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1.
Article in English | MEDLINE | ID: mdl-36266177

ABSTRACT

OBJECTIVES: To determine the types of products used to treat dry mouth and their perceived effectiveness, the relationship between salivary function and xerostomia symptoms, and whether salivary function predicts response to management strategies. STUDY DESIGN: Cross-sectional study of 87 patients with dry mouth and documented unstimulated whole salivary (UWS) and stimulated whole salivary (SWS) flow rates. Participants completed a questionnaire assessing dry mouth complaints and symptoms and effectiveness of specific dry mouth products. RESULTS: Mean (SD) age was 61.7 (12.9) years including 78 (90%) females. 47 (54%) participants had Sjögren's disease. Oral dryness symptoms (0-10 scale) rated highest with a mean (SD) of 7.2 (2.17); other symptoms scored from 3.4 to 5.1. Lower levels of UWS and SWS were associated with worse dry mouth and difficulty speaking, while lower levels of SWS flow alone were associated with greater difficulty swallowing and a decline in taste. More than half of the participants (55%, n = 48) reported using ≥4 dry mouth products. Participants with normal SWS flow had significantly better responses to lozenges and prescription products. CONCLUSIONS: Patients with dry mouth and normal stimulated flow rates (i.e., residual salivary capacity) respond better to stimulatory products (parasympathomimetic and lozenges). Salivary flow rate assessments may help with recommendations of dry mouth products.


Subject(s)
Sjogren's Syndrome , Xerostomia , Female , Humans , Middle Aged , Male , Patient Satisfaction , Cross-Sectional Studies , Sjogren's Syndrome/complications , Surveys and Questionnaires , Saliva
2.
Langenbecks Arch Surg ; 407(4): 1315-1332, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35307746

ABSTRACT

Since the eruption of the worldwide SARS-CoV-2 pandemic in late 2019/early 2020, multiple elective surgical interventions were postponed. Through pandemic measures, elective operation capacities were reduced in favour of intensive care treatment for critically ill SARS-CoV-2 patients. Although intermittent low-incidence infection rates allowed an increase in elective surgery, surgeons have to include long-term pulmonary and extrapulmonary complications of SARS-CoV-2 infections (especially "Long Covid") in their perioperative management considerations and risk assessment procedures. This review summarizes recent consensus statements and recommendations regarding the timepoint for surgical intervention after SARS-CoV-2 infection released by respective German societies and professional representatives including DGC/BDC (Germany Society of Surgery/Professional Association of German Surgeons e.V.) and DGAI/BDA (Germany Society of Anesthesiology and Intensive Care Medicine/Professional Association of German Anesthesiologists e.V.) within the scope of the recent literature. The current literature reveals that patients with pre- and perioperative SARS-CoV-2 infection have a dramatically deteriorated postoperative outcome. Thereby, perioperative mortality is mainly caused by pulmonary and thromboembolic complications. Notably, perioperative mortality decreases to normal values over time depending on the duration of SARS-CoV-2 infection.


Subject(s)
COVID-19 , Critical Care , Elective Surgical Procedures/adverse effects , Humans , Pandemics , SARS-CoV-2
3.
Chirurg ; 92(11): 1016-1020, 2021 Nov.
Article in German | MEDLINE | ID: mdl-34586429

ABSTRACT

Different perspectives exist among the various specialist disciplines on the treatment of trauma patients with injuries of the urogenital tract. The multidisciplinary consensus guidelines of the World Society of Emergency Surgery (WSES) and the American Association for the Surgery of Trauma (AAST), which appeared in autumn 2019, are summarized in this article. They should constitute an aid to making decisions on the optimal treatment of trauma patients with urogenital injuries.


Subject(s)
Urogenital System/injuries , Humans , United States
4.
Environ Monit Assess ; 192(6): 333, 2020 May 07.
Article in English | MEDLINE | ID: mdl-32383103

ABSTRACT

NIOSH researchers designed a high-sensitivity (HS) cassette to improve the limit of detection of the National Institute for Occupational Safety and Health's (NIOSH) method 5040 and the Airtec near real-time diesel particulate matter (DPM) monitor. This was achieved by reducing the size of the diesel particulate matter deposition spot from 8.0 cm2 (NIOSH method 5040 mining samples) and 7.6 cm2 (Airtec samples) to 0.5 cm2. When compared with the standard cassette, the new high-sensitivity cassette improves the limit of detection of NIOSH method 5040 by approximately five times, and the differences between the elemental carbon results from the HS cassette and the standard three-piece cassette were within statistical error. The limit of detection for Airtec measurements improved by approximately 15 times, and the elemental carbon results with the HS cassette between the Airtec and NIOSH method 5040 were within statistical agreement. When used in the Airtec monitor, the high-sensitivity cassette showed promise for measuring short-duration spot checks of ambient concentrations but was limited when performing some long-term sampling due to the resultant loss of dynamic range. Only up to 7 µg of elemental carbon was collected onto the HS cassette before the increase in pump backpressure caused the flow fluctuations to exceed targeted values by unacceptable levels. The HS cassette shows promise for effective engineering evaluations of control technologies and strategies and near real-time diesel particulate matter measurements for a variety of occupations.


Subject(s)
Environmental Monitoring , Particulate Matter , Vehicle Emissions , Limit of Detection , Particle Size , United States
5.
Phys Med Biol ; 65(1): 01NT01, 2020 01 13.
Article in English | MEDLINE | ID: mdl-31829983

ABSTRACT

The PTW 60023 microSilicon is a new unshielded diode detector for small-field photon dosimetry. It provides improved water equivalence and a slightly larger sensitive region diameter in comparison to previous diode detectors in this range. In this study we evaluated the correction factors relevant to commissioning a CyberKnife System with this detector by Monte Carlo simulation and verified this data by multi-detector measurement comparison. The correction factors required for output factor determination were substantially closer to unity at small field sizes than for previous diode versions (e.g. [Formula: see text] = 0.981 at 5 mm field size which compares with corrections of 5%-6% with other stereotactic diodes). Because of these differences we recommend that corrections to small field output factor measurements generated specifically for the microSilicon detector rather than generic data taken from other diode types should be used with this new detector. For depth-dose measurements the microSilicon is consistent with a microDiamond detector to <1% (global), except at depths <10 mm where the diode gives a significantly lower measurement, by 6%-8% at the surface. For profile measurements, the microSilicon requires negligible corrections except in the low dose region outside the beam, where it underestimates off-axis-ratio (OAR) for small fields and overestimates for large fields. Where this effect is most noticeable at the largest field size and depth (115 mm × 100 mm and 300 mm depth) the microSilicon overestimates OAR by 2.3% (global) in the profile tail. This is consistent with other unshielded diodes.


Subject(s)
Algorithms , Particle Accelerators/instrumentation , Phantoms, Imaging , Radiometry/instrumentation , Radiosurgery/instrumentation , Silicon/chemistry , Humans , Monte Carlo Method , Photons , Radiometry/methods , Radiosurgery/methods , Water/chemistry
6.
Min Eng ; 70(5): 61-68, 2018 May.
Article in English | MEDLINE | ID: mdl-30147149

ABSTRACT

In April 2016, the U.S. Mine Safety and Health Administration (MSHA) began requiring the use of continuous personal dust monitors to monitor and measure respirable mine dust exposures to underground coal miners. Mines are currently using the PDM3700 personal dust monitor to comply with this regulation. After the PDM3700's implementation, mine operators discovered that it interfered with proximity detection systems, thus exposing miners to potential striking and pinning hazards from continuous mining machines. Besides the PDM3700, other electronic devices were also previously reported to interfere with proximity detection systems. MSHA sought the aid of the U.S. National Institute for Occupational Safety and Health (NIOSH) and mining industry stakeholders to determine how the PDM3700 and some other electronic devices and proximity detection systems interact with each other. Accordingly, NIOSH investigated existing standards, developed test protocols, designed experiments and conducted laboratory evaluations. Some interferences were observed to be caused by electromagnetic interference from some electronic devices, including the PDM3700. Results showed that there was no significant interference when the PDM3700, as well as other electronic devices, and the miner-wearable component of the proximity detection system were separated by distances of 15 cm (6 in.) or greater. In the present study, it was found that the PDM3700 and the personal alarm device needed to be at least 15 cm (6 in.) apart in order for them to be used simultaneously and reduce potential interference.

7.
Biomed Res Int ; 2017: 6078498, 2017.
Article in English | MEDLINE | ID: mdl-28856160

ABSTRACT

AIMS/INTRODUCTION: Determining the prevalence of diabetes and its cardiovascular complications and all-cause mortality in older chronic complex patients. MATERIALS AND METHODS: We carried out a multicenter retrospective study and included a randomized sample of 932 CCP people. We assessed the prevalence of diabetes according to World Health Organization criteria. Data included demographics and functional, comorbidity, cognitive, and social assessment. RESULTS: The prevalence of diabetes was 53% and average age 81.16 ± 8.93 years. There were no significant differences in the survival of CCP patients with or without DM, with or without ischaemic cardiopathy, and with or without peripheral vascular disease. The prognostic factors of all-cause mortality in patients with DM were age ≥ 80 years [HR 1.47, 95% CI 1.02-2.13, p 0.038], presence of heart failure [HR 1.73, 95% CI 1.25-2.38, p 0.001], Charlson score [HR 1.20, 95% CI 1.06-1.36, p 0.003], presence of cognitive impairment [HR 1.73, 95% CI 1.24-2.40, p 0.001], and no treatment with statins [HR 1.49, 95% CI 1.08-2.04, p 0.038]. CONCLUSIONS: We found high prevalence of DM among CCP patients and the relative importance of traditional risk factors seemed to wane with advancing age. Recommendations may include relaxing treatment goals, providing family/patient education, and enhanced communication strategies.


Subject(s)
Cardiovascular Diseases/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Heart Failure/epidemiology , Multiple Chronic Conditions/epidemiology , Aged , Aged, 80 and over , Cardiovascular Diseases/etiology , Cardiovascular Diseases/pathology , Comorbidity , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/pathology , Female , Heart Failure/pathology , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors
8.
Phys Med Biol ; 62(3): 1076-1095, 2017 02 07.
Article in English | MEDLINE | ID: mdl-28033110

ABSTRACT

Monte Carlo simulation was used to calculate correction factors for output factor (OF), percentage depth-dose (PDD), and off-axis ratio (OAR) measurements with the CyberKnife M6 System. These include the first such data for the InCise MLC. Simulated detectors include diodes, air-filled microchambers, a synthetic microdiamond detector, and point scintillator. Individual perturbation factors were also evaluated. OF corrections show similar trends to previous studies. With a 5 mm fixed collimator the diode correction to convert a measured OF to the corresponding point dose ratio varies between -6.1% and -3.5% for the diode models evaluated, while in a 7.6 mm × 7.7 mm MLC field these are -4.5% to -1.8%. The corresponding microchamber corrections are +9.9% to +10.7% and +3.5% to +4.0%. The microdiamond corrections have a maximum of -1.4% for the 7.5 mm and 10 mm collimators. The scintillator corrections are <1% in all beams. Measured OF showed uncorrected inter-detector differences >15%, reducing to <3% after correction. PDD corrections at d > d max were <2% for all detectors except IBA Razor where a maximum 4% correction was observed at 300 mm depth. OAR corrections were smaller inside the field than outside. At the beam edge microchamber OAR corrections were up to 15%, mainly caused by density perturbations, which blurs the measured penumbra. With larger beams and depths, PTW and IBA diode corrections outside the beam were up to 20% while the Edge detector needed smaller corrections although these did vary with orientation. These effects are most noticeable for large field size and depth, where they are dominated by fluence and stopping power perturbations. The microdiamond OAR corrections were <3% outside the beam. This paper provides OF corrections that can be used for commissioning new CyberKnife M6 Systems and retrospectively checking estimated corrections used previously. We recommend the PDD and OAR corrections are used to guide detector selection and inform the evaluation of results rather than to explicitly correct measurements.


Subject(s)
Radiation Dosage , Radiosurgery/methods , Models, Theoretical , Monte Carlo Method , Radiation Dosimeters , Radiosurgery/instrumentation , Radiosurgery/standards
9.
Pediatr Obes ; 12(5): 388-397, 2017 10.
Article in English | MEDLINE | ID: mdl-27237983

ABSTRACT

BACKGROUND: There is an increasing adolescent population with severe obesity with impairments in social and romantic relationships that are seeking clinical weight management, including weight loss surgery (WLS). OBJECTIVE: To document romantic, sexual and sexual risk behaviours in a clinical sample of adolescent females with severe obesity (BMI > 40 kg/m2 ) compared to those of healthy weight (HW). METHODS: This multi-site study-an ancillary to a prospective longitudinal observational study documenting health in adolescents having WLS-presents pre-operative/baseline data from 108 females undergoing WLS, 68 severely obese seeking lifestyle intervention and 118 of HW. Romantic and sexual risk behaviour and birth control information sources were assessed using the Sexual Activities and Attitudes Questionnaire (SAAQ). RESULTS: Severely obese females reported engaging in fewer romantic and sexual behaviours compared to HW. Similar to HW, a subgroup (25%) of severely females were engaging in higher rates of sexual risk behaviours and reported pregnancies and sexually transmitted infections (STIs). A considerable number (28-44%) reported receiving no birth control information from physicians. CONCLUSIONS: Discussion topics with the adolescent patient should extend beyond reproductive health needs (e.g. contraception, unintended pregnancies) to include guidance around navigating romantic and sexual health behaviours that are precursors to these outcomes.


Subject(s)
Adolescent Behavior/psychology , Bariatric Surgery/psychology , Obesity, Morbid/psychology , Pediatric Obesity/psychology , Risk-Taking , Sexual Behavior/psychology , Adolescent , Cohort Studies , Contraception/statistics & numerical data , Female , Humans , Longitudinal Studies , Obesity, Morbid/surgery , Pediatric Obesity/surgery , Prospective Studies , Sexually Transmitted Diseases/epidemiology , Surveys and Questionnaires
10.
Min Eng ; 68(8): 50-58, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27524838

ABSTRACT

Significant strides have been made in optimizing the design of filtration and pressurization systems used on the enclosed cabs of mobile mining equipment to reduce respirable dust and provide the best air quality to the equipment operators. Considering all of the advances made in this area, one aspect that still needed to be evaluated was a comparison of the efficiencies of the different filters used in these systems. As high-efficiency particulate arrestance (HEPA) filters provide the highest filtering efficiency, the general assumption would be that they would also provide the greatest level of protection to workers. Researchers for the U.S. National Institute for Occupational Safety and Health (NIOSH) speculated, based upon a previous laboratory study, that filters with minimum efficiency reporting value, or MERV rating, of 16 may be a more appropriate choice than HEPA filters in most cases for the mining industry. A study was therefore performed comparing HEPA and MERV 16 filters on two kinds of underground limestone mining equipment, a roof bolter and a face drill, to evaluate this theory. Testing showed that, at the 95-percent confidence level, there was no statistical difference between the efficiencies of the two types of filters on the two kinds of mining equipment. As the MERV 16 filters were less restrictive, provided greater airflow and cab pressurization, cost less and required less-frequent replacement than the HEPA filters, the MERV 16 filters were concluded to be the optimal choice for both the roof bolter and the face drill in this comparative-analysis case study. Another key finding of this study is the substantial improvement in the effectiveness of filtration and pressurization systems when using a final filter design.

11.
Rev Neurol ; 62(9): 385-95, 2016 May 01.
Article in Spanish | MEDLINE | ID: mdl-27113062

ABSTRACT

AIM: To determine the population incidence of intracerebral haemorrhage and its preventable incidence, associated risk factors and prognosis of death and disability. SUBJECTS AND METHODS: We examined a sample of 240 consecutive patients with a first episode of intracerebral haemorrhage between 1st April 2006 and 30th June 2015. The main variables are: NIHSS scale, comorbidity, pharmacological information, Barthel index, Rankin scale, time within therapeutic window, prognosis and destination on hospital discharge. The 'unnecessarily premature and sanitarily avoidable mortality' (MIPSE) classification was applied to define the cases as 'preventable incidence'. RESULTS: The rate of population incidence of haemorrhagic cerebrovascular disease was 23.5 cases per 100,000 inhabitants/year; an exponential increase occurred from the age of 55 years in males and 75 years in females. The rate ratio was 0.682. The preventable incidence would account for 66.6% of all the cases in those under 75 years of age and 22.7% in those aged 75 or over. The chances of survival and functional autonomy were significantly lower in females, and age, anticoagulant treatment, the presence of polymedication and treatment with serotonin reuptake inhibitor antidepressants were factors that were independent of the prognosis. CONCLUSIONS: The incidence of haemorrhagic cerebrovascular disease does not appear to be modified within the period, but just the opposite occurs with the factors associated according to sex and age. According to the MIPSE classification, the preventability of haemorrhagic cerebrovascular disease could be as high as 36%.


TITLE: Incidencia y evitabilidad de los ictus hemorragicos. Resultados del registro Ebrictus.Objetivo. Conocer la incidencia poblacional de la hemorragia intracerebral y su incidencia evitable, factores de riesgo asociados y pronostico de muerte y discapacidad. Sujetos y metodos. Muestra de 240 pacientes consecutivos con un primer episodio de hemorragia intracerebral entre el 1 de abril de 2006 y el 30 de junio de 2015. Las variables principales son: escala NIHSS, comorbilidad, informacion farmacologica, indice de Barthel, escala de Rankin, tiempo en rango terapeutico, pronostico y destino al alta hospitalaria. Se aplico la clasificacion 'mortalidad innecesariamente prematura y sanitariamente evitable' (MIPSE) para definir los casos como 'incidencia evitable'. Resultados. La tasa de incidencia poblacional de enfermedad cerebrovascular hemorragica fue de 23,5 casos por 100.000 habitantes/año; se produjo un incremento exponencial a partir de los 55 años en hombres y 75 años en mujeres. La razon de tasas fue de 0,682. La incidencia evitable significaria el 66,6% de todos los casos en los menores de 75 años y el 22,7% en aquellos con 75 o mas años. La probabilidad de supervivencia y la autonomia funcional fueron significativamente inferiores en las mujeres, y la edad, el tratamiento anticoagulante, la presencia de polimedicacion y el tratamiento con antidepresivos inhibidores de la recaptacion de serotonina fueron factores independientes del pronostico. Conclusiones. No parece que se modifique la incidencia de enfermedad cerebrovascular hemorragica en el periodo, pero si los factores asociados segun sexo y edad. Segun la clasificacion MIPSE, la evitabilidad de la enfermedad cerebrovascular hemorragica seria de hasta un 36%.


Subject(s)
Intracranial Hemorrhages/epidemiology , Intracranial Hemorrhages/prevention & control , Stroke/epidemiology , Stroke/prevention & control , Aged , Anticoagulants/therapeutic use , Female , Humans , Incidence , Male , Middle Aged , Registries , Risk Factors
12.
Urologe A ; 55(4): 514-9, 2016 Apr.
Article in German | MEDLINE | ID: mdl-26450093

ABSTRACT

BACKGROUND: Urinary tract infections (UTI) are among the most common reasons for antibiotic prescriptions. Due to increasing resistance rates, antibiotic therapy should be targeted and based on evidence-based recommendations. Test results and recommendations by medical laboratories have a relevant impact on the choice of antibiotics. The extent to which medical laboratories consider antibiotics recommended by evidence-based treatment guidelines in microbiological testing is unclear. OBJECTIVES: The aim of the present study is to assess whether guideline recommendations for antibiotic therapy of UTI are taken into account by medical laboratories in northern Germany. MATERIALS AND METHODS: A standardized and piloted questionnaire was used in our telephone survey. All microbiological laboratories in northern Germany (Hamburg, Bremen, Lower Saxony, Schleswig-Holstein, and Mecklenburg-Western Pomerania; n = 82) were asked about their standards in diagnosing and microbiological testing of urine cultures. RESULTS: A total of 71 of the 82 contacted laboratories perform microbiological tests, whereby 40 of these participated (56 %). Most of the laboratories (43 %) routinely perform microbiological testing when bacterial counts were ≥ 10(4) colony forming units per ml (CFU/ml), 15 % ≥ 10(5) CFU/ml, 17 % ≥ 10(3) CFU/ml, and 8 % ≥ 10(2) CFU/ml. Antibiotic testing includes ciprofloxacin (95 %), cotrimoxazole (87.5 %), trimethoprim (57 %), fosfomycin (85 %), and nitrofurantoin (72 %). CONCLUSIONS: The diagnostic threshold recommended in evidence-based guidelines (10(3) CFU/ml) is used only by a few laboratories. Antibiotics recommended as a first line therapy are only partly taken into account in microbiological testing. This variance in different diagnostic thresholds and microbiological testing is a barrier to guideline implementation.


Subject(s)
Drug Resistance, Bacterial , Guideline Adherence/statistics & numerical data , Microbial Sensitivity Tests/standards , Practice Guidelines as Topic , Urinary Tract Infections/microbiology , Urology/standards , Anti-Bacterial Agents/therapeutic use , Bacterial Typing Techniques/standards , Bacterial Typing Techniques/statistics & numerical data , Female , Germany/epidemiology , Humans , Male , Microbial Sensitivity Tests/statistics & numerical data , Urinary Tract Infections/diagnosis , Urinary Tract Infections/drug therapy
13.
Trans Soc Min Metall Explor Inc ; 340: 38-47, 2016 Mar.
Article in English | MEDLINE | ID: mdl-28596699

ABSTRACT

The Office of Mine Safety and Health Research of the U.S. National Institute for Occupational Safety and Health (NIOSH OMSHR) conducted laboratory testing of a self-tramming, remotely controlled mobile Dry Scrubber (DS) that J.H. Fletcher and Co. developed under a contract with NIOSH OMSHR to reduce the exposure of miners to airborne dust. The scrubber was found to average greater than 95 percent dust removal efficiency with disposable filters, and 88 and 90 percent, respectively, with optional washable filters in their prewash and post-wash test conditions. Although the washable filters can be reused, washing them generated personal and downstream respirable dust concentrations of 1.2 and 8.3 mg/m3, respectively, for a 10-min washing period. The scrubber's velocity-pressure-regulated variable-frequency-drive fan maintained relatively consistent airflow near the targeted 1.42 and 4.25 m3/s (3,000 and 9,000 ft3/min) airflow rates during most of the laboratory dust testing until reaching its maximum 60-Hz fan motor frequency or horsepower rating at 2,610 Pa (10.5 in. w.g.) of filter differential pressure and 3.97 m3/s (8,420 ft3/min) of scrubber airflow quantity. Laboratory sound level measurements of the scrubber showed that the outlet side of the scrubber was noisier, and the loaded filters increased sound levels compared with clean filters at the same airflow quantities. With loaded filters, the scrubber reached a 90 dB(A) sound level at 2.83 m3/s (6,000 ft3/min) of scrubber airflow, indicating that miners should not be overexposed in relation to MSHA's permissible exposure level - under Title 30 Code of Federal Regulations Part 62.101- of 90 dB(A) at or below this airflow quantity. The scrubber's washable filters were not used during field-testing because of their lower respirable dust removal efficiency and the airborne dust generated by filter washing. Field-testing the scrubber with disposable filters at two underground coal mine sections showed that it could clean a portion of the section return air and provide dust reduction of about 50 percent at the face area downstream of the continuous-miner operation.

14.
Min Eng ; 67(12): 42-48, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26834293

ABSTRACT

The National Institute for Occupational Safety and Health has observed that many control rooms and operator compartments in the U.S. mining industry do not have filtration systems capable of maintaining low dust concentrations in these areas. In this study at a mineral processing plant, to reduce respirable dust concentrations in a control room that had no cleaning system for intake air, a filtration and pressurization system originally designed for enclosed cabs was modified and installed. This system was composed of two filtering units: one to filter outside air and one to filter and recirculate the air inside the control room. Eighty-seven percent of submicrometer particles were reduced by the system under static conditions. This means that greater than 87 percent of respirable dust particles should be reduced as the particle-size distribution of respirable dust particles is greater than that of submicrometer particles, and filtration systems usually are more efficient in capturing the larger particles. A positive pressure near 0.02 inches of water gauge was produced, which is an important component of an effective system and minimizes the entry of particles, such as dust, into the room. The intake airflow was around 118 cfm, greater than the airflow suggested by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) for acceptable indoor air quality. After one year, the loading of the filter caused the airflow to decrease to 80 cfm, which still produces acceptable indoor air quality. Due to the loading of the filters, the reduction efficiency for submicrometer particles under static conditions increased to 94 percent from 87 percent.

15.
Min Eng ; 66(2): 45-52, 2014 Feb.
Article in English | MEDLINE | ID: mdl-26236044

ABSTRACT

An effective technique to minimize miners' respirable dust and diesel exposure on mobile mining equipment is to place mine operators in enclosed cabs with designed filtration and pressurization systems. Many factors affect the performance of these enclosed cab systems, and one of the most significant factors is the effectiveness of the filtration system. High-efficiency particulate air (HEPA)-type filters are typically used because they are highly efficient at capturing all types and sizes of particles, including those in the submicron range such as diesel particulate matter (DPM). However, in laboratory tests, minimum efficiency reporting value (MERV) 16 filters have proven to be highly efficient for capturing DPM and respirable dust. Also, MERV 16 filters can be less restrictive to cab airflow and less expensive than HEPA filters. To verify their effectiveness in the field, MERV 16 filters were used in the enclosed cab filtration system on a face drill and roof bolting mining machine and tested at an underground limestone mine. Test results showed that DPM and respirable dust concentrations were reduced by more than 90% when the cabs were properly sealed. However, when the cab door was opened periodically throughout the shift, the reduction efficiency of the MERV 16 filters was reduced to 80% on average.

16.
Min Eng ; 66(10): 43, 2014 Oct.
Article in English | MEDLINE | ID: mdl-26190862

ABSTRACT

The Office of Mine Safety and Health Research (OMSHR) investigated ways to increase mine airflow to underground metal/nonmetal (M/NM) mine working areas to improve miners' health and safety. One of those areas is controlled recirculation. Because the quantity of mine air often cannot be increased, reusing part of the ventilating air can be an effective alternative, if implemented properly, until the capacity of the present system is improved. The additional airflow can be used to provide effective dilution of contaminants and higher flow velocities in the underground mine environment. Most applications of controlled recirculation involve taking a portion of the return air and passing it back into the intake to increase the air volume delivered to the desired work areas. OMSHR investigated a Nevada gold mine where shaft rehabilitation was in progress and one of the two main fans was shut down to allow reduced air velocity for safe shaft work. Underground booster fan operating pressures were kept constant to maintain airflow to work areas, inducing controlled recirculation in one work zone. Investigation into system behavior and the effects of recirculation on the working area during times of reduced primary ventilation system airflow would provide additional information on implementation of controlled recirculation into the system and how these events affect M/NM ventilation systems. The National Institute for Occupational Safety and Health monitored the ventilation district when both main fans were operating and another scenario with one of the units turned off for maintenance. Airflow and contaminants were measured to determine the exposure effects of induced recirculation on miner health. Surveys showed that 19% controlled recirculation created no change in the overall district airflow distribution and a small reduction in district fresh air intake. Total dust levels increased only modestly and respirable dust levels were also low. Diesel particulate matter (DPM) levels showed a high increase in district intake mass flow, but minor increases in exposure levels related to the recirculation percentage. Utilization of DPM mass flow rates allows input into ventilation modeling programs to better understand and plan for ventilation changes and district recirculation effects on miners' health.

17.
J Occup Environ Hyg ; 10(12): 716-22, 2013.
Article in English | MEDLINE | ID: mdl-24195538

ABSTRACT

The standard method for determining diesel particulate matter (DPM) exposures in underground metal/nonmetal mines provides the average exposure concentration for an entire working shift, and it can take weeks to obtain results. This approach is problematic because, although it reports that an overexposure has occurred, it fails to provide critical information about cause or prevention. Conversely, real-time measurement would provide miners with timely information to identify the major factors contributing to overexposures and would allow engineering controls to be deployed immediately. Due to these potential benefits, the National Institute for Occupational Safety and Health (NIOSH) developed a wearable instrument that measures real-time elemental carbon (EC) concentrations (EC is a DPM surrogate) via laser extinction. This instrument was later constructed into a commercial version (Airtec). This article evaluates the Airtec's performance in several underground metal/nonmetal mines by comparing it to the standard method for determining DPM exposures (NIOSH method 5040). The instrument was found to meet the NIOSH accuracy criteria and to show no statistical difference from NIOSH method 5040 results. In addition, the instrument's measurements were found to be unaffected by dust and humidity.


Subject(s)
Environmental Monitoring/methods , Mining , Particulate Matter/analysis , Vehicle Emissions/analysis , Environmental Monitoring/instrumentation , Humans , National Institute for Occupational Safety and Health, U.S. , Occupational Exposure/analysis , Occupational Exposure/prevention & control , Time Factors , United States
18.
Oncogene ; 32(10): 1252-65, 2013 Mar 07.
Article in English | MEDLINE | ID: mdl-22580601

ABSTRACT

Tumour-derived mutant p53 proteins promote invasion, in part, by enhancing Rab coupling protein (RCP)-dependent receptor recycling. Here we identified MET as an RCP-binding protein and showed that mutant p53 promoted MET recycling. Mutant p53-expressing cells were more sensitive to hepatocyte growth factor, the ligand for MET, leading to enhanced MET signalling, invasion and cell scattering that was dependent on both MET and RCP. In cells expressing the p53 family member TAp63, inhibition of TAp63 also lead to cell scattering and MET-dependent invasion. However, in cells that express very low levels of TAp63, the ability of mutant p53 to promote MET-dependent cell scattering was independent of TAp63. Taken together, our data show that mutant p53 can enhance MET signalling to promote cell scattering and invasion through both TAp63-dependent and -independent mechanisms. MET has a predominant role in metastatic progression and the identification of mechanisms through which mutations in p53 can drive MET signalling may help to identify and direct therapy.


Subject(s)
Mutation , Proto-Oncogene Proteins c-met/genetics , Proto-Oncogene Proteins c-met/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Animals , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Movement , Colonic Neoplasms/genetics , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , HCT116 Cells , HT29 Cells , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Neoplasm Invasiveness , Phosphorylation , Signal Transduction , Transcription Factors/metabolism , Transfection , Tumor Suppressor Proteins/metabolism
19.
Oncogene ; 32(24): 2992-3000, 2013 Jun 13.
Article in English | MEDLINE | ID: mdl-22797073

ABSTRACT

Loss of p53 function is a critical event during tumorigenesis, with half of all cancers harboring mutations within the TP53 gene. Such events frequently result in the expression of a mutated p53 protein with gain-of-function properties that drive invasion and metastasis. Here, we show that the expression of miR-155 was up-regulated by mutant p53 to drive invasion. The miR-155 host gene was directly repressed by p63, providing the molecular basis for mutant p53 to drive miR-155 expression. Significant overlap was observed between miR-155 targets and the molecular profile of mutant p53-expressing breast tumors in vivo. A search for cancer-related target genes of miR-155 revealed ZNF652, a novel zinc-finger transcriptional repressor. ZNF652 directly repressed key drivers of invasion and metastasis, such as TGFB1, TGFB2, TGFBR2, EGFR, SMAD2 and VIM. Furthermore, silencing of ZNF652 in epithelial cancer cell lines promoted invasion into matrigel. Importantly, loss of ZNF652 expression in primary breast tumors was significantly correlated with increased local invasion and defined a population of breast cancer patients with metastatic tumors. Collectively, these findings suggest that miR-155 targeted therapies may provide an attractive approach to treat mutant p53-expressing tumors.


Subject(s)
Breast Neoplasms/genetics , Breast Neoplasms/pathology , MicroRNAs/genetics , Mutation , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Up-Regulation/genetics , Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Movement/genetics , DNA-Binding Proteins/metabolism , Epithelial Cells/metabolism , Epithelial Cells/pathology , Epithelial-Mesenchymal Transition/genetics , Gene Regulatory Networks , Humans , Membrane Proteins/metabolism , Mutant Proteins/genetics , Mutant Proteins/metabolism , Neoplasm Invasiveness , Signal Transduction/genetics
20.
Min Eng ; 65(10): 42-49, 2013 Oct.
Article in English | MEDLINE | ID: mdl-26190861

ABSTRACT

There is a need for direct tailpipe sampling of diesel vehicles in mines in order to determine the effects of an emissions-based maintenance program, evaluate control technologies such as diesel particulate filters and identify the worst diesel particulate matter (DPM) emitters in a fleet of vehicles. Therefore, this study examined the performance of three portable instruments: a personal dust monitor (PDM) manufactured by Thermo Scientific, a prototype elemental carbon monitor (Airtec) manufactured by FLIR and a prototype AE91 instrument from Magee Scientific. These instruments were evaluated on the basis of their ability to provide direct reading tailpipe analysis for DPM. It was determined that the average bias of the tailpipe results from the PDM and the Airtec were 3±12% and 4±20%, respectively, when compared to the standard method of determining tailpipe particulate concentrations from a diluted exhaust. It was also determined that the AE91 instrument correlated with the standard method.

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