Can diffusion-weighted imaging be used in the examination of peritoneal fluids?

Purpose: The aetiology of free fluid detected in the abdomen can be investigated with magnetic resonance imaging (MRI). The aim of this study is to investigate the effectiveness of diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) values in the evaluation of abdominopelvic fluids. Material and methods: Patients with abdominopelvic fluid detected on MRI of the lower abdomen were included in this retrospective, single-centre study. Paracentesis and fluid analysis was performed in these patients. The average ADC values in fluids were measured by a radiologist. A cut-off value was determined, and the specificity, sensitivity, negative predictive value (NPV), and positive predictive values (PPV) were calculated. Intra-observer agreement was investigated. Results: The study comprised 41 (33 female) patients, and their mean age was 48 ± 4.02 years. The ADC values in infective fluids were significantly higher than in non-infective fluids (p < 0.001). The cut-off value used was 2.95 × 10-3 mm²/s. According to this threshold value, sensitivity in distinguishing non-infective from infective fluids was 88%, specificity was 93.8%, PPV was 95.7%, and NPV was 83.3%. Intra-observer agreement was strong in ADC values (κ = 0.699) (p < 0.001). Conclusions: We concluded that the ADC value is a non-invasive, reliable, reproducible imaging parameter that can be useful in the evaluation and characterization of abdominal fluids

An investigation of the efficacy of shear wave elastography in the characterization of benign and malignant liver lesions

Purpose: To investigate whether shear wave elastography (SWE) examination, which has recently been proposed as an accessory radiological examination technique, is effective in characterizing focal liver lesions (FLLs). Material and methods: A total of 105 patients, comprising 48 males and 57 females, underwent SWE examination. The mean age of the patients was 53.31 ± 1.59 (age range 5-87) years. The SWE measurements were obtained from FLLs that were approximately 2 to 8 cm in depth in a box that was approximately 0.5 × 1 cm wide on an ultra sonography (USG) screen from approximately 2 different locations. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic SWE values in the differentiation of benign and malignant lesions. Sensitivity, specificity, and positive predictive and negative predictive values were calculated in the presence of significant limit values. Results: The SWE values, in kPa and m/s, in the malignant lesions were significantly higher than those in the benign lesions (p = 0.006, p = 0.011). In the ROC curve analysis, the cut-off value was calculated as 9.005 kPa in the differ entiation of malignant lesions from benign lesions. The area under the ROC curve was calculated as 0.656 in the range of 0.551-0.761 with 95% reliability. Sensitivity was calculated as 64.2%, specificity as 61.5%, positive predictive value as 63%, and negative predictive value as 62.7%. Conclusions: In addition to providing little contribution to the differentiation of benign and malignant lesions, the SWE technique is thought to contribute to a certain extent, especially in suspected cases, during the diagnosis with cross sectional methods

Computational Screening of MOF-Based Mixed Matrix Membranes for CO 2

Atomically detailed simulations were used to examine CO2/N2 separation potential of metal organic framework- (MOF-) based mixed matrix membranes (MMMs) in this study. Gas permeability and selectivity of 700 new MMMs composed of 70 different MOFs and 10 different polymers were calculated for CO2/N2 separation. This is the largest number of MOF-based MMMs for which computational screening is done to date. Selecting the appropriate MOFs as filler particles in polymers resulted in MMMs that have higher CO2/N2 selectivities and higher CO2 permeabilities compared to pure polymer membranes. We showed that, for polymers that have low CO2 permeabilities but high CO2 selectivities, the identity of the MOF used as filler is not important. All MOFs enhanced the CO2 permeabilities of this type of polymers without changing their selectivities. Several MOF-based MMMs were identified to exceed the upper bound established for polymers. The methods we introduced in this study will create many opportunities to select the MOF/polymer combinations with useful properties for CO2 separation applications

Investigating the effect of daylight on seating preferences in an open-plan space: A comparison of methods

As a dynamic element revealing architectural space, daylight not only provides substantial illumination but may also influence how occupants interact with the space. This thesis investigates one aspect of interaction, whether there is an effect of daylight on seat choice behaviour. Previous studies have provided limited evidence of an association between daylight and seating preferences of individuals, in part because each study employed different methods to measure and quantify seating preferences of individuals. This concern is compounded by the fact that previous research has tended to use a unique set of daylight metrics in addition to a unique set of measurement points in the test space. This raises the discussion as to the method by which daylighting conditions were evaluated and the procedure with which seating preferences were sought. This study used two procedures to examine whether daylight affects seating preferences in an open plan room. The first was a stated preference approach in which individuals were asked to indicate the factors they perceived to influence their choice of seat location. Responses were sought from both those who were about to enter the room and those who were already seated in the room. Daylight was suggested to be the most important factor amongst those respondents already seated in the room, but was less important among those people who responded at the entrance. The second was a revealed preference approach which draws inferences on seating preferences from the actual choices made by individuals in the test room. The data were collected using two methods. One was a snapshot method, recording actual seating behaviour of individuals at regular intervals and the other was a walk-through method, following individuals from the moment they entered the room until they chose a seat. The influence of daylight was investigated using a dynamic simulation modelling method to predict daylight illuminance in the test space. The method was to derive a set of daylight metrics for each individual seat over the observation period. Results showed that higher illuminances led to increased seat occupancy, but only in close proximity to windows. It was found that using a questionnaire to ask people about their seat choice when already seated led to the suggestion that daylight had stronger influence than was found in the revealed preference approach

Contribution of mesenchymal stem cells in cell based therapies

Ankara : The Department of Molecular Biology and Genetics and the Institute of Engineering and Science of Bilkent University, 2010.Thesis (Ph. D.) -- Bilkent University, 2010.Includes bibliographical references leaves 73-106.tem cell research evolved as a new hope and has gained tremendous interest in the last two decades to develop new strategies for many of debilitating diseases. Mesenchymal Stem Cells (MSCs) are multipotent cells capable of self-renewal and differentiating into multiple lineages such as osteocytes, adipocytes, chondrocytes, myoblasts, and hepatocytes. MSCs can migrate to the injured tissue and have immunomodulatory effects. Due to these features, MSCs have high therapeutic value in tissue engineering and regenerative medicine. In this thesis, our aim was to investigate the further contribution of the MSCs in different cellular therapies. We used two approaches to accomplish our aim. First, we investigated the possibility of obtaining functional cardiomyocytes from rat MSC within a shorter time period by determining the induction timing of cardiomyocyte differentiation of MSCs. Our data revealed that it is possible to get functional cardiomyocytes from in vitro MSC culture in a shorter time period than previously achieved. This reduction in time may provide emergency cases with access to cell-based therapies that may have previously been unavailable. In the second part of this thesis, we examined in vivo and in vitro effects of a telomerase antagonist, imetelstat (GRN163L) on MSCs. Telomerase activity is essential for the continued growth and survival of malignant cells, therefore inhibition of this activity presents an attractive target for anti-cancer therapy. MSCs also show telomerase activity in maintaining their self-renewal; therefore the effects of telomerase inhibitors on MSCs may be an issue of concern. Our results showed that inhibiting the telomerase activity does not interfere with the self-renewal and differentiation of MSCs under short term in vitro culture conditions.Keskin, Zeynep TokcaerPh.D

Morphometric risk factors effects on anterior cruciate ligament injury

Objectives: This study aims to compare the morphometric differences between patients with and without an anterior cruciate ligament (ACL) injury and to investigate the anatomical risk factors associated with ACL injury. Patients and methods: Between February 2020 and February 2022, a total of 100 patients (57 males, 43 females; mean age: 36.2 +/- 6.8 years; range, 18 to 45 years) who were operated for isolated non-contact ACL tear as the patient group and a total of 100 healthy individuals (58 males, 42 females; mean age: 35.0 +/- 6.9 years; range, 18 to 45 years) without an ACL tear as the control group were included. Magnetic resonance imaging scans of the knee joint were included in the study. Morphological variables of the ACL, distal femur, proximal tibia, and menisci were measured. Results: The mean ACL inclination angle and medial meniscus bone angle were 37.7 +/- 3.8 and 20.2 +/- 2.9 in the patient group and 48.1 +/- 3.3 and 25.0 +/- 2.9 in the control group. According to the results of multivariate analysis, those with small ACL inclination angle and medial meniscus bone angle were more likely to have ACL tear (odds ratio: 0.128, intraclass correlation coefficient: 0.038-0.430, p= 0.001). Conclusion: Small ACL inclination angle and medial meniscus bone angle can be a risk factor for ACL tear

Administration of bone marrow derived mesenchymal stem cells modulate tlr expression during liver regeneration

Liver cell transplantation is a powerful alternative to orthotopic cell transplantation in the treatment of liver failures. Recently, considerable effort is being channeled to understand the nature and kinetics of directing stem cells to effectively accumulate at the regenerating liver site. Mesenchymal stem cells are one of the promising cell sources modulating liver regeneration process. The present was designed to study how mesenchymal stem cells might modulate liver immune behaviors by changing Toll-like receptor (TLR) expression and increase regenerative potential during liver regeneration in rats. Normal and partially hepatectomized rats were treated with mesenchymal stem cells isolated and expanded from rat bone marrows. Accumulation of mesenchymal stem cells was confirmed by Real Time-Polymerase Chain Reaction (RT-PCR), Fluorescence-Activated Cell Sorting (FACS), and Immunofluorescence Staining (IFS). Student's t-test analysis was used to evaluate the significance of differences between sham and partially hepatectomized rat groups. Our results showed that mesenchymal stem cells expressed several TLRs, and their accumulation during regeneration was depended on the timing of injury. Mesenchymal stem cells isolated from bone marrow of normal rats were observed at the injured liver 3 days after the injection. There were no labeled mesenchymal stem cells in the liver sections of the uninjured animals. Mesenchymal stem cell administration significantly altered the expression of TLR2, 3 and 9 while retaining their migration potential to regenerating liver. Our findings implicated that mesenchymal stem cell administration during liver regeneration modulate the immune response through changing the expression of the TLRs in the remaining liver parts into which the cells are recruited or infused. This alteration may contribute to the regeneration process following partial hepatectomy.Karaciğer hücresi nakli, karaciğer yetmezliğinde ortotopik hücre nakline güçlü bir alternatiftir. Son yıllarda, kök hücrelerin doğalarının, kinetiklerinin ve yenilenen karaciğer bölgesinde etkili bir şekilde toplanmalarının sağlanmasının anlaşılması için hatırı sayılır gayretler sarf edilmektedir. Mesenkimal kök hücreler karaciğer yenilenme sürecini modüle eden ümit verici hücre kaynaklarından bir tanesidir. Bu çalışma, mezenkimal kök hücrelerin sıçanlarda toll benzeri reseptör (TLR) ifadesini değiştirmek suretiyle karaciğer immün yanıtını nasıl etkileyebildiklerini ve karaciğer yenilenmesi esnasında yenilenme potansiyelini arttırabildiklerini belirlemek için gerçekleştirilmiştir. Normal ve karaciğerleri kısmen çıkarılmış sıçanlar, sıçan kemik iliğinden elde edilip çoğaltılan mesenkimal kök hücreler ile muamele edilmişlerdir. Mesenkimal kök hücrelerin toplanması Eş Zamanlı Polimeraz Zincir Reaksiyonu (RT-PCR), Floresan Aktivite Hücre Ayırma (FACS), ve Immunfloresan Boyama (IFS) ile doğrulanmıştır. Sham ve karaciğeri kısmen alınmış sıçan grupları arasındaki farklılığın istatistiki analizinde Student's t-testi kullanılmıştır. Elde edilen sonuçlar mezenkimal kök hücrelerinde çeşitli TLR’lerin ifade edildiklerini ve bu hücrelerin yenilenme esnasında toplanmalarının meydana gelen hasarın zamanlamasına bağlı olduğunu göstermiştir. Normal sıçanların kemik iliğinden izole edilen mezenkimal kök hücreler hasarlı karaciğerde enjeksiyon sonrası 3. günde görülmüşlerdir. Hasarsız hayvanların karaciğer kesitlerinde işaretli bir mezenkimal kök hücre görülmemiştir. Mezenkimal kök hücre uygulaması TLR2, 3 ve 9'un ifadesinin anlamlı bir şekilde değiştirirken yenilenen karaciğere göç etme yeteneklerini devam ettirmişlerdir. Sonuçlar, karaciğer yenilenmesi esnasında mezenkimal kök hücre uygulamasının, hücrelerin uygulandığı hasarsız karaciğer parçalarında TLR’lerin ifadelerini değiştirme yoluyla immün yanıtı modüle ettiğini ortaya koymaktadır. TLR ifadesindeki bu değişim kısmı hepatoktemi sonrası yenilenme sürecine katkı sağlayabilir niteliktedir

Evaluation of dental anxiety in patients undergoing second-stage surgery with er, cr: YSGG laser treatment: Randomized clinical trial

Oral surgical procedures cause high-pain expectation and consequent anxiety in patients. The aim of this study is to compare the effects of Er, Cr: YSGG laser and scalpel method on dental anxiety level during second-stage implant surgery. 96 patients with 304 osseointegrated implants were divided into two groups. Implants embedded under the oral mucosa were exposed with scalpel or laser surgery. Before the operation the patients were asked to fill the STAI and DAS while resting in the waiting room. In addition, postoperative daily analgesic use, VAS scores perioperativly and on the postoperative 1st, 2nd and 3rd days and demographic information such as age and gender were also recorded. There was no statistically significant relationship between surgical method and anxiety levels (p&gt;0.05. Also, the differences between the scalpel and laser groups in terms of total DAS and STAI scores were statistically insignificant (p&gt;0.05). But statistically significant difference was found between surgical method and the analgesic consumption (p&lt;0.05). A higher rate of analgesic consumption was observed in the scalpel group. The use of Er,Cr;YSGG laser could reduce pain during minor oral surgical procedures but had no significant effect on dental anxiety. Different modalities that could provide additional benefits in overcoming this situation should be investigated. © 2020, Yuzuncu Yil Universitesi Tip Fakultesi. All rights reserved

Comparison of The Anxiety Levels Between The Family Members of The Patients Presenting to The Pediatric Trauma Unit and Pediatric Emergency Units

INTRODUCTION: It is not the right behaviour to accept every anxiety pathologically. On the contrary, the sense of anxiety is an indicator of the response of individuals to internal or external changes. More importantly, anxiety is a beneficial affective state for individuals who contribute to the development of self and bodily adaptability to the new environment in which they live. MATERIAL AND METHODS: This is a prospective study. The study was conducted on the parents of the patients who applied to the paediatric emergency department and paediatric trauma units of the emergency department at Atatürk University Faculty of Medicine. Beck Anxiety Scale was administered to one of the relatives who brought the patient to the hospital. Beck anxiety test was filled in by using face-to-face interview method. Pre-defined study forms for patients included in the study were completed. RESULTS: The study was completed with 68 family members in both groups. The values of the patients who were admitted to the paediatric emergency and adult emergency departments on the Beck Anxiety Scale were equal. CONCLUSIONS: family members of paediatric patients admitted to hospital were compared; The family members of the paediatric trauma unit and the family members of the paediatric emergency department have the same level of anxiety