Physiochemical response of Cicer arietinum to zinc-containing mesoporous silica nanoparticles under water stress

Chickpea is an important food legume cultivated in semiarid regions, where water scarcity and nutrient deficiencies negatively affect crop production. This study aimed to investigate the effect of zinc and silicon from different sources, including bulk and nanostructures, on various biochemical traits of chickpea plants grown under field conditions in Maragheh, Northwest Iran. The main experimental factor consisted of three soil moisture levels: irrigation to 90% of field capacity (FC), 60% FC, and 30% FC. The subplots were assigned for foliar application of different fertilizers: control (distilled water), zinc sulfate (ZnSO), silicon dioxide nanoparticles (SiO2 NPs), ZnSO + SiO2 NPs, and zinc-containing mesoporous silica nanoparticles (MSNPs -Zn). The results showed that although decreased soil moisture had a negative impact on several biochemical processes, foliar application of Zn and Si in both conventional bulk and nanostructure significantly affected plant antioxidant system, plasma membrane integrity, and the concentrations of photosynthetic pigments and compatible solutes. However, the most inducing effects on catalase, ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase, and anthocyanin were observed with the foliar spray of MSNPs-Zn and ZnSO + SiO2 under 60% FC. Moreover, foliar spray of MSNPs-Zn alleviated the negative effects of water deficit stress on photosynthetic pigments (chlorophyll a /b and carotenoid content). Water stress significantly induced the accumulation of free proline in the leaves. Overall, the results indicated that foliar spray of MSNPs -Zn, especially under 60% FC, improved the plant's defense system, scavenged reactive oxygen species, and enhanced the accumulation and stability of pigments, thereby mitigating the effects of drought stress.

Lead-Free Piezoelectric (Ba,Ca)(Zr,Ti)O3 Thin Films for Biocompatible and Flexible Devices

In this work, we report the synthesis of functional biocompatible piezoelectric (1 - x)Ba(Ti_0.8Zr_0.2)TiO₃-x(Ba_0.7Ca_0.3)TiO₃, x = 0.45 (BCZT45), thin films with high piezoelectric properties. Pulsed-laser-based techniques, classical pulsed-laser deposition and matrix-assisted pulsed-laser evaporation, were used to synthesize the BCZT45 thin films. The second technique was employed in order to ensure growth on polymer flexible Kapton substrates. The BCZT45 thin films grown by both techniques show similar structural properties and high piezoelectric coefficient coupling between the mechanical loading and electrical potential. While it has long been shown that the electrical potential favors biological processes like osteogenesis, the assessment of cell adhesion and osteogenic differentiation onto BCZT materials has not yet been demonstrated. We prove here for the first time that BCZT 45 coatings on Kapton polymer substrates provide optimal support for osteogenic differentiation of mesenchymal stem cells in the bone marrow.

Effect of nano-silicon foliar application on safflower growth under organic and inorganic fertilizer regimes

Silicon nanoparticles have distinctive physicochemical characteristics and are able to enter into plants and impact the metabolism of plants as well as improve plant growth and yield under unfavourable environmental conditions. Besides, low soil organic matter content, imbalanced nutrient and inadequate water supply may adversely affect crop productivity in semiarid areas. To understand the effects of foliar spray of silicon dioxide nanoparticles (nSiO2) with application of farmyard manure (FYM) or inorganic fertilizer on morpho-physiological traits and yield of safflower, a field experiment was carried out in a highland semiarid region of Maragheh, northwest Iran. The experiment consisted of two levels of nSiO2 (0 and 20 mM) and four fertilizer regimes (control, 15 t ha−1 FYM, 30 t ha−1 FYM, 90 kg ha−1 N-P-K chemical fertilizer). Safflower plants were treated with nSiO2 suspension at leaf development, branching and capitulum emergence stages. Although the nSiO2 significantly improved some growth parameters such as canopy spread, stem diameter, plant height, ground cover and the number of achenes in capitulum, it did not affect achene yield and harvest index. However, fertilizer treatments considerably affected most of morpho-physiological traits, achene yield and yield components. The result showed that the best growth and the highest achene yield were achieved by application of 30 t ha−1 FYM before sowing. Application of high FYM increased the achene yield by 48% compared to the control, however, application of N-P-K chemical fertilizer or of 15 t ha−1 FYM improved achene yield only up to 17% over the no fertilizer condition. Moreover, this work revealed some positive effects of exogenous application of nSiO2 on safflower growth. This finding suggests that application of organic fertilizers with foliar spray of nSiO2 can improve safflower production and is an advisable agronomic option.

Limitations when use chloramphenicol-bcyclodextrins complexes in ophtalmic solutions buffered with boric acid/borax system

Chloramphenicol eye drops are commonly prescribed in concentrations of 0.5-1% in the treatment of infectious conjunctivitis. In terms of ophthalmic solution preparation, the major disadvantage of chloramphenicol consists in its low solubility in water. The solubility is increased by substances that form chloramphenicol-complexes, for example: boric acid/borax or cyclodextrins. Objective: Experimental studies aimed to evaluate the potential advantages of enhancing the solubility and stability of chloramphenicol (API) by molecular encapsulation in b-cyclodextrin (CD), in formulation of ophthalmic solutions buffered with boric acid/borax system. Methods and Results: We prepared four APIb- CD complexes, using two methods (kneading and co-precipitation) and two molar ratio of API/b-cyclodextrin (1:1 and 1:2). The formation of complexes was proved by differential scanning calorimetry (DSC) and the in vitro dissolution tests. Using these compounds, we prepared eight ophthalmic solutions, formulated in two variants of chloramphenicol concentrations (0.4% and 0.5%). Each solution was analyzed, by the official methods, at preparation and periodically during three months of storing in different temperature conditions (4°C, 20°C and 30°C). Conclusions: Inclusion of chloramphenicol in b-cyclodextrin only partially solves the difficulties due to the low solubility of chloramphenicol. The protection of chloramphenicol molecules is not completely ensured when the ophthalmic solutions are buffered with the boric acid/borax system.

Development of a modified-release pellets formulation--with metoprolol tartrat and kinetic aspects of in vitro release

AIM

The development of a new pellets formulation which is able to modulate the release of metoprolol tartrate, an active pharmaceutical ingredient very soluble in water and therefore very difficult to process.

MATERIALS AND METHODS

Two types of different viscosity grade hydroxypropyl methylcellulose (Methocel K100; HPMC 15.000) and Eudragit NE30D are used as prolonged drug release agents, thus resulting in three formulations which have been prepared in form of pellets, in a conventional coating pan. The obtained pellets are characterized and compared in terms of: particles size distribution, drug loading efficiency, drug content and kinetic of in vitro drug release.

RESULTS

Lower amounts of Eudragit NE30D (7.5%) determine more uniform size distributions of particles. Drug content and charging efficiency is higher in case of fractions ranging in size from 0.80 to 1.25 mm. The combination of HPMC 15000 with 10% Eudragit NE30D leads to a prolongation for a period of 11.5 hours of metoprolol tartrate release. Release kinetics analysis was performed by fitting the in vitro release profile with different kinetic models.

CONCLUSIONS

It was developed a pellets formulation that release in vitro the metoprolol tartrate in an extended mode, with Korsmeyer-Peppas kinetic-type.

Thymectomy by thoracoscopic approach in myasthenia gravis

BACKGROUND

A series of 25 thoracoscopic thymectomies performed in the Department of General Surgery and Liver Transplantation of the Fundeni Clinical Institute between April 1999 and April 2000 is analyzed.

METHODS

Thoroscopic thymectomies were performed on 4 male patients (16%) and 21 female patients (84%), aged between 8 and 60 years.

RESULTS

The mean operative time was 90 (+/-15) min. There were no conversions to open thymectomy. Mortality was nil, and morbidity consisted of one minor postoperative right pneumothorax probably related to a injury to right mediastinal pleura that was not observed intraoperatively. Hospital stay ranged from 2 to 4 days, with a mean of 2.28 days. The patients were transferred to the neurological department and they were usually discharged after 1 more day.

CONCLUSIONS

Postoperatively, all patients had clinical improvement of their disease both in symptoms and medication requirements, but a longer follow-up is necessary. The results are edifying regarding the very low morbidity, the lack of mortality, the acceptance of the patients, and the short hospitalization.

[Video-assisted thoracoscopic thymectomy--preliminary results]

Video-assisted thoracoscopic surgery (VATS) provides a new approach to thymectomy. From April 1999 to December 1999, we performed a total of 10 video-assisted thoracoscopic thymectomies for myasthenia gravis (MG). There were one male and nine female patients with ages ranging from 8 to 59 years. Thymoma was present in one of the ten patients. We considered that complete thymectomy was accomplished in all cases by examination of the thymic bed and of the resected specimen. There was no mortality or intraoperative complications. The median postoperative hospital stay was 4 days. Clinical improvement was observed in all patients after this short follow-up. Compared with a similar historical group of patients with MG who underwent transsternal thymectomy, the VATS group was associated with significantly less analgesic requirement and shortened hospital stay. We conclude that VAT thymectomy is technically feasible and is associated with a favorable postoperative course compared with the transsternal approach. We believe that complete thymectomy can be achieved by this approach. Further investigation with long-term follow-up is needed to further clarify the role of VAT thymectomy in thoracic surgery.

The antagonism between pineal peptides and catecholamines. I. The action of the pineal peptide extract on some effects of exogenous adrenaline in the rat

The effects of adrenaline alone or associated with Crinofizin, a pineal polypeptide extract, were studied on rats. The drug given 15 minutes before a hyperglycemic adrenaline dose counteracted the pharmacologic effects with lethal consequences of catecholamine as well as certain metabolic effects such as elevation of blood levels of glycerol, phospholipids and cholesterol. Post-adrenaline hyperglycemia was not reduced by Crinofizin under the given experimental circumstances. The glycogenolytic effect of adrenaline was slightly inhibited.

RNA biosynthesis in lymphocytes from various chronic diseases (cytochemical, cytoautoradiographic, optic and electronic study)

In lymphocytes of patients with myasthenia gravis and systemic lupus erythematosus high indices of uridin labelling were very often encountered, similar to those observed in evident malignant diseases such as chronic lymphocytic leukemia and Hodgkin's disease. The electron cytoautoradiographic investigations showed particularly that large sized nucleoli and even the giant ones are sometimes not the result of an RNA-hypersynthesis but of an RNA accumulation. The utility of such data for the therapy with immunodepressing drugs is discussed.

Significance of T and B lymphocytes in different chronic internal diseases with immune processes

The T and B lymphocytes were determined by the rosette test in the peripheral blood of 100 patients with internal chronic diseases with immune processes such as: chronic hepatitis, systemic lupus erythematosus, myasthenia gravis, chronic lymphocytic leukemia and lymphosarcoma. The values obtained were compared with those in 10 controls. The mean per cent values of the T lymphocytes in the controls were 33 (29-38%) and of the B lymphocytes 25.2 (16-43%). In the patients investigated the values varied, namely: in chronic hepatitis and systemic lupus erythematosus the T lymphocytes were generally low while the B lymphocytes were moderately high. In myasthenia gravis both T and B lymphocytes were below the control values. In chronic lymphocytic leukemias and lymphosarcomas the per cent values of the T lymphocytes were generally low while those of the B lymphocytes were high. The significance of these results for the immunologic implications of the lymphocyte populations is discussed and an attempt is made to correlate these data with the nucleologram variations.