Pharmacokinetics of 4-Hydroxybenzaldehyde in Normal and Cerebral Ischemia-Reperfusion Injury Rats Based on Microdialysis Technique.

AIM: 4-Hydroxybenzaldehyde (4-HBd) is used for the treatment of headaches, dizziness, and convulsions. The objective of this study was to characterize the pharmacokinetics of 4-HBd in cerebral ischemia-reperfusion injury (CIRI) rats by microdialysis technology with high-performance liquid chromatography with diode-array detection (HPLC-DAD) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). METHODS: Microdialysis was used to collect blood, feces, and urine of normal and CIRI model rats. Pharmacokinetic parameters were determined using HPLC-DAD and 4-HBd metabolites were determined using UPLC-MS. RESULTS: After gavage of 4-HBd in normal and middle cerebral artery occlusion/reperfusion (MCAO/R) rats, it was widely distributed to all tissues (heart, liver, spleen, lung, kidney, and brain) in both the equilibrium and elimination phases, and the distribution pattern was basically the same; the highest concentration was found in the brain. The absolute bioavailability of 4-HBd was 5.33%; however, after intragastric administration in normal and MCAO/R rats, fecal and urinary excretion of 4-HBd accounted for 0.02% and 0.01% and for 0.01% and 0.03% of the dosage, respectively. Furthermore, 4-HBd was rapidly metabolized into 4-hydroxybenzoic acid (4-HBA) after administration in both the control and MCAO/R groups. Compared with the control, the peak time of 4-HBd plasma concentration in the MCAO/R rats decreased from 10.67 min to 8.83 min, the area under the concentration-time curve decreased significantly, and the half-life increased from 31.81 min to 78.85 min. CONCLUSIONS: The rapid absorption and low absolute bioavailability of 4-HBd by gavage in rats are followed by rapid and wide distribution to various tissues and organs, including the brain. The prototype drug is excreted in the feces and urine in low amounts, and it is metabolized to 4-HBA in large amounts in vivo; the pathological state of the MCAO/R model mainly affects its absorption degree and metabolism rate.

Evaluation of a biomarker (NO) dynamics in inflammatory zebrafish and periodontitis saliva samples via a fast-response and sensitive fluorescent probe.

Many pathological processes include nitric oxide (NO), a signaling transduction molecule. Tumors, cardiovascular, cerebrovascular, neurodegenerative, and other illnesses are linked to abnormal NO levels. Thus, evaluating NO levels in vitro and in vivo is crucial for studying chemical biology process of associated disorders. This work devised and manufactured a coumarin-based fluorescent probe ZPS-NO to detect nitric oxide (NO). The reaction between ZPS-NO and NO produced a highly selective and sensitive optical response that caused a powerful fluorescence "turn-on" effect with a ultra-low NO detection limit of 14.5 nM. Furthermore, the probe was applied to sense and image NO in living cells and inflammatory model of zebrafish, as well as to detect NO in periodontitis patients' saliva samples. We anticipate that probe ZPS-NO will serve as a practical and effective tool for assessing the interactions and evaluation of periodontitis development.

Bioprinted PDLSCs with high-concentration GelMA hydrogels exhibit enhanced osteogenic differentiation in vitro and promote bone regeneration in vivo.

OBJECTIVES: We aimed to explore the osteogenic potential of periodontal ligament stem cells (PDLSCs) in bioprinted methacrylate gelatine (GelMA) hydrogels in vitro and in vivo. MATERIALS AND METHODS: PDLSCs in GelMA hydrogels at various concentrations (3%, 5%, and 10%) were bioprinted. The mechanical properties (stiffness, nanostructure, swelling, and degradation properties) of bioprinted constructs and the biological properties (cell viability, proliferation, spreading, osteogenic differentiation, and cell survival in vivo) of PDLSCs in bioprinted constructs were evaluated. Then, the effect of bioprinted constructs on bone regeneration was investigated using a mouse cranial defect model. RESULTS: Ten percent GelMA printed constructs had a higher compression modulus, smaller porosity, lower swelling rate, and lower degradation rate than 3% GelMA. PDLSCs in bioprinted 10% GelMA bioprinted constructs showed lower cell viability, less cell spreading, upregulated osteogenic differentiation in vitro, and lower cell survival in vivo. Moreover, upregulated expression of ephrinB2 and EphB4 protein and their phosphorylated forms were found in PDLSCs in 10% GelMA bioprinted constructs, and inhibition of eprhinB2/EphB4 signalling reversed the enhanced osteogenic differentiation of PDLSCs in 10% GelMA. The in vivo experiment showed that 10% GelMA bioprinted constructs with PDLSCs contributed to more new bone formation than 10% GelMA constructs without PDLSCs and constructs with lower GelMA concentrations. CONCLUSIONS: Bioprinted PDLSCs with high-concentrated GelMA hydrogels exhibited enhanced osteogenic differentiation partially through upregulated ephrinB2/EphB4 signalling in vitro and promoted bone regeneration in vivo, which might be more appropriate for future bone regeneration applications. CLINICAL RELEVANCE: Bone defects are a common clinical oral problem. Our results provide a promising strategy for bone regeneration through bioprinting PDLSCs in GelMA hydrogels.

Targeting CD47 Inhibits Tumor Development and Increases Phagocytosis in Oral Squamous Cell Carcinoma.

BACKGROUND: Our previous work demonstrated upregulated CD47 in Oral Squamous Cell Carcinoma (OSCC). OBJECTIVE: In the present study, we aimed to investigate the effects of CD47 on tumor cell development and phagocytosis in OSCC and elucidate the underlying mechanisms. METHODS: The proliferation, apoptosis, migration, and invasion of oral cancer cells were analyzed after knocking down the expression of CD47. The effects of CD47 on tumor development were also evaluated using a murine model of OSCC. The involvement of CD47 in the phagocytosis of oral cancer cells was identified. RESULTS: Cell proliferation was suppressed by knocking down the expression of CD47 in human OSCC cell line Cal-27 cells but there was no change in the apoptosis rate. Moreover, impaired expression of CD47 inhibited the migration and invasion of Cal-27 cells. Furthermore, we found that nude mice injected with CD47 knockeddown Cal-27 cells displayed decreased tumor volumes at week 9 compared to xenograft transplantations of blank Cal-27 cells. In addition, in vitro phagocytosis of Cal-27 cells by macrophages was significantly enhanced after the knockdown of CD47, which positively correlated with compromised STAT3/JAK2 signaling. CONCLUSION: In summary, the knockdown of CD47 downregulated the development of OSCC and increased the phagocytosis of Cal-27 cells, indicating that CD47 might be a promising therapeutic target.

Stable Loading and Delivery of Icaritin Using PEG-PCL Micelles for Effective Treatment of Oral Squamous Cell Carcinoma.

BACKGROUND: Icaritin can inhibit cell proliferation and induce apoptosis in Oral Squamous Cell Carcinoma (OSCC). However, low solubility limits its clinical usage. OBJECTIVES: To improve the efficacy of icaritin treatment, a micelle system was designed for targeted delivery of drugs to OSCC cells. METHODS: In the present study, the micelles loaded with icaritin were self-assembled from the amphipathic polymer via film dispersion. Nanoparticles were characterized with the transmission electron microscope and dynamic light scattering. The cytotoxicity of icaritin nanoparticles was analyzed by CCK-8, and in vitro target-selective intracellular uptake behaviors were observed using a laser confocal microscope. RESULTS: The micelles were spherical with the mean diameter of 121.2 nm. in vitro studies revealed that icaritin was stablely and slowly released from micelles. Cytotoxicity analysis demonstrated that icartin-loaded micelles exhibited better therapeutic efficacy compared with free icaritin. Cellular uptake and intracellular release results revealed that micelles efficiently delivered icaritin into OSCC cells. CONCLUSION: These results suggest that encapsulated icaritin in polycaprolactone - polyethylene glycol (PCL-PEG) micelles may provide safe and effective drug delivery in OSCC treatments.

Reduced glutathione does not further reduce contrast-induced nephropathy in elderly patients with diabetes receiving percutaneous coronary intervention.

OBJECTIVE: To investigate the preventive effect of hydration combined with reduced glutathione on contrast-induced nephropathy (CIN) after coronary intervention therapy in elderly Chinese patients with diabetes. METHODS: Patients with diabetes aged ≥65 years, who received percutaneous coronary intervention (PCI) between 1 August 2016 and 31 December 2018, were enrolled and randomized into two groups: patients treated with hydration combined with reduced glutathione (treatment group) and patients who received hydration alone (controls). Serum creatinine and creatinine clearance levels were measured in all patients before PCI and then daily for 3 days after PCI. Occurrence of CIN (the primary endpoint) was defined as serum creatinine value 25% or 44.2 mmol/l (0.5 mg/dl) above baseline at 72 h after an exposure to contrast medium. RESULTS: A total of 396 patients were included (treatment group, n = 204; and controls, n = 192). The CIN occurrence rate in the treatment and control group was 5.88% and 6.77%, respectively, with no statistically significant between-group difference. CONCLUSION: In elderly patients with diabetes receiving PCI, the risk of CIN was not effectively lowered by hydration combined with reduced glutathione.

Acute myocardial infarction in pregnancy: spasm caused by hyperthyroidism?

We present a 26-year-old woman with ST-segment elevation myocardial infarction in the 14th week of pregnancy. Coronary angiography revealed no abnormalities in the coronary arteries. She had no history of coronary risk factors such as smoking, diabetes mellitus, hypertension, or dyslipidemia. Although we do not have direct evidence of coronary spasm in this patient, several factors suggest that coronary spasm is the most likely cause of myocardial infarction. We suspect that hyperthyroidism may have played an important role in coronary spasm in this patient. Early use of coronary angiography is helpful to identify the types of coronary artery lesions.

Osthole protects against Ang II-induced endotheliocyte death by targeting NF-κB pathway and Keap-1/Nrf2 pathway.

Osthole, the main active constituents in traditional Chinese medicine fructus cnidii, has anti-inflammatory and anti-oxidant activities. Apoptosis of vascular endothelial cells is an important cause of cardiovascular disease. Inflammation and oxidative stress are two key factors in injury of endotheliocyte. In this study, we investigated the effect of osthole on Ang II-induced apoptosis of rat aortic endothelial cells (RAECs) and explored the underlying mechanisms. In the present study, the protective effects of osthole on RAECs induced by Ang II in vitro were tested. Additionally, molecular docking and molecular dynamics (MD) simulations were utilized to investigate the potential binding mode of osthole to NF-κB and Keap1. Our results showed osthole remarkably attenuates Ang II-induced apoptosis of RAECs via alleviating inflammation and oxidative stress. Molecular docking and MD simulations revealed the potential interaction of osthole bind to the P65 subunit of NF-κB and the Keap1 protein, an adaptor for the degradation of Nrf2. We further found that osthole decreased Ang II-induced inflammation and oxidative stress through respectively modulating NF-κB and Nrf2 pathways in RAECs. These studies provide evidence that osthole may represent a potential therapeutic agent for the treatment of vascular injury.

Co-Delivery of Rose Bengal and Doxorubicin Nanoparticles for Combination Photodynamic and Chemo-Therapy.

Carboxymethyl chitosan (CMCS) is applied as a nanodelivery system carrier for sustained intracellular release of rose bengal (RB) and doxorubicin (DOX) to achieve combinational drug treatments. An integral analytical method was used to characterize the structure of CMCS-RB, the amount of RB and DOX, the average particle size, the zeta potential, and the morphology, including Fourier transform infrared (FTIR), nuclear magnetic resonance (1H NMR), ultraviolet visible spectroscopy (UV-Vis), scanning electron microscope (SEM), laser particle size analyzer and transmission electron microscopy (TEM). The results revealed that the maximum encapsulation efficiency and loading capacity of DOX into the CMCS-RB-DOX nanoparticles was 13.38% and 53.18%, respectively. The content of RB in the CMCS-RB prodrug was 11.25%. The release of RB and DOX under different conditions was investigated through dynamic dialysis. CCK-8 assay were used to study the inhibitory effect on normal cells and Cal-27 oral cancer cells. The cytotoxicity results of CMCS-RB-DOX nanoparticles showed excellent photosensitizer properties and strong efficacy of photodynamic therapy (PDT).

Electrochemical mechanism of tin membrane electrodeposition under ultrasonic waves.

Tin was electrodeposited from chloride solutions using a membrane cell under ultrasonic waves. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CHR), and chronopotentiometry were applied to investigate the electrochemical mechanism of tin electrodeposition under ultrasonic field. Chronoamperometry curves showed that the initial process of tin electrodeposition followed the diffusion controlled three-dimensional nucleation and grain growth mechanism. The analysis of the cyclic voltammetry and linear sweep voltammetry diagrams showed that the application of ultrasound can change the tin membrane electro-deposition reaction from diffusion to electrochemical control, and the optimum parameters for tin electrodeposition were H+ concentration 3.5 mol·L-1, temperature 35 °C and ultrasonic power 100 W. The coupling ultrasonic field played a role in refining the grain in this process. The growth of tin crystals showed no orientation preferential, and the tin deposition showed a tendency to form a regular network structure after ultrasonic coupling. While in the absence of ultrasonic coupling, the growth of tin crystals has a high preferential orientation, and the tin deposition showed a tendency to form tin whiskers. Ultrasonic coupling was more favorable for obtaining a more compact and smoother cathode tin layer.

Ischemic stroke in patients with POEMS syndrome: a case report and comprehensive analysis of literature.

BACKGROUND: POEMS syndrome is a rare multi-systemic disease characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes. Arterial or venous thrombosis is a less-common complication of POEMS syndrome. Ischemic stroke has also been reported sporadically. However, the association between POEMS syndrome and ischemic stroke has not been entirely understood. METHODS: A case of ischemic stroke caused by cerebral vasculitis in a patient with POEMS syndrome was presented. Then a comprehensive review and analysis of the literature were performed. RESULTS: A total of 28 patients were identified. The common clinical manifestations of POEMS syndrome were rather non-specific in patients with ischemic stroke compared with those of patients without ischemic stroke. Twenty patients were found with multiple ischemic lesions (71.5%). In the 25 patients who had undergone the evaluation of cerebral arteries, nineteen patients (76.0%) were found with cerebral vasculopathy. Twelve patients (48.0%) had more than one cerebral artery involved. Ischemic events were documented in 8 patients even when they were undergoing all the therapy for ischemic stroke. Ten (55.6%) of the 18 patients who had survival data died within two years after stroke events. CONCLUSION: Comprehensive analysis of literature revealed several trends in patients with ischemic stroke and POEMS syndrome including a low survival rate and a preponderance of cerebral vasculopathy and multiple cerebral arteries affected. Ischemic stroke may be a poor outcome predictor in patients with POEMS syndrome. Further researches focusing on a larger cohort may help in better characterizing and treating this rare complication of POEMS syndrome.

Perimesencephalic nonaneurysmal subarachnoid hemorrhage caused by transverse sinus thrombosis: A case report and review of literature.

RATIONALE: Perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSAH) is characterized by a pattern of extravasated blood restricted to the perimesencephalic cisterns, normal angiographic findings, and an excellent prognosis with an uneventful course and low risks of complication. The precise etiology of bleeding in patients with PNSAH has not yet been established. The most common hypothesis is that PNSAH is venous in origin. Intracranial venous hypertension has been considered as the pivotal factor in the pathogenesis of PNSAH. The underlying venous pathology such as straight sinus stenosis, jugular vein occlusion may contribute to PNSAH. We describe a patient in whom transverse sinus thrombosis preceded intracranial venous hypertension and PNSAH. These findings supported that the source of the subarachnoid hemorrhage is venous in origin. PATIENT CONCERNS AND DIAGNOSES: A 45-year-old right-handed man was admitted to the hospital with a sudden onset of severe headache associated with nausea, vomiting, and mild photophobia for 6 hours. The patient was fully conscious and totally alert. An emergency brain computed tomography (CT) revealed an acute subarachnoid hemorrhage restricted to the perimesencephalic cisterns. CT angiography revealed no evidence of an intracranial aneurysm or underlying vascular malformation. Digital subtraction angiography of arterial and capillary phases confirmed the CT angiographic findings. Assessment of the venous phase demonstrated right transverse sinus thrombosis. Magnetic resonance imaging confirmed the diagnosis of cerebral venous sinus thrombosis (CVST). Lumbar puncture revealed an opening pressure of 360 mmH2O, suggestive of intracranial venous hypertension. Grave disease was diagnosed by endocrinological investigation. INTERVENTIONS: Low-molecular-weight heparin, followed by oral warfarin, was initiated immediately as the treatment for cerebral venous sinus thrombosis and PNSAH. OUTCOMES: The patient discharged without any neurologic defect after 3 weeks of hospital stay. MR venography revealed recanalization of right transverse sinus at the 6-month follow-up. No clinical or neuroimaging evidence of relapse was detected at 12 months follow-up. LESSONS: Hyperthyroidism may contribute to the development of CVST. The presence of acute transverse sinus thrombosis, as a cause of PNSAH, provides further support for the hypothesis that the source of PNSAH is venous in origin and intracranial venous hypertension plays a critical role in the pathogenesis of PNSAH.

Icaritin Reduces Oral Squamous Cell Carcinoma Progression via the Inhibition of STAT3 Signaling.

Icaritin, a traditional Chinese medicine, possesses antitumor activity. The current study aimed to investigate icaritin effect and potential mechanism on oral squamous cell carcinoma (OSCC) development. OSCC cells proliferation, apoptosis, and autophagy were analyzed after incubation with icaritin at different concentrations and incubation times. The expressions of proteins related to proliferation, apoptosis, and autophagy, as well as signal transducer and activator of transcription 3 (STAT3) signal network, were also evaluated by western blot. Furthermore, STAT3 was knocked down by siRNA transfection to determine STAT3 role in OSCC cell proliferation and apoptosis. An oral specific carcinogenesis mouse model was used to explore icaritin effect on OSCC in vivo. Icaritin significantly inhibited OSCC proliferation in vitro and reduced the expression of both the cell-cycle progression proteins cyclin A2 and cyclin D1. Besides, icaritin increased cleaved caspase 3 and cleaved poly-(ADP-ribose) polymerase expression leading to apoptosis, and it activated autophagy. Icaritin significantly inhibited the expression of phospho-STAT3 (p-STAT3) in a dose- and time-dependent manner. In the in vivo experiment, the number of malignant tumors in the icaritin-treated group was significantly lower than the control. Overall, icaritin suppressed proliferation, promoted apoptosis and autophagy, and inhibited STAT3 signaling in OSCC in vitro and in vivo. In conclusion, icaritin might be a potential therapeutic agent against OSCC development.

Different Expression of MicroRNA-146a in Peripheral Blood CD4(+) T Cells and Lesions of Oral Lichen Planus.

Oral lichen planus (OLP) is a common T cell-mediated chronic inflammatory disease of unknown etiology. Recent increasing evidence indicates that microRNA-146a (miR-146a) plays a vital role in inflammatory diseases and T cell regulation. This study aimed to investigate the expression of miRNA-146a in peripheral blood CD4(+) T cells and local OLP lesions and to evaluate its relationship with clinical forms of OLP. Sixteen patients with OLP were divided into two groups: erosive OLP and nonerosive OLP. The expression of miR-146a was examined by quantitative real-time polymerase chain reaction. The expression of miR-146a in peripheral blood CD4(+) T cells showed no significant difference between OLP group and control group (P > 0.05), and among erosive OLP, nonerosive OLP, and control groups (P > 0.05 for all). The expression in local lesions of the OLP group was significantly higher than that of the control group (P = 0.003), and it was significantly higher in the erosive OLP group than in the non-erosive OLP (P = 0.010) and control groups (P = 0.007). However, miR-146a expression in the nonerosive OLP group did not significantly differ from that in the control group (P > 0.05). These data indicate that miR-146a might be more involved in the local immune disorder of OLP. MiR-146a might be utilized as a candidate biomarker to estimate the severity of OLP.

Expression of T-bet and GATA-3 in peripheral blood mononuclear cells of patients with oral lichen planus.

OBJECTIVE: Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory oral disease of unknown aetiology. Imbalanced cytokine production by Th1 and Th2 probably contributes to the pathogenesis of OLP. Growing evidence has suggested that two Th1/Th2-specific transcription factors, T-bet and GATA-3, may play a critical role in the development of Th1 and Th2 immunity. The aim of the present study was to investigate the mRNA expressions of T-bet and GATA-3 in the peripheral blood mononuclear cells of OLP subjects, and their expression patterns in relation to several clinical features. DESIGN: Expressions of T-bet and GATA-3 mRNA in peripheral blood mononuclear cells isolated from twenty-eight OLP subjects and sixteen controls were detected by real-time reverse transcription-polymerase chain reaction. RESULTS: When OLP subjects were regarded as a whole group, T-bet mRNA level and the ratio of T-bet/GATA-3 mRNA in OLP subjects were significantly higher (P<0.05) than those in controls. When the OLP subjects were divided according to different clinical forms, genders or age groups, T-bet, but not GATA-3, mRNA levels in reticular (P<0.01), female (P<0.05) and elder (age>55, P<0.05) OLP patients were significantly higher than those in control subjects. T-bet/GATA-3 mRNA ratio only in reticular (P<0.05) OLP subjects was significantly higher than that in control subjects. CONCLUSIONS: The results implicate a predominant role of Th1-type immune response in pathogenesis of OLP. Different gene expressions of T-bet in different clinical features may indicate different immunoregulatory mechanisms of OLP.

Heavy metal removal and crude bio-oil upgrading from Sedum plumbizincicola harvest using hydrothermal upgrading process.

The main aim of this study was to separate heavy metals and yield crude bio-oil from a heavy metals hyperaccumulator harvest, Sedum plumbizincicola, through hydrothermal upgrading process. Parameters such as granularity, temperature, pressure, and duration were examined for their effect on the removal efficiency of heavy metals and upgrading efficacy of crude bio-oil. Maximum heavy metal removal efficiency of >99% and crude bio-oil upgrading efficiency of >63% were attained with an 18 mesh (1mm) granularity, and 22.1MPa at 370 degrees C in the presence of 10mg/L additives for 60s. Under these optimized conditions, an oil phase (mostly composed of phenolic hydrocarbons and derivatives), a water phase raffinate containing Zn(2+) (0.39g/L), Pb(2+) (0.10g/L), Cu(2+) (0.16g/L), and a solid phase (the hydrothermal upgrading residue, which completely satisfies the limit set by China legislation related to biosolids disposal, were obtained).

Heavy metal removal and crude bio-oil upgrading from Sedum plumbizincicola harvest using hydrothermal upgrading process.

The main aim of this study was to separate heavy metals and yield crude bio-oil from a heavy metals hyperaccumulator harvest, Sedum plumbizincicola, through hydrothermal upgrading process. Parameters such as granularity, temperature, pressure, and duration were examined for their effect on the removal efficiency of heavy metals and upgrading efficacy of crude bio-oil. Maximum heavy metal removal efficiency of >99% and crude bio-oil upgrading efficiency of >63% were attained with an 18 mesh (1 mm) granularity, and 22.1 MPa at 370 degrees C in the presence of 10 mg/L additives for 60 s. Under these optimized conditions, an oil phase (mostly composed of phenolic hydrocarbons and derivatives), a water phase raffinate containing Zn2+ (0.39 g/L), Pb2+ (0.10 g/L), Cu2+ (0.16 g/L), and a solid phase (the hydrothermal upgrading residue, which completely satisfies the limit set by China legislation related to biosolids disposal, were obtained).

Heavy metal removal and crude bio-oil upgrade from Sedum alfredii Hance harvest using hydrothermal upgrading.

In this study, heavy metals were removed and crude bio-oil was yielded from a heavy metal hyperaccumulator harvest, Sedum alfredii Hance, through hydrothermal upgrading process. This paper reports on the optimization of process parameters for the removal of heavy metals (zinc, lead, and copper) and for the upgrading of crude bio-oil from this biomass in an autoclave. Parameters such as granularity, temperature, pressure, and duration were examined for their effect on the removal efficiency of heavy metals and upgrading efficacy of crude bio-oil. Maximum heavy metal removal efficiency of >99% and crude bio-oil upgrading efficiency of >60% were attained with an 18 mesh (1 mm) granularity, and 22.1 MPa at 370 degrees C in the presence of 10 mg/L additives (K(2)CO(3)) for 60 s. Under these optimized conditions, an oil phase (mostly composed of phenolic hydrocarbons and derivatives), a water phase raffinate (containing Zn(2+) (0.39 g/L), Pb(2+) (0.10 g/L), Cu(2+) (0.15 g/L)), and a solid phase (the hydrothermal upgrading residue, which completely satisfies the limit set by China legislation related to biosolids disposal) were obtained.

Recovery of zinc from hyperaccumulator plants: Sedum plumbizincicola.

Hyperaccumulator biomass harvested after heavy-metal phytoremediation must be considered as hazardous waste that should be contained or treated appropriately before disposal or reuse. As a potential method to detoxify the biomass and to convert this material to a suitable fertilizer or mulch, leaching of heavy metals from Sedum plumbizincicola biomass was studied by using ammonia-ammonium chloride solution as a leaching agent. The research was carried out in two phases: (i) a leaching study to determine the heavy metal:zinc extraction efficiency of this leaching agent and (ii) a thermodynamic analysis to identify the likely reactions and stable Zn(II) species formed in the leaching systems. Experimentally, a Taguchi orthogonal experiment with four variable parameter elements: leaching temperature, nNH4Cl:nNH3 ratio, leaching time and solid-liquid ratio, each at three levels, was used to optimize the experimental parameters by the analysis of variances. Application of the Taguchi technique significantly reduced the time and cost required for the experimental investigation. The findings indicate that leaching temperature had the most dominant effect on metal extraction performance, followed by nNH4Cl:nNH3 ratio, solid-liquid ratio and leaching time. Accordingly, the optimum leaching conditions were determined as temperature: 60 degrees C, nNH4Cl:nNH3 = 0.6, leaching time: 2 h and solid/liquid ratio: 5:1. The total zinc removal after leaching under the optimum conditions reached 97.95%. The thermodynamic study indicated that the dominant species produced by the leaching process should be the soluble species Zn(NH3)4(2+).