Investigation of the structural,optical and gas sensing properties of PANI coated Cu–ZnS microsphere composite

Polyaniline (PANI)/Cu–ZnS composites with porous microspheres are prepared by a hydrothermal and in situ polymerization method. The structural, optical, and morphological properties are characterized by X-ray powder diffraction, FTIR, UV-vis, scanning electron microscope, transmission electron microscope. The XRD results confirmed that the PANI/Cu–ZnS composite is formed. The morphological analyses exhibited that the PANI/Cu–ZnS composite comprises the porous microspherical structures. The emission peaks obtained in photoluminescence spectra confirm the presence of surface defects in the prepared composite. The UV-DRS study shows that the bandgap of the samples is found to decrease for the PANI/Cu–ZnS composite compared to the pure Cu–ZnS sample. The calculated band gap (E_g) value of PANI/Cu–ZnS composite is 2.47 eV. Furthermore, the fabricated gas sensor based on PANI/Cu–ZnS can perform at room temperature and exhibits good gas sensing performance toward CO₂ gas. In particular, PANI/Cu–ZnS sensor shows good response (31 s) and recovery time (23 s) upon exposure to CO₂ gas. The p/n heterojunction, surface defects, and porous nature of the PANI/Cu–ZnS composite microsphere enhanced sensor performance.

Polyaniline (PANI)/Cu–ZnS composites with porous microspheres are prepared by a hydrothermal and in situ polymerization method.     

Mammalian target of rapamycin inhibition after solid organ transplantation: can it,and does it,reduce cancer risk?

The mammalian target of rapamycin (mTOR) inhibitors sirolimus and everolimus has been increasingly used as immunosuppressants for recipients of solid organ transplants. Over the years, potential advantages unique to this class of immunosuppressants have been recognized, including chemoprevention by virtue of their antiproliferative effects. Prevention of malignancy after transplant through mTOR inhibitor‐based immunosuppression may have a specific practical application in transplant recipients with preexisting malignancy including hepatocellular carcinoma or cholangiocarcinoma. This review will reveal how the biochemistry of the mTOR pathway, as it pertains to chemoprevention, can support a clinical role for mTOR inhibitors in the prevention of malignancies, recurrent or de novo, after solid organ transplantation in selected patients.     

CXCR4 homologues of gibbon ape, African green monkey, squirrel monkey, and cotton-top marmoset

CXCR4 gene homologues were isolated from an ape (gibbon), an Old World monkey (African green monkey), and two New World monkeys (squirrel monkey and cotton-top marmoset), and their DNA sequences determined. The squirrel monkey and cotton-top marmoset CXCR4 sequences more closely resemble homologues from apes than Old World monkeys, a pattern not seen for the related chemokine receptor CCR5. The African green monkey CXCR4 gene is similar to its homologue in baboon, a pattern that has also been seen among CCR5 homologues. The gibbon CXCR4 contains the first polymorphisms recognized in ape homologues, the human and chimpanzee CXCR4 proteins being identical, and two of these three differences are also observed in one or more Old World monkey homologues. While 18 positions within CXCR4 are now known to be polymorphic in primates, 7 of these polymorphisms have been observed in multiple examples and 11 have been observed only once.     

Efficacy of Human Chorion Membrane Allograft for Recession Coverage: A Case Series

Background : Membranes of human placentas have been used in the field of medicine for skin grafts, treatment of burns, and ulcerated skin conditions with great success. The use of placenta allografts in dentistry is a more recent development, with the first commercial product being made available in 2008. The unique inherent biologic properties in placenta allografts enhance wound healing and may propagate regeneration. Methods: Ten healthy adult patients presenting with 21 Miller Class I gingival recession (GR) defects (isolated or adjacent multiple) were surgically treated with a modified coronally advanced flap and chorion membrane for root coverage. Clinical parameters measured at baseline, 3 months, and 6 months were probing depth, clinical attachment level, GR height, width of keratinized gingiva, and assessment of gingival biotype. Statistical analysis was performed to compare the treatment outcomes at the follow‐up intervals. Results: The results showed statistically significant (P <0.001) improvements in all clinical parameters at the 3‐ and 6‐month follow‐ups. The mean percentage of root coverage at the end of 6 months was 89.92% ± 15.59%, and 14 of 21 treated GR defects showed 100% root coverage. The gingival biotype also showed a thick biotype in nine sites that had an initial thin biotype. Conclusions: Fetal membranes possess distinctive properties that can be harnessed to promote periodontal healing. The chorion membrane covered by a modified coronally advanced flap is a new approach that has shown promising results in terms of root coverage, increased width of keratinized tissue, and thickness of the gingival biotype.     

Coexistence of phosphotyrosine-dependent and -independent interactions between Cbl and Bcr-Abl

Cbl is one of the major tyrosine-phosphorylated proteins in Bcr-Abl-expressing cells. A direct association between the SH2 domain of Bcr-Abl and tyrosine-phosphorylated Cbl has been demonstrated. The purpose of this study was to determine if and how unphosphorylated Cbl and Bcr-Abl may associate.Interactions between Cbl and Bcr-Abl were investigated in yeast two- and three-hybrid systems, gel overlay assays, and immunoprecipitates from mammalian cells expressing wild-type and the Y177F mutant of Bcr-Abl.No direct interaction between Bcr-Abl and unphosphorylated Cbl was observed. Bcr-Abl did, however, associate with Grb2, an adaptor protein that binds tyrosine 177 of Bcr-Abl. Additionally, Grb2 interacted with Cbl. In a yeast three-hybrid assay, Grb2 mediated an interaction between Cbl and Bcr-Abl that was dependent on a functional Grb2 binding site. This interaction was confirmed in vitro using purified proteins. In cells expressing Bcr-Abl with a mutation in the Grb2 binding site, binding of Cbl to Bcr-Abl was significantly reduced, but Cbl tyrosine phosphorylation was maintained. Imatinib treatment of these cells further reduced but did not abrogate Cbl binding, reflecting residual kinase activity.Multiple phosphotyrosine-dependent and -independent interactions stabilize the interaction between Cbl and Abl. Grb2 or another, yet unidentified, protein may mediate an initial interaction between Cbl and Bcr-Abl that is independent of Cbl tyrosine phosphorylation. Following this initial interaction, Cbl can then become tyrosine phosphorylated and interact with the SH2 domain of Bcr-Abl, further stabilizing the complex.     

Gastric juice for the diagnosis of H pylori infection in patients on proton pump inhibitors

AIM： To determine the efficacy of gastric juice polymerase chain reaction （PCR） for the detection of H pylori infection in comparison with histology and gastric antral biopsy PCR in patients on a proton pump inhibitor （PPI）. METHODS： Eighty-five consecutive patients with dyspeptic symptoms were enrolled. Gastric biopsies for histology, PCR and gastric juice were collected at endoscopy for PCR of the H pylori urease C gene （ure C）. Sensitivity, specificity, positive predictive value （PPV）, negative predictive value （NPV）, accuracy, positive and negative likelihood ratio for PCR of gastric juice for the H pylori ure C gene was compared to histology and gastric antral biopsy H pylori ure C PCR in patients with and without PPI. RESULTS： Gastric juice PCR was positive in 66 （78%） patients. Histology showed H pylori associated gastritis in 57 （67%）. Gastric biopsy PCR was positive in 72 （85%）. In patients not taking PPI, the sensitivity, specificity, PPV, NPV, accuracy and positive and negative likelihood ratio for gastric juice PCR were 89%, 72%, 91%, 67%, 90%, 85%, 3.1 and 0.1 respectively. In patients on PPI these values were 86%, 100%%, 100%, 29%, 86%, 9.5 and 1.4, respectively. CONCLUSION： Gastric juice PCR for the diagnosis of H pylori infection has increased sensitivity compared to histology with PPI. The use of gastric juice PCR is recommended to confirm H pylori status in patients taking PPIs.