Predictors of 1- and 12-month mortality in bifurcation coronary intervention: a contemporary perspective.

Aim: Bifurcation-PCI is performed frequently, although without extensive evidence to back up a definitive solution for its complexity. We set out to identify factors associated with 1- and 12-month mortality after bifurcation-PCI between 2017 and 2021 in our tertiary center in Wales, UK. Results: Of 732 bifurcation PCI cases (mean age 69; 25% female), 67% were in ACS, 42% were left main PCI and 25.3% involved two-stent strategy. 30-day and 12-month mortality were 1.9 and 8.2%, respectively. Age, diabetes, smoking and renal failure are associated with mortality after bifurcation-PCI, while the choice between provisional and 2-stent strategies did not impact mortality/TLR. Conclusion: Awareness of 'real-world' outcomes of bifurcation-PCI should be used for appropriate patient selection, technique planning and procedural consent.

Use of aortic wall patches as leaflet replacement material during aortic valve repair.

Objectives: Aortic valve repair can be limited by inadequate leaflet tissue for proper coaptation. Various kinds of pericardium have been used for cusp augmentation, but most have failed because of tissue degeneration. A more durable leaflet substitute is needed. Methods: In this report, 8 consecutive cases are presented in which autologous ascending aortic tissue was used to augment inadequate native cusps during aortic valve repair. Biologically, aortic wall is a living autologous tissue that could have exceptional durability as a leaflet substitute. Techniques for insertion are described in detail, along with procedural videos. Results: Early surgical outcomes were excellent, with no operative mortalities or complications, and all valves were competent with low valve gradients. Patient follow-up and echocardiograms to a maximum of 8 months' postrepair remain excellent. Conclusions: Because of superior biologic characteristics, aortic wall has the potential to provide a better leaflet substitute during aortic valve repair and to expand patient categories amenable to autologous reconstruction. More experience and follow-up should be generated.

Comparison of Outcomes and Discharge Location After Transcatheter vs. Surgical Aortic Valve Replacement With Prior Coronary Artery Bypass Grafting.

Background: Published trials have shown that transcatheter aortic valve replacement (TAVR) is a safe alternative to surgical aortic valve replacement (SAVR) after prior coronary artery bypass grafting (CABG). However, differences in morbidity and discharge location between the 2 procedures are less thoroughly characterized. Methods: From January 1, 2006 to January 7, 2020, 1059 patients with severe aortic stenosis after CABG underwent either SAVR (n = 315/30%), transfemoral TAVR (TF-TAVR) (n = 575/54%), or alternative access TAVR (n = 169/16%) at a single, tertiary care, academic institution. Propensity-weighted matching was used to compare morbidity, mortality, length of postprocedure stay, and nonhome discharge between TF-TAVR (effective n = 163) and SAVR (effective n = 163) groups. Results: Among propensity-weighted groups, the TF-TAVR group experienced fewer transfusions than the SAVR group (effective n = 16 [9.5%] vs. 132 [81%]; p < 0 .0001), less new-onset atrial fibrillation (effective n = 5.1 [3.1%] vs. 43 [27%]; p = 0.009), and less prolonged mechanical ventilation >24 â€‹hours (effective n = 0.41 [0.25%] vs. 30 [18%]; p <0.0001). Permanent pacemaker implant was 9.3% (effective n = 13) after TF-TAVR vs. 5.5% (effective n = 7.9; p = 0.2) after SAVR, stroke 0.41% (effective n = 0.67) vs. 2.1% (effective n = 3.5; p = 0.2), and operative mortality 0.5% (effective n = 0.8) vs. 1.7% (effective n = 2.8; p = 0.8). The TF-TAVR group had shorter postprocedure lengths of stay (2.0 vs. 7.6 days; p < 0.0001). Discharge home was more common after TF-TAVR than SAVR (effective n = 156 [95%] vs. 118 [73%]; p = 0.01). Conclusions: For patients developing severe aortic stenosis after CABG, TF-TAVR rather than SAVR should be strongly considered because of lower morbidity, shorter length of stay, and greater likelihood of home discharge.

Predicting Gastrostomy Tube Placement After Intracerebral Hemorrhage: External Validation of the GRAVo Score.

BACKGROUND: Dysphagia is a common consequence of intracerebral hemorrhages (ICH). It can lead to enduring impairments of dietary intake and the requirement for feeding via percutaneous gastrostomy (PEG) tubes. However, variabilities in the course of swallowing recovery after ICH make it difficult to anticipate the need for PEG placement in an individual patient. A new tool called the GRAVo score was recently developed to predict PEG tube placement after an ICH but has not been externally validated. Our study aims were to externally validate the GRAVo score in a multicenter cohort and reexamine the role of race in predicting PEG placement, given the uncertain biological plausibility for this relationship observed in the derivation cohort. METHODS: Patients for this analysis were selected from a previously completed multicenter, randomized, double-blind futility design clinical trial, the Intracerebral Hemorrhage Deferoxamine trial, and underwent a retrospective review of prospectively collected data. The GRAVo scores were computed by using previously established methods using the following variables: Glasgow Coma Scale ≤ 12 (2 points), race (1 point for Black), age > 50 years (2 points), and ICH volume > 30 mL (1 point). Association of GRAVo scores with PEG placement were examined by using logistic regression analysis after adjustment for exposure to deferoxamine. Model performance was estimated by using area under the receiving operating characteristic curve (AUROC). Subsequently, a second model was created by excluding scores for race, and the AUROC of both models were compared. RESULTS: A total of 291 patients with complete data points served as the study cohort; 38 (13%) underwent PEG placement. The median GRAVo score for patients in the PEG and non-PEG groups were 4 (interquartile range 3-4) versus 2 (interquartile range 2-3), respectively (p < 0.0001). External validation of the GRAVo score yielded an AUROC of 0.7008 (95% confidence interval 0.6036-0.78); the model obtained without assignment of scores for the variable race yielded an AUROC of 0.6958 (95% confidence interval 0.6124-0.7891). The receiver operating characteristic curves from both models demonstrated close overlap. CONCLUSIONS: The results of our external validation demonstrate the validity of GRAVo scores for predicting PEG tube placement after an ICH. However, its performance was more modest compared with that of the derivation cohort. Inclusion of the race variable had no measurable effect on model performance. Differences in patient characteristics between these cohorts may have influenced our results. These findings should be taken into consideration when using the GRAVo score to assist clinical decision making on PEG placement after an ICH.

A Comparative Evaluation of Marginal Accuracy of Co-Cr Metal Copings Fabricated Using Traditional Casting Techniques and Metal Laser Sintering.

AIMS AND OBJECTIVES: The aim and objective of the study were to determine the amount of marginal discrepancy produced by cobalt-chromium (Co-Cr) copings fabricated using two different fabrication methods, i.e., traditional casting and direct metal laser-sintering (DMLS), and compare the values obtained between each fabrication technique and to evaluate if the fabrication technique can produce prosthesis that is within the standards of clinical acceptance of marginal discrepancy. MATERIALS AND METHODS: Twenty metal copings each were fabricated by laser sintering and traditional casting method. The marginal gap at the buccal, lingual, mesial, and distal areas was measured using the silicone replica technique. The stereomicroscope and optical microscope were used to measure the marginal discrepancy between the working die and the copings. Statistical analysis was done using a t-test using Open-epi calculator software. RESULTS: The values indicate that the marginal gap was less for the copings fabricated using Co-Cr alloy crowns that were fabricated with direct metal laser-sintered technique than Co-Cr alloy crowns fabricated with conventional casting technique. HOW TO CITE THIS ARTICLE: Gautam N, Khajuria RR, Ahmed R, et al. A Comparative Evaluation of Marginal Accuracy of Co-Cr Metal Copings Fabricated Using Traditional Casting Techniques and Metal Laser Sintering. Int J Clin Pediatr Dent 2021;14(1):128-132.

Outcomes after resection of primary cardiac sarcoma.

Objective: To evaluate the outcomes of surgical resection of malignant primary cardiovascular tumors. Methods: From 1983 to 2018, 32 patients underwent surgical resection of malignant primary cardiovascular sarcoma at Cleveland Clinic. Mean age was 48 ± 15 years, and 19 (59%) were women. Outcomes are compared between those with complete resection and those without, and in relation to primary location. Results: The most common histologic subtypes were angiosarcoma (n = 8 [25%]) and high-grade undifferentiated sarcoma (n = 7 [22%]). Fourteen (44%) involved the left heart, 9 (28%) the right heart, 8 (25%) the pulmonary arteries, and 1 (3%) the aorta. There was clinical evidence of isolated extracardiac metastases in 8 (25%). Six (19%) patients were deemed unresectable at surgery, undergoing biopsy and palliative debulking followed by referral for definitive chemotherapy and/or radiation. The remaining 26 (81%) patients underwent 31 tumor resections with curative intent. Seven (22%) patients had previously undergone a resection or biopsy at another institution. There were 10 second-time resections, 2 third-time resections, 1 fourth-time resection, and no operative mortalities. Median survival was 3 years, with estimated survival at 6 months and 1, 5, and 10 years of 90%, 73%, 31%, and 17%, respectively. Of the 8 (25%) who were considered disease-free following surgery, 4 experienced recurrences during follow-up. Conclusions: Primary cardiac sarcoma continues to be a challenging disease with poor prognosis. Aggressive resection with curative intent, frequent surveillance for local and distant recurrence, and systemic and local multimodality treatment optimizes outcomes.

Early Outcomes for In Situ Pericardial Roll Repair for Distant Anomalous Pulmonary Venous Return.

BACKGROUND: Repair of anomalous pulmonary venous return (APVR) when veins are remote from the left atrium (LA) is challenging and may eventuate in a higher prevalence of pulmonary vein stenosis, superior vena cava stenosis, or intracardiac baffle obstruction. We describe our experience in 6 patients with a technique, using both anterior and posterior in situ pericardial roll repairs, which reduces these complications. METHODS: Six patients underwent in situ pericardial roll repair of APVR at Cleveland Clinic between 2018 and 2019. Median age was 40 years (range, 0.25-65 years). Three patients had partial APVR of right upper and middle veins into superior vena cava high above the right pulmonary artery without atrial septal defect; 2 had scimitar syndrome, and the infant had heterotaxy with unbalanced atrioventricular canal and mixed obstructed total APVR. The anomalous pulmonary vein drained into the respective cava far from the LA, which was not ideal for traditional repair techniques. In situ pericardial roll directed anomalous pulmonary vein to the LA. Most patients had concomitant complex cardiac procedures. RESULTS: There was no mortality. Median hospital stay was 23 days (range, 4-60 days) and median follow-up was 20 months (range, 1-36 months). The infant required percutaneous dilatation and stenting of LA anastomosis but since underwent ventricular switch. At last follow-up, pulmonary veins were unobstructed and adult patients were asymptomatic with excellent functional status. CONCLUSIONS: In situ autologous pericardial roll is a useful technique that abrogates the need for mobilization of distant anomalous pulmonary vein with direct anastomosis or complex intracardiac baffles. It is suitable for multiple anatomic configurations and can be used in infants and adults.

A Vexing Recurrent Pericardial Effusion Without Underlying Pathology - Subsequent Diagnosis Of Lymphoma Proves A Rare First Presentation.

An elderly man had recurrent admissions with large symptomatic pericardial effusions. Initial computed tomography (CT) of thorax, abdomen and pelvis and pericardial fluid analysis did not reveal underlying cause. On subsequent presentation, pericardial window was formed but repeat pericardial fluid analysis and biopsy failed to give a diagnosis again. He then presented approximately after four months with worsening symptoms of dyspnoea and weight loss. General physical examination at that point noted inguinal lymphadenopathy. Repeat imaging with CT and magnetic resonance imaging (MRI) showed features of metastatic malignancy. Tissue diagnosis from inguinal lymph nodes proved to be diffuse large B-cell lymphoma (DLBCL).

Ischemic Stroke and Intracranial Hemorrhages During Impella Cardiac Support.

Impella is a percutaneously placed, ventricular assist device for short-term cardiac support. We aimed to study acute neurologic complications during short-term cardiac support with Impella. We reviewed prospectively collected data of 79 consecutive persons implanted with Impella at a single tertiary center. Acute neurologic events (ANE) were defined as ischemic strokes or intracranial hemorrhages. Among those with ANE, specific causes of ischemic and hemorrhagic events were collected and discussed. Of 79 persons with Impella with median 8 days of support (range 1-33 days), six (7.5%) developed ANE at a median of 5 days from implant (range 1-8 days). There were three ischemic strokes, two intracerebral hemorrhages, and one subdural hematoma. Hemorrhagic events were attributed to anticoagulant use and thrombocytopenia at the time of the events. Two ischemic strokes were attributed to inadequate anticoagulation with one case of pump thrombosis diagnosed at the time of ischemic stroke. Only two of the six patients survived the acute cardiogenic shock period to achieve heart transplantation. In-hospital ischemic strokes and intracranial hemorrhages are not uncommon during short-term cardiac support period with Impella. Antithrombotic intensity, duration of device support time, and thrombocytopenia might contribute to the incidence of these events.

Case Report: Ramipril and microscopic colitis; a necessary tool of cardiologists can rarely be devastating for patients.

Angiotensin converting enzyme inhibitors could lead to severe diarrhoea related to microscopic colitis. Few of such cases have been reported before and this serious problem, from a widely used class of drugs in hypertension and heart failure, needs to be more recognised. We describe the case of collagenous colitis related to ramipril use in the following case report. A 74-year-old farmer who had a history of triple vessel coronary artery disease was admitted to district general hospital with non-ST elevation myocardial infarction. He had known alcohol-related chronic pancreatitis with chronic diarrhoea as a complication, which was managed with pancreatic enzyme replacement therapy. However, he developed severe worsening of diarrhoea causing bowel incontinence and nocturnal symptoms during his admission to hospital. The explosive and watery nature of diarrhoea with urgency was so troublesome that it delayed coronary revascularisation and lead him to have significant psychological distress and low mood while nocturnal bowel motions meant he was unable to sleep. He was compliant with his pancreatic enzyme replacement therapy during this period. Infective causes were ruled out by stool microbiology examination and coeliac disease by oesophagogastroscopy and biopsy. It was noticed that he was recently prescribed ramipril that was later stopped as a possible diarrhoea trigger. Diarrhoea started settling immediately and resolved to his baseline within a week. A colonoscopy was performed in the meantime and biopsies demonstrated microscopic colitis (MC). He did not tolerate budesonide well so was stopped. However, a follow-up colonoscopy with biopsy in two months showed resolution of MC.

Recent advancements in the minimally invasive management of esophageal perforation, leaks, and fistulae.

INTRODUCTION: Historically, the gold standard management of esophageal perforations, leaks, and fistulae has been traditional open surgery, but it is associated with significant morbidity and mortality. Minimally invasive approaches offer alternatives to surgery in treating hemodynamically stable patients with such defects. In this review article, we will discuss the recent advancements in the minimally invasive management of esophageal perforations, leaks, and fistulas. AREAS COVERED: This review includes information from case reports, case series, and clinical trials on minimally invasive management of esophageal perforations, leaks, and fistulas. The focus is on the devices, outcomes, and application of the technology. EXPERT COMMENTARY: Minimally invasive treatment represents significant progress in the management of esophageal perforations, leaks, and fistulas. Based on current evidence, it seems safe and effective but it is evolving and more studies are needed to help draw definitive conclusions.

Devices for ex vivo heart and lung perfusion.

INTRODUCTION: The number of organs available for heart and lung transplantation is far short of the number that is needed to meet demand. Perfusion and ventilation of donor organs after procurement has led to exciting advances in the field of cardiothoracic transplantation. The clinical implications of this technology allows for techniques to evaluate the quality of an organ, active rehabilitation of organs after procurement and prior to implantation, and increased time between organ procurement and implantation. This ex-vivo perfusion technique has also been referred to in the lay press as the 'heart in a box' or 'lung in a box.' AREAS COVERED: This review includes information from case reports, case series, and clinical trials on ex vivo heart and lung perfusion. The focus is on the devices, ventilation and perfusion techniques, outcomes, and application of the technology. EXPERT COMMENTARY: Ex vivo perfusion of donor hearts and lungs prior to transplantation has proven to be a viable alternative to standard cold-preservation strategies. Its use has allowed for ongoing expansion of the donor pool. The biggest barriers to expansion of this technology are access, cost, and lack of evidence which clearly supports superior outcomes.

Inoperable patients with acute type A dissection: are they candidates for endovascular repair?

OBJECTIVES: The objectives are to (i) report characteristics and outcomes of patients with inoperable acute type A aortic dissection, (ii) describe proximal aortic morphology and (iii) identify potential for endovascular treatment of the entry tear. METHODS: Fifty-three (7.7%) of 686 patients with acute type A dissection between 2005 and 2015 were deemed inoperable. Chart review and active follow-up were performed for clinical characteristics and outcomes. Specific attention was directed at determining the reasons for inoperability. Twenty-four patients had computed tomography scans available for 3D reconstruction and imaging analysis. Measurements included diameter and cross-sectional area at multiple levels; plus lengths along the centreline, greater and lesser curves and outer wall of dissection. The entry tear location was identified. Entry tears between the sinotubular junction and innominate artery, or distal to the left subclavian artery, were considered amenable to endovascular repair. RESULTS: The reasons for inoperability were characterized as very high-risk 35 (66%) or prohibitive 18 (34%). Prohibitive risk factors included dementia, severe stroke, malperfusion and advanced malignancy. Thirty-day mortality occurred in 35 (66%). On imaging analysis, the sinotubular junction was <45 mm in 18 (75%). The false lumen was located along the greater curve in 16 (67%), lesser curve 2 (8%), anteriorly in 5 (21%) and posteriorly in 1 (4%). The entry tear was potentially amenable to coverage in 19 (79%) patients-between the sinotubular junction and innominate artery in 18 patients and distal to the left subclavian artery in 1 patient. The entry tear was in the aortic root and arch in 1 patient (4%) each and not visible in 3 patients (13%). CONCLUSIONS: Only one-third of inoperable patients are prohibitive risk for any intervention. The entry tears in most patients are potentially coverable with endovascular devices. Additional imaging and engineering analysis will guide the design of disease specific devices.

Optimization of gold nanoparticle-based real-time colorimetric assay of dipeptidyl peptidase IV activity.

Dipeptidyl peptidase IV (DPP-IV also referred to as CD-26) is a serine protease enzyme with remarkable diagnostic and prognostic value in a variety of health and disease conditions. Herein, we describe a simple and real-time colorimetric assay for DPP-IV/CD-26 activity based on the aggregation of gold nanoparticles (AuNPs) functionalized with the peptide substrates: Gly-Pro-Asp-Cys (GPDC) or Val-Pro-ethylene diamine-Asp-Cys (VP-ED-DC). Cleavage of the substrates by DPP-IV resulted in aggregation of the AuNPs with accompanying color change in the solution from red to blue that was monitored using either a UV-visible spectrophotometer or by the naked eye. Factors, such as time course of the reaction, stability of the functionalized AuNPs and the structure of the substrate that influence the cleavage reaction in solution were investigated. The effects of potential interference from serum proteins (lysozyme, thrombin and trypsin) on the analytical response were negligible. The detection limits when GPDC or VP-EN-DC functionalized AuNPs were used for DPP-IV assay were 1.2U/L and 1.5U/L, respectively. The VP-EN-DC method was preferred for the quantitative determination of DPP-IV activity in serum because of its wide linear range 0-30U/L compared to 0-12U/L for the GPDC assay. Recoveries from serum samples spiked with DPP-IV activity, between 5 and 25U/L, and using the VP-EN-DC modified AuNPs method ranged between 83.6% and 114.9%. The two colorimetric biosensors described here are superior to other conventional methods because of their simplicity, stability, selectivity and reliability.

Bone Mesenchymal Stem Cells with Growth Factors Successfully Treat Nonunions and Delayed Unions.

BACKGROUND: While the gold standard of treatment of nonunion is open autologous bone grafting, studies have shown that injecting bone marrow aspirate concentrates (BMAC) is effective in treating tibial nonunions with fracture gaps less than 5 mm. QUESTIONS/PURPOSES: We aim to demonstrate that combining BMAC with osteoinductive agents can effectively treat delayed or nonunion regardless of fracture gap size, nonunion site, or osteoinductive agent used. METHODS: In this non-randomized retrospective-prospective cohort study, 49 patients with tibial nonunion met the inclusion criteria and underwent BMAC injection with demineralized bone matrix (DBM) and/or recombinant human bone morphogenic protein-2 (rhBMP-2). Radiologic healing of the fracture was the primary outcome. Patients were followed until radiographic union was achieved or another procedure was performed. Radiographic healing was defined as bridging of three out of four cortices on anteroposterior and lateral films. RESULTS: There was no difference in the healing rate (p = 0.81) between patients with fracture gaps less than and greater than 5 mm. On multivariate analysis, the use of rhBMP-2 was associated with a lower healing rate compared to DBM (p = 0.036). Patients who underwent early intervention (within 6 months of fixation) had higher union rates (p = 0.04). CONCLUSION: This study shows that percutaneous BMAC injection combined with either DBM and/or rhBMP-2 is a safe and effective treatment for delayed or nonunion regardless of the fracture gap size or fracture site. DBM may be superior to rhBMP-2 in this procedure.

Second primary lung cancers: smokers versus nonsmokers after resection of stage I lung adenocarcinoma.

BACKGROUND: Smokers have a higher risk of developing non-small cell lung cancer (NSCLC) than never-smokers, but the relative risk of developing second primary lung cancer (SPLC) is unclear. Determining the risk of SPLC in smokers versus never-smokers after treatment of an initial cancer may help guide recommendations for long-term surveillance. METHODS: Patients who underwent resection for stage I adenocarcinoma were identified from a prospectively maintained institutional database. Patients with other histologies, synchronous lesions, or who received neoadjuvant or adjuvant therapy were excluded. The SPLCs were identified based on Martini criteria. RESULTS: From 1995 to 2012, a total of 2,151 patients underwent resection for stage I adenocarcinoma (308 never-smokers [14%] and 1,843 ever-smokers [86%]). SPLC developed in 30 never-smokers (9.9%) and 145 ever-smokers (7.8%). The SPLC was detected by surveillance computed tomography scan in the majority of patients (161; 92%). In total, 87% of never-smokers and 83% of ever-smokers had stage I SPLC. There was no significant difference in the cumulative incidence of SPLC between never-smokers and ever-smokers (p = 0.18) in a competing-risks analysis. The cumulative incidence at 10 years was 20.3% for never-smokers and 18.2% for ever-smokers. CONCLUSIONS: Although smokers have a greater risk of NSCLC, the risk of a second primary cancer developing after resection of stage I lung cancer is comparable between smokers and never-smokers. The majority of these second primary cancers are detectable at a curable stage. Ongoing postoperative surveillance should be recommended for all patients regardless of smoking status.

A natural vanishing act: the enzyme-catalyzed degradation of carbon nanomaterials.

Over the past three decades, revolutionary research in nanotechnology by the scientific, medical, and engineering communities has yielded a treasure trove of discoveries with diverse applications that promise to benefit humanity. With their unique electronic and mechanical properties, carbon nanomaterials (CNMs) represent a prime example of the promise of nanotechnology with applications in areas that include electronics, fuel cells, composites, and nanomedicine. Because of toxicological issues associated with CNMs, however, their full commercial potential may not be achieved. The ex vitro, in vitro, and in vivo data presented in this Account provide fundamental insights into the biopersistence of CNMs, such as carbon nanotubes and graphene, and their oxidation/biodegradation processes as catalyzed by peroxidase enzymes. We also communicate our current understanding of the mechanism for the enzymatic oxidation and biodegradation. Finally, we outline potential future directions that could enhance our mechanistic understanding of the CNM oxidation and biodegradation and could yield benefits in terms of human health and environmental safety. The conclusions presented in this Account may catalyze a rational rethinking of CNM incorporation in diverse applications. For example, armed with an understanding of how and why CNMs undergo enzyme-catalyzed oxidation and biodegradation, researchers can tailor the structure of CNMs to either promote or inhibit these processes. In nanomedical applications such as drug delivery, the incorporation of carboxylate functional groups could facilitate biodegradation of the nanomaterial after delivery of the cargo. On the other hand, in the construction of aircraft, a CNM composite should be stable to oxidizing conditions in the environment. Therefore, pristine, inert CNMs would be ideal for this application. Finally, the incorporation of CNMs with defect sites in consumer goods could provide a facile mechanism that promotes the degradation of these materials once these products reach landfills.

Brain evolution triggers increased diversification of electric fishes.

Communication can contribute to the evolution of biodiversity by promoting speciation and reinforcing reproductive isolation between existing species. The evolution of species-specific signals depends on the ability of individuals to detect signal variation, which in turn relies on the capability of the brain to process signal information. Here, we show that evolutionary change in a region of the brain devoted to the analysis of communication signals in mormyrid electric fishes improved detection of subtle signal variation and resulted in enhanced rates of signal evolution and species diversification. These results show that neural innovations can drive the diversification of signals and promote speciation.

Transferable graphene oxide films with tunable microstructures.

This report describes methods to produce large-area films of graphene oxide from aqueous suspensions using electrophoretic deposition. By selecting the appropriate suspension pH and deposition voltage, films of the negatively charged graphene oxide sheets can be produced with either a smooth "rug" microstructure on the anode or a porous "brick" microstructure on the cathode. Cathodic deposition occurs in the low pH suspension with the application of a relatively high voltage, which facilitates a gradual change in the colloids' charge from negative to positive as they adsorb protons released by the electrolysis of water. The shift in the colloids' charge also gives rise to the brick microstructure, as the concurrent decrease in electrostatic repulsion between graphene oxide sheets results in the formation of multilayered aggregates (the "bricks"). Measurements of water contact angle revealed the brick films (79°) to be more hydrophobic than the rug films (41°), a difference we attribute primarily to the distinct microstructures. Finally, we describe a sacrificial layer technique to make these graphene oxide films free-standing, which would enable them to be placed on arbitrary substrates.