ABSTRACT
The high-capacity advantage of lithium metal anode was compromised by common use of copper as the collector. Furthermore, lithium pulverization associated with "dead" Li accumulation and electrode cracking deteriorates the long-term cyclability of lithium metal batteries, especially under realistic test conditions. Here, we report an ultralight, integrated anode of polyimide-Ag/Li with dual anti-pulverization functionality. The silver layer was initially chemically bonded to the polyimide surface and then spontaneously diffused in Li solid solution and self-evolved into a fully lithiophilic Li-Ag phase, mitigating dendrites growth or dead Li. Further, the strong van der Waals interaction between the bottommost Li-Ag and polyimide affords electrode structural integrity and electrical continuity, thus circumventing electrode pulverization. Compared to the cutting-edge anode-free cells, the batteries pairing LiNi0.8Mn0.1Co0.1O2 with polyimide-Ag/Li afford a nearly 10% increase in specific energy, with safer characteristics and better cycling stability under realistic conditions of 1× excess Li and high areal-loading cathode (4 milliampere hour per square centimeter).
ABSTRACT
Solid-state lithium-sulfur batteries have shown prospects as safe, high-energy electrochemical storage technology for powering regional electrified transportation. Owing to limited ion mobility in crystalline polymer electrolytes, the battery is incapable of operating at subzero temperature. Addition of liquid plasticizer into the polymer electrolyte improves the Li-ion conductivity yet sacrifices the mechanical strength and interfacial stability with both electrodes. In this work, we showed that by introducing a spherical hyperbranched solid polymer plasticizer into a Li+ -conductive linear polymer matrix, an integrated dynamic cross-linked polymer network was built to maintain fully amorphous in a wide temperature range down to subzero. A quasi-solid polymer electrolyte with a solid mass content >90 % was prepared from the cross-linked polymer network, and demonstrated fast Li+ conduction at a low temperature, high mechanical strength, and stable interfacial chemistry. As a result, solid-state lithium-sulfur batteries employing the new electrolyte delivered high reversible capacity and long cycle life at 25 °C, 0 °C and -10 °C to serve energy storage at complex environmental conditions.
ABSTRACT
The uncontrollable dendrite growth and unstable solid electrolyte interphase have long plagued the practical application of Li metal batteries. Herein, a dual-layered artificial interphase LiF/LiBO-Ag is demonstrated that is simultaneously reconfigured via an electrochemical process to stabilize the lithium anode. This dual-layered interphase consists of a heterogeneous LiF/LiBO glassy top layer with ultrafast Li-ion conductivity and lithiophilic Li-Ag alloy bottom layer, which synergistically regulates the dendrite-free Li deposition, even at high current densities. As a result, Li||Li symmetric cells with LiF/LiBO-Ag interphase achieve an ultralong lifespan (4500 h) at an ultrahigh current density and area capacity (20 mA cm-2 , 20 mAh cm-2 ). LiF/LiBO-Ag@Li anodes are successfully applied in quasi-solid-state batteries, showing excellent cycling performances in symmetric cells (8 mA cm-2 , 8 mAh cm-2 , 5000 h) and full cells. Furthermore, a practical quasi-solid-state pouch cell coupling with a high-nickel cathode exhibits stable cycling with a capacity retention of over 91% after 60 cycles at 0.5 C, which is comparable or even better than that in liquid-state pouch cells. Additionally, a high-energy-density quasi-solid-state pouch cell (10.75 Ah, 448.7 Wh kg-1 ) is successfully accomplished. This well-orchestrated interphase design provides new guidance in engineering highly stable interphase toward practical high-energy-density lithium metal batteries.
ABSTRACT
In Li-ion batteries, functional cosolvents could significantly improve the specific performance of the electrolyte, for example, the flame retardancy. In case the cosolvent shows strong Li+-coordinating ability, it could adversely influence the electrochemical Li+-intercalation reaction of the electrode. In this work, a noncoordinating functional cosolvent was proposed to enrich the functionality of the electrolyte while avoiding interference with the Li storage process. Hexafluorocyclotriphosphazene, an efficient flame-retardant agent with proper physicochemical properties, was chosen as a cosolvent for preparing functional electrolytes. The nonpolar phosphazene molecules with low electron-donating ability do not coordinate with Li+ and thus are excluded from the primary solvation sheath. In graphite-anode-based Li-ion batteries, the phosphazene molecules do not cointercalate with Li+ into the graphite lattice during the charging process, which helps to maintain integral anode structure and interface and contributes to stable cycling. The noncoordinating cosolvent was also applied to other types of electrode materials and batteries, paving a new way for high-performance electrochemical energy storage systems with customizable functions.
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BACKGROUND: It is controversial whether angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARB) have a potentially beneficial role in the respiratory system. This study investigated the association between ACEI/ARB medications and respiratory-related mortality in hypertensive patients in a real-world nationally representative cohort. METHODS: This was a retrospective analysis based on a prospective cohort study. A total of 10,530 patients with hypertension aged ≥ 20 years were included. The data was extracted from the US National Health and Nutrition Examination Survey during 1988-1994 and 1999-2006. The study was approved by the Institutional Review Boards. Moreover, inform concent was taken form all the participants. RESULTS: Overall, 27.7% (n = 2920) patients took ACEI/ARB agents. During a median follow-up of 12.4 years, 278 individuals died of respiratory disease, including chronic lower respiratory disease (n = 155) and inï¬uenza or pneumonia (n = 123). Compared with the patients without ACEI/ARB use, those taking ACEI/ARB were not associated with respiratory-specific mortality in a multivariable-adjusted Cox model. After 1: 1 matching, taking ACEI/ARB was also not related to respiratory mortality (Hazard ratio (HR) = 1.07, 95% CI: 0.79-1.43), inï¬uenza- or pneumonia-related (HR = 1.00, 95% CI: 0.65-1.54) and chronic pulmonary mortality (HR = 1.13, 95% CI: 0.75-1.69). After separating ACEI and ARB from anti-hypertensive medications, those associations remained unchanged. CONCLUSIONS: We discovered no significant link between ACEI or ARB medication and pulmonary-related mortality in hypertensive patients. In hypertensive patients, standard ACEI/ARB administration may have little effect on the respiratory system.
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<p><b>OBJECTIVE</b>To compare the advantages and disadvantages of unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion in treating single segmental lower lumbar vertebra diseases.</p><p><b>METHODS</b>Sixty-two patients with single segmental lower lumbar vertebra disease who received treatment between January 2008 and June 2009. These patients were consisted of 16 males and 46 females, ranging in age from 27 to 72 years old, with a mean age of 51.6 years old. Among these patients, lumbar degenerative disease had in 22 patients, recurrence of lumbar intervertebral disc protrusion in 13 patients, lumbar intervertebral disc protrusion accompany with spinal canal stenosis in 12 patients, massive lumbar intervertebral disc protrusion in 5 patients and lumbar degenerative spondylolisthesis with degree I in 10 patients. The lesions occurred at L3,4 segment in 5 patients, at L4,5 segment in 42 patients, and at L5S1 segment in 15 patients. Thirty patients underwent unilateral pedicle screw fixation (unilateral screw fixation group, group A) and thirty-two patients received unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation (bilateral screw fixation group, group B). Lumbar interbody fusion with intervertebral cages was also performed in all patients. Incision length, operation time, intraoperative blood loss and postoperative wound drainage were compared between two groups. Loosening or breakage of internal fixations, displacement of intervertebral cages and interbody fusion conditions were observed in each group. Preoperative and postoperative intervertebral height, coronal and sagittal Cobb angle and wound pain at 72 h after operation were compared between two groups. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the cinical effects.</p><p><b>RESULTS</b>Neither wound infection, skin necrosis, nerve root or cauda equia injury, nor worsened neurological dysfunction in the lower limb occurred in each group. There were no significant differences in incision length, intraoperative blood loss and postoperative wound drainage between two groups. The operation time in group A was significantly shorter than that of group B (P < 0.05). There were no significant differences in visual analogue scale value of the wound pain at postoperative 72 h between two groups (P > 0.05). All patients were followed up for 12-48 months,with a mean of 27.5 months. The intervertebral height of all patients had obviously recovered at 5 days after operation, furthermore, at the final follow-up, it still had well maintained. During follow-up, no pedicle screw and/or translaminar facet screw loosening, displacement or breakage and displacement of intervertebral cages were found. The lumbar interbody fusion rate was 96.7% and 96.9% in group A and group B, respectively, and there was no significant difference between two groups (P > 0.05). JOA score of all patients got obviously improved after operation (P < 0.05) and there was no significant difference between two groups (P > 0.05).</p><p><b>CONCLUSION</b>Both unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion have advantages of small incision, minimal invasion, simple operation, reliable stability, high interbody fusion rate,rapid recovery, encouraging clinical effects and less complications. Compared with unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation, the operation of unilateral pedicle screw fixation is simpler and can avoid using special equipments. Therefore, unilateral pedicle screw fixation plus lumbar interbody fusion can be used in treating single-segmental lower lumbar vertebra diseases under the precondition of strictly grasping indications for surgery and improving surgical skills.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Bone Screws , Lumbar Vertebrae , General Surgery , Spinal Diseases , General Surgery , Spinal Fusion , MethodsABSTRACT
<p><b>OBJECTIVE</b>To compare the effects of the treatment for the distal clavicle fracture with two different methods.</p><p><b>METHODS</b>There were 120 cases of the distal clavicle fractures involved in the study. Among them, 75 cases were treated by self-improved elastic band inclined "8" fixation (Manipulation group), 45 cases were treated by open reduction and internal fixation with clavicular hook plate (Operation group).</p><p><b>RESULTS</b>There was statistically significant difference between manipulation group (6.71+/-2.35 weeks) and operation group (11.38+/-4.58 weeks) in the time of fracture union (P<0.01); but, there was no statistically significant difference between manipulation group (100%) and operation group (97.8%) in the rate of fracture union (P>0.05). According to the evaluation of shoulder-joint function, 56, 14 and 5 cases obtained excellent, good and bad result respectively in manipulation group; 38, 5 and 2 cases obtained excellent, good and bad respectively in operation group. There was no statistically significant difference between manipulation group (93.3%) and operation group (95.5%) in the rate of excellent and good (P>0.05).</p><p><b>CONCLUSION</b>Compared with open reduction and internal fixation with clavicular hook plate, treatment with self-improved elastic band inclined "8" fixation can shorten the union time of fracture and reduce therapeutic risks, so it is an economical, practical and safe method for the distal clavicle fracture.</p>
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Case-Control Studies , Clavicle , Wounds and Injuries , Fracture Fixation, Internal , Methods , Fractures, Bone , Therapeutics , Manipulation, Orthopedic , MethodsABSTRACT
<p><b>OBJECTIVE</b>To observe dystrophin and utrophin expression in muscle tissues of Duchenne muscular dystrophy (DMD) mouse model (dko mouse) after having been treated with bone marrow mesenchymal stem cells (MSC) transplantation.</p><p><b>METHODS</b>The fifth generation of MSCs, cultured in vitro, was transplanted into dko mice by tail vein. The fluorescent expression of dystrophin and utrophin in gastrocnemius muscle tissue of dko mouse was detected and the average optical density of positive fibers was calculated.</p><p><b>RESULTS</b>MSCs that had been cultured for three generations had good homogeneousness and the immunological reaction after vein transplantation was low. There was an increasing tendency of dystrophin and utrophin fluorescent expression in sarcolemma of dko mouse within 5-20 weeks. Significant difference existed in fluorescent average optical density of positive fibers fifteen weeks before and after cell transplantation.</p><p><b>CONCLUSIONS</b>MSC has strong plasticity both in vitro and in vivo. MSC has a trend to reach the injured muscle tissues and turn into muscle fibers, which express dystrophin and utrophin. There is some plerosis function for myatrophy of dko mouse by MSC transplantation.</p>
