Does Cavity Disinfectant Affect Sealing Ability of Universal Self-etch Adhesive?

AIM: The purpose of this study was to evaluate 2% chlorhexidine disinfectant (CHX), chitosan, and octenidine dihydrochloride (as cavity disinfectants) on microleakage in cavities restored with universal self-etch adhesive. MATERIALS AND METHODS: Eighty extracted human permanent premolars were selected. Class V cavities were prepared on the facial surface of each tooth. The teeth were then divided into four groups of 20 teeth each. For the control group after cavity preparation, no disinfectant was applied. The other 3 groups were treated with 0.1% chitosan, 2% CHX, and 0.1% octenidine dihydrochloride (OCT). All the groups were restored with universal adhesive followed by composite resin. The teeth were then immersed in 1% methylene blue dye and were sectioned buccolingually. Microleakage was checked under a stereomicroscope on both occlusal and gingival margins. RESULT: Among all the groups chitosan-treated cavities showed the least microleakage. Chlorhexidine treated cavities showed less leakage as compared to control, OCT group at both the margins. CONCLUSION: Chitosan as a cavity disinfectant improves the sealing ability of the self-etch adhesive. Furthermore, in vivo studies need to be conducted to examine the interaction and long-term effect of chitosan with the other self-etch adhesive systems. CLINICAL SIGNIFICANCE: Chitosan a natural polysaccharide can be used as a cavity disinfectant as it improves the sealing ability of self-etch adhesive.

Effect of Different Intracanal Medicaments on Apical Sealing Ability of BioRoot RCS.

AIMS AND OBJECTIVES: The aim of the present study was to determine the effect of different intracanal medicaments on the apical seal of BioRoot root canal sealer (RCS). MATERIALS AND METHODS: One hundred permanent single-rooted teeth were used in this study. All the samples were decoronated at the cementoenamel junction and instrumented in a sequential order from 15 to 50 number k-file. The specimens were randomly divided into five groups containing 20 teeth each. Intracanal medicaments used in this study were Metapex, triple antibiotic paste, Metrogyl DG gel forte (metronidazole gel 1.5% w/w), and curenext gel. For control group following instrumentation, the roots were obturated with laterally compacted gutta-percha with BioRoot RCS. In medicament groups after the period of 14 days, the medicaments were removed. All the four groups were obturated with BioRoot RCS and gutta-percha cones using lateral compaction technique. All the specimens were coated with nail varnish and immersed in 2% methylene blue. Then the specimens were demineralized and diphanized. The cleared teeth were analyzed by means of a stereomicroscope under 10× magnification. All the data were analyzed in SPSS version 18 software (IBM, Chicago, IL, USA). RESULT: Among all the intracanal medicaments, triple antibiotic paste showed the highest microleakage. When Metpaex and Metrogyl DG gel forte were compared with Curcuma longa, differences were not statistically significant. CONCLUSION: Among all the intracanal medicaments, triple antibiotic paste showed the highest microleakage and least was Metapex. CLINICAL SIGNIFICANCE: Incomplete removal of medicaments prevents the penetration of sealer into the dentinal tubules and interferes with the normal setting reaction, thus affecting the seal of obturating material leading to microleakage and subsequent treatment failure. Hence, while placing an intracanal medicament, it is important to consider its effect on leakage of the root canal system.

Impact of GSTM1, GSTT1 and GSTP1 gene polymorphism and risk of ARV-associated hepatotoxicity in HIV-infected individuals and its modulation.

Glutathione S-transferase (GST) family is involved in a two-stage detoxification process of a wide range of environmental toxins, carcinogen and antiretroviral (ARV) therapy (ART) drugs. The aim of this study is to describe the impact of genetic polymorphisms of GSTM1, GSTT1 and GSTP1-313A/G in the risk of ARV-associated hepatotoxicity in HIV-infected individuals and its modulation in hepatotoxic patients. We enrolled a total of 34 patients with hepatotoxicity, 131 HIV-infected individuals without hepatotoxicity under non-nucleoside reverse transcriptase inhibitor containing ART and 153 unrelated healthy individuals. With a case-control design, polymorphisms of GSTM1, GSTT1 and GSTP1-313A/G gene were genotyped by PCR and restriction enzyme-length polymorphism. Genotypes of GSTT1 null were significantly higher in HIV-infected individuals as compared with healthy controls (P=0.01, odds ratio (OR)=1.54). HIV-infected individuals with GSTM1-null genotype showed higher risk (P=0.09, OR=1.37) for hepatotoxicity, but risk was not significant. On evaluating gene-gene interaction models, GSTM1 null and GSTT1 null showed significant association with the risk of hepatotoxicity in HIV-infected individuals (P=0.004, OR=2.67) owing to synergistic effect of these genes. Individuals with GSTT1-null and GSTM1-null genotypes showed higher risk of hepatotoxicity with advanced stage of (CD4<200) of HIV infection (P=0.18, OR=1.39; P=0.63, OR=1.13). In case-only analysis, GSTT1-null genotype among alcohol users showed elevated risk of hepatotoxicity in HIV-infected individuals (P=0.12, OR=1.36, 95% confidence interval (CI): 0.94-1.97) as compared with GSTT1 genotypes. The carriers GSTM1-null+GSTT1-null genotype among nevirapine user showed prominent risk of hepatotoxicity in HIV-infected individuals (P=0.12, OR=4.21, 95% CI: 0.60-29.54). Hence, we can conclude that GSTT1-null and GSTM1-null genotypes alone and in combination may predict the acquisition of hepatotoxicity.

Internal electric fields in small water clusters [(H2O)n; n = 2-6].

The electric field experienced by a water molecule within a water cluster depends on its position relative to the rest of the water molecules. The stabilization energies and the red-shifts in the donor O-H stretching vibrations in the water clusters increase with the cluster size concomitant with the increase in the electric field experienced by the donor O-H of a particular water molecule due to the hydrogen bonding network. The red-shifts in O-H stretching frequencies show a spread of about ±100 cm(-1) against the corresponding electric fields. Deviations from linearity were marked in the region of 100-160 MV cm(-1), which can be attributed to the strain in the hydrogen bonding network, especially for structures with DDAA and DDA motifs. The linear Stark effect holds up to 200 MV cm(-1) of internal electric field for the average red-shifts in the O-H stretching frequencies, with a Stark tuning rate of 2.4 cm(-1) (MV cm(-1))(-1), suggesting the validity of the classical model in small water clusters.

Phenylketonuria Scientific Review Conference: state of the science and future research needs.

New developments in the treatment and management of phenylketonuria (PKU) as well as advances in molecular testing have emerged since the National Institutes of Health 2000 PKU Consensus Statement was released. An NIH State-of-the-Science Conference was convened in 2012 to address new findings, particularly the use of the medication sapropterin to treat some individuals with PKU, and to develop a research agenda. Prior to the 2012 conference, five working groups of experts and public members met over a 1-year period. The working groups addressed the following: long-term outcomes and management across the lifespan; PKU and pregnancy; diet control and management; pharmacologic interventions; and molecular testing, new technologies, and epidemiologic considerations. In a parallel and independent activity, an Evidence-based Practice Center supported by the Agency for Healthcare Research and Quality conducted a systematic review of adjuvant treatments for PKU; its conclusions were presented at the conference. The conference included the findings of the working groups, panel discussions from industry and international perspectives, and presentations on topics such as emerging treatments for PKU, transitioning to adult care, and the U.S. Food and Drug Administration regulatory perspective. Over 85 experts participated in the conference through information gathering and/or as presenters during the conference, and they reached several important conclusions. The most serious neurological impairments in PKU are preventable with current dietary treatment approaches. However, a variety of more subtle physical, cognitive, and behavioral consequences of even well-controlled PKU are now recognized. The best outcomes in maternal PKU occur when blood phenylalanine (Phe) concentrations are maintained between 120 and 360 µmol/L before and during pregnancy. The dietary management treatment goal for individuals with PKU is a blood Phe concentration between 120 and 360 µmol/L. The use of genotype information in the newborn period may yield valuable insights about the severity of the condition for infants diagnosed before maximal Phe levels are achieved. While emerging and established genotype-phenotype correlations may transform our understanding of PKU, establishing correlations with intellectual outcomes is more challenging. Regarding the use of sapropterin in PKU, there are significant gaps in predicting response to treatment; at least half of those with PKU will have either minimal or no response. A coordinated approach to PKU treatment improves long-term outcomes for those with PKU and facilitates the conduct of research to improve diagnosis and treatment. New drugs that are safe, efficacious, and impact a larger proportion of individuals with PKU are needed. However, it is imperative that treatment guidelines and the decision processes for determining access to treatments be tied to a solid evidence base with rigorous standards for robust and consistent data collection. The process that preceded the PKU State-of-the-Science Conference, the conference itself, and the identification of a research agenda have facilitated the development of clinical practice guidelines by professional organizations and serve as a model for other inborn errors of metabolism.

Dental and ENT Evaluation Before Liver Transplantation.

The assessment of dental and ear, nose and throat (ENT) conditions holds significant importance in the pre-transplantation evaluation for individuals undergoing liver transplantation. This evaluation aims to address concerns related to dental and ENT issues both before and after liver transplantation. These concerns include the risk of sepsis, the impact of post-transplantation immunosuppression, the detection of existing malignancies, including oral potentially malignant disorders (OPMDs), and identifying any contraindications to the transplantation procedure. However, it is worth noting that there exists a notable absence of clear guidelines and protocols in the existing literature regarding this practice. Moreover, recent studies have presented conflicting results, and concerns have arisen regarding the cost-effectiveness of these evaluations. It is crucial to perform these investigations judiciously to avoid unnecessary testing burdens and delays in placing patients on waiting lists, particularly when considering live donor liver transplantation (LDLT) evaluations. A comprehensive examination of the oral and ENT regions, in conjunction with relevant laboratory tests, can play a pivotal role in identifying and managing oral and ENT diseases before the liver transplantation procedure. Timely recognition and treatment of potential issues are essential for minimizing perioperative morbidity and mortality. There is an evident need for prospective trials and studies to further explore and establish guidelines in the critical area of dental and ENT evaluation in liver transplantation recipients. Such research efforts would contribute significantly to enhancing our understanding and management of oral and ENT conditions in the pre-transplantation setting, ultimately improving patient care and outcomes.

Systematic development of immunohistochemistry protocol for large cryosections-specific to non-perfused fetal brain.

BACKGROUND: Immunohistochemistry (IHC) is an important technique in understanding the expression of neurochemical molecules in the developing human brain. Despite its routine application in the research and clinical setup, the IHC protocol specific for soft fragile fetal brains that are fixed using the non-perfusion method is still limited in studying the whole brain. NEW METHOD: This study shows that the IHC protocols, using a chromogenic detection system, used in animals and adult humans are not optimal in the fetal brains. We have optimized key steps from Antigen retrieval (AR) to chromogen visualization for formalin-fixed whole-brain cryosections (20 µm) mounted on glass slides. RESULTS: We show the results from six validated, commonly used antibodies to study the fetal brain. We achieved optimal antigen retrieval with 0.1 M Boric Acid, pH 9.0 at 70°C for 20 minutes. We also present the optimal incubation duration and temperature for protein blocking and the primary antibody that results in specific antigen labeling with minimal tissue damage. COMPARISON WITH EXISTING METHODS: The IHC protocol commonly used for adult human and animal brains results in significant tissue damage in the fetal brains with little or suboptimal antigen expression. Our new method with important modifications including the temperature, duration, and choice of the alkaline buffer for AR addresses these pitfalls and provides high-quality results. CONCLUSION: The optimized IHC protocol for the developing human brain (13-22 GW) provides a high-quality, repeatable, and reliable method for studying chemoarchitecture in neurotypical and pathological conditions across different gestational ages.

Histological characterization and development of mesial surface sulci in the human brain at 13-15 gestational weeks through high-resolution histology.

Cellular-level anatomical data from early fetal brain are sparse yet critical to the understanding of neurodevelopmental disorders. We characterize the organization of the human cerebral cortex between 13 and 15 gestational weeks using high-resolution whole-brain histological data sets complimented with multimodal imaging. We observed the heretofore underrecognized, reproducible presence of infolds on the mesial surface of the cerebral hemispheres. Of note at this stage, when most of the cerebrum is occupied by lateral ventricles and the corpus callosum is incompletely developed, we postulate that these mesial infolds represent the primordial stage of cingulate, callosal, and calcarine sulci, features of mesial cortical development. Our observations are based on the multimodal approach and further include histological three-dimensional reconstruction that highlights the importance of the plane of sectioning. We describe the laminar organization of the developing cortical mantle, including these infolds from the marginal to ventricular zone, with Nissl, hematoxylin and eosin, and glial fibrillary acidic protein (GFAP) immunohistochemistry. Despite the absence of major sulci on the dorsal surface, the boundaries among the orbital, frontal, parietal, and occipital cortex were very well demarcated, primarily by the cytoarchitecture differences in the organization of the subplate (SP) and intermediate zone (IZ) in these locations. The parietal region has the thickest cortical plate (CP), SP, and IZ, whereas the orbital region shows the thinnest CP and reveals an extra cell-sparse layer above the bilaminar SP. The subcortical structures show intensely GFAP-immunolabeled soma, absent in the cerebral mantle. Our findings establish a normative neurodevelopment baseline at the early stage.

Biosynthesis of Artemisia abyssinica Leaf Extract-Mediated Bimetallic ZnO-CuO Nanoparticles: Antioxidant, Anticancer, and Molecular Docking Studies.

Currently, plant extract-mediated synthesized metal oxide nanoparticles (MO NPs) have played a substantial role in biological applications. Hence, this study focused on the eco-benign one-pot synthesis of bimetallic ZnO-CuO nanoparticles (ZC NPs) using the leaf extract of Artemisia abyssinica (LEAA) and evaluations of their anticancer, antioxidant, and molecular binding efficacy. The optical absorption peak at 380 nm from UV-visible (UV-vis) analysis revealed the formation of ZC NPs. X-ray diffraction (XRD) results revealed the fabrication of mixed-phase crystals with hexagonal and monoclinic structures of ZC NPs with an average crystallite size of 14 nm. Moreover, the biosynthesis of ZC NPs with a spherical morphology and an average particle size of 13.09 nm was confirmed by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM) results. Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA/DTA) spectroscopy confirmed the involvement of functional groups from LEAA during the synthesis of ZC NPs. ZC NPs have exhibited the ferric ion reducing power (FRAP) with an absorbance of 1.826 ± 0.00 at 200 µg/mL and DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) radical scavenging activity of 95.71 ± 0.02% at 200 µg/mL with an IC50 value of 3.28 µg/mL. Moreover, ZC NPs had shown a promising in vitro anticancer activity of 89.20 ± 0.038 at 500 µg/mL with an IC50 value of 33.12 µg/mL against breast cancer (MCF-7) cell lines. Likewise, ZC NPs have shown strong binding affinity (-8.50 kcal/mol) against estrogen receptor α (ERα) in molecular docking simulations. These findings suggested that the biosynthesized ZC NPs could be used as promising antioxidant and anticancer drug candidates, particularly for breast cancer ailments. However, the in vivo cytotoxicity test will be recommended to ensure further use of ZC NPs.

Novel pH- and temperature-responsive blend hydrogel microspheres of sodium alginate and PNIPAAm-g-GG for controlled release of isoniazid.

This paper reports the preparation and characterization of novel pH- and thermo-responsive blend hydrogel microspheres of sodium alginate (NaAlg) and poly(N-isopropylacrylamide)(PNIPAAm)-grafted-guar gum (GG) i.e., PNIPAAm-g-GG by emulsion cross-linking method using glutaraldehyde (GA) as a cross-linker. Isoniazid (INZ) was chosen as the model antituberculosis drug to achieve encapsulation up to 62%. INZ has a plasma half-life of 1.5 h, whose release was extended up to 12 h. Fourier transform infrared spectroscopy was used to confirm the grafting reaction and chemical stability of INZ during the encapsulation. Differential scanning calorimetry was used to investigate the drug's physical state, while powder X-ray diffraction confirmed the molecular level dispersion of INZ in the matrix. Scanning electron microscopy confirmed varying surface morphologies of the drug-loaded microspheres. Temperature- and pH-responsive nature of the blend hydrogel microspheres were investigated by equilibrium swelling, and in vitro release experiments were performed in pH 1.2 and pH 7.4 buffer media at 37°C as well as at 25°C. Kinetics of INZ release was analyzed by Ritger-Peppas empirical equation to compute the diffusional exponent parameter (n), whose value ranged between 0.27 and 0.58, indicating the release of INZ follows a diffusion swelling controlled release mechanism.

Exploring Klebsiella pneumoniae capsule polysaccharide proteins to design multiepitope subunit vaccine to fight against pneumonia.

BACKGROUND: Klebsiella pneumoniae is an emerging human pathogen causing neonatal lung disease, catheter-associated infections, and nosocomial outbreaks with high fatality rates. Capsular polysaccharide (CPS) protein plays a major determinant in virulence and is considered as a promising target for vaccine development. RESEARCH DESIGN AND METHODS: In this study, we used immunoinformatic approaches to design a multi-peptide vaccine against K. pneumonia. The epitopes were selected through several immune filters, such as antigenicity, conservancy, nontoxicity, non-allergenicity, binding affinity to HLA alleles, overlapping epitopes, and peptides having common epitopes. RESULTS: Finally, a construct comprising 2 B-Cell, 8 CTL, 2 HTL epitopes, along with adjuvant, linkers was designed. Peptide-HLA interaction analysis showed strong binding of these epitopes with several common HLA molecules. The in silico immune simulation and population coverage analysis of the vaccine showed its potential to evoke strong immune responses.. Further, the interaction between vaccine and immune was evaluated by docking and simulation, revealing high affinity and complex stability. Codon adaptation and in silico cloning revealed higher expression of vaccine in E. coli K12 expression system. CONCLUSIONS: Conclusively, the findings of the present study suggest that the designed novel multi-epitopic vaccine holds potential for further experimental validation against the pathogen.

Immunoinformatic approach employing modeling and simulation to design a novel vaccine construct targeting MDR efflux pumps to confer wide protection against typhoidal Salmonella serovars.

Overcoming multi drug resistance is one of the crucial challenges to control enteric typhoid fever caused by Salmonella typhi and Salmonella paratyphi. Overexpression of efflux pumps predominantly causes drug resistance in microorganisms. Therefore, immunotherapy targeting the various efflux pumps antigens could be a promising strategy to increase the success of vaccines. An immunoinformatic approach was employed to design a Salmonellosis multi-epitope subunit vaccine peptide consisting of linear B-cell and T-cell epitopes of multidrug resistance protein families including ATP Binding Cassette (ABC), major facilitator superfamily (MFS), resistance nodulation cell division (RND), small multidrug resistance (SMR), and multidrug and toxin extrusion (MATE). The selected epitopes exhibited conservation in both S. typhi and S. paratyphi and thus could be helpful for cross-protection. Further, the final vaccine construct encompassing the peptides, adjuvants and specific linker sequences showed high immunogenicity, solubility, non-allergenic, nontoxic, and wide population coverage due to strong binding affinity to maximum HLA alleles. The three-dimensional structure was predicted, and validated using various structure validation tools. Additionally, protein-protein docking of the chimeric vaccine construct with the TLR-2 protein and molecular dynamics demonstrated stable and efficient binding. Conclusively, the immunoinformatic study showed that the novel multi epitopic vaccine construct can simulate the both T-cell and B-cell immune responses in typhoidal Salmonella serovars and could potentially be used for prophylactic or therapeutic applications.Communicated by Ramaswamy H. Sarma.

Aurora Borealis in dentistry: The applications of cold plasma in biomedicine.

Plasma is regularly alluded to as the fourth form of matter. Its bounty presence in nature along with its potential antibacterial properties has made it a widely utilized disinfectant in clinical sciences. Thermal plasma and non-thermal (or cold atmospheric) plasma (NTP) are two types of plasma. Atoms and heavy particles are both available at the same temperature in thermal plasma. Cold atmospheric plasma (CAP) is intended to be non-thermal since its electrons are hotter than the heavier particles at ambient temperature. Direct barrier discharge (DBD), atmospheric plasma pressure jet (APPJ), etc. methods can be used to produce plasma, however, all follow a basic concept in their generation. This review focuses on the anticipated uses of cold atmospheric plasma in dentistry, such as its effectiveness in sterilizing dental instruments by eradicating bacteria, its advantage in dental cavity decontamination over conventional methods, root canal disinfection, its effects on tooth whitening, the benefits of plasma treatment on the success of dental implant placement, and so forth. Moreover, the limitations and probable solutions has also been anticipated. These conceivable outcomes thus have proclaimed the improvement of more up-to-date gadgets, for example, the plasma needle and plasma pen, which are efficient in treating the small areas like root canal bleaching, biofilm disruption, requiring treatment in dentistry.

Molecular Characterization and Designing of a Novel Multiepitope Vaccine Construct Against Pseudomonas aeruginosa.

ABSTRACT: Pseudomonas aeruginosa, an ESKAPE pathogen causes many fatal clinical diseases in humans across the globe. Despite an increase in clinical instances of Pseudomonas infection, there is currently no effective vaccine or treatment available. The major membrane protein candidate of the P. aeruginosa bacterial cell is known to be a critical component for cellular bacterial susceptibility to antimicrobial peptides and survival inside the host organisms. Therefore, the current computational study aims to examine P. aeruginosa's major membrane protein, OprF, and OprI, in order to design linear B-cell, cytotoxic T-cell, and helper T-cell peptide-based vaccine constructs. Utilizing various immune-informatics tools and databases, a total of two B-cells and twelve T-cells peptides were predicted. The final vaccine design was simulated to generate a high-quality three-dimensional structure, which included epitopes, adjuvant, and linkers. The vaccine was shown to be nonallergenic, antigenic, soluble, and had the best biophysical properties. The vaccine and Toll-like receptor 4 have a strong and stable interaction, according to protein-protein docking and molecular dynamics simulations. Additionally, in silico cloning was employed to see how the developed vaccine expressed in the pET28a (+) vector. Ultimately, an immune simulation was performed to see the vaccine efficacy. In conclusion, the newly developed vaccine appears to be a promising option for a vaccine against P. aeruginosa infection. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10989-021-10356-z.

Effect of temperature and activation techniques of irrigating solutions on push-out bond strength of fiber post.

AIM: This study evaluated the effect of preheated irrigants (EDTA, QMix), then use of various activation techniques such as ultrasonic system and laser on push-out bond strength (POBS) of fiber posts to root dentin. METHODOLOGY: One hundred and twenty extracted human teeth were decoronated below the cementoenamel junction. All the root canals were instrumented, irrigated using sodium hypochlorite and normal saline, dried with paper points, and filled with gutta-percha and AH Plus sealer. Post spaces were prepared. The irrigating solutions QMix and EDTA were heated to 60°C. Normal QMix and EDTA served as control. The irrigants were activated with Laser and Ultrasonic system. Then, the fiber posts were cemented, roots were sliced to thickness of 2 mm and mounted for measurement of POBS. RESULTS: Preheated irrigants group showed maximum POBS as compared to Normal irrigants. QMix group showed better results as compared to EDTA. Irrigants when activated with laser and ultrasonics showed comparable results. CONCLUSION: Within the limitations of the study, it can be concluded that preheated irrigants(QMix, EDTA) increase the POBS of fiber post to root dentin. Both laser and ultrasonic are equally effective for increasing the POBS.

Externally predictive quantum-mechanical models for the adsorption of aromatic organic compounds by graphene-oxide nanomaterials.

Graphene oxide is most often chosen as an alternative to graphene in the applications of carbon-based nanomaterials where adsorption is the primary process. However, its adsorption properties are poorly understood. The existing reports on the adsorption mechanism of graphene oxide rely on the linear free-energy/solvation-energy relationship (LFER/LSER) models. This computational work explores the role of quantum mechanical descriptors in the adsorption of aromatic organic compounds by graphene-oxide. For this, externally predictive quantitative models based on quantum-mechanical descriptors are developed and compared with the existing LSERs for the prediction of adsorption coefficients of organic compounds at three different adsorbate concentrations. The predictivity of the models is assessed using an external prediction set of compounds not used for developing the models. Notably, the mean polarizability, but originating from the quantum mechanical exchange interactions (between electrons of parallel spin), is found to be the most significant factor in driving the adsorption on graphene oxide. The present work also proposes quantum-mechanical-LSER models based on a combination of quantum-mechanical and LSER descriptors, which are in fact found to be equally predictive as the existing LSERs. The quantum-mechanical models proposed in this work are further utilized for the prediction of adsorption coefficients of aliphatic compounds.

Quantum-mechanical LSERs for the concentration-dependent adsorption of aromatic organic compounds by activated carbon: Applications and comparison with carbon nanotubes.

Carbon nanotubes (CNTs) have taken precedence over activated carbon in various applications where adsorption is the primary process. The adsorption of chemical compounds by CNTs and activated carbon is most often predicted through linear free energy/solvation energy relationships (LFERs/LSERs). This work proposes quantum-mechanical LSER models based on a combination of quantum-mechanical descriptors and solvatochromic descriptors of LSERs for predicting the adsorption of aromatic organic compounds by activated carbon at varying adsorbate concentrations. The models are validated using state-of-the-art procedures employing an external prediction set of compounds. This work reveals the hydrogen bond donating and accepting ability of compounds to be the most influencing - but a negative - factor in the adsorption process of activated carbon. The quantum-mechanical LSERs proposed in this work are analysed and found to be equally reliable as the existing LSERs. These were further used to predict the adsorption of nucleobases, steroid hormones, agrochemicals, endocrine disruptors and pharmaceutical drugs. Notably, agrochemicals and endocrine disruptors are predicted to be adsorbed more strongly by activated carbon when compared with their adsorption by CNTs. However, quantum-mechanical LSERs predict the adsorption strength of biomolecules on activated carbon to be similar to that on the CNTs, which can be used to assess the risk associated with using carbon materials.

IgA nephropathy and small cell lung carcinoma.

The occurrence of glomerular disease as a paraneoplastic manifestation of malignancy is well documented in the medical literature. The strongest association is between membranous glomerulonephritis and solid tumors. We report a patient with IgA nephropathy associated with small cell lung cancer. To our knowledge, this is the second documented occurrence of an IgA nephropathy with a casual association with small cell bronchogenic cancer. This observation leads to the hypothesis that IgA nephropathy might be a paraneoplastic manifestation of this histiologic type of lung cancer.

Comparative evaluation of dentinal crack formation after root canal preparation using ProTaper Next, OneShape, and Hyflex EDM.

INTRODUCTION: The purpose of this study was to compare the incidence of dentinal crack formation after root canal preparation using ProTaper Next, OneShape, and Hyflex electrodischarge machining (HEDM). MATERIALS AND METHODS: A total of 75 extracted mandibular premolars were selected. The root canals were instrumented using ProTaper Next, OneShape, and HEDM rotary files. All roots were horizontally sectioned at 3, 6, and 9 mm from apex with slow-speed saw under water cooling. The sections were observed under a stereomicroscope at ×25 to determine the absence or presence of crack. Data were analyzed using post hoc test and one-way ANOVA. RESULTS: ProTaper Next and HEDM produced significantly less cracks than OneShape. CONCLUSION: Within the limitation of this in vitro study, it can be concluded that nickel-titanium instruments may cause cracks on the root surface. ProTaper Next and HEDM tend to produce less number of cracks as compared to OneShape.