Direct measurement of molecular stiffness and damping in confined water layers

We present {\em direct} and {\em linear} measurements of the normal stiffness and damping of a confined, few molecule thick water layer. The measurements were obtained by use of a small amplitude (0.36 $\textrm{\AA}$), off-resonance Atomic Force Microscopy (AFM) technique. We measured stiffness and damping oscillations revealing up to 7 layers separated by 2.56 $\pm$ 0.20 $\textrm{\AA}$. Relaxation times could also be calculated and were found to indicate a significant slow-down of the dynamics of the system as the confining separation was reduced. We found that the dynamics of the system is determined not only by the interfacial pressure, but more significantly by solvation effects which depend on the exact separation of tip and surface. Thus ` solidification\rq seems to not be merely a result of pressure and confinement, but depends strongly on how commensurate the confining cavity is with the molecule size. We were able to model the results by starting from the simple assumption that the relaxation time depends linearly on the film stiffness.Comment: 7 pages, 6 figures, will be submitted to PR

Popular critiques of consultancy and a politics of management learning?

In this short article, I argue that popular business discourse on the role of management consultancy in the promotion and translation of management ideas is often critical, informed by more or less implicit ethical and political concerns with employee security, equity, openness and the transparency and legitimacy of responsibility. These concerns are, in part, ‘sayable’ because their object is seen as a scapegoat for management. Nevertheless, combined with the popular form of their expression, they can support and legitimize critical studies of management learning, a discipline which otherwise has become overly concerned with processual and situational phenomena at the expense of broader political dynamics and of the content and consequences of management and management knowledg

Two-hit model of brain damage in the very preterm newborn: small for gestational age and postnatal systemic inflammation

Background: We sought to disentangle the contributions of perinatal systemic inflammation and small for gestational age (SGA) to the occurrence of low Bayley Mental Development Indices (MDIs) at age 2 years. Method We measured the concentration of 25 inflammation-related proteins in blood obtained during the first 2 postnatal weeks from 805 infants who were born before the 28th week of gestation and who had MDI measurements at age 2 years and were able to walk independently. Results: SGA newborns who did not have systemic inflammation (a concentration of an inflammation-related protein in the top quartile for gestational age on 2 days a week apart) were at greater risk of an MDI < 55, but not 55–69, than their peers who had neither SGA nor systemic inflammation. SGA infants who had elevated blood concentrations of IL-1beta, TNF-alpha, or IL-8 during the first two postnatal weeks were at even higher risk of an MDI < 55 than their SGA peers without systemic inflammation and of their non-SGA peers with systemic inflammation. Conclusion: SGA appears to place very preterm newborns at increased risk of a very low MDI. Systemic inflammation adds considerably to the increased risk

Ultrashort-pulse laser with an intracavity phase shaping element

A novel ultrashort-pulse laser cavity configuration that incorporates an intracavity deformable mirror as a phase control element is reported. A user-defined spectral phase relation of 0.7 radians relative shift could be produced at around 1035 nm. Phase shaping as well as pulse duration optimization was achieved via a computer-controlled feedback loop

Health system interventions to integrate genetic testing in routine oncology services: A systematic review

Background Integration of genetic testing into routine oncology care could improve access to testing. This systematic review investigated interventions and the tailored implementation strategies aimed at increasing access to genetic counselling and testing and identifying hereditary cancer in oncology. Methods The search strategy results were reported using the PRISMA statement and four electronic databases were searched. Eligible studies included routine genetic testing for breast and ovarian cancer or uptake after universal tumour screening for colorectal or endometrial cancer. The titles and abstracts were reviewed and the full text articles screened for eligibility. Data extraction was preformed using a designed template and study appraisal was assessed using an adapted Newcastle Ottawa Scale. Extracted data were mapped to Proctor’s et al outcomes and the Consolidated Framework for Implementation Research and qualitatively synthesised. Results Twenty-seven studies, published up to May 2020, met the inclusion criteria. Twenty-five studies ranged from poor (72%), fair to good (28%) quality. Most interventions identified were complex (multiple components) such as; patient or health professional education, interdisciplinary practice and a documentation or system change. Forty-eight percent of studies with complex interventions demonstrated on average a 35% increase in access to genetic counselling and a 15% increase in testing completion. Mapping of study outcomes showed that 70% and 32% of the studies aligned with either the service and client or the implementation level outcome and 96% to the process or inner setting domains of the Consolidated Framework for Implementation Research. Conclusion Existing evidence suggests that complex interventions have a potentially positive effect towards genetic counselling and testing completion rates in oncology services. Studies of sound methodological quality that explore a greater breadth of pre and post implementation outcomes and informed by theory are needed. Such research could inform future service delivery models for the integration of genetics into oncology services

Recent key developments in nanoscale reliability and failure analysis techniques for advanced nanoelectronics devices

Last decade has witnessed an aggressive scaling of CMOS technology nodes pushing it all the way down to sub-10nm and this scaling trend looks positive for the next two-three nodes as well down to 5nm. This push for scaling of the technology node has created a need for using material characterization techniques with (sub)nanometer probe resolution to characterize these advanced nanoelectronic devices - to observe and understand the underlying thermodynamics and kinetics of the physical phenomenon at the nanometer scale in real-time. Among these advanced characterization techniques, transmission election microscopy (TEM) and scanning probe microscopy (SPM), as well as the techniques derived from these, have become critical and instrumental to failure analysis and for evaluation of key design metrics for reliability studies. In this work, we present the different case studies using these two techniques which we have employed for studying both advanced logic and memory devices. High resolution TEM (HRTEM) has been used for both RRAM and gate oxide reliability studies due to its multiple compositional characterization capabilities with sub-nm resolution. TEM can routinely achieve a resolution around 0.1nm and thus can provide tremendous information related to structure (Diffraction Pattern) and composition (Electron Energy Loss Spectroscopy). Ex-situ TEM techniques (supported by Focused Ion Beam (FIB)) have allowed us to perform diverse electrical and thermal testing on devices. We have found concrete evidence of FinFET device degradation recently [1]. We have also employed in-situ TEM techniques (facilitated by scanning tunneling microscopy (STM) and the thermal holder) to observe the degradation behavior of metal-dielectric stacks in real-time [2]. The in-situ TEM technique has provided insight into the direct and solid time sequential evolution of failure behavior in RRAM devices. Additionally, 3D tomography characterization of the defect and failure spot has been acquired by tilting the sample and collecting the sequential images at different angles [3]. This technique of 3D tomography is a very powerful one for defect reorganization and for root cause analysis of failure mechanism. Conductive atomic force microscopy (CAFM) and STM are two techniques, belonging to a large pool of available SPM tools, which we have used for breakdown studies in ultra-thin HfO2 and other high-κ dielectrics as well as multi-layered fluorinated graphene (FG) stacks. With a resolution, down to ~10nm and ~0.1nm for CAFM and STM respectively under ultra-high vacuum (UHV) conditions, we have applied these tools to measure electrical properties (I-V and dI/dV) at grain and grain boundary spots in ultra-thin polycrystalline HfO2 dielectrics [4] as well as to understand the breakdown mechanism in FG stacks [5]. We have also explored the local spectroscopy capabilities (of both STM and CAFM) for the measurement of random telegraph noise (RTN) in blanket HfO2 films. Using bias dependent RTN measurements, it has been possible to quantify the position of the defect in the probed location of the dielectric. Interestingly, these dielectric breakdowns and RTN measurements at the nanoscale have also provided experimental evidence of defect clustering in polycrystalline dielectrics and possible existence of the metastable nature of oxygen vacancy (VO) defect in HfO2 respectively [6]. CAFM has also been explored to study the role of VO in HfO2 based RRAM stacks for ultra-low power memory applications where the signature of sub-quantum conductance based resistive switching has been experimentally observed [7]. We strongly believe that these tools and techniques would play an indispensable role in unveiling the underlying physics of the nanoscale physical phenomenon for existing as well as emerging materials and 2D/3D devices. References: [1] S. Mei et al., IEDM (2016). [2] K. L. Pey et al., IRPS (2010). [3] S. Mei et al., Unpublished. [4] K. Shubhakar et al., Micro. Engineering (2013). [5] A. Ranjan et al., IRPS (2017, Accepted). [6] A. Ranjan et al., IRPS (2016

Intramolecular vibronic dynamics in molecular solids: C60

Vibronic coupling in solid C60 has been investigated with a combination of resonant photoemission spectroscopy (RPES) and resonant inelastic x-ray scattering (RIXS). Excitation as a function of energy within the lowest unoccupied molecular orbital resonance yielded strong oscillations in intensity and dispersion in RPES, and a strong inelastic component in RIXS. Reconciling these two observations establishes that vibronic coupling in this core hole excitation leads to predominantly inelastic scattering and localization of the excited vibrations on the molecule on a femtosecond time scale. The coupling extends throughout the widths of the frontier valence bands.

Decomposable representations and Lagrangian submanifolds of moduli spaces associated to surface groups

In this paper, we construct a Lagrangian submanifold of the moduli space associated to the fundamental group of a punctured Riemann surface (the space of representations of this fundamental group into a compact connected Lie group). This Lagrangian submanifold is obtained as the fixed-point set of an anti-symplectic involution defined on the moduli space. The notion of decomposable representation provides a geometric interpretation of this Lagrangian submanifold

Application of a Catalytic Asymmetric Povarov Reaction using Chiral Ureas to the Synthesis of a Tetrahydroquinoline Library

A 2328-membered library of 2,3,4-trisubstituted tetrahydroquinolines was produced using a combination of solution- and solid-phase synthesis techniques. A tetrahydroquinoline (THQ) scaffold was prepared via an asymmetric Povarov reaction using cooperative catalysis to generate three contiguous stereogenic centers. A matrix of 4 stereoisomers of the THQ scaffold was prepared to enable the development of stereo/structure-activity relationships (SSAR) upon biological testing. A sparse matrix design strategy was employed to select library members to be synthesized with the goal of generating a diverse collection of tetrahydroquinolines with physicochemical properties suitable for downstream discovery.Chemistry and Chemical Biolog

All-optical switching and strong coupling using tunable whispering-gallery-mode microresonators

We review our recent work on tunable, ultrahigh quality factor whispering-gallery-mode bottle microresonators and highlight their applications in nonlinear optics and in quantum optics experiments. Our resonators combine ultra-high quality factors of up to Q = 3.6 \times 10^8, a small mode volume, and near-lossless fiber coupling, with a simple and customizable mode structure enabling full tunability. We study, theoretically and experimentally, nonlinear all-optical switching via the Kerr effect when the resonator is operated in an add-drop configuration. This allows us to optically route a single-wavelength cw optical signal between two fiber ports with high efficiency. Finally, we report on progress towards strong coupling of single rubidium atoms to an ultra-high Q mode of an actively stabilized bottle microresonator.Comment: 20 pages, 24 figures. Accepted for publication in Applied Physics B. Changes according to referee suggestions: minor corrections to some figures and captions, clarification of some points in the text, added references, added new paragraph with results on atom-resonator interactio