用色质联用方法对蓄电池盒生产车间硫化烟气成分的分析

用气相色谱－质谱（简称色质联用，ＧＣ／ＭＳ）方法分析了蓄电池盒生产车间硫化烟气的成份，从中分析出芘及荧蒽２个多环芳烃化合物，为硫化烟气的致突变、致癌作用提供了证据。     

Metal fume fever presenting as aseptic meningitis with pericarditis, pleuritis and pneumonitis

BACKGROUND: Metal fume fever (MFF) is a well-known complication of zinc oxide fume inhalation. Prompt recognition of this condition is essential for the proper medical management of this self-limited disease. AIM: To present a unique and unusual case of MFF. RESULTS: Our patient is a 25-year-old male welder who had MFF and presented with aseptic meningitis with pericarditis, pleuritis and pneumonitis. To our knowledge, this is the first case of MMF presenting with these signs and symptoms. CONCLUSIONS: MFF can present with a systemic inflammatory response causing a multi-organ serositis. Our case highlights the utmost importance of obtaining an occupational history on all our patients, even if they are critically ill.     

Near infrared laser-tissue welding using nanoshells as an exogenous absorber

BACKGROUND AND OBJECTIVE: Gold nanoshells are a new class of nanoparticles that can be designed to strongly absorb light in the near infrared (NIR). These particles provide much larger absorption cross-sections and efficiency than can be achieved with currently used chemical chromophores without photobleaching. In these studies, we have investigated the use of gold nanoshells as exogenous NIR absorbers to facilitate NIR laser-tissue welding. STUDY DESIGN/MATERIALS AND METHODS: Gold nanoshells with peak extinction matching the NIR wavelength of the laser being used were manufactured and suspended in an albumin solder. Optimization work was performed on ex vivo muscle samples and then translated into testing in an in vivo rat skin wound-healing model. Mechanical testing of the muscle samples was immediately performed and compared to intact tissue mechanical properties. In the in vivo study, full thickness incisions in the dorsal skin of rats were welded, and samples of skin were excised at 0, 5, 10, 21, and 32 days for analysis of strength and wound healing response. RESULTS: Mechanical testing of nanoshell-solder welds in muscle revealed successful fusion of tissues with tensile strengths of the weld site equal to the uncut tissue. No welding was accomplished with this light source when using solder formulations without nanoshells. Mechanical testing of the skin wounds showed sufficient strength for closure and strength increased over time. Histological examination showed good wound-healing response in the soldered skin. CONCLUSIONS: The use of nanoshells as an exogenous absorber allows the usage of light sources that are minimally absorbed by tissue components, thereby, minimizing damage to surrounding tissue and allowing welding of thicker tissues.     

Repair of pig dura in vivo using temperature controlled CO(2) laser soldering

BACKGROUND AND OBJECTIVES: The purpose of this study was to demonstrate that laser soldering might be successfully used for closing holes or cuts in the dura layer, which encapsulates the brain. STUDY DESIGN/MATERIALS AND METHODS: A temperature controlled fiberoptic CO(2) laser system and albumin solder were used for spot soldering of fascia patches to holes in the dura of farm pigs, in vitro and in vivo. RESULTS: The mean burst pressure of the soldered patches in the in vitro experiments was 190 +/- 88 mm Hg-significantly higher than typical maximum CSF pressure of 15 mm Hg. In the in vivo experiments the pigs showed no postoperative complications. Histopathological studies exhibited an accepted level of inflammatory reaction and showed no thermal damage to the underlying brain tissue. CONCLUSIONS: It has been clearly demonstrated that temperature controlled laser soldering is a very useful technique for the repair of the dura. It provides significant advantages over standard closure techniques: it is easy to apply, the bond is strong and watertight and the procedure is likely to be much faster than suturing. This research work will lead to clinical trials.     

Potential Oxidative Stress in the Bodies of Electric Arc Welding Operators： Effect of Photochemical Smog

INTRODUCTION Electric arc welding is widely used in many fields such as welding engineering, architectural engineering, automotive industry, boat and ship engineering, aerospace C…     

Suppression in lung defense responses after bacterial infection in rats pretreated with different welding fumes

Epidemiology suggests that inhalation of welding fumes increases the susceptibility to lung infection. The effects of chemically distinct welding fumes on lung defense responses after bacterial infection were compared. Fume was collected during gas metal arc (GMA) or flux-covered manual metal arc (MMA) welding using two consumable electrodes: stainless steel (SS) or mild steel (MS). The fumes were separated into water-soluble and -insoluble fractions. The GMA-SS and GMA-MS fumes were found to be relatively insoluble, whereas the MMA-SS was highly water soluble, with the soluble fraction comprised of 87% Cr and 11% Mn. On day 0, male Sprague-Dawley rats were intratracheally instilled with saline (vehicle control) or the different welding fumes (0.1 or 2 mg/rat). At day 3, the rats were intratracheally inoculated with 5 x 10(3) Listeria monocytogenes. On days 6, 8, and 10, left lungs were removed, homogenized, cultured overnight, and colony-forming units were counted to assess pulmonary bacterial clearance. Bronchoalveolar lavage (BAL) was performed on right lungs to recover phagocytes and BAL fluid to measure the production of nitric oxide (NO) and immunomodulatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-2, IL-6, and IL-10. In contrast to the GMA-SS, GMA-MS, and saline groups, pretreatment with the highly water soluble MMA-SS fume caused significant body weight loss, extensive lung damage, and a dramatic reduction in pulmonary clearance of L. monocytogenes after infection. NO concentrations in BAL fluid and lung immunostaining of inducible NO synthase were dramatically increased in rats pretreated with MMA-SS before and after infection. MMA-SS treatment caused a significant decrease in IL-2 and significant increases in TNF-alpha, IL-6, and IL-10 after infection. In conclusion, pretreatment with MMA-SS increased production of NO and proinflammatory cytokines (TNF-alpha and IL-6) after infection, which are likely responsible for the elevation in lung inflammation and injury. In addition, MMA-SS treatment reduced IL-2 (involved in T cell proliferation) and enhanced IL-10 (involved in inhibiting macrophage function) after bacterial infection, which might result in a possible suppression in immune response and an increase in susceptibility to infection.     

Pulmonary effects of welding fumes: review of worker and experimental animal studies

BACKGROUND: Approximately one million workers worldwide perform welding as part of their work duties. Electric arc welding processes produce metal fumes and gases which may be harmful to exposed workers. METHODS: This review summarizes human and animals studies which have examined the effect of welding fume exposure on respiratory health. An extensive search of the scientific and occupational health literature was performed, acquiring published articles which examined the effects of welding on all aspects of worker and laboratory animal health. The databases accessed included PubMed, Ovid, NIOSHTIC, and TOXNET. RESULTS: Pulmonary effects observed in full-time welders have included metal fume fever, airway irritation, lung function changes, susceptibility to pulmonary infection, and a possible increase in the incidence of lung cancer. Although limited in most cases, animal studies have tended to support the findings from epidemiologic studies. CONCLUSIONS: Despite the numerous studies on welding fumes, incomplete information still exists regarding the causality and possible underlying mechanisms associated with welding fume inhalation and pulmonary disease. The use of animal models and the ability to control the welding fume exposure in toxicology studies could be utilized in an attempt to develop a better understanding of how welding fumes affect pulmonary health.     

Comparison of argon-laser welded and sutured repair of inferior vena cava in a canine model

BACKGROUND AND OBJECTIVE: Advantages of laser-welded microarterial anastomoses have been reported. However, whether laser repair of large veins is advantageous is not yet known. Argon-laser welding of inferior vena cava was therefore compared with conventional-sutured repair. STUDY DESIGN/MATERIALS AND METHODS: Twenty-four adult mongrel dogs were used. Twelve inferior vena cavas were repaired using an argon laser and the rest using continuous sutures. Specimens were removed at 2, 8, 16, and 24 weeks after repair. Technical characteristics, cavographical findings, and results of histopathological study using light and transmission electron microscopy were compared. RESULTS: Procedure time did not significantly differ between the two groups. The sutured repair sites were narrower than those repaired by laser immediately after and at 2 and 24 weeks. Histologically, laser welding resulted from denaturation of collagen and mild healing occurred simultaneously with the disappearance of denatured collagen. By contrast, there was strong fibrotic reaction at sutured repair sites. CONCLUSIONS: These findings suggest that argon-laser repair of large veins is superior to continuous suturing.     

Passive fit of frameworks in titanium and palladium–silver alloy submitted the laser welding

Summary  This study evaluated the precision of fit of implant frameworks cast in titanium (cp Ti) and palladium–silver alloy (Pd-Ag), made by the one-piece cast and laser welding techniques. From a metal matrix with five implants, 20 master casts were obtained, to which replicas of implants were incorporated. On these masters 10 frameworks were made for each type of material (cp Ti and Pd-Ag alloy). Half of these were made by the one-piece cast technique and the other half by the laser welding technique. The implant/prosthesis interface was analysed and measured in the vestibular and lingual regions of the central and distal implants with the help of a measuring microscope. The results indicated that in the central cylinders, the Tukey test ( P  < 0·0005) showed a significant difference in the passive fit between the laser-welded frameworks (34·73 μm) and those one-piece cast frameworks (151·39 μm), and as regards materials, the palladium–silver alloy (66·30 μm) showed better results than the titanium (119·83 μm). In the distal cylinders there was no significant difference between the frameworks cast in titanium and palladium–silver by the one-piece technique. However, after laser welding, there was a significant difference for the frameworks cast in titanium (31·37 μm) and palladium–silver (106·59 μm).