Misconceptions about diffusion and osmosis concepts held by secondary education 9th level students

Difüzyon, osmoz ve çözeltilerde partikül hareketleri fen derslerinde önemli bir konuma sahip olup, bu kavramların öğrenciler tarafından öğrenilmesi ve anlaşılır olması biyoloji eğitiminde büyük öneme sahiptir. Bu nedenle difüzyon ve ozmos kavramlarının öğrenilmesinde öğrencilerde bir çok kavram yanılgısına sıkça rastlanır. Difüzyon ve ozmosun lise öğreniminde önemli kavramlar olması nedeni ile bu kavramlarla ilgili yanılgıların araştırılması bu çalışmada amaçlanmıştır. Bilimsel olarak bu kavramların öğrencilere kavratılması için neler yapılması gerektiği araştırılmıştır. Bu çalışmada açık uçlu sorulardan oluşan bir anket öğrencilere öncelikli olarak uygulamış olup, öğrencilerin difüzyon, ozmos, çözeltide partiküllerin rast gele hareketi ve yarı geçirgen hücre zarından madde geçişi ile ilgili cevaplarının doğruluk derecesi Hasan ve ark. (1999) tarafından geliştirilen bir Cevap Doğruluk İndeksi (CDİ) ile değerlendirilmiştir. Buna göre öğrencilerin CDİ değerleri <3' ten küçük bulunmuş olup, bu değer öğrencilerin cevaplarının bilinçli ve doğru olmayıp çoğunlukla tahmine dayalı olduğunu göstermiştir. Öğrencilerin kavramlarla ilgili temel bilgilerinin oldukça yetersiz ve çok sayıda kavram yanılgısı içerdiğini göstermiştir. Sonuç olarak öğrencilerin yetersiz bilgi seviyelerinin yapılandırıcı bir yaklaşımla öğrencilerin deneysel süreçte yer alması, deneye katılmaları, sonuçları kaydedip analiz etme sürecine katılmaları gerektiği önerilmiştir. Elde edilen sonuçların sınıf ortamında tartışılması kavramlarla ilgili kavram yanılgılarının en aza indirilmesine olanak sağlayabilir. Öğretmenin kavramsal bağlantıların kurulmasına yardımcı olması, öğrenci tartışmalarını ve kavramsal ilişkileri yönlendirmesi difüzyon, ozmosla ilgili temel kavramların öğrenilmesine katkıda bulunabilir.The concepts of diffusion, osmosis and random nature of matter are very common in science instruction, and understanding these concepts is an important precursor to instruction in biology education. It appears that misconceptions may play a larger role students learn diffusion and osmosis concepts. Because of its importance of diffusion and osmosis, it may be beneficial to investigate misconceptions of high school students. The purpose of this study was to investigate students' understanding about scientifically acceptable content knowledge by exploring the relationship between knowledge of diffusion and osmosis and a student's confidence in their content knowledge following instruction. A validated two-tier diagnostic test designed to assess understanding of diffusion and osmosis concepts. The test was open ended in the first step that students freely expressed their basic knowledge about diffusion, osmosis, random nature of matters and the function of semi-permeable cell membranes. In the second step the answers of students assessed and scored according to previously developed a measuring scale Hasan et al. (1999). The findings of study have been shown that most of students were have not good enough basic knowledge about diffusion, osmosis, random nature of matters and the function of semi-permeable cell membranes. Mostly Correct answer index (CAI) was lower than 3 that show randomly replying the questions and mostly guessed. Also many misconceptions detected and discussed in this study. As a result, It is possible suggest that students should actively engaged in constructing knowledge. During each phase of the learning, students should actively manipulating materials, recording data, or analyzing results. Students should encourage discussing findings in groups and with the class. The teacher acts as a facilitator via making connections between concepts. Students may debate and argue relationships between concepts and their content this may provide paying their attention experiences with the concepts

Inflammatory myofibroblastic tumor of the small-bowel mesentery: A case report of nonspecific clinical presentation and a review of the literature

INTRODUCTION: Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm of various anatomical sites, which is histopathologically characterized by spindle-shaped cells with myofibroblastic proliferation and inflammatory infiltration. PRESENTATION OF CASE: In this case report, a 37-year-old man presented with nonspecific systemic symptoms, including abdominal pain and weakness, which was diagnosed by multislice computed tomography and ultrasonography. An 8 cm × 5 cm × 5 cm nodular gray-white firm noninfiltrative mass, which was well localized in the mesentery tissues of small bowel, was observed and the patient underwent surgical resection. DISCUSSION: A review of the literature on IMT of the small-bowel mesentery yielded a small number of previously described cases. This tumor most frequently involves the lungs and arises most commonly in extrapulmonary locations such as the mesentery and omentum. The etiopathogenesis and the clinical course of the disease are unclear. The histological and clinical differential diagnosis of IMT also includes reactive processes and mesenchymal tumors of the gastrointestinal tract. Follow-up after surgical removal documented local recurrence and metastasis. CONCLUSION: The preferred primary treatment is complete surgical excision, and patients require close clinicoradiological follow-up. In general, cases treated with complete surgical resection have a good prognosis

Clinicopathological and molecular features of sporadic colorectal cancers with DNA mismatch repair deficiency: A single center experience

DNA mismatch repair (MMR) proteins may play an important role in colorectal carcinogenesis. In our study, the clinicopathological features of defective MMR in sporadic colorectal adenocarcinomas (CRCs) cases were examined. This is a retrospective study, 457 consecutive cases of colorectal carcinoma with immunohistochemical (IHC) studies for DNA MMR were included.The immunohistochemically (IHC) MMR results of 457 cases were; nuclear expression was intact (proficient, pMMR) in 401 (87.7%) cases and loss of nuclear expression (deficient, dMMR) was found in 56 cases (12.3%). High probability of Lynch syndrome ratio was 2.4% (11/457) in all cases. The loss of PMS2 was predominantly detected in dMMRcases (78.6%). Seventy eight percent of dMMR tumors were located in the proximal colon. In dMMR tumors, prominent peritumoral lymphoid aggregates (LAs) (85.7%) and tumor-infiltrating lymphocytes (TILs) (78.6%) were observed. Among 56 colorectal cancers, we observed expanding /pushing growth pattern in 41 tumors (73.2%), and infiltrative growth pattern in 15 cancers (16.8%). Medullary, mucinous and signet ring cell carcinomas were observed in approximately half of the cases, but there was no statistically significant relationship. Eighty nine percent of dMMR cases had advanced pathologic tumor stage (pT3 or pT4), and this rate was 82.5% in pMMR cases. The average number of positive lymph nodes in cases with dMMR was higher than in pMMR. KRAS mutations were detected in 7.2% (4/13) patients and 14.3% (8/13) patients with MLH1 promoter methylation was observed. Seventy percent of patients with dMMR were alive (n=44) and the mean age of the patients who died was higher. A statistically significant relationship was found between the patients who died and the mean age of surviving patients (p = 0.036). We conclude that the dMMR patients constitutes have a number of distinctive clinicopathological features subtype of sporadic CRC. The overall frequency of defective MMR in colorectal carcinoma cases was found to be Turkish population similar to western studies. dMMR in CRCs were more likely to be of advanced pathologic tumor stage to have a mucinous tumor component and positive LN to show PMS2 loss and to harbour higher numbers of both peritumoral LAs and TILs. They were also more likely to be proximal colon and to occur in male. [Med-Science 2020; 9(4.000): 1014-22

A rare case of giant gastrointestinal stromal tumor of the stomach involving the serosal surface

Introduction: Although rare, gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors affecting the gastrointestinal tract. Presentation of case: Here we report the case of a 43-year-old man complaining of abdominal pain along with a painless and palpable mass, which was confirmed on magnetic resonance and multislice computed tomography. Laparotomy revealed a nodular grayish-white firm noninfiltrative mass (39 × 27 × 14 cm, 6109 g) that was well localized within the extramuscular and peritoneal surface of the anterior wall of the stomach; complete tumor resection was performed. Histopathological examination revealed features typical of GIST, including increased cellularity, increased mitotic activity, and spindle shaped cells as well as positive immunoreactivity for KIT, CD34, and vimentin. Discussion: A review of literature revealed that GISTs of the size and weight similar to the present case has been rarely reported. GIST most frequently involves the stomach. Although the etiopathogenesis of this disease remains unclear, few well-documented familial cases have been associated with GIST syndromes. Conclusion: The primary treatment preferred is complete surgical excision of the tumor

Do histopathologic findings improve by increasing the sample size in cholecystectomies?

BACKGROUND: Gallbladder diseases present with cholelithiasis in a wide spectrum of adenomas and cancers. Two or three specimens are sampled in cholecystectomies in routine pathology practice. The aim of this study was to investigate the increase in frequency of histologic alterations in cholecystectomies, particularly precancerous lesions, by increasing the sample size to understand the carcinoma pathway. METHODS: Cholecystectomies of 432 patients with pathology records and materials from two medical centers were collected, and two groups were created. Initial data with two or three samples were allocated to Group 1 and the new six samples with the initial ones were allocated to Group 2. Hematoxylin and eosin (H&E) sections were examined for histopathologic alterations, and periodic acid–Schiff (PAS) Alcian blue (pH 2.5) and high iron diamine (pH 2.5) stains were used to signify the mucin profile in case of metaplasias. For the comparison of findings, non-parametric tests, McNemar’s tests, chi-squared tests and Fisher’s exact test were performed. RESULTS: Of the 432 patients, 308 (71.3%) patients were female and 124 (28.7%) patients were male. The mean age of patients was 47.9 ± 14.6 years. Cholesterolosis was observed in 95 (22%) patients in Group 1 and 108 (25%) patients in Group 2. Gallstones were detected in 255 (59%) of the cholecystectomies. There was a significant difference between Group 1 and Group 2 by increasing the sample size when we compared cholesterolosis, metaplasia and polyps (P <0.05). Cholecystitis and dysplasia rates were the same in both of the groups. There was no cancer determined. CONCLUSION: Increasing the sample size in cholecystectomies increased the diagnosis of some histologic alterations, but further studies with a larger number of samples over a longer period time might increase the ability to determine precancerous lesions and concomitants