Accumulated Exposure Time Research Articles

Dose of deferasirox correlates with its effects, which differ between low-risk myelodysplastic syndrome and aplastic anaemia.

Patients with low-risk myelodysplastic syndrome (MDS) and aplastic anaemia (AA) often need transfusions, which may accelerate iron overload. The aim of this study was to evaluate the efficacy, safety and dose-effect relationships of deferasirox (DFX) in patients with low-risk MDS and AA who were refractory to regular treatment in a real-world setting. Patient data were recorded, and dose-effect relationships of DFX were calculated after the first 6months. Total annual exposure to DFX was calculated after 12 months and expressed as the accumulated exposure time at a dosage of 20 mg/kg/day. Sixty-one patients with low-risk MDS and 51 with AA were enrolled. The minimum dosage of DFX needed for a significant serum ferritin (SF) decrease was 20 mg/kg/day at 6months, and the minimum accumulation of DFX had to reach 9months at 20 mg/kg/day by 12 months for patients with low-risk MDS. For patients with AA, the minimum dosage was 10mg/kg/day at 6months, and the minimum accumulation had to reach 3months at 20 mg/kg/day by 12 months. With the same exposure, significant improvements in haematological parameters were also observed in AA. Lower liver enzymes compared with baseline were observed. Gastrointestinal disorders and elevated serum creatinine were the most common side effects. Higher exposure to DFX correlated with longer overall survival (OS). A significant decrease in SF and an improvement in haematologic parameters, organ function and even OS can be achieved if the accumulated DFX dose reaches a certain level. Patients with low-risk MDS need a higher dose than those with AA.

Study of the influence of vibration treatment of coal cores as a way to increase gas permeability

This paper provides the results of a series of experimental studies on seismic action’s effect on the permeability of coal and hydraulic fractures. The experiments have been carried out using solid coal cores, cores with single through longitudinal cracks simulating drainage hydraulic fractures and cores with the single fractures propped with a low-density proppant designed to intensify the degassing of coal seams. The patterns of the seismic impact on the gas permeability of coal under the conditions of all-round compression have been established in accordance with the results of experiments. Also, the experimental results reveal certain patterns of increase of the drainage cracks’ gas permeability observed when the cracks are propped with proppant and are under the low intensity seismic effect under the conditions of all-round compression. The studies show that the effectiveness of seismic action increases with an increase in the accumulated exposure time, followed by stabilization and persistence of the positive effect for at least 3 - 7 days after the cessation of exposure. The obtained results provide the opportunity to assess the possibility of using seismic action to intensify the degassing of non-propped hydraulic fractures in coal mines.

Dose of Deferasirox Correlates with Effects but Is Different in Low-Risk Myelodysplastic Syndrome and Aplastic Anemia

▪Background: Patients with low-risk myelodysplastic syndrome (MDS) and aplastic anemia (AA) often need transfusions, which may accelerate the iron overload. The aim of this study was to evaluate the efficacy, safety and dose-effect relation of deferasirox (DFX) for patients with low-risk MDS and AA who were refractory to regular treatment in the real-world setting.Methods: This was a retrospective study. Patients with low-risk MDS or AA who failed to standard treatments and were transfusion-dependent were enrolled. DFX was given as the only treatment apart from transfusion. Patients were recorded for their medical history, laboratory tests, nuclear magnetic resonance (MRI), echocardiography and calculated for their overall survival (OS). Dose-effect relations of DFX were evaluated after the first 6 months. Total annual exposure of DFX was calculated after 12 months, expressed as accumulated exposure time at dose of 20mg/kg/d.Results: Of the 112 patients finally enrolled, 61 (54.5%) were low-risk MDS and 51 (45.5%) were AA. The median age was 56 (10, 89) years and 52.7% patients were males. The minimum dose of DFX for significant SF decrease was 20 mg/kg/d at 6 months; and the minimum accumulation of DFX had to reach 9 months at 20 mg/kg/d to maintain the efficacy at the time of 12 months for patients with low-risk MDS (p＜0.050). Different from MDS, the minimum dose for significant SF decrease was 10 mg/kg/d at 6 months; and the minimum accumulation had to reach 3 months at 20 mg/kg/d to maintain the efficacy at the time of 12 months for patients with AA (p＜0.050). Meanwhile, with same dose of exposure, significant improvements in hematological parameters were also observed in AA, but no dose-effect relations were found in MDS. 62.3% MDS and 51.0% AA patients stopped transfusion in the next 6 months. Erythroid responders had lower SF than non-responders after 12 months of DFX, both for MDS and AA (p＜0.05). Lower alanine aminotransferase (ALT) and aspartate aminotransferase (AST) compared with baseline after 12 months of DFX were observed and longer exposure time correlated with lower ALT (p＜0.050). No significant changes in cardiac function, however. Similar side effects were found in MDS and AA, with gastrointestinal disorders and elevated serum creatinine the most common. Higher dose and longer exposure time of DFX correlated with longer overall survival, both for patients with MDS and AA (p＜0.050).Conclusion: Although dose of DFX varies greatly in different individuals, a significant decrease in SF and an improvement of hematologic parameters, organ functions, or even overall survival can be achieved if the accumulate dose reaches a certain level. In that case, patients with low-risk MDS need higher dose than those with AA. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Experimental study of seismic action influence on gas permeability of coal and hydraulic fractures

Mine field development of coal deposits is currently associated with work at depths exceeding 400m. Under these conditions the gas content of promising horizons is one of the main factors constraining the pace of development. An integral part of gas-bearing coals’ extraction is their preliminary degassing. The methane recovery ratio affects the efficiency and safety of longwall work. Degassing is intensified in order to achieve the required values of methane content in coal seams. A well-known method employed to intensify filtration processes in fluid-saturated rocks is the elastic vibrations’ treatment. The laboratory tests and field work show the positive effect of elastic vibrations on the intensification of methane desorption from coal. Modern works in this field are devoted to investigation of connections between the parameters of vibration action and the degree of increase in the methane desorption. This paper provides the results of a series of experimental studies on seismic action’s effect on the permeability of coal and hydraulic fractures. The research has been carried out on a custom designed laboratory bench. The design of the stand provides the effect of elastic vibrations of small amplitude with independent regulation of the average and differential gas pressures, axial and lateral compression of the sample. The experiments have been carried out using solid coal cores, cores with single through longitudinal cracks simulating drainage hydraulic fractures and cores with the single fractures propped with a low-density proppant designed to intensify the degassing of coal seams. The patterns of the seismic impact on the gas permeability of coal under the conditions of all-round compression have been established in accordance with the results of experiments. Also, the experimental results reveal certain patterns of increase of the drainage cracks’ gas permeability observed when the cracks are propped with proppant and are under the low intensity seismic effect under the conditions of all-round compression. The studies show that the effectiveness of seismic action increases with an increase in the accumulated exposure time, followed by stabilization and persistence of the positive effect for at least 3 - 7 days after the cessation of exposure. The obtained results provide the opportunity to assess the possibility of using seismic action to intensify the degassing of non-propped hydraulic fractures in coal mines.

Under-exposure to official matches is associated with muscle injury incidence in professional footballers.

External workload from matches is considered one of the most important muscle injury risk factors for football teams. However, there is scarce published evidence to support this belief. This study examined whether a particular profile of external match workload existed prior to a muscle injury. A total of 144 professional football players belonging to 2 teams were monitored over three seasons. For each muscle injury, a profile of external workload variables was determined for 5 to 8 games and expressed as: time playing exposure, total distance (TD) covered and high-speed running (HSR) covered. In addition, acute:chronic workload ratio (ACWR) was calculated. Sixty players (41.6%) reported a total of 86 muscle injuries during the three seasons. Muscle injuries occurred principally in matches (79.1%), the hamstring being the most affected muscle (44.1%). Injured players displayed substantially lower accumulated exposure time (ES = 0.45), TD (ES = 0.45) and HSR (ES = 0.39) in comparison with uninjured players in the last 5 games prior to injury. Compared to the uninjured players, ACWR for exposure (ES = -0.29/0.02) and running load (ES = -0.24/0.00) did not differ between match 5 and 2 prior to the injury, although uninjured players displayed a substantially greater ACWR in all 3 variables (ES = 0.31/0.35) than injured players in match 1 prior to the injury. Lower playing exposure (minutes played) and associated reduced running distances (TD and HSR) were observed in injured football players. Being under-loaded in official games could be a mediator for muscle injury in this cohort of elite football players.

Occupational ionizing radiation-induced skin injury among orthopedic surgeons: A clinical survey

BackgroundThis study aimed to assess orthopedic surgeons’ attitudes and behaviors toward occupational radiation exposure and investigate the prevalence of occupational radiation-induced skin injury among orthopedic surgeons. Similarly, risk factors for the presence of radiation-induced skin injury were investigated. MethodsOverall, 108 orthopedic surgeons were administered self-reported questionnaires about occupational radiation exposure, and their hands were then photographed. Their fields of expertise were classified into spine, arthroplasty, sports medicine, hand, oncology, rheumatoid arthritis, pediatric orthopedic, and resident. Dermatologists evaluated the surgeons’ skin conditions and classified into 3 grades of injury: grade 0, no clinical symptoms; grade 1, careful observation required; and grade 2, detailed examination required. Logistic regression analysis was performed to investigate the factors related to the presence of radiation-induced skin injury. Crude and adjusted logistic regression analysis using the backward stepwise selection method was similarly conducted. Receiver operating characteristic curve (ROC) analysis was performed to estimate the predictive power of exposure time, occupational period, and accumulated annual exposure time for radiation-induced skin injury. ResultsIn total, 93.5% of the surgeons were careful about occupational radiation exposure, of which 76.8% used a dosimeter. Skin changes in the hands were self-reported by 42.5% of the surgeons, and radiation-induced skin injury was diagnosed in 31.4%. The accuracy of the self-reported skin changes was 100% for grade 2 and 61.5% for grade 1. Adjusted regression analysis showed that dermatologists’ diagnosis-related factors were self-reported skin changes (odds ratio [OR] 3.1) and spine surgeons (OR 3.2). ROC analysis demonstrated that an occupational period >21 years and an accumulated exposure time >6696 min were considered risk factors, with ORs of 4.07 and 5.99, respectively. ConclusionsOrthopedic surgeons, particularly spine surgeons, should be regularly examined by dermatologists early in their careers for early detection of radiation-induced skin injury on the hands.

Dry Eye Disease Association with Computer Exposure Time Among Subjects with Computer Vision Syndrome.

PurposeTo assess the time of exposure to the computer and dry eye disease (DED) in subjects with computer vision syndrome (CVS).MethodsA cross-sectional study was conducted in office workers, computer users of both sexes, with an age range of 18–45 years without comorbidities; we included 108 subjects divided into 3 groups according to the time of computer exposure in hours per day (H/D): <4 (n = 23), 4 −7.9 (n = 49), >8 (n = 39). A specific questionnaire was applied to them on the exposure time and the type of visual display terminal (VDT) used, as well as the computer vision symptoms scale (CVSS17). DED was diagnosed with the Ocular Surface Disease Index (OSDI). Ocular surface damage and signs of DED were evaluated with the tear rupture time test (TBUT), the integrity of the ocular surface by ocular surface staining (OSS) and the production of the aqueous basal tear film using the Schirmer test.ResultsAverage computer exposure time, measured differently, was positively correlated with DED development. The computer exposure time measured in hours per year and TBUT showed a significant negative correlation (p <0.001) (rho −0.463). Years of computer exposure and staining of the ocular surface showed a significant positive correlation (p <0 0.001; rho 0.404). The accumulated exposure time was negatively correlated with TBUT (p <0.001; rho −0.376) and positively with OSS (p <0.001; rho 0.433). Schirmer test did not correlate with computer exposure time.ConclusionThe prolonged time of exposure to the computer in subjects with CVS was significantly correlated with the DED tests, in the different ways of measuring it; but not with the Schirmer test.

Simultaneously Self-Inscribed Antisymmetric Long-Period Grating and Antisymmetric Apodized Fiber Bragg Grating in a Dual-Core As$_{2}$Se$_{3}$-PMMA Tapered Fiber

We report for the first time that transmission of optical light centered at a wavelength of 1549.8 nm through a tapered dual-core As $_{2}$ Se $_{3}$ -PMMA fiber simultaneously inscribes an antisymmetric long-period grating and an antisymmetric apodized fiber Bragg grating. The evolutions of the transmission spectrum, and the back-reflected spectrum of the dual-core fiber are experimentally measured as the accumulated exposure time increases. The bandwidth of the antisymmetric apodized fiber Bragg grating is measured, and a narrow bandwidth of 3.5 GHz (0.028 nm) with $\sim\! \text{100}\%$ reflectivity (∼32 dB contrast) is observed. A theoretical model of an antisymmetric apodized fiber Bragg grating in a dual-core fiber computationally reproduces the experimentally observed evolution of the transmission spectrum and the back-reflected spectrum. Both theory, and experiment reveal for the first time that such structure requires dual phase-matching conditions. It is also the first time that one single reflection peak of a fiber Bragg grating is observed on a dual-core multimode fiber that supports two modes due to the satisfying of dual-phase matching conditions. The performance of this device as an optical filter is investigated. The antisymmetric apodized structure provides a novel method for achieving apodized fiber Bragg gratings with narrow bandwidth, high reflectivity, and suppression of side-lobes. The simultaneously inscribed antisymmetric long-period grating and antisymmetric apodized fiber Bragg grating in the dual-core As $_{2}$ Se $_{3}$ -PMMA taper opens the path towards the realization of novel sensors and devices.

Magnetic Field Imaging of Superparamagnetic Particles Using High‐Density, Perfectly Oriented NV Centers in Diamond CVD Film

The spatial and temporal resolutions of bio‐imaging with magnetic nanoparticles (MNP) as a label and a diamond substrate as a magnetic field imager are investigated. To realize fast and accurate magnetic field imaging even for a substrate with unresolved hyperfine peaks, relative fluorescence is measured at four operation points corresponding to the steepest slopes of two dips in the ODMR spectrum. The (111) diamond substrate with a 3.5‐μm thick chemical vapor deposition film with an NV− density of 1.6 × 1016 cm−3 allows us to detect 1‐μm MNPs scattered on its surface with an accumulated exposure time of 19 s under external DC magnetic field of 1.3 mT. Theoretical limit of temporal sensitivity is estimated to be more than four orders of magnitude smaller than measured. Although for measurement in culture medium, an objective lens with longer working distance is required and the condition will become somewhat worse, a spatiotemporal resolution of &lt;1 s and &lt;1 μm for the density and quality of the NV centers used in this study is expected if the already reported sensitivity enhancement technologies are further incorporated.

THE X-RAY FLARING PROPERTIES OF Sgr A* DURING SIX YEARS OF MONITORING WITHSWIFT

Starting in 2006, Swift has been targeting a region of ~21'X21' around Sagittarius A* (Sgr A*) with the onboard X-ray telescope. The short, quasi-daily observations offer an unique view of the long-term X-ray behavior of the supermassive black hole. We report on the data obtained between 2006 February and 2011 October, which encompasses 715 observations with a total accumulated exposure time of ~0.8 Ms. A total of six X-ray flares were detected with Swift, which all had an average 2-10 keV luminosity of Lx (1-4)E35 erg/s (assuming a distance of 8 kpc). This more than doubles the number of such bright X-ray flares observed from Sgr A*. One of the Swift-detected flares may have been softer than the other five, which would indicate that flares of similar intensity can have different spectral properties. The Swift campaign allows us to constrain the occurrence rate of bright (Lx > 1E35 erg/s) X-ray flares to be ~0.1-0.2 per day, which is in line with previous estimates. This analysis of the occurrence rate and properties of the X-ray flares seen with Swift offers an important calibration point to asses whether the flaring behavior of Sgr A* changes as a result of its interaction with the gas cloud that is projected to make a close passage in 2013.

Intervals Before Tuberculosis Diagnosis and Isolation at a Regional Hospital in Taiwan

Background/PurposeNosocomial tuberculosis (TB) infection is still a problem in many Taiwanese hospitals. The objectives of this study were to explore the intervals before TB diagnosis and isolation at a regional hospital in Taiwan, and to provide useful knowledge to hospitals for the purpose of TB infection control.MethodsFrom 2002 to 2005, we included a total of 343 patients with culture-positive pulmonary TB in a regional hospital in Southern Taiwan for this study. Their medical records were reviewed, and the time intervals between patient-hospital contact points and isolation were recorded.ResultsOf 343 culture-positive pulmonary TB patients, the majority were male, over 40 years old, and unemployed. The mean interval between the first admission and isolation was 20.5 days (median, 2.0 days). The mean intervals between the first admission from outpatient clinics, emergency department and hospitalization and suspected TB were < 1 day, 6.07 days and 25.53 days, respectively. The mean accumulated exposure time was 0.35 days, 0.61 days and 10.09 days in outpatient clinics, the emergency department and hospitalization, respectively; 75.5% of patients had their diagnosis confirmed at the chest department of the department of internal medicine.ConclusionDelayed diagnosis was most likely in the case of hospitalized patients and least likely in outpatient clinics. Delayed diagnosis in hospitalized patients also contributed more severely to TB exposure time than others. Enhancing the quality, speed and ability of specialists and physicians to diagnose TB, especially in emergency departments and in hospitalized patients, is essential.

Ambulatory 24-hour esophageal pH monitoring: why, when, and what to do.

The incidence of gastroesophageal reflux disease (GERD) is increasing and if left untreated can lead to significant patient morbidity and even death. The disease results from the abnormal reflux of gastric contents into the distal esophagus causing symptoms in most and subsequent mucosal damage in some. Several investigations can be used to confirm the diagnosis, but most are dependent on the presence of sequelae and complications of the disease. The physiologic test of ambulatory 24-hour esophageal pH monitoring has proved to be the most sensitive and specific diagnostic investigation. It measures increased esophageal exposure to gastric juice by detecting the concentration of hydrogen ions (pH <4) in the distal esophagus. The technique measures gastric juice exposure at a point 5 cm above the manometrically determined upper border of the lower esophageal sphincter. The exposure is measured in components of frequency of reflux episodes, duration of reflux episodes, and accumulated exposure time. The components are integrated into a composite score, which is reproducible, gender and race independent, and correlates with the degree of esophageal epithelial damage determined histologically. The composite score has been shown to be the most reliable measurement of a therapeutic acid suppression regimen or an effective antireflux operation.

Frequency of liver disease in type 2 diabetic patients treated with oral antidiabetic agents.

We evaluated liver disease in conventionally treated type 2 diabetic patients to provide a reference against which reports of liver disease related to novel oral antidiabetic treatments could be compared. In this follow-up study, patients with type 2 diabetes who were treated with oral antidiabetic agents were identified from the U.K.-based General Practice Research Database and were followed to determine whether they developed liver disease. The specific types and etiologies of liver disorders were determined. Incidence rates were calculated based on the accumulated exposure time to oral antidiabetic agents. Among 44,406 type 2 diabetic patients, 605 had a computer diagnosis of liver disease with an incidence rate of 53.2/10,000 person-years (95% CI 49.2-57.6). Of the 605 subjects, 186 had nonsymptomatic, mild, and transient liver disorders; 249 had a predisposing condition; and 113 had another cause for the disease. A total of 57 cases were possibly drug induced with an incidence rate of 5.0/10,000 person-years (3.9-6.5). Of the cases, 11 were attributed to other drugs, 8 were attributed to fatty liver disease of diabetes, and the remaining cases were attributed to uncertain causes. Oral antidiabetic agents were continued in 51 of these 57 cases, and we could not rule out oral antidiabetic agents as a cause of liver disease in 2 cases with an incidence rate of 0.2/10,000 person-years (< 0.1-0.6). In this population, the background incidence of liver disease was high. Most cases involved other systemic diseases that may cause liver disease.

High Temperature Oxidation and Fracture Behavior of Silicon Nitrides.

Oxidation behavior of silicon nitride ceramics (SSN-1, SSN-2, SSN-3) was investigated in air environment at constant high temperature and under a thermal cycle condition. Flexural strengths were measured for specimens before and after oxidation at room and high temperature. ( 1 ) The formation of pits was observed for SSN-1 exposed at high temperature. The large pits resulted in strength degradation. ( 2 ) High-temperature strength of SSN-2 after oxidation did not change due to the disappearance of cracks by melting of the oxidized layer. ( 3 ) Strength degradation of SSN-3 was 40 % after thermal cycle oxidation. The strength did not reduce beyond the accumulated exposure time of 20 hr.

Exposure of Mice to a Strong AC Electric Field - An Experimental Study

Twenty-two male mice were exposed to a 60-Hz ac electric field by placing them, in cages, between parallel plates energized to create a field, initially unperturbed, of 4 kV/in. In the course of 10½ months, each animal had an accumulated exposure time of nearly 1500 hours. These animals, and a parallel control group (essentially identically handled but receiving no exposure to electric fields), were repeatedly bred and observed to determine whether there were any effects, harmful or beneficial, as a result of the exposure.