Non-Volatile Transistor Memory with a Polypeptide Dielectric.

Organic nonvolatile transistor memory with synthetic polypeptide derivatives as dielectric was fabricated by a solution process. When only poly (γ-benzyl-l-glutamate) (PBLG) was used as dielectric, the device did not show obvious hysteresis in transfer curves. However, PBLG blended with PMMA led to a remarkable increase in memory window up to 20 V. The device performance was observed to remarkably depend on the blend ratio. This study suggests the crystal structure and the molecular alignment significantly affect the electrical performance in transistor-type memory devices, thereby provides an alternative to prepare nonvolatile memory with polymer dielectrics.

Estimating the Memory Order of Electrocorticography Recordings.

OBJECTIVE: This paper presents a data-driven method for estimating the memory order (the average length of the statistical dependence of a given sample on previous samples) of a recorded electrocorticography (ECoG) sequence. METHODS: The proposed inference method is based on the relationship between the loss in predicting the next sample in a time-series and the dependence of this sample on the previous samples. Specifically, the memory order is estimated to be the number of past samples that minimize the least squares error (LSE) in predicting the next sample. To deal with the lack of an analytical model for ECoG recordings, the proposed method combines a collection of different predictors, thereby achieving LSE at least as low as the LSE achieved by each of the different predictors. RESULTS: ECoG recordings from six patients with epilepsy were analyzed, and the empirical cumulative density functions (ECDFs) of the memory orders estimated from these recordings were generated, for rest as well as pre-ictal time intervals. For pre-ictal time intervals, the electrodes corresponding to the seizure-onset-zone were separately analyzed. The estimated ECDFs were different between patients and between different types of blocks. For all the analyzed patients, the estimated memory orders were on the order of tens of milliseconds (up to 100 ms). SIGNIFICANCE: The proposed method facilitates the estimation of the causal associations between ECoG recordings, as these associations strongly depend on the recordings' memory. An improved estimation of causal associations can improve the performance of algorithms that use ECoG recordings to localize the epileptogenic zone. Such algorithms can aid doctors in their pre-surgical planning for the surgery of patients with epilepsy.

Diez años desde la implementación del RIS PACS de la Clínica Alemana de Santiago: impacto de la tomografía computarizada en el uso y disponibilidad de archivo / Ten years since the implementation of Clínica Alemana of Santiago's RIS PACS: the impact of computed tomography in the use and availability of storage

Abstract. RIS PACS systems have become indispensable for managing, distributing and archiving digital images. This study evaluated the impact of Computed Tomography in the Clínica Alemana of Santiago's PACS image service. The PACS database was reviewed using IMPAX BI software, and 2,267,683 studies between 2005 and 2014 were examined. Computed Tomography examinations made up 10.67% of the studies archived in PACS, but its weight in TB is 50.10% of the total. The impact of the studies of Computed Tomography were not properly dimensioned or anticipated, which has impacted on the expected availability for one year online studies. This study has adequately assessed the impact of Computed Tomography in PACS’ storage availability, and how it should be considered when planning the implementation of a PACS.

Resumen. Los sistemas RIS PACS se han vuelto indispensables para el manejo de las imágenes digitales, su distribución y archivo. Esta investigación evaluó el impacto de la tomografía computarizada en el PACS del servicio de imágenes de la Clínica Alemana de Santiago. Se revisó la base de datos del PACS a través de la herramienta de software IMPAX BI, de los 2.267.683 estudios del período 2005-2014. Los exámenes de tomografía computarizada representan el 10,67% de los estudios archivados en el PACS, pero su peso en TB es el 50,10% del total. El impacto de los estudios de tomografía computarizada no se ha dimensionado ni previsto adecuadamente, lo que ha impactado en la disponibilidad esperada para los estudios de un año on line. Este estudio ha permitido valorar adecuadamente el impacto de la tomografía computarizada en la disponibilidad del PACS, y cómo debe ser considerado al planificar la implementación de un PACS.

The first picture archiving and communication system in Lao People's Democratic Republic: Changes in the utilization rate of imaging tests in the first year after implementation.

BACKGROUND: Implementation of the Picture Archiving and Communication System (PACS) is more challenging in developing countries than in developed countries. Given that the first PACS in Lao People's Democratic Republic (PDR) was successfully installed at the Children's Hospital of Lao PDR, we aimed to investigate whether the utilization rate of imaging tests increased after PACS implementation. METHODS: PACS was implemented at the Children's Hospital of Lao PDR in December 2014. We compared the utilization rates of imaging tests including X-ray and ultrasound examinations between the pre-PACS period (from December 2013 to November 2014) and the post-PACS period (from December 2014 to November 2015). The utilization rate was defined as the number of imaging tests divided by the number of patients per month. RESULTS: The average number of total imaging tests was 225.8/month (standard deviation [SD], 37.7) during the 1-year pre-PACS period and was 269.4/month (SD, 38.5) during the 1-year post-PACS period (P=0.0103). The utilization rate of total imaging tests significantly increased after PACS implementation (pre-PACS, 2.47%/month; post-PACS, 4.23%/month; P<0.0001). Increased utilization rates were observed for both X-rays (pre-PACS, 1.65%/month; post-PACS, 2.38%/month; P=0.0004) and ultrasound examinations (pre-PACS, 0.82%/month; post-PACS, 1.85%/month; P=0.0001). CONCLUSIONS: The implementation of PACS at the Children's Hospital of Lao PDR resulted in a significant increase in the utilization rate of imaging tests, suggesting the indirect benefit of improved quality of care. Our findings showed that the benefits of PACS can be realized even in a resource-limited country such as Lao PDR.

Saúde Móvel: novas perspectivas para a oferta de serviços em saúde / Mobile health: new perspectives for healthcare provision / Salud Móvil: nuevas perspectivas para la prestación de servicios de salud

OBJETIVO: revisar e discutir as novas perspectivas para a oferta de serviços em saúde decorrentes do desenvolvimento da saúde móvel e dos dispositivos vestíveis inteligentes. MÉTODOS: foi realizada revisão não sistemática da literatura para identificar artigos completos, cujos títulos destacassem o termo 'mHealth' e/ou 'Smart wearable', publicados nos últimos 15 anos. RESULTADOS: foram identificadas 467 publicações em periódicos indexados ao portal da Capes, 75 delas levadas em consideração pela análise; foram consolidadas evidências quanto às novas possibilidades decorrentes da disseminação da saúde móvel, aglutinadas segundo as categorias 'monitoramento de condições de saúde', 'transmissão de informações e análises de dados' e 'diagnóstico e terapêutica'. CONCLUSÃO: os trabalhos revisados sugerem que a oferta de serviços de saúde sofrerá alterações ao longo dos próximos anos, no que tange às categorias analisadas, o que exigirá um esforço de adaptação por parte dos profissionais de saúde, acadêmicos e usuários.

OBJECTIVE: to review and discuss new perspectives for healthcare provision resulting from the development of mobile health and intelligent wearable devices. METHODS: an unsystematic literature review was conducted to identify complete articles published in the last 15 years with titles highlighting the term 'mHealth' and/or 'Smart wearable'. RESULTS: 467 publications were identified in journals indexed on the CAPES portal, of which 75 were considered for analysis; evidence was then consolidated as to new possibilities arising from the spread of mobile health, grouped into the following categories: 'health status monitoring', 'information transmission and data analysis', and 'diagnosis and therapy'. CONCLUSION: the studies reviewed suggest that healthcare provision will change over the coming years with regard to the categories analyzed. This will require adaptation on the part of health professionals, academics and service users.

OBJETIVOS: revisar y discutir las nuevas perspectivas para la prestación de servicios de salud resultantes del desarrollo de la salud móvil (mHealth) y los dispositivos portátiles inteligentes. MÉTODOS: revisión narrativa, no sistemática, de la literatura para identificar artículos completos, cuyos títulos destacasen el termino 'mHealth' y/o 'Smart wearable', publicados en los últimos 15 años. RESULTADOS: se identificaron 467 publicaciones de revistas indexadas por el portal Capes de las cuales 75 fueron consideradas; así se consolidaron las evidencias sobre las nuevas posibilidades que surgen de la propagación de la salud móvil, vinculadas a las categorías 'monitoreo del estado de salud', 'transmisión de información y análisis de datos', y 'diagnóstico y terapéutica'. CONCLUSIÓN: los estudios analizados sugieren que la oferta de servicios de salud va a cambiar en los próximos años, con respecto a las categorías analizadas, lo que requerirá un esfuerzo de adaptación por parte de los profesionales de salud, académicos y usuarios.

Ossos ID: uma proposta de banco de dados didático de peças anatômicas para área da saúde / Bones ID: a proposal of didactic database of anatomic parts to health area / Huesos ID: una propuesta de base de datos educativos de estructuras anatómicas para la área de salud

Objetivo: Desenvolvimento e padronização de uma base de dados didática para armazenamento de informações relacionadas às coleções de peças osteológicas humanas acondicionadas no ossário do Departamento de Morfologia da Universidade Federal do Ceará. Método: A presente pesquisa trata-se de um estudo descritivo-exploratório executado em três etapas distintas: na primeira, foi desenvolvida a base de dados OssosID; na segunda etapa foi realizado a aplicação da base de dados OssosID e a terceira etapa consistiu na disponibilização da base de dados OssosID em nuvem, a partir do uso de software gratuito disponível online. Resultados e Conclusão: Após o desenvolvimento, aplicação e disponibilização da base de dados OssosID,foi possível observar que esta plataforma tornou-se viável para o seu uso contínuo e de rotina nas atividades do Departamento de Morfologia da Universidade Federal do Ceará, podendo servir como modelo para outras instituições de ensino e pesquisa devido a sua facilidade de operação e uniformidade.

Objective: Development and standardization of a didactic database to storage information related to human osteological collections of stored pieces in the ossuary of the Department of Morphology (DM) of the Federal University of Ceará (UFC). Method: The present research it is about a study descriptive and exploratory executed in three distinct stages: at first, was developed the based data: OssosID; at the second stage was performed the implementation of the OssosID and the third step consisted in providing the database OssosID in cloud by using a free software available online. Results and Conclusion: After the development, application and availability of the basedata: OssosID, we could observe that this platform has become viable for its continued and routine use in the activities of the Department of Morphology, Federal University of Ceará, and it can be used as a model for other institutions of education and research, by its easy operation and uniformity.

Objetivo: Desarrollo y normalización de una base de datos de enseñanza para almacenar información relacionada con las colecciones osteológicas de datos piezas que se conservan en el osario del Departamento de Morfología (DM) de la Universidad Federal de Ceará (UFC). Método: La presente investigación es un estudio descriptivo y exploratorio, ejecutado en tres etapas distintas: en primer lugar, fue desarrollado el base de datos: OssosID; la segunda etapa se llevó a cabo la aplicación de la base de datos OssosID y el tercer paso consistió en el suministro de el base OssosID nube de la utilización de software libre disponible en línea. Resultados y Conclusión: Después del desarrollo, la aplicación y la disponibilidad de los datos OssosID base, se observó que esta plataforma sea posible para su uso continuado y rutinaria en las actividades del Departamento de Morfología de la Universidad Federal de Ceará, pueden servir como un modelo para otras instituciones educativas y de investigación, debido a su facilidad de operación y la uniformidad.

A robust nanoscale biomemory device composed of recombinant azurin on hexagonally packed Au-nano array.

We developed a nanoscale memory device consisting of signal-responsive biomaterial, which is capable of switching physical properties (such as electrical/electrochemical, optical, and magnetic) upon application of appropriate electrical signals to perform memory switching. Here, we propose a highly robust surface-confined switch composed of an electroactive cysteine-modified azurin immobilized on an Au hexagonal pattern formed on indium tin oxide (ITO) substrates that can be controlled electrochemically and reversibly converted between its redox states. The memory effect is based on conductance switching, which leads to the occurrence of bistable states and behaves as an extremely robust redox switch in which an electrochemical input is transduced into optical and magnetic outputs under ambient conditions. The fact that this molecular surface switch, operating at very low voltages, can be patterned and addressed locally, and also has good stability and excellent reversibility, makes it a promising platform for nonvolatile memory devices.

Detection of charge storage on molecular thin films of tris(8-hydroxyquinoline) aluminum (Alq3) by Kelvin force microscopy: a candidate system for high storage capacity memory cells.

Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq(3)) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq(3) films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq(3) films, even for high hole and electron densities of >10(12) cm(-2). We show that this finding is consistent with the very low mobility of charge carriers in Alq(3) thin films (<10(-7) cm(2)/(Vs)) and that it can benefit from the use of Alq(3) films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq(3) molecules as the floating gate are fabricated and measured, showing durability over more than 10(4) program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10(13) cm(-2). These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells.

Multifunctional 4-bit biomemory chip consisting of recombinant azurin variants.

We developed a multi-functional 4-bit biomemory chip that consisted of recombinant azurin variants. The azurin was modified to introduce cysteine-residues. In addition, the Cu ion in this recombinant azurin protein was substituted with various other metal ions such as Co, Mn, Fe and Ni ion to allow the protein to perform various memory functions. Each metal-substituted recombinant protein was directly self-assembled attached onto Au surface via the thiol group of the cysteine. UV-VIS spectroscopy was performed to confirm the metal substitution. Atomic force microscopy was used to measure the film organization. Also, the 4 different azurin variants were investigated to assess the electrochemical behavior. Cyclic voltammetry and an open circuit potential indicated that the azurin variants had different redox peaks and specific open circuit potential values. Using these parameters, memory function was verified by chronoamperometry and open circuit potential amperometry. Therefore, a multi-bit biomemory chip was successfully developed. The results presented here provide a new approach, concept and material combination for the development of biomemory systems using recombinant protein. If a low electrochemical signal from a few single proteins could be achieved, it may be possible to substitute silicon-based memory devices with biological-based memory devices.

Ferredoxin molecular thin film with intrinsic switching mechanism for biomemory application.

A biomemory device consisting of cysteine modified ferredoxin molecules which possess a memory effect via a charge transfer mechanism was developed. For achieving an efficient bioelectronic device, cysteine modified ferredoxin was developed by embodying cysteine residues in ferredoxin by site--directed mutagenesis method to directly coordinate with the gold (Au) surface without use of any additional linkers. The thin film formation of ferredoxin molecules on Au electrode is confirmed by surface plasmon resonance (SPR) spectroscopy and scanning tunneling microscope (STM). Cyclic voltammetry (CV) and open circuit potential amperometry (OCPA) methods were used to verify the memory switching characteristics of the fabricated device. The charge transfer between ferredoxin protein molecules and Au electrode enables a bi-stable electrical conductivity allowing the system to be used as a digital memory device. Data storage is achieved by applying redox voltages which are within the range of -500 mV. These results suggest that the proposed device has a function of memory and can be used for the construction of a nano-scale bioelectronic device.

Verification of surfactant CHAPS effect using AFM for making biomemory device consisting of recombinant azurin monolayer.

In this study, a protein-based biomemory device was developed using a surface modified recombinant azurin layer and its surface characteristics were analyzed by atomic force microscopy. The cysteine-modified azurin used for this purpose was a metalloprotein that had redox properties. To immobilize the metalloprotein on the Au substrates, the cysteine-modified azurin layer was self-assembled on the Au surface through a covalent bond between the thiol group on the cysteine and the Au surface. In our previous work, we showed that this protein layer was formed as cohesive clusters on Au surface through physical adsorption. To reduce the formation of these cohesion clusters, a zwitterionic surfactant, (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate) (CHAPS) was introduced to modify the surface properties. Using this approach, we found that CHAPS significantly reduced the amount of cysteine-modified azurin aggregates that nonspecifically adsorbed to the Au substrate. Atomic force microscopy was used to analyze the modified-surface. Based on this analysis, the size of the recombinant azurin clusters when CHAPS was used were about 15-25nm whereas aggregates of 150-200nm were observed in the absence of CHAPS. In addition, Raman spectroscopy was performed to confirm the retention of azurin molecules self-assembled on the Au surface. Electrochemical results using cyclic voltammetry indicated that recombinant azurin was successfully immobilized onto the Au surface with CHAPS and its redox property remained intact. Chronoamperometry was then used to demonstrate the memory characteristics of this azurin-based fabricated memory device. The combined results of this study show that CHAPS can significantly reduce the size of protein aggregates that become immobilized on the surface without a loss of the electrochemical properties of the protein.

Nanoscale protein-based memory device composed of recombinant azurin.

In this present study, a nanoscale protein-based memory device consisting of recombinant azurin with its cysteine residues modified by site-directed mutagenesis method has been developed. Cysteine residues were modified to directly coordinate with the gold surface without use of any chemical linkers. Cyclic voltammetry (CV) method was used to measure the redox behavior of the immobilized azurin. Open-circuit potential amperometry (OCPA) technique allowed observing the memory characteristics including "write", "erase" and "read" functions of a nanoscale memory device. The variations in topology and the electron transfer properties, under the application of redox potentials, of the azurin adsorbed on Au was accomplished with electrochemical scanning tunneling microscopy. Data storage is achieved by applying redox potentials which are within the range of 500 mV. Finally the reliability of the proposed device has been examined. The key performance of the present system is it enables the memory working mechanism at nanoscale without degradation in performance and hence can be used as a nanoscale information storage device.

USB drives for communication of medical information in a pediatric dialysis unit.

We evaluated the feasibility of using universal serial bus (USB) drives for communicating medical information between parents of children receiving dialysis and medical personnel during clinical encounters. When surveyed, parents and pediatric resident physicians supported the use of USB drives and were willing to use the devices. The utilization rate of USB drives was 57%.

Selection of examples in case-based computer-aided decision systems.

Case-based computer-aided decision (CB-CAD) systems rely on a database of previously stored, known examples when classifying new, incoming queries. Such systems can be particularly useful since they do not need retraining every time a new example is deposited in the case base. The adaptive nature of case-based systems is well suited to the current trend of continuously expanding digital databases in the medical domain. To maintain efficiency, however, such systems need sophisticated strategies to effectively manage the available evidence database. In this paper, we discuss the general problem of building an evidence database by selecting the most useful examples to store while satisfying existing storage requirements. We evaluate three intelligent techniques for this purpose: genetic algorithm-based selection, greedy selection and random mutation hill climbing. These techniques are compared to a random selection strategy used as the baseline. The study is performed with a previously presented CB-CAD system applied for false positive reduction in screening mammograms. The experimental evaluation shows that when the development goal is to maximize the system's diagnostic performance, the intelligent techniques are able to reduce the size of the evidence database to 37% of the original database by eliminating superfluous and/or detrimental examples while at the same time significantly improving the CAD system's performance. Furthermore, if the case-base size is a main concern, the total number of examples stored in the system can be reduced to only 2-4% of the original database without a decrease in the diagnostic performance. Comparison of the techniques shows that random mutation hill climbing provides the best balance between the diagnostic performance and computational efficiency when building the evidence database of the CB-CAD system.

Conducting polymer memory devices based on dynamic doping.

Molecular electronic junctions consisting of a 20 nm thick layer of polypyrrole (PPy) and 10 nm of TiO2 between conducting layers of carbon and gold were investigated as potential nonvolatile memory devices. By making the polymer layer much thinner than conventional polymer electronic devices, it is possible to dynamically oxidize and reduce the polypyrrole layer by an applied bias. When the electrode in contact with the PPy is biased positive, oxidation of the PPy occurs to yield a conducting polaron state. The junctions exhibit a large increase in conductance in response to the positive bias, which is reversed by a subsequent negatively biased pulse. Switching between the conducting and nonconducting state can occur for pulses at least as short as 10 micros, and the conducting state persists after a positive bias pulse for at least 1 week. The read/write/read/erase cycle may be repeated for at least 1700 cycles, although with an error rate of approximately 3% due mainly to an incomplete "erase" step. The speed and retention of the PPy/TiO2 junctions are far superior to those of the analogous fluorene/TiO2 devices lacking the polymer, and the conductance changes are absent if SiO2 is substituted for TiO2. The observations are consistent with "dynamic doping" of the solid-state polymer layer, with the possible involvement of adventitious mobile ions. Although the speed of the current polymer/TiO2 junctions is slower than commercial dynamic random access memory, their retention is approximately 5 orders of magnitude longer.

Cancer incidence among semiconductor and electronic storage device workers.

AIMS: To evaluate cancer incidence among workers at two facilities in the USA that made semiconductors and electronic storage devices. METHODS: 89 054 men and women employed by International Business Machines (IBM) were included in the study. We compared employees' incidence rates with general population rates and examined incidence patterns by facility, duration of employment, time since first employment, manufacturing era, potential for exposure to workplace environments other than offices and work activity. RESULTS: For employees at the semiconductor manufacturing facility, the standardised incidence ratio (SIR) for all cancers combined was 81 (1541 observed cases, 95% confidence interval (CI) 77 to 85) and for those at the storage device manufacturing facility the SIR was 87 (1319 observed cases, 95% CI 82 to 92). The subgroups of employees with > or =15 years since hiring and > or =5 years worked had 6-16% fewer total incidents than expected. SIRs were increased for several cancers in certain employee subgroups, but analyses of incidence patterns by potential exposure and by years spent and time since starting in specific work activities did not clearly indicate that the excesses were due to occupational exposure. CONCLUSIONS: This study did not provide strong or consistent evidence of causal associations with employment factors. Data on employees with long potential induction time and many years worked were limited. Further follow-up will allow a more informative analysis of cancer incidence that might be plausibly related to workplace exposures in the cohort.

Digital video recording and archiving in ophthalmic surgery.

Currently most ophthalmic operating rooms are equipped with an analog video recording system [analog Charge Couple Device camera for video grabbing and a Video Cassette Recorder for recording)]. We discuss the various advantages of a digital video capture device, its archiving capabilities and our experience during the transition from analog to digital video recording and archiving. The basic terminology and concepts related to analog and digital video, along with the choice of hardware, software and formats for archiving are discussed.

Exposure assessment for retrospective follow-up studies of semiconductor- and storage device-manufacturing workers.

OBJECTIVE: This exposure assessment was conducted in the first large study of mortality and cancer incidence in semiconductor and storage device manufacturing. METHODS: Unique combinations of division, department and job codes and names (DDJ) from work history records were assigned to work groups and exposure categories. Agent exposure matrices assessed differences in potential exposures between groups. Changes in exposure over time were tracked by dividing the production history into manufacturing eras. RESULTS: Nineteen work groups were developed to capture 310,351 unique DDJs from 1965-1999. Agent exposure matrices contrasted exposure potential to solvents, metals, and work in cleanrooms between groups, and three manufacturing eras were identified for each site. CONCLUSIONS: The work groups, manufacturing eras and agent matrices have been used to classify workers in the study of cancer incidence and mortality.

Mortality among semiconductor and storage device-manufacturing workers.

PROBLEM: We evaluated mortality during 1965 to 1999 among 126,836 workers at two semiconductor facilities and one storage device facility. METHOD: We compared employees' cause-specific mortality rates with general population rates and examined mortality patterns by facility, duration of employment, time since first employment, and work activity. RESULTS: Employees had lower-than-expected mortality overall (6579 observed deaths, standardized mortality ratio [SMR] = 65; 95% confidence interval [CI] = 64-67), for all cancers combined (2159 observed, SMR = 78, 95% CI = 75-81) and for other major diseases. Central nervous system cancer was associated with process equipment maintenance at one of the semiconductor facilities (10 observed, SMR = 247, 95% CI = 118-454). Prostate cancer was associated with facilities/laboratories at the storage device facility (18 observed, SMR = 198, (5% CI = 117-313). CONCLUSIONS: Further evaluation of workplace exposures or independent investigations of similar occupational groups may clarify the interpretation of associations observed in this study.

Digitizing stereoscopic optic nerve head photographs for storage and viewing using a personal computer.

Careful examination and monitoring of optic nerve head changes is essential in the treatment of patients with glaucoma. This often results in accumulation of numerous photographs and required appropriate storage space. A simple, inexpensive, and efficient means of storing and viewing stereoscopic optic nerve head photographs is described. Images were acquired with a fundus camera, on a color slide film. Slides were then scanned and digitized. A handheld stereoscope was used for stereoscopic viewing on a computer monitor. A scanning resolution of 300 dpi appeared optimal. At this resolution, the storage utilization was 16 kilobytes and the scanning time was 160 seconds per patient.