Design of a Mars Rover suspension mechanism

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2004Includes bibliographical references (leaves: 71-75)xiii, 75 leavesIt is obvious that rovers are important vehicles of today.s solar system exploration. Most of the rover designs have been developed for Mars and Moon surface in order to understand the geological history of the soil and rocks. Exploration operations need high speed and long distance traversal in a short mission period due to environmental effects, climate and communication restrictions. Several mechanisms have been suggested in recent years for suspensions of rovers on rough terrain. Although their different mechanisms have found a widespread usage in mobile robotics, their low operation speed is still a challenging problem. In this research, a new suspension mechanism has been designed and its kinematic analysis results were discussed. Standard rocker-bogie suspension mechanism, which has been developed in the late 1990.s, has excellent weight distribution for different positions on rough terrain. New design, mostly similar to rocker-bogie suspension system, has a natural advantage with linear bogie motion which protects the whole system from getting rollover during high speed operations. This improvement increases the reliability of structure on field operations and also enables the higher speed exploration with same obstacle height capacity as rocker-bogie. In this thesis study, new bogie mechanism consisted of double-lambda mechanisms, which has been firstly presented by Pafnuty Lvovich Chebyshev in 1869, is solved by analytically to define the positions and singular configurations. A new structural synthesis formula also has been introduced for such suspension mechanisms with lower and higher kinematic pairs. By using structural synthesis methods, a suspension mechanism has been designed with double-lambda mechanism. Equivalent force and moment functions were also derived with equation of motion method. The results are confirmed with the computer analysis made by Visual Nastran 4D®. For this purpose, a computer model has been constructed and assembled with the same design parameters of NASA Mars Exploration Rovers (MER1 and MER2)

Design of a Mars Rover suspension mechanism

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2004Includes bibliographical references (leaves: 71-75)xiii, 75 leavesIt is obvious that rovers are important vehicles of today.s solar system exploration. Most of the rover designs have been developed for Mars and Moon surface in order to understand the geological history of the soil and rocks. Exploration operations need high speed and long distance traversal in a short mission period due to environmental effects, climate and communication restrictions. Several mechanisms have been suggested in recent years for suspensions of rovers on rough terrain. Although their different mechanisms have found a widespread usage in mobile robotics, their low operation speed is still a challenging problem. In this research, a new suspension mechanism has been designed and its kinematic analysis results were discussed. Standard rocker-bogie suspension mechanism, which has been developed in the late 1990.s, has excellent weight distribution for different positions on rough terrain. New design, mostly similar to rocker-bogie suspension system, has a natural advantage with linear bogie motion which protects the whole system from getting rollover during high speed operations. This improvement increases the reliability of structure on field operations and also enables the higher speed exploration with same obstacle height capacity as rocker-bogie. In this thesis study, new bogie mechanism consisted of double-lambda mechanisms, which has been firstly presented by Pafnuty Lvovich Chebyshev in 1869, is solved by analytically to define the positions and singular configurations. A new structural synthesis formula also has been introduced for such suspension mechanisms with lower and higher kinematic pairs. By using structural synthesis methods, a suspension mechanism has been designed with double-lambda mechanism. Equivalent force and moment functions were also derived with equation of motion method. The results are confirmed with the computer analysis made by Visual Nastran 4D®. For this purpose, a computer model has been constructed and assembled with the same design parameters of NASA Mars Exploration Rovers (MER1 and MER2)

Teranostik gadolinyum nanoparçacıkların tasarımı ve in vitro uygulamaları

Teranostik tedavi, kanser araştırmalarında eş zamanlı görüntüleme ile tedaviye aynı anda izin veren son yılların en umut vaadetmekte olan yöntemlerinden biridir. Bu çalışmada gadolinyum nanopartiküller (GdNp) ve protoporfirin IX'lar (PpIX) aynı anda yüksek kimyasal stabilite ve enkapsülasyon verimine sahip olan niozomlar ile enkapsüle edilerek (Gd-PpIX-Ni) yeni bir teranostik tedavi ajanı oluşturuldu. GdNP ve PpIX'ların iyi birer radyoterapi (RT) yoğunlaştırıcı ajan oldukları bilinmektedir. Aynı zamanda porfirin türevleri en çok çalışılan fotodinamik terapi (FDT) ajanlarındandırlar. Yapmış olduğumuz araştırmada insan tip II alveolar (ATII) akciğer kanserli epitel hücre hatları (A549), insan kanserli yumurtalık hücre hatları (HeLa) ve insan sağlıklı akciğer epitel hücre hatları (WI38) üzerinde RT ve FDT'nin kombine uygulamaları (multimodal treatment) denenmiş ve hücre görüntüleri manyetik rezonans (MR) cihazı ve floresans mikroskop altında (dual imaging) alındı. Boyut ve zeta potansiyel bağımlı karakterizasyon çalışmaları dinamik ışık saçılımı metodu (DLS) ve atomik kuvvet mikroskopu (AFM) ile yapılmış olup çalışma boyunca hücre canlılığı MTT metodu ile ölçüldü. Sonuç olarak hazırlanmış olunan 100 nm'den daha küçük partikül boyutuna sahip teranostik niozomal veziküllerin kanser için yeni bir bakış açısı olan kombine tedavi ve çoklu görüntüleme çalışmalarının aynı anda yapılmasına olanak sağlayan uygun bir kargo sistemi olabileceği kanaatine varıldı.Theranostic therapy is one of the most promising technology in cancer research, which simulteniously allows treating and real-time monitoring of cancer. In the present study, a novel material has been developed for theranostic approach. Gadolinium nanopArticles (GdNP) and Protoporphyrin IX (PpIX) both have encapsulated with niosomes (Gd-PpIX-Ni). Here nisome has been used for the encapsulation of Gd-PpIX-Ni due to the fact that nisomes possess high biocompatiblity, physical and chemical stability. GdNp and PpIX are good sensitizer for radio therapy (RT) and PpIX is one of the more studied agent for photodynamic therapy (PDT). Treatment was performed by the combination of PDT and RT, by using human alveolar type-II (ATII)-like cell lines (A549), human cervical cancer cell line (HeLa) and Human alveolar epithelium cell line (WI38). Cell lines were monitored by fluorescence microscopy and magnetic resonance imaging (MRI). Characterization of sizes and zeta potential of vesicles were carried out by dynamic light scattering (DLS) and atomic force microscopy (AFM). MTT method was used viability of cell. Our results showed that Gd-PpIX-Ni are homegenious and consistent less than 100 nm. In conclusion, Gd-PpIX-Ni can be considered as good candidates to for PDT and RT treatment in theranostic approches

Caffeic acid phenethyl ester protects lung alveolar epithelial cellsfrom cigarette smoke-induced damage

Background/aim: To evaluate the influence of caffeic acid phenethyl ester (CAPE) on cigarette smoke (CS)-induced cell damage, oxidative stress, and inflammation in human alveolar epithelial cells. Materials and methods: A549 alveolar epithelial cells were divided into control, CS exposure, CAPE, and CS+CAPE treatment groups. Undiluted CS-exposed medium (100%) and three dilutions (50%, 25%, and 10%) of CS-exposed media were applied to cultured A549 cells, which were analyzed after 3 h of incubation. Viability was measured by MTT assay, the gene expressions were evaluated by real-time PCR, and spectrophotometric techniques were used for biochemical assessments. Results: While CS exposure markedly reduced cellular viability by 32% after 3 h of incubation, 2.5 µM CAPE treatments prevented CS-induced cell death by 40% in the cells. CS exposure triggered lipid peroxidation and depleted antioxidant capacity through inhibiting catalase activity and depleting glutathione levels. Moreover, CS increased nitric oxide production via upregulation of iNOS expression. CAPE treatment significantly restored antioxidant capacity and prevented lipid peroxidation. Cigarette smoke exposure induced inflammation by significantly upregulating TNF-?, IL-1ß, and COX-2 mRNA expressions (3-, 2- and 25-fold, respectively). CAPE treatment of A549 cells significantly reversed the inflammation. Conclusion: CAPE may potentially represent a new therapeutic option in the prevention of CS-induced lung damages.Background/aim: To evaluate the influence of caffeic acid phenethyl ester (CAPE) on cigarette smoke (CS)-induced cell damage, oxidative stress, and inflammation in human alveolar epithelial cells. Materials and methods: A549 alveolar epithelial cells were divided into control, CS exposure, CAPE, and CS+CAPE treatment groups. Undiluted CS-exposed medium (100%) and three dilutions (50%, 25%, and 10%) of CS-exposed media were applied to cultured A549 cells, which were analyzed after 3 h of incubation. Viability was measured by MTT assay, the gene expressions were evaluated by real-time PCR, and spectrophotometric techniques were used for biochemical assessments. Results: While CS exposure markedly reduced cellular viability by 32% after 3 h of incubation, 2.5 µM CAPE treatments prevented CS-induced cell death by 40% in the cells. CS exposure triggered lipid peroxidation and depleted antioxidant capacity through inhibiting catalase activity and depleting glutathione levels. Moreover, CS increased nitric oxide production via upregulation of iNOS expression. CAPE treatment significantly restored antioxidant capacity and prevented lipid peroxidation. Cigarette smoke exposure induced inflammation by significantly upregulating TNF-?, IL-1ß, and COX-2 mRNA expressions (3-, 2- and 25-fold, respectively). CAPE treatment of A549 cells significantly reversed the inflammation. Conclusion: CAPE may potentially represent a new therapeutic option in the prevention of CS-induced lung damages

Koroner arter bypass cerrahisinde ramiprilin miyokardiyal hasar ve inflamatuvar yanıttaki etkisi üzerinde sitokin gen polimorfizmlerinin rolü

Purpose: Ramipril is effective in treating inflammatory myocardial injury by reducing cytokines such as TNF-?, IL-6, and IL-8. In this study, we investigated the effect of cytokine gene polymorphisms on inflammatory response which might be reduced by ramipril. Material and Methods: Of 102 patients undergoing on-pump coronary artery bypass grafting surgery, 51 were the treatment group which received ramipril and the remaining 51 were the non-treated control group. TNF-?, IL-6, and IL-8 were measured with Enzyme-Linked Immuno Sorbent Assay (ELISA), before anesthesia induction (t1), at 20 min following cross clamping (t2), at the end of the operation (t3), and 24 hours after anesthesia (t4). Genotyping was performed with PCR method. Results: While TNF-? increase began with surgery, IL-6 and IL-8 increase began with cardiac arrest during cardiopulmonary bypass and continued until the end of the operation. In contrast, only IL-8 remained high in the control group during the postoperative period, while TNF-?, IL-6, and IL-8 began to decrease. The decreases in IL-6 at t3 and in TNF-? at t4 were significant. Conclusion: Ramipril might have a role in preventing inflammatory myocardial injury by reducing cytokine and TnT levels after cardiac arrest.Amaç: Ramipril, inflamatuar miyokardial hasarın tedavisinde TNF-?, IL-6 ve IL-8 gibi sitokin seviyelerini azaltarak etkili olmaktadır. Çalışmamızda, ramipril tedavisinin, koroner arter bypass cerrahisi esnasında oluşan inflamatuar yanıt ve miyokardiyal hasara yönelik etkisi üzerinde, sitokin gen polimorfizmlerinin herhangi bir rolü olup olmadığını araştırdık. Gereç ve Yöntem: Çalışmamıza, koroner arter bypass cerrahisi uygulanan hastalardan cerrahi öncesi ramipril alan 51, kontrol grubu olarak ise ramipril almayan 51 olmak üzere toplam 102 hasta dahil edildi. Her iki grupta, anestezi başlamadan hemen önce (t1), kros klemp sonrası 20. dakikada (t2), ameliyatın sonunda (t3) ve anestezinin başlangıcından 24 saat sonra (t4) alınan kan örneklerinden TNF?, IL-6, IL-8 ve TnT serum düzeyleri ELISA yöntemi ile, genotipleme ise PCR-RFLP yöntemleri ile belirlendi. Bulgular: Her iki grupta TNF-? artışı cerrahi ile başlarken, IL-6 ve IL-8 artışı kardiyopulmoner bypass sırasında kardiyak arrestle başlayıp ameliyat sonuna kadar devam etmiştir. Postoperatif dönemde ise sadece IL-8 kontrol grubunda yüksek kalırken; çalışma grubunda TNF-?, IL-6, IL-8 düşüşe geçmektedir. t3 zaman aralığında IL-6, t4 zamanında TNF? değerlerinde anlamlı azalma gözlenmiştir. Sonuç: Ramiprilin kardiyak arrest sonrası sitokin ve TnT düzeylerini azaltarak inflamatuar miyokardiyal hasarı önlemede yeri olabilir

Role of cytokine gene polymorphisms on ramipril-altered inflammatory response and myocardial injury in patients undergoing coronary artery bypass surgery

Amaç: Ramipril, inflamatuar miyokardial hasarın tedavisinde TNF-?, IL-6 ve IL-8 gibi sitokin seviyelerini azaltarak etkili olmaktadır. Çalışmamızda, ramipril tedavisinin, koroner arter bypass cerrahisi esnasında oluşan inflamatuar yanıt ve miyokardiyal hasara yönelik etkisi üzerinde, sitokin gen polimorfizmlerinin herhangi bir rolü olup olmadığını araştırdık. Gereç ve Yöntem: Çalışmamıza, koroner arter bypass cerrahisi uygulanan hastalardan cerrahi öncesi ramipril alan 51, kontrol grubu olarak ise ramipril almayan 51 olmak üzere toplam 102 hasta dahil edildi. Her iki grupta, anestezi başlamadan hemen önce (t1), kros klemp sonrası 20. dakikada (t2), ameliyatın sonunda (t3) ve anestezinin başlangıcından 24 saat sonra (t4) alınan kan örneklerinden TNF?, IL-6, IL-8 ve TnT serum düzeyleri ELISA yöntemi ile, genotipleme ise PCR-RFLP yöntemleri ile belirlendi. Bulgular: Her iki grupta TNF-? artışı cerrahi ile başlarken, IL-6 ve IL-8 artışı kardiyopulmoner bypass sırasında kardiyak arrestle başlayıp ameliyat sonuna kadar devam etmiştir. Postoperatif dönemde ise sadece IL-8 kontrol grubunda yüksek kalırken; çalışma grubunda TNF?, IL-6, IL-8 düşüşe geçmektedir. t3 zaman aralığında IL-6, t4 zamanında TNF? değerlerinde anlamlı azalma gözlenmiştir. Sonuç: Ramiprilin kardiyak arrest sonrası sitokin ve TnT düzeylerini azaltarak inflamatuar miyokardiyal hasarı önlemede yeri olabilir.Purpose: Ramipril is effective in treating inflammatory myocardial injury by reducing cytokines such as TNF-?, IL-6, and IL-8. In this study, we investigated the effect of cytokine gene polymorphisms on inflammatory response which might be reduced by ramipril. Material and Methods: Of 102 patients undergoing onpump coronary artery bypass grafting surgery, 51 were the treatment group which received ramipril and the remaining 51 were the non-treated control group. TNF-?, IL-6, and IL-8 were measured with Enzyme-Linked Immuno Sorbent Assay (ELISA), before anesthesia induction (t1), at 20 min following cross clamping (t2), at the end of the operation (t3), and 24 hours after anesthesia (t4). Genotyping was performed with PCR method. Results: While TNF-? increase began with surgery, IL-6 and IL-8 increase began with cardiac arrest during cardiopulmonary bypass and continued until the end of the operation. In contrast, only IL-8 remained high in the control group during the postoperative period, while TNF-?, IL-6, and IL-8 began to decrease. The decreases in IL-6 at t3 and in TNF-? at t4 were significant. Conclusion: Ramipril might have a role in preventing inflammatory myocardial injury by reducing cytokine and TnT levels after cardiac arrest

A multi-functional fluorescent scaffold as a multi-colour probe: design and application in targeted cell imaging

A novel scaffold material based on a novel targeting strategy has been developed, benefiting from recent progress in the development of fluorescent bioprobes. This concept suggests that several specifications which are desired for cancer cell targeting and imaging studies can be satisfied at the same time in one multifunctional scaffold. Besides, such scaffolds exhibit multi-colour properties when combined with a targeting moiety. For this purpose, a fluorescent and functional monomer, 3-(1H-phenanthro[9,10-d]imidazol-2-yl)phenol (PIP) and an antibody labelling kit (CF555) were merged on the same scaffold to generate the proposed bioprobe. This design offers multicolour cell images by emitting at dual wavelengths with no quenching in its fluorescent property. Also, pendant alcohol groups in the structure of PIP enable covalent attachment to labelled protein, CF555/anti-CD44 in order to enhance the biological activity and specificity towards the target. After combining with the targeting moiety, the bioconjugate was characterized, tested for in vitro studies, and the cellular internalization was monitored in live cells via the fluorescence microscope technique. The present work with such a strategy explores the potential use of the proposed fluorescent probe for the first time. The aim is to achieve targeted imaging of CD44 positive U87-MG cancer cells and determine specific cellular labelling via fluorescence imaging and flow cytometry experiments