Role Of Morphological Features Research Articles

Role of morphological features and oxygen vacancies on electrocatalytic oxygen evolution reaction (OER) activity and pseudocapacitance performance of BiVO4 structures

In the present study, bismuth vanadate nanostructures have been synthesized by hydrothermal route. The final calcination has been carried out in an open atmosphere and also inside the closed system (autoclave). The role of morphology, defects, and oxygen vacancies generated during the synthesis in the open air and in limited supply of oxygen on electrochemical oxygen evolution reaction and capacitor performance has been studied. The samples synthesized in open air exhibit fine size and uniform distribution of particles. However, the samples synthesized in autoclave reveal larger size particles, a greater number of defect states, and oxygen vacancies. The sample synthesized in open air elucidates a lower water oxidation overpotential of 170 mV to retrieve current density of 10 mA cm−2. The results predict that morphological features play a vital role in electrocatalytic activity compared to defect states and vacancies. To avoid the prevailing confusion regarding the electrode materials for electrochemical capacitors and batteries, the actual pseudocapacitor behavior of the synthesized samples has been studied by cyclic voltammetry (CV) and galvanic charge–discharge characteristics performed at different scan rates and applied currents, respectively. The synthesized samples exhibit higher capacitance retention (>95%) during continuous CV cycling.

Prediction of mismatch repair deficient biliary tract cancer: Role of morphological features and host immune response detected by routine hematoxylin-eosin staining.

The objective of this study was to determine the frequency and predictors of biliary tract cancer (BTC) with deficient DNA mismatch repair (dMMR) in Japan. Immunostaining and microsatellite instability analysis were performed for mismatch repair-related proteins in tissue specimens from 662 patients who underwent surgery for BTC between 2001 and 2017 to identify dMMR-BTC. We compared dMMR-BTC and proficient MMR (pMMR)-BTC based on patient demographics, pathological features, and host immune responses characterized by the percentage of stromal tumor infiltrating lymphocytes (sTIL percentage) and tertiary lymphoid structures (TLS). The incidence of dMMR-BTC was 2.3%. Significant predictors of dMMR-BTC were its primary lesion being intrahepatic cholangiocarcinoma (odds ratio [OR] 6.34, P=.004), presence of signet ring cell component (OR 35.62, P<.001), sTIL percentage ≥40% (OR 3.43, P=.038), and presence of TLS (OR 22.22, P<.001). The sensitivity, specificity, and negative likelihood ratio for any one or more of these four variables to be positive were 93.3%, 57.8%, and 0.12, respectively. Evaluation of histopathological findings and host immune response based on conventional histochemical staining is useful for efficient and inexpensive diagnostic screening of dMMR-BTC patients.

Surgical management of pleomorphic adenoma of parotid gland in elderly patients: Role of morphological features

The neoplasms of the salivary glands account for 2% of head and neck tumors and the most common form is the Pleomorphic adenoma (PA). Parotid gland is affected from 80% to 90% of cases. In elderly these tumors occur mostly in females. These benign tumors are composed of epithelial and myoepithelial cells that are arranged with various morphological patterns and subtypes. The classification of these tumors is also based on the amount and nature of the stroma. In literature there is an almost complete consensus that, in the major salivary glands, PAs are enclosed by a layer of fibrous tissue often called “capsule” but there is disagreement about the form, extension and thickness of this layer. The treatment is surgical and there are two main different surgical approaches: an enucleation (local dissection) or so-called subtotal superficial parotidectomy and lateral or superficial total parotidectomy. Histopathological characteristics of PAs especially of capsular alterations such as thin capsule areas, capsule-free regions, capsule penetration, satellite nodules and pseudopodia in the different subtypes are important for the choice of surgical treatment and the first explanation for tumor recurrence. In our study we describe a morphological features of 84 cases of pleomorphic adenoma of parotid gland from elderly patients treated by a surgical “enucleation like” method called nucleoresection.

Effect of pinealectomy on the morphology of the chick cervical spinal cord: A stereological and histopathological study

Melatonin has some effects upon morphological features of various structures in small animals and human being. In this study, the changes induced by pinealectomy procedure on morphological features of developing cervical spinal cord and their neurons in the gray matter (GM) and white matter (WM) of cervical spinal cord in the chicken were investigated. A total of 15 Hybro Broiler newly hatched chicks were randomly divided into three equal groups: unoperated control group ( n = 5), sham-operated group ( n = 5) and pinealectomy group ( n = 5). Pinealectomy procedure and sham operation were done in 3-day-old chicks and all animals were sacrificed at the 8th week and the 6th cervical (C6) spinal cord segment was dissected out for histopathological evaluation and subsequent stereological analysis. The volume of spinal cord segment did not show a significant difference between unoperated and sham-operated controls, but the pinealectomy group has a declined volume value compared with those of the control and sham operated groups ( P < 0.01). By contrast, there was no statistically significant difference between unoperated and sham-operated controls and the pinealectomy group with regard to volume fraction of the GM and WM of the cervical spinal cord. Finally, it was observed that pinealectomy procedure significantly reduces neuron number in the GM and the volume of WM of the C6 segment of cervical spinal cord in the chicken ( P < 0.001). The present study is the first study at all to evaluate the effects of pinealectomy on quantitative feature of the spinal cord in the chicken. Based on our findings, we suggest that pineal gland/melatonin might play an important role in morphological features of the developing spinal cord in the chicken.

Neonatal pinealectomy induces Purkinje cell loss in the cerebellum of the chick: A stereological study

Melatonin plays an important role in certain physiological functions and morphological features of various structures. In the current study, the effects of pinealectomy on Purkinje cell number and morphological features of developing cerebellum in the chick were investigated using stereological methods. Fifteen Hybro Broiler newly hatched chicks were divided into three groups: a pinealectomized group ( n = 5), sham-operated group ( n = 5) and a non-pinealectomized control group ( n = 5). Surgical pinealectomy was performed in 3-day-old chicks. In the 8th week, all animals were sacrificed for histopathological evaluation and subsequent stereological analysis. Each layer volume of molecular (+Purkinje cell), granular and white matter in the cerebellum was estimated in all animals. It was found that there was no significant difference for the volume of whole cerebellum and also molecular (+Purkinje cell) layer in these groups ( P > 0.05). Nevertheless, the values of granular layer and white matter of sham-operated group were significantly different from those of control and pinealectomized animals ( P < 0.01). It was also observed that pinealectomy significantly reduces the Purkinje cell number in cerebellar cortex ( P < 0.01). The present study is the first stereological study to demonstrate the histomorphological effects of pinealectomy on the cerebellum in the chick. Our results suggest that pineal gland/melatonin might play an important role in morphological features of the developing cerebellum in the chick.