Amelogenesis Imperfecta and Distal Renal Tubular Acidosis: A Case Report.

Amelogenesis imperfecta (AI) is an inherited dental condition affecting enamel, which can result in significant tooth discoloration and enamel breakdown, requiring lifelong dental care. Distal renal tubular acidosis (dRTA) is a condition in which the kidneys are unable to acidify the urine to a pH < 5.5 in the presence of systemic metabolic acidosis. Management of AI and dRTA patients requires both medical and dental expertise to achieve long-term successful results. The aim of this paper is to present the dental management of a child with AI and dRTA. How to cite this article: Nadaf N, Krishnapriya V, Chandra A, et al. Amelogenesis Imperfecta and Distal Renal Tubular Acidosis. Int J Clin Pediatr Dent 2022;15(1):121-123.

Traumatogenic Occlusion in a Pediatric Dental Patient: A Case Report.

Aim and objective: This case report aims to describe the management of mandibular anterior teeth subjected to occlusal trauma. Background: Occlusal trauma occurs as a result of reduced ability of the tissues to resist the occlusal forces most likely as a result of masticatory system dysfunction abnormal contact of the teeth, and prosthetic or orthodontic treatments that create occlusal interferences. Case description: This paper describes a case of traumatogenic occlusion seen in the dentition of a 13-year-old female patient and its management by stabilization, endodontic, and orthodontic therapy. Conclusion: The removal of the anomalous occlusal forces and stabilization of the affected teeth is the most relevant therapy for teeth affected by trauma from occlusion (TFO). Clinical Significance: Periodic monitoring of developing occlusion contributes to preventive care and encourages the maintenance of a healthy periodontium. How to cite this article: Kartha S, Vellore KP, Challa SK, et al. Traumatogenic Occlusion in a Pediatric Dental Patient: A Case Report. Int J Clin Pediatr Dent 2022;15(2):222-226.

Agenesis of Permanent Mandibular Central Incisors: A Concordant Condition in Siblings.

Concordance is an identical expression of phenotype in two related individuals. Concordance expression of hypodontia is an uncommon condition where associated individuals are affected with exactly similar kind and number of missing teeth. There is very limited documentation of this condition either in twins or in siblings, and literature shows paucity of data with regard to this anomaly. To the best of our knowledge, there is only one such case reported in the literature, which has actually showed similar missing lower central incisors in siblings. This report presents a case of two girl siblings aged 11 and 13 years with congenital bilateral missing of permanent mandibular central incisors, which is an absolute concordant condition. Apart from discussing etiology, clinical implications and management, this article highlights the significance of concordant and discordant condition of hypodontia and expression of this condition in twins and siblings. How to cite this article: Kagitha PK, Namineni S, Tupalli AR, Challa SK. Agenesis of Permanent Mandibular Central Incisors: A Concordant Condition in Siblings. Int J Clin Pediatr Dent 2016;9(1):74-77.

Ephedrinium-based protic chiral ionic liquids for enantiomeric recognition.

We report the synthesis of a series of novel structurally related protic chiral ionic liquids (PCILs) derived from ephedrines. Enantiopure norephedrine, ephedrine, and methylephedrine were neutralized by use of fluorinated acids, bis(trifluoromethanesulfonyl)imide, and bis(pentafluoroethanesulfonyl)imide to afford six PCILs with protonated primary, secondary, and tertiary amines. The goal of this study is to investigate the influence of structure on both chiral recognition abilities and physicochemical properties of these closely related PCILs. The newly synthesized PCILs were characterized by use of nuclear magnetic resonance (NMR), thermal gravimetric analysis, differential scanning calorimetry, circular dichroism (CD), mass spectrometry, and elemental analysis. The PCILs were thermally stable up to 220°C and had glass transition temperatures between -60 and -30°C. Both enantiomers of the PCILs retained chirality throughout the synthesis as demonstrated by use of CD measurements. More interestingly, these ephedrinium PCILs displayed strong chiral recognition capabilities as evidenced by peak splitting of the chemical shift of the trifluoro group of potassium Mosher's salt by use of (19)F-NMR. In addition, these PCILs demonstrated enantiomeric recognition capabilities toward a range of structurally diverse analytes using steady-state fluorescence spectroscopy.

Lanthanide-based luminescent NanoGUMBOS.

Lanthanide photochemistry has been frequently studied for its high luminescence intensity, narrow emission band, and stable luminescent lifetime decay. In the work presented here, nanoparticles prepared using an aerosolization process were derived from europium-based GUMBOS (Group of Uniform Material Based on Organic Salts). These nanoparticles were characterized using electron microscopy, X-ray photoelectron spectroscopy (XPS), absorbance, and photoluminescence spectroscopy. An average diameter of 39.5 ± 8.4 nm for our nanoparticles was estimated by use of electron microscopy. Absorbance, luminescence, and luminescence lifetime decay measurements indicate intense and steady luminescence, which suggests a multitude of possible applications for lanthanide-based GUMBOS, especially in sensory devices, OLEDs, and photovoltaic devices.

Nontemplated approach to tuning the spectral properties of cyanine-based fluorescent nanoGUMBOS.

Template-free controlled aggregation and spectral properties in fluorescent organic nanoparticles (FONs) is highly desirable for various applications. Herein, we report a nontemplated method for controlling the aggregation in near-infrared (NIR) cyanine-based nanoparticles derived from a group of uniform materials based on organic salts (GUMBOS). Cationic heptamethine cyanine dye 1,1',3,3,3',3'-hexamethylindotricarbocyanine (HMT) was coupled with five different anions, viz., [NTf(2)(-)], [BETI(-)], [TFPB(-)], [AOT(-)], and [TFP4B(-)], by an ion-exchange method to obtain the respective GUMBOS. The nanoGUMBOS obtained via a reprecipitation method were primarily amorphous and spherical (30-100 nm) as suggested by selected area electron diffraction (SAED) and transmission electron microscopy (TEM). The formation of tunable self-assemblies within the nanoGUMBOS was characterized using absorption and fluorescence spectroscopy in conjunction with molecular dynamics simulations. Counterion-controlled spectral properties observed in the nanoGUMBOS were attributed to variations in J/H ratios with different anions. Association with the [AOT(-)] anion afforded predominant J aggregation enabling the highest fluorescence intensity, whereas [TFP4B(-)] disabled the fluorescence due to predominant H aggregation in the nanoparticles. Analyses of the stacking angle of the cations based on molecular dynamic simulation results in [HMT][NTf(2)], [HMT][BETI], and [HMT][AOT] dispersed in water and a visual analysis of the representative simulation snapshots also imply that the type of aggregation was controlled through the counterion associated with the dye cation.

Amino Acid-based fluorescent chiral ionic liquid for enantiomeric recognition.

We report on the synthesis and characterization of a new fluorescent chiral ionic liquid (FCIL), l-phenylalanine ethyl ester bis(trifluoromethane) sulfonimide (l-PheC(2)NTf(2)), capable of serving simultaneously as solvent, chiral selector, and fluorescent reporter in chiral analytical measurements. Enantiomers of different analytes, including fluorescent and nonfluorescent compounds, with a variety of structures were shown to induce wavelength- and analyte-dependent changes in the fluorescence intensity of this FCIL. This system may provide both chemo- and enantioselectivity toward multiple analytes simultaneously. The newly synthesized FCIL, derived from commercially available l-phenylalanine ethyl ester chloride and lithium bis(trifluoromethane) sulfonamide, was obtained as liquid at room temperature and is stable to thermal decomposition up to 270 degrees C. Absorption and fluorescence properties of neat l-PheC(2)NTf(2) were complex. While the absorption properties were similar to phenylalanine with a weakly absorbing tail extending beyond 400 nm, multiple excitation and emission bands were observed in its Excitation-Emission Matrix (EEM). A prominent excimer emission displayed the greatest intensity of all emission bands, and a long-wavelength emission shifted toward the red with increasing excitation wavelength. These different spectral regions were shown to respond differently toward several analytes, including sugars such as glucose and mannose, making this an ideal system to exploit the multidimensional properties of fluorescence. The unique properties of l-PheC(2)NTf(2) combined with EEMs resulted in reliable identification of different enantiomers and measurement of enantiomeric composition. Importantly, the choice of excitation and emission wavelength regions was an important variable shown to improve prediction of enantiomeric composition.

Near-infrared fluorescent nanoGUMBOS for biomedical imaging.

Herein, we report on near-infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 degrees C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS.

Molecular state and distribution of fullerenes entrapped in sol-gel samples.

A novel synthetic method that can encapsulate fullerene molecules (pure C60, pure C70, or their mixture) over a wide range of concentrations ranging from micromolar to millimolar in hybrid glass by a sol-gel method without any time-consuming, complicated, and unwanted extra steps (e.g., addition of a surfactant or derivatization of the fullerenes) has been successfully developed. The molecular state and distribution of encapsulated fullerene molecules in these sol-gel samples were unequivocally characterized using newly developed multispectral imaging techniques. The high sensitivity (single-pixel resolution) and ability of these instruments to record multispectral images at different spatial resolutions (approximately 10 microm with the macroscopic instrument and approximately 0.8 microm with the microscopic instrument) make them uniquely suited for this task. Specifically, the imaging instruments can be used to simultaneously measure multispectral images of sol-gel-encapsulated C60 and C70 molecules at many different positions within a sol-gel sample in an area either as large as 3 mm x 4 mm (with the macroscopic imaging instrument) or as small as 0.8 microm x 0.8 microm (with the microscopic instrument). The absorption spectrum of the fullerene molecule at each position can then be calculated either by averaging the intensity of a 15 x 15 square of pixels (which corresponds to an area of 3 mm x 4 mm) or from the intensity of a single pixel (i.e., an area of about 0.8 microm x 0.8 microm), respectively. The molecular state and distribution of fullerene molecules within sol-gel samples can then be determined from the calculated spectra. It was found that spectra of encapsulated C60 and C70 measured at five different positions within a sol-gel sample were similar not only to one another but also to spectra measured at six different times during the sol-gel reaction process (from t = 0 to 10 days). Furthermore, these spectra are similar to the corresponding spectra of monomeric C60 or C70 molecules in solution. Similarly, spectra of sol-gel samples containing a mixture of C60 and C70 were found to be the same at five different positions, as well as similar to spectra calculated from an average of the spectra of C60 and C70 either encapsulated in a sol-gel or in solution. It is evident from these results that C60 and C70 molecules do not undergo aggregation upon encapsulation into a sol-gel but rather remain in their monomeric state. Furthermore, entrapped C60 and C70 molecules in their monomeric state were distributed homogeneously throughout the entire sol-gel samples. Such a conclusion can be readily, quickly, and easily obtained, not with traditional spectroscopic techniques based on the use of a single-channel detector (absorption, fluorescence, infrared, Raman) but rather with the newly developed multispectral imaging technique. More importantly, the novel synthetic method reported here makes it possible, for the first time, to homogenously entrap monomeric fullerene molecules (C60, C70, or their mixture) in a sol-gel at various concentrations ranging from as low as 2.2 mM C60 (or 190 microM C70) to as high as 4.2 mM C60 (or 360 microM C70).

Fullerene-impregnated ionic liquid stationary phases for gas chromatography.

A new method has been developed to facilitate the use of fullerenes as stationary phases (SPs) in gas chromatography (GC). In this method, ionic liquids (ILs) are used as solvents to coat fullerenes (C(60), amino-C(60) and hydroxy-C(60)) onto GC columns. However, the ILs serve not just as coating solvents but also act synergistically with fullerenes to provide unique properties as stationary phases, namely dual modal characteristics. They act as non-polar SPs when separating non-polar analytes (aromatic hydrocarbon mixtures and alkane mixtures), and as polar SPs for polar analytes (e.g., alcohol mixtures). The polarity of the stationary phase can be adjusted by changing either the type of the IL and/or by adding either C(60) (or its amino or hydroxy derivatives) to the IL. It was found that C(60) and its derivatives produce not only a change in the polarity of the SP but also substantial enhancement in separation efficiencies for both non-polar and polar analytes. More importantly, when added to the IL SP, C(60) improves separation efficiencies not just for non-polar analytes (aromatic hydrocarbon mixtures and alkane mixtures) but also for polar analytes (mixtures of ortho-, meta- and para-xylene and alcohol mixtures) as well. Moreover, C(60) SP provides higher efficiencies than amino-C(60) and hydroxy-C(60) for separation of polar analytes. This is rather surprising considering that not only are amino-C(60) and hydroxy-C(60) more polar than C(60), but that the IL used to coat the amino- and hydroxy-C(60) (i.e., N-ethylpyridinium trifluoroacetate, [EtPy(+) CF(3)COO(-)]) is more polar than the IL used to coat the C(60) (i.e., octylmethylimidazolium bis(trifluoromethyl)sulfonyl)amide], [OMIm(+) (CF(3)SO(2))(2)N(-)]). Moreover, compared to its amino and hydroxy derivatives, the concentration of C(60) in the column was 10 times lower.

Near-infrared spectrophotometric determination of compositions of fullerene samples.

A novel method has been developed for the sensitive and accurate determination of compositions of fullerene samples. The method is based on the synergistic use of spectrophotometric measurements and partial least square method. The method is not only simple, inexpensive and fast but also is non-destructive. Compositions of various fullerene samples including fullerite which is the precursor to C(60) and C(70), can be directly and non-destructively determined by this method without any time-consuming separation step as in the HPLC method or destruction as in the MS method.

Ionic liquids as an attractive alternative solvent for thermal lens measurements.

The use of ionic liquids (ILs) as a solvent for thermal lens measurements has been investigated. It was found that ILs provide a better medium for thermal lens measurements than water. Specifically, not only the ILs offer at least 20 times higher sensitivity than water but that the enhancement can be appropriately adjusted by changing either the cation or the anion of the ILs. For example, the sensitivity in [BMIm]+[Tf2N]- is approximately 26 times higher than in water. It can be increased up to 31 times by changing the anion to [PF6]- (i.e., [BMIm]+[PF6]-) or to 35 times by changing the cation to [OMIm]+ (i.e., [OMIm]+[Tf2N]-). In fact, the sensitivity of thermal lens measurements in ILs is comparable to those in volatile organic solvents such as benzene, carbon tetrachloride, and hexane. However, the ILs are more desirable as they have virtually no vapor pressure. Furthermore, additional sensitivity enhancement (up to 42 times higher than that in water) can be achieved by simply adding surfactants into the ILs. Based on the thermal conductivity (k) and dn/dT values, calculated from the measured thermal time constant tc and thermal lens strength theta, it is evident that the observed sensitivity enhancement by the ILs is due to their relatively better thermooptical properties. More specifically, the enhancement is due not to the relatively modest lowering of the thermal conductivity but rather to the substantial increase in their dn/dT values. Because of the relationship between dn/dT and drho/dT, it is expected that ILs can serve as an attractive and superior solvent not only for thermal lens measurements but also for other photothermal and photoacoustic techniques as well. Also equally important is the fact that the thermal lens technique in particular and photothermal techniques, in general, can offer a unique means to determine themooptical and thermal physical properties of the ILs (e.g., thermal conductivity, thermal diffusivity, and phase transition temperatures). This type of data is currently lacking but is of extreme importance for implementing ILs as a solvent in various industrial applications.