Anharmonic phonon coupling in vapor-liquid-solid grown ZnO nanowires

We have determined quantitatively third-order anharmonic phonon coupling matrix elements in vapor-liquid-solid (VLS) grown ZnO nanowires, via an analysis of the Raman line shape of the E2high phonon mode. The results suggest that the decay of the E2high phonon into the sum of two acoustic phonons is suppressed in VLS-grown ZnO nanowires compared to bulk ZnO. While further studies are needed to elucidate the origin of this phenomenon, we suggest that isotope effects on Zn vapor transport and diffusion through metal nanocatalysts, processes during the VLS growth, can be contributing mechanisms

Multi-scale evolution of charmed particles in a nuclear medium

Parton energy-momentum exchange with the quark gluon plasma (QGP) is a multi-scale problem. In this work, we calculate the interaction of charm quarks with the QGP within the higher twist formalism at high virtuality and high energy using the MATTER model, while the low virtuality and high energy portion is treated via a (linearized) Boltzmann Transport (LBT) formalism. Coherence effect that reduces the medium-induced emission rate in the MATTER model is also taken into account. The interplay between these two formalisms is studied in detail and used to produce a good description of the D-meson and charged hadron nuclear modification factor RAA across multiple centralities. All calculations were carried out utilizing the JETSCAPE framework

Persistent postmating, prezygotic reproductive isolation between populations

Studying reproductive barriers between populations of the same species is critical to understand how speciation may proceed. Growing evidence suggests postmating, prezygotic (PMPZ) reproductive barriers play an important role in the evolution of early taxonomic divergence. However, the contribution of PMPZ isolation to speciation is typically studied between species in which barriers that maintain isolation may not be those that contributed to reduced gene flow between populations. Moreover, in internally fertilizing animals, PMPZ isolation is related to male ejaculate—female reproductive tract incompatibilities but few studies have examined how mating history of the sexes can affect the strength of PMPZ isolation and the extent to which PMPZ isolation is repeatable or restricted to particular interacting genotypes. We addressed these outstanding questions using multiple populations of Drosophila montana. We show a recurrent pattern of PMPZ isolation, with flies from one population exhibiting reproductive incompatibility in crosses with all three other populations, while those three populations were fully fertile with each other. Reproductive incompatibility is due to lack of fertilization and is asymmetrical, affecting female fitness more than males. There was no effect of male or female mating history on reproductive incompatibility, indicating that PMPZ isolation persists between populations. We found no evidence of variability in fertilization outcomes attributable to different female × male genotype interactions, and in combination with our other results, suggests that PMPZ isolation is not driven by idiosyncratic genotype × genotype interactions. Our results show PMPZ isolation as a strong, consistent barrier to gene flow early during speciation and suggest several targets of selection known to affect ejaculate‐female reproductive tract interactions within species that may cause this PMPZ isolation

Choroidal metastasis: Clinical aspects at a referral ocular oncology center

Purpose: To report clinical aspects of choroidal metastasis at an ocular oncology referral center Methods: We reviewed the records of all patients with choroidal metastasis referred to an ocular oncology referral center over a 10-year period retrospectively. The study was performed to identify and analyze clinical presentations and features of patients with choroidal metastasis. Results: A total of 113 choroidal metastases were diagnosed in 60 eyes of 48 consecutive patients. There were 17 male (35.4) and 31 female (64.6) patients with a mean age of 54.5 years (median: 42; range, 29- 82 years) at the time of choroidal metastasis diagnosis. The median and mean numbers of choroidal metastasis were one and three tumors in each eye respectively. The primary cancer location was found to be the breast in 18 patients (37.5), lung in 11 (22.9), lymphoproliferative system in three (6.3), thyroid in three (6.3), gastrointestinal tract in three (6.3), prostate in two (4.2), brain in one (2.1) and unknown primary in seven (14.5). The most common primary cancer was the breast in females and lung in males. The main ocular symptoms of choroidal metastasis at diagnosis were blurred vision in 42 patients followed by pain in five patients. The choroidal metastasis was unilateral in 36 patients (75) and bilateral in 12 patients (25). Conclusion: The clinical features and primary sites of choroidal metastasis in Iranian patients were similar to those of published reports in this regard. One out of every seven patients had no known primary cancer at the time of choroidal metastasis presentation. © 2013 by the Iranian Society of Ophthalmology

Pd (II)-promoted base hydrolysis of 2-cyano-1,10-phenanthroline

625-627Pd (II)-promoted base hydrolysis of 2-cyano-1,10-phenanthroline  has been studied. The reaction is first order each in metal-substrate complex and in hydroxide ion. The second order rate constant for Pd (II)-catalysis process is more than 105 that for alkaline hydrolysis in the absence of nickel ion. The mechanistic studies of this reaction are very interesting and give some result in spite of the nickel ion catalysing mechanism. The entire acceleration is accounted for by decreasing the ΔH#. The mechanism of metal-catalysed addition to the nitrile involves one step external attack rather than the attack of nucleophile from the metal coordination sphere

Vibrio cholerae toxin coregulated pilus provokes inflammatory responses in Coculture model of Caco-2 and peripheral blood mononuclear cells (PBMC) leading to increased colonization

The aim of this study was to assess the modulatory effect of TcpA in the expression of CEACAM1 adhesin molecule and IL-1, IL-8, and TNF-α pro-inflammatory cytokines in the Coculture model of Caco-2/PBMC (peripheral blood mononuclear cell) that can mimic the intestinal milieu. The TcpA gene from Vibrio cholerae ATCC14035 was cloned in pET-28a and transformed into Escherichia coli Bl-21. The recombinant TcpA-His6 protein was expressed and purified using Ni-column chromatography. The sequencing of transformed plasmid and Western blot analysis of purified protein confirmed the identity of rTcp. The cytotoxicity of different concentrations of recombinant protein for human colon carcinoma cell line (human colorectal adenocarcinoma cell Caco-2 cell) was assessed by MTT assay and showed viability of 92%, 82%, and 70%, for 10 µg/mL of TcpA after 24, 48, and 72 h, respectively. Co-cultures of Caco-2 and PBMCs were used to mimic the intestinal milieu and treated with different concentrations of rTcpA (1, 5, 10, and 50 µg/mL). Our data showed about 2.04-, 3.37-, 3.68-, and 42.7-fold increase in CEACAM1 gene expression, respectively, compared with the nontreated Caco-2/PBMC Coculture. Moreover, the expression of IL-1, IL-8, and TNF-α genes was significantly increased up to 15.75-, 7.04-, and 80.95-folds, respectively. In conclusion, V. cholerae TcpA induces statistically significant dose-dependent stimulatory effect on TNF-α, IL-,1, and IL-8 pro-inflammatory cytokines expression. Of these, TNF-α was much more affected which, consequently, elevated the CEACAM1 expression level in IECs. This suggests that TcpA protein is a critical effector as an inducer of increased adhesion potential of V. cholera as well as inflammatory responses of host intestinal tissue. © 2021 The Societies and John Wiley & Sons Australia, Lt

Effect of photorefractive keratectomy on optic nerve head topography and retinal nerve fiber layer thickness measured by heidelberg retina tomograph 3

Purpose: To determine whether photorefractive keratectomy (PRK) has a significant effect on optic nerve head (ONH) parameters and peripapillary retinal nerve fiber layer (RNFL) thickness measured by the Heidelberg Retina Tomograph 3 (Heidelberg Engineering GmbH, Heidelberg, Germany) in eyes with low to moderate myopia. Methods: This prospective, interventional case series, includes 43 consecutive myopic eyes which were assessed on the day of PRK and 3 months postoperatively using the HRT3. Among the stereometric parameters, we compared disc area, linear cup disc ratio, cup shape measure, global rim area, global rim volume, RNFL height variation contour and mean RNFL thickness; out of the Glaucoma Probability Score (GPS) we assessed changes in global value, rim steepness temporal/superior, and temporal/inferior, as well as cup size and cup depth before and after PRK. Results: Mean refractive error before and after PRK were -3.24 ± 1.31 and -0.20 ± 0.42 diopters, respectively. No significant change occurred in disc area, linear cup disc ratio, cup shape measure, rim area and rim volume among the stereometric parameters; and in rim steepness temporal/superior and rim steepness temporal/inferior in the GPS before and after PRK using the default average keratometry. However, RNFL height variation contour, mean RNFL thickness, and cup size and depth were significantly altered after PRK (P < 0.05). Conclusion: PRK can affect some HRT3 parameters. Although the most important stereometric parameters for differentiating normal, suspect or glaucomatous patients such as rim and cup measurements in stereometric parameters were not changed. © 2016 Journal of Ophthalmic and Vision Research