a. hassanzadeh

Layered double hydroxides (LDH) have gained considerable attention for their potential application in agriculture, serving as a slow release sources of essential nutrients for plants. The appraising of LDH as a favorable fertilizer is in the early development, and more studies on the nutrient release mechanism of LDH are needed to answer the question of how LDH could replace commercial fertilizers for providing the stable nutrients for plants. Although several studies on the release of P from LDH exist in the literature, no information regarding ratios of divalent cation (M2+) to trivalent cation (M3+) in LDHs on phosphate release from LDHs is available. So, it is important to raise our knowledge about various parameters like pH and time on the solubility of LDHs. This study aimed to investigate the effects of pH and the ratios of M2+/M3+on the kinetics release of P from Mg-Al-LDH.

All the chemicals in this research, such as magnesium nitrate hexahydrate (Mg (NO3)2.6H2O) and aluminum nitrate nonahydrate Al(NO3)3.9H2O were of analytical grade and obtained from Merk (USA). The solutions were made with decarbonated pure water without impurities (electrical resistivity = 18 MΩcm). Two nitrate forms of Mg-Al-LDH were synthesized using the co-precipitation method at constant pH by varying the Mg/Al ratios (2:1 and 3:1) in the precursor solution. Briefly, 50 mL of 1M solution containing nitrate salt of divalent cations (Mg(NO3)2.6H2O) and trivalent cations (Al(NO3)3.9H2O) in the appropriate ratios (2:1 and 3:1) were added simultaneously for 2h to 400 mL of 0.01M solution of sodium hydroxide while being stirred vigorously in a nitrogen atmosphere. The pH was kept at 9.5 by adding volumes of 3 M NaOH. Afterward, the material was ripened in the synthesis mixture for 2 h and centrifuged at 3000 rpm for 20 min. The precipitates were washed by three washing-centrifugation cycles with Milli-Q water and subsequently dried at 70 °C. In this study, LDH-P was made by ion exchange. The LDH-N were treated with 0.05 M KH2PO4 solutions at pH 7.2. The suspensions were shaken end-over-end for 24h, followed by centrifugation, washing, and drying as described above. After digesting the dried LDHs in aqua regia (3:1 HCl/HNO3), the total P concentration of the LDHs was determined. The chemical composition of the synthesized LDHs was determined by graphite furnace atomic absorption spectrophotometry (SavantAA, GBC) after acid digestion (3:1 HCl/HNO3). Crystallization and morphology of the LDHs were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD patterns were prepared using an x-ray diffractometer (Panalytical x Pert Pro, Netherlands), at scan step time of 1s from 2θ=5° to 2θ=70° (40KV and 30 mA), and with a step size of 0.0260, which were used to identify the mineral phases. The phase purity was surveyed by comparing these XRD diagrams with those found in the literature. The SEM photographs were gained on a scanning electron microscope (SigmaVP, Germany). Fourier Transform Infrared (FTIR) spectrum was done on a Nicolet iS10 FT-IR spectrometer by utilizing KBr pressed disk technique.A batch study was done to determine the effect of different ratios of M2+/M3+ in LDHs at different pH 6.0 and 8.0 on the release of P from LDHs. Briefly, 0.01 g of synthesized LDH were put in a centrifuge tube mixed with 10 ml of 0.03M KNO3 at initial pH=6 and 8. Suspensions were shaken at a constant temperature (25±0.5 °C) and agitation (180 rpm) by using an incubator shaker for 8h. Phosphorus concentration in supernatant solutions was measured by vanadate yellow method at 470 nm wavelength.In order to investigate the kinetics of phosphorus release, LDH-P1 (2:1) and LDH-P2 (3:1) were used at two initial pHs of 6 and 8. First, 0.012 g of LDH sample was placed in 120 ml of KNO3 electrolyte solution (with ionic strength of 0.03 M) in an Erlenmeyer flask. The flasks were shaken for 5 to 1175 min by an incubator shaker at 100 rpm. Then the suspensions were centrifuged at a speed of 4000 rpm for 20 minutes and the phosphorus concentration was determined by the method described previously. All experiments were performed with three repetitions. Two equations (pseudo-second-order and parabolic diffusion) were used to fit the kinetics data.

According to the XRD patterns, the sharpness and reflection of diffraction planes (003) and (006) pertained to layer structures. The basal spacing as calculated by Bragg’s law (nλ = 2d sin θ) were 7.94 and 8.0 Å for Mg-Al-NO3 with M+2/M+3 2:1, 3:1 respectively. The XRD patterns of the LDHs exhibited a distinct characteristic reflection (003), which indicated that the basal spacing decreased as the Mg/Al ratio decreased (higher AEC). In addition, the decreased basal spacing is linked with a decrease in the interlayer spacing. The different basal spacing of LDH were related to the layer charge density, the content of water, and the reorientation of anions in the interlayer of LDH. The intercalation of phosphate anions into Mg/Al LDH is in adaptation with the change toward lower 2θ angles of the (001) reflections corresponding to the expansion of the basal distance d003 compared to the host Mg/Al-NO3-.Two bands of FT-IR spectrums around 3470 and 1655 cm-1 for all synthesized LDH materials designate stretching vibrations of the O-H group of hydroxide layers and the interlayer water molecules. The band vibration of phosphate was perceived at 1051 cm−1 and 1064 cm-1, reflecting the formation of inner-sphere surface complex (M-O-P) between dihydrogen phosphate ions and MgAl-LDH materials. It indicated that the phosphate exchange process may be resulted in the formation of bidentate and monodentate surface complexes. According to the SEM images, the well-crystallized and plate-like morphology were typical for layer double hydroxides. The results of the X-ray energy dispersive spectroscopy (EDS) analysis showed, the only elements that existed in the LDH-N were Mg, Al, N, and O, whereas Mg, Al, P, and O were detected in the LDH-P. The results showed that increasing the pH from 6 to 8 in the presence of 0.03 M potassium nitrate background electrolyte led to an increase in phosphorus released from both types of LDH. For example, by increasing the initial pH of suspensions from 6 to 8, the amount of cumulative phosphorus released from LDH-P1 increased from 38.59 mg kg-1 to 41.91 mg kg-1 at equilibrium. In all studied pHs, phosphorus release from LDH-P1 in background electrolyte was lower than LDH-P2. For example, at pH 6 and 8, the amount of cumulative phosphorus released from LDH-P2 was 1.46 and 1.33 times higher than LDH-P1 at equilibrium, respectively. The cumulative phosphorus release kinetics from the studied LDHs showed that the amount of phosphorus release accelerated with increasing time. Phosphorus release from LDH continued at a higher rate from 0 to 400 minutes in the first stage and at a slower rate during 400-1175 minutes. Also, based on the results, among the studied kinetic equations, pseudo-second-order and parabolic diffusion equations had the best fit on phosphorus release data.

The results of this research showed that the release of phosphorus from LDH is dependent on time, pH and the type of LDH. Based on the results of fitting the kinetics models to the experimental data, the release rate of phosphorus from LDH-P2 (3:1) was higher than that of LDH-P1 (2:1). Cumulative phosphorus release from LDH-P2 compared to LDH-P1 was 46.54, 33.61% higher at pH 6 and 8, respectively.

Trichoderma species are widely used as biological agents to control plant diseases. Chitinases are crucial in mycoparasitism and defense against other fungi or arthropods. In this study, we evaluated 41 amino acid sequences related to the Chit18-5 gene from four sections and 15 Trichoderma species. The conserved domains, motifs, and phylogenetic tree were analyzed using the InterProScan database, COBALT tool, MEME V5.5.1 software, ClustalW algorithm, and MEGA11 software. The results showed that the gene region under investigation can effectively distinguish different Trichoderma species and is an effective tool for optimizing biocontrol strategies. This study highlights the potential of exploring genetic diversity as a means of identifying new solutions for managing pests and diseases in agriculture. The putative motifs of chitinase proteins identified in this study may participate in Trichoderma antagonistic activities.

Local communities' traditional and dependent livelihood results in many parts of the Zagros ecosystem being slash‐and‐burn agricultural areas. The current study examines the destructive processes of structural components in the slash and burn agriculture in Zagros forests. Quantitative and qualitative factors of all trees were recorded through one-by-one sampling. Quantitative data include species type, a vegetative form (coppice or standard method), diameter at breast height (DBH), tree height, large diameter and small diameter of a crown, tree health, and cut and destroyed roots proportion. Violations reports of natural resources were hired during 2001-2021 to calculate the number and volume of removed trees in three sites. Samplings were taken from the diameter at the breast height in the radial direction via an increment borer to detect differences in 2021 compared to 2001. Therefore, the diameter increase was calculated. The calculating results of the canopy area in 2021 and extracting it in 2001 in the Kasehkaran, Avalviar, and Cheshmeh Phan sites showed that the canopy area has decreased from 54686 to 43180, from 15830 to 12762, and from 22232 to 19064 m2, respectively. The distribution diagram of trees frequency in the diameter classes in studied times showed that the frequency of the number of trees in the three studied areas decreased in the second period compared to the first period. The total volume in 2001 was 153, 1174.5, and 565.6 m3, respectively, which in 2021 decreased to 144, 822, and 515 m3 in the Kasehkaran, respectively the Avalviar, and Cheshmeh Pahn. The removed trees in various ways in these areas include 118, 523, and 132, respectively, over 20 years. Comparing the means results using paired t-test with a probability of 99% showed that the difference between the means of volume factor in the two periods for Avalviar and Cheshmeh Pahn and the tree crown area is significant for the studied three habitats. Although the shifting agriculture extent may seem to have remained the same, its structural degradation has occurred over time. Therefore, these areas should be specifically protected by the appropriate agencies in addition to the regular protection measures.

In order to prevent obesity it is essential to identify its determinants. This study aimed to assess the association between duration of breastfeeding and subsequent obesity among female adolescents in Najafabad, Isfahan, Iran.

In this cross-sectional study, data were collected on 550 female adolescents aged 15-18 years selected by multistage cluster random sampling from Najafabad high schools. Anthropometric measurements were made and the body mass index (BMI) was calculated. Information on duration of breastfeeding and other required variables was collected by interviewing parents using questionnaires. Overweight and obesity were defined on the basis of TOTF cut-points.

The mean (± SD) duration of breastfeeding was 19.7±8.1 months, and the prevalence of overweight and obesity 20.5% and 6%, respectively. Breastfeeding as such (that is, without considering its duration), was significantly associated with a reduced risk of overweight or obesity (25.8% for breastfed, vs 50% for non-breastfed, adolescent, P = 0.02). However, no statistically significant association was found between duration of breastfeeding and either overweight or obesity in the subjects (r= -0.007, P=0.87).

Our findings indicate that breastfeeding may reduce subsequent risk of obesity and overweight in female adolescents, although we found no association between duration of breastfeeding and adolescent overweight or obesity.

Background and aims   Respiratory diseases are one of the more Prevalence occupational diseases in colour Production industries. Because chemical hazard that are present in such  industries improving screening methods is essential. There is some kind of respiratory function  evaluation methods it seems that serial peak flowmetry has found a new place.   MethodS   In this cross sectional study we did serial peak flowmetry in 30 workers of a colour  production factory in 14days.Crude and means data were collected from each day and then were compared to another days data. Evaluation of two weeks data helped us to omit confounding   variables.So coherency of two weeks data were confirmed validity of study.   Results   Mean degree of peak flowse due to last workday in propotion of first work day were significantly different (p<0.001). This manner was repeated in data of second week(p<0.001) ;  (r=0.908). peak flow daily changes pattern showed decrease in end of the shift more than beginning  of day. 17 workers who had significant changes did not how any pathologic signs in routine annual  spirometry. Most changes were due to first workday in opposite to last workday (35±16.5 in  contrast 33.6 ±11.8)   Conclusion   According to results of this study it seems that serial peak flowmetry test is more  sensitive in screening and evaluation workers respiratory function in proportion of routine annual  spirometry.

Hypertension in one of the aggravating factors for cardiovascular complications among diabetics, which in turn leads to increased mortality among these patients. This study investigated the annual and 5-year incidence rate of hypertension in type 2 diabetic patients referring to Isfahan Endocrine and Metabolism Research Center (IEMRC).

In a prospective study, all type 2 diabetic patients with normal blood pressure, who were referred to IEMRC in 1995, underwent investigation. Age, sex, weight, height, serum cholesterol, triglycerides and HbA1c and urine protein were measured and the results recorded in addition to the history of smoking and the duration of diabetes. All measurements (including blood pressure, ophthalmologic exam) were repeated every 6 months for 5 years.

Of 770 patients, 174 (23%) were excluded because of high blood pressure at their first visit. The 5-year incidence rate was 41.5%. The mean±SD of BMI and age in hypertensive vs normotensive patients were 27.8±3.8 vs 26.2±3.8 kg/m2 (p<0.05), 52.6±10 vs 45.6±10 years (p<0.05), respectively. Differences observed among other variables were not significant. Presence of retinopathy and proteinuria at base line causes significant increase in the 5-year incidence of hypertension.

The incidence of hypertension in type 2 diabetic patients is higher in our society as compared with that seen in other studies. Age, duration of the diabetes and BMI affect the incidence of hypertension. Retinopathy and proteinuria are important risk factors of hypertension among our patients.