Modeling the effect of subsurface interface defects on contact stiffness for ultrasonic atomic force microscopy

Cataloged from PDF version of article.We present a model predicting the effects of mechanical defects at layer interfaces on the contact stiffness measured by ultrasonicatomic force microscopy(AFM). Defects at subsurface interfaces result in changes at the local contact stiffness between the AFM tip and the sample. Surface impedance method is employed to model the imperfections and an iterative algorithm is used to calculate the AFM tip-surface contact stiffness. The sensitivity of AFM to voids or delaminations and disbonds is investigated for film-substrate combinations commonly used in microelectronic structures, and optimum defect depth for maximum sensitivity is defined. The effect of contact force and the tip properties on the defect sensitivity are considered. The results indicate that the ultrasonicAFM should be suitable for subsurface detection and its defect sensitivity can be enhanced by adjusting the applied force as well as by judicious choice of the AFM tip material and geometry. © 2004 American Institute of Physic

Heterotrophic ammonium removal by a novel hatchery isolate Acinetobacter calcoaceticus STB1

Cataloged from PDF version of article.A novel bacterial strain, STB1, was isolated from a commercial sea bass hatchery and found to display high heterotrophic ammonium removal characteristics at different concentrations of ammonium (NH4+-N). The species identity of STB1 was determined via 16S rRNA gene sequence analysis to be Acinetobacter calcoaceticus. We evaluated ammonium removal characteristics of STB1 at varying ammonium concentrations, and observed that STB1 can almost completely remove ammonium at low (50 mg l -1), and medium (100 mg l -1) concentrations within 72 h, while 45% ammonium removal was observed at a higher concentration (210 mg l -1) during the same period. Trace amount of the metabolized ammonium was converted to nitrite or nitrate and 22.16% of total nitrogen was incorporated into cell biomass, while 4.34% of total nitrogen was initially incorporated into cell biomass and subsequently released to the supernatant fraction in the 100 mg l -1 sample. Most of the remaining conversion products are expected to be gaseous denitrification products. Toxicological studies with Artemia salina (brine shrimp) nauplii revealed that STB1 strain is non-toxic to Artemia larvae, which suggests that STB1 can be safely and efficiently utilized in water quality enrichment in aquatic ecosystems. © 2012 Elsevier Ltd

Efficient ammonium removal from aquatic environments by Acinetobacter calcoaceticus STB1 immobilized on an electrospun cellulose acetate nanofibrous web

Cataloged from PDF version of article.A novel biocomposite material was developed by immobilizing an ammonia-oxidizing bacterial strain, Acinetobacter calcoaceticus STB1, on an electrospun porous cellulose acetate (CA) nanofibrous web. Ammonium removal characteristics of the STB1 immobilized CA nanofibrous web were determined at varying initial ammonium concentrations, and removal rates of 100%, 98.5% and 72% were observed within 48 h for 50 mg L-1, 100 mg L-1 and 200 mg L-1 samples, respectively. Most of the ammonia is inferred to be converted into nitrogen or is accumulated as bacterial biomass, as only trace amounts of ammonium were converted into nitrite or nitrate. Reusability test results indicate that, at an initial ammonium concentration of 100 mg L-1, bacteria-immobilized CA nanofibrous webs can be reused for at least 5 cycles. SEM images of the STB1/CA nanofibrous web after five cycles of reuse and rigorous washing demonstrate that bacterial biofilms strongly adhere to nanofiber surfaces

Fourier transform infrared spectroscopy as a novel approach for analyzing the biochemical effects of anionic surfactants on a surfactant-degrading acrobacter butzleri strain

Cataloged from PDF version of article.Anionic surfactant-biodegrading capability of an Arcobacter butzleri strain was analyzed under aerobic conditions. The A. butzleri isolate displayed efficient surfactant-biodegrading capacity for sodium dodecyl sulfate (SDS) at concentrations of up to 100 mg/L in 6 days, corresponding to 99.0% removal efficiency. Fourier transform infrared spectroscopy was applied to observe the effects of varying concentrations of SDS on the biochemistry of bacterial cells. Results suggest that protein secondary structures were altered in bacterial cells at sufficiently high SDS concentrations, concurrent with SDS biodegradation

Accelerated Born-Infeld Metrics in Kerr-Schild Geometry

We consider Einstein Born-Infeld theory with a null fluid in Kerr-Schild Geometry. We find accelerated charge solutions of this theory. Our solutions reduce to the Plebanski solution when the acceleration vanishes and to the Bonnor-Vaidya solution as the Born-Infeld parameter b goes to infinity. We also give the explicit form of the energy flux formula due to the acceleration of the charged sources.Comment: Latex file (12 pp

Dynamics and stability of the Godel universe

We use covariant techniques to describe the properties of the Godel universe and then consider its linear response to a variety of perturbations. Against matter aggregations, we find that the stability of the Godel model depends primarily upon the presence of gradients in the centrifugal energy, and secondarily on the equation of state of the fluid. The latter dictates the behaviour of the model when dealing with homogeneous perturbations. The vorticity of the perturbed Godel model is found to evolve as in almost-FRW spacetimes, with some additional directional effects due to shape distortions. We also consider gravitational-wave perturbations by investigating the evolution of the magnetic Weyl component. This tensor obeys a simple plane-wave equation, which argues for the neutral stability of the Godel model against linear gravity-wave distortions. The implications of the background rotation for scalar-field Godel cosmologies are also discussed.Comment: Revised version, to match paper published in Class. Quantum Gra

Can the ADO Index Be Used as a Predictor of Mortality from COVID-19 in Patients with COPD?

Esra Ertan Yazar,1 Gulsah Gunluoglu,2 Burcu Arpinar Yigitbas,1 Mukadder Calikoglu,3 Gazi Gulbas,4 Nilgün Y&inodot;lmaz Demirci,5 Nurhan Sarioglu,6 Fulsen Bozkus,7 Nevin Taci Hoca,5 Nalan Ogan,8 Seda Tural Onur,2 Muzaffer Onur Turan,9 Filiz Kosar,2 Evrim Eylem Akpinar,8 Burak Mete,10 Can Ozturk5 1Department of Chest Diseases, Istanbul Medeniyet University, Medical Faculty, Istanbul, Turkey; 2Department of Chest Diseases, Yedikule Chest Disease and Chest Surgery Research and Training Hospital, Istanbul, Turkey; 3Department of Chest Diseases, Mersin University, Medical Faculty, Mersin, Turkey; 4Department of Chest Diseases, Inonu University, Medical Faculty, Malatya, Turkey; 5Department of Chest Diseases, Gazi University, Medical Faculty, Ankara, Turkey; 6Department of Chest Diseases, Balikesir University, Medical Faculty, Balikesir, Turkey; 7Department of Chest Diseases, Kahramanmaras Sutcu Imam University, Medical Faculty, Kahramanmaras, Turkey; 8Department of Chest Diseases, Ufuk University, Medical Faculty, Ankara, Turkey; 9Department of Chest Diseases, Prof Dr, Izmir Katip Celebi University, Atatürk Research and Training Hospital, Izmir, Turkey; 10Department of Public Health Çukurova University, Medical Faculty, Adana, TurkeyCorrespondence: Esra Ertan Yazar, Istanbul Medeniyet University, Medical Faculty, Department of Chest Diseases, Istanbul, Turkey, Email [email protected]: Several studies have shown that the risk of mortality due to COVID-19 is high in patients with COPD. However, evidence on factors predicting mortality is limited.Research Question: Are there any useful markers to predict mortality in COVID-19 patients with COPD?.Study Design and Methods: A total of 689 patients were included in this study from the COPET study, a national multicenter observational study investigating COPD phenotypes consisting of patients who were followed up with a spirometry-confirmed COPD diagnosis. Patients were also retrospectively examined in terms of COVID-19 and their outcomes.Results: Among the study patients, 105 were diagnosed with PCR-positive COVID-19, and 19 of them died. Body mass index (p= 0.01) and ADO (age, dyspnoea, airflow obstruction) index (p= 0.01) were higher, whereas predicted FEV1 (p< 0.001) and eosinophil count (p= 0.003) were lower in patients who died of COVID-19. Each 0.755 unit increase in the ADO index increased the risk of death by 2.12 times, and each 0.007 unit increase in the eosinophil count decreased the risk of death by 1.007 times. The optimum cut-off ADO score of 3.5 was diagnostic with 94% sensitivity and 40% specificity in predicting mortality.Interpretation: Our study suggested that the ADO index recorded in the stable period in patients with COPD makes a modest contribution to the prediction of mortality due to COVID-19. Further studies are needed to validate the use of the ADO index in estimating mortality in both COVID-19 and other viral respiratory infections in patients with COPD.Keywords: body mass index, COVID-19, eosinophils, FEV1, mortality, pneumonia, pulmonary disease, chronic obstructiv

Оцінка оновлення основних засобів за рахунок позикових коштів

Оновлення основних засобів є актуальною проблемою сьогодення. Для багатьох підприємств кредити банків є чи не єдиним джерелом коштів на модернізацію виробничих потужностей. В даній статті нами були розглянуті можливості і перспективи приватних фірм для використання з цією метою позикових засобів, оцінений ступінь прозорості банківських установ, річні ставки за інвестиційними кредитами та інші умови їхнього надання.Modernizing of the basic assets is a topical problem of the present. For many business firms bank loans are may be the only source of funds for renewal of production facilities. In the article we have considered the opportunities and prospects for use of borrowed funds by private firms for this purpose, rated the degree of transparency of banking institutions, the annual rates of investment credits and other conditions of their granting

Overview of diagnosis and management of paediatric headache. Part I: diagnosis

Headache is the most common somatic complaint in children and adolescents. The evaluation should include detailed history of children and adolescents completed by detailed general and neurological examinations. Moreover, the possible role of psychological factors, life events and excessively stressful lifestyle in influencing recurrent headache need to be checked. The choice of laboratory tests rests on the differential diagnosis suggested by the history, the character and temporal pattern of the headache, and the physical and neurological examinations. Subjects who have any signs or symptoms of focal/progressive neurological disturbances should be investigated by neuroimaging techniques. The electroencephalogram and other neurophysiological examinations are of limited value in the routine evaluation of headaches. In a primary headache disorder, headache itself is the illness and headache is not attributed to any other disorder (e.g. migraine, tension-type headache, cluster headache and other trigeminal autonomic cephalgias). In secondary headache disorders, headache is the symptom of identifiable structural, metabolic or other abnormality. Red flags include the first or worst headache ever in the life, recent headache onset, increasing severity or frequency, occipital location, awakening from sleep because of headache, headache occurring exclusively in the morning associated with severe vomiting and headache associated with straining. Thus, the differential diagnosis between primary and secondary headaches rests mainly on clinical criteria. A thorough evaluation of headache in children and adolescents is necessary to make the correct diagnosis and initiate treatment, bearing in mind that children with headache are more likely to experience psychosocial adversity and to grow up with an excess of both headache and other physical and psychiatric symptoms and this creates an important healthcare problem for their future life

Methanogens, sulphate and heavy metals: a complex system

Anaerobic digestion (AD) is a well-established technology used for the treatment of wastes and wastewaters with high organic content. During AD organic matter is converted stepwise to methane-containing biogasa renewable energy carrier. Methane production occurs in the last AD step and relies on methanogens, which are rather sensitive to some contaminants commonly found in wastewaters (e.g. heavy metals), or easily outcompeted by other groups of microorganisms (e.g. sulphate reducing bacteria, SRB). This review gives an overview of previous research and pilot-scale studies that shed some light on the effects of sulphate and heavy metals on methanogenesis. Despite the numerous studies on this subject, comparison is not always possible due to differences in the experimental conditions used and parameters explained. An overview of the possible benefits of methanogens and SRB co-habitation is also covered. Small amounts of sulphide produced by SRB can precipitate with metals, neutralising the negative effects of sulphide accumulation and free heavy metals on methanogenesis. Knowledge on how to untangle and balance sulphate reduction and methanogenesis is crucial to take advantage of the potential for the utilisation of biogenic sulphide as a metal detoxification agent with minimal loss in methane production in anaerobic digesters.The research was financially supported by the People Program (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007-2013 under REA agreement 289193