Monitoring the Electrochemical Failure of Indium Tin Oxide Electrodes via Operando Ellipsometry Complemented by Electron Microscopy and Spectroscopy.

Transparent conductive oxides such as indium tin oxide (ITO) are standards for thin film electrodes, providing a synergy of high optical transparency and electrical conductivity. In an electrolytic environment, the determination of an inert electrochemical potential window is crucial to maintain a stable material performance during device operation. We introduce operando ellipsometry, combining cyclic voltammetry (CV) with spectroscopic ellipsometry, as a versatile tool to monitor the evolution of both complete optical (i.e., complex refractive index) and electrical properties under wet electrochemical operational conditions. In particular, we trace the degradation of ITO electrodes caused by electrochemical reduction in a pH-neutral, water-based electrolyte environment during electrochemical cycling. With the onset of hydrogen evolution at negative bias voltages, indium and tin are irreversibly reduced to the metallic state, causing an advancing darkening, i.e., a gradual loss of transparency, with every CV cycle, while the conductivity is mostly conserved over multiple CV cycles. Post-operando analysis reveals the reductive (loss of oxygen) formation of metallic nanodroplets on the surface. The reductive disruption of the ITO electrode happens at the solid-liquid interface and proceeds gradually from the surface to the bottom of the layer, which is evidenced by cross-sectional transmission electron microscopy imaging and complemented by energy-dispersive X-ray spectroscopy mapping. As long as a continuous part of the ITO layer remains at the bottom, the conductivity is largely retained, allowing repeated CV cycling. We consider operando ellipsometry a sensitive and nondestructive tool to monitor early stage material and property changes, either by tracing failure points, controlling intentional processes, or for sensing purposes, making it suitable for various research fields involving solid-liquid interfaces and electrochemical activity.

Association of Hypertensive Intracerebral Hemorrhage with Left Ventricular Hypertrophy on Transthoracic Echocardiography.

INTRODUCTION: Arterial hypertension is the most frequent cause for spontaneous intracerebral hemorrhage (sICH) and may also cause left ventricular hypertrophy (LVH). We sought to analyze whether hypertensive sICH etiology is associated with LVH. METHODS: We analyzed consecutive patients with sICH who were admitted to our tertiary stroke center during a four-year period and underwent transthoracic echocardiography (TTE) as part of the diagnostic work-up. We defined hypertensive sICH as typical localization of hemorrhage in patients with arterial hypertension and no other identified sICH etiology. We defined an increased end-diastolic interventricular septal wall thickness of ≥11 mm on TTE as a surrogate parameter for LVH. RESULTS: Among 395 patients with sICH, 260 patients (65.8%) received TTE as part of their diagnostic work-up. The median age was 71 years (interquartile range (IQR) 17), 160 patients (61.5%) were male, the median baseline National Institute of Health Stroke Scale (NIHSS) score was 8 (IQR 13). Of these, 159 (61.2%) patients had a hypertensive sICH and 156 patients (60%) had LVH. In univariable (113/159 (71.1%) vs. 43/101 (42.6%); odds ratio (OR) 3.31; 95% confidence interval (CI95%) 1.97-5.62); and multivariable (adjusted OR 2.95; CI95% 1.29-6.74) analysis, hypertensive sICH was associated with LVH. CONCLUSIONS: In patients with sICH, LVH is associated with hypertensive bleeding etiology. Performing TTE is meaningful for diagnosis of comorbidities and clarification of bleeding etiology in these patients. Future studies should include long-term outcome parameters and assess left ventricular mass as main indicator for LVH.

Analysis of three-dimensional biofilms on different material surfaces.

Biofilms cause complications and high costs in both industry and medicine. Of particular interest are bacterial infections of prosthetic materials, which usually cannot be eliminated due to the high antibiotic resistance known for bacteria forming biofilms. The search for new materials and coatings with lower colonization potential and antibacterial activity is of great importance to reduce biofilm formation. However, there is no standardized procedure to examine the colonization characteristics of bacteria in the biofilm state in situ. Here, we describe an automated epifluorescence microscopy system for the semi-quantitative analysis of three-dimensional (3D) biofilms on various surfaces. To analyze adherent bacteria, three materials (glass, steel and titanium) were incubated with bacteria in a flow chamber system. After fluorescence staining of the bacteria, automated image capturing, quantification of the bacteria, measurement of the colonized area and determination of the 3D biofilm height were carried out by using novel software. Furthermore, the materials were examined for their surface topography using white light scanning interferometry. Titanium compared to glass showed a significantly higher number of adherent bacteria. We argue that this was due to the higher microroughness of titanium. The colonized area was in accordance with the number of adherent bacteria and was also significantly larger on titanium coupons compared to glass. Maximum 3D biofilm height on glass coupons was significantly lower compared to the ones on steel and titanium. This novel method enables the standardized, automated investigation of the colonization with bacteria on different materials. This approach can considerably support the characterization of new material surfaces and their innovative coatings by analyzing the amount of attached bacteria and thickness of biofilms in situ and eliminates the need of conventional cultivation.

A Systematic Review of the Semi-Sitting Position in Neurosurgical Patients with Patent Foramen Ovale: How Frequent Is Paradoxical Embolism?

BACKGROUND: The semi-sitting position is preferred in some surgeries of the posterior fossa and the cervical spine. At the same time, it is associated with a risk of air embolism. In the presence of a patent foramen ovale (PFO) with an intracardial right-to-left shunt, an air embolism can result in a paradoxical embolism to the heart or brain. It is unclear whether the risk-benefit ratio favors the semi-sitting position in this scenario. METHODS: We conducted a systematic review of the relevant studies published after 2007 by searching the PubMed, Science Direct, and Cochrane Database of Systematic Reviews databases. Studies in which the presence of PFO was stated and the occurrence of paradoxical embolism was evaluated in patients who underwent neurosurgical procedures in the semi-sitting position were included in our analysis. RESULTS: We identified 4 observational studies with a total of 977 patients who underwent surgery of the posterior fossa or cervical spine in the semi-sitting position; among these, 82 had a PFO. Air embolism occurred in 33 of these 82 patients (40.2%). No paradoxical embolisms were detected. CONCLUSIONS: In experienced medical centers, neurosurgery in the semi-sitting position is feasible with acceptable risk even in patients with PFO. If the PFO is large, or if a permanent right-to-left shunt is present in a patient with a history of paradoxical embolism, it may be reasonable to repair the PFO before surgery if the semi-sitting position is strongly preferred. The risk analysis must be done on a case-by-case basis.

XPS depth profiling of an ultrathin bioorganic film with an argon gas cluster ion beam.

The growing interest in artificial bioorganic interfaces as a platform for applications in emerging areas as personalized medicine, clinical diagnostics, biosensing, biofilms, prevention of biofouling, and other fields of bioengineering is the origin of a need for in detail multitechnique characterizations of such layers and interfaces. The in-depth analysis of biointerfaces is of special interest as the properties of functional bioorganic coatings can be dramatically affected by in-depth variations of composition. In worst cases, the functionality of a device produced using such coatings can be substantially reduced or even fully lost.

Diagnostic Impact of Transesophageal Echocardiography in Patients with Acute Cerebral Ischemia.

OBJECTIVES: Transesophageal echocardiography (TEE) is the diagnostic gold standard for the detection of structural heart diseases as potential sources of cardiac emboli in patients with acute cerebral ischemia. We sought to determine the diagnostic yield of TEE in patients with acute ischemic stroke or transient ischemic attack (TIA). METHODS: We retrospectively analyzed consecutive patients with acute cerebral ischemia who were admitted to our hospital between October 2008 and December 2011. TEE reports were screened for detection of cardiac source of embolism judged by the recommendation to change medical management. We performed univariate and multivariate analyses to identify predictors of clinically relevant TEE findings among baseline characteristics. RESULTS: Of 3314 patients with ischemic stroke or TIA, TEE was performed in 791 (24%) patients (mean age 64 ± 13 years, 589 [74%] ischemic stroke, 202 [26%] TIA). A potential cardioembolic source was found in 71 (9%) patients with patent foramen ovale with atrial septal aneurysm being the most common finding (24/71 patients, 34%). In multivariate analysis, peripheral vascular disease (OR 2.57; 95%CI 1.00-6.61), imaging evidence of infarction in multiple locations (OR 4.13; 95%CI 1.36-12.58), and infarction in the posterior circulation (OR 2.11; 95%CI 1.01-4.42) were associated with the identification of a potential cardioembolic source with TEE. CONCLUSION: TEE identified a potential structural cardioembolic source in nearly 10% of our selected patient population with acute ischemic stroke or TIA, thus underlining its diagnostic value. Our data suggest that patients with hitherto unknown stroke etiology should be considered for additional TEE.

Haemoptysis due to pulmonary venous stenosis.

Haemoptysis is a potentially life-threatening condition with the need for prompt diagnosis. In about 10-20% of all cases the bleeding source remains unexplained with the standard diagnostic approach. The aim of this article is to show the necessity of widening the diagnostic approach to haemoptysis with consideration of pulmonary venous stenosis as a possible cause of even severe haemoptysis and haemoptoe. A review of the literature was performed using the Medline/PubMed database with the terms: "pulmonary venous stenosis", "pulmonary venous infarction" and "haemoptysis". Further references from the case reports were considered. 58 case reports and case collections about patients with haemoptysis due to pulmonary venous stenosis were detected. This review gives an overview about the case reports and discusses the underlying pathophysiology and the pros and cons of different imaging techniques for the detection of pulmonary venous stenosis. Several conditions predispose to the obstruction of the mediastinal pulmonary veins. Clinical findings are unspecific and may be misleading. Pulmonary venous stenosis can be detected using several imaging techniques, yet three-dimensional magnetic resonance-angiography and three-dimensional contrast-enhanced computed tomography are the most appropriate. Pulmonary venous stenosis should be considered in patients with haemoptysis.

Isolated rupture of the right upper pulmonary vein: a blunt cardiac trauma case.

A 37-year-old woman who sustained blunt chest trauma as a result of a car accident was found unconscious at the accident site with signs of circulatory compromise. Computed tomographic trauma screening excluded thoracic, intracranial, and intra-abdominal bleeding, or other pathologic findings, except a small circumferential hemopericardium. Echocardiography revealed a hemopericardium that was partially clotted and the beginning of compression of the right ventricle. Because of progressive hemodynamic compromise, the decision was made for operative exploration. After a median sternotomy, the resultant excessive bleeding necessitated extracorporeal circulation. Careful inspection revealed isolated rupture of the upper right pulmonary vein, which was successfully repaired.

Intimal pulmonary artery sarcoma presenting as severe dyspnea and right heart insufficiency.

BACKGROUND: Pulmonary artery sarcoma is a rare tumor with a poor prognosis. CASE REPORT: We report the case of a 64-year-old man with an intimal pulmonary artery sarcoma presenting with severe high oxygen flow-demanding dyspnea and weight loss of 12 kg in the last 6 months. On echocardiography, right heart insufficiency, markedly elevated right ventricular pressure, a pressure gradient along the right outflow tract, and a tumor mass adherent to the wall of the truncus pulmonalis were detected. The tentative diagnosis by echocardiographic findings was pulmonary artery sarcoma. Computed tomography of the thorax and 18-fluorodeoxyglucose positron emission tomography showed an advanced local tumor manifestation. Surgical resection of the tumor to improve hemodynamics confirmed the diagnosis. CONCLUSIONS: Pulmonary artery sarcoma should be considered as a rare differential diagnosis in patients with dyspnea due to right heart failure, particular in the case of additional weight loss, and echocardiographic examination is a useful first diagnostic approach in establishing the diagnosis.

An intrathoracic arteriovenous malformation discovered as an extremely uncommon reason of neonatal congestive cardiac failure.

Congenital arteriovenous malformations are rare causes of congestive cardiac failure in neonates. The most common sites are in the head and liver, but other sites include the thorax, the abdomen and the limbs. The onset of failure is usually not in the immediate neonatal period, but later on in life, albeit that lesions such as the arteriovenous malformation of the vein of Galen, and other arteriovenous malformations in different locations which produce high flow can present early. We describe here the first case, to the best of our knowledge, of prenatal detection of an intrathoracic arteriovenous malformation producing neonatal cardiac failure, which was successfully treated by surgery postnatally.

Adrenocortical hormones in survivors and nonsurvivors of severe sepsis: diverse time course of dehydroepiandrosterone, dehydroepiandrosterone-sulfate, and cortisol.

OBJECTIVE: Activation and suppression of immune responses are crucial events during sepsis. Based on substantial new data, a complex picture of differential immune-enhancing and immunosuppressive actions of adrenocortical steroids is emerging. The adrenal androgen dehydroepiandrosterone and its precursor, dehydroepiandrosterone-sulfate, show a considerable decrease with increasing age and serve as functional antagonists to endogenous glucocorticoids. Therefore, we examined time-dependent changes in dehydroepiandrosterone, dehydroepiandrosterone-sulfate, cortisol, adrenocorticotropin, and inflammatory variables in surviving and nonsurviving patients with severe sepsis. DESIGN: Prospective observational study in consecutive patients. SETTING: Medical and interdisciplinary intensive care units in two university hospitals and one city hospital. PATIENTS: Thirty nonsurgical patients (25 men and 5 women) with severe sepsis (American College of Chest Physicians/Society of Critical Care Medicine criteria); 15 survivors (mean age, 54 +/- 14 yrs; Acute Physiology and Chronic Health Evaluation III score, 59 +/- 35) and 15 nonsurvivors (mean age, 63 +/- 15 yrs; Acute Physiology and Chronic Health Evaluation III score, 67 +/- 24) were included. Hormones were compared individually and between survivors/nonsurvivors by sequential blood drawings from early sepsis till time of recovery/death. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During early sepsis, cortisol (nmol/L) was not significantly higher in survivors than nonsurvivors (750 +/- 121 vs. 454 +/- 92, p <.08) and decreased in survivors (p <.01) during late sepsis. During early sepsis, dehydroepiandrosterone-sulfate (percentage of age-matched normal levels) was higher in survivors than nonsurvivors (85 +/- 19 vs. 22 +/- 7, p <.01). Dehydroepiandrosterone-sulfate decreased in survivors (p =.0001) but remained low in nonsurvivors during late sepsis. Dehydroepiandrosterone (percentage of age-matched normal levels) was not significantly elevated in survivors compared to nonsurvivors during early sepsis (282 +/- 42 vs. 214 +/- 63, p <.08). Dehydroepiandrosterone decreased in survivors (p <.01) but not in nonsurvivors during late sepsis. Linear regression for dehydroepiandrosterone levels showed a reconstitution of age dependence only in survivors during recovery. Adrenocorticotropin levels did not change. The dehydroepiandrosterone-sulfate/cortisol ratio decreased significantly in both survivors and nonsurvivors, whereas dehydroepiandrosterone/cortisol ratio only decreased in survivors during course of sepsis. CONCLUSIONS: During sepsis, adrenal androgens and glucocorticoids show a diverse time-dependent course in survivors and nonsurvivors.

Outcome and prognostic features of intensive care unit treatment in patients with hematological malignancies.

OBJECTIVE: To assess the outcome of intensive care unit (ICU) treatment in patients with hematological malignancies. DESIGN AND SETTING: Retrospective cohort study in the medical ICU of a university hospital. PATIENTS: 104 critically ill patients after receiving conventional chemotherapy or autologous hematopoietic stem cell transplantation. INTERVENTIONS: We analyzed demographic data, underlying disease, intensity of antineoplastic regimen, cause of admission, need for mechanical ventilation, and hemofiltration, ICU survival, and survival after discharge, furthermore neutrophil count, C-reactive protein (150 mg/l), antithrombin III, prothrombin time, and SAPS II (50) at ICU admission. All recorded variables were evaluated for prognostic relevance by univariate and multivariate analyses. MEASUREMENTS AND RESULTS: Overall ICU mortality was 44%, with significantly higher mortality in ventilated patients (74% vs. 12% in nonventilated patients, p<0.001). Overall survival for the entire group 6 months and 1 year after ICU admission was 33% and 29%, respectively. Multivariate analysis revealed mechanical ventilation and SAPS II as independent prognostic factors of both ICU mortality and long-term survival, while C-reactive protein predicted only ICU mortality. CONCLUSIONS: The outcome of patients not requiring ventilatory support in this study was encouraging, while invasive ventilation was again confirmed as predicting a dismal prognosis in this population. Efforts should be directed to avoiding this procedure by reducing the pulmonary toxicity of antineoplastic treatment and to making ventilatory support more tolerable.