1,361 research outputs found
On the interactions of lipids and proteins in the red blood cell membrane
The effects of temperature and of the action of a purified phospholipase C enzyme preparation on human red blood cell membranes has been investigated by chemical analyses, circular dichroism, and proton magnetic resonance measurements. The results indicate that a substantial fraction of the phospholipids and the proteins of the membranes can change structure independently of one another, suggesting a mosaic pattern for the organization of the lipids and proteins in membranes
Theory for Nonlinear Spectroscopy of Vibrational Polaritons
Molecular polaritons have gained considerable attention due to their
potential to control nanoscale molecular processes by harnessing
electromagnetic coherence. Although recent experiments with liquid-phase
vibrational polaritons have shown great promise for exploiting these effects,
significant challenges remain in interpreting their spectroscopic signatures.
In this letter, we develop a quantum-mechanical theory of pump-probe
spectroscopy for this class of polaritons based on the quantum Langevin
equations and the input-output theory. Comparison with recent experimental data
shows good agreement upon consideration of the various vibrational
anharmonicities that modulate the signals. Finally, a simple and intuitive
interpretation of the data based on an effective mode-coupling theory is
provided. Our work provides a solid theoretical framework to elucidate
nonlinear optical properties of molecular polaritons as well as to analyze
further multidimensional spectroscopy experiments on these systems
Magnetic flux flow and superconductor stabilization Quarterly report, 1 Jan. - 31 Mar. 1968
Magnetic flux flow and stability of superconducting niobium titanium strip
Reliable and accurate diagnostics from highly multiplexed sequencing assays
Scalable, inexpensive, and secure testing for SARS-CoV-2 infection is crucial for control of the novel coronavirus pandemic. Recently developed highly multiplexed sequencing assays (HMSAs) that rely on high-throughput sequencing can, in principle, meet these demands, and present promising alternatives to currently used RT-qPCR-based tests. However, reliable analysis, interpretation, and clinical use of HMSAs requires overcoming several computational, statistical and engineering challenges. Using recently acquired experimental data, we present and validate a computational workflow based on kallisto and bustools, that utilizes robust statistical methods and fast, memory efficient algorithms, to quickly, accurately and reliably process high-throughput sequencing data. We show that our workflow is effective at processing data from all recently proposed SARS-CoV-2 sequencing based diagnostic tests, and is generally applicable to any diagnostic HMSA
Revealing Hidden Vibration Polariton Interactions by 2D IR Spectroscopy
We report the first experimental two-dimensional infrared (2D IR) spectra of
novel molecular photonic excitations - vibrational-polaritons. The application
of advanced 2D IR spectroscopy onto novel vibrational-polariton challenges and
advances our understanding in both fields. From spectroscopy aspect, 2D IR
spectra of polaritons differ drastically from free uncoupled molecules; from
vibrational-polariton aspects, 2D IR uniquely resolves hybrid light-matter
polariton excitations and unexpected dark states in a state-selective manner
and revealed hidden interactions between them. Moreover, 2D IR signals
highlight the role of vibrational anharmonicities in generating non-linear
signals. To further advance our knowledge on 2D IR of vibrational polaritons,
we develop a new quantum-mechanical model incorporating the effects of both
nuclear and electrical anharmonicities on vibrational-polaritons and their 2D
IR signals. This work reveals polariton physics that is difficult or impossible
to probe with traditional linear spectroscopy and lays the foundation for
investigating new non-linear optics and chemistry of molecular
vibrational-polaritons
Towards energetically viable asymmetric deprotonations : selectivity at more elevated temperatures with C2-symmetric magnesium bisamides
A novel chiral magnesium bisamide has enabled the development of effective asymmetric deprotonation protocols at substantially more elevated temperatures. This new, structurally simple, C2-symmetric magnesium complex displays excellent levels of asymmetric efficiency and energy reduction in the synthesis of enantioenriched enol silane
Two-dimensional Navier--Stokes simulation of deformation and break up of liquid patches
The large deformations and break up of circular 2D liquid patches in a high
Reynolds number (Re=1000) gas flow are investigated numerically. The 2D, plane
flow Navier--Stokes equations are directly solved with explicit tracking of the
interface between the two phases and a new algorithm for surface tension. The
numerical method is able to pursue the simulation beyond the breaking or
coalescence of droplets. The simulations are able to unveil the intriguing
details of the non-linear interplay between the deforming droplets and the
vortical structures in the droplet's wake.Comment: 13 pages including 4 postscript figures; Revised version as
resubmitted to PRL. Title has change
The prognostic significance of tumour-stroma ratio in oestrogen receptor-positive breast cancer
BACKGROUND:
A high percentage of stroma predicts poor survival in triple-negative breast cancers but is diminished in studies of unselected cases. We determined the prognostic significance of tumour-stroma ratio (TSR) in oestrogen receptor (ER)-positive male and female breast carcinomas.
METHODS:
TSR was measured in haematoxylin and eosin-stained tissue sections (118 female and 62 male). Relationship of TSR (cutoff 49%) to overall survival (OS) and relapse-free survival (RFS) was analysed.
RESULTS:
Tumours with ≥49% stroma were associated with better survival in female (OS P=0.008, HR=0.2-0.7; RFS P=0.006, HR=0.1-0.6) and male breast cancer (OS P=0.005, HR=0.05-0.6; RFS P=0.01, HR=0.87-5.6), confirmed in multivariate analysis.
CONCLUSIONS:
High stromal content was related to better survival in ER-positive breast cancers across both genders, contrasting data in triple-negative breast cancer and highlighting the importance of considering ER status when interpreting the prognostic value of TSR
Enantioselective Proton Transfer Chemistry: Asymmetric Synthesis with Chiral Lithium Amide Bases
Air entrainment through free-surface cusps
In many industrial processes, such as pouring a liquid or coating a rotating
cylinder, air bubbles are entrapped inside the liquid. We propose a novel
mechanism for this phenomenon, based on the instability of cusp singularities
that generically form on free surfaces. The air being drawn into the narrow
space inside the cusp destroys its stationary shape when the walls of the cusp
come too close. Instead, a sheet emanates from the cusp's tip, through which
air is entrained. Our analytical theory of this instability is confirmed by
experimental observation and quantitative comparison with numerical simulations
of the flow equations
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