Giant bile duct dilatation in newborn: A case report.

BACKGROUND: Giant congenital biliary dilation (CBD) is a rare condition observed in clinical practice. Infants born with this condition often experience a poor overall health status, and the disease progresses rapidly, leading to severe biliary obstruction, infections, pressure exerted by the enlarged CBD on abdominal organs, disturbances in the internal environment, and multiple organ dysfunction. The treatment of giant CBD using laparoscopy is challenging due to the high degree of variation in the shape of the bile duct and other organs, making it difficult to separate the bile duct wall from adjacent tissues or to control bleeding. CASE SUMMARY: Herein, we present the details of an 11-d-old male newborn who was diagnosed with giant CBD. The patient was admitted to the neonatal surgery department of our hospital due to a history of common bile duct cyst that was detected more than 3 mo ago, and also because the patient had been experiencing yellowish skin for the past 9 d. The abnormal echo in the fetal abdomen was first noticed by the patient's mother during a routine ultrasound examination at a local hospital, when the patient was at 24 wk + 6 d of pregnancy. This finding raised concerns about the possibility of congenital biliary dilatation (22 mm × 21 mm). Subsequent ultrasound examinations at different hospitals consistently confirmed the presence of a congenital biliary dilatation. No specific treatment was administered for biliary dilatation during this period. A computed tomography scan conducted during the hospitalization revealed a large cystic mass in the right upper quadrant and pelvis, measuring approximately 9.2 cm × 7.4 cm × 11.3 cm. Based on the scan, it was classified as a type I biliary dilatation. CONCLUSION: The analysis reveals that prenatal imaging techniques, such as ultrasound and magnetic resonance imaging, play a crucial role in the early diagnosis, fetal prognosis, and treatment plan for giant CBD. Laparoscopic surgery for giant CBD presents certain challenges, including difficulties in separating the cyst wall, anastomosis, and hemostasis, as well as severe biliary system infection and ulceration. Consequently, there is a high likelihood of converting to laparotomy. The choice between surgical methods like hepaticojejunostomy (HJ) or hepaticoduodenostomy has not been standardized yet. However, we have achieved favorable outcomes using HJ. Preoperative management of inflammation, biliary drainage, liver function protection, and supportive treatment are particularly vital in improving children's prognosis. After discharge, it is essential to conduct timely reexamination and close follow-up to identify potential complications.

Development and preliminary validation of Cancer-related Psychological Flexibility Questionnaire.

The Cancer-related Psychological Flexibility Questionnaire (CPFQ) was developed and validated for assessing cancer patients' psychological flexibility, including attitudes and behavior toward cancer. In a systematic process, the CPFQ identified four factors through principal component analysis and confirmatory factor analysis: Cancer Acceptance, Cancer Avoidance, Activity Engagement, and Valued Action. The results of this study reveal that the CPFQ has a clear factor structure and good psychometric properties. The specific nature of cancer and the need for a specific measure of cancer patient psychological flexibility make this questionnaire valuable for research on psychological flexibility in cancer patients.

Esophageal magnetic compression anastomosis in dogs.

BACKGROUND: Magnetic compression anastomosis (MCA) is a novel suture-free reconstruction of the digestive tract. It has been used in gastrointestinal anastomosis, jejunal anastomosis, cholangioenteric anastomosis and so on. The traditional operative outcomes of congenital esophageal atresia and benign esophageal stricture are poor, and there are too many complications postoperatively. AIM: To test MCA technology to reconstruct the esophagus in dogs, prior to studying the feasibility and safety of MCA in humans. METHODS: Thirty-six dogs were randomized into either the study or control group (n = 18 per group). The dogs in the study group were subjected to end-to-end esophageal anastomosis with the magnetic compression device, while those in the control group underwent hand-sewn anastomosis with 4-0 absorbable multifilament Vicryl. We used interrupted single-layer inverting sutures. The anastomosis time, gross appearance, weight and pathology of the anastomosis were evaluated at one month, three months and six months postoperatively. RESULTS: The anastomosis time of the MCA group was shorter than that of the hand-sewn group (7.5 ± 1.0 min vs 12.5 ± 1.8 min, P < 0.01). In the MCA group, X-ray examination was performed every day to locate the magnetic device in the esophagus before the magnetic device fell off from the esophagus. In the hand-sewn group, dogs did not undergo X-ray examination. One month after the surgeries, the mean weight of the dogs in the hand-sewn group had decreased more than that of the dogs in the MCA group (11.63 ± 0.71 kg vs 12.73 ± 0.80 kg, P < 0.05). At 3 mo and 6 mo after the operation, the dogs' weights were similar between the two groups (13.75 ± 0.84 kg vs 14.03 ± 0.82 kg, 14.93 ± 0.80 kg vs 15.44 ± 0.47 kg). The number of inflammatory cells in MCA group was lower than that in hand-sewn group on 1 mo after operation. CONCLUSION: MCA is an effective and safe method for esophageal reconstruction. The anastomosis time of the MCA group was less than that of the hand-sewn group. This study shows that MCA technology may be applied to human esophageal reconstruction, provided these favorable results are confirmed by more publications.

Chinese Version of the Psychological Inflexibility in Pain Scale for Cancer Patients Reporting Chronic Pain.

BACKGROUND: Cancer-related chronic pain is reported by many patients during treatment. There are very few Chinese tools for measuring psychological inflexibility caused by cancer pain, particularly with regard to psychological processes that might influence pain severity and function disorder during cancer treatment. OBJECTIVE: To culturally adapt the Psychological Inflexibility in Pain Scale (PIPS) to Chinese cancer patients experiencing chronic pain, including the determination of psychometric properties of the translated PIPS. METHODS: This cross-sectional study included 2 phases: (1) translation and cultural adaptation and (2) determination of psychometric properties of the translated PIPS. In total, 389 cancer patients with several types of cancer experiencing chronic pain enrolled from May to September 2018 at a tertiary cancer hospital in Yuelu District of Hunan Province, China. RESULTS: The Chinese PIPS version was semantically equivalent to the original. It had a 2-factor structure with satisfactory content validity (content validity index = 0.78-1.00), convergent and discriminant validity (composite reliability and average variance extracted at 0.41-0.89, P < .001), criterion-related validity (r = 0.54 and 0.41, P < .001), Cronbach's α coefficients (α = .87), and test-retest reliability (0.9 ≤ r ≤ 0.98). CONCLUSIONS: The Chinese PIPS version has been culturally adapted and has strong psychometric properties. The scale is a psychometrically sound assessment of psychological inflexibility that can be used for future studies of pain and pain management for cancer patients. IMPLICATIONS FOR PRACTICE: The study provides a vital tool for the psychological management of cancer patients with chronic pain.

Study on gene expression patterns and functional pathways of peripheral blood monocytes reveals potential molecular mechanism of surgical treatment for periodontitis.

BACKGROUND: Periodontitis is a chronic inflammation of periodontal supporting tissue caused by local factors. Periodontal surgery can change the gene expression of peripheral blood mononuclear cells. However, little is known about the potential mechanism of surgical treatment for periodontitis. AIM: To explore the potential molecular mechanism of surgical treatment for periodontitis. METHODS: First, based on the expression profiles of genes related to surgical treatment for periodontitis, a set of expression disorder modules related to surgical treatment for periodontitis were obtained by enrichment analysis. Subsequently, based on crosstalk analysis, we proved that there was a significant crosstalk relationship between module 3 and module 5. Finally, based on predictive analysis of multidimensional regulators, we identified a series of regulatory factors, such as endogenous genes, non-coding RNAs (ncRNAs), and transcription factors, which have potential regulatory effects on periodontitis. RESULTS: A total of 337 genes related to surgical treatment for periodontitis were obtained, and 3896 genes related to periodontitis were amplified. Eight expression modules of periodontitis were obtained, involving the aggregation of 2672 gene modules. These modules are mainly involved in G-protein coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger, and adenylate cyclase-modulating G-protein coupled receptor signaling pathway. In addition, eight endogenous genes (including EGF, RPS27A, and GNB3) were screened by network connectivity analysis. Finally, based on this set of potential dysfunction modules, 94 transcription factors (including NFKB1, SP1, and STAT3) and 1198 ncRNAs (including MALAT1, CRNDE, and ANCR) were revealed. These core regulators are thought to be involved in the potential molecular mechanism of periodontitis after surgical treatment. CONCLUSION: Based on the results of this study, we can show biologists and pharmacists a new idea to reveal the potential molecular mechanism of surgical treatment for periodontitis, and provide valuable reference for follow-up treatment programs.

Magnetic Anastomosis Rings to Create Portacaval Shunt in a Canine Model of Portal Hypertension.

PURPOSE: This study evaluated a novel magnetic compression technique (magnamosis) for creating a portacaval shunt in a canine model of portal hypertension, relative to traditional manual suture. METHODS: Portal hypertension was induced in 18 dogs by partial ligation of the portal vein (baseline). Six weeks later, extrahepatic portacaval shunt implantation was performed with either magnetic anastomosis rings, or traditional manual suture (n = 9, each). The two groups were compared for operative time, portal vein pressure, and serum biochemical indices. Twenty-four weeks post-implantation, the established anastomoses were evaluated by color Doppler imaging, venography, and gross and microscopic histological examinations. RESULTS: Anastomotic leakage did not occur in either group. The operative time to complete the anastomosis for magnamosis (4.12 ± 1.04 min) was significantly less than that needed for manual suture (24.47 ± 4.89 min, P < 0.01). The portal vein pressure in the magnamosis group was more stable than that in the manual suture group. The blood ammonia level at the end of the 24-week post-implantation observation period was significantly lower in the magnamosis group than in the manual suture group. Gross and microscopic histological examinations revealed that better smoothness and continuity of the vascular intima had been achieved via magnamosis than with manual suture. CONCLUSION: Magnamosis was superior to manual suture for the creation of a portacaval shunt in this canine model of portal hypertension.

Brief Introduction of Medical Insurance System in China.

China has one of the largest numbers of cancer patients. The huge expenses of medical care for cancer patients has brought heavy economic burden to the family. This paper briefly introduces the tumor medical insurance situation in China from the construction and composition of China's medical security system, the access of cancer patients to get health insurance, the challenges and developmental trend of China's medical security system, and two case studies that highlight different financial situations.

Electron Donor Substances and Iron Oxides Stimulate Anaerobic Dechlorination of DDT in a Slurry System with Hydragric Acrisols.

The interactive effects between electron donor substances and iron (Fe) oxides have significant influence on electron transfer and the growth of Fe-reducing bacteria, which may affect the reductive dechlorination of 1,1,1-trichoro-2,2-bis(p-chlorophenyl)ethane (DDT) in soils. To evaluate the roles of volatile fatty acids and Fe(III) oxide in accelerating the reductive dechlorination of DDT in Hydragric Acrisols, a batch anaerobic incubation experiment was conducted in a slurry system with the following seven treatments: sterile soil, control (DDT-contaminated soil), lactic acid, propionic acid, goethite, lactic acid + goethite, and propionic acid + goethite. Results showed that after 20 d of incubation, DDT residues for these treatments decreased by 34, 65, 77, 81, 77, 90, and 92% of the initial quantities, respectively, with 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane as the dominant metabolite. The application of lactic acid had no significant effect on DDT dechlorination in the first 8 d while the methanogenesis rate increased quickly but accelerated DDT dechlorination after Day 8 while the methanogenesis rate decreased and Fe(II) contents increased. The application of propionic acid enhanced DDT dechlorination rates throughout the incubation. The amendment by goethite stimulated microbial reduction of Fe(III) oxides to generate Fe(II), which was an efficient electron donor, thus accelerating DDT dechlorination significantly in the early incubation period. A synergetic interaction that accelerated DDT dechlorination, either between lactic acid and goethite or between propionic acid and goethite, was obtained. The results will be of great significance to develop efficient in situ remediation technology of DDT-contaminated soil.

Evidence for anaerobic ammonium oxidation process in freshwater sediments of aquaculture ponds.

The anaerobic ammonium oxidation (anammox) process, which can simultaneously remove ammonium and nitrite, both toxic to aquatic animals, can be very important to the aquaculture industry. Here, the presence and activity of anammox bacteria in the sediments of four different freshwater aquaculture ponds were investigated by using Illumina-based 16S rRNA gene sequencing, quantitative PCR assays and (15)N stable isotope measurements. Different genera of anammox bacteria were detected in the examined pond sediments, including Candidatus Brocadia, Candidatus Kuenenia and Candidatus Anammoxoglobus, with Candidatus Brocadia being the dominant anammox genus. Quantitative PCR of hydrazine synthase genes showed that the abundance of anammox bacteria ranged from 5.6 × 10(4) to 2.1 × 10(5) copies g(-1) sediment in the examined ponds. The potential anammox rates ranged between 3.7 and 19.4 nmol N2 g(-1) sediment day(-1), and the potential denitrification rates varied from 107.1 to 300.3 nmol N2 g(-1) sediment day(-1). The anammox process contributed 1.2-15.3% to sediment dinitrogen gas production, while the remainder would be due to denitrification. It is estimated that a total loss of 2.1-10.9 g N m(-2) per year could be attributed to the anammox process in the examined ponds, suggesting that this process could contribute to nitrogen removal in freshwater aquaculture ponds.

[Mechanism of manganese binding to leaf cell wall of Phytolacca americana L].

Phytolacca americana L. (P. americana) is a manganese (Mn) hyperaccumulator and cell wall plays an important role in the accumulation and detoxicity of Mn. We studied the impact of pH and Mn initial concentration on the binding of Mn by the leaf cell wall of P. americana, and explored the binding mechanisms by Fourier Transform Infrared Spectroscopy (FTIR) and synchrotron-based X-ray Absorption Fine Structure (XAFS) Spectroscopy. The results show that the optimum pH of Mn bingding for the leaf cell wall is between 5 and 6. The adsorption behavior of leaf cell wall can be described by Langmuir equation (R2 = 0.978 5) and the maximum adsorption of Mn on the leaf cell wall is 62.50 µmol x g(-1). Hydronyl and carbonyl groups are involved in the binding of Mn on the leaf cell wall. The Mn absorbed on the leaf cell wall is bonded by 6.3 oxygen around, and the bond length of Mn-O is 0.216 nm, which indicates the binding mechasnism of Mn to cell wall was inner-sphere complexation.

Occurrence and importance of anaerobic ammonium-oxidising bacteria in vegetable soils.

The quantitative importance of anaerobic ammonium oxidation (anammox) has been described in paddy fields, while the presence and importance of anammox in subsurface soil from vegetable fields have not been determined yet. Here, we investigated the occurrence and activity of anammox bacteria in five different types of vegetable fields located in Jiangsu Province, China. Stable isotope experiments confirmed the anammox activity in the examined soils, with the potential rates of 2.1 and 23.2 nmol N2 g(-1) dry soil day(-1), and the anammox accounted for 5.9-20.5% of total soil dinitrogen gas production. It is estimated that a total loss of 7.1-78.2 g N m(-2) year(-1) could be linked to the anammox process in the examined vegetable fields. Phylogenetic analyses showed that multiple co-occurring anammox genera were present in the examined soils, including Candidatus Brocadia, Candidatus Kuenenia, Candidatus Anammoxoglobus and Candidatus Jettenia, and Candidatus Brocadia appeared to be the most common anammox genus. Quantitative PCR further confirmed the presence of anammox bacteria in the examined soils, with the abundance varying from 2.8 × 10(5) to 3.0 × 10(6) copies g(-1) dry soil. Correlation analyses suggested that the soil ammonium concentration had significant influence on the activity and abundance of anammox bacteria in the examined soils. The results of our study showed the presence of diverse anammox bacteria and indicated that the anammox process could serve as an important nitrogen loss pathway in vegetable fields.

[Combined stress of enhanced UV-B radiation and 1,2,4-trichlorobenzene contamination on the growth of green vegetable].

A pot experiment was conducted to study the effects of UV-B radiation enhancement alone, 1,2,4-trichlorobenzene (TCB) contamination soil alone, and the combined stress on the growing process, stomatal resistance and leaf structure of green vegetable. The results showed that 1,2,4-TCB contamination alone had more significant inhibitory effect on the growth of green vegetable than the combined stress. Both UV-B radiation enhancement and 1,2,4-TCB contamination reduced the stomatal resistance of front and reverse leaves. Enhanced UV-B radiation resulted in the albino of leaves. 1,2,4-TCB contamination resulted in the fading of leaf color and the appearing of black spots on leaf surfaces, and the enhanced UV-B radiation strengthened the black-spot symptom. In conclusion, the effects of UV-B radiation enhancement alone, 1,2,4-trichlorobenzene (TCB) contamination soil alone and the combined stress on the growth indicators of green vegetable were different.

Heavy metal accumulation in balsam pear and cowpea related to the geochemical factors of variable-charge soils in the Pearl River Delta, South China.

Variable-charge (v-c) soils in subtropical areas contain considerable amounts of iron/aluminum (Fe/Al) oxides that can strongly influence the fate of heavy metals in agricultural ecosystems. However, the relationship between heavy metal accumulation in vegetables and the geochemical factors associated with v-c soils in subtropical regions remains unknown. The present study investigated heavy metal accumulation under field conditions in the Pearl River Delta (PRD) by measuring the content of 8 heavy metals (zinc (Zn), arsenic (As), copper (Cu), mercury (Hg), lead (Pb), chromium (Cr), nickel (Ni) and cadmium (Cd)) in 43 pairs of v-c soil and vegetable (balsam pear and cowpea) samples. Soil physicochemical properties including pH, texture, organic matter and oxide minerals (Fe2O3, SiO2, Al2O3, CaO, MgO, K2O and Na2O) were also analyzed. Heavy metal accumulation from soil to vegetables was assessed based on bioconcentration factors (BCFs). The results showed that soil extractable Fe, oxide minerals and chemical weathering indices of v-c soils strongly affected heavy metal accumulation, whereas the content of Zn, Cu, Cr and Ni in vegetables was strongly affected by the soil clay content. Significant correlations were found between the BCFs of heavy metals and oxide minerals. However, no significant relationship was found between pH and heavy metal accumulation (except for Cu) in balsam pear and cowpea. Correlation analyses showed that a lower oxalate/DCB- extractable Fe content might indicate greater heavy metal (Zn, Cu, Hg, Cr and Ni) accumulation in vegetables. Therefore, it can be deduced that oxalate/DCB- extractable Fe content is a critical geochemical factor that determines the bioavailability of heavy metals and that iron biogeochemical cycles play vital roles in the fate of heavy metals in vegetable fields in this area. These findings provide new insights into the behaviors and fate of heavy metals in subtropical v-c soils and can be used to develop possible guidelines for vegetable safety management.

[Influence of the interaction between iron oxide and electron donor substances on 1,1,1-trichloro- 2, 2-bis (p-chlorophenyl) ethane ( DDT) reductive dechlorination in hydragric acrisols].

The interaction between iron oxide and electron donor substance have significant influences on electron transfer and the growth of iron-reducing bacteria, which may affect the reductive dechlorination of polychlorinated organic compounds in soil. Anaerobic soil incubation experiment was conducted to study the effect and its mechanism of iron oxide (goethite), electron donor substances (butyrate and ethanol), and their interaction on DDT reductive dechlorination in Hydragric Acrisols. Results showed that after 6 weeks of anaerobic incubation, the extractable residues of DDT were between 1.29% and 2.01% of initial DDT amounts in soils, which was attributed to the dechlorinated degradation of DDT and formation of bound residues of DDT and its dechlorinated products. The main product of DDT anaerobic dechlorination was 1,1-dichloro-2,2-bis (p-chloro-phenyl) ethane (DDD). During the prophase of incubation, the application of butyrate or ethanol led to the decreased pH and increased Eh for reaction system, thus inhibited DDT dechlorination. The applications of only goethite or goethite and electron donor substances resulted in the increased soil pH, decreased soil Eh and increased Fe( II ) contents, thus accelerated DDT dechlorination. There was no significant interaction between butyrate and iron oxide on DDT dechlorination, whereas there was antagonistic action between ethanol and iron oxide on DDT dechlorination. The results will be of great significance for developing efficient and in-situ remediation technology of DDT contaminated soil.

[Study on regularity of greenhouse gas emissions from black soil with different reclamation years].

Regularity of greenhouse gas emissions from black soil with different reclamation years in northern China was investigated by an incubation experiment. Soil samples cultivated for 2 years, 30 years, 100 years and uncultivated were collected and incubated at 2 degrees C and a soil moisture of 60% of the water hold capacity (WHC) for 7 days. The results indicated that the physical and chemical properties of black soil changed significantly after reclamation, which had significant influence on the greenhouse gas emissions. N2O emission was stimulated after soil was reclaimed, the longer time of reclamation, the higher N2O emitted from soil, and the N2O emissions from soil cultivated for 30 and 100 years were significantly higher than that from uncultivated soil. There were significant positive correlations between N2O emission and the content of water organic nitrogen and silt in soil, whereas significant negative correlations were found between pH, sand content and N2O emission. CO2 emission decreased after the soil was cultivated, and CO2 emission from soil cultivated for 30 and 100 years were significantly lower than that of uncultivated soil. There were significant positive correlations between organic carbon, water organic carbon and CO2 emission. All of the soils behaved as weak sources of CH4 emission during the first 4 days of incubation, and then behaved as weak sink of atmospheric CH4, the CH4 cumulative emission increased with reclamation years. The difference of CO2 and CH4 emissions from black soil with different reclamation years may be attributed to the difference of soil pH, organic carbon, soluble organic carbon and the contents of sand and silt.

[Preliminary analysis of manganese uptake mechanism in the hyperaccumulator Phytolacca americana L].

Phytolacca americana L. (P. americana) is a manganese (Mn) hyperaccumulator plant discovered in southern China, and knowledge of Mn uptake characteristics and mechanisms on this plant may provide essential and critical information for phytoremediation. Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe was empolyed in this study to explore the Mn distribution in the root cross-section of P. americana, and effects of metabolic inhibitors (DNP and Na3VO4) and Ca-channel inhibitor (LaCl3) on Mn uptake of P. americana was also investigated under laboratory conditions. Results showed that P. americana has strong abilities for absorpting and accumulating Mn, and the Mn concentration in root, stem, and leaf of P. americana may reach up to 402, 208, and 601 mg x kg(-1) DW, respectively, even only treated with 5 micromol x L(-1) Mn. The highest Mn content can be found in the vascular bundle of root, and then the epidermis, while the lowest Mn content can be observed in the cortex. The Mn content increased when shifted from cortex to vascular bundle, indicating that there was an active transportation in Mn absorption of P. americana root, and the inhibitory effect of DNP and Na3VO4 on Mn uptake further verified the possibilities of active absorption. The Mn uptake was inhibited by 30% with LaCl3, suggesting that Mn uptake in P. americana also closely related to the Ca-channel.

Effects of calcium peroxide on arsenic uptake by celery (Apium graveolens L.) grown in arsenic contaminated soil.

The ability of calcium peroxide (CaO(2)) to immobilize As of contaminated soil was studied using pot and field experiments. In pot experiment, CaO(2) applied at 2.5 and 5 g kg(-1) significantly increased celery shoot weight and decreased shoot As accumulation, which was ascribed to the formation of stable crystalline Fe and Al oxides bound As and the reduction of labile As fractions in the soil. The labile As fractions were pH dependent and it followed a "V" shaped profile with the change of pH. In field experiment, the dose of CaO(2) application at 750 kg ha(-1) was optimal and at which the celery was found to produce the highest biomass (63.4 Mg ha(-1)) and lowest As concentration (0.43 mg kg(-1)). CaO(2) probably has a promising potential as soil amendment to treat As contaminated soils.

[Biological responses of maize seedlings to single and combined stress of cadmium and phenanthrene].

Maize (Zea mays L.) pot-culture experiments were conducted in this study for exploring the biological responses of maize seedlings to single and joint stress of Cadmium (Cd) and phenanthrene. The results showed that single-Cd treatment with Cd concentration ranging from 0 to 50 mg/kg had no significant influences on the above-ground biomass, root biomass, and the soluble protein of maize seedlings; with the increase of Cd concentrations, the maize leaf SOD activities appeared as an increasing-decreasing trend, while the POD, CAT, APX activities increased persistently. The APX is very sensitive to Cd stress, which increased 38% than control treatment at lower Cd treatment (1 mg/kg). The accumulation of O2-* is one of the main cause of single-Cd toxicity. Under the Cd-phenanthren combined stress, the SOD activity increased at lower Cd concentration (1 mg/kg) , which can reached to 1.66 times of control treatment, and decreased when Cd concentration becomes high. The SOD activity is a sensitive index in response to the Cd-phenanthren combined pollution. Unlike SOD activity, the activities of POD, CAT and APX were obviously induced by combined pollution of Cd and phenanthren; but these enzyme activities decreased when compared with the single-Cd stress, which suggested that the combined toxicity of Cd and phenanthrene is stronger than the single-Cd stress. And the accumulation of O2-* and *OH is one of the main cause of Cd-phenanthrene combined toxicity.

An investigation of cellular distribution of manganese in hyperaccumlator plant Phytolacca acinosa Roxb. using SRXRF analysis.

Phytolacca acinosa Roxb. (P. acinosa) is a recently discovered manganese hyperaccumulator plant from southern China. It is a good candidate for phytoremediation of manganese(Mn) polluted soil for its high biomass and fast growth. Knowledge of the tissue localization and identification of heavy metals can provide essential information on metal toxicity and bioaccumulation mechanisms. Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe was used in this study to investigate the cellular distributions of Mn and other elements in root, stem, leaf, petiole and midrib of P. acinosa. The highest Mn content was found in the vascular tissues of root, stem, petiole and midrib. Cortex in root played a key role in Mn absorption and Mn was limited in the vascular bundle during the process of transportation in stem. Moreover, Mn content in leaf epidermis was higher than that in mesophyll, which suggested that the sequestration of Mn in leaf epidermis might be one of the detoxification mechanisms of P. acinosa. The significance of other elemental (such as P, S, K, Ca, Fe, Zn and Cu) distribution patterns and the correlation with Mn were also discussed.