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991.
In this work, the adsorption of Cr(VI) ions and the organic dye Alizarin Red S (ARS) was investigated using magnetite talc (Fe3O4@Talc) nanocomposite. Different characterization techniques such as scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), and thermogravimetric analysis (TGA) were used to demonstrate the physical and chemical properties of the fabricated Fe3O4@Talc nanocomposite. In addition, the adsorption isothermic, kinetic, and thermodynamic properties were illustrated. The results demonstrate that the investigated adsorption processes obeyed the Langmuir isotherm model for Cr(VI) and the Freundlich isotherm model for ARS dye, with a maximum adsorption capacity of 13.5 and 11.76 mg·g−1, respectively, controlled by pseudo second-order kinetics. Regeneration and reusability studies demonstrated that the prepared Fe3O4@Talc nanocomposite is a promising and stable adsorbent with considerable reusability potential.  相似文献   
992.
Dental implant screw fracture involves attempting to retrieve the screw fragment or, as an alternative, attempting to salvage the dental implant. Circumstances that do not allow for screw retrieval require a solution in which the internal configuration of the dental implant can provide for a custom direct dowel fabrication. The proposed technique is to retrofit the fabrication of a custom cast dowel-core and provisional use of a direct procedure, which provides accuracy of fit, retention, and ease of production.  相似文献   
993.
The histopathologic changes of the peritoneum of the hemidiaphragm were studied in 30 patients with schistosomal liver disease and compared with ten control subjects. The diaphragmatic peritoneum of patients with ascites was markedly thickened with infiltration of inflammatory cells and collagen bundles resembling the interstitial changes of peripheral lymphedema. Obliteration of diaphragmatic lymphatic stomata with restricted lymph flow as well as excess lymph formation from portal hypertension are both major factors in the magnitude and intractability of ascites associated with schistosomal hepatic fibrosis.  相似文献   
994.
Cyclosporin-A (CsA) inhibits the in vitro bone-resorbing effects of cytokines. We investigated the in vivo effects of CsA on rat bone mineral metabolism. Three groups of male Sprague-Dawley rats were administered vehicle or low dose (7.5 mg/kg) or high dose (15 mg/kg) CsA for 14 and 28 days. Ionized calcium, PTH, serum bone Gla protein, blood urea nitrogen, creatinine, magnesium, and 1,25-dihydroxyvitamin D were determined serially. No significant changes in calciotropic hormones or renal function were noted. Significant bone resorption and trabecular bone loss occurred in the high dose group by day 14 and in both groups by day 28. Bone Gla protein was significantly increased within 2 weeks in both dosage groups (P less than 0.005), reflecting increased bone remodeling. CsA in vivo resulted in an unexpected and significant increase in bone remodeling, with striking bone loss. These effects are dependent on the duration and dose of CsA and appear to be mediated at a local level.  相似文献   
995.

Introduction

We compared the effects of 6 different rotary systems on transportation, canal curvature, centering ratio, surface area, and volumetric changes of curved mesial root canals of mandibular molar via cone-beam computed tomographic (CBCT) imaging.

Methods

Mesiobuccal root canals of 120 mandibular first molars with an angle of curvature ranging from 20°–40° were divided into 6 groups of 20 canals. Based on CBCT images taken before instrumentation, the groups were balanced with respect to the angle and radius of canal curvature. Root canals were shaped with the following systems with an apical size of 25: OneShape (OS) (MicroMega, Besancon, France), ProTaper Universal (PU) F2 (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next X2 (Dentsply Maillefer), Reciproc (R) R25 (VDW, Munich, Germany), Twisted File Adaptive (TFA) SM2 (SybronEndo, Orange, CA), and WaveOne primary (Dentsply Tulsa Dental Specialties, Tulsa, OK). After root canal preparation, changes were assessed with CBCT imaging. The significance level was set at P = .05.

Results

The R system removed a significantly higher amount of dentin than the OS, PU, and TFA systems (P < .05). There was no significant difference among the 6 groups in transportation, canal curvature, changes of surface area, and centering ratio after instrumentation.

Conclusions

The 6 different file systems straightened root canal curvature similarly and produced similar canal transportation in the preparation of mesial canals of mandibular molars. R instrumentation exhibited superior performance compared with the OS, TFA, and PU systems with respect to volumetric change.  相似文献   
996.
We performed this systematic review and meta-analysis to evaluate the tolerability and efficacy of intranasal sumatriptan, a selective serotonin agonist, compared to placebo or other migraine therapeutics for the treatment of acute migraine attacks. We searched PubMed, SCOPUS, Embase, and Cochrane CENTRAL for relevant randomized controlled trials (RCTs). Data were extracted from eligible studies and pooled as risk ratios (RR), using RevMan software. We performed subgroup and meta-regression analyses for different doses and treatment endpoints. Sixteen RCTs (n = 5925 patients) matched our inclusion criteria. The overall effect-estimate showed that intranasal sumatriptan was superior to placebo in terms of pain relief (RR = 1.70, 95% CI [1.31, 2.21], p < 0.0001) and headache relief (RR = 1.58, 95% CI [1.35, 1.84], p < 0.00001) at 2 h. Although sumatriptan was superior to placebo in terms of headache relief at 30 min (RR = 1.31, 95% CI [1.08, 1.59], p = 0.005), no significant difference was found between both groups in terms of the frequency of pain-free participants at 30 min (RR = 1.18, 95% CI [0.49, 2.88], p = 0.71). Subgroup analysis and meta-regression models showed that increasing the dose of sumatriptan reduced the time needed for headache relief; however, this clinical improvement with higher doses was associated with more frequent adverse events in comparison to smaller doses. In conclusion, intranasal sumatriptan is effective for the treatment of acute migraine attacks. However, it was associated with a six-fold increase in the risk of taste disturbance, compared to the placebo. Future RCTs are recommended to provide head-to-head comparison of different administration routes and drug formulations of sumatriptan.  相似文献   
997.
Valproic acid (VPA) is a widely used and well-tolerable antiepileptic drug in epileptic patients. However, VPA has many side effects dose-dependent or non-dose-dependent. It is reported that VPA treatment may lead to biotin deficiency and low serum and liver tissue biotinidase enzyme activity (BEA). Major clinical manifestations in biotin deficiency are seborrheic dermatitis, dry skin, fine and brittle hair, and alopecia. We aimed to investigate the effects of biotin supplementation on serum and liver tissue BEA and alopecia during VPA therapy. Rats were randomly divided into 4 groups, each consisted of 15 rats (VPA-B1, VPA-B2, VPA, and control). Except the control group, all groups were administrated VPA dose of 600 mg/kg/d per oral (PO) for 60 days with 12h intervals two divided doses. VPA-B1 was administrated biotin dose of 6 mg/kg/d and VPA-B2 was administrated biotin dose of 0.6 mg/kg/d. In the third week of the study, we determined alopecia in the study groups. Alopecia was seen in the subjects of 13.3% of VPA-B1 (n=2), 13.3% of VPA-B2 (n=2), and 40% of VPA (n=6). But statistical significant effect on alopecia by biotin supplementation was not able to be determined between the study groups. In the control group, alopecia was not observed. The ratios of alopecia in the study groups were statistically higher than the control group (p=0.028). Itchiness was more obvious in the study groups compared with the control group. Serum biotin levels of the biotin supplemented groups (VPA-B1 and VPA-B2) were higher than the other groups (VPA and control group). Serum biotin levels of the VPA group were lower than the control group. There were significant decreases in the levels of serum and liver tissue BEA of the study groups compared with the control group. In conclusion we showed that VPA usage reduced the serum and liver tissue BEA and impaired the biotin utilization by affecting the liver. Partial biotinidase deficiency may lead to alopecia. It might be prevented by biotin supplementation in the patients receiving VPA therapy. We considered that further studies are necessary to find out the effective and safe biotin dose.  相似文献   
998.
Introduction: In this study we investigated the effect of crush and axotomy of phrenic nerves on oxidative stress and antioxidant enzyme activities in rat diaphragm muscle. Methods: The animals in the first group were not crushed or axotomized and served as controls. Phrenic nerves of the rats in the second and third groups were crushed or axotomized in the diaphragm muscle. Results: The malondialdehyde level increased in diaphragm muscles after both crush and axotomy. The antioxidant enzymes, such as superoxide dismutase, glutathione peroxidase, carbonic anhydrase, and catalase, decreased in diaphragm muscles after both crush and axotomy. Conclusions: Crushing or axotomizing the phrenic nerves may produce oxidative stress in the diaphragm muscle of the rat by increasing lipid peroxidation and decreasing antioxidant enzyme activities. Muscle Nerve, 2012  相似文献   
999.
1000.
Studies have shown the use of non-steroidal anti-inflammatory drugs, such as ibuprofen could reduce the risk of Alzheimer’s disease. The drug-repurposing strategy offers a bright opportunity for these patients. Intranasal administration through the olfactory pathway provides noninvasive and direct drug delivery to the target brain. A novel ibuprofen microemulsion was prepared, characterized and assessed the brain uptake in rats. The solubility of ibuprofen in various oils, surfactants, co-surfactants, and different ratios of surfactant/co-surfactant mixtures was screened and the phase diagrams were constructed. The colloidal particle size was 166.3 ± 2.55 nm and the zeta potential was −22.7 mV. Conductivity and dilution test identified an O/W type microemulsion with pH 4.09 ± 0.08. The rheological study showed a Newtonian flow behavior with cP 10.633 ± 0.603 (mPa⋅s). A steady drug release and linear permeation profiles were observed and showed a 90% permeation rate from the released drug. Ibuprofen microemulsion showed excellent stability in 3-months accelerated storage conditions, heating-cooling and freeze-thaw cycles, accelerated centrifugation, and 6- and 12-months long-term storage conditions. In vivo studies in rats further demonstrated a 4-fold higher brain uptake of ibuprofen from the microemulsion compared to the reference solution and nearly 4-fold and 10-fold higher compared to the intravenous and oral administrations. This study provides an exciting repurposing strategy and new administration route for the treatment of Alzheimer’s disease.  相似文献   
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