Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FOG”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1993

How to clear fogged lenses within the arthroscopic camera bag.

Arthroscopic camera bags are extremely practical because they allow multiple procedures to be performed in the same day. This is especially true for small community hospitals where equipment is limited. Unfortunately, the plastic creates a greenhouse effect, allowing any moisture that is present to condense and fog the camera and scope. By using sponges placed inside the camera bag to wipe the optical lenses, the surgeon can improve visualization during an arthroscopic procedure if fogging becomes a problem.

Arthroscopes↗
PubMed1977

Determination of indole and 3-methylindole in plasma and rumen fluid from cattle with fog fever or after L-tryptophan administration.

A modified gas liquid chromatography method has been developed to analyse the concentrations of indole and 3-methylindole in samples of plasma and rumen fluid from four cows with fog fever together with four control animals and from two cattle given L-tryptophan orally. Satisfactory recoveries of the metabolites were obtained in test samples examined by the gas liquid chromatography procedure and increased levels were found in rumen fluid after tryptophan administration. Absence of abnormal concentrations of the toxic metabolite 3-methylindole in samples from field cases of fog fever was not considered to rule out the metabolite as a possible cause of the disease in view of the rapid restoration of 3-methylindole to normal levels by the second day after loading with L-tryptophan.

Animals↗
PubMed1996

Sensitive method for the determination of different S(IV) species in cloud and fog water.

Suppressed ion chromatography has been applied to the determination of S(IV) species in cloud and fog water in the range 0.012-2.4 mg S(IV)-S/L. The samples have been preserved prior to storage and S(IV) species have been determined as hydroxy methanesulfonate (HMS) together with the low molecular weight carboxylic acid anions, formate and acetate. Samples have been divided and treated differently such that total S(IV) as well as the non-oxidizable fraction of S(IV) (as given by the reactivity with H(2)O(2), added in surplus) could be determined. The difference between the two corresponds to the S(IV) fraction subjected to oxididation, which is of paramount interest in cloud and fogwater chemistry.

Journal Article↗
PubMed2003

Report of fogging effect on fast FLAIR magnetic resonance images of cerebral infarctions.

We report a case of multiple small, presumably iatrogenic, cortical infarctions detected incidentally on magnetic resonance imaging (MRI) 5 days after preoperative cerebral angiography but not apparent 12 days after the angiography on noncontrast MRI including a fast fluid-attenuated inversion recovery (FLAIR) sequence. However, the lesions showed marked contrast enhancement with gadolinium on postcontrast T1-weighted images. Cortical laminar necrosis was observed on MRI 35 days after the initial angiographic study. This case shows that the MRI fogging effect may prevent detection of small cortical infarctions in the subacute stage even on fast FLAIR sequences. Postcontrast images should be studied to reduce diagnostic errors associated with this effect.

Aged↗
PubMed2005

Comparative field study on precipitation, throughfall, stemflow, fog water, and atmospheric aerosol and gases at urban and rural sites in Japan.

Precipitation collected by a wet-only sampler (WP), precipitation collected by a filtering-type bulk sampler (BP), throughfall (TF), stemflow (SF), fog water (FW), and atmospheric aerosol and gases were collected at two sites with different site classifications: an urban site (Mt. Rokko) and a rural site (Mt. Awaga) to investigate canopy-atmosphere interactions and to study the chemistry of precipitation in forested areas located in different atmospheric conditions. Compared to those at the rural site, the monthly volume-weighted pH values at the urban site were not significantly (p>0.05) different for WP, higher (p<0.05) for BP, not significantly (p> 0.05) different for TF, lower (p<0.01) for SF, and lower (p<0.01) for FW. The order of mean pH values at the urban site was FW<SF<WP<TF<BP. In contrast, the order at the rural site was FW<SF<BP<WP<TF. Concentrations of chemical species at the urban site were higher than those at the rural site in all samples and all chemical species. In particular, higher NO(3)(-) concentrations at the urban site were observed in all samples. The amount of dry deposition on leaves at the urban site was approximately 1.17 times larger than that at the rural site. The monthly net TF (=TF-BP) in autumn seemed to be larger than that in summer; this trend was remarkable in K(+). The monthly NO(3)(-) deposition in the net TF was larger at the urban site than at other parameters and at the rural site. The concentrations of chemical species in aerosol and gases that were measured near the central part of Kobe City were ca. 3.4 times higher than those in the rural area. Mt. Rokko borders the central part of the city, which caused the concentrations at Mt. Rokko to be higher than those at Mt. Awaga. The deposition amounts at Mt. Rokko were larger than those at Mt. Awaga, which probably can be attributed to the higher concentrations of chemical species in atmospheric aerosol and gases.

Aerosols↗
PubMed2000

A syndrome of tricuspid atresia in mice with a targeted mutation of the gene encoding Fog-2.

Tricuspid atresia (TA) is a common form of congenital heart disease, accounting for 1-3% of congenital cardiac disorders. TA is characterized by the congenital agenesis of the tricuspid valve connecting the right atrium to the right ventricle and both an atrial septal defect (ASD) and a ventricular septal defect (VSD). Some patients also have pulmonic stenosis, persistence of a left-sided superior vena cava or transposition of the great arteries. Most cases of TA are sporadic, but familial occurrences with disease in multiple siblings have been reported. Gata4 is a zinc-finger transcription factor with a role in early cardiac development. Gata4-deficient mice fail to form a ventral heart tube and die of circulatory failure at embryonic day (E) 8.5 (refs 6,7). Zfpm2 (also known as Fog-2) is a multi-zinc-finger protein that is co-expressed with Gata4 in the developing heart beginning at E8.5 (refs 8-10). Zfpm2 interacts specifically with the N-terminal zinc finger of Gata4 and represses Gata4-dependent transcription. Here we use targeted mutagenesis to explore the role of Zfpm2 in normal cardiac development. Zfpm2-deficient mice died of congestive heart failure at E13 with a syndrome of tricuspid atresia that includes an absent tricuspid valve, a large ASD, a VSD, an elongated left ventricular outflow tract, rightward displacement of the aortic valve and pulmonic stenosis. These mice also display hypoplasia of the compact zone of the left ventricle. Our findings indicate the importance of Zfpm2 in the normal looping and septation of the heart and suggest a genetic basis for the syndrome of tricuspid atresia.

Animals↗
PubMed2001

Evaluation of biological and chemical insecticide mixture against Aedes aegypti larvae and adults by thermal fogging in Singapore.

To improve the operational efficiency of dengue vector control in Singapore, larvicide and adulticide were applied together by thermal fog generator (Agrofog AF40). The mixture consisted of Bacillus thuringiensis var. israelensis (Vectobac 12 AS) as biological larvicide at 1.5 L/ha and pirimiphos-methyl (Actellic 50 EC) as adulticide at 100 g ai/ha, diluted 10-fold with water. Aerosol of this mixture was evaluated against the mosquito Aedes aegypti (L.) (Diptera: Culicidae) in bioassays using cages of 10 adult females exposed at heights of 0.3-2.4 m and distances of 3-12 m from the hand-held generator. Cups containing 200 mL water were treated at ground level by exposure to the aerosol application at the same distances from the generator. Subsequent larval bioassays on days 1, 7, 14, 21 and 28 post-spray involved exposing 20 larvae/cup for 48 h. Droplets had VMD 57 microm and female mosquitoes were killed by 2 s exposure to the aerosol at 3 m. We obtained 92-100% mortality of the adult mosquitoes and 100% control of larvae at 3 m distance, but only 10-13% mortality at 12 m from the fogger. In treated cups, larvae showed high mortality (92%) when exposed for 48 h even 1 month post-treatment. Results demonstrate the practical advantage of using this mixture of Vectobac 12AS and Actellic 50 EC for simultaneous control of Aedes adults and larvae, with prolonged larvicidal efficacy in treated containers.

Aedes↗
PubMed2003

Phase I clinical study of infusional 5-fluorouracil with oxaliplatin and gemcitabine (FOG regimen) in patients with solid tumors.

BACKGROUND: The aim of this study was to determine the maximum tolerated dose, recommended phase II dose (RPTD) and toxicities of the FOG regimen (infusional 5-fluorouracil, oxaliplatin, gemcitabine). PATIENTS AND METHODS: Patients with advanced solid tumors were treated in an accelerated titration scheme. 5-Fluorouracil was administered intravenously at 200 mg/m(2)/day for 14 days and repeated every 21 days (one cycle). Gemcitabine was administered on days 1 and 8 over 30 min at 450-650 mg/m(2). Oxaliplatin was administered on day 1 over 2 h at 85-130 mg/m(2). For cycles 1, 3 and beyond, gemcitabine followed oxaliplatin; for cycle 2, gemcitabine preceded oxaliplatin. RESULTS: Forty-five and 39 patients were assessable for toxicity and response, respectively. Cycle 1 dose-limiting toxicities (DLT) included neutropenia, thrombocytopenia and diarrhea. No DLT was observed in cycle 1 at the first four dose levels (DL). At DL-5, two of four (50%) patients experienced DLT in cycle 1. Expanding DL-4, nine of 26 (35%) patients experienced DLT in cycle 1. Because recurrent grade 3 toxicities were observed in three of six (50%) patients at DL-3, DL-2 was considered the RPTD. At the RPTD, three patients had a partial response (response rate 23%). CONCLUSIONS: The RPTD for the 5-fluorouracil-oxaliplatin-gemcitabine combination is 200/100/450 mg/m(2). This novel regimen has demonstrated activity in advanced solid tumors and merits further investigation.

Adult↗
PubMedDate not supplied

"Fogging effect" in MR of cerebral infarct.

In a case of cerebral infarction the lesions were isointense to slightly hyperintense in the T2-weighted MR images obtained approximately 2 weeks after the onset. Earlier (1 week after onset), they had been markedly hyperintense. The probably mechanisms behind this phenomenon, referred to as "MR fogging" are discussed.

Aged↗
PubMed2006

Blue quantum fog: chiral condensation in quantum helimagnets.

It is shown that a condensation transition involving a chiral order parameter can occur in itinerant helimagnets, in analogy to the transition between the isotropic phase and the phase known as blue fog or blue phase III in cholesteric liquid crystals. It is proposed that such a transition is the explanation for recent neutron scattering results in MnSi. Predictions are made that will allow for experimental tests of this proposal.

Journal Article↗
PubMed1992

An evaluation of the effect of processing conditions on mammographic film contrast, fog levels and speed.

While it is well established that extended development times and temperatures will increase mammographic film contrast and speed (1), little work has been done to date in extending this work to encompass all common screen-film types and to study the effect of processing chemistry variations on contrast speed results. This paper reports on four locally available mammographic films which, after exposure in conditions that closely simulate clinical conditions, have been developed with four different development chemicals as a function of development temperature and time. Three development times were used (23, 32 and 42 seconds) in combination with four development temperatures (32, 34, 36 and 38 degrees). The results support the previously published result of increased speed and contrast with extending development time and temperature. It was further found that, for some film types, the film contrast varied significantly over film density when developed with extended processing. Other film types, however, maintained high contrasts over large film density ranges. In some cases the increased contrast was accompanied by elevated film fog levels. The development of mammographic films in non recommended chemistries produced varying results, mostly detrimental, which demonstrated that selection of development chemistry as well as optimal development times and temperatures, is critical for good film performance.

Absorptiometry, Photon↗
PubMed1984

Overflow movements and behavior problems: scoring and using a modification of Fogs' test.

This study attempted to produce a simple, scorable test of neurological function and to see whether, in the absence of obvious central nervous system disease, the neurological impairments so defined were related to psychiatric disorders. 138 children aged between seven and 11 years from four schools undertook a standardised test based on the Fogs' test. Those who performed poorly on the test had a higher frequency of behaviour problems, motor inco-ordination and adverse perinatal events. Children with any kind of behaviour problem had more difficulty with the test than those without, but hyperactive children did worse than antisocial children. The strength of the statistical association between behaviour problems and functional neurological impairment varied with the social circumstances of the children. Neurological impairment was found more frequently among behaviour-problem children from suburban schools than those from inner-city schools. It appears that a degree of dysfunction lying between brain damage and normal variation places children at higher risk for the development of behaviour problems. Such dysfunction, together with psychosocial disadvantage, may be important aetiological factors in behaviour disorders during childhood.

Attention Deficit Disorder with Hyperactivity↗
PubMed1993

Aqueous-phase photochemical formation of peroxides in authentic cloud and fog waters.

Gas-to-drop partitioning of hydrogen peroxide and its precursor, the hydroperoxyl radical (HO2.), has been considered the predominant or sole source of hydrogen peroxide in atmospheric water drops. However, atmospheric water can absorb solar ultraviolet radiation, which initiates the photoformation of peroxides (primarily hydrogen peroxide). Measurements of peroxide photoformation rates in authentic atmospheric water samples demonstrate that aqueous-phase photochemical reactions are a significant, and in some cases dominant, source of hydrogen peroxide to cloud and fog drops. This additional source could significantly change the current understanding, and hence, the models, of sulfuric acid deposition because hydrogen peroxide is the limiting reagent in the dominant pathway for the oxidation of sulfur dioxide to sulfuric acid in the troposphere over eastern North America.

Atmosphere↗
PubMed1991

Lack of bronchoconstrictor response to sulfuric acid aerosols and fogs.

Sulfuric acid (H2SO4) is the most common acid air pollutant in the United States and is thought to have adverse respiratory effects. Sulfuric acid exists in polluted air as a dissolved solute in both small (haze) and large (fog) particles. Previous work in our laboratory has failed to demonstrate bronchoconstriction after near ambient, large-particle H2SO4 exposure in subjects with asthma. However, other investigators have found slight but significant changes in lung function following inhalation of small-particle or small-particle, low-relative-humidity (RH) H2SO4 aerosols, leading us to hypothesize that particle size and/or RH may be important variables in acid aerosol exposure. We initially studied the effects of resting inhalation of large-particle (volume median diameter, VMD, approximately equal to 6 microns) and small-particle (VMD approximately equal to 0.4 microns) aerosols with an H2SO4 concentration of 3 mg/m3 through a mouthpiece and found no effect on specific airway resistance (SRaw) or symptom scores. In a second mouthpiece study designed to compare high-RH (100%), large-particle (VMD approximately equal to 6 microns) and low-RH (less than 10%), small-particle (VMD approximately equal to 0.3 microns) aerosols with an H2SO4 concentration of 3 mg/m3, we again found no effect of either aerosol. We then examined the effects of small-particle aerosols inhaled in dry air during moderate exercise. Although breathing low-RH air during exercise provoked increases in SRaw in almost all subjects, this could not be attributed to H2SO4 since low-RH saline aerosol produced a similar result.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

Reassessment of the lethal London fog of 1952: novel indicators of acute and chronic consequences of acute exposure to air pollution.

This article develops and assesses novel indicators of respiratory and other morbidity and mortality following London's lethal smog in the winter of 1952. Public health insurance claims, hospital admission rates for cardiac and respiratory disease, pneumonia cases, mortality records, influenza reports, temperature, and air pollutant concentrations are analyzed for December-February 1952-1953 and compared with those for the previous year or years. Mortality rates for the smog episode from December 1952 to February 1953 were 50-300% higher than the previous year. Claims that the smog only elevated health risks during and immediately following the peak fog 5-9 December 1952 and that an influenza epidemic accounted fully for persisting mortality increases in the first 2 months of 1953 are rejected. We estimate about 12,000 excess deaths occurred from December 1952 through February 1953 because of acute and persisting effects of the 1952 London smog. Pollution levels during the London smog were 5-19 times above current regulatory standards and guidelines and approximate current levels in some rapidly developing regions. Ambient pollution in many regions poses serious risks to public health.

Acute Disease↗
PubMed1989

Acid fog: effects on respiratory function and symptoms in healthy and asthmatic volunteers.

Acidic air pollutants generally are dissolved in water droplets. Mean droplet diameter may range from more than 10 microns in dense fog to less than 1 micron at low relative humidity. Droplet size influences the deposition of inhaled acid within the respiratory tract and thus may influence toxicity. To help assess health risks from acid pollution, we performed controlled exposures of normal and asthmatic volunteers to sulfuric acid aerosols at nominal concentrations of 0 (control), 500, 1000, and 2000 micrograms/m3. Exposures lasted 1 hr with intermittent heavy exercise. Response was assessed by lung function tests and symptom questionnaires. Under foggy conditions (mean droplet size 10 microns, temperature 50 degrees F), no marked effects on lung function were found. However, both normal and asthmatic subjects showed statistically significant dose-related increases in respiratory symptoms. In a separate study, normal subjects exposed at 70 degrees F with mean droplet size 0.9 microns showed no marked effect on function or symptoms. Asthmatics showed dose-related decrements in forced expiratory performance and increases in symptoms, most obvious at 1000 and 2000 micrograms/m3. The different results of the two studies probably reflect an influence of droplet size, but further investigation is needed to confirm this. The aggregate results suggest that only mild, if any, short-term respiratory irritant effects are likely at acid concentrations attained in ambient pollution.

Acid Rain↗
PubMed2003

Free-space ballistic laser propagation of a pulse coded data stream through fog.

We describe the use of space and polarization gates in a study of free-space optical communication of a coded pulse train as it passes through turbid media. The propagation of coded signals at 10 GHz through adverse environmental conditions is demonstrated. Polarization and space-gating techniques are used to improve the signal-to-noise ratio and to enhance the information fidelity of high-bit-rate transmitted signals, which shows potential improvement for cloud, fog, and smog applications.

Journal Article↗
PubMed2004

Numerical studies on time-domain responses of on-off-keyed modulated optical signals through a dense fog.

We present a numerical technique to simulate the propagation characteristics of an on-off-keyed modulated optical signal through fog. The on-off-keyed modulated light (a square wave) is decomposed into a finite number of harmonic components, and a numerical solution for the vector radiative transfer equation is obtained for each harmonic that corresponds to the modulation frequency. With this method we study the distortion and the pulse spread in the received signal due to attenuation and scattering. We investigate the propagation characteristic of the modulated signal with different communication system parameters. This information can be used to study communication channel reliability.

Journal Article↗