Improving the Laser-Induced Breakdown Spectroscopy for Highly Efficient Trace Measurement of Hazardous Components in Waste Oils.

Improper disposal of waste oils containing hazardous components damages the environment and the ecosystem, posing a significant threat to human life and health. Here, we present a method of discharge-assisted laser-induced breakdown spectroscopy combined with filter paper sampling (DA-LIBS-FPS) to detect hazardous components and trace the source of polluting elements. DA-LIBS-FPS significantly enhances spectral intensity by 1-2 orders of magnitude due to the discharge energy deposition into the laser-induced plasma and the highly efficient laser-sample interaction on the filter paper, when compared to single-pulse LIBS with silica wafer sampling (SP-LIBS-SWS). Additionally, the signal-to-noise ratio and the signal-to-background ratio are both significantly increased. Resultantly, indiscernible lines, such as CN and Cr I, are well distinguished. In contrast with DA-LIBS combined with silica wafer sampling (DA-LIBS-SWS), the spectral signal fluctuations in DA-LIBS-FPS are reduced by up to 33%, because of the homogeneous distribution of the oil layer on the filter paper in FPS. Further examination indicates that the limit of detection for Ba is reduced from a several parts per million level in SP-LIBS-SWS to a dozens of parts per billion level in DA-LIBS-FPS, i.e., nearly 2 orders of magnitude enhancement in analysis sensitivity. This improvement is attributed to the extended plasma lifespan in DA-LIBS and the increasing electron density and plasma temperature in FPS. DA-LIBS-FPS provides a low-cost, handy, rapid, and highly sensitive avenue to analyze the hazardous components in waste oils with great potential in environmental and ecological monitoring.

Characterization of the laser-induced breakdown spectroscopy near the gas-liquid two-phase interface.

The characterization of laser-induced breakdown spectroscopy (LIBS) near the gas-liquid two-phase interface was investigated with the laser acting on the sample along the horizontal direction. Simulation of the laser beam focusing process and observation of laser beam spot images show that difference in focusing positions in the air and the solution results from refraction of the laser beam entering the solution from the air and the change of propagation direction on the container lateral. The peak power and mean irradiance of the focused laser beam spot increase with the distance away from the interface, which is attributed to the fact that the loss of laser energy due to the refraction and reflection of light at the interface decreases with the focusing position moving away from the interface. This variation trend of laser irradiance allows for the growth of the spectral line intensity and lifetime with increasing the distance from the interface. The plasma electron density and temperature decrease with the delay time but increase with the distance away from the interface at the same delay time. Our findings help us to gain more insight into the characteristics and evolution mechanisms of LIBS produced near the gas-liquid two-phase interface, which provides theoretical guidance for the correction of LIBS spectra especially in water pollution monitoring.

Time-resolved characteristics of laser induced breakdown spectroscopy on non-flat samples by single beam splitting.

A single-beam-splitting approach was used to enhance the signal intensity of LIBS under the extreme conditions of laser beam grazing of the surface of non-flat samples. Time-resolved spectra show that the laser-ablated plasma presents a stronger spectral intensity and a slower plasma decay in the split beam mode because of the higher laser irradiance. The temporal evolutions of signal enhancement factors indicate that the enhancement effect first rises and then drops with delay time and the maximum enhancement factor of Al plasma comes later than that of Cu plasma under the same laser energy. The mechanisms behind it are discussed. It is also found that the electron density exhibits a faster decay with delay time in the split beam mode, mainly due to the faster plasma expansion. And a slower increase of electron density with laser energy is observed in the split beam mode because of the plasma shielding effect.

[Research on pollution load of sediments in storm sewer in Beijing district].

Based on the investigation of sewer sediments in Xi Cheng district in Beijing, scour-release pollution load in one rainfall from sewer sediments was studied by monitoring the pollutants in the run-off of manhole's section. It was shown that the contribution of scour-release pollutants from sewer sediments to sewer outflow was obvious. The contribution rate of the sediments pollution load to runoff outflow in the 84 m pipeline in one rainfall (9 Jul., 2010) was as follows: TN 8.5%, TP 8.2%, COD 18.3%, SS 7.7%, respectively. And the pollutant contribution rate in the 295 m pipeline in another rainfall (4 Aug., 2010) was TN 23.12%, TP 60.01%, COD 33.78%, SS 31.89%. Therefore, it is important to control the pollution from sewer sediments for the improvement of water environment.

[Clinical observation on prevention of "jia wei si jun zi tang" from damage of hepatic reserving function after intervention of liver cancer].

OBJECTIVE: To observe prevention of "Jia Wei Si Jun Zi Tang" (JWSJZT) from damage of hepatic reserving function after intervention of liver cancer. METHODS: 65 patients with advance stage of liver cancer were randomly into two groups, the control group (regular protective therapy) and the treatment group (regular protective therapy + JWSJZT). There were 33 and 32 cases in the control group and treatment group,respectively. ICGR15 was detected before the first and the second intervention treatment and one month after the second intervention treatment, respectively. ICGR15 change was observed before and after the intervention treatment in the two groups. RESULTS: ICGR15 was 11.13% +/- 7.28% in the treatment group and 11.81% +/- 7.43% in the control group (P > 0.05) before the first intervention; 18.36% +/- 9.82% in the control group and 12.18% +/- 5.22% in the treatment group, before the second invention treatment (P < 0.05); 19.12% +/- 9.96% in the control group and 12.83% +/- 5.28% in the treatment group one month after the second intervention treatment (P < 0.05). CONCLUSION: The western medicine + JWSJZT group is superior in curative effect to western medicine group.

[Clinical study in prophylactic use of chinese medicine to prevent chemoradiotherapy induced mucositis in nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Oropharyngeal mucositis is the most common acute non-hematology toxicity in nasopharyngeal carcinoma (NPC) treated with radiotherapy, especially in the concomitant chemoradiotherapy of local advanced NPC patients. This study was designed to observe the effect of traditional Chinese medicine against acute oropharyngeal mucositis from chemoradiotherapy in patients with local advanced NPC. METHODS: A total of 101 patients in stage III- IVa (Fuzhou 1992) were enrolled into this prospective randomized clinical trial. The cases were divided into treatment group (52 cases) and control group (49 cases). The median doses were 70.31+/-1.21 Gy for the treatment group and 70.78+/-1.95 Gy for the control group, respectively. Chemotherapy was concomitant with radiotherapy [single agent cisplatin (DDP,30 mg/m(2)) 6 times from first to sixth week of radiotherapy duration]. The patients of treatment group took 5-8 times of Chinese medicine daily and those of control group took 5-8 times of Dobell's solution daily.The observation indices included the degree of oropharyngeal and hematological toxicity, radiotherapy duration, and curative effect. RESULTS: (1)Oropharyngeal toxicity: there was no 0 degree oropharyngeal toxicity in both groups, I degree toxicity in 29 cases (55.77%) and 2 cases (4.08%), II degree toxicity in 18 cases (34.62%) and 17 cases (30.69%), III degree toxicity in 5 cases (9.62%) and 22 cases (44.89%), IV degree toxicity in 0 case (0%) and 8 cases (16.33%); there was statistical significance of difference between the two groups (P=0.000). (2)Hematological toxicity: there was no IV degree hematological toxicity in both groups. WBC toxicity (Z=-0.604,P=0.546), neutrophilic granulocyte toxicity (Z=-0.226,P=0.821), and platelet toxicity (Z=-0.099,P=0.922) were compared; there was no statistic significance of difference (P >0.05); (3)Radiotherapy duration: The radiotherapy duration of two groups were 49.79+/-1.83 days and 51.00+/-4.46 days; there was no statistic significance of difference (P=0.082). (4)Curative effects: The curative effects of two groups were:complete remission (CR) 76.92% (40/52) and 69.39% (34/49), partial remission (PR) 23.08% (12/52) and 30.61% (15/49); there was no statistical significance of difference (P=0.392). CONCLUSION: Chinese medicine was effective in reducing acute oropharyngeal toxicity resulting from chemoradiotherapy in patients with local advanced NPC. Furthermore, the apparent side effects of Chinese medicine in this study have not been observed. Chinese medicine treatment did not affect the short-term clinical outcome.

[Study on prevention and treatment of radiotherapy caused post-visual pathway injury in nasopharyngeal carcinoma patients by traditional Chinese medicine].

OBJECTIVE: To study the effect of TCM in preventing and treating post-visual pathway injury caused by radiotherapy (RT) for nasopharyngeal carcinoma (NPC). METHODS: Thirty-five patients of NPC were randomly divided into the RT group (n = 17) and the RT + TCM group (n = 18), they were all received RT, but the latter was treated additionally with Jingming recipe, a Chinese recipe. The latent period and amplitude of evoked potential (EP) were measured before and after ending of RT, using multi-focusing visual evoked potential inspector. RESULTS: The latent time of EP, both upper and lower visual field, was prolonged significantly after RT in the RT group (P < 0.05), but not in the RT + TCM group (P > 0.05); the amplitude of EP of upper visual field lowered significantly (P < 0.05) in the RT group but insignificantly in the RT + TCM group (P > 0.05); as for the EP amplitude of lower visual field, it was unaltered in RT group after RT (P > 0.05), but increased in the RT + TCM group (P < 0.05). CONCLUSION: The Chinese medicine Jingming recipe was effective in preventing and treating RT induced post-visual pathway injury.

[Treatment of hepatic functional reserve injury after TACE in hepatocellular carcinoma with Chinese herbal medicines].

BACKGROUND & OBJECTIVE: Transcatheter arterial chemoembolization (TACE) has been proved to injure hepatic functional reserve. The current study was designed to evaluate the effect of Chinese herbal medicines in treatment of hepatic functional reserve injury after TACE. METHODS: Sixty-one advanced hepatocellular carcinoma patients were divided into two groups: groups A (Western medicine combined with Chinese herbal medicine group, n = 30) and group B (Western medicine group, n = 31). Western medicines were used to protect hepatic function and alleviate TACE syndrome in both group A and group B. Invigorating the spleen and activating blood circulation Chinese herbal medicines were added only in group A before and after TACE. Retention rate of Indocyanine green at 15 minutes (ICGR15) was measured in both group A and group B before 1st, 2nd TACE and one month after 2nd TACE respectively. RESULTS: Hepatic functional reserve before 1st TACE was 11.18% +/- 7.30% in group A and 11.83 +/- 7.18% in group B, (P > 0.05). Hepatic functional reserve before 2nd TACE was 11.69% +/- 5.13% in group A and 16.64 +/- 10.15% in group B, (P < 0.05). Hepatic functional reserve one month after 2nd TACE was 11.53% +/- 5.30% in group A and 19.80 +/- 11.26% in group B, (P < 0.05). CONCLUSIONS: Invigorating the spleen and activating blood circulation Chinese herbal medicine can prevent hepatic functional reserve injury after TACE.