117 research outputs found
Clinical outcome of combined scaphocapitate fusion and posterior interosseous neurectomy for stage III Kienbock’s disease
Background: Treatment of Kienbock’s disease is still controversial. Several authors have described various surgical treatment options for Kienbock’s disease, all of whom reported successful treatment outcomes. The purpose of this study is to explore the clinical results of posterior interosseous neurectomy and scaphocapitate fusion as a treatment option for stage III Kienbock’s disease.Methods: This study evaluated the range of motion, grip and functional results after treatment of ten wrists of stage III Kienbock’s disease. Four males and six females with average age of 26.3 years, seven dominant and three non-dominant wrists were included. Two patients were smokers while six were housewives, three manual workers and a lawyer. The average follow up period was 14.2 months.Results: Four patients revealed excellent, three good and three fair results. The mean modified Mayo score was 81.5. Flexion-extension range was 105.5° representing 74.9% of the contralateral side range. The mean flexion and extension range of operated side was increased, while the flexion increase was nonsignificant. Regarding radial-ulnar deviation, the mean range was 33.5° representing 76.5% of the contralateral side. The mean ulnar and radial deviation was increased, while the radial increase was nonsignificant. The mean grip strength was significantly increased to 90 mmHg representing 93.2% of the contralateral side.Conclusions: Scaphocpitate fusion is a recommended solution for treatment of late stages of Kienbock’s disease with lunate collapse. Longer postoperative time has a positive impact on grip strength and flexion-extension range of motion
Kinetic Simulation of He radio frequency capacitive coupled plasma
Radiofrequency capacitively coupled plasma is studied theoretically using a
Particle-in-Cell code. For He discharge, the time-averaged sheaths are in the
range of few centimeters. The sheath potential, ion, and electron energy and
angular distributions, discharge current, and dissipated power depend on the
driven potentials and frequencies. Increasing the amplitude of the high radio
frequencies increases the bulk density and the sheath potential and,
consequently, increases the plasma processing rate. Increasing the intermediate
radio frequency amplitude allows a wider sheath with a broad ion energy
distribution and a narrower ion angular distribution. Changing the amplitude
and the phase shift between driven frequencies provide different energies and
angular distribution allowing performing various processes. The interplay
between the sheath and bulk dynamics in the intermediate radiofrequency regime
and the high-frequency regime may excite harmonics in the discharge current
Preparation and characterization of water-absorbing composite membrane for medical applications
The present work introduces a novel method for the formation of water absorbing composite membrane. The prepared composite is based on chitosan, carboxymethyl cellulose (CMC), and Montmorillonite. Prepared composite membrane exhibits high water absorbing and holding capacity with increasing clay content. The water absorbency was studied as a function of the hydrogel composition and the medium pH. Structure and morphologies of the prepared composite have been characterized by X-ray diffraction (XRD), and transmission electron microscope (TEM). TEM study showed that the formed membrane is homogenous and prepared uniformly.Keywords: Composite, clay, superabsorber, chitosan, carboxymethyl cellulose, composite membrane
Comparative studies on the efficacy of lincomycin and bacitracin for the control of necrotic enteritis in broiler chickens
Background: The present study was conducted to evaluate the efficacy of lincomycin and/or bacitracin for control of experimentally-induced Clostridium perfringens (CP) infection in broiler chickens.Methods: A total of 100 one-day-old Cobb-mixed chicks were divided into five groups (A, B, C, D and E, each of 20 bird). At the 15th day of age, all birds (except group A) were inoculated orally with CP broth culture (109 CFU/mL). Two days later, drugs were orally administered once daily for five consecutive days as follow; Group A and B were left untreated. Group C, D, and E were treated with lincomycin (0.5 g/l), bacitracin (100 mg/l), lincomycin and bacitracin, respectively. The efficacy of used drugs was estimated based on clinical symptoms, body weight, weight gain, feed conversion rate. Hematobiochemical changes were also determined.Results: Necrotic enteritis in broiler chickens induced a significant decrease in body weight, weight gain, erythrocytic count, hemoglobin content, PCV %, serum proteins, catalase, and superoxide dismutase. Additionally, a marked decrease in serum lipids was obtained. Furthermore, a significant increase in feed conversion rate, leukocytic count, phagocytic activity, phagocytic index, serum total globulin, γ globulin and malondialdehyde coupled with a marked increase in β and α globulins were determined. Medication of infected broilers with lincomycin and/or bacitracin improved clinical signs and reduced mortality rate to 8, 6 and 2%, respectively, as well as restored the performance and hematobiochemical alterations.Conclusions: a combination of lincomycin and bacitracin was of considerable value for the control of necrotic enteritis in broiler chickens
Evaluation of upper 1st molar rotation during maxillary canine retraction in 1st premolar extraction cases at 6 weeks reactivation interval. A clinical trial.
Abstract:
Purpose: the aim of this clinical trial is to investigate maxillary first molar rotation during maxillary canine retraction at 6 weeks re-activation intervals with elastic power chain in first premolar extraction cases. Material and methods: a total of 20 quadrants of 10 orthodontic patients requiring maxillary canine retraction after extraction of upper 1st premolars were recruited. Mini-screws (TADs) were used directly for maximum anchorage. Canines were retracted on 0.016×0.022-inch stainless steel arch wire using elastic power chain extending from a power arm on canine bracket to the miniscrew. Cone beam computed tomography (CBCT) was used to measure the upper first molar rotation. Results: The mean difference of the first molar rotation between pre-retraction and post-retraction measurements was 0.6250o ± 0.6o which was statistically insignificant. Conclusion: There is no significant difference between pre-retraction and post-retraction upper first molar rotation re-activated every 6 weeks using power chain
A comparative study of the effects of different low-level lasers on the proliferation, viability, and migration of human melanocytes in vitro.
The aim of this study was to investigate the effects of different low-level laser therapies (LLLTs) of various wavelengths and energies on normal cultured human melanocytes. Various studies have shown the effects of LLLs on various types of cultured cells. Presently, little is known about the biological effects of LLLTs on melanocytes. Melanocytes were exposed to LLLT at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 J/cm(2) using a blue (457 nm), red (635 nm), or ultraviolet (UV) (355 nm) laser. Melanocyte viability, proliferation, and migration were monitored at 72 h after irradiation. The blue (P < 0.001) and red (P < 0.001 and P < 0.01) lasers significantly enhanced viability at 0.5 to 2.0 J/cm(2), whereas the UV laser (P < 0.001) could significantly enhance viability only at 0.5 and 1.0 J/cm(2) compared with controls. The blue and red lasers also significantly enhanced the proliferation of the melanocytes at 0.5 to 2.0 J/cm(2) (P < 0.001), and the UV laser significantly enhanced proliferation at 0.5 to 1.5 J/cm(2) (P < 0.001 and P < 0.01) compared with controls. The blue laser significantly enhanced melanocyte migration at 0.5 to 4.0 J/cm(2) (P < 0.001 to P < 0.05), but the red (P < 0.001 and P < 0.01) and UV (P < 0.001 to P < 0.05) lasers could significantly enhance such migration at 0.5 to 1.0 J/cm(2) and 0.5 to 2.0 J/cm(2), respectively, compared with controls. LLLT at low energy densities is able to significantly increase melanocyte viability, proliferation, and migration in vitro, and at higher energy densities, it gives non-stimulatory results. Additionally, the blue laser was the best among the three lasers. These findings might have potential application in vitiligo treatment in future
Physical pegylation enhances the cytotoxicity of 5-fluorouracil-loaded PLGA And PCL nanoparticles.
Purpose :
The main goal of this study is to evaluate the impact of physical incorporation of polyethylene glycol (PEG) into 5-fluorouracil (5-FU)-loaded polymeric nanoparticles (NPs).
METHODS:
The 5-FU-loaded NPs were prepared utilizing a simple double emulsion method using polycaprolactone (PCL) and polylactic-co-glycolic acid (PLGA) with or without PEG 6000. The surface charge, particle size, and shape of NPs were evaluated by standard procedures. Both Fourier Transform Infrared Spectroscopy and X-ray diffraction spectra of the 5-FU loaded NPs were compared against the pure 5-FU. The in vitro release profile of 5-FU from the NPs was monitored by the dialysis tubing method. Cell death and apoptosis induction in response to 5-FU NP exposure were measured by MTT and Annexin-V/7-amino-actinomycin D (7-AAD) assays, respectively, in Daoy, HepG2, and HT-29 cancer cell lines.
RESULTS:
The 5-FU loaded NPs were found to be spherical in shape with size ranging between 176±6.7 and 253.9±8.6 nm. The zeta potential varied between -7.13± 0.13 and -27.06±3.18 mV, and the entrapment efficiency was between 31.96% and 74.09%. The in vitro release of the drug followed a two-phase mode characterized by rapid release in the first 8 hrs followed by a period of slow release up to 72 hrs with composition-based variable extents. Cells exposed to NPs demonstrated a significant cell death which correlated with the ratio of PEG in the formulations in Daoy and HepG2 cells but not in HT-29 cells. Formulations (F1-F3) significantly induced early apoptosis in HT-29 cell lines.
CONCLUSION:
The physical PEGylation significantly enhanced the entrapment and loading efficiencies of 5-FU into NPs formulated with PLGA and PCL. It also fostered the in vitro cytotoxicity of 5-FU-loaded NPs in both Daoy and HepG2 cells. Induction of early apoptosis was confirmed for some of the formulations
Influence of blend ratio on the electrical characteristics of vulcanized SBR/NBR blends compatibilized by Cis-polybutadiene rubber
Blends composed of styrene butadiene rubber (SBR) and acrylonitrile-butadiene rubber (NBR) have been fabricated by melt-blending technique using two-roll mill blend machine. Cis-polybutadiene rubber (CBR) was used as a compatibilizer for enhancing the homogeneity between blend phases. No previous reports were found to discuss improving electrical properties of vulcanized SBR/NBR blends using unfilled rubber system (i.e. no fillers incorporation). SEM micrographs were utilized to verify the compatibility between two rubber ingredients in various blends, owing to the use of compatibilizer. Thermal stability of blends was investigated by differential thermal analysis (DTA) and differential scanning calorimetric (DSC) to evaluate the influence of blend ratio on the compatibility of investigated samples. Results revealed that the dielectric properties of blends are dramatically influenced by altering the blend ratio. The results revealed that the SEM observations confirmed the compatibilization effect of CBR on vulcanized SBR/NBR blends. Meanwhile, thermal properties of vulcanized SBR/NBR blends were enhanced with increasing of SBR contents in blends. The complex impedance graphs showed circular arcs showing the bulk contribution to overall electrical behavior for investigated vulcanized SBR/NBR blends. During I-V characteristics have been presented, where a remarkably change from linear behavior to nonlinear conduction at lower temperatures was found for 0SBR/100NBR blends. These findings supported and confirmed that the compatibilization effect and the blend ratio between rubber compositions have strongly influenced on their thermal and electrical properties of vulcanized blends
Ligating Behavior Of Some Sulphur Containing Benzotriazole Derivatives Towards Some Transition Metal Ions And Their Biological Effect
Abstract: New Cu 2+ and Ni 2+ complexes of N 1 -phenyl-2-[1H-1,2,3-bezotriazol-1-yl] 3-phenyl-3-oxopropane thioamide, HL, has been synthesized and characterized by different spectral and magnetic measurements and elemental analysis. The spectral studies indicated that HL exist in the thion form in the solid state and the IR spectra of the complexes indicated that the ligand act as monobasic bidentate ligand giving distorted tetragonal structure in case of Cu 2+ and square planar structure in case of Ni 2+ , which was the reason of their different antimicrobial activity. Thermal decomposition of both complexes showed similar steps
Influence of photoinitiator concentration and irradiation time on the crosslinking performance of visible-light activated pullulan-HEMA hydrogels
In-situ forming hydrogels were prepared from pullulan-HEMA copolymer using three-component visible-light system composed of camphorquinone carboxylic acid-folic acid-iodonium salt. The relevance of double bond conversion and crosslinking density of hydrogels with the photoinitiator concentration and irradiation time were estimated by FT-IR analysis and swelling calculation using Flory-Rehner theory, respectively. The results revealed that the crosslinking density and degree of conversion of hydrogels were improved by photoinitiator concentration increasing until certain extend, then they decreased due to a primary radicals termination reaction occurred. The shortest irradiation time of 10 s was essential to obtain acceptable hydrogels for further characterizations. For the probability use of hydrogels as scaffold was investigated in vitro by measuring of the indirect cytotoxicity assay by MTT-assay using human bone Sarcoma cell as a reference cell lines. The majority of seeded SW1353 cells maintained a live with an accepted viability of ~85–92% over a four days culture period with irradiation of hydrogel 10 s, while cell viability has improved to ~95–98% with prolonging the irradiation time of hydrogel to 60 s. The current photoinitiating system is a proper system for in-situ crosslinking the activated-light biomaterials for bone regeneration, dental, or tissue engineering applications
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