A machine learning approach to robustly determine director fields and analyze defects in active nematics.

Active nematics are dense systems of rodlike particles that consume energy to drive motion at the level of the individual particles. They exist in natural systems like biological tissues and artificial materials such as suspensions of self-propelled colloidal particles or synthetic microswimmers. Active nematics have attracted significant attention in recent years due to their spectacular nonequilibrium collective spatiotemporal dynamics, which may enable applications in fields such as robotics, drug delivery, and materials science. The director field, which measures the direction and degree of alignment of the local nematic orientation, is a crucial characteristic of active nematics and is essential for studying topological defects. However, determining the director field is a significant challenge in many experimental systems. Although director fields can be derived from images of active nematics using traditional imaging processing methods, the accuracy of such methods is highly sensitive to the settings of the algorithms. These settings must be tuned from image to image due to experimental noise, intrinsic noise of the imaging technology, and perturbations caused by changes in experimental conditions. This sensitivity currently limits automatic analysis of active nematics. To address this, we developed a machine learning model for extracting reliable director fields from raw experimental images, which enables accurate analysis of topological defects. Application of the algorithm to experimental data demonstrates that the approach is robust and highly generalizable to experimental settings that are different from those in the training data. It could be a promising tool for investigating active nematics and may be generalized to other active matter systems.

Light-activated microtubule-based two-dimensional active nematic.

We assess the ability of two light responsive kinesin motor clusters to drive dynamics of microtubule-based active nematics: opto-K401, a processive motor, and opto-K365, a non-processive motor. Measurements reveal an order of magnitude improvement in the contrast of nematic flow speeds between maximally- and minimally-illuminated states for opto-K365 motors when compared to opto-K401 construct. For opto-K365 nematics, we characterize both the steady-state flow and defect density as a function of applied light. We also examine the transient behavior as the system switches between steady-states upon changes in light intensities. Although nematic flows reach a steady state within tens of seconds, the defect density exhibits transient behavior for up to 10 minutes, showing a separation between small-scale active flows and system-scale structural states. Our work establishes an experimental platform that can exploit spatiotemporally-heterogeneous patterns of activity to generate targeted dynamical states.

Preparation and evaluation of a polycaprolactone/chitosan/propolis fibrous nanocomposite scaffold as a tissue engineering skin substitute.

Introduction: Recently, the application of nanofibrous mats for dressing skin wounds has received great attention. In this study, we aimed to fabricate and characterize an electrospun nanofibrous mat containing polycaprolactone (PCL), chitosan (CTS), and propolis for use as a tissue-engineered skin substitute. Methods: Raw propolis was extracted, and its phenolic and flavonoid contents were measured. The physiochemical and biological properties of the fabricated mats, including PCL, PCL/CTS, and PCL/CTS/Propolis were evaluated by scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical analysis, swelling and degradation behaviors, contact angle measurement, cell attachment, DAPI staining, and MTT assay. On the other hand, the drug release pattern of propolis from the PCL/CTS/Propolis scaffold was determined. A deep second-degree burn wound model was induced in rats to investigate wound healing using macroscopical and histopathological evaluations. Results: The results revealed that the propolis extract contained high amounts of phenolic and flavonoid compounds. The fabricated scaffold had suitable physicochemical and mechanical properties. Uniform, bead-free, and well-branched fibers were observed in SEM images of mats. AFM analysis indicated that the addition of CTS and propolis to PCL elevated the surface roughness. MTT results revealed that the electrospun PCL/CTS/Propolis mat was biocompatible. The presence of fibroblast cells on the PCL/CTS/Propolis mats was confirmed by DAPI staining and SEM images. Also, propolis was sustainably released from the PCL/CTS/Propolis mat. The animal study revealed that addition of propolis significantly improved wound healing. Conclusion: The nanofibrous PCL/CTS/Propolis mat can be applied as a tissue-engineered skin substitute for healing cutaneous wounds, such as burn wounds.

The Effect of Bonding Surface Design on Shear Bond Strength of 3D-Printed Orthodontic Attachments.

Introduction: This study compared the shear bond strength (SBS) of four innovative designs of the bonding surface of 3D-printed orthodontic attachments with conventional mesh design. Methods: In this in vitro study, the bonding surface design in different groups was as follows: Group 1, flat surface without any feature as a negative control; Group 2, concentric circles with no cuts; Group 3, concentric circles with 16 radial cuts; Group 4, concentric circles with 32 radial cuts; Group 5, small cones with a flat end and rounded edges; Group 6, mesh-based commercially available metal brackets of the maxillary central incisor (standard edgewise, Dentaurum®) as a positive control (n = 20). In Groups 1-5, attachments were designed with SolidWorks® Software and printed with a 2K DLP-LCD printer with hard tough resin (eSun®). All the samples were bonded to the restorative composite resin (Solafil®) surfaces with orthodontic composite resin (CuRAY-ECLIPSE®). The samples were examined for SBS with a universal testing machine after thermocycling (1,000 cycles of 5‒55°C). Data were analyzed with Shapiro-Wilk, one-way ANOVA, and Bonferroni tests. The statistical significance level was set at 0.05. Results: The mean SBS was significantly different between all the groups (P < 0.001) except for Groups 2 and 5 (P = 1.00) and Groups 2 and 6 (P = 1.00). Group 4 had the highest mean of SBS. Conclusion: The bonding surface design significantly influenced the SBS of orthodontic attachments. The concentric circles with 32 cuts had higher bond strength than other designs and can be suggested as a new bonding surface design for orthodontic attachments.

From disks to channels: dynamics of active nematics confined to an annulus.

Confinement can be used to systematically tame turbulent dynamics occurring in active fluids. Although periodic channels are the simplest geometries to study confinement numerically, the corresponding experimental realizations require closed racetracks. Here, we computationally study 2D active nematics confined to such a geometry-an annulus. By systematically varying the annulus inner radius and channel width, we bridge the behaviors observed in the previously studied asymptotic limits of the annulus geometry: a disk and an infinite channel. We identify new steady-state behaviors, which reveal the influence of boundary curvature and its interplay with confinement. We also show that, below a threshold inner radius, the dynamics are insensitive to the presence of the inner hole. We explain this insensitivity through a simple scaling analysis. Our work sheds further light on design principles for using confinement to control the dynamics of active nematics.

Bonding Surface Designs in Fixed Orthodontic Attachments.

Fixed orthodontic attachments/appliances work as a medium to transfer the force applied to the teeth. In bonded types, several factors affect the attachment bond strength and their clinical success. The primary approach for increasing the bond strength focused on altering the time and concentration of acid etching; however, the results showed that these changes might increase susceptibility to enamel decalcification. The bonding mechanism of orthodontic attachments may be chemical, mechanical, or a combination of both. Most attachment bonding surfaces (ABSs) have no chemical bond to resin composites. Hence, mechanical retention plays a major role. Developing more bonding surfaces by increasing the macroscopic size of the attachments has esthetic and hygienic limitations, so the ABS design plays a more important role in maintaining and improving the bond strength. In this research, different ABS designs are reviewed and categorized according to manufacturing methods and their features.

Optimization of Dendrimer Polyamidoamin Electrospun Nanofibers: Preparation and Properties.

Background: The most common polymers in the treatment of wounds are natural (e.g., polysaccharides, proteins, and peptides) and synthetic polymers (e.g., poly-glycolic acid, polyacrylic acid, polylactic acid, and polyvinyl alcohol) due to their biodegradability, biocompatibility, and their structural resemblance to the macromolecules known to the human body. Objectives: The current study aimed to develop an electrospinning method using the nanofibers of polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC)/polyamide amine (PAMAM)/tetracycline (Tet) to cover the wound. The antibacterial effect of PAMAM was also tested against E. coli and S. aureus bacteria. Materials and Methods: The morphology of the composite nanofiber was studied by a field emission scanning electron microscope. Infrared spectroscopy (FTIR) was used to characterize the nano chemical structure. Results: Nanofibers were evaluated based on the release of different amounts of the antibiotic tetracycline (1%, 3%, 5%, and 7% by weight) while preventing wound infection. The findings indicated that the highest-profile release of all nanofibers occurred early within 12 hours. It was found that nanofiber membranes loaded with 1%, 3%, and 5% tetracycline released drugs for over 28 days, while those containing 7% tetracycline released drugs for more than 14 days. Conclusions: According to the findings related to the drug release of PVA/CMC/15% PAMAM/Tet and surface morphology of the nanofibers, the optimal amount of Tet was 5%. The results of FTIR spectroscopy indicated that the tetracycline and polyamidoamine were successfully placed in nanofibers.

Prevalence of general and abdominal obesity and its relationship with opium, total opiate drugs, and chronic smoking: Fasa cohort study.

BACKGROUND AND AIMS: Obesity and drug use are two major global issues today. This study aimed to evaluate the relationship between alcohol and tobacco use with general and central obesity. METHODS: The data of the longitudinal population-based study were collected from the basis of the Fasa Cohort Study (FACS). Participants were 10141 people with 35-70 years old. Data were analyzed by SPSS 20 software. Binary logistic regression (BLR) was used for modelling. A significance level (α) less than 0.05% was considered for hypothesis testing. RESULTS: Of the total participants (N = 10104), 54.8% (n = 5539) were women. The prevalence of central obesity in terms of waist circumference (WC), waist to hip ratio (WHR), and waist to height ratio (WHtR) were calculated 48.20% (N = 4871), 79.50% (N = 8032), and 83.30% (N = 8314). The Odds Ratio (OR) adjusted of Abnormal body mass index (BMI) for Opium and chronic smoking were 0.54 (CI: 0.47-0.63) and 0.47 (CI:0.40-0.56). OR adjusted Abnormal WC for opium and chronic smoking were calculated 0.65 (CI: 0.53-0.80) and 0.57 (CI:0.46-0.72), respectively. Three variables of opium (OR = 0.54, CI: 0.46-0.64), total opiate drugs (OR = 1.46, CI:1.16-1.83) and chronic smoking (OR = 0.58, CI: 0.48-0.70) remained in the modeling for Abnormal WHR. Which were statistically significant. CONCLUSION: Significant and inverse relationships were found between obesity and opium, total opiate drugs, and chronic smoking.

Effect of different surface treatment with panaviaV5 on shear bond strength of metal brackets to silver amalgam.

BACKGROUND: This study was conducted to compare the shear bond strength (SBS) of orthodontic brackets to amalgam surfaces by two surface treatment methods, two different adhesives, and one intermediate resin and also to evaluate surface roughness after two preparation methods as well as bond failure mode. MATERIALS AND METHODS: In this in-vitro study forty-eight amalgam samples were randomly allocated to four groups. In Groups 1-3, specimens were sandblasted with 50 µm aluminum oxide, followed by application of Alloy primer in Groups 1 and 2. In Group 3 Alloy primer had not used. In Group 4, samples were prepared by silica coating using a silane coupling agent. Surface roughness analysis was performed in 10 additional samples after two surface treatments. The brackets in Group 1 were bonded with Transbond XT and those in other groups were bonded with Panavia V5. All specimens were examined for SBS following 5000 times thermocycling at 5°C-50°C. Modified adhesive remnant index was utilized for the bond failure mode. Data analysis was done by one-way analysis of variance, post hoc Tukey, Kruskal-Walli and Mann-Whitney U tests. Statistical significance was set at P < 0.05. RESULTS: The findings indicated the mean SBS were low (ranged from 0.19 to 4.66 MPa) and significantly lower in Group 3 than in Group 4 (P = 0.009). Bond failure occurred in adhesive/amalgam interface in nearly all samples. Silica coating produced significantly lower roughness than sandblast (P = 0.009). CONCLUSION: Silica coating had a significant higher bond strength than sandblast without application of Alloy primer. However compared to sandblast with Alloy primer, silica coating did not significantly improve the bond strength. Chemical bond between PanaviaV5 and sandblasted amalgam was not considerable.

Evaluation of Microleakage in Resin Composites Bonded to an Er:YAG Laser and Bur-Prepared Root and Coronal Dentin Using Different Bonding Agents.

Introduction: This study was conducted to assess the microleakage in Er:YAG laser-ablated and bur-prepared root and coronal dentin cavities using self-etch and total-etch adhesive systems. Methods: Sixty extracted caries-free human third molars were sectioned for dentin exposure. Then, two standard class V cavities were prepared in the root and coronal dentin of each tooth and allocated to one of the following conditioning groups randomly (n=12/Group): G1: Diamond bur for cavity preparation and single bond (BESB) etch-and-rinse adhesive for bonding, G2: Er:YAG laser (160 mJ, 20 Hz, 29.88 J/cm2) and SB (LESB), G3: Er:YAG laser and SB without acid etching (LSB), G4: Diamond bur and Clearfil SE Bond (BCSE) self-etch system, and G5: Er:YAG laser and Clearfil SE Bond (LCSE). The cavities were filled with Z100 composite resin. Dye penetration was assessed after thermocycling. Data analysis was done by Kruskal-Wallis and Mann-Whitney U tests. Statistical significance was set at P<0.05. Results: The results showed there were no statistically significant differences in microleakage between the two preparation methods (bur and laser) or the bonding agents applied (P>0.05). Regardless of the cavity preparation method, dye penetration was significantly higher in coronal dentin than in root dentin (P<0.05). Conclusion: The Er:YAG laser had the same efficacy as the conventional method for cavity preparation, and microleakage did not depend on the bonding agent. Microleakage was significantly higher in coronal restorations than in root restorations.

Status of Quality in Strategic Purchasing in the Health System: A Systematic Review / Estado de la calidad en las compras estratégicas en el sistema de salud: Una revisión sistemática

Introduction. Las compras estratégicas son un componente importante del financiamiento del sistema de salud. Puede mejorar la productividad, la justicia y la responsabilidad en la prestación de atención médica en caso de considerar la calidad. Este estudio, que se realizó como una revisión sistemática, tuvo como objetivo investigar el estado de la calidad en cinco dominios de compras estratégicas en el sistema de salud para responder qué, para quién, de quién, cómo comprar y cuánto comprar. Material y Métodos: Este estudio revisó sistemáticamente los artículos publicados en las bases de datos de Web of Sciences (WOS), Scopus, PubMed, Medline vía Ovid, Embase desde 2000 hasta octubre de 2019. Las palabras clave utilizadas para la búsqueda en las bases de datos incluyeron las siguientes: Sector Salud, Entrega de atención médica, garantía de calidad, mejora de la calidad y compras estratégicas. Un total de 182 artículos fueron seleccionados y revisados ​​por cuatro investigadores. Se excluyeron los artículos con contenido irrelevante. Los datos de los artículos seleccionados se analizaron mediante el método de análisis de contenido. Resultados: De los 182 artículos recopilados mediante la búsqueda en las bases de datos seleccionadas, se analizaron 16 artículos. Con base en los resultados de este estudio, las compras estratégicas en el sistema de salud resultan en la entrega de servicios con mayor calidad. Conclusión: Las compras estratégicas pueden mejorar el desempeño del sistema de salud al elegir el proveedor más apropiado y el método de pago más apropiado, junto con la equidad en la prestación de servicios de atención médica de calidad

Introducction. Strategic purchasing is an important component of financing in the health system. It can enhance productivity, justice, and accountability in the health care delivery in case of considering the quality. This study, which was conducted as a systematic review, was aimed at investigating the status of quality in five domains of strategic purchasing in the health system to answer what, for whom, from whom, how to buy, and how much to buy. Material and Methods: This study systematically reviewed the articles published in the databases of Web of Sciences (WOS), Scopus, PubMed, Medline via Ovid, Embase from 2000 to October 2019. The keywords used to search the databases included the following: Health Care Sector, Delivery of Health Care, Quality Assurance, Quality Improvement, and Strategic Purchasing. A total of 182 articles were selected and reviewed by four researchers. Articles with irrelevant content were excluded. Data of the selected articles were analyzed using the content analysis method. Results: Of the 182 articles collected through searching the selected databases, 16 articles were analyzed. Based on the results of this study, strategic purchasing in the health system results in the delivery of services with higher quality. Conclusion: Strategic purchasing can enhance the performance of the health system through choosing the most appropriate provider and the most appropriate payment method, along with equity in providing quality health care services

Inhibitory effects of ethanolic, methanolic, and hydroalcoholic extracts of olive (Olea europaea) leaf on growth, acid production, and adhesion of Streptococcus mutans.

BACKGROUND: Usage of chemical mouthwashes for controlling dental caries can end to some side effects such as oral biological imbalance. Recently, using natural derivatives such as herbs, presented to overcome such adverse effects. Due to antibacterial property of olive leaf extracts (Olea europaea), this study conducted in order to evaluate bacteriocidal, anti-acid production, and anti-adhesion effects of olive leaf ethanolic, methanolic, and hydroalcoholic extracts on Streptococcus mutans. MATERIALS AND METHODS: In this in vitro study, nine strains of S. mutans (PTCC1683) were used. Maceration methods were done in order to provide the olive leaf ethanolic, methanolic, and hydroalcoholic extracts. The antibacterial activities evaluated by macrodilution and disc diffusion method in different concentrations (3.25%-100%). Acid production and adhesion of bacterial strains also were evaluated. The obtained data were analyzed by analysis of variance method using SPSS software. P < 0.05 was considered as statistically significant. RESULTS: The minimum inhibitory concentration and minimum bactericidal concentration for ethanolic, methanolic, and hydroalcoholic olive leaf extracts on S. mutans are 12%-25%, 50%-75%, and 12%-25%, respectively. In addition, inhibition zone of S. mutans significantly increased in higher concentration (ethanolic and methanolic extracts: P = 0.004; hydroalcoholic extract: P = 0.003). The acid production and adhesion significantly decreased by increase in the concentration (P < 0.001). CONCLUSION: In general, olive leaf ethanolic, methanolic, and hydroalcoholic extracts induce growth inhibition, acid production, and adhesion of S. mutans. Consequently, it can be used as a natural preservative in the food industry, as well as in the production of commercial products such as chewing gum, chocolate, and toothpaste to prevent dental caries.

Co-production of knowledge and adaptation to water scarcity in developing countries.

Dwindling of freshwater resources is a harsh reality of the arid and semi-arid regions of the world and climate change is expected to deteriorate their situation through major reduction of freshwater supplies. Co-production of knowledge, through active negotiation of experts, government and local stakeholders has been used as a strategy to adapt to water scarcity. However, in many developing countries, co-production of knowledge is not common and adaptation efforts rarely reflects the plurality of involved knowledge sources and actors. Given the urgent need of transition towards water-efficient agricultural practices, the Iran's government applied the knowledge co-production approach and implemented an integrated participatory crop management (IPCM) project in the Bakian village, Fars province. The objectives of this study were to analyze the knowledge co-production process, identify the factors contributing to adoption of the co-produced knowledge and investigate the corresponding social, economic and environmental impacts. A mixed-method research was conducted comprising a case study on 19 informants selected using purposive sampling and a survey of 150 rice producers selected through systematic random sampling. The results indicated the relevance and pertinence of knowledge co-production in recognizing the real problems of the rice producers and suggesting some potential adaptive strategies. Though a wide range of natural, financial, technical, institutional and structural constraints restricted adoption of the proposed adaptive strategies, application of the co-produced knowledge significantly increased water productivity, ensured higher yields and farm-based sustainable livelihoods, and enhanced resilience of the farm households under water scarcity. Some recommendations and implications are offered to increase adaptation of farm families to water scarcity.

Antifungal effect of Atorvastatin against Candida species in comparison to Fluconazole and Nystatin.

BACKGROUND AND AIMS: Atorvastatin is a plasma cholesterol-lowering drug which applies antifungal effects by inhibiting the production of yeast cell wall ergostrol. The aim of present study was to investigate in-vitro susceptibility of candida species to atorvastatin, in comparison to nystatin and fluconazole. METHODS: Minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) were determined using serial dilution. Candida strains isolated from 35 patients receiving cancer chemotherapy in Isfahan, Seyyed-al-Shohada Hospital and analyzed by Kruskal-Wallis and Mann Whitney statistical methods. RESULTS: Candida isolates included 5 strains, C. albicans, C. glabrata, C. kefyr, C. stellatoidea and C. krusei. All five strains appeared to be resistant to nystatin and fluconazole but sensitive to atorvastatin with no statistically significant difference. The MFC of atorvastatin was significantly lower in comparison to both nystatin and fluconazole for all five strains (p value<0.05). There was no significant difference between the MFCs of 5 strains for fluconazole and atorvastatin. However, MFC of nystatin differed significantly for C. albicans and C. kefyr (p=0.007). CONCLUSION: The results showed that all strains were sensitive to atorvastatin and resistant to nystatin and fluconazole. Atorvastatin MIC for C. albicans, C. krusei and C. stellatoidea was equivalent to its serum level used to treat hyperlipidemia and was above such level for both C. glabrata and C. kefyr.

The Relationship between the Phases of the Menstrual Cycle on the Incidence and Severity of Headache after Spinal Anesthesia.

Introduction Headache after spinal anesthesia is a common complication, which is caused after dural puncture due to discharge of cerebrospinal fluid and reduction in the volume and pressure. Studies have shown that a variety of factors are involved including needle shape, needle size, patient's sex, age, duration of surgery, history of spinal anesthesia, and history of headaches. One possible factor is the phase of the menstrual cycle. Many studies have investigated the effect of the menstrual cycle on factors such as postoperative nausea, vomiting, propofol injection pain, and sore throat after intubation. Also, many studies have investigated the effect of different phases of the menstrual cycle on migraine headaches. Therefore, we decided to investigate the effect of different phases of the menstrual cycle on headache after spinal anesthesia. Materials and Methods To determine the relationship between headache after spinal anesthesia and menstrual cycle, the study included all the patients undergoing spinal anesthesia in Shohada Ashayer and Asalian Hospitals of Khorramabad. This cohort study included 279 patients, and data collection tool was a questionnaire. The data from the questionnaire included age, menstrual phase, surgical procedures, pain location, pain intensity, history of spinal anesthesia, history of headache, and headache after spinal anesthesia. Results There was no statistically significant difference between the location of headache, the history of spinal anesthesia, the location of headache, the history of headache, and menstrual phase. Conclusion Considering the high incidence of postdural puncture headache in follicular phase, it is recommended that patients with a high risk of headaches undergo spinal anesthesia and surgery in the luteal phase.

Heavy metals content and distribution in basil (Ocimum basilicum L.) as influenced by cadmium and different potassium sources.

Despite the fact that cadmium (Cd) is a non-essential element for plants, it can influence nutrients and affect human health. Potassium (K) can influence the transportation of heavy metals (HMs) in soil-plant systems. Here, a greenhouse experiment was conducted to evaluate the effect of Cd and K fertilizers on the different partitioning forms of HMs, their concentrations, uptake in the shoots and roots of Ocimum basilicum. Treatments comprised 2 levels of Cd (0 and 40 mg kg-1) and three levels of K (0, 100, and 200 mg kg-1) from three sources, i.e. KCl, K2SO4, and K-nano-chelate. 40 mg Cd kg-1 increased the shoot (above ground parts) Cd concentration. Addition of K as KCl, K2SO4, and K-nano-chelate increased the presence of Cd in shoots by 86, 82 and 76%, respectively, compared to the control. Using the nano-chelate of K can increase the accumulation of Cd in plants grown on contaminated soils to lesser content than that of the other forms of K. Application of 40 mg Cd kg-1 reduced the concentration of Zn, Cu, and Mn in the shoot, but increased shoot Fe concentration. Transfer factor (TF), which is the ratio of metal concentration in shoot to its concentration in root, of the studied HMs, was significantly affected by Cd and K treatments. Therefore, the proper form and dose of chemical fertilizers should be applied in Cd-contaminated soils.

Perinatal outcome in pregnancy with polyhydramnios in comparison with normal pregnancy in department of obstetrics at Shiraz University of Medical Sciences.

OBJECTIVE: Polyhydramnios can lead to maternal and fetal complication during pregnancy, so diagnosis and management can decrease some perinatal complications. STUDY DESIGN: One hundred and fourteen singleton pregnancies were diagnosed with idiopathic polyhydramnios in the department of obstetrics at Shiraz University of Medical Sciences between January 2000 and January 2011 and were compared with 114 normal pregnancies for their perinatal outcome. Variables include birth weight, admission to neonatal intensive care unit (NICU), meconium staining, respiratory distress, fetal death, neonatal death, low 1-min and 5-min APGAR score, primary cesarean section (C/S), preterm delivery (<37 weeks), postpartum bleeding, and placental abruption. RESULTS: Low birth weight (<2500 g), macrosoma (>4000 g), NICU admission, fetal distress, fetal death, lower 1-min and 5-min APGAR score, preterm delivery, and neonatal death were higher in the case group. However, meconium staining and malpresentation were equal between the two groups. Except for prematurity and 1-min and 5-min APGAR scores, there were no significant differences in other maternal or fetal outcomes considering the severity of polyhydramnios. CONCLUSION: Idiopathic polyhydramnios should be considered as a high-risk pregnancy that warrants close surveillance. More studies should be done to detect the best time and interval of fetal surveillance in these patients. Chromosomal and torch studies can determine the definite cause of polyhydramnios.

Physical and Chemical Properties of CEM Cement Mixed with Propylene Glycol.

INTRODUCTION: the aim of the present study was to evaluate the influence of propylene glycol (PG) on the flowability, microhardness, pH and calcium ion release of calcium-enriched mixture (CEM). METHODS AND MATERIALS: CEM cement was mixed with different proportions of PG, as follows: group 1,100% CEM liquid (CL); group 2, 100% PG; group 3, 50% PG and group 4, 20% PG. For assessment of flowability, methodology of ADA Specification No. 57 was applied. For measuring microhardness, 80 cylindrical molds (6×4 mm) were filled with CEM cement and divided into 2 subgroups (4, 21 days) and tested using Vickers Test. Data were analyzed using the one-way ANOVA test and Tukey's post hoc and student's t test. In order to check pH and calcium release, the mixed cements were placed in cylindrical molds (5×2 mm). After 3, 24, 72 and 168 h, pH determined by a pH meter and the calcium release was measured by an atomic absorption spectrophotometer. Data were analyzed using the repeated measure ANOVA, one way ANOVA test and Tuckey's post hoc test. RESULTS: The present study showed that the presence of PG did not affect the flowability. With the elapse of time, microhardness was significantly increased in all groups except CL group. Regardless of time, samples with 50% PG showed the lowest pH value which was significantly different from other groups (P<0.05) and samples with 100% and 20% PG showed significantly higher calcium ion release compared to other group. CONCLUSION: addition of PG did not have any positive or negative effect on the flowability and pH of CEM cement but increased its microhardness in long term. Calcium ion release also increased in the concentration of 20% and 100%.

Stubborn Disease in Iran: Diversity of Spiroplasma citri Strains in Circulifer haematoceps Leafhoppers Collected in Sesame Fields in Fars Province.

Spiroplasma citri is a bacterial pathogen responsible for the economically important citrus stubborn disease. Sesame and citrus seeds serve as hosts for both S. citri and its leafhopper vector Circulifer haematoceps. To evaluate whether sesame could act as a reservoir for citrus-infecting strains or not, the genetic diversity among S. citri strains found in leafhoppers collected in citrus and citrus-free sesame fields was investigated. Among 26 periwinkle plants exposed to the collected C. haematoceps leafhoppers, 12 plants developed typical stubborn symptoms. All symptomatic periwinkles were polymerase chain reaction positive using S. citri-specific primer pairs targeting the spiralin and P89 genes. Phylogenetic trees based on spiralin gene sequence analysis indicated that the novel field-collected strains clustered with those belonging to two formerly defined S. citri groups (groups 6 and 1). In addition, our results strongly suggest that group 1 strains could be transmitted from sesame-infected plants to citrus trees by C. haematoceps, while group 6 strains may not infect citrus trees.

Sexual Dimorphism of Maxillary Sinus Dimensions Using Cone-Beam Computed Tomography.

Sex determination of unknown persons plays an important role in forensic medicine. Cone-beam computed tomography (CBCT) is an excellent imaging modality for accurate measurement of maxillary sinus dimensions. This study aimed to evaluate whether maxillary sinus measurements on CBCT scans can be applied for sex determination. The width, length, and height of maxillary sinuses in CBCT images of 100 patients (50 males and 50 females) were measured. Student's t-test and discriminant function analysis were used to compare differences in the measured parameters between males and females. The correct predictive accuracy rate of sex determination was 78% in females and 74% in males with overall accuracy of 76%. Based on discriminant analysis, the most pronounced variable in differentiation of sex groups was maxillary sinus height. This study suggests that maxillary sinus measurements can be valuable for sex determination in forensic investigation, especially for cases in which other traditional methods are not applicable.