Development of Highly Luminescent Water-Insoluble Carbon Dots by Using Calix[4]pyrrole as the Carbon Precursor and Their Potential Application in Organic Solar Cells.

Carbon dots (CDs) are carbon-based fluorescent nanomaterials that are of interest in different research areas due to their low cost production and low toxicity. Considering their unique photophysical properties, hydrophobic/amphiphilic CDs are powerful alternatives to metal-based quantum dots in LED and photovoltaic cell designs. On the other hand, CDs possess a considerably high amount of surface defects that give rise to two significant drawbacks: (1) causing decrease in quantum yield (QY), a crucial drawback that limits their utilization in LEDs, and (2) affecting the efficiency of charge transfer, a significant factor that limits the use of CDs in photovoltaic cells. In this study, we synthesized highly luminescent, water-insoluble, slightly amphiphilic CDs by using a macrocyclic compound, calix[4]pyrrole, for the first time in the literature. Calix[4]pyrrole-derived CDs (CP-DOTs) were highly luminescent with a QY of over 60% and size of around 4-10 nm with graphitic structure. The high quantum yield of CP-DOTs indicated that they had less amount of surface defects. Furthermore, CP-DOTs were used as an additive in the active layer of organic solar cells (OSC). The photovoltaic parameters of OSCs improved upon addition of CDs. Our results indicated that calix[4]pyrrole is an excellent carbon precursor to synthesize highly luminescent and water-insoluble carbon dots, and CDs derived from calix[4]pyrrole are excellent candidates to improve optoelectronic devices.

The hydrothermal synthesis of blue-emitting boron-doped CQDs and its application for improving the photovoltaic parameters of organic solar cell.

In this work, boron-doped CQDs (B-CQDs) were synthesized by using boric acid, urea, and citric acid via hydrothermal method to use as a novel additive material for poly(3-hexylthiophene-2,5-diyl) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) based organic solar cells. The OSCs with an inverted device structure were fabricated on titanium dioxide (TiO2) thin film. It was showed the crystallinity, morphological and optical properties of P3HT:PCBM films improved after B-CQDs additive. The best performance was obtained to be a 39.65% of FF, a 546 mV of Voc, an 8.606 mA cm-2 of Jsc after 3 vol.% B-CQDs addition in P3HT:PCBM blend. The power conversion efficiency (PCE) enhanced from 1.72% (non-doped device) to 2.33% (3% of B-CQDs) (a ~ 35% increase). The obtained results provided that B-CQDs are promising materials to improve the performance of solar cell applications. The novelty of this work is to improve the performance of OSCs using cost-effective and eco-friendly Boron CQDs as an additive. Besides, to achieve a good PCE of OSCs, it is necessary for utilized clean and green energy.

One of the Rare Causes of Acute Abdomen Leading to Subileus: Jejunal Diverticulitis.

BACKGROUND: Jejunal diverticulitis is one of the rare causes of acute abdomen generally seen in the elderly. Jejunal diverticulosis was defined as the herniation of the mucosa and the submucosa from the inside of the muscular layer of the bowel wall on the mesenteric side of the intestine. CASE REPORT: We presented the intraoperative and pathological findings of a 69-year-old male patient who had presented with complaints about abdominal pain, nausea, and vomiting and been operated upon due to subileus and peritonitis induced by large-sized jejunal diverticulitis, along with his computed tomography (CT) findings. CONCLUSION: Jejunal diverticulitis is uncommon and may be a disease which might be difficult to diagnose when it develops on the basis of the large-sized diverticula resembling intestinal ansae. To the best of our knowledge, the computed tomography and intraoperative findings of a case in which partial resection is applied to the jejunum due to subileus have not been previously presented in the literature.

The diagnostic importance of evaluation of solid breast masses by sonoelastography.

OBJECTIVE: The aim of this study was to determine whether the use of a scoring method by sonoelastography in solid breast masses is helpful in differentiating benign and malignant lesions. MATERIAL AND METHODS: One hundred and eighty solid breast masses in 155 patients (147 benign, 33 malignant) were prospectively evaluated in a two-year period. For each lesion, B-mode sonography and sonoelastography images were obtained. Elasticity scores of the lesions were determined with a 5-point scoring method by sonoelastography. The findings were compared with histopathology. The diagnostic performances of the sonoelastographic scoring and B-mode sonography methods were determined. RESULTS: The mean scores on sonoelastography were 2.61±0.62 for benign lesions and 3.73±0.69 for malignant lesions. When a cutoff point between scores 3 and 4 was used, accuracy, sensitivity, specificity, positive and negative predictive values for B-mode sonography were found as 81%, 89%, 79%, 46% and 97%, respectively; these were 87%, 73%, 91%, 69% and 92% for the sonoelastographic scoring method. CONCLUSION: After B-mode sonography analysis, the evaluation with the 5-point scoring method by sonoelastography might be a complementary method that increases specificity when differentiating between benign and malignant solid breast masses.

Qualitative and semiquantitative evaluations of solid breast lesions by sonoelastography.

OBJECTIVES: Our purpose was to determine whether the combination of a qualitative elasticity scoring method and a semiquantitative strain index method by sonoelastography is useful for differentiating between benign and malignant breast masses. METHODS: Seventy-eight lesions in 71 consecutive patients with solid breast masses (62 benign and 16 malignant) were prospectively included in this study. For each lesion, B-mode sonographic and sonoelastographic images were obtained. After elasticity scores had been determined with a 5-point scoring method, strain indices of the lesions were calculated using a same-level and normal-appearing breast region as an internal reference by means of strain ratio measurement. The findings were compared with histopathologic findings. With the use of receiver operating characteristic curves, the diagnostic performances of the elasticity scoring and strain index methods were determined. RESULTS: The mean scores ± SD on sonoelastography were 2.69 ± 0.59 for benign lesions and 3.75 ± 0.68 for malignant lesions. The mean stiffness index values were 2.03 ± 2.67 for benign lesions and 5.97 ± 4.45 for malignant lesions. The areas under the curves were 0.864 for 5-point scoring and 0.840 for the strain index. Sensitivity and specificity were 80% and 95%, respectively, for 5-point scoring, 87.5% and 72.6% for B-mode sonography, and 80% and 93% for the strain index when a cutoff point of 3.52 was used. A semiquantitative evaluation using the strain index did not contribute to the qualitative scoring evaluation. CONCLUSIONS: After 5-point scoring with sonoelastography, additional measurement with the strain index is not mandatory for differentiating between benign and malignant breast masses.

Symptomatic intestinal lipomas requiring surgical interventions secondary to ileal intussusception and colonic obstruction: report of two cases.

Lipomas are rare but well-recognized tumours of the small and large intestines. They usually arise from the submucosa and may occasionally protrude into the lumen, thus causing abdominal pain resulting from obstruction or intussusception or they may become evident through haemorrhage. Intestinal lipomas should be removed either endoscopically or surgically because they can cause severe symptoms and usually a tissue diagnosis is indicated in intestinal tumours to exclude a malignancy. We describe two cases of symptomatic intestinal lipoma and review some aspects of diagnosis and treatment.

Is rectal washout necessary in anterior resection for rectal cancer? A prospective clinical study.

BACKGROUND: Implantation of exfoliated malignant cells has been suggested as a possible mechanism of tumor recurrence in colorectal anastomoses that might be prevented by cytocidal washout. The aim of our study was to assess whether malignant cells are likely to be collected by a circular stapler introduced transanally to perform an anastomosis and to observe local recurrences during follow-up, with special attention to the washout status of patients. METHODS: Between May 1999 and March 2004, 96 patients with carcinoma of the rectum and distal sigmoid colon undergoing anterior resection under the care of three surgeons (only one of whom routinely performed rectal washout) were prospectively studied. While 38 patients had rectal washout with 5% povidone-iodine before anastomosis, 58 patients did not. A circular stapler was used for anastomosis, and the stapler was immediately rinsed in 100 ml of saline. The fluid was then classified as "acellular," "malignant cells identified," or "benign cells identified" by pathologists. RESULTS: Malignant cells were collected from the circular stapler after use in 3 patients (8%) on whom rectal washout was performed and in 2 (3%) patients who did not have rectal washout performed (P=0.631). Three patients (8%) in the washout group developed local recurrence, and 2 patients (3.4%) in the no-washout group had local recurrence (one was anastomotic recurrence) (P=0.338). The median follow-up time was 23 (range: 9-70) months. CONCLUSIONS: There were no differences in terms of the number of patients who had malignant cells collected from the circular stapler and local recurrence rates between the two groups. Although this is not a randomized study and size and mean follow-up time of the study were not sufficient, our results did not offer rational arguments in support of intraoperative rectal washout when a circular stapler is used after low anterior resection for carcinoma. Because of the limitations of our study, however, we are unable to arrive at a definite conclusion regarding rectal washout. There is a need for a randomized, controlled, large-scale, multicenter trial to establish the clinical relevance of intraoperative rectal washout.