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At least 19 recordsLinked to original sources
PubMed2004

Do central vacuum cleaners produce less indoor airborne dust or airborne cat allergen, during and after vacuuming, compared with regular vacuum cleaners?

UNLABELLED: Vacuum cleaners with a central exhaust may lead to lower airborne dust and allergen concentrations compared with regular vacuum cleaners. In 12 houses, equipped with a central vacuum cleaning system, a standardized vacuum cleaning protocol was performed comparing airborne dust and allergen concentrations between the central system and a regular cleaner. Airborne dust concentrations during (104 vs. 95 microg/m(3)) and after vacuum cleaning (38 vs. 36 microg/m(3)) were not significantly different. In houses with a cat, Fel d 1 concentrations were also not significantly different either during (6.12 vs.5.91 ng/m(3)) and after (0.64 vs. 0.91 ng/m(3)) use of the vacuum cleaners. Airborne dust and Fel d 1 concentrations increased considerably during use of both vacuum cleaners. Compared with central vacuum cleaning systems, conventional modern vacuum cleaners do not cause higher airborne dust or cat allergen concentrations during and after use. PRACTICAL IMPLICATIONS: This study shows that the amount of dust or cat allergen in the air during and after vacuum cleaning is similar when comparing a central vacuum cleaner with a regular vacuum cleaner. Therefore, allergen avoidance advice given to reduce exposure of allergic asthmatic patients to allergens, does not necessarily have to include switching to a central vacuum cleaner.

Air Pollution, Indoor↗
PubMed2005

Comparison of work rates, energy expenditure, and perceived exertion during a 1-h vacuuming task with a backpack vacuum cleaner and an upright vacuum cleaner.

The purpose of this study was to evaluate two types of industrial vacuum cleaners, in terms of cleaning rates, energy expenditure, and perceived exertion. Twelve industrial cleaners (six males and six females, age 28-39 yr) performed two 1-h vacuuming tasks with an upright vacuum cleaner (UVC) and a backpack vacuum cleaner (BPVC). Measures for oxygen uptake (VO2) and ratings of perceived exertion (RPE) were collected continuously during the 1-h vacuuming tasks. Cleaning rates for the UVC and BPVC were 7.23 and 14.98 m2min(-1), respectively. On a separate day subjects performed a maximal treadmill exercise test to determine their maximal aerobic capacity (peak VO2). Average absolute energy costs (in Metabolic equivalents), relative energy costs of the vacuum task compared to the subjects' maximal aerobic capacity (% peak VO2), and RPE responses for the 1-h vacuuming tasks were similar between vacuum cleaners, but % peak VO2 and RPE values differed between genders. These results indicate that the BPVC was more efficient than the UVC. With the BPVC, experienced workers vacuumed at a cleaning rate 2.07 times greater than the UVC and had similar levels of energy expenditure and perceived effort, compared to the slower cleaning rate with the UVC.

Adult↗
PubMed1986

Cohort study of Silastic obstetric vacuum cup deliveries: II. Unsuccessful vacuum extraction.

In a cohort analysis of Silastic vacuum extractor deliveries, 65% were completed with the vacuum extractor alone, 24% with outlet forceps, 3% with midforceps, and 7% with cesarean section (vacuum extractor-cesarean). Control groups were formed by using the next sequential forceps delivery, spontaneous vaginal delivery, and every second cesarean section after a trial of labor. The infants were examined using a neurobehavioral scale, an encephalopathy assessment, cranial ultrasound, and indirect ophthalmoscopy. In the combined vacuum extractor and forceps delivery subgroup (vacuum extractor-forceps), all but 3% were converted from a high mid-forceps delivery to outlet forceps by the initial vacuum extractor procedure, thus eliminating many difficult midforceps deliveries. The study yielded no significant difference in maternal morbidity between vacuum extractor-forceps and forceps delivery, no difference in vaginal trauma for vacuum extractor-cesarean versus vacuum extractor delivery, and no greater hospital stay, infection rate, or need for transfusion for either vacuum extractor-forceps versus forceps delivery or vacuum extractor-cesarean versus cesarean delivery. Neonatal morbidity did not differ between successful and unsuccessful trial of vacuum extractor, except for an increased frequency of retinal hemorrhage. The frequency of scalp trauma, including cephalohematoma, did not differ between vacuum extractor-forceps and forceps delivery, or between vacuum extractor-cesarean and vacuum extractor delivery. For vacuum extractor-forceps versus forceps delivery and vacuum extractor-cesarean versus cesarean section, there were no significant differences in neurobehavioral or encephalopathy scores, or in the frequency of neonatal jaundice, facial palsy, anemia, fractures, or mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Cesarean Section↗
PubMed2000

Effects of milkline vacuum, pulsator airline vacuum, and cluster weight on milk yield, teat condition, and udder health.

The influence of milkline vacuum, pulsator airline vacuum, and cluster weight on complete lactation milk yield performance, teat condition, and udder health were studied in 241 cows by using three separate factorial experiments. The first experiment had milkline vacuum set at 38 and 48 kPa, pulsator airline was vacuum was set at 0 and 8 kPa above milkline vacuum, and cluster weight was 1.6 and 2.3 kg. The second experiment had milkline vacuum set at 38 and 48 kPa and cluster weight was 1.6 and 2.3 kg. The third experiment had milkline vacuum set at 32 and 42 kPa and pulsator airline vacuum 0 and 8 kPa above milk line vacuum. The first two experiments were carried out with a high-level milking and the third with a low-level milking system. The average vacuums in the short milk tube during milking for low and high milkline vacuum in the high-level system were 26 and 33 kPa, and 30 and 39 kPa for the low-level milking system, respectively. Milking at low vacuum increased the machine-on time and frequency of liner slip, decreased milk flow rate, but had no influence on teat condition and udder health. The milk yield of high producing cows with long machine-on time was reduced by 5% when milked at a low vacuum. A higher pulsator airline vacuum than milkline vacuum had no influence on milking performance. The use of the light cluster reduced machine-on time. We recommend that mean vacuum in the short milk tube should not be lower than 32 kPa.

Animals↗
PubMed1999

Assessment of vacuum cleaners and vacuum cleaner bags recommended for allergic subjects.

BACKGROUND: High-quality vacuum cleaners and vacuum cleaner bags are often recommended to allergic patients as a means of reducing indoor allergen exposure. A number of vacuum cleaners on the market today claim to capture 99.9% of particles 0.3 microm or larger entering the vacuum cleaner, and many vacuum cleaner bags are now being sold as microfiltration bags. OBJECTIVE: The purpose of this study was to compare the allergen-trapping abilities of vacuum cleaners and to use a new technique for testing vacuum cleaner bags that are recommended for allergic patients. METHODS: Vacuum cleaners were tested in an 18-m(3) laboratory room permeated with dust containing high levels of cat allergen by using techniques previously described. Air was sampled with parallel filters in conjunction with a particle counter. The filters were assayed by ELISA for cat allergen (Fel d 1). Vacuum cleaner bags were tested by using a modified dust trap to pull sieved house dust containing a known amount of Fel d 1 across the material used for the bag. Allergen passing through the bag was trapped on a filter covering the exit of the trap and analyzed for Fel d 1. RESULTS: In general, vacuum cleaners designed for allergic patients leaked lower amounts of allergen (<0.5-4.04 ng/m(3)) than that found in our previous studies (<0.5-100 ng/m(3)). Single-layer vacuum cleaner bags performed poorly (1250-2640 ng recovered) compared with most of the 2- and 3-layer microfiltration bags (0.53-2450 ng recovered). The range of allergen recovered from the 2-layer bags (0.93-2450 ng recovered) highlighted the variability found between manufacturers. CONCLUSION: The results suggest that although allergen leakage has been reduced, there is still room for improvement. A method of testing allergen leakage by using Fel d 1 should be applied to vacuum cleaners and bags recommended for allergic patients.

Air Pollution↗
PubMed1997

Reduction of the mite-allergen reservoir within mattresses by vacuum-cleaning. A comparison of three vacuum-cleaning systems.

Mattresses are considered to be the main source of house-dust-mite (HDM) allergen. This study aimed to investigate different types of vacuum cleaners for their ability to reduce this allergen reservoir. Three types of vacuum cleaners were examined: a conventional vacuum cleaner, a water-trap cleaner, and a central vacuum cleaner. Cut out pieces of mattresses were analyzed for content of mite allergen after vacuum-cleaning. Three polyester mattresses from the homes of three children were selected for the study. These three mattresses had earlier been found to be contaminated by group 1 HDM allergen (8-15 micrograms/g of dust). Each mattress was divided into three main sections, separated by a safety zone, and each main section was subdivided into four parts. The three main sections were cleaned by each vacuum-cleaning system. Pieces 2-cm-thick of the surface of the mattresses were cut out, and extracts were made to assess the amount of mite allergen still present after different intensities of vacuum-cleaning. A considerable reduction in the level of mite allergen was found after using all three of the vacuum-cleaning systems. Only 22% of the original mite-allergen reservoir remained after intense vacuum-cleaning. Since the number of mattresses in the investigation was low, and niche formations of group 1 HDM allergen within the mattresses were observed, the results must be interpreted with caution. Furthermore, allergen-producing living dust mites were not affected by this method. However, intense vacuum-cleaning seems to reduce considerably the level of the mattress-bound mite-allergen reservoir, a fact which may be important in mite-allergic and mite-exposed families.

Allergens↗
PubMed2003

Physical demands of vacuuming in women using different models of vacuum cleaners.

PURPOSE: Women continue to have the primary responsibility for housekeeping, even after a cardiac event. Vacuuming is one housekeeping task that is often reported as difficult to perform due to angina symptoms. The aim of this study was to evaluate the energy expenditure and hemodynamic responses associated with vacuuming using five different models of vacuum cleaners. METHODS: Thirty-six healthy women 50-59 yr of age (54.5 +/- 3.1 yr) participated in this study. Energy expenditure was measured by indirect calorimetry using an Aerosport KB1-C portable metabolic system. After collection of baseline HR, blood pressure (BP), and oxygen consumption ( VO2 ) data, subjects performed vacuuming and treadmill walking in one of six different sequences. Vacuuming consisted of using five different models of vacuum cleaners, three upright models (heavy-duty, self-propelled, and lightweight) and two canister models (standard and compact) for 6 min each. Treadmill walking was conducted at 2.0 mph (0% grade) for 6 min. VO2, HR, BP, and RPE were recorded during each task. The rate-pressure product (RPP) was calculated to estimate myocardial oxygen demand. RESULTS: Vacuuming with the self-propelled upright model resulted in significantly lower VO2, RPE, HR, systolic BP, and RPP responses compared with some of the other models.(2) CONCLUSION: Significant differences in oxygen consumption and myocardial oxygen demand are associated with vacuuming using different models of vacuum cleaners. When making recommendations to individuals regarding the least physiologically demanding models, the power assist features of the machine should be the greatest consideration. This important characteristic should be taken into account when making recommendations for patients with limited capacity, or those wanting to limit physiological stress due to a disease state.

Blood Pressure↗
PubMedDate not supplied

[The correlation between milk flow, vacuum fluctuations and decrease in vacuum in the long milk tube at the claw in different milking machines. An introductory examination (author's transl)].

Four different milking machines have been examined for vacuum fluctuations and vacuum decrease in the long milk tube at the claw. Measurements were performed in 3 cows milked with Alfa-Laval high line HP 100, 11 cows in 3 herds milked with Alfa-Laval high line Duovac 300, 5 cows milked with Erland low line milking equipment, and in 3 cows milked with Strangko high line milking equipment. The recordings were done in the cowhouse during the daily dairy management. The milk flow for each cow was measured 24 hrs after the vacuum recordings using Milko-Scope. Compared to the other 3 milking machines, Duovac 300 had a significant higher increase in vacuum fluctuations and vacuum decrease with the increase in milk flow. Just small differences existed between Alfa-Laval HP 100 and Strangko milk pipe line equipments. Smaller vacuum fluctuations and vacuum decrease were recorded in the low line milking equipments compared to the other types. The difference was significant (P = less than 0.001). Significant correlations between milk flow and decrease in vacuum, and between milk flow and vacuum fluctuations were not found for the low line milking machine examined.

Animals↗
PubMed2004

Static and dynamic experiments in cryo-electron microscopy: comparative observations using high-vacuum, low-voltage and low-vacuum SEM.

We carried out a unique comparative study between three modes of cryo-scanning electron imaging: high-vacuum, low-voltage and low-vacuum, using ice cream as a model system. Specimens were investigated both with and without a conductive coating (Au/Pd) and at temperatures for which ice either remains fully frozen (< -110 degrees C) or undergoes sublimation (-110 to -90 degrees C). At high magnification, high-vacuum imaging of coated specimens gave the best results for 'static' specimens (i.e. containing fully frozen ice). Low voltages, such as 1 kV, could be used for imaging uncoated specimens at high vacuum, although slight 'classical' charging artefacts remained an issue, and the reduced electron beam penetration tended to decrease the definition between different microstructural features. However, this mode was useful for observing in situ sublimation from uncoated specimens. Low-vacuum mode, involving small partial pressures of nitrogen gas, was particularly suited to in situ sublimation work: when sublimation was carried out in low vacuum in the absence of an anti-contaminator plate, sublimation rates were significantly reduced. This is attributed to a small partial pressure of sublimated water vapour remaining near the specimen surface, enhancing thermodynamic stability.

Journal Article↗
PubMedDate not supplied

Comparison of the diagnostic accuracy of a vacuum-assisted percutaneous intact specimen sampling device to a vacuum-assisted core needle sampling device for breast biopsy: initial experience.

The objective of this research was to determine whether biopsy of the breast using a percutaneous intact specimen sampling device influences the underestimation rate of ductal carcinoma in situ (DCIS) compared to a vacuum-assisted core needle biopsy (VACNB) device. This study was a retrospective comparison of two series of 800 consecutive patients that underwent stereotactic biopsy of the breast for mammographic lesions presenting as microcalcifications classified by our institution as Breast Imaging Reporting and Data System (BI-RADS) 4 or 5. In the first series of patients (n = 800), a VACNB device was used; in the second series (n = 800), a vacuum-assisted percutaneous intact specimen biopsy (VAPIB) device was used. Initial diagnoses were made from the histopathologic examination of the tissue retrieved at biopsy. Lesions presenting as DCIS or atypical ductal hyperplasia (ADH) after percutaneous biopsy were then compared to the histopathologic analysis of specimens retrieved at surgical biopsy. DCIS upgrades were defined as cases in which the diagnosis of the stereotactic biopsy was DCIS and the diagnosis of the subsequent surgical excision was infiltrating ductal carcinoma (IDC). ADH upgrades were defined as cases in which the diagnosis of the stereotactic biopsy specimen was ADH and the diagnosis of the surgical excision was DCIS, lobular carcinoma in situ (LCIS), or IDC. The lesions retrieved by both biopsy techniques yielded a similar pathology distribution. Underestimation of DCIS occurred less frequently (p = 0.06) in the biopsy samples taken using the intact biopsy device (1/31, 3.2%) as compared to biopsy samples taken using the core needle biopsy device (7/36, 19.4%). No significant adverse events were reported. Breast biopsy can be performed safely and accurately using a vacuum-assisted percutaneous intact specimen sampling device. In this study, such a device trended toward fewer underestimations of DCIS at biopsy compared to the vacuum-assisted core needle sampling biopsy method.

Biopsy↗
PubMed1992

A comparison of leakage of filling materials in demineralized and non-demineralized resected root ends under vacuum and non-vacuum conditions.

A study was conducted to compare the marginal apical leakage of root-end filling materials under vacuum and non-vacuum conditions, and to assess the effect of demineralization by application of citric acid to the root ends on the apical marginal leakage of root end filling materials. The root canals of 148 extracted human canines and premolars were handfiled and sealed with gutta-percha and Roth's 801 sealer using cold lateral condensation. The teeth were divided into 8 groups that received retrofilling materials. The materials tested were amalgam, IRM and gutta-percha/sealer with and without successive application of citric acid. Half of the specimens were placed under vacuum conditions in methylene blue dye, and the other half were placed in the dye for the same time period without exhausting air from the flask. The teeth were split longitudinally and the extent of dye penetration was determined with a stereomicroscope and eyepiece micrometer. The most evident difference in dye penetration was found between the positive control groups. Under vacuum conditions, the positive controls showed complete penetration of the unobturated canal system with dye. With passive immersion only partial penetration of the unobturated canal system occurred. Application of citric acid to the root end did not adversely affect the seal of amalgam, IRM or gutta-percha/sealer.

Acid Etching, Dental↗
PubMed1998

Spontaneous vacuum pneumarthrography revisited: the significance of the vacuum phenomenon in the lateral compartment of the knee.

We report seven cases of spontaneous vacuum phenomenon of the lateral compartment of the knee. Previous reports of the vacuum phenomenon suggest that it is related to traction on a joint or the absence of an effusion. The presence of this finding on plain radiographs, or artifacts associated with it on magnetic resonance imaging, have been said to create a false-positive indication for meniscal tears, especially in the medial compartment. We describe plain radiographic, magnetic resonance, and arthroscopic findings in seven consecutive patients with vacuum phenomenon of the lateral compartment of the knee and conclude that this finding may be a true-positive indication for degenerative meniscal tears and chondrosis. The etiology of this finding and its long-term significance remains unclear.

Arthrography↗
PubMed2001

The usefulness of the modified extra-oral vacuum aspirator (EOVA) from household vacuum cleaner in reducing bacteria in dental aerosols.

AIMS AND OBJECTIVES: Currently, as a preventive measure against air contamination caused by dental procedures, dust-collecting aspirators such as an extra-oral vacuum aspirator (EOVA) are coming into general use. In this study, we tested the ability of a modified EOVA that uses a household vacuum machine. DESIGN AND SETTING: The study was conducted in two parts. First, the modified EOVA was tested for its ability to eliminate an Escherichia coli aerosol generated in a manikin. Second, the device was tested for its ability to remove the aerosol generated by dental treatment procedures, scaling and drilling a tooth, on human subjects. RESULTS: There was a statistically significant reduction in both the E. coli aerosol and the oral bacterial aerosol during dental treatment procedures. CONCLUSION: The modified EOVA machine is highly effective in preventing air contamination by dental procedures. Its main advantages are that it can easily be modified for use with any dental unit and it is relatively inexpensive.

Aerosols↗
PubMed2005

Coexistence of intravertebral vacuum and intradiscal vacuum.

INTRODUCTION: The pathophysiology of intravertebral vacuum (IVV) remains unclear, although vertebral osteonecrosis is often incriminated. Gas may migrate from the disk to the vertebral body. The objective of this study was to investigate the relations between IVV and intradiscal vacuum (IDV). METHODS: We prospectively evaluated the presence of radiological findings suggestive of IVV in patients admitted to a rheumatology department for vertebral fracture, over a 6-year period. Suggestive radiological findings were defined as a radiolucent collection within a vertebral body, an increase in the anteroposterior diameter of the vertebral body, and/or evidence of horizontal dissection of a vertebral body. Patients with any of these findings underwent computed tomography; when this investigation showed IVV, the adjacent disks were examined for IDV, and when this was found a communication between the two cavities was looked for. RESULTS: Of 278 patients admitted for vertebral fracture during the study period, 15 had IVV. IDV adjacent to the fractured endplate was visible in 13 of these 15 patients. All 15 patients had severe fractures (Genant semi-quantitative classification, grade 3 in 10 patients and grade 2 in five patients). A communication between the intradiscal and intravertebral collections was seen in five patients. Only two patients had evidence of IVV on plain radiographs. CONCLUSION: Our findings support migration of gas from the disk to a fracture in the adjacent vertebral body. The term "vertebral osteonecrosis" used to designate IVV may be inappropriate. IVV is rarely shown by plain radiographs, indicating a need for other morphological criteria.

Aged↗
PubMed2003

Similarities in women's perceptions and acceptability of manual vacuum aspiration and electric vacuum aspiration for first trimester abortion.

This paper examines women's acceptability of and experiences with manual vacuum aspiration (MVA) as compared with electric vacuum aspiration (EVA) for first trimester abortion. Women requesting pregnancy terminations were randomly assigned to either MVA (n = 64) or EVA (n = 63). Participants completed questionnaires before and after their abortions and approximately 2-4 weeks later. We observed some differences by group in participants' ratings of the importance of method characteristics and in their perceptions of their abortion methods after their abortions. The two groups did not, however, differ in their reports of pain, anxiety or bleeding or in the acceptability of their method.

Abortion, Induced↗
PubMed2004

Marginal adaptation of mineral trioxide aggregate (MTA) compared with amalgam as a root-end filling material: a low-vacuum (LV) versus high-vacuum (HV) SEM study.

AIM: To compare the marginal adaptation of mineral trioxide aggregate (MTA) or amalgam root-end fillings in extracted teeth under low-vacuum (LV) versus high-vacuum (HV) scanning electron microscope (SEM) viewing conditions. METHODOLOGY: Root-end fillings were placed in 20 extracted single-rooted maxillary teeth. Ten root ends were filled with MTA and the other 10 root ends were filled with amalgam. Two 1 mm thick transverse sections of each root-end filling were cut 0.50 mm (top) and 1.50 mm (bottom) from the apex. Gap size was recorded at eight fixed points along the dentine-filling material interface on each section when uncoated wet (LV wet (LVW)) and dry under LV (0.3 Torr) in a JEOL JSM-5800 SEM and backscatter emission (LV dry uncoated (LVDU)). The sections were then air-dried, gold-coated and gap size was recorded once again at the fixed points under HV (10(-6) Torr; HV dry coated (HVDC)). Specimen cracking, and the size and extent of the crack were noted. RESULTS: Gap sizes at fixed points were smallest under LVW and largest under HVDC SEM conditions. Gaps were smallest in MTA root-end fillings. A General Linear Models Analysis, with gap size as the dependent variable, showed significant effects for extent of crack in dentine, material and viewing condition (P = 0.0001). CONCLUSIONS: This study showed that MTA produced a superior marginal adaptation to amalgam, and that LVW conditions showed the lowest gap size. Gap size was influenced by the method of SEM viewing. If only HV SEM viewing conditions are used for MTA and amalgam root-end fillings, a correction factor of 3.5 and 2.2, respectively, may be used to enable relative comparisons of gap size to LVW conditions.

Aluminum Compounds↗
PubMed2002

Use of vacuum-steam-vacuum and ionizing radiation to eliminate Listeria innocua from ham.

Listeria spp. are a frequent postprocess contaminant of ready-to-eat (RTE) meat products, including ham. Vacuum-steam-vacuum (VSV) technology has been used successfully to eliminate Listeria innocua from hot dogs. Ionizing radiation can eliminate Listeria spp. from RTE meats. However, the excessive application of either technology can cause changes in product quality, including structural changes, changes in cure color (redness), and lipid oxidation. In this study, two cycles of VSV were combined with 2.0 kGy of ionizing radiation to obtain 4.40- and 4.85-log10 reductions of L. innocua on ham meat and skin, respectively. The use of both treatments resulted in an additive, as opposed to synergistic, reduction of L. innocua on ham. The combination treatment did not cause statistically significant changes in product structure, color (redness), or lipid oxidation.

Animals↗