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<p><b>OBJECTIVE</b>To investigate the characteristics of exposure to iron oxide nanoparticles in workplace.</p><p><b>METHODS</b>The real-time particle number (NC), surface area (SAC), and mass (MC) concentrations of nanoparticles were measured in various locations of a selected workplace manufacturing iron oxide nanoparticles. The collected particles were analyzed for morphology and elemental composition.</p><p><b>RESULTS</b>The average NCs and SACs in milling site (16,566 pt/cm3, 106.082 µm2/cm3), packaging site (12,386 pt/cm3, 89.861 µm2/cm3), shipping site (13,808 pt/cm3, 102.071 µm2/cm3), and product storage room (17,192 pt/cm, 115.044 µm2/cm3) of the yellow powder (α-Fe2O3 . nH2O) were all significantly higher than the workplace background concentrations (11,420 pt/cm3, 85.026 µm2/cm3) (all P<0.05). The NC was highly correlated with the SAC (r= 0.784), while both NC and SAC were loosely correlated with the MC (r1=0.323, r2=0.331). Scanning electron microscopy revealed a spindle-like shape of the iron oxide nanoparticle; the chemical composition of the collected particles contained 19.33 weight percent iron (Fe).</p><p><b>CONCLUSION</b>The milling site and product storage room of the yellow powder are exposed to a higher concentration of nanoparticles, which are mainly composed of iron oxide nanoparticles. The NC is highly correlated with the SAC.</p>
Subject(s)
Ferric Compounds , Metal Nanoparticles , Occupational Exposure , WorkplaceABSTRACT
Objective To observe the efficacy of folic acid combined with mecobalamine for the treatment of vascular mild cogni-tive impairment (VMCI) in patients with cerebral small vessel disease (SVD) and hyperhomocysteinemia(Hcy) .Methods A total of 84 VMCI patients with cerebral small vessel disease and Hcy were randomly divided into combination group and control group . Two groups received conventional therapy for 6 months .Besides ,the combination group received folic acid combined with mecobal-amin .The level of plasma Hcy and ADAS-cog score were observed before and after 3 months and 6 months treatment .Results Af-ter treatment ,plasma Hcy significantly lower in the combination group (P0 .05) .However ,after 6 months treatment ,the ADAS-cog scores decreased obviously than that in the before treatment group (P0 .05) .After 3 months treatment ,there was no significant difference on ADAS-cog score between combination group and control group (P>0 .05) ,however ,there had significant difference between the two groups after 6 months treatment(P<0 .05) .Conclusion The level of plasma Hcy could be reduced by adding folic acid and mecobalamin .Treatment of hyperhomocysteinemia may delay the progression of vascular cognitive impairment w hich caused by cerebral small vessel disease .
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<p><b>OBJECTIVE</b>To develop a method for determination of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the air of workplace by high-performance liquid chromatography.</p><p><b>METHODS</b>2, 4-D was collected by ultrafine glass filters, desorbed by methanol, separated by a C18 column, and detected by a UV detector. Identification and quantification of 2, 4-D were performed by retention time and peak areas, respectively.</p><p><b>RESULTS</b>The linear range of the test was 2∼200 µg/ml; the elution efficiency was 94.6%- 95.9%; the limit of detection (S/N = 3) was 0.034 µg/ml (injection volume of 20 µl eluant); the lower limit of quantification (S/N = 10) was 0.11 µg/ml; the minimum detectable concentration was 0.011 mg/m(3); the minimum quantifiable concentration was 0.037 mg/m(3) (with sampled air volume of 45 L).</p><p><b>CONCLUSION</b>This method is convenient and simple in sample collection and preparation, and satisfies all methodological requirements. Therefore, this method is useful for the determination of 2, 4-D in the air of workplace.</p>
Subject(s)
2,4-Dichlorophenoxyacetic Acid , Air , Air Pollutants, Occupational , Chromatography, High Pressure Liquid , Methods , WorkplaceABSTRACT
Objective To evaluate the effects of penehyclidine hydrochloride (PHC) on the expression of Toll like receptor-4 (TLR4) and nuclear factor kappa B (NF-κcB) in a rat model of sepsis-induced acute lung injury (ALI).Methods Seventy-two adult male Sprague-Dawley rats,weighing 180-220 g,were randomly divided into 3 groups (n =24 each) using a random number table:shame operation group (group S),ALI group and PHC group.Sepsis-induced ALl was induced by cecal ligation and puncture in anesthetized rats.In group PHC,PHC 0.45 mg/kg was intramuscularly injected immediately after cecal ligation and puncture.At 6,12,24 and 36 h after ligation,the broncho-alveolar lavage fluid (BALF) was collected for detection of TNF-α and IL-6 concentrations and the lungs were removed for determination of the expression of TLR4 (using RT-PCR and Western blot) and NF-κBp65 (using Western blot) in lung tissues and for microscopic examination.The pathological changes of lungs were scored.The wet to dry lung weight (W/D) ratio was calculated and the activity of myeloperoxidase (MPO) in lung tissues was measured.Results As compared with S group,the IL-6 concentrations in BALF at 6,12 and 24 h after ligation,TNF-α concentration in BALF at 6 and 12 h after ligation,and the expression of TLR4 and NF-κBp65,pathological scores,W/D ratio and MPO activity at each time point were significantly increased in ALI group (P ＜ 0.05).Compared with ALI group,the TNF-α concentration in BALF at 6 and 12 h after ligation,and IL-6 concentrations in BALF,the expression of TLR4 and NF-κBp65,pathological scores,W/D ratio and MPO activity at each time point were significantly decreased in group PHC (P ＜ 0.05).Conclusion PHC inhibits NF-κB activation and decreases inflammatory responses through blocking TLR4 expression in lung tissues,thus attenuating sepsis-induced ALI in rats.
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AIM: To establish a Reversed-Phase high performance liquid chromatography method for determination of plasma ropivacaine in dog.METHODS:The sample was deproteinated by acetonitrile and determined with RP-HPLC and ultraviolet detection.the analytical column was Intertsil C18 column((4.6) mm?250 mm,5 ?m).The mobile phase consisted of methanol:H_2O(5050),the detection wavelength was 215 nm and the flow rate was(1.4)(ml?min~(-1)),the column temperature was 20 ℃,the sensitivity was 0.02AUFS respectively.The volume of sample for detection is 10 ?l.RESULTS:The linear range was(0.1)-25(?g?ml~(-1))(r=(0.9992)). The recovery of ropivacaine was(91.2)%-(93.6)%,RSD was(2.10)%-(3.40)%(n=6).The detection limit was(0.05)(?g?ml~(-1)).the intra-day and interday precisions of assay for ropivacaine was(1.35)%-(2.88)% and(1.80)%-(3.76)%.The quantative analysis of ropivacaine in plasma was not interfered by impurities.CONCLUSION: The assay method was shown to be suitable for determination the concentration of ropivacaine in plasma.The method is simple,accurate,sensitive and reproducible.