Phase 3 Safety and Immunogenicity Study of a Three-dose Series of Twenty-valent Pneumococcal Conjugate Vaccine in Healthy Infants and Toddlers.

BACKGROUND: Global pediatric immunization programs with pneumococcal conjugate vaccines (PCVs) have reduced vaccine-type pneumococcal disease, but a substantial disease burden of non-PCV serotypes remains. METHODS: This phase 3, randomized (1:1), double-blind study evaluated safety and immunogenicity of 20-valent PCV (PCV20) relative to 13-valent PCV (PCV13) in healthy infants. Participants received 2 infant doses and a toddler dose of PCV20 or PCV13, with diphtheria-tetanus-acellular pertussis combination vaccine at all doses and measles, mumps, rubella and varicella vaccines at the toddler dose. Primary pneumococcal immunogenicity objectives were to demonstrate noninferiority (NI) of PCV20 to PCV13 for immunoglobulin G geometric mean concentrations after infant and toddler doses and percentages of participants with predefined serotype-specific immunoglobulin G concentrations after infant doses. Safety endpoints included local reactions, systemic events and adverse events. RESULTS: Overall, 1204 participants were vaccinated (PCV20, n = 601; PCV13, n = 603). One month after the toddler dose, 19/20 serotypes met NI for immunoglobulin G geometric mean concentrations; serotype 6B narrowly missed NI [PCV20/PCV13 geometric mean ratio: 0.57 (2-sided 95% confidence interval: 0.48-0.67); NI criterion: lower 2-sided 95% confidence interval >0.5]. Sixteen/twenty serotypes met NI for ≥1 primary objective after 2 infant doses. PCV20 induced robust opsonophagocytic activity, and boosting responses were observed for all vaccine serotypes, including those missing statistical NI. The safety/tolerability profile of PCV20 was like that of PCV13. CONCLUSIONS: PCV20 3-dose series in infants was safe and elicited robust immune responses. Based on these results and PCV13 experience, PCV20 3-dose series is expected to be protective for all 20 vaccine serotypes. NCT04546425.

Safety and immunogenicity of a multivalent pneumococcal conjugate vaccine given with 13-valent pneumococcal conjugate vaccine in healthy infants: A phase 2 randomized trial.

Use of pneumococcal conjugate vaccines (PCVs) has led to substantial reductions in the global burden of pediatric pneumococcal disease. Expansion of serotype coverage has been achieved by increasing PCV valency, but this may carry the potential risk of antibody interference. A complementary 7-valent PCV (cPCV7) including polysaccharide conjugates from 7 non-13-valent (PCV13) serotypes was developed to potentially complement PCV13-mediated protection and expand serotype coverage. This study evaluated cPCV7 and PCV13 coadministered in separate limbs or separated in time in infants. This phase 2, multicenter, open-label study included 512 infants randomized 1:1:1 to receive cPCV7 coadministered with PCV13 at ages 2, 4, 6, and 12 months (cPCV7 Coadministered); cPCV7 given at ages 3, 5, 7, and 13 months, 3‒5 weeks after PCV13 (cPCV7 Separated); or PCV13 at ages 2, 4, 6, and 12 months followed by a single supplemental dose of cPCV7 at 13 months (PCV13 Control). Safety evaluations included local reactions, systemic events, and adverse events. Serotype-specific immunoglobulin G concentrations and opsonophagocytic activity titers were assessed. The safety profile of cPCV7 was similar to that of PCV13. cPCV7 was well-tolerated in infants when coadministered with or given separately from PCV13. Robust and functional immune responses for all cPCV7 serotypes were observed in both cPCV7 groups. No immunologic interference was observed for either the cPCV7 or PCV13 serotypes with coadministration. A single cPCV7 dose induced immune responses in toddlers. These findings support potential coadministration of a complementary PCV to supplement protection provided by existing PCVs.Trial registration: ClinicalTrials.gov, NCT03550313.

Comparison of pneumococcal immunogenicity elicited by the PCV13 and PCV15 vaccines in adults 18 through 49 years of age.

AIM: Pneumococcal conjugate vaccines (PCV13, PCV15, PCV20) effectively target the capsular polysaccharides of the most common disease-causing Streptococcus pneumoniae serotypes. In this short communication, we analyzed healthy participants who received PCV13 and PCV15 vaccines as part of a recently concluded exploratory clinical trial and report antibody responses to the 13 shared serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) as well as functional OPA responses to serotype 3. METHODS: Sera from 87 adult participants (18 through 49 years of age) randomized to receive either PCV13 or PCV15 were collected (n = 46 or n = 41, respectively), from 17 study centers in the US. IgG concentrations of the 13 shared serotypes and serotype 3-specific OPA titers were analyzed before and 1 month after vaccination using internally validated assays. RESULTS: At 1 month after vaccination, IgG GMCs of the 13 shared serotypes in PCV13 were similar to those for PCV15. Specifically, serotype 3 OPA GMTs and 95% CIs were similar 1 month after vaccination for PCV13 (62.9 [48.9, 80.9]) and PCV15 (71.1 [50.9, 99.2]). CONCLUSION: In healthy participants who received either PCV13 or PCV15, similar serotype-specific responses were observed between all shared serotypes when a uniform validated internal assay was used. Of note, data from this study suggest that both vaccines induce similar functional antibody responses against pneumococcal serotype 3.

Drug-Coated Balloons for Dysfunctional Dialysis Arteriovenous Fistulas.

BACKGROUND: Standard percutaneous transluminal angioplasty is the current recommended treatment for dysfunctional hemodialysis fistulas, yet long-term outcomes of this treatment are poor. Drug-coated balloons delivering the antirestenotic agent paclitaxel may improve outcomes. METHODS: In this prospective, single-blinded, 1:1 randomized trial, we enrolled 330 participants at 29 international sites. Patients with new or restenotic lesions in native upper-extremity arteriovenous fistulas were eligible for participation. After successful high-pressure percutaneous transluminal angioplasty, participants were randomly assigned to receive treatment with a drug-coated balloon or a standard balloon. The primary effectiveness end point was target-lesion primary patency, defined as freedom from clinically driven target-lesion revascularization or access-circuit thrombosis during the 6 months after the index procedure. The primary safety end point, serious adverse events involving the arteriovenous access circuit within 30 days, was assessed in a noninferiority analysis (margin of noninferiority, 7.5 percentage points). The primary analyses included all participants with available end-point data. Additional sensitivity analyses were performed to assess the effect of missing data. RESULTS: A total of 330 participants underwent randomization; 170 were assigned to receive treatment with a drug-coated balloon, and 160 were assigned to receive treatment with a standard balloon. During the 6 months after the index procedure, target-lesion primary patency was maintained more often in participants who had been treated with a drug-coated balloon than in those who had been treated with a standard balloon (82.2% [125 of 152] vs. 59.5% [88 of 148]; difference in risk, 22.8 percentage points; 95% confidence interval [CI], 12.8 to 32.8; P<0.001). Drug-coated balloons were noninferior to standard balloons with respect to the primary safety end point (4.2% [7 of 166] and 4.4% [7 of 158], respectively; difference in risk, -0.2 percentage points; 95% CI, -5.5 to 5.0; P = 0.002 for noninferiority). Sensitivity analyses confirmed the results of the primary analyses. CONCLUSIONS: Drug-coated balloon angioplasty was superior to standard angioplasty for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulas during the 6 months after the procedure and was noninferior with respect to access circuit-related serious adverse events within 30 days. (Funded by Medtronic; IN.PACT AV Access Study ClinicalTrials.gov number, NCT03041467.).

Pivotal results for the Valiant Navion stent graft system in the Valiant EVO global clinical trial.

OBJECTIVE: The Valiant Navion stent graft system (Medtronic, Santa Rosa, Calif) is a new iteration of a thoracic endograft for the treatment of descending thoracic aortic aneurysms. Herein, the 30-day primary safety and efficacy outcomes and secondary end points are presented. METHODS: The Valiant EVO global clinical trial is a prospective, nonrandomized, single-arm trial. Patient enrollment occurred from April 2016 to October 2017. The primary end point was defined as access and/or deployment failure and/or a major device effect (MDE), including device-related secondary procedures, device-related mortality, conversion to open surgery, or thoracic aortic aneurysm rupture within 30 days of the index procedure. Other measures of stent graft performance including procedural data, rates of secondary procedures, and frequency of endoleaks are also reported. RESULTS: Of the 87 consecutive patients undergoing thoracic endovascular aneurysm repair who were enrolled, 33 (37.9%) were female with 61 (70.9%) presenting with severe access artery tortuosity and 66 (85.7%) with high thoracic aortic tortuosity per core laboratory evaluation. The mean procedure duration was 88.7 ± 53.4 minutes and geographical differences existed such as percutaneous access (37/52 [71.2%]) in the United States and surgical cut down in the outside of the U.S. sites (28/35 [80.0%]). There were no access or deployment failures and only 2.3% of the patients (2/87; P < .0001; performance goal of 16%) experienced a MDE within 30 days of the index procedure. Two secondary procedures (n = 1 retrograde type A dissection; n = 1 aortic arch rupture) were required, and in the first 30 days, two patients died leading to a freedom from all-cause mortality of 97.7%. Endoleaks at 1 month were reported in 2.5% of patients (n = 1 type Ia; n = 1 type II). CONCLUSIONS: Access/deployment failures, MDEs, and endoleaks were rare in the first 30 days of the Valiant Evo clinical trial. The Valiant Navion thoracic stent graft system has shown encouraging 30-day results in this challenging cohort and trial patients will continue to be followed through 5 years.

Sex Differences in the Use of Oral Anticoagulants for Atrial Fibrillation: A Report From the National Cardiovascular Data Registry (NCDR®) PINNACLE Registry.

BACKGROUND: Despite higher thromboembolism risk, women with atrial fibrillation have lower oral anticoagulation (OAC) use compared to men. The influence of the CHA2DS2-VASc score or the introduction of non-vitamin K OACs on this relationship is not known. METHODS AND RESULTS: Using the PINNACLE National Cardiovascular Data Registry from 2008 to 2014, we compared the association of sex with OAC use (warfarin or non-vitamin K OACs) overall and by CHA2DS2-VASc score and examined temporal trends in OAC use by sex. Multivariable regression models assessed the association between sex and OAC use in those with CHA2DS2-VASc scores ≥2. Temporal analyses assessed changes in OAC use by sex over time. Of the 691 906 atrial fibrillation patients, 48.5% were women. Women were significantly less likely than men to use any OAC overall (56.7% versus 61.3%; P<0.001) and at all levels of CHA2DS2-VASc score (adjusted risk ratio 9% to 33% lower, all P<0.001). Compared to other thromboembolic risk factors, female sex was associated with lower use of OAC (risk ratio 0.90, 95%CI 0.90-0.91). Over time, non-vitamin K OAC use increased at a slightly higher rate in women (56.2% increase per year, 95%CI 54.6% to 57.9%) compared to men (53.6% increase per year, 95%CI 52.0% to 55.2%), yet women remained less likely to receive any OAC at all time points (P<0.001). CONCLUSIONS: Among patients with atrial fibrillation, women were significantly less likely to receive OAC at all levels of the CHA2DS2-VASc score. Despite increasing non-vitamin K OAC use, women had persistently lower rates of OAC use compared to men over time.

Contemporary Trends in Oral Anticoagulant Prescription in Atrial Fibrillation Patients at Low to Moderate Risk of Stroke After Guideline-Recommended Change in Use of the CHADS2 to the CHA2DS2-VASc Score for Thromboembolic Risk Assessment: Analysis From the National Cardiovascular Data Registry's Outpatient Practice Innovation and Clinical Excellence Atrial Fibrillation Registry.

BACKGROUND: Use of the CHA2DS2-VASc score instead of the CHADS2 score for thromboembolic risk stratification and initiation of oral anticoagulation (OAC) was recommended in the 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society atrial fibrillation (AF) guidelines. We sought to define the proportion of patients with AF qualifying for and receiving OAC in contemporary practice by applying the CHA2DS2-VASc score to patients with a low CHADS2 score. METHODS AND RESULTS: Among patients with AF enrolled in the American College of Cardiology National Cardiovascular Data Registry's outpatient Practice Innovation and Clinical Excellence registry (2008-2014) CHADS2 score of 0 or 1, we calculated the impact of adoption of the CHA2DS2-VASc score on the proportion of patients with an indication for OAC. We examined trends in prescription of OAC overall, direct OAC (dabigatran/rivaroxaban/apixaban), and multivariable associations between clinical characteristics and OAC use. Of 346 068 patients with AF aged 65±12 years, 61% were men and 65% were white. In total, 24% of those with CHADS2=0 and 81% of those with a CHADS2=1 were reclassified as having a definite indication for OAC (CHA2DS2-VASc score ≥2). OAC use increased from 37% to 48% during the study period, and direct OAC use increased from 5% to 30%. Increasing CHA2DS2-VASc score (odds ratio, 2.07; 95% confidence interval, 1.97-2.19 for score of 4 versus 0) and rhythm control strategy (odds ratio, 1.34; 95% confidence interval, 1.30-1.39) were associated with increased OAC use. CONCLUSIONS: Adoption of the CHA2DS2-VASc score reclassifies 64.5% of patients with AF with low CHADS2 scores into a class I indication for OAC prescription. Overall OAC prescription increased between 2011 and 2014.

Enteric Coating and Aspirin Nonresponsiveness in Patients With Type 2 Diabetes Mellitus.

BACKGROUND: A limitation of aspirin is that some patients, particularly those with diabetes, may not have an optimal antiplatelet effect. OBJECTIVES: The goal of this study was to determine if oral bioavailability mediates nonresponsiveness. METHODS: The rate and extent of serum thromboxane generation and aspirin pharmacokinetics were measured in 40 patients with diabetes in a randomized, single-blind, triple-crossover study. Patients were exposed to three 325-mg aspirin formulations: plain aspirin, PL2200 (a modified-release lipid-based aspirin), and a delayed-release enteric-coated (EC) aspirin. Onset of antiplatelet activity was determined by the rate and extent of inhibition of serum thromboxane B2 (TXB2) generation. Aspirin nonresponsiveness was defined as a level of residual serum TXB2 associated with elevated thrombotic risk (<99.0% inhibition or TXB2 >3.1 ng/ml) within 72 h after 3 daily aspirin doses. RESULTS: The rate of aspirin nonresponsiveness was 15.8%, 8.1%, and 52.8% for plain aspirin, PL2200, and EC aspirin, respectively (p < 0.001 for both comparisons vs. EC aspirin; p = 0.30 for comparison between plain aspirin and PL2200). Similarly, 56% of EC aspirin-treated subjects had serum TXB2 levels >3.1 ng/ml, compared with 18% and 11% of subjects after administration of plain aspirin and PL2200 (p < 0.0001). Compared with findings for plain aspirin and PL2200, this high rate of nonresponsiveness with EC aspirin was associated with lower exposure to acetylsalicylic acid (63% and 70% lower geometric mean maximum plasma concentration [Cmax] and 77% and 82% lower AUC0-t [area under the curve from time 0 to the last time measured]) and 66% and 72% lower maximum decrease of TXB2, with marked interindividual variability. CONCLUSIONS: A high proportion of patients treated with EC aspirin failed to achieve complete inhibition of TXB2 generation due to incomplete absorption. Reduced bioavailability may contribute to "aspirin resistance" in patients with diabetes. (Pharmacodynamic Evaluation of PL2200 Versus Enteric-Coated and Immediate Release Aspirin in Diabetic Patients; NCT01515657).

Cardiovascular Mortality in Patients With Type 2 Diabetes and Recent Acute Coronary Syndromes From the EXAMINE Trial.

OBJECTIVE: We evaluated the risk of cardiovascular (CV) death in all Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care (EXAMINE) study participants and in those who experienced an on-study, major nonfatal CV event. RESEARCH DESIGN AND METHODS: The study randomly assigned 5,380 patients with type 2 diabetes to alogliptin or placebo within 15 to 90 days of an acute coronary syndrome (ACS). Deaths and nonfatal CV events (myocardial infarction [MI], stroke, hospitalized heart failure [HHF], and hospitalization for unstable angina [UA]) were adjudicated. Patients were monitored until censoring or death, regardless of a prior postrandomized nonfatal CV event. Time-updated multivariable Cox models were used to estimate the risk of death in the absence of or after each nonfatal event. RESULTS: Rates of CV death were 4.1% for alogliptin and 4.9% for placebo (hazard ratio [HR] 0.85; 95% CI 0.66, 1.10). A total of 736 patients (13.7%) experienced a first nonfatal CV event (5.9% MI, 1.1% stroke, 3.0% HHF, and 3.8% UA). Compared with patients not experiencing a nonfatal event, the adjusted HR (95% CI) for death was 3.12 after MI (2.13, 4.58; P < 0.0001) 4.96 after HHF (3.29, 7.47; P < 0.0001), 3.08 after stroke (1.29, 7.37; P = 0.011), and 1.66 after UA (0.81, 3.37; P = 0.164). Mortality rates after a nonfatal event were comparable for alogliptin and placebo. CONCLUSIONS: In patients with type 2 diabetes and a recent ACS, the risk of CV death was higher after a postrandomization, nonfatal CV event, particularly heart failure, compared with those who did not experience a CV event. The risk of CV death was similar between alogliptin and placebo.

Variability in freedom from loss of primary patency results in trials assessing stent implantation in the superficial femoral artery.

BACKGROUND: Primary patency (PP) in trials assessing superficial femoral artery (SFA) stenting is defined as a combination of vessel patency assessed by duplex ultrasound (DUS) at the 12-month follow-up exam and freedom from revascularization of the index vessel through 12 months of follow-up. Loss of PP is thus more likely to be identified during the mandated DUS assessment. Moreover, DUS is performed within a prespecified allowed window of time for the visit that exceeds 12 months (typically by 30 days). Therefore, the time frame for detecting patency with DUS exceeds the time frame in which revascularization is captured. Survival analyses are often applied to present estimates of freedom from loss of PP, but there are no clear guidelines as to the correct method for presenting these analyses in reports from clinical trials. We aimed to analyze the implications of applying different methods in assessing freedom from loss of PP in studies assessing stenting for diseased SFA. METHODS: Data were simulated based on existing available results from SFA bare-metal nitinol stent trials published between 2009 and 2013 and summarized in a previous analysis (STROLL, SUPERB, RESILIENT, DURABILITY I, DURABILTY II, COMPLETE SFA). Six different approaches to Kaplan Meier (KM) analyses were applied based on entry criteria into and time frame of the KM model. RESULTS: Six KM estimates of PP were generated for each of the 10,000 simulated datasets. The average exact PP rate was 70.6%, while the average estimated KM rates using the six different methods ranged between 68.0% and 81.9%. CONCLUSION: KM estimates of PP vary substantially according to the methods employed. These may lead to misrepresentation of results from clinical trials. The development of a unified approach is advocated.

Variability of individual platelet reactivity over time in patients treated with clopidogrel: insights from the ELEVATE-TIMI 56 trial.

BACKGROUND: The degree of antiplatelet response to clopidogrel has been associated with clinical outcomes. Studies have investigated whether adjustment of antiplatelet therapies based on a single platelet function test is beneficial. OBJECTIVES: The aim of the study was to test the stability of platelet reactivity measurements over time among patients treated with standard and double doses of clopidogrel. METHODS: The ELEVATE-TIMI 56 (Escalating Clopidogrel by Involving a Genetic Strategy-Thrombolysis In Myocardial Infarction 56) investigators genotyped 333 patients with coronary artery disease and randomized them to various clopidogrel regimens. Patients with at least 2 platelet function results on the same maintenance dose of clopidogrel (75 mg or 150 mg) were analyzed. Platelet aggregation was measured using P2Y12 reaction units (PRU). RESULTS: In total, the mean platelet reactivity and the total number of nonresponders (PRU ≥230) with clopidogrel did not change between 2 periods for the 75-mg (22.4% vs. 21.9%; p = 0.86) and 150-mg doses of clopidogrel (11.5% vs. 11.5%; p = 1.00). In contrast, when evaluating each patient individually, 15.7% of patients taking clopidogrel 75 mg and 11.4% of patients taking 150 mg had a change in their responder status when tested at 2 different time points (p < 0.001). Despite being treated with the same dose of clopidogrel, >40% of patients had a change in PRU >40 on serial sampling, which approximates the average PRU difference caused by increasing the clopidogrel dose from 75 mg to 150 mg. CONCLUSIONS: Measurements of platelet reactivity vary over time in a significant proportion of patients. Thus, treatment adjustment according to platelet function testing at a single time point might not be sufficient for guiding antiplatelet therapy in clinical or research settings. (Escalating Clopidogrel by Involving a Genetic Strategy-Thrombolysis In Myocardial Infarction 56 [ELEVATE-TIMI 56]; NCT01235351).

Risk assessment to predict arterial and venous events in patients undergoing percutaneous coronary intervention.

Atherosclerosis and venous thromboembolism (VTE) share common risk factors. We set to assess the strength of the association between atherosclerosis risk factors and disease manifestation, and VTE, in patients with coronary artery disease undergoing percutaneous coronary intervention. We pooled data from 6 global randomized controlled trials assessing coronary stenting (ENDEAVOR and SIRIUS programs), developed separate risk scores to predict major adverse cardiac and cerebrovascular events (MACCEs: cardiac death, myocardial infarction, and stroke) and VTE, and compared their performance. The 5-year rates of MACCE and VTE were 10.8% and 2.04%, respectively. Selected predictors for MACCE performed equally well in predicting VTE (area under the receiver-operating characteristic curve [AUC] 0.651 vs 0.672), and selected predictors for VTE performed equally well in predicting MACCE (AUC 0.699 vs 0.620). Ejection fraction and age were associated with both MACCE and VTE. These findings support the concept of overlapping pathophysiology of VTE and atherothrombosis.

Introducing a 2-His-1-Glu nonheme iron center into myoglobin confers nitric oxide reductase activity.

A conserved 2-His-1-Glu metal center, as found in natural nonheme iron-containing enzymes, was engineered into sperm whale myoglobin by replacing Leu29 and Phe43 with Glu and His, respectively (swMb L29E, F43H, H64, called Fe(B)Mb(-His)). A high resolution (1.65 A) crystal structure of Cu(II)-CN(-)-Fe(B)Mb(-His) was determined, demonstrating that the unique 2-His-1-Glu metal center was successfully created within swMb. The Fe(B)Mb(-His) can bind Cu, Fe, or Zn ions, with both Cu(I)-Fe(B)Mb(-His) and Fe(II)-Fe(B)Mb(-His) exhibiting nitric oxide reductase (NOR) activities. Cu dependent NOR activity was significantly higher than that of Fe in the same metal binding site. EPR studies showed that the reduction of NO to N(2)O catalyzed by these two enzymes resulted in different intermediates; a five-coordinate heme-NO species was observed for Cu(I)-Fe(B)Mb(-His) due to the cleavage of the proximal heme Fe-His bond, while Fe(II)-Fe(B)Mb(-His) remained six-coordinate. Therefore, both the metal ligand, Glu29, and the metal itself, Cu or Fe, play crucial roles in NOR activity. This study presents a novel protein model of NOR and provides insights into a newly discovered member of the NOR family, gNOR.

Rational design of a structural and functional nitric oxide reductase.

Protein design provides a rigorous test of our knowledge about proteins and allows the creation of novel enzymes for biotechnological applications. Whereas progress has been made in designing proteins that mimic native proteins structurally, it is more difficult to design functional proteins. In comparison to recent successes in designing non-metalloproteins, it is even more challenging to rationally design metalloproteins that reproduce both the structure and function of native metalloenzymes. This is because protein metal-binding sites are much more varied than non-metal-containing sites, in terms of different metal ion oxidation states, preferred geometry and metal ion ligand donor sets. Because of their variability, it has been difficult to predict metal-binding site properties in silico, as many of the parameters, such as force fields, are ill-defined. Therefore, the successful design of a structural and functional metalloprotein would greatly advance the field of protein design and our understanding of enzymes. Here we report a successful, rational design of a structural and functional model of a metalloprotein, nitric oxide reductase (NOR), by introducing three histidines and one glutamate, predicted as ligands in the active site of NOR, into the distal pocket of myoglobin. A crystal structure of the designed protein confirms that the minimized computer model contains a haem/non-haem Fe(B) centre that is remarkably similar to that in the crystal structure. This designed protein also exhibits NO reduction activity, and so models both the structure and function of NOR, offering insight that the active site glutamate is required for both iron binding and activity. These results show that structural and functional metalloproteins can be rationally designed in silico.

Necklace-like hollow carbon nanospheres from the pentagon-including reactants: synthesis and electrochemical properties.

Necklace-like hollow carbon nanospheres (CNSs) have been successfully synthesized from the pentagon-including reactants, which provide an auxiliary example for the theoretical prediction that necklace-like hollow CNSs are assumed to be composed of the regular occurrence of nonhexagonal rings at the atomic level. Benefits of the as-obtained hollow CNSs also arise from the high Brunauer-Emmett-Teller value of 594.32 m(2)/g and a narrow pore distribution at 5 nm. The electrochemical hydrogen storage experiments for the as-obtained necklace-like hollow CNSs exhibit a capacity of 242 mAh/g at the current density of 200 mA/g, corresponding to a hydrogen storage of 0.89 wt %, which is higher than the previously reported electrochemical capacities for the multiwalled carbon nanotubes (MWCNTs). Furthermore, the as-obtained necklace-like hollow CNSs show a lithium capacity advantage compared with the carbon solid particles for application in lithium batteries. These results indicate that the necklace-like hollow CNSs provide a new candidate for the application in hydrogen storage and lithium batteries.