Chemical Strain of Graphite-Based Anode during Lithiation and Delithiation at Various Temperatures.

Electrochemical lithiation/delithiation of electrodes induces chemical strain cycling that causes fatigue and other harmful influences on lithium-ion batteries. In this work, a homemade in situ measurement device was used to characterize simultaneously chemical strain and nominal state of charge, especially residual chemical strain and residual nominal state of charge, in graphite-based electrodes at various temperatures. The measurements indicate that raising the testing temperature from 20°C to 60°C decreases the chemical strain at the same nominal state of charge during cycling, while residual chemical strain and residual nominal state of charge increase with the increase of temperature. Furthermore, a novel electrochemical-mechanical model is developed to evaluate quantitatively the chemical strain caused by a solid electrolyte interface (SEI) and the partial molar volume of Li in the SEI at different temperatures. The present study will definitely stimulate future investigations on the electro-chemo-mechanics coupling behaviors in lithium-ion batteries.

Partial sodiation induced laminate structure and high cycling stability of black phosphorous for sodium-ion batteries.

Black phosphorus (BP) is a promising anode material for sodium ion batteries (SIBs) due to its extremely high theoretical capacity. However, the large volume change and breaking of the layered structure result in rapid capacity decay during cycling. Herein, our in situ transmission electron microscopy (TEM) study reveals the highly anisotropic Na diffusion and the formation of alternating layered and amorphous lamellas in BP nanosheets with small volume expansion induced by partial sodiation. Inspired by these results, we investigate systematically the cyclability of BP at controlled discharge capacities using half-cell SIBs, expecting to achieve good cyclability by sacrificing some of the capacity and preserving the layered structure of BP. Our results show that the cycling stability of BP is obviously improved by controlling the capacity appropriately. When the discharge capacity is limited at 400 mA h g-1, the half-cell can sustain more than 100 cycles with an active material mass loading of ∼2 mg cm-2, which is at least 4 times longer than when the capacity is limited at 600 mA h g-1 or above. The in situ TEM and electrochemical tests indicate that maintaining the layered structure by controlling the capacity is key to improve the cyclability of BP as an anode in SIBs.

Minimally invasive spine surgery decreases postoperative pain and inflammation for patients with lumbar spinal stenosis.

In certain cases, lumbar spinal stenosis may lead to lumbar nervous disorder. A previous study indicated that minimally invasive spine surgery (MISS) presents benefits compared with conventional open surgery (COS). In the current study, the efficacy of MISS and COS for lumbar spinal stenosis patients was investigated. A total of 82 patients with lumbar spinal stenosis were enrolled and divided into two age-matched groups that received MISS (n=41) or COS (n=41). Patient parameters, including symptoms, inflammatory score, visual analog score (VAS), wound length, Oswestry Disability Index (ODI), hospital stay and postoperative outcomes were analyzed in the current study. Outcomes indicated that both MISS and COS significantly improved symptoms of lumbar spinal stenosis compared with the baseline. It was observed that MISS resulted in decreased wound length and hospital stay compared with COS for patients with lumbar spinal stenosis. The results revealed that MISS had better outcomes compared with COS in improving ODI and inflammatory score for patients with lumbar spinal stenosis. Notably, it was identified that MISS exhibited improved VAS for back and leg pain compared with the COS group for patients with lumbar spinal stenosis. In conclusion, these outcomes indicate that MISS was more effective compared with COS for improving symptoms in patients with lumbar stenosis.

Understanding of myofascial trigger points.

OBJECTIVE: To investigate the current practice of myofascial pain syndrome (MPS) including current epidemiology, pathology, diagnosis and treatment. DATA SOURCES: The data analyzed in this review were mainly from relevant articles without restriction on the publication date reported in PubMed, MedSci, Google scholar. The terms "myofasial trigger points" and "myofacial pain syndrome" were used for the literature search. STUDY SELECTION: Original articles with no limitation of research design and critical reviews containing data relevant to myofascial trigger points (MTrPs) and MPS were retrieved, reviewed, analyzed and summarized. RESULTS: Myofascial pain syndrome (MPS) is characterized by painful taut band, referred pain, and local response twitch with a prevalence of 85% to 95% of incidence. Several factors link to the etiology of MTrPs, such as the chronic injury and overload of muscles. Other factors, such as certain nutrient and hormone insufficiency, comorbidities, and muscle imbalance may also maintain the MTrP in an active status and induce recurrent pain. The current pathology is that an extra leakage acetylcholine at the neuromuscular junction induces persistent contracture knots, relative to some hypotheses of integration, muscle spindle discharges, spinal segment sensitization, ect. MTrPs can be diagnosed and localized based on a few subjective criteria. Several approaches, including both direct and supplementary treatments, can inactivate MTrPs. Direct treatments are categorized into invasive and conservative. CONCLUSION: This review provides a clear understanding of MTrP pain and introduces the most useful treatment approaches in China.

Value of ultrasonography for observation of early healing of humeral shaft fractures.

PURPOSE: Explore the value of ultrasonography for observation of early healing of humeral shaft fractures. METHODS: Sixty-five humeral shaft fracture patients were recruited. They were examined sonographically with color Doppler ultrasonography (CDU) and/or power Doppler ultrasonography (PDU) during the 1st week, 2nd week, 3rd week, 4th week, 9th week, and 15th week after the initial surgical procedure of internal fixation. Formation of callus consolidation and the resistance indexes (RI) of blood flow in different durations were compared between the good healing group and bad healing (delayed fracture healing or nonunion) group. RESULTS: Ultrasound showed that 59 patients had good fracture healing. Within the 2nd and 4th week after surgery, the RI decreased over time (P < 0.05) and color Doppler flow imaging (CDFI/PDU) grading ranged from II to III. Six patients had bad fracture healing (delayed healing or nonunion). Insufficient or absent blood flow signals demonstrated that no callus was found in and/or around the fracture sites. CDFI grading ranged from 0 to I. There was significant difference compared with the good healing group (P < 0.05). CONCLUSION: CDFI/PDU is an easy, painless, and effective method for predicting the prognosis of humeral shaft fractures by estimating early healing.

[Treatment of intra-articular calcaneal fractures by minimally invasive through the sinus tarsi approach and external fixation with calcaneal locking plates].

OBJECTIVE: To investigate the clinical results and the superiority of minimally invasive sinus tarsi approach andABSTRACT Objective :To investigate the clinical results and the superiority of minimally invasive sinus tarsi approach and external fixation with calcaneal locking plates for the treatment of the intra-articular calcaneal fracture. METHODS: From July 2011 to August 2012, 12 cases (13 feet) were treated by sinus tarsi approach and external fixation with calcaneal locking plates. There were 10 males and 2 females, aged from 25 to 48 years old (means 35 years old). According to Sanders classifi- cation system, there were 7 feet with type II, 6 feet with type III. The Böhler angle and Gissane angle were compared before and after operation. The clinical results were evaluated with the Maryland foot score system. RESULTS: All 12 cases were followed up from 6 to 14 months (means 10 months). There were no incision complications. Fracture healing time was from 3 to 6 months (means 4 months). The Böhler angle increased from preoperative (11.19 +/- 5.69) degrees to postoperative (30.13 +/- 7.52) degrees; The Gissane angle increased from preoperative (108.31 +/- 10.35) degrees to postoperative (118.99 +/- 8.94) degrees. According to Maryland foot score system, 8 feet got an excellent result, 3 good, 2 fair. CONCLUSION: Open reduction by sinus tarsi approach and external fixation with calcaneal locking plates is an effective method for treatment of Sanders II, III calcaneal fracture. It can obtain good reduction and stable fixation with minimal invasion and lower complications.