Brain Organoids: Expanding Our Understanding of Human Development and Disease.

Stem cell-derived brain organoids replicate important stages of the prenatal human brain development and combined with the induced pluripotent stem cell (iPSC) technology offer an unprecedented model for investigating human neurological diseases including autism and microcephaly. We describe the history and birth of organoids and their application, focusing on cerebral organoids derived from embryonic stem cells and iPSCs. We discuss new insights into organoid-based model of schizophrenia and shed light on challenges and future applications of organoid-based disease model system. This review also suggests hitherto unrevealed potential applications of organoids in combining with new technologies such as nanophotonics/optogenomics for controlling brain development and atomic force microscopy for studying mechanical forces that shape the developing brain.

Rationally designed donor-acceptor scheme based molecules for applications in opto-electronic devices.

Several donor (D)-acceptor (A) based molecules are rationally designed by adopting three different schemes in which the conjugation length, strength of the donor and acceptor moieties, and planarity of the molecules are varied. These variations are made by introducing a π-conjugated linkage unit, terminating the ends of the moieties by different electron donating and accepting functional groups, and fusing the donor and acceptor moieties, respectively. Our DFT and TDDFT based calculations reveal that using the above-mentioned design schemes, the electronic and optical properties of the D-A based molecules can be largely tuned. While introduction of a linkage and fusing of moieties enhance the π-π interaction, addition of electron donating groups (-CH3, -OH, and -NH2) and electron accepting groups (-CF3, -CN, -NO2, and -NH3(+)) varies the strength of the donor and acceptor moieties. These factors lead to modulation of the HOMO and LUMO energy levels and facilitate the engineering of the HOMO-LUMO gap and the optical gap over a wide range of ∼0.7-3.7 eV. Moreover, on the basis of calculated ionization potential and reorganization energy, most of the investigated molecules are predicted to be air stable and to exhibit high electron mobility, with the possibility of the presence of ambipolar characteristics in a few of them. The results of our calculations not only demonstrate the examined molecules to be the potential materials for organic opto-electronic devices, but also establish an understanding of the composition-structure-property correlation, which will provide guidelines for designing and synthesizing new materials of choice.

Assessment of helicobacter pylori prevalence by scorpion real-time PCR in chronic tonsillitis patients.

BACKGROUND: Occasionally, bacteria or viruses enter the tonsils and these organs become overwhelmed by bacterial or viral infection leading to inflammation. Some studies confirmed the presence of Helicobacter pylori in tonsillar specimens of patients suffering from chronic tonsillitis and some others did not. The difference in results in various studies might be due to different laboratory methods. The aim of this study was to investigate the presence of H. pylori Deoxynucleic acid (DNA) in archival tonsillar tissues of patients with chronic tonsillitis by a rapid, sensitive, and specific technique of Scorpion real-time polymerase chain reaction (PCR). MATERIALS AND METHODS: Scorpion real-time PCR and modified McMullen's staining was performed on 103 archival paraffin-embedded tonsillar samples collected from patients with chronic tonsillitis following tonsillectomy operation. RESULTS: Our findings showed that H Cell and Molecular Research Center. pylori DNA was present in 21.35% of total specimens by using Scorpion real-time PCR. Modified McMullen's staining of paraffin-embedded sections was positive in 19 patients. Out of our 103 samples, 50 samples showed positive a rapid urease test whereas 53 samples demonstrated negative results, 20 produced positive PCR results, and 83 were negative for H. pylori. There was no significant relationship between the presence of H. pylori, sex, age, and place of residence. CONCLUSION: Although the existence of H. pylori in tonsillar tissue samples of patients with chronic tonsillitis is controversial, however, our results showed that in our studied specimens, a significant number of patients with chronic tonsillitis had H. pylori colonization.