IMMUNE SYSTEM

Immune System

Acquired Immunodeficiency Syndrome see AIDS
Addison's Disease
Adenoidectomy see Tonsils and Adenoids
Adenoids see Tonsils and Adenoids
Adult Immunization see Immunization
AIDS
AIDS and Infections
AIDS and Pregnancy
AIDS Medicines
AIDS--Living with AIDS
Allergy
Allergy, Food see Food Allergy
Allergy, Latex see Latex Allergy
Anaphylaxis see Allergy
Anatomy
Animal Bites
Ankylosing Spondylitis
Antimicrobial Resistance see Infectious Diseases
Asthma
Asthma in Children
Autoimmune Diseases
Bone Marrow Diseases
Bone Marrow Transplantation
Bronchial Asthma see Asthma
Coxsackievirus Infections see Viral Infections
Cryptosporidiosis
Childhood Asthma see Asthma in Children
Childhood Immunization
Childhood Leukemia see Leukemia, Childhood
Chronic Granulomatous Disease see Immune System and Disorders
Diabetes Type 1
EBV Infections see Infectious Mononucleosis
Epstein-Barr Virus Infections see Infectious Mononucleosis
Food Allergy
Glandular Fever see Infectious Mononucleosis
Hairy Cell Leukemia see Leukemia, Adult Chronic
Hay Fever see Allergy
HIV see AIDS
Hives
Hodgkin's Disease
Human Immunodeficiency Virus see AIDS
Immune System and Disorders
Immunization
Immunization, Childhood see Childhood Immunization
Infections, Viral see Viral Infections
Infectious Diseases
Infectious Mononucleosis
Insulin-Dependent Diabetes Mellitus see Diabetes Type 1
Juvenile Diabetes see Diabetes Type 1
Juvenile Rheumatoid Arthritis
Latex Allergy
Leukemia, Adult Acute
Leukemia, Adult Chronic
Leukemia, Childhood
Lupus
Lymph Nodes see Lymphatic Diseases
Lymphatic Diseases
Lymphedema see Lymphatic Diseases
Lymphoma
Milk Allergy see Food Allergy
Mononucleosis see Infectious Mononucleosis
Multiple Myeloma
Myelodysplastic Syndromes see Bone Marrow Diseases
Myeloproliferative Disorders see Bone Marrow Diseases
Non-Hodgkin's Lymphoma see Lymphoma
Nut Allergy see Food Allergy
Opportunistic Infections in AIDS see AIDS and Infections
Peanut Allergy see Food Allergy
Plasmacytoma see Multiple Myeloma
Pneumocystis Infections
Pregnancy and AIDS see AIDS and Pregnancy
Rheumatoid Arthritis
Roseola see Viral Infections
SCID see Immune System and Disorders
Scleroderma
Severe Combined Immunodeficiency see Immune System and Disorders
Sjogren's Syndrome
Spleen Diseases
Splenomegaly see Spleen Diseases
Spondylitis, Ankylosing see Ankylosing Spondylitis
Still's Disease see Juvenile Rheumatoid Arthritis
Swollen Glands see Lymphatic Diseases
Systemic Lupus Erythematosus see Lupus
Systemic Sclerosis see Scleroderma
Thymus Cancer
Tonsils and Adenoids
Tonsillectomy see Tonsils and Adenoids
Tonsillitis see Tonsils and Adenoids
Type I Diabetes see Diabetes Type 1
Urticaria see Hives
Vaccination see Immunization
Viral Infections
Yellow Fever see Viral Infections

EYE

Eyes and Vision

Age-Related Macular Degeneration see Macular Degeneration
AMD see Macular Degeneration
Anatomy
Astigmatism see Refractive Errors
Behcet's Syndrome
Blindness see Vision Impairment and Blindness
Cataract
Color Blindness
Conjunctivitis see Eye Infections
Contact Lenses see Eye Wear
Diabetic Eye Problems
Eye Cancer
Eye Diseases
Eye Infections
Eye Injuries
Eye Wear
Farsightedness see Refractive Errors
Floater see Retinal Disorders
Glasses see Eye Wear
Glaucoma
Hyperopia see Refractive Errors
Intraocular Melanoma see Eye Cancer
Laser Eye Surgery
LASIK see Laser Eye Surgery
Low Vision see Vision Impairment and Blindness
Macular Degeneration
Myopia see Refractive Errors
Nearsightedness see Refractive Errors
Nystagmus see Eye Diseases
Ophthalmology see Eye Diseases
Pink Eye see Eye Infections
Protective Eye Wear see Eye Injuries
Refractive Errors
Retinal Disorders
Retinoblastoma see Eye Cancer
Strabismus see Eye Diseases
Usher Syndrome
Vision Impairment and Blindness

ADSENSE

ADSENSE HAKKINDA YAPILMAMASI GEREKENLER

1-Asla pahalı kelime yazmayın. Pahalı kelimeden yastım tıklama fiyatları yüksek kelimeler. Tek tık için 1$ ve üzeri veren kelimeler (forex, student loan, mesothelioma, cancer drugs vs.vs... ) Elbetteki siteniz ingilizce olabilir. Hatta makale sitesi tavsiye ederim ...// Pahalı kelimeler yasarsanız çok güzel para kazanırsınız ama alamazsınız. Google reklamlarını bedava yayınlamış olursunuz. Hesabınıza yazık olur... Eskiden bu kadar çok denetim ve kontrol yoktu. belki o yüksek kazanç miktarlarını alırdınız ama artık kuş uçurtmuyorlar almanız imkansız...

2-Asla bir tane google adsense hesabına yoğunlaşmayın. Eğer sadece Google adsenseden para kazanmak amaçlı bir siteler açtıysanız kazancınız 1500$'ı aşmasın.(Hatta mümkün olduğunda kazançlarınızı hesaplara bölerek bu kazanç değerini 800$'a kadar çekin)

3-Asla Popup hit, frame hit basmayın.Bir çoğu google ziyaretçi hitini beklemez direk kullanıcıyı siteye başka yollardan çekerek kazanmak ister.Ancak bununda belli temel durumları vardır.Sayfanıza Banner yada text şeklinde olağan kullanıcı hiti çekiniz.Yani kimse sayfanıza zorunlu girmesin.Google sevmiyor çünkü.Bu önemli bir ayrıntı.

4-Asla frame ile ingilizce veyahut direk pahalı reklam çıkarmayın.Buda bi çeşit uyanıklık gibi duruyor ancak googlenin en sevmediği türlerden.Yani senin türkçe forumun vardır kalkar pahalı ve popüler reklamlar çıkarıyorsundur. Google salak değil, dünyanın en zeki mühendislerinin çalıştığı dev bir firma oldugunu asla unutmayın. Yapılmış ve yapılması muhtemel tüm hile yollarının önlemleri çoktan alındı. Sen sitenden tık başına 0,10 bile alamazken bir anda 0,7 - 1,0 gibi değerler alman olağan gelmez googleye.Belki bir ay alırsınız ancak 2.ci ay olmaz.Hatta google hesabıda banlamaz domaininizi banlar yazık olur.

5-Asla dolduruşa gelmeyin.Forumlarda gördüğünüz kazanç istatistikleri sizi yanıltmasın.Siz 250 dolar kazanıyorsunuzdur ayda ama hakkıyla hile yapmadan veya hile korkusu ile yaşamadan.Adam 2500 dolar kazanıyordur gidin bide ona sorun nasıl kazanıyorsun diye.Yinede tüm genellemeler yanlıştır.Ancak asla Yabancı kelime veyahut Pahalı kelime furyasına kapılmayın.Elinizdekinide kaybedersiniz.Kısacası her söylenene inanmayın ve dolduruşa gelmeyin. Altın yumurtlayan tavuğu kesmeyin...

6-Asla kullanıcıyı kandırmayın.Evet kullanıcının piskolojisi ile oynayabilirsiniz.Örneğin yazıların arasına oyun açılmadan önce yada videonun hemen altına yorum yazılan bölgenin hemen üstüne koyarak kullanıcıyı piskolojik olarak tıklamaya teşvik edebilirsiniz.Ancak Direkt olarak kullanıcıya reklama tıklamak zorundasın havası verirseniz vede bunu yazıyla yada simgelerle belirtirseniz google acımaz.Googlenin en sevmediği şeylerden biriside teşviktir.

7-Arkadaşlar Google reklam yayıncılarının haklarını korumak adına henüz en ufak bir girişimde bulunmadı. Sitenizi ziyaret eden bir ziyaretçi kıllığına bir reklama onlarca kez tıklarsa, geçersiz tıklama yaptınız diye hesabınızı kapatıyorlar. Sizde hakkınızı hiç bir şekilde savunamıyorsunuz.Bu kadar basit bir konunun önlemini bilmesine ragmen bir türlü hayata geçirmediler. Çünkü banlanan her kullanıcının içerde kalan parasının bir nevi üzerine yatıyorlar. Piyasaya başka dişli bir rakip girmedikçe bu işin böyle gidecegi çok açık....Bu sorun tek bizde degil, yurtdışındaki bir çok reklam yayıncısınında başında oldugundan bir grup programcı bu olaya kendi yazdıkları program ile çözüm bulmuşlar. Script kodunu adsense kullandıgınız her sayfanıza koymanız yeterli. Bir ziyaretçinin belirlediginiz tıklama adetiden fazla tıklamasına izin vermiyor. reklamları bloke ediyor. çıkartmıyor. Tüm bunlara ek olarak hangi ip adresi, hangi reklama tıkladı onuda takip edebiliyorsunuz. Geçersiz tık yapan düşmanlarınız veyahut insanlar olabilir.En azından bu tür bi olay için büyük ölçüde önlem almış olursunuz.

8-Birşeylerin garip gittiğini düşündüğünüzde (örneğin tıklama istatistiklerinizin ani fırlaması kazanç dengelerinin bozulması) veya yerleşimlerin hile kapsamına girip girmediği konusunda şüpheleriniz olduğunda mutlaka önceden googleye bildirin.Google sizin mailinizi bekliyor olacak.Çünkü iletişime önem veriyolar.Her konuda yardımcı olacaklardır.

9-Asla ama Asla kendi reklamlarınıza tıklamayın, Heleki aynı bilgisayardan hesabınızı kontrol ediyorsanız. Daha önce banlanmış bir kişinin bilgileri ile(adres telefon ad soyad vs.) tekrar başvurmayın. Daha önce kullandığınız bir banka hesabını eft bilgisi olarak tekrar kullanmayın.Tüm bunlar banlanma sebebi ve risk taşıyıcı unsurlardır.

AdSense

AdSense is an ad serving program run by Google. Website owners can enroll in this program to enable text, image and, more recently, video advertisements on their sites. These ads are administered by Google and generate revenue on either a per-click or per-thousand-impressions basis. Google is also currently beta-testing a cost-per-action based service.
Google utilizes its search technology to serve ads based on website content, the user's geographical location, and other factors. Those wanting to advertise with Google's targeted ad system may sign up through AdWords. AdSense has become a popular method of placing advertising on a website because the ads are less intrusive than most banners, and the content of the ads is often relevant to the website.
It currently uses JavaScript code to incorporate the advertisements into a participating site. If it is included on a site which has not yet been crawled by the Mediabot, it will temporarily display advertisements for charitable causes known as public service announcements (PSAs). (Note that the Mediabot is a separate crawler from the Googlebot that maintains Google's search index.)
Many sites use AdSense to monetize their content and some webmasters work hard to maximize their own AdSense income. They do this in three ways:
They use a wide range of traffic generating techniques including but not limited to online advertising.
They build valuable content on their sites which attracts AdSense ads which pay out the most when they get clicked.
They use copy on their websites that encourage clicks on ads. Note that Google prohibits people from using phrases like "Click on my AdSense ads" to increase click rates. Phrases accepted are "Sponsored Links" and "Advertisements".
The source of all AdSense income is the AdWords program which in turn has a complex pricing model based on a Vickrey second price auction, in that it commands an advertiser to submit a sealed bid (not observable by competitors). Additionally, for any given click received, advertisers only pay one bid increment above the second-highest bid

HEMODIALYSIS

It was intended to examine the properties of cellulosic and synthetic artificial kidney membranes in relation to hemodialysis and find out the changes in the materials features and performances after the treatment. Therefore, it was purposed to make recommendations about the appraisal of reusable or disposable membranes by means of comparative analyses. This study fulfilled the gap in the literature via its interdisciplinary approach by incorporating totally original approaches, the brand new results and novel experiments and clinical analyses that ascertain and resolve some of the disputed recent biocompatibility issues and questions related to dialysis via comparatively indicating the correlation between the complex reaction of the biological system with the treatment environment and the physical, chemical, thermal, mechanical, morphologic and transport properties of the membranes. The impacts of the first use on membranes were reported for the first time in this thesis. The data of the study revealed that membrane type, hematocrit level, pump speed, biostability, molecular and supramolecular structure of various dialysers can be as important as mere membrane-blood interaction in hemocompatibility.
By conducting Kt/V calculations and Statistical Analyses (ANOVA, Taguchi) on the selected patients, it was elucidated that the impact of the inevitable direct interactions among the chosen eight factors (dialysis age, dialyzer membrane material, hematocrit, interdialytic weight difference, dialysate type, pump speed, heparin type, socioeconomic status) on the treatment adequacy was more potent than that of the individual ones. The data acquisition from the patients with end-stage renal failure and measurement of the Kt/V values based on Daugirdas-2 formula were achieved through database software. As hypothesized in the construction of the linear graph, it was concluded that membrane type is the most effective individual component (F=11.96) among the predetermined eight factors on the treatment adequacy and patient well-being and that the performance of the polysulfone in the treatment is higher than that of cellulosic membranes. Consequently, the difference between cellulosic (two Hemophan and Cellulose Acetate and one kind of Cuprophan) and synthetic (Polysulfone) membranes were probed in terms of their physical and chemical properties, molecular and supramolecular structures (semi-crystalline or amorphous), mechanical behaviors, surface topography and morphologies (porous or dense). By realizing the changes in the membranes that occur due to single use, the appropriateness of reuse of membranes in some countries in the absence of standards was also questioned. To these ends, mechanical (simple tensile tests, stress relaxation experiments, load-unload tests, sudden strain rate change experiments), morphological (Scanning Electron Microscope: SEM, Atomic Force Microscope: AFM, optic and stereo microscopes), chemical (Electron Dispersive X-Ray Spectroscopy: EDXS, Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy: ATR-FTIR, Crosspolarization Magic Angle Spinning Solid State Nuclear Magnetic Resonance Spectroscopy: SSNMR), thermal (Differential Scanning Calorimetry: DSC, Thermogravimetric Analysis: TGA) and physical (Positron Annihilation Lifetime Spectroscopy: PALS, X-Ray Diffraction: XRD) tests were conducted on both used and virgin membranes. SSNMR indicated the change in the supramolecular structure; formation of crosslinking and chain scissioning and the mobility decrease in the cellulosic membranes after utilization. According to the results of NMR and PALS, utilized polysulfone can be statistically accepted equal to the unutilized one. According to the results of PALS pertaining to Cellulose Acetate it was verified that following utilization the membrane is exposed to both severe physical and chemical ageing due to constant t3 with the greatest variation in the I3 parameter. Although SSNMR indicated that both used hemophan and cuprophan retain their before-use chemical properties, through PALS it was unearthed that hemophan which reveals greater reduction in I3 is influenced more than cuprophan after use. The ATR-FTIR Spectroscopy documented that after use, while polysulfone maintains the same functional groups, amide is incorporated into cellulosic membranes. By FTIR it was proved that polysulfone is the least impaired membrane after use. After use, contrary to polysulfone, SSNMR verified moderate chemical and physical ageing in cuprophan and hemophan, and severe ageing in cellulose acetate but variation in the type and amount of crystallinity and mobility decrease in cuprophan, hemophan and cellulose acetate. The crystalline structures of the membranes were detailed by fibers’ XRD. The XRD diffractograms of the unused membranes mostly showed both sharp peak features corresponding to regions of 3D order and more diffuse patterns characteristic of molecularly disordered structures. It was revealed that atomic structure of the virgin cellulosic membranes has small-molecule impurities at the atomic or molecular level that locally strain the crystal structure appeared as well-defined broad peaks. Following use, in XRD patterns, polysulfone did not indicate a crucial difference in terms of type and amount of crystallinity and molecular distortions while the number of defects in cellulosic membranes were increased dramatically enough to saturate the structure and decreased local variation of local lattice spacing and this, in turn, reduced peak width proving change in the crystallinity. XRD concluded that percentage of crystalline and amorphous portions was impaired due to use and transport capacity of the cellulosic membranes deteriorated even after single use since diffusion takes place in the amorphous regions and their crystalline interfaces.
Decreases in tensile strength, strain/fracture values, toughness and increase in strain hardening were identified in the used membranes excluding polysulfone. Virgin membranes exhibited ductile failure, hard and tough plastic behaviour whereas their used ones failing at much shorter times and much lower loads showed brittle failure and weak profile except polysulfone that is tough in both conditions. Decreased molecular free volume, increased packing (physical ageing), and impurities in the used cellulosic membranes obviously resulted in reduced molecular mobility leading ductile to brittle transition. By DSC and TGA, virgin cellulosic membranes commenced degrading at lower temperatures as compared with used ones. SEM studies on the virgin cellulosic fibers showed dense, symmetric, homogeneous structure and rough fracture surface compatible with ductile mode of failure. However, in used cellulosic membranes, fractography presenting smooth surface accompanied by large tearings and discontinuities testified embrittlement and ageing. Cellulosic membranes becoming brittle after one-use should be expected to be more prone to develop cracks and fracture, thus complications including rupture and backtransport associated with the passage of contaminants from dialysate to blood in multiple uses. Pore geometry and distribution, surface topography and roughness of the membranes were detailed by AFM. Fractography of polysulfone exhibited asymmetric, dual-skinned, porous and ductile structure.
It is required to reduce the cost of dialysis since, due to an increase in the mean age of the general population, there will be a progressive increase in dialysis patient numbers with comorbidity most of who will not be suitable for renal transplantation. However, it is well recommended that polysulfone, which yields the best results in terms of performance and the preservation of material properties, should be prefered to cellulosic membranes as both reusable and disposable membrane. Since this study proved that even first use deteriorates the properties, quality and transport capacity of membranes, reuse should only be taken into agenda as long as reliable analyses on the candidate membranes are performed in advance. Otherwise, disposable use of the membranes is recommended

ALTITUDE SICKNESS

Diving at altitude requires different tables than at sea level due to the reduction in surface level ambient pressure. In this work, the rationale for the algorithms extrapolating the sea level diving data are reviewed. When applied to different sets of maximum permissible tissue tensions (M value), the conservatism of an algorithm becomes a function of bottom time, depth and altitude. Aviation altitude exposure decompression sickness (DCS) data is also addressed. Animal experiments performed within the scope of this thesis proved that precordial bubbles can form during the ascent from sea level to 2000-m. supporting a far lower threshold for altitude DCS then the model outputs.
Following three pioneering altitude diving expeditions to 2200, 3412 and 3980-m, a set of no-decompression stop (no-d) limits for 3500 m was calculated using linear extrapolation of US Navy M values decreased by 4 feet of sea water. This is a new method of altitude adaptation (NLHE, Nonlinear Hypobaric Extrapolation). These limits were tested at 3412-m. by 10 man/dive per profile without any case of DCS. 212 dives were achieved with a total bottom time of 4110 min. The mean DCS risk estimated according to precordial bubble scores (Spencer’s Scale) ranges from 0.3% to 2.8% per profile.
The last part of the thesis is devoted to the computation of decompression tables for 3500-m altitudes. This work suggests the use of a continuous variable for the compartment time constants, allowing the simulation of infinite number of compartments and reducing the discrepancy between different algorithms to a single M value expression.
New knot configurations, consisting of alternating strands with different patterns, have been studied from mechanical and biological perspectives in order to determine whether they would be suitable for abdominal surgery, as compared with conventional sliding knots. Mechanical properties of these new knots were compared with those of the classical sliding knots and single threads for silk and nylon sutures under dry conditions. From the mechanical perspective, the new knots showed better knot holding capacity and efficiency. In the in vivo implantation tests performed on the rat abdominal wall, the alternating sliding knots with different patterns were found to be more efficient and secure than the classical sliding knots. The knot configuration, postoperative period, suture material and size were important factors in determining the knot holding capacity. From the biological perspective, these new knots provoked tissue reaction similar to the classical sliding knots. Because nylon is less pliable than silk, its use resulted in higher effective knot volumes, causing more pronounced tissue reaction. To test the bacterial adherence to the knots, in vitro and in vivo tests were performed in rats. The degree of the elicited infection correlated well with the capability of bacteria to bind to the suture. It was observed that the knot configurations and the suture sizes did not have much effect on bacterial adherence. Due to the presence of interstices between throws, the knots had greater capacity to retain bacteria than the single threads for both silk and nylon, thus promoting infection. The elasticity and stress-relaxation properties of these knots were compared to those of single threads of silk and nylon. The elasticity of the knots, in general, was higher than that of the threads for both materials. The silk showed decreased elasticity at high extension levels, while nylon showed increased elasticity. In stress relaxation tests, the residual load fraction of the knots was found to be higher than that of the threads at all extension levels. A model was created to study the effect of several factors on the suture pullout force in the abdominal wall. Incisional direction, knot configuration, strain rate and tissue healing strength were important factors in determining the suture pullout force. In conclusion, we do recommend the use of the alternating sliding knots with different patterns in abdominal surgery instead of the currently used sliding knots

DENTISTRY

In this study possible applications of bioceramics like hydroxyapatite (HA) and bioglass in dentistry have been studied. HA was derived from freshly extracted human teeth in laboratory conditions as plasma coating and grafting material and basic techniques for material characterization were performed. The HA produced by this method is simple and economical when compared with conventional methods which are mtedious and time consuming. Bioglass compositions used in this study, were produced from reagent grade fine chemicals and some porous structures were prepared. Implant prototypes prepared from titanium rods, were coated with HA powder using a plasma coating unit.
The HA produced by this method has been demonstrated to have the potential to become a superior graft material in veterinary orthopedics. Plasma spraying studies agreed with the results in the literature. Pathological results of the animal studies have been affirmative. For animals nuclear bone scintigraphy studies were performed to follow the osseointegration process in HA/ bioglass grafting cases. It was observed that bone scintigraphy was a valuable method to follow the metabolic activity of bone cells when compared with planar X-ray films.
Graft studies were also performed using plaster of Paris which is another bioceramic. An active drug delivery system was evaluated based on its rapid solubility characteristics. Pathological results and high performance liquid chromatography results indicated that this material has potential as a drug delivery system

KARIN YARALARI

KARIN YARALARININ KAPANMASINDA FARKLI BİÇİMLİ KAYAN DÜĞÜMLERİN MEKANİK VE BİYOLOJİK DAVRANIŞI
Karın cerrahisinde, klasik kayan düğümlere kıyasla daha uygun olup olmadıklarını belirleyebilmek için farklı biçimli, yer-değiştirmeli kayan düğümlerden oluşan yeni düğüm biçimleri mekanik ve biyolojik yönden incelendi. Kuru koşullarda, ipek ve naylondan yapılan tek iplik ve düğümler için, bu yeni düğümlerin mekanik özellikleri klasik kayan düğümlerle karşılaştırıldı. Mekanik açıdan, yeni düğümlerin düğüm tutma kapasitelerinin ve verimlerinin daha iyi olduğu gösterildi. Sıçan karın duvarında yapılan "in vivo" implantasyon testlerinde, farklı biçimli kayan düğümlerin klasik kayan düğümlerden daha verimli ve daha güvenli olduğu saptandı. Düğüm biçimi, cerrahiden sonra geçen zaman, cerrahi ip materyali ve çap düğüm tutma kapasitesini belirleyen önemli faktörlerdi. Biyolojik yönden bu yeni düğümlerin klasik kayan düğümlerle aynı doku reaksiyonuna yol açtıkları görüldü. Naylon ipek kadar yumuşak olmadığından, naylon iple yapılan düğümlerin etkin hacimlerinin daha büyük olduğu, ve bu nedenle de daha belirgin doku reaksiyonuna sebep oldukları saptandı. Düğümlere bakteri yapışmasını test etmek için sıçanlarda "in vivo" ve "in vitro" testler yapıldı. Oluşan enfeksiyon bakterinin ipliğe yapışabilme kapasitesiyle orantılı bulundu. Düğüm biçimi ve iplik çapının bakteri yapışmasında etkili bir rol almadığı gözlemlendi. Hem ipek hem de naylon için, bağlar arasındaki boşluklar nedeniyle düğümlerin bakteri tutma kapasitelerinin tek ipten daha fazla olduğu bulundu. İpek ve naylon için, yeni düğümlerle tek ipliklerin esneme ve gerilim-gevşeme özellikleri karşılaştırıldı. Genel olarak, düğümlerin esneme yeteneklerinin tek ipliklerden daha yüksek olduğu saptandı. Yüksek uzama düzeylerinde, ipek ip ve düğümlerin esneme yeteneklerinde azalma görülürken, naylonda artma görüldü. Gerilim gevşemesi testlerinde, tüm uzama düzeyleri için, kalan yük fraksiyonunun, düğümlerde iplerden daha fazla olduğu bulundu. Çeşitli faktörlerin, karın duvarında ip çekilme kuvveti üzerindeki etkilerini incelemek amacıyla bir model geliştirildi. Kesme yönü, düğüm biçimi, gerilme oranı ve doku iyileşme gücü ipin çekilme kuvvetini belirleyen önemli faktörlerdi. Sonuç olarak, karın ameliyatlarında, halen kullanılmakta olan kayan düğümler yerine farklı biçimli kayan düğümlerin kullanılması önerilmektedir
New knot configurations, consisting of alternating strands with different patterns, have been studied from mechanical and biological perspectives in order to determine whether they would be suitable for abdominal surgery, as compared with conventional sliding knots. Mechanical properties of these new knots were compared with those of the classical sliding knots and single threads for silk and nylon sutures under dry conditions. From the mechanical perspective, the new knots showed better knot holding capacity and efficiency. In the in vivo implantation tests performed on the rat abdominal wall, the alternating sliding knots with different patterns were found to be more efficient and secure than the classical sliding knots. The knot configuration, postoperative period, suture material and size were important factors in determining the knot holding capacity. From the biological perspective, these new knots provoked tissue reaction similar to the classical sliding knots. Because nylon is less pliable than silk, its use resulted in higher effective knot volumes, causing more pronounced tissue reaction. To test the bacterial adherence to the knots, in vitro and in vivo tests were performed in rats. The degree of the elicited infection correlated well with the capability of bacteria to bind to the suture. It was observed that the knot configurations and the suture sizes did not have much effect on bacterial adherence. Due to the presence of interstices between throws, the knots had greater capacity to retain bacteria than the single threads for both silk and nylon, thus promoting infection. The elasticity and stress-relaxation properties of these knots were compared to those of single threads of silk and nylon. The elasticity of the knots, in general, was higher than that of the threads for both materials. The silk showed decreased elasticity at high extension levels, while nylon showed increased elasticity. In stress relaxation tests, the residual load fraction of the knots was found to be higher than that of the threads at all extension levels. A model was created to study the effect of several factors on the suture pullout force in the abdominal wall. Incisional direction, knot configuration, strain rate and tissue healing strength were important factors in determining the suture pullout force. In conclusion, we do recommend the use of the alternating sliding knots with different patterns in abdominal surgery instead of the currently used sliding knots