zhongshan Hospital, Fudan University, Shanghai between September 2013 and August 2014 were retrospectively analyzed. The clinicopathological features, complication management, and short-term outcomes were evaluated. RESULTS: All the patients underwent STER successfully. The complete resection rate was 100%. The mean maximum diameter of the lesions was (22.9±12.1) mm (range 9.0-60.0 mm), and the mean operation time 41.8 min (range 15.0-140.0 min). Intraoperative mucosal injury occurred in 5 patients (10.4%), which was successfully clipped, pneumoperitoneum in 2 patients (4.2%) and subcutaneous emphysema in 3 patients(6.3%), which were successfully controlled with conservative treatments. Five patients (10.4%) had postoperative severe chest pain. Seven patients (14.6%) developed fever, among them, 5 were managed by conservative therapy, and 2 were submucosal tunnel infection, who were successfully treated after reclosing the ruptured tunnel entry with clips. All the removed tumors had tumor-free resection margins. The average length of postoperative hospital stay was 2.4 days (range 1-13 days). Local recurrence and distant metastasis did not occur during mean 6.8 months (range 2-12 months) follow up. CONCLUSIONS: STER appears to be a safe and effective option for esophageal SMTs originating from MP layer. Common complications related to STER often can be successfully controlled with conservative treatments.

99mTc-MDP uptake in implantation metastasis of gastric cancer: the additional value of SPECT/CT.

A 47-year-old woman with a history of subtotal gastrectomy due to gastric cancer underwent bone scintigraphy to evaluate possible recurrent disease. The whole-body images revealed a single focus of elevated 99mTc-MDP activity in the right pubic region, which was located in the intrapelvic soft tissue on subsequent SPECT/CT images. Pathological examination after needle biopsy demonstrated that the soft tissue was an implantation metastasis from gastric cancer.