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Geiger counter [keywords]
- Noninvasive in-vehicle alcohol detection with wavelength-modulated differential photothermal radiometry. [Journal Article]
- Biomed Opt Express 2014 Jul 1; 5(7):2333-40.
This study describes the potential of wavelength-modulated differential photothermal radiometry (WM-DPTR) for non-invasive in-vehicle alcohol detection which can be of great importance in reducing alcohol-impaired driving. Ethanol content in the range of concern, 0-100 blood alcohol concentration (BAC) in water phantoms and blood serum diffused in human skin in vitro were measured with high sensitivity. The results show that the WM-DPTR system can be optimized for alcohol detection with the combination of two sensitivity-tuning parameters, amplitude ratio R and phase shift ΔP. WM-DPTR has demonstrated the potential to be developed into a portable alcohol ignition interlock biosensor that could be fitted as a universal accessory in vehicles.
- PERFORMANCE OF RADIATION SURVEY METERS IN X- AND GAMMA-RADIATION FIELDS. [JOURNAL ARTICLE]
- Radiat Prot Dosimetry 2014 Jul 25.
The aim of this work was to investigate the different types of radiation detectors commonly used for radiation protection purposes as survey meters. The study was performed on survey meters that use different detectors as ionisation chamber, Geiger Mueller (GM) counter and scintillation detector. For each survey meter, energy dependence and angular response in X- and gamma-radiation fields was tested. The following commercially available survey meters were investigated: ionisation chambers Victoreen 451P, Babyline 31 and VA-J-15A, Geiger counter MRK-M87, 6150 AD6 and FAG FH 40F2 and scintillation counter 6150 ADB. As a source of gamma radiation, (137)Cs and (60)Co were used whereas X-ray radiation fields were generated using an X-ray unit. The radiation characteristics of the survey meters were mostly in compliance with references estimated by standard IEC 1017-2. However, some of them showed larger deviation at lower energies. GM counters exhibit strong energy dependence for low-energy photons.
- Low-dose spiral CT screening and evaluation of the solitary pulmonary nodule. [Journal Article]
- Oncology (Williston Park) 2014 May; 28(5):441-6.
Lung cancer screening using helical low-dose computerized tomography (LDCT) increased drastically after publication of a successful well-designed prospective randomized screening study, the National Lung Screening Trial. This increase in screening has led to a significant increase in the diagnosis of solitary pulmonary nodules (SPNs). Some of these lesions are early cancers, and their removal can potentially prevent a lung cancer death. Some have the histologic appearance of a cancer but will never progress and cause harm. Some are non-neoplastic and are best observed. The number of lesions detected with LDCT is so great that algorithms are being developed for more efficient evaluation and management of SPNs. This article will discuss current tools, approaches, and concerns regarding patient care in this setting.
- The use of technology to reduce radiation exposure in trauma patients transferred to a level I trauma center. [Journal Article]
- W V Med J 2014 May-Jun; 110(3):14-8.
Patients with traumatic injuries transferred from rural hospitals to tertiary centers in West Virginia frequently undergo repeat computed axial tomography (CT) imaging upon arrival. The traditional method of sending images on a compact disc (CD) with EMS can be unreliable due to software incompatibility, CD malfunction, or misplacement of the CD. Given the known risks associated with ionizing radiation, physicians are increasingly aware of the need to avoid unnecessary CT imaging. Image storage applications such as ImageGrid provide a means to store images securely without the issues and inherent problems of a CD. These images can be uploaded at the referring hospital and may be viewed from any computer at the receiving facility, by multiple providers--even prior to patient arrival. The goal of this study was to determine if utilizing ImageGrid compared to traditional data transfer by CD resulted in a decrease in the amount and type of images obtained in the initial Emergency Department (ED) evaluation at the tertiary center.We analyzed data from the Jon Michael Moore Trauma Registry for patients transferred to the Emergency Department at WVU Hospitals from an outside facility. Two study periods were reviewed; prior to ImageGrid implementation and after implementation of the system. Medical records of all patients admitted to the Trauma Surgery Service after a trauma system activation in the ED were reviewed during these time periods. Number and type of CT studies obtained in the Emergency Department were recorded for analysis.In the month of July 2010, 183 patients were admitted to the Trauma Surgery service after trauma team activation. Transfers from referring hospitals accounted for 77 of the 108 (42.1%). WVU Hospitals implemented ImageGrid during 2011. In July 2012, 243 patients were admitted to the Trauma Service, of which 105 (41.1%) were transfer patients. After implementation of ImageGridTM there was a significant decrease in the number of repeat CT Scans of the brain (19/27 [70.4%] vs. 18/40 [45.0%], p < .05), as well as CT scans of the chest, abdomen or chest/ abdomen/pelvis (9/18 [50.0%] vs. 2/23 [8.7%], p < .05). CT of the face showed a decreasing trend (5/9 [55.6%] vs. 1/9 [11%], p > .05 [p = 0.06]), but did not achieve statistical significance. After implementation of ImageGrid there was a marked decrease in total CT scans repeated (46/79 [58.2%] vs. 28/107 [26.2%], p < .05).In West Virginia, the use of image archival systems such as ImageGrid appears to result in less repeat CT imaging upon arrival at a tertiary trauma center. Given risks associated with ionizing radiation and costs of repeat imaging the benefits have important implications for patient safety and cost containment.
- Development and Evaluation of Novel PET Tracers for Imaging Cannabinoid Receptor Type 2 in Brain. [JOURNAL ARTICLE]
- Chimia (Aarau) 2014 Apr; 68(4):208-210.
The cannabinoid receptor type 2 (CB2) has a very low expression level in brain tissue under basal conditions, but it is up-regulated in diverse pathological conditions. Two promising lead structures from the literature, N-((3S,5S,7S)-adamantan-1-yl)-8-methoxy-4-oxo-1-pentyl-1,4-dihydroquinoline-3-carboxamide and 8-butoxy-N-(2-fluoro-2-phenylethyl)-7-methoxy-2-oxo-1,2-dihydroquinoline-3-carboxamide - designated KD2 and KP23, respectively - were evaluated as potential PET ligands for imaging CB2. Both KD2 and KP23 were synthesized and labeled with carbon-11. In vitro autoradiographic studies on rodent spleen tissues showed that [(11)C]KD2 exhibits superior properties. A pilot study using [(11)C]KD2 on human post mortem ALS spinal cord slices indicated high CB2 expression level and specific binding, a very exciting finding if considering the future diagnostic application of CB2 ligands and their utility in therapy monitoring. In vivo blocking studies in rats with [(11)C]KD2 showed also high specific uptake in spleen tissue. Although the protein-bound fraction is relatively high, KD2 or KD2 derivatives could be very useful tools for the non-invasive investigation of CB2 levels under various neuroinflammatory conditions.
- Insights from a thermography-based method suggesting higher carotid inflammation in patients with diabetes mellitus and coronary artery disease. [JOURNAL ARTICLE]
- Diabetes Metab 2014 Jun 26.
Diabetes mellitus (DM) is an independent risk factor for stroke. In a DM population, carotid atheromatosis is a major cause of stroke. The role of carotid plaque inflammation remains conflicting. Microwave radiometry (MWR) is a new non-invasive method allowing in vivo measurement of the temperature of tissues, so reflecting inflammation. The aim of this prospective study was to evaluate the impact of DM on carotid artery inflammation in patients with documented coronary artery disease (CAD).Consecutive patients (n=300) with significant CAD were evaluated by: (1) ultrasound study of both carotid arteries; and (2) the temperature difference (ΔT) along each carotid artery on MWR. ΔT≥0.90°C was considered high ΔT. Vessel- and patient-based analyses were performed to determine the impact of DM on morphological and functional characteristics of carotid arteries.Out of 300 patients, 113 (37.7%) had DM. Patients with DM had similar carotid plaque thickness compared with patients without DM in both vessel- and patient-based analyses. In contrast, patients with DM exhibited higher ΔT values in both vessel- and patient-based analyses. On multivariate logistic regression analysis, DM was an independent predictor of high ΔT both unilaterally and bilaterally (OR: 1.66, 95% CI: 1.06-2.58, P=0.03 and OR: 1.96, 95% CI: 1.01-3.81, P=0.05, respectively).In patients with CAD, DM was an independent predictor of local carotid plaque inflammatory activation. Whether or not the assessment of functional plaque characteristics by MWR can be an additional prognostic tool independent of structural factors now needs to be further investigated.
- In vitro assessment of commercial sunscreens available in Latin America. [Journal Article]
- Invest Clin 2014 Jun; 55(2):142-54.
In Latin America, people have largely abandoned the practice of wearing hats and traditional clothing that provided skin protection. Sunscreen application has therefore become essential to protect against the increased sun exposure. The physician-prescribed medical-grade sunscreens provide sufficient sun protection but the requirement for regular use puts a financial burden on the patient that is often not sustainable. An appropriate sunscreen should provide a high and broad ultraviolet (UV) protection against UVB and UVA. Several over-the-counter (OTC) sunscreens have been developed for sale at affordable prices and are available for purchase in convenient locations, such as local grocery stores. The aim of this study was to assess the in vitro UV protection of 34 popular OTC sunscreens found in the Latin American market. UV absorbance/transmittance was quantified by diffusion transmission spectroscopy using coarse silica plaques. Photostability was tested by irradiating them with simulated solar light and calculating the sun protection factor (SPF), critical length of absorption (C lambda ), UVA/UVB ratio, and the spectral uniformity index (SUI). The results indicated that the in vitro SPFs were significantly lower than the value declared on the labels, particularly for those claiming high SPF values; however, the majority of these sunscreens offered high levels of UV protection. Considering the advantages of low cost and ample accessibility, we concluded that this sample of OTC sunscreens can be beneficial to the general public by providing some level of skin protection from solar radiation, and may be promoted to improve compliance with recommended photoprotection behavior.
- What is a safe level of radiation? [Letter]
- Aust Orthod J 2014 May; 30(1):89-90.
- Shall I go digital? [Journal Article]
- Dent Update 2014 May; 41(4):314-6, 319-22, 325-6.
Dental radiographic imaging is slowly transferring to digital format. The decision to invest in this new technology should be based on a good understanding of the different types of digital imaging available within the dental field. This article outlines its use in general dental practice, highlighting the pros and cons of the various systems both for intra-oral and extra-oral radiography. Clinical Relevance: An understanding of the mechanisms of digital imaging and their associated potential problems are required by any clinician moving to film-less imaging.
- Comparison of Radiation-Induced Normal Lung Tissue Density Changes for Patients From Multiple Institutions Receiving Conventional or Hypofractionated Treatments. [JOURNAL ARTICLE]
- Int J Radiat Oncol Biol Phys 2014 Jul 1; 89(3):626-632.
To quantitatively assess changes in computed tomography (CT)-defined normal lung tissue density after conventional and hypofractionated radiation therapy (RT).The pre-RT and post-RT CT scans from 118 and 111 patients receiving conventional and hypofractionated RT, respectively, at 3 institutions were registered to each other and to the 3-dimensional dose distribution to quantify dose-dependent changes in normal lung tissue density. Dose-response curves (DRC) for groups of patients receiving conventional and hypofractionated RT were generated for each institution, and the frequency of density changes >80 Hounsfield Units (HU) was modeled depending on the fractionation type using a Probit model for different follow-up times.For the pooled data from all institutions, there were significant differences in the DRC between the conventional and hypofractionated groups; the respective doses resulting in 50% complication risk (TD50) were 62 Gy (95% confidence interval [CI] 57-67) versus 36 Gy (CI 33-39) at <6 months, 48 Gy (CI 46-51) versus 31 Gy (CI 28-33) at 6-12 months, and 47 Gy (CI 45-49) versus 35 Gy (32-37) at >12 months. The corresponding m values (slope of the DRC) were 0.52 (CI 0.46-0.59) versus 0.31 (CI 0.28-0.34) at <6 months, 0.46 (CI 0.42-0.51) versus 0.30 (CI 0.26-0.34) at 6-12 months, and 0.45 (CI 0.42-0.50) versus 0.31 (CI 0.27-0.35) at >12 months (P<.05 for all comparisons).Compared with conventional fractionation, hypofractionation has a lower TD50 and m value, both suggesting an increased degree of normal tissue density sensitivity with hypofractionation.