Enhanced degradation of organic contaminants using catalytic activity of carbonaceous structures: A strategy for the reuse of exhausted sorbents.

Generation of hydroxyl radicals (⋅OH) is the basis of advanced oxidation process (AOP). This study investigates the catalytic activity of microporous carbonaceous structure for in-situ generation of ⋅OH radicals. Biochar (BC) was selected as a representative of carbon materials with a graphitic structure. The work aims at assessing the impact of BC structure on the activation of H2O2, the reinforcement of the persistent free radicals (PFRs) in BC using heavy metal complexes, and the subsequent AOP. Accordingly, three different biochars (raw, chemically- and physiochemically-activated BCs) were used for adsorption of two metal ions (nickel and lead) and the degradation of phenol (100 mg/L) through AOP. The results demonstrated four outcomes: (1) The structure of carbon material, the identity and the quantity of the metal complexes in the structure play the key roles in the AOP process. (2) the quantity of PFRs on BC significantly increased (by 200%) with structural activation and metal loading. (3) Though the Pb-loaded BC contained a larger quantity of PFRs, Ni-loaded BC exhibited a higher catalytic activity. (4) The degradation efficiency values for phenol by modified biochar in the presence of H2O2 was 80.3%, while the removal efficiency was found to be 17% and 22% in the two control tests, with H2O2 (no BC) and with BC (no H2O2), respectively. Overall, the work proposes a new approach for dual applications of carbonaceous structures; adsorption of metal ions and treatment of organic contaminants through in-situ chemical oxidation (ISCO).

Urea functionalization of ultrasound-treated biochar: A feasible strategy for enhancing heavy metal adsorption capacity.

The main objective of a series of our researches is to develop a novel acoustic-based method for activation of biochar. This study investigates the capability of biochar in adsorbing Ni(II) as a hazardous contaminant and aims at enhancing its adsorption capacity by the addition of extra nitrogen and most probably phosphorous and oxygen containing sites using an ultrasono-chemical modification mechanism. To reach this objective, biochar physically modified by low-frequency ultrasound waves (USB) was chemically treated by phosphoric acid (H3PO4) and then functionalized by urea (CO(NH2)2). Cavitation induced by ultrasound waves exfoliates and breaks apart the regular shape of graphitic oxide layers of biochar, cleans smooth surfaces, and increases the porosity and permeability of biochar's carbonaceous structure. These phenomena synergistically combined with urea functionalization to attach the amine groups onto the biochar surface and remarkably increased the adsorption of Ni(II). It was found that the modified biochar could remove > 99% of 100 mg Ni(II)/L in only six hours, while the raw biochar removed only 73.5% of Ni(II) in twelve hours. It should be noted that physical treatment of biochar with ultrasound energy, which can be applied at room temperature for a very short duration, followed by chemical functionalization is an economical and efficient method of biochar modification compared with traditional methods, which are usually applied in a very severe temperature (>873 K) for a long duration. Such modified biochars can help protect human health from metal-ion corrosion of degrading piping in cities with aging infrastructure.

[Effects of Shenxiong pill on infarct brain volumes and NF-kappaB expression in SD rats with middle cerebral artery occlusion (MCAO)].

OBJECTIVE: To investigate the effects of Shenxiong Pill on the infarct volume and expression of NF-kappaB in brains of rats with middle cerebral artery occlusion. METHODS: 169 SD rats were randomly divided into five groups: normal group, sham group, model group, cyclophosphamide group and Shenxiong Pill group. MCAO rat models were established by string ligation (for model, cyclophosphamide-treated and Shenxiong-treated groups). Rats in the Shenxiong Pill group was further randomly divided into sub-groups, receiving a range of high dose treatment (5 to 20 times of clinical dosage). Brains of the rats were examined 48 h or 72 h after interventions in a random order. Image processing software was used in the calculation of volume of cerebral infarction. Conventional HE staining was used for observation of brain tissue. Immunohistochemical method was used to determine NF-kappaB expression. RESULTS: Compared with the model group, rats treated with Shenxiong Pill and cyclophosphamide had lower infarct brain volumes (P < 0.05). NF-kappaB positive inflammatory cells were not found in the normal and sham groups. But the MCAO model rats had increased numbers of NF-kappaB positive inflammatory cells and higher integral optical density of NF-kappaB over time. Compared with the model group, lower numbers and expression of NF-kappaB positive inflammatory cells were found in those treated with Shenxiong Pill (P<0. 05). Higher dosage of Shenxiong was associated with lower numbers and expression of NF-gB inflammatory cells (P<0. 05). CONCLUSION: Shenxiong Pill can reduce pathological damage to brains as a result of cerebral ischemia, possibly through inhibiting the expression and activation of NF-kappaB.

[Mild cognitive impairment disease treated with electroacupuncture: a multi-center randomized controlled trial].

OBJECTIVE: To verify the clinical efficacy on mild cognitive impairment (MCI) treated with electroacupuncture (EA) intervention based on the principle as "promoting the circulation of the Governor Vessel and regulating the marrow" and plan to provide the A-grade evidence of the evidence-based medicine for the clinical treatment of this disease with acupuncture and moxibustion. METHODS: The multi-center randomized controlled trial (RCT) was adopted. One hundred and ninety-two cases of MCI were randomized into an EA group and a nimodipine group, 96 cases in each one. In the EA group, EA was applied to Shenting (GV 24), Baihui (GV 20), Sishen cong (EX-HN 1) and Fengchi (GB 20), once every other day. In the nimodipine group, Nimodipine was pre scribed for oral administration. Four weeks constituted one course, the treatment of 8 weeks was required. The minimum mental state examination (MMSE) and the graphic recognition test (GRT) were applied before and in the 1st and 2nd session of treatment separately. The follow-up visit of MMSE scale was provided in the 1st, 3rd and 6th months after treatment separately. RESULTS: The total effective rate was 50.0% (47/94) in the EA group, which was superior to 34.4% (32/93) in the nimodipine group (P < 0.05). At the end of the 1st session treatment, the differences in MMSE total score and the cognitive, memory and speech dimensional scores were not significant statistically between two groups (all P > 0.05). At the end of the 2nd session treatment, the MMSE total score and the cognitive, memory, visual-space skill dimensional scores were improved in comparison before treatment (all P < 0.05). The results in the EA group were superior to those in the nimodipine group (all P < 0.05). But the difference in the speech dimensional score was not significant statistically between the two groups (P > 0.05). In the EA group, the GRT score was improved significantly after 2 sessions of treatment as compared with that before treatment (P < 0.01) and was superior to that in the nimodipine group (P < 0.05). In the 1st, 3rd and 6th month after treatment, the MMSE scale total scores were different significantly in statistics between the two groups (all P < 0.01). The long-term efficacy in the EA group was superior to that in the nimodipine group. CONCLUSION: Both of the EA therapy based on the principle as "promoting the circulation of the Governor Vessel and regulating the marrow" and the nimodipine program improve significantly the cognitive function of MCI patients. Compared with the nimodipine program, the EA therapy improves the comprehensive cognitive and the short-term memory abilities much more significantly and is especially advantageous at improving cognitive, memory and visual-space skill dimensions for MCI patients. In the half a year follow-up visit after the end of treatment, the long-term efficacy of EA is better than that of Nimodipine.

[Effect of tanshinone IIA pretreatment on IL-1ß and RelA mRNA expression in rats with focal cerebral ischemia].

OBJECTIVE: To observe the effect of tanshinone IIA (TS IIA) pretreatment on the expression of the inflammatory factor IL-1ß and RelA mRNA in rats with focal cerebral ischemia. METHODS: A total of 100 adult male SD rats were randomly divided into 6 groups, namely the model, ischemic preconditioning (IPC), TSIIA preconditioning, TSIIA treatment, sham-operated, and blank control groups. In the former 4 groups, rat models of focal cerebral ischemia were established with corresponding treatments. The expressions of IL-1ß and RelA mRNA in each group were detected using RT-PCR. RESULTS: All the groups showed expressions of IL-1ß and RelA mRNA with the exception of the blank control group. Compared to the model group, TSIIA preconditioning group, TSIIA treatment group, and IPC group all had significantly reduced expression of IL-1ß and RelA mRNA (P < 0.05). The expressions were lower in IPC group than in TSIIA preconditioning group and TSIIA treatment group(P < 0.05), and no significant difference was found in the expressions between the latter two groups. CONCLUSION: The protective effect of pretreatment with TS IIA against cerebral ischemia is related to the reduction of IL-1ß and RelA mRNA expressions.

Improvements on a gravity-driven low-rate particle feeder.

A gravity-driven particle feeder has been modified to achieve sustained operation at steady rates. Particle reservoirs and rod for controlling the nozzle opening are completely redesigned. Particle attrition and rod wobbling are the two main contributors to the feed instabilities. They, in turn, are affected by the height of the particle bed, particle contact time with the moving rod, strength of the magnetic field, and the weight, shape, and position of the rod in the magnetic field. A secondary reservoir minimizes the residence time of particles in the main reservoir. Its shape, orientation, and connection with the main reservoir have profound influences on the feeding stabilities. Tests have been conducted with particles of different types, sizes, and feed rates; results showed good long-term and short-term stabilities.

A gravity-driven low-rate particle feeder.

A gravity-driven particle feeder has been designed, fabricated, and tested to feed particles at low rates. A solenoid and a digital timer regulate the feed rate. This design avoids moving parts at the system periphery and thus avoids possible air leakages. It does not use pressurized gas to blow the particles into the desired location and thus pressure disturbance is avoided. The feeder can be operated at either a batch or a near continuous mode. Moreover, feeding a single large particle at a desired time is also feasible in such gaseous environments.

[Effect of the recombinant staphylokinase on pancreatic ischemia in severe acute pancreatitis of rats].

OBJECTIVE: To investigate the changes in plasma endothelin-1 (ET-1) , von Willebrand factor (vWF), serum 6-keto-prostaglandin(1alpha) (PGF(1alpha)) , thromboxane B2 (TXB2), platelet aggregation rate maximum (PAGm) and pancreatic blood flow after reproduction of severe acute pancreatitis (SAP) in rat, and the effect of recombinant staphylokinase (r-Sak) on SAP. METHODS: Eighty-one SD rats were divided randomly into the sham-operated group (n=27), the SAP model group (n=27), and the r-Sak treatment group (n=27). SAP was produced by administration of 5% sodium taurocholate into the pancreatic duct. The abdomen of rats was opened at 6, 12 and 18 hours after reproduction of SAP for determining the pancreatic blood flow. Blood was obtained at 6, 12 and 18 hours after reproduction of SAP for determining the concentration of plasma vWF with enzyme-labeled immunosorbent assay (ELISA). The concentration of plasma ET-1 and serum 6-keto-PGF(1alpha), and TXB2 were detected by radioimmunoassay. The PAGm induced by collagen and eicosanoids was assessed. RESULTS: Pancreatic blood flow in the SAP group appeared to have a decreasing trend at 6,12 and 18 hours after operation and were significantly decreased at all time points after reproduction of the model, compared with those of the sham-operated group (all P<0.05). The PAGm, content of plasma ET-1, vWF, and TXB2 were significantly increased at all time points after reproduction of the model, while 6-keto-PGF(1alpha) was significantly decreased, compared with those of the sham-operated group (all P < 0.05). Compared with SAP model group, PAGm, the content of plasma ET-1, vWF, and serum TXB2 in the r-Sak group were decreased at all time points, however, the content of serum 6-keto-PGF(1alpha) was increased (all P<0.05). CONCLUSION: The r-Sak can improve pancreatic microcirculation and enhance pancreatic blood flow in rats with SAP, and may be beneficial in the treatment of SAP.

Stochastic modeling of nonlinear epidemiology.

The objectives of this paper to analyse, model and simulate the spread of an infectious disease by resorting to modern stochastic algorithms. The approach renders it possible to circumvent the simplifying assumption of linearity imposed in the majority of the past works on stochastic analysis of epidemic processes. Infectious diseases are often transmitted through contacts of those infected with those susceptible; hence the processes are inherently nonlinear. According to the classical model of Kermack and McKendrick, or the SIR model, three classes of populations are involved in two types of processes: conversion of susceptibles (S) to infectives (I) and conversion of infectives to removed (R). The master equations of the SIR process have been formulated through the probabilistic population balance around a particular state by considering the mutually exclusive events. The efficacy of the present methodology is mainly attributable to its ability to derive the governing equations for the means, variances and covariance of the random variables by the method of system-size expansion of the nonlinear master equations. Solving these equations simultaneously along with rates associated influenza epidemic data yields information concerning not only the means of the three populations but also the minimal uncertainties of these populations inherent in the epidemic. The stochastic pathways of the three different classes of populations during an epidemic, i.e. their means and the fluctuations around these means, have also been numerically simulated independently by the algorithm derived from the master equations, as well as by an event-driven Monte Carlo algorithm. The master equation and Monte Carlo algorithms have given rise to the identical results.

Modeling growth of a heterogeneous tumor.

It has long been recognized that the growth of tumor population depends on the initial age distribution of the cells in the tumor and the age-dependent cellular birth rate. Deterministic dual-cell models have been available for sometime; these models take into account the effects of the resultant cell heterogeneity. Nevertheless, these models ignore various variables significantly affecting the growth, such as those characterizing the cells' inherent properties and environmental factors. Uncertainties, or fluctuations, arise when the growth is simulated with the models. Stochastic analysis of these fluctuations is the focus of the current work. Two types of cells are visualized to proliferate separately and to transform mutually during the process. The master equations of the system have been formulated through probabilistic population balance around a particular state by considering all mutually exclusive events. The governing equations for the means, variances, and covariance of the random variables have been derived through the system-size expansion of these nonlinear master equations. The stochastic pathways of the two different types of cells have been numerically simulated by the algorithm derived from the master equation for two different physical situations, one without and, the other, with the chemotherapeutic treatment. The results of the current study illuminate the significance of stochastically modeling the responses of the tumor to a variety of medicinal treatments: The coefficient of variation of the malignant cells' population magnifies with time under chemotherapeutic regimens. Consequently, the impact of the uncertainties in the exact number of malignant cells as expressed by this coefficient of variation is highly unpredictable. For example, it becomes increasingly uncertain if or how fast these cells will reactivate to become a full-blown carcinogenic tumor after treatment.