Experience with continuous venovenous hemodiafiltration in four newborns: A case series and review of the literature

When conventional methods for treating complicated problems such as acute and chronic renal failure or metabolic diseases fail, the therapy of choice is peritoneal dialysis (PD) in neonatal period. However, in cases that involve technical difficulties, such as bulky lesions in the abdomen or complications from previous abdominal surgeries, it is not always possible to place a peritoneal catheter. In such situations, continuous venovenous hemodiafiltration (CVVHDF) can be effective. This case series presents our experience in 2013 with the administration of CVVHDF to four patients in our neonatal intensive care unit who could not undergo PD for various reasons.     

Severe carbamazepine intoxication unresponsive to albumin‐enhanced continuous venovenous hemodiafiltration with low dialysate flow

Carbamazepine (CBZ) intoxication can be associated with severe toxicity, including neurological and cardio‐respiratory abnormalities. Highly protein‐bound, CBZ is not removed efficiently through conventional hemodialysis. Charcoal hemoperfusion is the most effective extracorporeal elimination therapy for CBZ intoxication. Recent reports have indicated that continuous venovenous hemodiafiltration (CVVHDF), albumin‐enhanced continuous venovenous hemodialysis, high‐flux hemodialysis and plasma exchange can be as effective as charcoal hemoperfusion. In contrast to recent reports, which demonstrated the effectiveness of CVVHDF with high dialysate flow in CBZ intoxication, we observed that serum CBZ level was decreased minimally by albumin‐enhanced CVVHDF with low dialysate flow. Therefore, albumin‐enhanced CVVHDF with high dialysate flow should be considered in severe CBZ intoxication, if hemoperfusion is unavailable because of the lack of facilities or if it cannot be performed.     

Cystatin C in critically ill patients treated with continuous venovenous hemofiltration

Assessment of residual renal function in critically ill patients with acute renal failure (ARF) treated with continuous venovenous hemofiltration (CVVH) is difficult. Cystatin C (CysC) is a low-molecular-weight protein (13.3 kDa) removed from the body by glomerular filtration. Its serum concentration has been advocated for assessment of renal function in patients with kidney disease. To investigate whether the removal of CysC by CVVH is likely to influence its serum concentration, concentrations of CysC were measured in 3 consecutive samples in 18 patients with oliguric ARF treated with CVVH (2 L/hr). Samples were taken from the afferent and efferent blood lines and from the ultrafiltrate line. Concentrations of CysC did not change during the time interval studied. The mean serum concentrations of CysC were 2.25+/-0.45 mg/L in the afferent and 2.19+/-0.56 mg/L in the efferent samples (NS); ultrafiltrate concentrations of CysC were 1.01+/-0.45 mg/L. The sieving coefficient of CysC was 0.52+/-0.20; the clearance of CysC was 17.3+/-6.6 mL/min; and the quantity of CysC removed averaged 2.13 mg/hr. During CVVH (2 L/hr), the quantity of CysC removed is less than 30% of its production and no rapid changes in its serum concentration are observed. Therefore, CVVH (2 L/hr) is unlikely to influence serum concentrations of CysC significantly, which suggests that it can be used to monitor residual renal function during CVVH.     

Carbamazepine and the active epoxide metabolite are effectively cleared by hemodialysis followed by continuous venovenous hemodialysis in an acute overdose

Hemodialysis (HD) and continuous venovenous hemodialysis (CVVHD) have an unproven role in the management of carbamazepine overdose. Albumin-enhanced CVVHD may accelerate carbamazepine (CBZ) clearance, but no pharmacokinetic data has been reported for traditional CVVHD without albumin enhancement. In addition, it is unclear whether the active CBZ-epoxide metabolite is removed with either mode of dialysis. We present a case of CBZ intoxication successfully managed with sequential HD and CVVHD. The CBZ half-life during CVVHD was 14.7 hours, compared with the patient's endogenous half-life of 30.8 hours. The CBZ-epoxide half-life was 3.2 hours during HD. We conclude that HD and CVVHD provide effective clearance of CBZ and the epoxide metabolite and should be considered in the management of an acute toxic ingestion.     

Quantitative analysis of convective dose in hemofiltration and hemodiafiltration: "predilution" vs. "postdilution" reinfusion

In hemofiltration (HF) and hemodiafiltration (HDF), removal of medium and high-molecular-weight solutes is greatly enhanced by convective mechanisms as compared with simple diffusion; increasing convective flows may allow greater removal rates of these solutes. Use of "predilution" (pre-H[D]F) may allow higher ultrafiltration rates than the "postdilution" mode (post-H[D]F); yet, the dilution of plasma water may have unpredictable effects on "endogenous" water convection. We have applied a mathematical analysis to evaluate and compare endogenous water convective flow rates in pre-H(D)F vs. post-H(D)F. Endogenous plasma water recovered in ultrafiltrate was calculated according to patient (hematocrit, total protein level) and session parameters (blood flow, ultrafiltration rate, programmed weight loss), in absolute terms and as a fraction of endogenous plasma water delivery to the filter. Maximally efficient post-H(D)F was modelled according to a preset postfilter hematocrit or filtration fraction. Nomograms were constructed expressing endogenous water convective fluxes in relation to parameters of interest (ultrafiltration rate, blood flow, hematocrit) with both post-H(D)F and pre-H(D)F, and "efficiency" of pre-H(D)F vs. post-H(D)F (as the ratio of endogenous water convective flow rate with the 2 techniques) as a function of the ultrafiltration/reinfusion rate. In post-H(D)F, the model predicts maximal ultrafiltration rates within the limits of a preset hemoconcentration at the filter outlet; additionally, the model allows to calculate ultrafiltration/reinfusion quantities to be set in pre-H(D)F to equal and overcome maximal convective efficiency of post-H(D)F. This "equivalence" ultrafiltration rate may greatly vary according to patient's hematocrit and blood flow, so that the ultrafiltrate-reinfusate volume available in the system dictates, in any patient, which mode of reinfusion may attain higher "endogenous" convective flow rates. Pre-H(D)F may allow higher fractional and absolute "endogenous" convective flow rates as compared with post-H(D)F, provided that adequate amounts of reinfusate are available. For lower reinfusate volumes than "equivalence" values, post-H(D)F remains a better option.     

Space–time computation techniques with continuous representation in time (ST-C)

We introduce space–time computation techniques with continuous representation in time (ST-C), using temporal NURBS basis functions. This gives us a temporally smooth, NURBS-based solution, which is desirable in some cases, and a more efficient way of dealing with the computed data. We propose two versions of ST-C. In the first version, the smooth solution is extracted by projection from a solution computed with a different temporal representation, typically a discontinuous one. We use a successive projection technique with a small number of temporal NURBS basis functions at each projection, and therefore the extraction can take place as the solution with discontinuous temporal representation is being computed, without storing a large amount of time-history data. This version is not limited to solutions computed with ST techniques. In the second version, the solution with continuous temporal representation is computed directly by using a small number of temporal NURBS basis functions in the variational formulation associated with each time step.     

Long-term continuous readout of a photorefractive memory with BaTiO(3) postamplification

We propose and demonstrate a long-term readout photorefractive memory. It is made up of two photorefractive crystals: the first where the images are stored and the second where the signal is amplified by use of a low-noise self-bent pump-beam technique, making it possible to use very low illumination of the storage crystal. A LiNbO(3)/BaTiO(3) configuration is used with angular multiplexing; this technique permits continuous readout for more than 60 days. The long-term storage capacity and the maximum number of stored images are estimated.     

Evaluation of reproductive toxicity in male rats treated with novel synthesized ruthenium(II) and gold(I)-NHC complexes

In this study, we aimed to determine the reproductive toxicity in rat induced by ruthenium(II)-NHC (Ru^II) and gold(I)-NHC (Au^I) complexes that have anticarcinogenic effects. For this purpose, 35 Sprague–Dawley rats were randomly divided into 5 equal groups. In control group, rats treated with saline, Ru^II, and Au^I complexes were intraperitoneally given high (10?mg/kg) and low (5?mg/kg) doses to rats via a one-time administration. The animals were sacrificed, and testis tissues were taken on Day 10 of the drug administration for the determination of the biochemical, histopathological, spermatological, and hormonal parameters. It was determined that treatment group that was subjected to treatment using both Ru^II and Au^I complexes significantly caused oxidative, histopathological, spermatological, and hormonal damage compared to control group. However, the sexual and accessory organ weight did not significantly change when compared to control. In addition, it was shown that Au^I treatment generally caused more adverse effects than Ru^II treatment in a dose-dependent manner. In conclusion, when these synthesized compounds are used for the treatment of cancer, they could cause toxic effects on male reproductive system and lead to infertility. However, Ru^II complex is a more preferable option in cancer treatment, particularly in terms of user safety.     

Evaluation of reproductive toxicity in male rats treated with novel synthesized ruthenium(II) and gold(I)-NHC complexes

In this study, we aimed to determine the reproductive toxicity in rat induced by ruthenium(II)-NHC (Ru(II)) and gold(I)-NHC (Au(I)) complexes that have anticarcinogenic effects. For this purpose, 35 Sprague-Dawley rats were randomly divided into 5 equal groups. In control group, rats treated with saline, Ru(II), and Au(I) complexes were intraperitoneally given high (10?mg/kg) and low (5?mg/kg) doses to rats via a one-time administration. The animals were sacrificed, and testis tissues were taken on Day 10 of the drug administration for the determination of the biochemical, histopathological, spermatological, and hormonal parameters. It was determined that treatment group that was subjected to treatment using both Ru(II) and Au(I) complexes significantly caused oxidative, histopathological, spermatological, and hormonal damage compared to control group. However, the sexual and accessory organ weight did not significantly change when compared to control. In addition, it was shown that Au(I) treatment generally caused more adverse effects than Ru(II) treatment in a dose-dependent manner. In conclusion, when these synthesized compounds are used for the treatment of cancer, they could cause toxic effects on male reproductive system and lead to infertility. However, Ru(II) complex is a more preferable option in cancer treatment, particularly in terms of user safety.     

ESR examination of thermally treated Fe (III) coprecipitated with Al(OH)3·nH2O

Journal of Materials Science Letters -     

Regeneration of hexamminecobalt(II) catalyzed by activated carbon treated with KOH solutions

The combined elimination of NO and SO(2) can be realized by hexamminecobalt(II) solution which is formed by adding soluble cobalt(II) salt into the aqueous ammonia solution. Activated carbon is used as a catalyst to regenerate hexamminecobalt(II), Co(NH(3))(6)(2+), so that NO removal efficiency can be maintained at a high level for a long time. In this study, KOH solution has been explored to modify coconut activated carbon to meliorate its catalytic performance in the reduction of hexamminecobalt(III), Co(NH(3))(6)(3+). The experiments have been performed in a batch stirred cell to investigate the effects of KOH concentration, impregnation duration, activation temperature and activation duration on the performance of activated carbon. The results show that the best KOH concentration for the improvement of activated carbon is 0.5 mol l(-1). The optimal impregnation duration is 9h. High temperature is favorable to ameliorating the catalytic performance of activated carbon. The optimum activation duration is 4h.     

多壁碳纳米管的处理及其在芳纶1313中的分散

为了改善多壁碳纳米管(MWNTS)在溶剂N,N-二甲基乙酰胺(DMAc)中的分散性,提高MWNTs与芳纶1313(PMIA)基体界面的结合性能,用混酸对MWNTs进行了处理,用FT-IR对处理前后的MWNTs进行了表征,发现处理后的MWNTs表面接上了羧基.通过溶液共混的方法制得了PMIA/MWNTs纳米复合薄膜,并用SEM和TEM对其进行了表征,发现处理后的MWNTs在PMIA基体中的分散更为均匀.     

The large-scale synthesis and characterization of carbon nanotubes filled with long continuous inorganic nanowires in supercritical CS(2)

Large-scale long continuous FeS(2) nanowire filled carbon nanotubes (CNTs) were one-step synthesized in the presence of NaN(3) in supercritical CS(2) at 500?°C using ferrocene as the iron source. The CNTs have outer diameters in the range of 15-25?nm and the core FeS(2) nanowires inside CNTs are characterized as single crystals, with an average diameter of 8?nm and up to several micrometres in length. The band gap of FeS(2) nanowire filled CNTs was determined as 5.69?eV from the ultraviolet and visible light absorption spectrum, showing its promise for application in reversible conversion between solar energy and electrical or chemical energy.     

Feasibility analysis of As(III) removal in a continuous flow fixed bed system by modified calcined bauxite (MCB)

This study examine the feasibility of As(III) removal from aqueous environment by an adsorbent, modified calcined bauxite (MCB) in a continuous flow fixed bed system. MCB exhibited excellent adsorption capacity of 520.2 mg/L (0.39 mg/g) with an adsorption rate constant 0.7658 L/mgh for an influent As(III) concentration of 1mg/L. In a 2 cm diameter continuous flow fixed MCB bed, a depth of only 1.765 cm was found necessary to produce effluent As(III) concentration of 0.01 mg/L, from an influent of 1 mg/L at a flow rate of 8 mL/min. Also, bed heights of 10, 20, and 30 cm could treat 427.85, 473.88 and 489.17 bed volumes of water, respectively, to breakthrough. A reduction in adsorption capacity of MCB was observed with increase in flow rates. The theoretical service times evaluated from bed depth service time (BDST) approach for different flow rates and influent As(III) concentrations had shown good correlation with the corresponding experimental values. The theoretical breakthrough curve developed from constantly mixed batch reactor (CMBR) isotherm data also correlated well with experimental breakthrough curve.