A new type of instrument that called the rapid determination of carbon dioxide combining power without mercury is proposed. The performance of the instrument in accordance to the requirements in ISO15189 of laboratory accreditation has been evaluated. The results showed that, this instrument is safe, pollution-free, accurate and practical.
Carbon Dioxide ; analysis ; Clinical Chemistry Tests ; instrumentation ; Equipment Design

Objective: To explore the occupational hazards caused by three kinds of welding operations, and to provide data support for individual protection. Methods: In October 2020, the welding fumes, metal elements and welding arc generated by three welding operations of argon gas shielded welding (JS80 welding wire) , manual welding (ZS60A welding rod) and carbon dioxide shielded welding (907A flux cored wire) were collected and measured in the welding laboratory. The samples were analyze and compare in the laboratory, and the differences of the occupational hazard factors of the three welding operations were judged. Results: The concentration of welding fume produced by carbon dioxide shielded welding, manual welding (ZS60A electrode) , and argon gas shielded welding (JS80 welding wires) were 6.80 mg/m(3), 6.17 mg/m(3), and 3.13 mg/m(3), respectively. The effective irradiance of the welding arc outside the welding mask from high to low is manual welding (ZS60A electrode) , carbon dioxide shielded welding (907A flux-cored welding wire) , and argon shielded welding (JS80 welding wire) , respectively 1 010.7, 740.9, 589.5 μW/cm(2). The long-wave ultraviolet UVA intensity generated by argon shielded welding (JS80 welding wire) is the largest, which is 1 500 μW/cm(2). The content of Mn in the three welding operations is the highest, and JS80 welding wire has the highest Mn content of 128493.2 mg/kg. 907A flux cored wire has the highest Ti content, which is 24355.5mg/kg. The electrode ZS60A has the highest Cu content, which is 24422.12 mg/kg. Conclusion: The intensity of occupational hazards is different in the three kinds of welding operations, so the methods of personal protective equipment, field exposure assessment and health monitoring should be more targeted.
Air Pollutants, Occupational/analysis* ; Argon/analysis* ; Carbon Dioxide/analysis* ; Gases/analysis* ; Occupational Exposure/analysis* ; Welding/methods*

OBJECTIVEThe study was designed to compare the combustion products of coal gas, liquefied petroleum gas and natural gas in relation to indoor air pollution.

METHODSRegular pollutants including B(a)P were monitored and 1-hydroxy pyrene were tested in urine of the enrolled subjects. Radon concentrations and their changes in four seasons were also monitored in the city natural gas from its source plant and transfer stations to final users. To analyze organic components of coal gas, liquefied petroleum gas and natural gas, a high-flow sampling device specially designed was used to collect their combustion products, and semi-volatile organic compounds contained in the particles were detected by gas chromatograph-mass spectrograph (GC/MS).

RESULTSFindings in the study showed that the regular indoor air pollutants particles and CO were all above the standard in winter when heating facilities were operated in the city, but they were lowest in kitchens using natural gas; furthermore, although NO2 and CO2 were slightly higher in natural gas, B(a)P concentration was lower in this group and 1-hydroxy pyrene was lowest in urine of the subjects exposed to natural gas. Organic compounds were more complicated in coal gas and liquefied petroleum gas than in natural gas. The concentration of radon in natural gas accounted for less than 1% of its effective dose contributing to indoor air pollution in Beijing households.

CONCLUSIONCompared to traditional fuels, gases are deemed as clean ones, and natural gas is shown to be cleaner than the other two gases.

Air Pollution, Indoor ; analysis ; Carbon Dioxide ; analysis ; Coal ; Gas Chromatography-Mass Spectrometry ; Incineration ; Nitrogen Dioxide ; analysis ; Petroleum ; Radon ; analysis ; Volatilization

AIMTo explore the adapting metabolic mechanisms of the plateau zokors to the hypoxic-hypercapnic environment.

METHODSThe activities of lactate dehydrogenase in serum and tissues, and the content of lactate in serum of plateau zokors in spring, summer and autumn were determined by using method of enzyme analysis. The spectrums of lactate dehydrogenase isoenzymes in serum and tissues of plateau zokors in spring, summer and autumn were analyzed by using method of the discontinuous systemic poly-acrylamide perpendicular plank gel electrophoresis.

RESULTSThe activities of lactate dehydrogenase in serum had obvious seasonally difference that were higher in spring and lower in autumn, and the content of lactate in serum showed same changing pattern. The spectrums of lactate dehydrogenase isoenzymes in serum showed five bands that were LDH1, LDH2, LDH3, LDH4 and LDH5 from positive pole to negative pole respectively, it showed clearly two bands in serum of summer that were LDH4 and LDH5 and one band in serum of autumn that was LDH5. The activities of LDH in tissues of skeleton muscle, cardiac muscle and brain were higher compared with the other tissues, it decreased markedly from spring to summer to autumn. In tissues of liver, kidney and lungs, activities of LDH were lower. Activities of LDH in livers, were significantly higher in spring compared that in summer and autumn, which had no obvious difference between summer and autumn. Activities of LDH in kidneys and lungs, showed no obviously difference between spring and summer, which decreased markedly in autumn. The spectrums of lactate dehydrogenase isoenzymes in tissues of cardiac muscle, liver, lungs, kidney, brain and skeleton muscle showed five bands, the spectrums were obvious different in different tissues, and the content of LDH isoenzymes showed seasonal changes in different tissues.

CONCLUSIONGlycolysis levels in plateau zokors had obvious seasonally change which increased in spring and decreased in autumn significantly. It related to the activity of plateau zokors in different seasons and seasonal fluctuation of oxygen and carbon dioxide in burrows of plateau zokors.

Animals ; Carbon Dioxide ; metabolism ; Isoenzymes ; analysis ; metabolism ; L-Lactate Dehydrogenase ; analysis ; metabolism ; Rodentia ; metabolism ; Seasons

At present, the death cases of simple asphyxiant gas acute poisoning are increasing sharply. Common asphyxiant gases in death cases include nitrogen, helium, carbon dioxide, methane, propane, laughing gas, etc. Simple asphyxiant gas has no affinity for biological matrices and escapes quickly, which puts forward new requirements for autopsy procedures, selection and collection of samples, laboratory analysis and identification. This paper reviews the research and development process of death cases caused by simple asphyxiant gas acute poisoning and put forwards the collection and analysis strategy of the samples in such cases. The most valuable biological samples in such cases should be lung tissues associated with the airways, followed by brain tissue and cardiac blood. Gaseous samples from the esophageal cavity, tracheal cavity, pulmonary bronchi, gastric and cardiac areas are also recommended as valuable samples. In the case of postmortem examination, the gas should be injected into gas sample bag directly. Biological materials such as tissue and blood should be directly sealed in head-space vials and analyzed by using the headspace gas chromatography-mass spectrometry.
Carbon Dioxide/analysis* ; Autopsy ; Gas Chromatography-Mass Spectrometry ; Methane/analysis* ; Nitrogen

The safety and efficacy of the CO2laser as a replacement for the steel scalpel is well documented in plastic surgery, but the use of the laser blepharoplasty has been controversy. This study compares and contrasts the use of the CO2 laser with conventional method in cosmetic upper eyelid blepharoplasty. Thirteen Patients underwent blepharoplasty in a paired comparison study. Four patients(Group A) underwent blepharoplasty by laser, another four patients (Group B) underwent blepharoplasty by conventional method, and the other five patients(Group C) underwent upper eyelid blepharoplasty using the laser on one eye and a conventional method on the other side. Preoperative factor(set up time, equipment), intraoperative factor(actual operation time, bleeding, visibility), postoperative factor(swelling, ecchymosis, immediate & short term result) were evaluated. The advantage of using the CO2 laser rather than the steel scalpel in blepharoplasty are less bleeding and superior intraoperative visibility. The disadvantage of using the laser compared with steel scalpel include the cost of purchasing and maintaining the laser equipment, the need for additional and extensive laser training for surgeons and assistants, and the need for two assistants rather than the one needed for scalpel surgery There were no complications with either the scalpel or the laser.
Bleeding Time ; Blepharoplasty* ; Carbon Dioxide* ; Carbon* ; Ecchymosis ; Eyelids* ; Hemorrhage ; Humans ; Lasers, Gas* ; Matched-Pair Analysis ; Steel ; Surgery, Plastic

One hundred patients with hyperventilation syndrome presenting to emergency department(ED) were studied. Those were diagnosed on clinical basis by emergency medical physician. The male to female ratio was 15 : 85. In monthly distribution, the numbers of patients were increased during the two months, June and July. The 41% of patients visited the emergency center from 9:00 p.m. to 3:00 a.m.. The most common predisposing factors were the domestic problems, especially those between husband and wife(37%). Presenting complaints were dyspnea(34), paresthesia(30), muscle spasm(24), dizziness(6) and palpitation(6 patients). The initial examination of the patients in the ED were as follows, systolic blood pressure(134+/-7.15mmHg), heart rate(87.67+/-14.34/minute), respiratory rate(22.21+/-3.34/minute) and body temperature(36.61+/-0.31 degrees C, n=98). Arterial blood gas analysis showed alkalemia(pH 7.51+/-0.09) and hypocapnia(PCO2 26.67+/-8.30mmHg). After emergency cares, including carbone dioxide re-breathing and antianxietics, most of the symptoms were disappeared. The mean duration of stay in ED was 3.27+/-0.23 hours. The most important considerations in diagnosis of hyperventilation syndrome was the patients's history and the effective management was carbon dioxide rebreathing for a few minutes and antianxietics.
Blood Gas Analysis ; Carbon ; Carbon Dioxide ; Causality ; Diagnosis ; Emergencies* ; Emergency Service, Hospital* ; Female ; Heart ; Humans ; Hyperventilation* ; Male ; Spouses

This study was attempted to observe the rate of fall of arterial oxygen tension and the rate of rise of artetrial carbon dioxide tension after denitrogenation with 100%(Group I, n=10) or 50% oxygen(Group II, n=15) in 25 healthy ASA class I patients scheduled for ear, oromaxillary, head and orthopedic surgery that do not affect respiration or pulmonary function. After 30 minutes of denitrogenation under supine position, apnea was carried out by dis- connecting the endotracheal tube and rebreathing circuit until arterial oxygen saturation decreased to 90-95% by pulse oximetry which was placed at index finger. We calculated the mean rate of decrease of arterial oxygen tension (PaO2(tn)-PaO2(tn+1)) and the mean rate of increase of arterial carbon dioxide tension (PaCO2(tn+1)-PaCO2(tn)) minute by minute by arterial blood gas analysis. The results are as follows. 1) The mean rate of decrease of arterial oxygen tension after apnea was 40.96+/-11.02 in Group I and 43.22+/-5.49 mmHg/min. in Group II 2) The rate of increase of arterial carbon dioxide tension during the first one minute of apnea was 5.94+/-0.85 in Group I and 5.56+0.64 mmHg in Group II 3) The mean rate of increase of arterial carbon dioxide tension after first one minute was 2.46+/-0.78 in Group I and 2.47+/-0.71 mmHg/min. in Group II With the above results, we concluded that healthy human subject who was denitrogenated with 100% oxygen about 30 minutes can withstand apnea as far as 7 minutes, and those who denitrogenated with 50% oxygen can withstand apnea as far as 3 minutes without hypoxic insult.
Anesthesia* ; Anoxia ; Apnea* ; Blood Gas Analysis ; Carbon Dioxide* ; Carbon* ; Ear ; Fingers ; Head ; Humans ; Orthopedics ; Oximetry ; Oxygen* ; Respiration ; Supine Position

Most main oilfields in China have already entered a "double high" development stage (high water cut, high recovery degree). To further enhance oil recovery in reservoirs after polymer flooding (RAPFs), an efficient activator formulation for promoting metabolism of endogenous microorganism was studied by aerogenic experiments, physical simulation experiments, electron microscopy scanning and pyrophosphate sequencing. Results show that the activator could activate the endogenous microorganisms in the injected water and make the pressurized gas reach 2 MPa after 60 d static culture of the activator in a high pressure vessel. The oil recovery efficiency of natural core physical simulation flooding can be improved by more than 3.0% (OOIP) in RAPFs when injected 0.35 PV activator with 1.8% mass concentration, and a lot of growth and reproduction of activated endogenous microorganism in the core was observed by electron microscopy scanning. Field trial with 1 injector and 4 producers was carried out in the east of south II block of Sa Nan in December 2011. By monitoring four effective production wells, changes of carbon isotope δ13C (PDB) content of methane and carbon dioxide were -45 per thousand to -54 per thousand and 7 per thousand to 12 per thousand. Compared with east II of Sa Nan block, the oil amount increased by 35.9%, water cut stabled at 94%. The incremental oil was 5 957 t during the three and a half years, which provides an alternative approach for further improving oil recovery in similar reservoirs.
Carbon Dioxide ; chemistry ; Carbon Isotopes ; analysis ; China ; Diphosphates ; chemistry ; Methane ; chemistry ; Oil and Gas Fields ; microbiology ; Polymers ; Water ; Water Microbiology

Blood gas analysis are highly susceptible to preanalytic error due to improper method of obtaining or handling the sample before analysis. To study the effect of air bubbles and time delay in estimation of blood gas, the samples were divided 3 groups, according to the method of stroage and the existence of air bubble, group 1, stored at 25+/-2C(room temperature) under anaerobic condition; group 2, stored at 0-4 degrees C(refrigerator) under anaerobic condition, group 3, stored at 0-4 degrees C under aerobic condition(10% air in blood). The samples were analyzed by time interval through 180 minutes in each group. The results were as follows: 1) Oxygen partial pressure decreased significantly after 20 minutes in group 2, whereas decreased significantly after 10 minutes in group 1 & group 3. 2) Carbon dioxide partial pressure increased significantly after 120 minutes in gorup 2 and 60 minutes in group 3, whereas decreased after 10 minutes in group l. 3) Blood pH decreased significantly after 60 minutes in all three Rroups. 4) Arterial oxygen saturation decreased significantly after 30 minutes in Rroup 1, 60 minutes in group 2 and 10 minutes in group 3. 5) Bicarbonate changes were not significant in all three groups clinically. From the above results, it is assumed that arterial blood samples should be analyzed whithin 10 minutes or cooled immediately.
Blood Gas Analysis ; Carbon Dioxide ; Hydrogen-Ion Concentration ; Oxygen ; Partial Pressure