Resistance as a Cultural Universal of Human Psyche: a Dialectical View.

In its overall intent, the paper aims to instantiate the Valsinerian (2018) proposal of resistance as a fundamental process of human psyche. It attempts to use the concept of resistance to challenge the dualistic axiomatic basis of traditional psychology and argues for the benefits of dialectical metatheory in which theory of resistance is grounded. As a fundamental attribute of human functioning, resistance arises out of the tension of contradictions between opposites within the same whole. To grasp its nature and operation, the dialectical metatheory is needed rather than a dualistic metatheory which is endemic in traditional Psychology. The paper contrasts the two metatheories with each other and outlines the basic premises of dialectical metatheory. It also further elaborates the theory of resistance by addressing the three significant questions about the nature of resistance: Is resistance present in all encounters between persons and between persons and culture? Is resistance limited to negation or is it generative? Is resistance central to making development possible and bringing about transformational change? Through the application of dialectical framework in conceptualizing individual and collective relations, the dualistic thinking in cultural psychology about individualism and collectivism as mutually exclusive categories is questioned. Also, it opens out the space for finding the hidden transcripts of resistance in collectivist culture.

Comparison of the diagnostic utility of 99mTc-PSMA scintigraphy versus 68Ga-PSMA-11 PET/CT in the detection of metastatic prostate cancer and dosimetry analysis: a gamma-camera-based alternate prostate-specific membrane antigen imaging modality.

OBJECTIVE: The present study was performed for head-to-head comparison between 68Ga-prostate-specific membrane antigen (PSMA) PET/computed tomography (CT) and 99mTc-PSMA whole-body and regional single-photon emission computed tomography (SPECT)/CT for the detection of prostate cancer metastases. METHODS: Ten patients with metastatic prostate cancer underwent 99mTc-PSMA whole-body scan after intravenous injection of 230-330 MBq 99mTc-PSMA. Anterior and posterior whole-body images were acquired at 10 min, 2, 4 and/or 5/6 h post-injection. Additional SPECT/CT images were acquired for the involved sites, where planar images did not clearly identify the metastatic sites. All patients also underwent whole-body 68Ga-PSMA PET/CT and the results between the two techniques were compared for the detection of the metastatic lesions. Dosimetry analysis of the 99mTc-PSMA studies was performed using the MIRD-OLINDA approach. RESULTS: 68Ga-PSMA PET/CT detected lesions in all 10 patients, whereas 99mTc-PSMA imaging detected lesions in 9/10 patients. 68Ga-PSMA PET/CT imaging identified a total of 112 PSMA avid metastatic lesions compared to 57 (51%) lesions on 99mTc-PSMA imaging. Eighteen out of 57 lesions were detected only on delayed 99mTc-PSMA imaging at 4 h and/or 6 h. The regional 99mTc-PSMA SPECT detected 51/83 (61.0%) lesions seen on 68Ga-PSMA PET/CT. The dosimetry results demonstrated that 99mTc-PSMA provided organs' radiation absorbed/effective doses comparable with 99mTc-PSMA imaging. CONCLUSION: Whole-body 99mTc-PSMA combined with regional SPECT/CT could be a potential alternative to 68Ga-PSMA PET for the detection of the advanced stage metastatic prostate cancer and for response evaluation to PSMA-based targeted therapies.

Big and Small Stories from India in the COVID19 Plot: Directions for a 'Post Coronial' Psychology.

The paper has a dual focus. One, is to use India as a case study to reflect upon the political, economic and socio-cultural structures of the country and how they shape the particular vulnerabilities in the society which have been aggravated in the COVID19 crisis-scape. Stories about Indian democracy, Casteism and Untouchability, Hindutva and Islamophobia emerging from the pandemic scenario have been extended to show global parallels. Stories of cultural resourcefulness and examples of people's power in the Indian context have also been represented to provide a formative assessment of how India is faring in the pandemic crisis. Two, it gathers emergent questions about human and social life which are being re-emphasized and created by the pandemic for Psychology to focus on. It makes use of Indian psychological concepts to re-envision self-other relationships in Post Coronial world. It makes a plea for strengthening the critical-cultural approach in 'Post-Coronial' Psychology.

Investigating the property of water driven lead-free stable inorganic halide double perovskites.

Lead free halide double perovskite materials, A2BB́X6 (where A, B and B́ are cations and X is a halide anion) have achieved considerable attention in the field of optoelectronic devices due to their high thermal along with the moisture stability and less toxicity as lead halide perovskites suffer from the stability and toxicity issues which inhibit them to be commercialized. Therefore, synthesis of low cost and stable perovskite materials are the main focus of perovskite family nowadays. Herein, we have reported lead free Cs2AgBiCl6 and Cs2AgBiBr6 double perovskite microcrystals in both organic and a mixture of the aqueous-organic medium. Our studies are not only eradicating the toxicity of lead but also explored towards the stability of perovskite materials in the aqueous medium. Morphology is investigated using SEM and TEM imaging along with the enhancement in emission peak by increasing the content of water.

Aqueous Precursor Induced Morphological Change and Improved Water Stability of CsPbBr3 Nanocrystals.

In the literature, lead halide perovskites are very notable for their degradation in the presence of polar solvents, such as water. In contrast, in this research, it is observed that adding a minor amount of water into the precursor solution can improve the stability and photoluminescence quantum yield of CsPbBr3 nanocrystals through a ligand-assisted reprecipitation (LARP) method. In this way, the shape and phase transformation from CsPbBr3 nanoplates to CsPbBr3 /Cs4 PbBr6 nanorods and Cs4 PbBr6 nanowires can be controlled with increasing water content in the precursor solution. Upon adding water up to an ideal amount, CsPbBr3 maintains its phase and nanoplate morphology. The key role of water amount for tuning the crystallinity, stability, morphology, optical properties, and phase transformation of cesium lead halide perovskite nanocrystals will be beneficial in the future commercialization of optoelectronics.

Charge transfer between lead halide perovskite nanocrystals and single-walled carbon nanotubes.

A charge transfer study between lead halide-based perovskite nanocrystals and single-walled carbon nanotubes (PNC@CNT nanocomposite) was performed. Solution-processed MAPbX3 PNCs displayed very bright luminescence, but it quenched in the presence of CNTs. This was attributed to the electron transfer from PNCs to CNTs. The detailed changes in fluorescence lifetime were investigated through time-correlated single-photon counting (TCSPC), which suggested mixed static and dynamic quenching along with a decrease in the lifetime. Morphological changes were investigated via transmission electron microscopy (TEM) and attributed to the incorporation of PNCs on long CNTs. Also, the PNC@CNT nanocomposite was explored for photoinduced current response, which indicated an ∼3 fold increase in photoconductivity under light illumination (with a 1 mV bias). This electron transfer study between PNCs and CNTs contributes to the exploration of charge dynamics.

Nitrate Ion-Incorporated Stable Perovskite Nanocrystals by a Solvent-Free Mechanochemical Reaction.

We have synthesized a new class of organolead halide perovskite nanocrystals by a solvent-free mechanochemical green approach. We have developed a new combination of precursor by incorporating nitrate ions into the MAPbBr3 perovskite core. While the presence of nitrate ion is evidenced by Fourier-transform infrared spectra, X-ray diffraction data shows the formation of perovskite nanocrystals. By altering the precursor composition, the morphology of the nanocrystals changes. Photoluminescence properties of these nanocrystals are preserved. Moreover, the stability of these nanocrystals is monitored for a long time, which shows that the incorporation of nitrate ions into the perovskite nanocrystal core does not have any decremental effect on its stability. Nonetheless, this strategy to synthesize perovskite nanocrystals reduces the solvent toxicity.

Comparison of fluoride ion release and alkalizing potential of a new bulk-fill alkasite.

AIM: This study was conducted to evaluate and compare fluoride ion release by Cention-N (self-cure and light-cure) and conventional glass-ionomer cement (GIC) at different pH and time intervals. METHODOLOGY: Cavities of similar dimensions were prepared in mandibular molars and restored with Cention-N (by self-cure and light-cure techniques) and GIC. Samples were stored in deionized water, and the cumulative fluoride ion release and change in pH were assessed utilizing spectrophotometer and pH meter, respectively, at the end of 7 days, 14 days, and 21 days. The data thus obtained were statistically analyzed. RESULTS: All the tested materials released fluoride ions in both acidic and neutral pH at all time intervals, and the fluoride ion release was significantly higher (<0.05) in acidic pH as compared to neutral pH except in GIC. All the groups showed a statistically significant increase in pH in acidic medium, whereas no significant increase was observed in neutral medium. CONCLUSIONS: Cention-N (self-cure) has the highest fluoride ion release and alkalizing potential in acidic pH as compared to Cention-N (light-cure) and GIC.

Ultralong micro-belts of luminescent lead halide-based perovskites.

Ultralong micro-belts of MAPbI3 show bright and stable fluorescence in solution. Luminescent perovskites have been synthesized through centrifugation of a solution processed with a ligand-assisted reprecipitation technique (LARP). All electron spectroscopic analysis provided evidence for stacking of nanocrystals as bundles of self-assembled micro-belts. Under an applied bias, migration of free charge carriers through the long axis is feasible. Thus, long micro-belts are promising channel materials for two-electrode nanodevices for good electrical conductivity.

Induction of dentinal microcracks during postspace preparation: A comparative microcomputed tomography study.

INTRODUCTION: This study evaluated and compared techniques of postspace preparation for induction of dentinal microcracks utilizing microcomputed tomography (CT). MATERIALS AND METHODS: A total of 45 extracted micro-CT scanned mandibular premolars were prepared and obturated. After the second micro-CT, samples were divided into three groups (n = 15). In Group 1, postspace preparation was done using hand K files up to the size of #110. In Group 2, postspace preparation was done using Peeso reamer up to the number of #3. In Group 3, postspace preparation was done using ParaPost XT Drills with the tip diameter of 1.1 mm. Thereafter, the third micro-CT scan was performed for microcracks evaluation, and statistical analysis was performed. RESULTS: Few unprepared samples showed the presence of microcracks (1.54%). There was statistically significant (P < 0.05) percentage increase in the number of microcracks after root canal preparation and obturation (5.44%) and after postspace preparation (8.35%). The percentage increase in microcracks observed for Group 1, 2, and 3 from obturation to postspace preparation was 0.19%, 4.21%, and 6.86%. There was a significant difference among the three techniques of postspace preparation (P < 0.05). CONCLUSION: Microcracks may exist preoperatively. Postspace preparation increased the number of microcracks irrespective of the technique utilized. ParaPost XT Drills produces maximum microcracks in the root dentin followed by Peeso reamers and K files.

Effect of root canal preparation, obturation, and retreatment on the induction of dentinal microcracks: A microcomputed tomography study.

INTRODUCTION: This study evaluated the effect of root canal preparation, obturation, and different techniques of retreatment on the percentage increase in the number of dentinal microcracks using microcomputed tomography (CT) analysis. MATERIALS AND METHODS: Forty-five mandibular premolars after micro-CT scanning were prepared using Protaper universal files up to F4 and obturated. After the second micro-CT scanning again, the samples were randomly divided into three groups (n = 15) for retreatment procedure. In Group 1, retreatment was done with Protaper universal D1, D2, and D3 retreatment files followed by Protaper universal file till F4. In Group 2, retreatment was performed with R-Endo reciprocating motion, Re, R1, R2, R3, and Rs followed by Hero Shaper size #40. In Group 3, retreatment was performed with H-files and xylene till size #40. After gutta percha removal, the samples were again scanned for micro-CT for the evaluation of percentage increase in dentinal microcracks. Data were analyzed using "Kruskal-Wallis test ANOVA" and "student t-test" at 5% level of significance. RESULTS: Few unprepared samples showed preexisting microcracks. There were statistically significant percentage increase dentinal cracks after root canal preparation and obturation as well as after retreatment procedure with statistically significant percentage increase in the number of dentinal microcracks between all three groups. CONCLUSION: Intraradicular procedures such as shaping and cleaning and obturation as well as the use of retreatment file lead to the induction and propagation of dentinal microcracks. In the present study, the maximum microcracks were produced with Protaper universal retreatment file system followed by R-Endo system. H-files produced minimum cracks during retreatment procedures.

Surface modulation of solution processed organolead halide perovskite quantum dots to large nanocrystals integrated with silica gel G.

We demonstrated a facile method to grow organometal halide perovskite quantum dots in a solid silica matrix. The photoluminescence measurements of the MAPbBr3 quantum dots and corresponding large particles show a shift from blue to green emission with morphological changes. The nanocrystals impregnated on the silica matrix improve the stability and may be useful as functional materials in all solid state light emitting devices.

Four cuspal maxillary second premolar with single root and three root canals: Case report.

Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps.

An in vitro comparative evaluation of different intraorifice barriers on the fracture resistance of endodontically treated roots obturated with gutta-percha.

AIM: To compare and evaluate the root reinforcement potential of four different intraorifice barriers: Mineral trioxide aggregate (MTA), resin-modified glass ionomer cement (RMGIC), fiber-reinforced composite (FRC), and nanohybrid composite (NC). MATERIALS AND METHODS: Seventy-five mandibular premolars were decoronated to a standardized length, and prepared and obturated with gutta-percha and AH Plus sealer. Except for control specimens, the coronal 3-mm gutta-percha was removed and filled with different materials. The specimens (75) were divided into five groups (n = 15) on the basis of the intraorifice barrier material used. Group 1: MTA, Group 2: RMGIC, Group 3: FRC, Group 4: NC, Group 5: no barrier (control). Fracture resistance of the specimens was tested. RESULTS: Fracture resistance of roots was significantly affected by the type of intraorifice barrier used and the following pattern was observed: RMGIC > FRC > NC > MTA. CONCLUSION: Intraorifice barriers can be regarded as a viable choice to reduce the occurrence of postendodontic root fractures. Among the four tested materials, RMGIC showed the maximum reinforcement.

Effect of phytic acid, ethylenediaminetetraacetic acid, and chitosan solutions on microhardness of the human radicular dentin.

AIM: The purpose of this study was to evaluate the effect of phytic acid, ethylenediaminetetraacetic acid (EDTA), and chitosan solutions on the microhardness of human radicular dentin. MATERIALS AND METHODS: Thirty dentin specimens were randomly divided into three groups of 10 specimens each according to the irrigant used: G1 - 1% phytic acid, G2 - 17% EDTA, and G3 - 0.2% chitosan. A standardized volume of each chelating solution was used for 3 min. Dentin microhardness was measured before and after application at the cervical, middle, and apical levels with a Vickers indenter under a 200-g load and a 10-s dwell time. The results were analyzed using one-way analysis of variance (ANOVA) and Student's t test. RESULTS: Microhardness of the radicular dentin varied at the cervical, middle, and apical levels. EDTA had the greatest overall effect, causing a sharp percentage reduction in dentin microhardness with a significant difference from phytic acid and chitosan (P = 0.002). However, phytic acid and chitosan differed insignificantly from each other (P = 0.887). CONCLUSION: All tested chelating solutions reduced microhardness of the radicular dentin layer at all the levels. However, reduction was least at the apical level. EDTA caused more reduction in dentin microhardness than chitosan while phytic acid reduced the least.

Surgical Management of a Non-healing Intra-alveolar Root Fracture Associated with Pulpal Calcification and Root Resorption: A Case Report.

Radicular fractures are very challenging to address due to various complications like periodontal communication, increased mobility, and continued pulpal infection leading to necrosis and its long term sequelae like root resorption and pulp canal obliteration. This paper present a case of a long standing horizontal mid root fracture with root resorption and pulp canal obliteration, which was preserved functionally and aesthetically by surgical approach using MTA (mineral trioxide aggregate) and PRF (platelet rich fibrin).

Effect of technique of sealer agitation on percentage and depth of MTA Fillapex sealer penetration: A comparative in-vitro study.

AIM: To compare the effect of three root canal sealer activation techniques on percentage and depth of sealer penetration of MTA Fillapex and AH Plus sealers. MATERIALS AND METHODS: Sixty teeth prepared till F5 ProTaper size were divided into three equal groups on the basis of sealer activation technique (G1: Ultrasonics, G2: Lentulo spiral, and G3: Counter-clockwise rotary motion). Each group was further divided into two equal subgroups on the basis of type of sealer used: AH Plus (Denstply, Konstanz, Germany) or MTA Fillapex (Angelus, Londrina, PR, Brazil) and obturated with gutta-percha. Horizontal sections at 3 and 6 mm from the apex were obtained and the percentage and depth of penetration of sealers into dentinal tubules were measured using confocal laser scanning microscopy (CLSM). Statistical analysis was performed utilizing Kruskal-Wallis and Mann-Whitney U tests with a significance level of 5%. RESULTS: G1 showed significantly (P < 0.001) high percentage and depth of sealer penetration than G2 and G3 while the difference was insignificant (P > 0.05) between G2 and G3. CONCLUSION: Percentage and depth of sealer penetration are influenced by the type of sealer used sealer activation technique and by the root canal level. Ultrasonic method of sealer activation and MTA Fillapex showed the best results.

Multiple idiopathic external apical root resorption: A rare case report.

Multiple idiopathic external apical root resorption (MIEARR) is a relatively rare condition affecting multiple teeth in a dentition. As the condition is nonsymptomatic, a case is usually detected as an incidental radiographic finding. However, it may cause pain and mobility in severe cases. It is sometimes self-limiting or sometimes may progress to tooth loss. This paper presents a case of external apical root resorption involving multiple teeth in which etiology was not identified, so idiopathic root resorption was considered as a diagnosis of exclusion.

Endotracheal intubation under local anesthesia and sedation in an infant with difficult airway.

Management of the difficult airway in an infant is a challenge for the anesthesiologist. A 10-month-old infant presented to an otolaryngologist with nasopharyngeal mass since birth, which had increased rapidly in size in the last 1 month and was hanging through the cleft palate into the oropharynx. The infant was scheduled for excision of the nasopharyngeal mass through a maxillary approach and the tongue mass through an oral approach under general anesthesia. This case report describes endotracheal intubation performed successfully under sedation and local anesthesia in an infant with a nasal mass protruding through the cleft palate into the oropharynx.