Holocene palaeoceanographic evolution of the Iskenderun bay, South-Eastern Turkey, as a response to river mouth diversions and human impact

A quantitative study of benthic foraminifera, sediment texture and composition from two cores was performed to unravel the environmental evolution of the Iskenderun Bay (eastern Turkey) in the Holocene. Core 29 (NE Iskenderun Bay) consists of clay and silt from the top of the core down to 35 cm with dominant bioclasts (coral Cladocora caespitosa) from 35 cm down to the bottom of the core. Core 92, located near an ancient Ceyhan River mouth (Yumurtalik), consists of sandy and silty sediment passing to homogeneous clay and silt at about 48 cm from the top. Several grab samples show very coarse biogenic detritus covered by a centimetric veneer of sandy silt and clay. Radiocarbon dating of corals, molluscs and algae from core 29 and five selected grab samples, the sediment and foraminiferal study indicate that at least three pulses of muddy sedimentation occurred in the bay. (1) An older pulse (about 3700 yrs BP) related to the large-scale forest clearing (Beysheir Occupation Phase). (2) Another pulse coincides with a major delta progradation of the Ceyhan River at about 2140 years BP. (3) A younger pulse follows the diversion of the Ceyhan River mouth toward Yumurtalik, from the Middle Age to 1935.Species interpreted as tolerant of low salinity indicate that the influence of the Ceyhan was minor when the river drained directly into the Mediterranean Sea (approximately 2000 years BP) and progressively increased when the river diverted towards Yumurtalik

Terahertz Time-Domain Study of Silver Nanoparticles Synthesized by Laser Ablation in Organic Liquid

We report the investigation of laser-synthesized Ag nanoparticles (Ag-NPs) in an organic liquid environment by using terahertz time-domain spectroscopy (THz-TDS) technique. Colloidal Ag-NPs with an average diameter of 10 nm in two-propanol solution through nanosecond pulsed laser ablation were synthesized. THz-TDS measurements were performed on different volumetric concentration of Ag-NPs suspensions placed in 2-mm path length quartz cuvette. Due to the dispersive and highly absorptive nature of the nano liquids, an approach based on extracting the optical properties through the changes in amplitude and phase solely around the main peak of THz waveform is developed. This approach allowed for an accurate estimation of the complex refractive index of the Metallic-NPs suspension for the different prepared volumetric concentrations. In addition, using Maxwell-Garnett theory, the NP concentration is also extracted. This method shows that the time-domain nature of the THz pulse measurement technique is extremely useful in instances where slight variations in highly dispersive samples need to be investigated. � 2016 IEEE

Regularized reconstruction in quantitative SPECT using CT side information from hybrid imaging

A penalized-likelihood (PL) SPECT reconstruction method using a modified regularizer that accounts for anatomical boundary side information was implemented to achieve accurate estimates of both the total target activity and the activity distribution within targets. In both simulations and experimental I-131 phantom studies, reconstructions from (1) penalized likelihood employing CT-side information-based regularization (PL-CT), (2) penalized likelihood with edge preserving regularization (no CT) and (3) penalized likelihood with conventional spatially invariant quadratic regularization (no CT) were compared with (4) ordered subset expectation maximization (OSEM), which is the iterative algorithm conventionally used in clinics for quantitative SPECT. Evaluations included phantom studies with perfect and imperfect side information and studies with uniform and non-uniform activity distributions in the target. For targets with uniform activity, the PL-CT images and profiles were closest to the 'truth', avoided the edge offshoots evident with OSEM and minimized the blurring across boundaries evident with regularization without CT information. Apart from visual comparison, reconstruction accuracy was evaluated using the bias and standard deviation (STD) of the total target activity estimate and the root mean square error (RMSE) of the activity distribution within the target. PL-CT reconstruction reduced both bias and RMSE compared with regularization without side information. When compared with unregularized OSEM, PL-CT reduced RMSE and STD while bias was comparable. For targets with non-uniform activity, these improvements with PL-CT were observed only when the change in activity was matched by a change in the anatomical image and the corresponding inner boundary was also used to control the regularization. In summary, the present work demonstrates the potential of using CT side information to obtain improved estimates of the activity distribution in targets without sacrificing the accuracy of total target activity estimation. The method is best suited for data acquired on hybrid systems where SPECT-CT misregistration is minimized. To demonstrate clinical application, the PL reconstruction with CT-based regularization was applied to data from a patient who underwent SPECT/CT imaging for tumor dosimetry following I-131 radioimmunotherapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85409/1/pmb10_9_007.pd

Feasibility of sharpening limited-angle tomography by including an orthogonal set of projections

In single photon emission nuclear medicine, computed tomography systems that employ only a limited angular range of projection data suffer from blurring in the depth (or z) direction. With simulated data, we show that including a second set of projections taken in an orthogonal direction sharpens the image in the z direction. For heart applications, this sharpening improves the sizing of a simulated 2 cm diameter "hot" infarct by 39%. It also should improve the contrast of "cold" infarcts by eliminating blurring from other planes, but here we have found a complication, in that, with the present approximate algorithm, effects from the lack of symmetry in two-view tomography may overshadow benefits from contrast improvement. Further simulation study is called for.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24056/1/0000307.pd

Perspective of turkish medicine students on cancer, cancer treatments, palliative care, and oncologists (ares study): A study of the palliative care working committee of the turkish oncology group (TOG)

Cancer is one of the most common causes of death all over the World (Rahib et al. in Cancer Res 74(11):2913–2921, 2014; Silbermann et al. in Ann Oncol 23(Suppl 3):iii15–iii28, 2012). It is crucial to diagnose this disease early by effective screening methods and also it is very important to acknowledge the community on various aspects of this disease such as the treatment methods and palliative care. Not only the oncologists but every medical doctor should be educated well in dealing with cancer patients. Previous studies suggested various opinions on the level of oncology education in medical schools (Pavlidis et al. in Ann Oncol 16(5):840–841, 2005). In this study, the perspectives of medical students on cancer, its treatment, palliative care, and the oncologists were analyzed in relation to their educational status. A multicenter survey analysis was performed on a total of 4224 medical school students that accepted to enter this study in Turkey. After the questions about the demographical characteristics of the students, their perspectives on the definition, diagnosis, screening, and treatment methods of cancer and their way of understanding metastatic disease as well as palliative care were analyzed. The questionnaire includes questions with answers and a scoring system of Likert type 5 (absolutely disagree = 1, completely agree = 5). In the last part of the questionnaire, there were some words to detect what the words “cancer” and “oncologist” meant for the students. The participant students were analyzed in two study groups; “group 1” (n = 1.255) were phases I and II students that had never attended an oncology lesson, and “group 2” (n = 2.969) were phases III to VI students that had attended oncology lessons in the medical school. SPSS v17 was used for the database and statistical analyses. A value of p < 0.05 was noted as statistically significant. Group 1 defined cancer as a contagious disease (p = 0.00025), they believed that early diagnosis was never possible (p = 0.042), all people with a diagnosis of cancer would certainly die (p = 0.044), and chemotherapy was not successful in a metastatic disease (p = 0.003) as compared to group 2. The rate of the students that believed gastric cancer screening was a part of the national screening policy was significantly more in group 1 than in group 2 (p = 0.00014). Group 2 had a higher anxiety level for themselves or their family members to become a cancer patient. Most of the students in both groups defined medical oncologists as warriors (57% in group 1 and 40% in group 2; p = 0.097), and cancer was reminding them of “death” (54% in group 1 and 48% in group 2; p = 0.102). This study suggested that oncology education was useful for the students’ understanding of cancer and related issues; however, the level of oncology education should be improved in medical schools in Turkey. This would be helpful for medical doctors to cope with many aspects of cancer as a major health care problem in this country. © 2018, American Association for Cancer Education

Testing of local gamma-ray scatter fractions determined by spectral fitting

The spectral-fitting method of correction for gamma-ray Compton scattering within objects separates the unscattered and scattered components of locally measured energy spectra. Here, the authors employ a third-order polynomial for the scattering and an approximately constant fitting window. A scatter fraction, defined as total scattered over total unscattered counts within a 20% window, is calculated for each point in the Anger camera images. These scatter fractions are tested against those from Monte-Carlo simulation for 99mTc and against results from semiconductor detector measurements for 131I. A radioactive sphere at several locations within a non-radioactive cylinder and the inverse are imaged for the testing. For one case, reproducibility of the spectral-fitting scatter fraction as a function of the number of unscattered counts within the 20% acceptance window was also determined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48957/2/pb910203.pd

MTG16 regulates colonic epithelial differentiation, colitis, and tumorigenesis by repressing E protein transcription factors

Aberrant epithelial differentiation and regeneration contribute to colon pathologies, including inflammatory bowel disease (iBD) and colitis-associated cancer (CAC). Myeloid translocation gene 16 (MTG16, also known as CBFA2T3) is a transcriptional corepressor expressed in the colonic epithelium. MTG16 deficiency in mice exacerbates colitis and increases tumor burden in CAC, though the underlying mechanisms remain unclear. Here, we identified MTG16 as a central mediator of epithelial differentiation, promoting goblet and restraining enteroendocrine cell development in homeostasis and enabling regeneration following dextran sulfate sodium-induced (DSS-induced) colitis. Transcriptomic analyses implicated increased Ephrussi box-binding transcription factor (E protein) activity in MTG16-deficient colon crypts. Using a mouse model with a point mutation that attenuates MTG16:E protein interactions (Mtg16(P20ST)), we showed that MTG16 exerts control over colonic epithelial differentiation and regeneration by repressing E protein-mediated transcription. Mimicking murine colitis, MTG16 expression was increased in biopsies from patients with active IBD compared with unaffected controls. Finally, uncoupling MTG16:E protein interactions partially phenocopied the enhanced tumorigenicity of Mtg16(-/)(-) colon in the azoxymethane/DSS-induced model of CAC, indicating that MTG16 protects from tumorigenesis through additional mechanisms. Collectively, our results demonstrate that MTG16, via its repression of E protein targets. is a key regulator of cell fate decisions during colon homeostasis, colitis, and cancer.Peer reviewe

Management and prognostic factors of recurrent pleomorphic adenoma of the parotid gland: personal experience and review of the literature

The aim of this study was to investigate the management and prognostic determinants of recurrent pleomorphic adenoma (RPA). A retrospective analysis was performed to examine the clinical features, the prevalence of surgical complications, and new recurrences of RPA. Tumor recurrence rate was estimated by the Kaplan–Meier method, and the prognostic value of some of the variables was tested by univariate analysis using the log rank test. The study focused on 33 patients, 18 female (54.5%) and 15 male (45.5%), aged 12–71 years (median 41). A total or extended total parotidectomy was performed in 16 cases (48.5%), a superficial parotidectomy in 10 cases (30.3%), and a local excision in 7 cases (21.2%). In ten patients (30.3%), a branch or the trunk of the facial nerve was deliberately sacrificed. Major complications included one unexpected definitive paralysis of the marginal mandibular branch of the facial nerve and 14 cases of Frey syndrome. Follow-up varied from 2 to 25 years (median 10.5 years), and there were 11 new recurrences (33.3%) within a period varying from 1 to 16 years (median 6 years). The estimated tumor recurrence rates were 14.1 ± 6.6% at 5 years, 31.4 ± 9.4% at 10 years, 43.0 ± 10.8% at 15 years, and 57.2 ± 14.8% at 20 years. Presence of a multinodular lesion and the type of intervention performed were significantly associated with a higher probability of recurrence. RPAs are prone to new recurrences, especially when multinodular and treated with a local excision. Surgical treatment should include facial nerve resection in selected cases. Follow-up for the patient’s lifetime is warranted

Quantitative autoradiographic evaluation of the influence of protein dose on monoclonal antibody distribution in human ovarian adenocarcinoma xenografts

We studied the effect of monoclonal antibody protein dose on the uniformity of radioiodinated antibody distribution within tumor masses using quantitative autoradiography. Groups ( n = 11–13/group) of athymic nude mice with subcutaneous HTB77 human ovarian carcinoma xenografts were injected intraperitoneally with an 125 I-labeled anticarcinoma-associated antigen murine monoclonal antibody, 5G6.4, using a high or a low protein dose (500 µg or 5 µg). At 6 days post-injection the macroscopic and microscopic intratumoral biodistribution of radiolabeled antibody was determined. The degree of heterogeneity of the labeled antibody distribution within each tumor was quantified and expressed as the coefficient of variation (CV) of the activity levels in serial histological sections. Tumors from mice given the 500-µg protein doses had substantially lower CV values, 0.327±0.027, than did tumors from animals given 5-µg protein doses, 0.458±0.041, ( P = 0.0078), indicating that the higher protein dose resulted in more homogeneous distribution of radioactivity in tumors than did the lower dose. While the percentage of the injected dose reaching the tumor was comparable between groups, injecting the higher dose of protein resulted in significantly lower tumor to non-tumor uptake ratios than those obtained for the lower protein dose. These data indicate, in this system, that to achieve more uniform intratumoral antibody (and radiation for radioimmunotherapy) delivery, a relatively high protein dose must be administered. However, to obtain this increased uniformity, a substantial drop in tumor/background uptake ratios was seen. Quantitative autoradiographic evaluation of human tumor xenografts is a useful method to assess the intratumoral distribution of antibodies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46859/1/262_2005_Article_BF01789014.pd