Theoretical, structural, and electronic analyses of pyridin-based dyes for dye-sensitized solar cells applications.

CONTEXT: The new series of donor-π-acceptor dyes have been designed using pyridine derivatives as a donor group and thienothiophene as a π-spacer group, which were linked via 10 acceptor groups. The highest occupied molecular orbital energies range from - 6.177 to - 5.786 eV, whereas the lowest unoccupied molecular orbital energies range from - 2.181 to - 3.664 eV. A6 dye has smaller energy gap, lower hardness, higher electrophilicity index, and good photovoltaic performance than other sensitizers. The lowest dihedral angle is observed in A1, A2, A6, A7, and A8 which are appropriate for intramolecular charge transfer between the molecules. The A8 has higher light harvesting efficiency, which increases the photovoltaic efficiency of the designed dye. The A6, A7, and A8 dyes spend less time in the excited state, which means they emit photons more efficiently than other dyes. The interaction between donor to π-spacer (red line) parts of the dyes has the bonding interaction (positive), and π-spacer to acceptor (blue line) parts of the dyes have the bonding and antibonding (negative) behaviours. The dyes A5 and A9 have 305.79 and 357.71 times higher ß0 values than urea (0.781 × 10-30 esu) molecules. The spectral properties of the A6 dye strongly affect the structural modification. METHODS: The density functional theory (DFT) and time-dependent DFT (TD-DFT) approach B3LYP/6-311G (d,p) basic set were used to optimize the designed dyes. All the calculations are performed using Gauss view 6.0 and Gaussian 09 software. The density of state spectrum is plotted using Gauss sum 2.6.

Immunohistochemical expression and evaluation of cyclin D1 and minichromosome maintenance 2 in oral squamous cell carcinoma and verrucous carcinoma.

Background: The study of cell proliferation is important for assessing the tumor behavior, prognosis and patient survival of oral carcinomas. As literature search did not reveal sufficient studies of immunohistochemical expression of cyclin D1 and minichromosome maintenance 2 (MCM2) in oral squamous cell carcinoma (OSCC) and verrucous carcinoma (VC), the present study was undertaken. Materials and Methods: The study group included 20 cases of histopathologically diagnosed OSCC, 10 cases of VC and 10 cases of normal mucosa (NM). All samples were evaluated for the expression of cyclin D1 and MCM2 using standard Immunohistochemistry (IHC) procedure.The present study involved both qualitative and quantitative analyses. Qualitative analysis was done by evaluation of intensity and area of staining. Quantitative analysis was done by calculating the percentage of positively stained cells and assessing the labeling index (LI). Data obtained were subjected to statistical analysis using SPSS statistical package (version 23.0). Results: On evaluating and comparing the intensity of staining and area of staining of cyclin D1 and MCM2 between the study groups, statistically significant values (P < 0.05) were obtained using Kruskal-Wallis ANOVA. Comparison of LI of cyclin D1 and MCM2 in NM, OSCC and VC statistically significant results (P < 0.05) was obtained using Mann-Whitney U-test. Mean LI of MCM2 was found to be significantly higher than mean LI of cyclin D1 in all the study groups. Conclusion: From the present study, we conclude that MCM2 has the potential to serve as a novel cell proliferation biomarker in OSCC and VC when compared to cyclin D1.

Stature Estimation of an Individual Using Nasal, Facial, and Palatal Height among Tamil Nadu Population.

BACKGROUND: Stature estimation in human identification has a significant forensic importance. The stature correlates positively with bones or human body parts. Measurements of various body parts such as the arm, leg, feet, and finger can be used to estimate stature. This study is done to correlate the stature of person with facial, nasal, and palatal height among Tamil Nadu population. AIM AND OBJECTIVE: The aim and objective was to determine an individual's stature using facial, nasal, and palatal height and to find out the most reliable parameter to determine the stature of the person. MATERIALS AND METHODS: Anthropometer, Vernier caliper, and palatometer were used for the analysis. The initial pilot study included 20 individuals. The representative study included 100 individuals of age 21-25 years. (Group 1 - males, Group 2 - females). Values of the three parameters (nasal, facial, and palatal) are calculated and related to that of the person's stature. RESULTS: The quantitative data collected from the subjects are studied using (Pearson correlation) statistical analysis. The quantitative data availed from nasal height were found to be more reliable compared to the other two data in stature prediction. Correlation between stature and nasal height shows a significant positive correlation among the female group (2) with (P- value = 0.57). CONCLUSION: This study may play a significant role in case of human identification immediately after mass disasters and certain criminal investigations. Further studies with larger samples may produce more reliable values.

Immunohistochemical detection of 8-hydroxydeoxyguanosine: A biomarker of oxidative DNA damage in oral submucous fibrosis.

BACKGROUND: Oral submucous fibrosis (OSMF) is one of the common potentially malignant disorders prevailing in India. The primary etiological factors include tobacco and arecanut, which contain numerous reactive oxygen species (ROS). ROS attack guanine bases in DNA and form 8-hydroxydeoxyguanosine (8-OHdG), which can be detected in patients who have diseases associated with oxidative stress. The oxidative DNA damage produced by oxidative stress may induce malignant transformation. AIM: The aim of the present study is to detect the expression of 8-OHdG in OSMF patients and compare the expression within different grades of OSMF and also normal buccal mucosa. MATERIALS AND METHODS: A total of 30 samples were examined for the immunohistochemical expression of 8-OHdG. The control group included 10 formalin-fixed paraffin-embedded tissue blocks of the normal buccal mucosa. The study group includes 20 cases of formalin-fixed paraffin-embedded tissue blocks of OSMF (5 cases in each grade of very early, early, moderately advanced and advanced cases of OSMF). Three-micron thick tissue sections were made from each sample and stained with 8-OHdG antibody. The results were statistically analyzed using Kruskal-Wallis and Mann-Whitney U test. RESULTS: Statistically significant difference exists in the intensity of 8-OHdG expression between the study groups. The P-value obtained was <0.001, which was highly statistically significant. CONCLUSION: The present study is the first attempt to evaluate the expression of 8-OHdG in tissue samples of OSMF that revealed the role of free radicals and oxidative DNA damage in these patients. Further research with larger sample size, clinicopathologic correlation and long-term follow-up will shed more light on the pathogenesis of OSMF. It will also be useful for the development of new therapeutic strategies targeting treatment modalities for OSMF.

Cytological intracellular glycogen evaluation using PAS and PAS-D stains to correlate plasma glucose in diabetics.

BACKGROUND: Oral cytology studies have claimed that cytoplasmic Periodic Acid Schiff (PAS) positivity in type-2 diabetics is due to glycogen content. But, it can also be due to mucin and glycoconjugates. AIM: 1. To confirm that cytoplasmic PAS positivity in type-2 diabetics is due to glycogen using diastase. 2. To know the effect of diabetes by determining the number of glycogen-containing cells in the smear. 3. To assess the impact of duration of diabetes based on PAS staining of cells. 4. To correlate between random blood glucose level and the number of PAS-positive cells. MATERIALS AND METHODS: Study population comprised 45 individuals with 30 type-2 diabetics as case group (Group I < 5 years duration; Group II > 5 years duration) and 15 healthy volunteers (age and gender-matched) as control. For all subjects, random blood glucose was estimated and two cytosmears were obtained. The smears were stained with PAS and PAS-diastase stains (PAS-D). Staining intensity was documented as score 1 (mild-to-moderate) and score 2 (moderate-to-intense) and data obtained were statistically analyzed in SPSS version 16.0. RESULTS: Mann-Whitney U test revealed that in diabetics cytoplasmic PAS positivity is because of glycogen (P < 0.05). There is an increase in the number of glycogen-containing cells (P < 0.05) in diabetics. The duration of diabetes had less impact on intracellular glycogen accumulation (P > 0.05). Spearman's correlation test revealed no significant correlation (P > 0.05) between random blood glucose and a number of PAS-positive cells. CONCLUSION: PAS positivity is because of intracellular glycogen accumulation in type-2 diabetics. It can convey the glycaemic status of an individual in the recent past, thus a beneficial role in screening and therapeutic monitoring.

Evaluation of salivary alkaline phosphatase levels in tobacco users to determine its role as a biomarker in oral potentially malignant disorders.

BACKGROUND: Elevated salivary alkaline phosphatase (S-ALP) levels have been observed in oral squamous cell carcinoma, but its status in tobacco users and in individuals with oral potentially malignant disorders (OPMDs) is less explored. AIMS AND OBJECTIVES: The aims and objectives were to estimate and compare the levels of S-ALP among tobacco users, nonusers and in individuals with OPMD. MATERIALS AND METHODS: The study population comprised 42 individuals, categorized into four groups with/without tobacco usage habit and with/without lesion. 5 ml of unstimulated saliva sample was collected, centrifuged at 3000 rpm for 15 min and supernatant separated. S-ALP was estimated in the supernatant by using kinetic photometric method in an automatic analyzer. RESULTS: Data obtained were subjected to statistical analysis. The mean S-ALP was 18.00 IU/L for normal individuals without tobacco usage, 4.60 IU/L for smokers without lesion, 7.50 IU/L for tobacco chewers without any lesion and 64.90 IU/L for individuals with OPMD. The mean difference between the groups was statistically significant (P < 0.001) using Kruskal-Wallis' ANOVA. No statistically significant difference (P > 0.05) was obtained in the S-ALP levels between tobacco users and nonusers and between smokers and tobacco chewers, using Mann-Whitney U-test. S-ALP levels in individuals with OPMD were statistically significantly higher (P < 0.001) than those without lesions, with or without tobacco usage habit, using Mann-Whitney U-test. CONCLUSION: We conclude that S-ALP could be used as a reliable noninvasive biomarker in monitoring OPMD.

Multiple myeloma involving mandible: In an elderly female.

Multiple myeloma (MM) is a malignancy of plasma cell origin. It often has a multicentric origin within the bone. It makes about 1% of all malignancies and 15% of all hematologic malignancies. There is a monoclonal proliferation of abnormal plasma cells in this disease that arise from a single malignant precursor that has undergone uncontrolled mitotic division. These cells in turn produce one type of immunoglobulin light chain, either kappa or lambda. Unifocal, monoclonal proliferation of plasma cells is called plasmacytoma. Hereby, we present a case of a 65-year-old female patient who presented with a swelling of the mandible. The uniform sheets of plasma cells in the histopathology punched out radiolucencies in skull radiograph and the blood picture of anemia and hypercalcemia, confirmed the case as MM.