Microporous Binder for the Silicon-Based Lithium-Ion Battery Anode with Exceptional Rate Capability and Improved Cyclic Performance.

Silicon anodes have attracted much attention owing to their high theoretical capacity. Nonetheless, an inevitable and enormous volumetric expansion of silicon in the lithiated state restrained the development of the silicon anode for lithium-ion batteries. Fortunately, the utilization of the high-performance binder is a promising and effective way to overcome such obstacles. Herein, a polymer of intrinsic microporosity (PIM) is applied as the binder for the silicon anode, which is composed of a rigid polymer backbone, an intrinsic porous structure, and active carboxyl groups (PIM-COOH). Compared to the traditional binder, both the long-term stability and rate performance of the electrode using PIM-COOH as the binder are significantly improved. The mechanism responsible for the enhanced performance is investigated. The PIM-COOH binder provides stronger adhesion toward the current collector than the conventional binders. The unique rigid polymer backbone and porous structure of the PIM-COOH binder enable a good capability to withstand the volume change and external stress generated by the Si anode. The porous structure of the PIM-COOH binder enhances lithium-ion transportation compared to the SA binder, which improves rate performance of the silicon anode. This work provides a unique insight into design, synthesis, and utilization of the binders for lithium-ion batteries.

Artificial Intelligence Algorithm-Based Intraoperative Magnetic Resonance Navigation for Glioma Resection.

The study aimed to analyze the application value of artificial intelligence algorithm-based intraoperative magnetic resonance imaging (iMRI) in neurosurgical glioma resection. 108 patients with glioma in a hospital were selected and divided into the experimental group (intraoperative magnetic resonance assisted glioma resection) and the control group (conventional surgical experience resection), with 54 patients in each group. After the resection, the tumor resection rate, NIHSS (National Institute of Health Stroke Scale) score, Karnofsky score, and postoperative intracranial infection were calculated in the two groups. The results revealed that the average tumor resection rate in the experimental group was significantly higher than that in the control group (P < 0.05). There was no significant difference in Karnofsky score before and after the operation in the experimental group (P > 0.05). There was no significant difference in NIHSS score between the experimental group and the control group after resection (P > 0.05). The number of patients with postoperative neurological deficits in the experimental group was smaller than that in the control group. In addition, there was no significant difference in infection rates between the two groups after glioma resection (P > 0.05). In summary, intraoperative magnetic resonance navigation on the basis of a segmentation dictionary learning algorithm has great clinical value in neurosurgical glioma resection. It can maximize the removal of tumors and ensure the integrity of neurological function while avoiding an increased risk of postoperative infection, which is of great significance for the treatment of glioma.

Artificial Intelligence Algorithm-Based Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) in the Treatment of Glioma Biopsy.

This study was aimed at exploring the application value of positron emission tomography (PET) + magnetic resonance imaging (MRI) technology based on convolutional neural network (CNN) in the biopsy and treatment of intracranial glioma. 35 patients with preoperatively suspicious gliomas were selected as the research objects. Their imaging images were processed using CNN. They were performed with the preoperative head MRI, fluorodeoxyglucose (FDG) PET, and ethylcholine (FECH) PET scans to construct the cancer tissue contours. In addition, the performance of CNN was evaluated, and the postoperative pathology of patients was analyzed. The results suggested that the CNN-based PET + MRI technology showed a recognition accuracy of 97% for images. Semiquantitative analysis was adopted to analyze the standard uptake value (SUV). It was found that the SUVFDG and SUVFECH of grade II/III glioma were 9.77 ± 4.87 and 1.82 ± 0.50, respectively, and the SUVFDG and SUVFECH of grade IV glioma were 13.91 ± 1.83 and 3.65 ± 0.34, respectively. According to FDG PET, the mean value of SUV on the lesion side of grade IV glioma was greater than that of grade II-III glioma, and the difference was significant (P < 0.05), and similar results were obtained on FECH PET. It showed that CNN-based PET + MRI fusion technology can effectively improve the recognition effect of glioma, can more accurately determine the scope of glioma lesions, and can predict the degree of malignant glioma to a certain extent.

Impact of CO2 activation on the structure, composition, and performance of Sb/C nanohybrid lithium/sodium-ion battery anodes.

Antimony (Sb) has been regarded as one of the most promising anode materials for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) and attracted much attention in recent years. Alleviating the volumetric effect of Sb during charge and discharge processes is the key point to promote Sb-based anodes to practical applications. Carbon dioxide (CO2) activation is applied to improve the rate performance of the Sb/C nanohybrid anodes caused by the limited diffusion of Li/Na ions in excessive carbon components. Based on the reaction between CO2 and carbon, CO2 activation can not only reduce the excess carbon content of the Sb/C nanohybrid but also create abundant mesopores inside the carbon matrix, leading to enhanced rate performance. Additionally, CO2 activation is also a fast and facile method, which is perfectly suitable for the fabrication system we proposed. As a result, after CO2 activation, the average capacity of the Sb/C nanohybrid LIB anode is increased by about 18 times (from 9 mA h g-1 to 160 mA h g-1) at a current density of 3300 mA g-1. Moreover, the application of the CO2-activated Sb/C nanohybrid as a SIB anode is also demonstrated, showing good electrochemical performance.

Poly(siloxane imide) Binder for Silicon-Based Lithium-Ion Battery Anodes via Rigidness/Softness Coupling.

Binders play a crucial role in maintaining mechanical integrity of electrodes in lithium-ion batteries. However, the conventional binders lack proper elasticity, and they are not suitable for high-performance silicon anodes featuring huge volume change during cycling. Herein, a poly(siloxane imide) copolymer (PSI) has been designed, synthesized, and utilized as a binder for silicon-based anodes. A rigidness/softness coupling mechanism is demonstrated by the PSI binder, which can accommodate volume expansion of the silicon anode upon lithiation. The electrochemical performance in terms of cyclic stability and rate capability can be effectively improved with the PSI binder as demonstrated by a silicon nanoparticle anode.

PEDOT:PSS for Flexible and Stretchable Electronics: Modifications, Strategies, and Applications.

Substantial effort has been devoted to both scientific and technological developments of wearable, flexible, semitransparent, and sensing electronics (e.g., organic/perovskite photovoltaics, organic thin-film transistors, and medical sensors) in the past decade. The key to realizing those functionalities is essentially the fabrication of conductive electrodes with desirable mechanical properties. Conductive polymers (CPs) of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) have emerged to be the most promising flexible electrode materials over rigid metallic oxides and play a critical role in these unprecedented devices as transparent electrodes, hole transport layers, interconnectors, electroactive layers, or motion-sensing conductors. Here, the current status of research on PEDOT:PSS is summarized including various approaches to boosting the electrical conductivity and mechanical compliance and stability, directly linked to the underlying mechanism of the performance enhancements. Along with the basic principles, the most cutting edge-progresses in devices with PEDOT:PSS are highlighted. Meanwhile, the advantages and plausible problems of the CPs and as-fabricated devices are pointed out. Finally, new perspectives are given for CP modifications and device fabrications. This work stresses the importance of developing CP films and reveals their critical role in the evolution of these next-generation devices featuring wearable, deformable, printable, ultrathin, and see-through characteristics.

Hierarchical Porous and Zinc-Ion-Crosslinked PIM-1 Nanocomposite as a CO2 Cycloaddition Catalyst with High Efficiency.

CO2 cycloaddition to epoxides is an effective and economical utilization method to alleviate the current excessive CO2 emission situation. The development of catalysts with both high catalytic efficiency and high recyclability is necessary but challenging. In this context, a heterogeneous catalyst was synthesized based on a zinc-ion-crosslinked polymer with intrinsic microporosity (PIM-1). The high microporosity of PIM-1 promoted a high Zn2+ loading rate. Additionally, the relatively stable ionic bond formed between Zn2+ and the PIM-1 framework through electrostatic interaction ensured high loading stability. In the process of CO2 cycloaddition with propylene epoxide, an optimized conversion of 90 % with a turnover frequency as high as 9533 h-1 could be achieved within 0.5 h at 100 °C and 2 MPa. After 15 cycles, the catalytic efficiency did not demonstrate a significant decline, and the catalyst was able to recover most of its activity after Zn2+ reloading. This work thereby provides a strategically designed CO2 conversion catalyst based on an ionic crosslinked polymer with intrinsic microporosity.

Endovascular Coiling Versus Microsurgical Clipping for Patients With Ruptured Very Small Intracranial Aneurysms: Management Strategies and Clinical Outcomes of 162 Cases.

BACKGROUND: Treatments for intracranial aneurysms mainly include endovascular treatment and craniotomy. Most studies report on large intracranial aneurysms, yet treatments for very small intracranial aneurysms remain controversial. Our purpose was to explore management strategies for ruptured very small intracranial aneurysms. METHODS: From January 2002 to September 2010, 162 consecutive patients with ruptured very small intracranial aneurysms (≤3 mm) were retrospectively analyzed by comparing procedural data, adverse events, additional procedures, and length of hospital stay between management strategies. Modified Rankin Scale was assessed at 2 months and at 1 year by a postal questionnaire and telephone interview. RESULTS: Of the 85 patients in the microsurgical group, 79 underwent surgical clipping and 6 underwent wrapping; 77 patients underwent endovascular therapy (endovascular group), including coiling (65 cases), stent-assisted (13 cases) and balloon-assisted (7 cases) coiling, and stenting (2 cases). At 2 months, a good grade (modified Rankin Scale 0-2) was achieved in 74% of patients in the endovascular group and 69.4% of patients in the microsurgical group. At 1 year, a good grade was achieved by 84.9% in the endovascular group and 80% in the microsurgical group. Logistic regression results showed that whichever treatment option was chosen, Hunt-Hess grade, age, cerebral vasospasm, and complications contributed significantly to the prediction of outcome at 2 months. CONCLUSIONS: Endovascular therapy for ruptured very small intracranial aneurysms was not inferior to surgical clipping and showed a slight trend toward better prognosis.