An electromechanical system for characterization of piezoelectric materials

Piezoelectric materials have been used in medical applications for a long time due to their unique characteristics, which is to respond to mechanical stimulation by producing an electrical current and vice versa. They perform a pivotal role in medical applications both for diagnostic and therapeutic purposes. In this regard, characterizing the piezoelectric properties of these materials is crucial for their usage. In this particular study, an electromechanical system for measurement of piezoelectric output signals is designed and tested. The project is motivated by the question: can the piezoelectric properties be characterized by applying different mechanical stimulation waveforms and frequencies. Two well-known piezoelectric materials, Polyvinylidene Fluoride (PVDF) and Lead Zirconate Titanate (PZT), are used as samples in this project to demonstrate the device operation. In addition, a non-piezoelectric material is included as a control group

Modulation of cerebellar purkinje cell activity with low intensity electric and ultrasound stimulation

Non-invasive brain stimulation (NIBS) techniques garner significant interest due to their potential to offer instantaneous and region-specific treatments to neurological disorders. The cerebellum is one of the target sites for NIBS methods due to its central role in motor and cognitive functions. Among several modulation techniques, transcranial electric stimulations (tEs), in particular, transcranial direct and alternating current stimulations (tDCs/tACs), and low intensity focused ultrasound stimulation (LIFUS) show encouraging outcomes in clinical applications. tDCs and tACs are favored due to their low cost and accessibility while LIFUS offers high spatial resolution and deeper penetration without affecting the surrounding structures. In order to better understand the underlying mechanism of these methods in the cerebellum, animal studies are needed since these experiments require invasive surgeries. The goal of this study is to investigate the response of cerebellar PCs to electric and ultrasound stimulation in an animal model. The first objective is to measure the electric field (e-field) distribution inside the brain parenchyma since e-field is the main parameter that determines the local effects of electrical stimulation. The results of this part show that e-field decays exponentially through horizontal and vertical directions from the stimulating electrode and scattered by the skin up to 80%. Then, tACS and tDCS are applied to the cerebellar cortex respectively while recording the extracellular spike activity from the cerebellar PCs. The activity of PCs is important because they generate the sole output from the cerebellar cortex, which in turn modifies the output of the deep cerebellar nuclei (DCN). The results of this part demonstrate that the direction of e-field is highly correlated with the level of modulation measured on the PCs. Applying the e-field parallel to the dendritic tree of the PCs generates the highest modulation level. Our data show that PCs have a characteristic response to both DC and AC fields, including entrainment of the simple spike activity at high frequencies. Our findings for the LIFUS also show that spike timing of PCs is strongly entrained with the pulsed ultrasound stimulation, and the level of the entrainment is inversely correlated with the pulse width. In summary, the low intensity electric and ultrasound stimulation are able to effectively modulate the PC activity in the cerebellar cortex. This warrants research to further look into the mechanism of tES and LIFUS acting on the cerebellar cortex at the cellular level

Sonbahar Mevsiminde İki Örnekleme Metodu Kullanarak Edirne İlinin Doğusunda Havayla Taşınan Fungal Konsantrasyonların Belirlenmesi

DergiPark: 245861trakyafbdGece ve gündüz saatlerinde fungal konsantrasyonlar değişiklik gösterebilir. Kuru sporlar havaya gündüz salınırken nem oranı daha yüksek olan sporlar gece salınmaktadırlar. Türkiye’de havayla taşınan funguslar ile ilgili çalışmalar çok azdır ve yalnızca bazı şehirlerde günlük ve haftalık incelemeler yapılmıştır. Bu çalışmada Edirne şehri günlük fungal konsantrasyonlarının belirlenmesi amaçlanmıştır. Örnekler yerden 11 m yükseklikten alınmıştır. Örneklemeler 11 Ekim 2002 – 15 Kasım 2002 tarihleri arasında, hergün aynı saatlerde olmak üzere birer haftalık zaman dilimlerinde sabah 08.00 ve akşam 20.00’de yapılmıştır. Fungus izolasyonu için yerçekimine dayalı petri plak metodu ve volumetrik örnekleme metodu kullanılmıştır. Sıcaklık ve nısbi nem iklimsel faktörlerin fungal sporları etkileyip etkilemedikleri istatistiki olarak incelenmiş ve fungus sayıları, nısbi nem ve sıcaklık arasında korelasyon bulunmuştur. 42 petri plağına izole edilen toplam 800 fungus kolonisi bulunma sıklıkları belirlenerek cins düzeyinde tanımlamaları yapılmıştır. Volumetrik metot ile m3 de 9337 cfu mikrofungus belirlenmiştir. En baskınları Alternaria, Penicillium ve Trichoderma olan 7 fungus cinsi teşhis edilebilmiştir.Fungal spore concentrations vary during day and night. Dry spore types are released during the day, whereas wet spores that have more humidity ratio are released into the air at night. Studies on airborne fungi in Turkey are very rare, and they are daily and weekly monitored only in some cities. The aim of our study was to determine the daily fungal concentrations in Edirne, Turkey. All samples were taken from a level of 11 m. above ground. The sampling time was carried out bihourly in the day, from 8 am to 20 pm, once a week from October 11 to November 15, 2002. Two sampling methods were used for the isolation of fungi: A gravitational and a volumetric method. Statistical analysis was performed in order to determine the relationship between some environmental factors and airborne counts and some correlation were found between the fungal numbers, relative humidity, sampling hours and temperature. A total of 800 fungal colonies in 42 petri dishes were isolated, quantified to determine the frequency of occurrence and then identified as genus level. 9337 cfu/m3 microfungi were determined by volumetric sampling. Seven fungal genera could be determined, among them Cladosporium and Alternaria were found as the most predominant fungi, followed by Penicillium and Trichoderma

Edirne Şehrinin Doğusunda İki Örnekleme Metodu Kullanılarak Havayla Taşınan Fungusların Sabah Ve Akşam Konsantrasyonlarının Belirlenmesi

DergiPark: 245939trakyafbdEylül- Kasım 2002 tarihleri arasında sabah ve akşam saatlerinde havayla taşınan fungusların konsantrasyonlarının değişimlerini belirlemek amacı ile ayda üç kez olmak üzere fungal örnekleme yapılmıştır. Bu amaç için iki metot uygulanmıştır. Örnekler, Yerçekimine Dayalı Petri Plak Metodu ile, Rose Bengal Streptomisin agar içeren petri plakları 15 dakika havayla temas ettirilerek ve Volumetrik bir örnekleyici kullanarak alınmıştır. Alternaria, Aspergillus, Cladosporium, Penicillium, Rhizopus, Scopuloriopsis, Trichoderma, Ulocladium cislerine ve Dematiaceae familyasına ait 9680 koloni gözlenmiştir. Bunlardan Cladosporium, Alternaria ve Penicillium cisleri Yerçekimine Dayalı Petri Plak Metodu için 120, 149 ve 4, Volumetrik örnekleme için de 3133, 2733 ve 1134 koloni sayıları ile baskın cinsleri oluşturmuşlardır. Değişkenlerin normal dağılıma uygun olup olmadıklarını belirlemek için Kolmogorow-Simirnov testi uygulanmıştır. Daha sonra yapılan Korelasyon analizi sonucunda Volumetrik metotla izole edilen cinslerin sabah ve akşamki koloni sayıları arasında anlamlı bir ilişki bulunmuştur (r= 0.489 ). Yerçekimine Dayalı Petri Plak Metoduna göre izole edilen cinslerin sabah ve akşamki koloni sayıları arasında da yine anlamlı bir ilişki bulunmuştur (r= 0.667). Her iki metoda göre izole edilen cinslerin sabah ve akşamki koloni sayıları istatistiki olarak analiz edilmiş ve aralarında bir ilişki olduğu saptanmıştır (r= 0.486 ve r= 0.761).In order to determine the variations of fungal concentrations duiring morning and evening, fungal samples were taken tree times a month between September- November 2002. Two sampling methods were employed. Samples were taken either by gravitation method for which Petri dishes containing Rose Bengal streptomycin agar were exposed to air for 15 min. or by using a volumetric sampler. A total of 9680 colonies belonging to Alternaria (Nees), Aspergillus (Fr.:Fr.), Cladosporium (Link), Penicillium (Link), Rhizopus (Ehrenberg), Scopuloriopsis (Bainier), Trichoderma Pers, Ulocladium Preus, and to unidentified genera from Dematiaceae were observed. Of these, Cladosporium, Alternaria and Penicillium were the dominating taxa with their colonial counts 3133, 2733 and 1134 for gravitational method and 120, 149 and 4 for volumetric sampling method, respectively. We used a Kolmogorov-Smirnov test for the fitness of the variables to normal distribution. For morning and evening counts of the sampler method, we found a significant relationship (r = 0.489, P lt; 0.001) as revealed by correlation of analysis. When colonial counts of morning and evening samples of the gravitational method were compared again a significant relationship was found (r = 0.667). Morning and evening counts of both methods were analysed statistically (r = 0.486 and r = 0.761 respectively)

Contents of phenolic and flavonoid compounds in Isatis demiriziana Mısırdalı: an endemic to the Southeast

Isatis demiriziana Mısırdalı plant contains a number of compounds which has anticarcinogenic, antioxidant and other preventive effects. In this study, the flavonoid and phenolic contents in the plant samples harvested in the vegetative (leaf and root) and full flowering season (flower, leaf and root) were determined by LC-MS/MS. Among the 27 compounds studied, malic acid was found to be the most abundant compound in the methanolic extracts of samples and the amount of malic acid of vegetative root extracts were the highest (30124,37 µg g-1 dry-extract). Moreover, it was also determined considerable amount of salicylic acids and p-coumaric in the root extracts. This study is the first detailed study on the phenolic and flavonoid compounds of I. demiriziana. Based on the findings of this study, in further researches might be refered as an additional source in production of phenolic and flavonoid compounds

Data Base Design with GIS in Ecosystem Based Multiple Use Forest Management in Artvin, Turkey: A Case Study in Balcı Forest Management Planning Unit

In Turkey, the understanding of planning focused on timber production has given its place on Multiple Use Management (MUM). Because the whole infrastructure of forestry with inventory system leading the way depends on timber production, some cases of bottle neck are expected during the transition period. Database design, probably the most important stage during the transition to MUM, together with the digital basic maps making up the basis of this infrastructure constitute the main point of this article. Firstly, the forest management philosophy of Turkey in the past was shortly touched upon in the article. Ecosystem Based Multiple Use Forest Management (EBMUFM) approaches was briefly introduced. The second stage of the process of EBMUFM, database design was described by examining the classical planning infrastructure and the coverage to be produced and consumed were suggested in the form of lists. At the application stage, two different geographical databases were established with GIS in Balcı Planning Unit of the years 1984 and 2006. Following that the related basic maps are produced. Timely diversity of the planning unit of 20 years is put forward comparatively with regard to the stand parameters such as tree types, age class, development stage, canopy closure, mixture, volume and increment

Determination of aflatoxin M1 on follow-on milk by ELISA method

Önemli bir besin kaynağı olan süt, bebek beslenmesinde kullanılmakta ve tüm dünyada tüketilmektedir. Devam sütlerine geçtiği bilinen kimyasal kontaminantlardan biri mikotoksinlerdir. Küfler tarafından üretilen ve devam sütlerine geçebilen mikotoksinler bebekte sağlık riski oluşturabilir. Mikotoksinlerin toksik etkilerinin önlenmesi için bebeğin normal büyüme ve gelişimi için en önemli besinlerden biri olan devam sütündeki aflatoksin M1 düzeylerinin belirlenmesi önemlidir. Süt kontaminantı olarak aflatoksinlerin kontrolü ile ilgili sosyal koruma projelerinin ve devam sütleri ile ilgili farkındalığın arttırılması halk sağlığı korunması açısından önem arz eder. Çalışmamızda, yeni doğanların diyetlerinde aldığı ürün olan devam sütlerinde, aflatoksin M1’in varlığı ve halk sağlığı bakımından önemi araştırılmıştır. Bu amaçla, 7 farklı firmadan, farklı seri numaralarına sahip süt örneklerini içeren 60 adet devam sütü toplanmıştır. Çalışmamızda Enzyme-linked immunosorbent assay (ELISA) yöntemi kullanılarak devam sütlerinde aflatoksin M1miktarları araştırılmıştır. Avrupa Birliğine uyum çerçevesinde hazırlanmış olan 2008/26 sayılı gıda maddelerindeki kontaminasyonların maksimum limitleri hakkındaki Türk Gıda Kodeksi (TGK) Tebliğinde; çiğ süt, UHT süt ve süt içeren ürünlerin yapımında kullanılan sütlerde maksimum AFM1 miktarının 0.05µg/kg (parts per billion) olması gerektiği belirtilmiştir. Aflatoksin M1 konsantrasyonları hesaplandığında; 0.05 ppb konsantrasyon aralığında Aflatoksin M1 içeren 23 örnek tespit edilmiştir. Sonuç olarak Türk Gıda Kodeksi limit değerini aşan 23 örnek halk sağlığı açısından önem arz etmektedir. Beslenmede devam sütünün sıklıkta tüketildiği ve önemli bir rol oynadığı bebek yaş grubunda, bu ürünler piyasaya çıkmadan önce Aflatoksin M1 varlığının saptandığı daha kapsamlı araştırmaların yapılmasının uygun olduğu düşünülmektedir.Milk, which is an important source of nutrition is used for infant feeding and consumed widely all over the world. Mycotoxins are one of the chemical contaminants that are known to pass through milk. They are produced by molds and pass through milk, and may cause health problems in infants. Determination of aflatoxin M1 levels in follow-on milks which is one of the most important nutrients for healthy grown babies is important in prevention of toxic effects of mycotoxins. Promoting social protection studies concerning aflatoxins as milk contaminants and raising awareness on follow-on milks is important in protection of public health. In our study, investigation of aflatoxin M1 in follow-on milks; a product that newborns take in their diet, and to evaluate the results in terms of public health. For this purpose, 60 follow-on milk samples with different serial numbers were collected from 7 companies. In Turkish Food Codex Communique related to the contaminations in food products with in accordance with the law no 2008/6 for preparation compliance as part of European Onion, indicated that the raw milk, UHT milk and other milks used for production of some products containing milk, maximum aflatoxin M1 should be 0.05 µg/kg (parts per billion). Aflatoxin M1 concentrations were determined by Enzyme-Linked Immunosorbent Assay (ELISA). Our results showed that 37 samples contained aflatoxin M1 with 0.05 parts per billion concentrations. In conclusion, the latter 23 samples including aflatoxin M1 values above Turkish Food Codex limits are important in terms of public health

Systemic and local antibiotic prophylaxis in the prevention of Staphylococcus epidermidis graft infection

BACKGROUND: The aim of the study was to investigate the in vivo efficacy of local and systemic antibiotic prophylaxis in the prevention of Staphylococcus (S.) epidermidis graft infection in a rat model and to evaluate the bacterial adherence to frequently used prosthetic graft materials. METHODS: Graft infections were established in the subcutaneous tissue of 120 male Wistar rats by implantation of Dacron/ePTFE grafts followed by topical inoculation with 2 × 10(7 )CFUs of clinical isolate of methicillin-resistant S. epidermidis. Each of the graft series included a control group, one contaminated group that did not receive any antibiotic prophylaxis, two contaminated groups that received systemic prophylaxis with teicoplanin or levofloxacin and two contaminated groups that received teicoplanin-soaked or levofloxacin-soaked grafts. The grafts were removed 7 days after implantation and evaluated by quantitative culture. RESULTS: There was significant bacterial growth inhibition in the groups given systemic or local prophylaxis (P < 0.05). Methicillin-resistant S. epidermidis had greater affinity to Dacron graft when compared with ePTFE graft in the untreated contaminated groups (P < 0.05). CONCLUSION: The study demonstrated that the usage of systemic or local prophylaxis and preference of ePTFE graft can be useful in reducing the risk of vascular graft infections caused by staphylococcal strains with high levels of resistance

The Amsterdam Declaration on Fungal Nomenclature

The Amsterdam Declaration on Fungal Nomenclature was agreed at an international symposium convened in Amsterdam on 19–20 April 2011 under the auspices of the International Commission on the Taxonomy of Fungi (ICTF). The purpose of the symposium was to address the issue of whether or how the current system of naming pleomorphic fungi should be maintained or changed now that molecular data are routinely available. The issue is urgent as mycologists currently follow different practices, and no consensus was achieved by a Special Committee appointed in 2005 by the International Botanical Congress to advise on the problem. The Declaration recognizes the need for an orderly transitition to a single-name nomenclatural system for all fungi, and to provide mechanisms to protect names that otherwise then become endangered. That is, meaning that priority should be given to the first described name, except where that is a younger name in general use when the first author to select a name of a pleomorphic monophyletic genus is to be followed, and suggests controversial cases are referred to a body, such as the ICTF, which will report to the Committee for Fungi. If appropriate, the ICTF could be mandated to promote the implementation of the Declaration. In addition, but not forming part of the Declaration, are reports of discussions held during the symposium on the governance of the nomenclature of fungi, and the naming of fungi known only from an environmental nucleic acid sequence in particular. Possible amendments to the Draft BioCode (2011) to allow for the needs of mycologists are suggested for further consideration, and a possible example of how a fungus only known from the environment might be described is presented

Replication Data for: Electrical Fields Induced Inside the Rat Brain with Skin, Skull, and Dural Placements of the Current Injection Electrode

Transcranial electrical stimulation (tES) is rapidly becoming an indispensable clinical tool with its different forms. Animal data are crucially needed for better understanding of the underlying mechanisms of tES. For reproducibility of results in animal experiments, the electric fields (E-Fields) inside the brain parenchyma induced by the injected currents need to be predicted accurately. In this study, we measured the electrical fields in the rat brain perpendicular to the brain surface, i.e. vertical electric field (VE-field), when the stimulation electrode was placed over the skin, skull, or dura mater through a craniotomy hole