Optical sub-diffraction limited focusing for confined heating and lithography

Electronics and nanotechnology is constantly demanding a decrease in size of fabricated nanoscale features. This decrease in size has become much more difficult recently due to the limited resolution of optical systems that are fundamental to many nanofabrication methods. A lot of effort has been made to fabricate devices smaller than the diffraction limit of light. Creating devices that are capable of confining fields by means of interference patterns of propagating wave modes and surface plasmon, has proven successful to confine light into smaller spot sizes. Zone plate diffraction lenses generate spots with dimensions very close to the diffraction limit. We report the fabrication of zone plates to be used in laser direct writing of silicon nanowires. We show experimentally and with numerical models that a silicon substrate subjected to a focused spot is capable of reaching the necessary temperature for the synthesis of silicon nanowires with widths of 60 nm, which is considerably smaller than the diffraction limit of the processing laser. Nanoscale ridge apertures are devices with a great potential to confine light energy. Such apertures have been experimentally proven to create very small lithography features. We believe that these apertures can be further modified in order to achieve a practical smaller confinement in the near field region. In this thesis we discuss several attempts to design and fabricate apertures with sharp edges and implement them in a previously reported parallel lithography setup. In an attempt to use apertures for parallel fabrication of patterns, we developed a system to control the position of the near-field region with respect to a lithography substrate. To do this we use a method of interferometric-spatial- phase-imaging (ISPI). With the implementation of this method we were able to produce an array of 32X32 lines with confined widths as small as 22 nm. Nanoscale ridge apertures were also studied to be used as near field transducers for heat-assisted magnetic recording. They have the capability of transmitting and confining enough energy to increase the temperature of a recording medium without reaching detrimental temperatures themselves. Numerical methods are presented to prove theoretically that a well-designed aperture performs well as a near field transducer. The size of the spot region focused by the aperture could allow us to record data with higher area density than current conventional methods

Optical nanolithography with λ/15 resolution using bowtie aperture array

We report optical parallel nanolithography using bowtie apertures with the help of the interferometric-spatial-phase-imaging (ISPI) technique. The ISPI system can detect and control the distance between the bowtie aperture, and photoresist with a resolution of sub-nanometer level. It overcomes the difficulties brought by the light divergence of bowtie apertures. Parallel nanolithography with feature size of 22 ± 5 nm is achieved. This technique combines high resolution, parallel throughput, and low cost, which is promising for practical applications.United States. Defense Advanced Research Projects Agency (Grant N66001-08-1-2037)National Science Foundation (U.S.) (Grant CMMI-1120577

Sub-diffraction Laser Synthesis of Silicon Nanowires

We demonstrate synthesis of silicon nanowires of tens of nanometers via laser induced chemical vapor deposition. These nanowires with diameters as small as 60 nm are produced by the interference between incident laser radiation and surface scattered radiation within a diffraction limited spot, which causes spatially confined, periodic heating needed for high resolution chemical vapor deposition. By controlling the intensity and polarization direction of the incident radiation, multiple parallel nanowires can be simultaneously synthesized. The nanowires are produced on a dielectric substrate with controlled diameter, length, orientation, and the possibility of in-situ doping, and therefore are ready for device fabrication. Our method offers rapid one-step fabrication of nano-materials and devices unobtainable with previous CVD methods

High precision dynamic alignment and gap control for optical near-field nanolithography

The authors demonstrate the use of interferometric-spatial-phase-imaging (ISPI) to control a gap distance of the order of nanometers for parallel optical near-field nanolithography. In optical near-field nanolithography, the distance between the optical mask and the substrate needs to be controlled within tens of nanometers or less. The ISPI technique creates interference fringes from checkerboard gratings fabricated on the optical mask, which are used to determine the gap distance between the mask and the substrate surfaces. The sensitive of this gapping technique can reach 0.15 nm. With the use of ISPI and a dynamic feedback control system, the authors can precisely align the mask and the substrate and keep variation of the gap distance below 6 nm to realize parallel nanolithography. (C) 2013 American Vacuum Society

Detection of prostate cancer using a voltammetric electronic tongue

[EN] A simple method based on the multivariate analysis of data from urine using an electronic voltammetric tongue is used to detect patients with prostate cancer. A sensitivity of 91% and a specificity of 73% were obtained to distinguish the urine from cancer patients and the urine from non-cancer patients.The authors gratefully acknowledge the Ministerio de Economia y Competitividad and FEDER (project MAT2015-64139-C4-1-R (MINECO/FEDER)), the Generalitat Valenciana (project PROMETEOII/2014/047) and CIBER-BBN (NANOP-ROBE project) for their financial support. A. L. is grateful to the Generalitat Valenciana for her grant (Vali+d ACIF: 2015/115).Pascual, L.; Campos Sánchez, I.; Vivancos, J.; Quintás, G.; Loras Monfort, A.; Martínez-Bisbal, M.; Martínez-Máñez, R.... (2016). Detection of prostate cancer using a voltammetric electronic tongue. Analyst. 141(15):4562-4567. https://doi.org/10.1039/C6AN01044JS456245671411

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Um estudo comparativo de dois serviços de saúde mental: relações entre participação popular e representações sociais relacionadas ao direito à saúde A comparative study of two mental health services: relationships between popular participation and social representations related to the right to health

Este artigo origina-se de uma pesquisa qualitativa que analisou representações sociais relacionadas ao direito à saúde de usuários de dois serviços de saúde mental: um constituído e funcionando com participação de usuários e familiares e outro sem essa participação, visando conhecê-las não apenas vinculadas à consciência do direito à saúde, mas também a fatores associados, como: participação popular, o processo de adoecimento; o atendimento público de saúde, percepção da capacidade de intervenção social, e concepções sobre o Estado. As representações sociais encontradas associadas ao direito à saúde implicam expectativas de que o sistema de saúde e o Estado cumpram funções de acolhimento e amparo. Os usuários do serviço sem participação popular tendem a ser mais conformados e pessimistas. O grupo com participação popular vê o serviço que construiu como possuidor das características negadas pelo sistema oficial e percebe como possível a ação reivindicativa, podendo ser um foco alternativo na formação de novas representações sociais.<br>The present paper originated from a qualitative study that analyzed social representations related to the right to health, expressed by users of two types of mental health services, one with participation by users and families and the other without such participation. The aim was to analyze such representations not only in relation to the awareness of the right to health, but also concerning associated factors, such as: popular participation; illness; public health care; perception of social intervention capacity; and concepts concerning the state. Social representations of the right to health involve expectations that the health system and the state meet their roles of ensuring care and support. Users of the mental health service without user/family participation tended to be more resigned and pessimistic. The group with participation views the service it has built as having characteristics denied by the official system and view advocacy as a possible alternative focus for forming new social representations