191 research outputs found
The nature of multiple boron-nitrogen bonds studied using electron localization function (ELF), electron density (AIM), and natural bond orbital (NBO) methods
Local nature of the boron-nitrogen (BN) bonding with different formal multiplicities (BâĄN, B=N, B-N) have been investigated for 25 experimentally established organoboron molecules in both real and the Hilbert space, using topological analysis of electron localization function (ELF), electron density (AIM), and natural bond orbital (NBO) method. Each BN bond has been represented (ELF) by the bonding disynaptic attractor V(B,N), with the basin electron population between 5.72e and 1.83e, confirming possible existence of all the three bond types. A covalent character of bonding can be associated with the dative mechanism due to the V(B,N) bonding basin formed mainly (91â96%) by the N electron density. Similarly, the NBO method shows 2-center natural orbitals, consisting largely of the hybrids from the N atom. The AIM analysis yields the features typical for shared (H(3,â1)(r)ââ0) interactions. The delocalization indices, describing electron exchanges between B and N quantum atoms, are smaller than 1.5, even for formally very short triple BâĄN bonds
A Multi Expert Decision Support Tool for the Evaluation of Advanced Wastewater Treatment Trains: A Novel Approach to Improve Urban Sustainability
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Wastewater Treatment (WWT) for water reuse applications has been accepted as a
strategic solution in improving water supplies across the globe; however, there are still
various challenges that should be overcome. Selection of practical solutions is then
required whilst considering technical, environmental, socio-cultural, and financial factors.
In this study, a multi expert decision support tool that considers a variety of evaluation
criteria is proposed to provide a ranking system for competing advanced WWT
technologies in terms of their performance. Two scenarios of water reuse in the contexts
of Brazil and Greece are defined, and evaluation is undertaken based on opinions of
water reuse experts. The results prove that the tool would successfully facilitate rigorous
and methodical analysis in evaluation of WWT technologies for water reuse applications
with potential for use under various sets of evaluation criteria, WWT technologies and
contexts
Flight Servicing of Robotic Refueling Mission 3
The Robotic Refueling Mission 3 (RRM3) payload launched aboard a SpaceX rocket en route to the International Space Station on December 5th, 2018. The Goddard Space Flight Center designed payload carried approximately 50 liters of liquid methane onboard, with a mission to demonstrate long term storage and transfer of the cryogenic fluid in microgravity. Kennedy Space Center (KSC) was tasked to design, fabricate, test, and operate a system equipped to fill an RRM3 dewar with liquid methane prior to launch. Though KSC has a rich history of fueling rockets and payloads, no such operations had previously been accomplished using liquid methane. As such, all of the hardware and processes had to be developed from scratch. The completed ground system design, along with the verification and validation testing will be outlined in this paper. Several challenges that were met and overcome during procurement of the high purity methane are described. In addition, budget restrictions prohibited fueling operations from occurring in traditional processing facilities. The unique and creative solutions which were required to maintain payload cleanliness during cryogenic servicing are also detailed
Volumetric 18FâFDGâPET parameters as predictors of locoregional failure in lowârisk HPVârelated oropharyngeal cancer after definitive chemoradiation therapy
BackgroundWe sought to investigate the prognostic value of volumetric positron emission tomography (PET) parameters in patients with human papillomavirus (HPV)ârelated oropharyngeal squamous cell carcinoma (OPSCC) and a â€10 packâyear smoking history treated with chemoradiation.MethodsA total of 142 patients were included. Maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of the primary tumor, involved regional lymph nodes, and total lesion were calculated. Cox proportional hazard modeling was used to evaluate associations of clinical and PET parameters with locoregional failureâfree survival (LRFFS), distant metastasisâfree survival (DMFS), and overall survival (OS).ResultsOn univariate analysis, volumetric PET parameters were significantly associated with all endpoints, and 8th edition American Joint Committee on Cancer/Union Internationale Contre le Cancer staging was significantly associated with DMFS and OS. On multivariate analysis, total lesion TLG was significantly associated with LRFFS, while staging was most significantly prognostic for DMFS and OS.ConclusionVolumetric PET parameters are uniquely prognostic of LRFFS in lowârisk HPVârelated OPSCC and may be useful for directing deâintensification strategies.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147800/1/hed25505_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147800/2/hed25505.pd
HIPK2 and extrachromosomal histone H2B are separately recruited by Aurora-B for cytokinesis
Cytokinesis, the final phase of cell division, is necessary to form two distinct daughter cells with correct distribution of genomic and cytoplasmic materials. Its failure provokes genetically unstable states, such as tetraploidization and polyploidization, which can contribute to tumorigenesis. Aurora-B kinase controls multiple cytokinetic events, from chromosome condensation to abscission when the midbody is severed. We have previously shown that HIPK2, a kinase involved in DNA damage response and development, localizes at the midbody and contributes to abscission by phosphorylating extrachromosomal histone H2B at Ser14. Of relevance, HIPK2-defective cells do not phosphorylate H2B and do not successfully complete cytokinesis leading to accumulation of binucleated cells, chromosomal instability, and increased tumorigenicity. However, how HIPK2 and H2B are recruited to the midbody during cytokinesis is still unknown. Here, we show that regardless of their direct (H2B) and indirect (HIPK2) binding of chromosomal DNA, both H2B and HIPK2 localize at the midbody independently of nucleic acids. Instead, by using mitotic kinase-specific inhibitors in a spatio-temporal regulated manner, we found that Aurora-B kinase activity is required to recruit both HIPK2 and H2B to the midbody. Molecular characterization showed that Aurora-B directly binds and phosphorylates H2B at Ser32 while indirectly recruits HIPK2 through the central spindle components MgcRacGAP and PRC1. Thus, among different cytokinetic functions, Aurora-B separately recruits HIPK2 and H2B to the midbody and these activities contribute to faithful cytokinesis
Corresponding States of Structural Glass Formers
The variation with respect to temperature T of transport properties of 58
fragile structural glass forming liquids (68 data sets in total) are analyzed
and shown to exhibit a remarkable degree of universality. In particular,
super-Arrhenius behaviors of all super-cooled liquids appear to collapse to one
parabola for which there is no singular behavior at any finite temperature.
This behavior is bounded by an onset temperature To above which liquid
transport has a much weaker temperature dependence. A similar collapse is also
demonstrated, over the smaller available range, for existing numerical
simulation data.Comment: 6 pages, 2 figures. Updated References, Table Values, Submitted for
Publicatio
Impact of American Joint Committee on Cancer Eighth Edition clinical stage and smoking history on oncologic outcomes in human papillomavirusâassociated oropharyngeal squamous cell carcinoma
BackgroundThe purpose of this study was to evaluate the AJCC eighth edition clinical staging system for human papillomavirus (HPV)âassociated oropharyngeal squamous cell carcinoma and to further understand how clinical stage and smoking history affect oncologic outcomes. The purpose of this study was to present the understanding of how clinical stage and smoking history affect oncologic outcomes in human papillomavirus (HPV)âassociated oropharyngeal squamous cell carcinoma (SCC) is critical for selecting patients for treatment deintensification.MethodsKaplanâMeier and Cox regression were used to evaluate overall survival (OS), locoregional recurrenceâfree survival (LRFS), and distant recurrenceâfree survival (DRFS). Concordance statistics (Câindices) were used to compare discriminating ability.ResultsThe OS and DRFS but not LRFS were significantly distributed using the American Joint Committee on Cancer (AJCC) seventh and eighth editions criteria. The Câindices for OS, LRFS, and DRFS were 0.57, 0.54, and 0.60, respectively, using the AJCC seventh edition, and 0.63, 0.53, and 0.65, respectively, using the AJCC eighth edition. On multivariate analysis, 1â+âpackâyear smoking history correlated with OS (hazard ratio [HR] 1.96; 95% confidence interval [CI] 1.2â3.1; Pâ<â.01) but not LRFS or DRFS.ConclusionThese results support implementation of the AJCC eighth edition for HPVâassociated oropharyngeal SCC. Clinical stage may be more important than smoking history in selection for deintensification.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148352/1/hed25336_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148352/2/hed25336.pd
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Mutational profiles of persistent/recurrent laryngeal squamous cell carcinoma
BackgroundWe sought to describe targeted DNA sequencing data of persistent/recurrent laryngeal squamous cell carcinoma (LSCC) and to compare geneâspecific alteration frequencies with that of primary, untreated LSCC specimens from The Cancer Genome Atlas (TCGA).MethodsThe tumors of 21 patients with persistent/recurrent LSCC were subjected to targeted DNA sequencing using the Ion AmpliSeq Comprehensive Cancer Panel. Geneâspecific alteration frequencies were compared (ChiâSquare test) to primary, untreated LSCC sequencing data from TCGA using the cBioPortal platform.ResultsPersistent/recurrent LSCC was characterized by a high rate of inactivating alterations in TP53 (38.1%) and CDKN2A (33%), amplification events of CCND1 (19.1%), and ERBB2 (14.3%), and NOTCH1 (19.1%) mutations. Comparison of primary vs persistent/recurrent LSCC revealed significant differences in alteration frequencies of eight critical genes: BAP1, CDKN2A, DCUN1D1, MSH2, MTOR, PIK3CA, TET2, and TP53.ConclusionsOur results provide preliminary support for a distinct mutational profile of persistent/recurrent LSCC that requires validation in larger cohorts.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147873/1/hed25444.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147873/2/hed25444_am.pd
Avaliação de tecnologias avançadas para o reĂșso de ĂĄgua em indĂșstria metal-mecĂąnica
Vesicular glutamate release from central axons contributes to myelin damage
Neuronal activity can lead to vesicular release of glutamate. Here the authors demonstrate that vesicular release of glutamate occurs in axons during ischemic conditions, and that an allosteric modulator of GluN2C/D is protective in models of ischemic injury
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