Kinetics of n-Butoxy and 2-Pentoxy Isomerization and Detection of Primary Products by Infrared Cavity Ringdown Spectroscopy

The primary products of n-butoxy and 2-pentoxy isomerization in the presence and absence of O_2 have been detected using pulsed laser photolysis-cavity ringdown spectroscopy (PLP-CRDS). Alkoxy radicals n-butoxy and 2-pentoxy were generated by photolysis of alkyl nitrite precursors (n-butyl nitrite or 2-pentyl nitrite, respectively), and the isomerization products with and without O_2 were detected by infrared cavity ringdown spectroscopy 20 μs after the photolysis. We report the mid-IR OH stretch (ν_1) absorption spectra for δ-HO-1-C_4H_8•, δ-HO-1-C_4H_8OO•, δ-HO-1-C_5H_(10)•, and δ-HO-1-C_5H_(10)OO•. The observed ν_1 bands are similar in position and shape to the related alcohols (n-butanol and 2-pentanol), although the HOROO• absorption is slightly stronger than the HOR• absorption. We determined the rate of isomerization relative to reaction with O_2 for the n-butoxy and 2-pentoxy radicals by measuring the relative ν_1 absorbance of HOROO• as a function of [O_2]. At 295 K and 670 Torr of N_2 or N_2/O_2, we found rate constant ratios of k_(isom)/k_(O2) = 1.7 (±0.1) × 10^(19) cm^(–3) for n-butoxy and k_(isom)/k_(O2) = 3.4(±0.4) × 10^(19) cm^(–3) for 2-pentoxy (2σ uncertainty). Using currently known rate constants k_(O2), we estimate isomerization rates of k_(isom) = 2.4 (±1.2) × 10^5 s^(–1) and k_(isom) ≈ 3 × 10^5 s^(–1) for n-butoxy and 2-pentoxy radicals, respectively, where the uncertainties are primarily due to uncertainties in k_(O2). Because isomerization is predicted to be in the high pressure limit at 670 Torr, these relative rates are expected to be the same at atmospheric pressure. Our results include corrections for prompt isomerization of hot nascent alkoxy radicals as well as reaction with background NO and unimolecular alkoxy decomposition. We estimate prompt isomerization yields under our conditions of 4 ± 2% and 5 ± 2% for n-butoxy and 2-pentoxy formed from photolysis of the alkyl nitrites at 351 nm. Our measured relative rate values are in good agreement with and more precise than previous end-product analysis studies conducted on the n-butoxy and 2-pentoxy systems. We show that reactions typically neglected in the analysis of alkoxy relative kinetics (decomposition, recombination with NO, and prompt isomerization) may need to be included to obtain accurate values of k_(isom)/k_(O2)

Reconfiguration and the reduction of vortex-induced vibrations in broad leaves

Flexible plants, fungi and sessile animals reconfigure in wind and water to reduce the drag acting upon them. In strong winds and flood waters, for example, leaves roll up into cone shapes that reduce drag compared with rigid objects of similar surface area. Less understood is how a leaf attached to a flexible leaf stalk will roll up stably in an unsteady flow. Previous mathematical and physical models have only considered the case of a flexible sheet attached to a rigid tether in steady flow. In this paper, the dynamics of the flow around the leaf of the wild ginge

Cavity Ringdown Spectroscopy of the Hydroxy-Methyl-Peroxy Radical

We report vibrational and electronic spectra of the hydroxy-methyl-peroxy radical (HOCH_2OO^• or HMP), which was formed as the primary product of the reaction of the hydroperoxy radical, HO_2^•, and formaldehyde, HCHO. The ν_1 vibrational (OH stretch) spectrum and the à ← X electronic spectrum of HMP were detected by infrared cavity ringdown spectroscopy (IR-CRDS), and assignments were verified with density functional calculations. The HMP radical was generated in reactions of HCHO with HO_2^•. Free radical reactions were initiated by pulsed laser photolysis (PLP) of Cl_2 in the presence of HCHO and O_2 in a flow reactor at 300–330 Torr and 295 K. IR-CRDS spectra were measured in mid-IR and near-IR regions over the ranges 3525–3700 cm^(–1) (ν_1) and 7250–7800 cm^(–1) (à ← X) respectively, at a delay time 100 μs after photolysis. The ν_1 spectrum had an origin at 3622 cm^(–1) and exhibited partially resolved P- and R-branch contours and a small Q-branch. At these short delay times, spectral interference from HOOH and HCOOH was minimal and could be subtracted. From B3LYP/6-31+G(d,p) calculations, we found that the anharmonic vibrational frequency and band contour predicted for the lowest energy conformer, HMP-A, were in good agreement with the observed spectrum. In the near-IR, we observed four well spaced vibronic bands, each with partially resolved rotational contours. We assigned the apparent origin of the à ← X electronic spectrum of HMP at 7389 cm^(–1) and two bands to the blue to a progression in ν15′, the lowest torsional mode of the à state (ν_(15′) = 171 cm^(–1)). The band furthest to the red was assigned as a hot band in ν^(15″), leading to a ground state torsional frequency of (ν^(15″) = 122 cm^(–1)). We simulated the spectrum using second order vibrational perturbation theory (VPT2) with B3LYP/6-31+G(d,p) calculations at the minimum energy geometries of the HMP-A conformer on the X and à states. The predictions of the electronic origin frequency, torsional frequencies, anharmonicities, and rotational band contours matched the observed spectrum. We investigated the torsional modes more explicitly by computing potential energy surfaces of HMP as a function of the two dihedral angles τ_(HOCO) and τ_(OOCO). Wave functions and energy levels were calculated on the basis of this potential surface; these results were used to calculate the Franck–Condon factors, which reproduced the vibronic band intensities in the observed electronic spectrum. The transitions that we observed all involved states with wave functions localized on the minimum energy conformer, HMP-A. Our calculations indicated that the observed near-IR spectrum was that of the lowest energy X state conformer HMP-A, but that this conformer is not the lowest energy conformer in the à state, which remains unobserved. We estimated that the energy of this lowest conformer (HMP-B) of the à state is E_0 (Ã, HMP-B) ≈ 7200 cm^(–1), on the basis of the energy difference E_0(HMP-B) – E_0(HMP-A) on the à state computed at the B3LYP/6-31+G(d,p) level

Impact of sex on response to neoadjuvant chemotherapy in patients with bladder cancer

© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/.Objective: To assess the effect of patient's sex on response to neoadjuvant chemotherapy (NAC) in patients with clinically nonmetastatic muscle-invasive bladder cancer (MIBC). Methods: Complete pathologic response, defined as ypT0N0 at radical cystectomy, and downstaging were evaluated using sex-adjusted univariable and multivariable logistic regression modeling. We used interaction terms to account for age of menopause and smoking status. The association of sex with overall survival and cancer-specific survival was evaluated using Cox regression analyses. Results: A total of 1,031 patients were included in the analysis, 227 (22%) of whom were female. Female patients had a higher rate of extravesical disease extension (P = 0.01). After the administration of NAC, ypT stage was equally distributed between sexes (P = 0.39). On multivariable logistic regression analyses, there was no difference between the sexes or age of menopause with regards to ypT0N0 rates or downstaging (all P > 0.5). On Cox regression analyses, sex was associated with neither overall survival (hazard ratio 1.04, 95% confidence interval 0.75–1.45, P = 0.81) nor cancer-specific survival (hazard ratio 1.06, 95% confidence interval 0.71–1.58, P = 0.77). Conclusion: Our study generates the hypothesis that NAC equalizes the preoperative disparity in pathologic stage between males and females suggesting a possible differential response between sexes. This might be the explanation underlying the comparable survival outcomes between sexes despite females presenting with more advanced tumor stage.Peer reviewedFinal Accepted Versio

Cholangiocarcinoma 2020: the next horizon in mechanisms and management

[EN] Cholangiocarcinoma (CCA) includes a cluster of highly heterogeneous biliary malignant tumours that can arise at any point of the biliary tree. Their incidence is increasing globally, currently accounting for ~15% of all primary liver cancers and ~3% of gastrointestinal malignancies. The silent presentation of these tumours combined with their highly aggressive nature and refractoriness to chemotherapy contribute to their alarming mortality, representing ~2% of all cancer-related deaths worldwide yearly. The current diagnosis of CCA by non- invasive approaches is not accurate enough, and histological confirmation is necessary. Furthermore, the high heterogeneity of CCAs at the genomic, epigenetic and molecular levels severely compromises the efficacy of the available therapies. In the past decade, increasing efforts have been made to understand the complexity of these tumours and to develop new diagnostic tools and therapies that might help to improve patient outcomes. In this expert Consensus Statement, which is endorsed by the European Network for the Study of Cholangiocarcinoma, we aim to summarize and critically discuss the latest advances in CCA, mostly focusing on classification, cells of origin, genetic and epigenetic abnormalities, molecular alterations, biomarker discovery and treatments. Furthermore, the horizon of CCA for the next decade from 2020 onwards is highlightedJ.M.B. received EASL Registry Awards 2016 and 2019 (European CCA Registry, ENS-CCA). J.M.B. and M.J.P. were supported by: the Spanish Ministry of Economy and Competitiveness (J.M.B.: FIS PI12/00380, FIS PI15/01132, FIS PI18/01075 and Miguel Servet Programme CON14/00129; M.J.P.: FIS PI14/00399, FIS PI17/00022 and Ramon y Cajal Programme RYC-2015-17755, co-financed by “Fondo Europeo de Desarrollo Regional” (FEDER)); ISCIII CIBERehd; “Diputación Foral de Gipuzkoa” (J.M.B: DFG15/010, DFG16/004), and BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15/CA/016/BD); the Department of Health of the Basque Country (M.J.P.: 2015111100; J.M.B.: 2017111010), and “Fundación Científica de la Asociación Española Contra el Cancer” (AECC Scientific Foundation) (J.M.B.). J.M.B. and J.W.V. were supported by the European Commission Horizon 2020 programme (ESCALON project 825510). The laboratory of J.B.A. is supported by competitive grants from the Danish Medical Research Council, the Danish Cancer Society, and the Novo Nordisk and A.P. Møller Foundations. J.J.G.M. and R.I.R.M. were supported by the Carlos III Institute of Health, Spain (PI16/00598 and PI18/00428) and were co-financed by the European Regional Development Fund. J.M.B. and J.J.G.M. were supported by the Ministry of Science and Innovation, Spain (SAF2016-75197-R), and the “Asociación Española Contra el Cancer”, Spain (AECC-2017). R.I.R.M. was supported by the “Centro Internacional sobre el Envejecimiento”, Spain (OLD-HEPAMARKER, 0348-CIE-6-E). A.L. received funding from the Christie Charity. M.M. was supported by the Università Politecnica delle Marche, Ancona, Italy (040020_R.SCIENT.A_2018_MARZIONI_M_STRATEGICO_2017). M.S. was supported by the Yale Liver Center Clinical and Translational Core and the Cellular and Molecular Core (DK034989 Silvio O. Conte Digestive Diseases Research Center). C.C. is supported by grants from INSERM, Université de Rennes, INCa, and ITMO Cancer AVIESAN dans le cadre du Plan Cancer (Non-coding RNA in Cancerology: Fundamental to Translational), Ligue Contre le Cancer and Région Bretagne. J.Bruix was supported by grants from Instituto de Salud Carlos III (PI18/00763), AECC (PI044031) and WCR (AICR) 16-0026. A.F. was supported by grants from ISCIII (PI13/01229 and PI18/00542). CIBERehd is funded by the Instituto de Salud Carlos III. V.C., D.M., J. Bridgewater and P.I. are members of the European Reference Network - Hepatological Diseases (ERN RARE-LIVER). J.M.B. is a collaborator of the ERN RARE-LIVER

T Regulatory Cells Control Susceptibility to Invasive Pneumococcal Pneumonia in Mice

Streptococcus pneumoniae is an important human pathogen responsible for a spectrum of diseases including pneumonia. Immunological and pro-inflammatory processes induced in the lung during pneumococcal infection are well documented, but little is known about the role played by immunoregulatory cells and cytokines in the control of such responses. We demonstrate considerable differences in the immunomodulatory cytokine transforming growth factor (TGF)-β between the pneumococcal pneumonia resistant BALB/c and susceptible CBA/Ca mouse strains. Immunohistochemistry and flow cytometry reveal higher levels of TGF-β protein in BALB/c lungs during pneumococcal pneumonia that correlates with a rapid rise in lung Foxp3+Helios+ T regulatory cells. These cells have protective functions during pneumococcal pneumonia, because blocking their induction with an inhibitor of TGF-β impairs BALB/c resistance to infection and aids bacterial dissemination from lungs. Conversely, adoptive transfer of T regulatory cells to CBA/Ca mice, prior to infection, prolongs survival and decreases bacterial dissemination from lungs to blood. Importantly, strong T regulatory cell responses also correlate with disease-resistance in outbred MF1 mice, confirming the importance of immunoregulatory cells in controlling protective responses to the pneumococcus. This study provides exciting new evidence for the importance of immunomodulation during pulmonary pneumococcal infection and suggests that TGF-β signalling is a potential target for immunotherapy or drug design

Structural and Functional Insights into Endoglin Ligand Recognition and Binding

Endoglin, a type I membrane glycoprotein expressed as a disulfide-linked homodimer on human vascular endothelial cells, is a component of the transforming growth factor (TGF)-β receptor complex and is implicated in a dominant vascular dysplasia known as hereditary hemorrhagic telangiectasia as well as in preeclampsia. It interacts with the type I TGF-β signaling receptor activin receptor-like kinase (ALK)1 and modulates cellular responses to Bone Morphogenetic Protein (BMP)-9 and BMP-10. Structurally, besides carrying a zona pellucida (ZP) domain, endoglin contains at its N-terminal extracellular region a domain of unknown function and without homology to any other known protein, therefore called the orphan domain (OD). In this study, we have determined the recognition and binding ability of full length ALK1, endoglin and constructs encompassing the OD to BMP-9 using combined methods, consisting of surface plasmon resonance and cellular assays. ALK1 and endoglin ectodomains bind, independently of their glycosylation state and without cooperativity, to different sites of BMP-9. The OD comprising residues 22 to 337 was identified among the present constructs as the minimal active endoglin domain needed for partner recognition. These studies also pinpointed to Cys350 as being responsible for the dimerization of endoglin. In contrast to the complete endoglin ectodomain, the OD is a monomer and its small angle X-ray scattering characterization revealed a compact conformation in solution into which a de novo model was fitted

MicroRNA Expression Variability in Human Cervical Tissues

MicroRNAs (miRNAs) are short (∼22 nt) non-coding regulatory RNAs that control gene expression at the post-transcriptional level. Deregulation of miRNA expression has been discovered in a wide variety of tumours and it is now clear that they contribute to cancer development and progression. Cervical cancer is one of the most common cancers in women worldwide and there is a strong need for a non-invasive, fast and efficient method to diagnose the disease. We investigated miRNA expression profiles in cervical cancer using a microarray platform containing probes for mature miRNAs. We have evaluated miRNA expression profiles of a heterogeneous set of cervical tissues from 25 different patients. This set included 19 normal cervical tissues, 4 squamous cell carcinoma, 5 high-grade squamous intraepithelial lesion (HSIL) and 9 low-grade squamous intraepithelial lesion (LSIL) samples. We observed high variability in miRNA expression especially among normal cervical samples, which prevented us from obtaining a unique miRNA expression signature for this tumour type. However, deregulated miRNAs were identified in malignant and pre-malignant cervical tissues after tackling the high expression variability observed. We were also able to identify putative target genes of relevant candidate miRNAs. Our results show that miRNA expression shows natural variability among human samples, which complicates miRNA data profiling analysis. However, such expression noise can be filtered and does not prevent the identification of deregulated miRNAs that play a role in the malignant transformation of cervical squamous cells. Deregulated miRNAs highlight new candidate gene targets allowing for a better understanding of the molecular mechanism underlying the development of this tumour type