Maximum Spherical Mean Value (mSMV) Filtering for Whole Brain Quantitative Susceptibility Mapping

To develop a tissue field filtering algorithm, called maximum Spherical Mean Value (mSMV), for reducing shadow artifacts in quantitative susceptibility mapping (QSM) of the brain without requiring brain tissue erosion.Residual background field is a major source of shadow artifacts in QSM. The mSMV algorithm filters large field values near the border, where the maximum value of the harmonic background field is located. The effectiveness of mSMV for artifact removal was evaluated by comparing with existing QSM algorithms in numerical brain simulation as well as using in vivo human data acquired from 11 healthy volunteers and 93 patients. Numerical simulation showed that mSMV reduces shadow artifacts and improves QSM accuracy. Better shadow reduction, as demonstrated by lower QSM variation in the gray matter and higher QSM image quality score, was also observed in healthy subjects and in patients with hemorrhages, stroke and multiple sclerosis. The mSMV algorithm allows QSM maps that are substantially equivalent to those obtained using SMV-filtered dipole inversion without eroding the volume of interest.Comment: 12 pages, 5 figure

Attitudes to and management of fertility among primary health care physicians in Turkey: An epidemiological study

BACKGROUND: The subject of infertility has taken its place in the health sector at the top level. Since primary health care services are insufficient, most people, especially women, keep on suffering from it all over the world, namely in underdeveloped or developing countries. The aim of this study was to determine primary care physicians' opinions about the approach to infertility cases and their place within primary health care services (PHCSs). METHODS: The study was conducted between October 2003 and April 2004. The study group comprised 748 physicians working in PHCSs. They were asked to fill in a questionnaire with questions pertaining to infertility support, laboratory and treatment algorithms, as well as the demographic characteristics. The data was evaluated using the chi square test, percentage rates and a logistic regression model. RESULTS: The multivariate analyses showed that having a previous interest in infertility and having worked for a postgraduate period of between 5–9 years and ≥10 years were the variables that most positively influenced them in their approach to cases of infertility (p < 0.05, each one). Just 28.7% of the physicians indicated that they believed cases of infertility could be evaluated at the primary care level. The most frequently proposed reason for indicating 'difficulty in practice' (n = 533) was inadequate provision of equipment in PHCSs (55.7%). The physicians reported that they were able to perform most of the supportive treatments and proposals (between 64.6%–87.7%). The most requested laboratory investigations were the instruction of patients in taking basal body temperatures and semen analysis (89.7% and 88.7%, respectively). The most preferential course of treatment was that of sexually transmitted diseases (95.5%). CONCLUSION: It is clear that not enough importance is attached to the provision of care to infertile couples within PHCSs. This leads us to conclude that an integration of infertility services in primary care would be appropriate after strengthening the PHCSs

Design and Evaluation of a Greenhouse Interface for Climate Control Programming and Networking

At Cal Poly the motto is “Learn by Doing”. In the College of Agriculture, this is especially true and many of the labs provide an opportunity for students to implement this philosophy. Updated climate controls were installed in a series of greenhouses on the top floor of the Agricultural Science building that are used for student and faculty research projects. A Programmable Logic Controller (PLC) was installed to actuate the various vents, shading, heating, cooling and irrigation. A control program was developed to control and log temperatures and other operating parameters to monitor the greenhouse. An easy to use computer program was developed that is able to be accessed from a network web site. Implementation of this interface allows students and faculty to carry out projects and to keep accurate records of the environmental conditions affecting their research. The program emulates the previous control system so that it will be easy to use, but also offers other options not available before. This greenhouse allows for engineering students to develop additional control programs and gives them hands on experience and insight into their operation and function

Optical Detection of Fat Concentration in Milk Using MXene-Based Surface Plasmon Resonance Structure

MXene (Ti3C2Tx) has emerged very recently as an interacting material for surface plasmon resonance (SPR) configuration. It was discovered that Ti3C2Tx can facilitate the adsorption of biomolecules due to its higher binding energies, stronger interaction between matter and light, and larger surface area. In this work, a two-dimensional Ti3C2Tx and silicon layer-based SPR refractometric sensor is proposed for the sensitive and fast detection of milk fat concentration due to the high significance of this issue to people all over the world. The proposed SPR structure employs BK7 (BK7 is a designation for the most common Borosilicate Crown glass used for a variety of applications in the visible range) as a coupling prism and silver as a metal layer. The layer thicknesses and the number of Ti3C2Tx sheets are optimized for the highest performance. The highest reached sensitivity is 350 deg./RIU with 50 nm silver and 4 nm silicon with a monolayer of Ti3C2Tx, which is ultra-high sensitivity compared to the latest work that utilizes SPR configuration. The proposed SPR-based sensor&rsquo;s ultra-high sensitivity makes it more attractive for usage in a variety of biosensing applications

Converter and Output Filter Topologies for STATCOMs

This chapter reviews different converter topologies and output filter configurations used in STATCOM applications. The output voltage and harmonic control of a STATCOM is obtained by individual control of each switch in the STATCOM. Several converter topologies can be considered for STATCOMs. The multi-pulse converters are developed using the most widely known 6-pulse configurations. The variations of multi-pulse converters such as 12-pulse, 24-pulse and 48-pulse that are built by combining 6-pulse converters via phase-shifting isolation transformers are introduced in terms of control methods and structures in this chapter. On the other hand, the multilevel converters are considered to be used in recent STATCOM topologies as an alternative to the multi-pulse configurations, owing to their multi MVA switching capability that is inherited from series or parallel connection of converter cells. The diode clamped, flying capacitor, and cascaded H-bridge configurations of multilevel converters, that are the most widely known topologies, are comprehensively introduced in this chapter. The multilevel converter topologies provide several advantages such as harmonic elimination, lower electromagnetic interference, better output waveforms, and increased power factor correction (PFC) capabilities together. Furthermore, each switch can be controlled individually to robustly tackle the unbalanced load operations even in higher switching frequencies relatively to the multi-pulse configuration. The related subsections propose control and operation properties of converters besides introducing the main topological issues. The filtering requirements of STATCOM are particularly considered in this chapter where the passive and active filters are introduced in detail. The passive filters designed with reactive components such as individual L and C or their combinations as LC or LCL are surveyed according to design and analytical criteria. Besides, active power filters (APFs) that provide several feedback control methods increasing the efficiency and controllability are discussed in the following part. The control methods of STATCOM converters are introduced in a separate section where the recent control approaches and analytical calculations required are presented in detail. The block diagrams of the industrial STATCOM applications are also discussed