Review of the Influence of non-singular higher order terms on the stress field of thin welded lap joints and small inclined cracks in plates

In stress analysis of cracked plates, alongside the stress intensity factor which quantifies the singular stress component perpendicular to the crack plane, the role played in crack growth by the constant term parallel to the crack plane, called the T-stress, has been widely investigated by many researchers. There are, however, cases of practical interest where the influence on the stress field of the higher order terms in the series expansion for the crack tip stress field, is not negligible. The main aim of the present investigation is to present and apply a set of equations able to describe more accurately the stress components for those cases where the mode I and mode II stress intensity factors used in combination with the T-stress are unable to characterise with sufficient precision the complete stress field ahead the crack tip. The starting point is represented by the Williams’ solution (Williams, 1957) where stresses as expressed in terms of a power series. An example is investigated of a thin-thickness welded lap joint characterized by various joint width to thickness ratios, in the range of d/t ranging from 0.5 to 5. The present paper indicates that the local stresses as well as the strain energy averaged over a control volume which embraces the slip tip, can be evaluated with satisfactory precision only by taking into account a further four terms besides KI, KII and T-stress

Green Synthesized Silver Nanoparticles as Potent Antifungal Agent against Aspergillus terreus Thom

Medicinal plants are composed of a rich pool of biomolecules and have been increasingly recognized for their antimicrobial properties; however, increasing concerns have been put on the bioavailability features. Thus, this study is aimed at exploring the synthesis and characterization of silver nanoparticles synthesized by Chenopodium album L. leaf extract and assessing the antifungal activity against Aspergillus terreus Thom. Plant extract was prepared in methanol to synthetize silver nanoparticles, which were then characterized by Scanning Electron Microscopy (SEM), UV-Visible spectroscopy, and particle size analysis. UV-Visible analysis indicated maximum absorption at 378 nm, and an average particle size was observed as 25.6 nm. Oval to hexagonal shape was observed by SEM. Antifungal activity of silver nanoparticles (1, 1.5, 2, 2.5, 3, and 3.5%) was addressed against A. terreus biomass. At 3.5%, silver nanoparticles revealed to be highly effective, leading to 92% retardation in fungus growth. In next phase, various organic fractions, viz., chloroform, n-butanol, n-hexane, and ethyl acetate, were obtained from plant methanol extract, and the corresponding silver nanoparticles were prepared. These fractions were also assessed for antifungal activity, and n-hexane fraction led to 64% inhibition in A. terreus biomass. Following gas chromatography-mass spectrometry (GC-MS), 18 compounds were identified, namely, 1,3-cyclopentadiene-5-(1 methylethylidene and o-xylene), ethyl benzene, octadecane, nonane, decane, 2-methylheptane, n-hexadecane, 2-methylheptane, and eicosane, along with carbonyl compounds (4,4-dimethyl-3-hexanone) and phenols, like stearic acid, propionic acid hydrazide, and 2,4-di-T-butylphenol. These findings proved that C. album silver nanoparticles are highly effective against A. terreus.N.C.-M. acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017)

Analgesic effects of intravenous ketamine during spinal anesthesia in pregnant women undergone Caesarean section; a randomized clinical trial

Suitable analgesia after cesarean section helps mothers to be more comfortable and increases their mobility and ability to take better care of their infants. Objectives: Pain relief properties of ketamine prescription were assessed in women with elective cesarean section who underwent spinal anesthesia with low dose intravenous ketamine and midazolam and intravenous midazolam alone. Patients and Methods: Sixty pregnant women scheduled for spinal anesthesia for cesarean section were randomized into two study groups. Ketamine (30 mg) + midazolam (1 mg = 2CC) or 1mg midazolam (2CC) alone, was given immediately after spinal anesthesia. Pain scores at first, second and third hours after CS operation, analgesic requirement and drug adverse effects were recorded in all patients. Results: Ketamine group had significant pain relief properties in compare with control group in first hours after cesarean section (0.78 ± 1.09 vs. 1.72 ± 1.22, VAS score, P = 0.00). Total dose of meperidine consumption in women of ketamine group was significantly lower than women of control group (54.17 ± 12.86 vs. 74.44 ± 33.82 mg, P = 0.02). There were no significant drug side effects in participated patients. Conclusions: Intravenous low-dose ketamine combined with midazolam for sedation during spinal anesthesia for elective Caesarean section provides more effective and long lasting pain relief than control group. © 2013 Iranian Society of Regional Anesthesia and Pain Medicine

Evaluation of antifungal activities of the essential oil and various extracts of Nigella sativa and its main component, thymoquinone against pathogenic dermatophyte strains

Objective. — Plant extracts and plant-derived compounds are valuable sources as folk medicine for the treatment and prevention of a wide range of diseases including infectious diseases. In the present study, the antifungal activities of the essential oil and various extracts Nigella sativa and its active principle, thymoquinone against Trichophyton mentagrophytes, Microsporum canis and Microsporum gypseum as pathogenic dermatophyte strains have been evaluated. In addition, the cytotoxic effects of N. sativa against murine macrophage cells were determined. Materials and methods. — In this study, the antifungal activity was studied by disk diffusion method and assessment of minimum inhibitory concentration (MIC) of extracts using broth macrodilution method. In addition, the cytotoxic activity of N. sativa was evaluated by colorimetric assay (MTT). The components of the N. sativa essential oil were also identified by gas chromatography/mass spectroscopy (GC/MS) analysis. Results. — The results showed that the essential oil and various extracts of N. sativa particularly thymoquinone have potent antifungal effects on T. mentagrophytes, M. canis and M. gypseum as pathogenic dermatophyte strains. In the assessment of the cytotoxicity activity, it could be observed that N. sativa had no significant cytotoxicity in the murine macrophages at low concentrations. While, thymoquinone in comparison with essential oil and various extracts of N. sativa showed higher cytotoxicity on murine macrophage cells. In the GC/MS analysis, thymoquinone (42.4%), p-cymene (14.1%), carvacrol (10.3%) and longifolene (6.1%) were found to be the major components of N. sativa essential oil. Conclusion. — The findings of this study suggest a first step in the search of new antidermatophytic drugs and aid the use of N. sativa seeds in the traditional medicine for dermatophytic infections

Antibacterial activity of some Lamiaceae species against Staphylococcus aureus in yoghurt-based drink (Doogh)

Doogh is a dairy drinkable fermented product, whose shelf-life and quality is mostly affected by bacteria such as Staphylococcus spp. This study investigated the antibacterial activity of essential oils (EOs) from Thymus vulgaris L., Mentha piperita L. and Ziziphora tenuior L., alone or in combination, against Staphylococcus aureus in industrial doogh. A three-level and three-variable face centered central composite design experiment was used. Results showed that EOs significantly inhibited S. aureus growth after 1 and 7 days of storage. According to the model, the maximum inhibition was obtained in the presence of 0.2% of EO, independently of the type, and no synergistic or additive effects were observed. Slightly lower S. aureus survivals were observed at the maximum concentration of Z. tenuior EO. In spite of the antimicrobial activity of these EOs, further research is needed to assess their performance in food matrix and, in particular, in dairy product

Medicinal plants used in the treatment of human immunodeficiency virus

Since the beginning of the epidemic, human immunodeficiency virus (HIV) has infected around 70 million people worldwide, most of whom reside is sub-Saharan Africa. There have been very promising developments in the treatment of HIV with anti-retroviral drug cocktails. However, drug resistance to anti-HIV drugs is emerging, and many people infected with HIV have adverse reactions or do not have ready access to currently available HIV chemotherapies. Thus, there is a need to discover new anti-HIV agents to supplement our current arsenal of anti-HIV drugs and to provide therapeutic options for populations with limited resources or access to currently efficacious chemotherapies. Plant-derived natural products continue to serve as a reservoir for the discovery of new medicines, including anti-HIV agents. This review presents a survey of plants that have shown anti-HIV activity, both in vitro and in vivo

Частота возникновения и факторы риска развития хронического отторжения при остром отторжении трансплантированной печени у детей

Background. Chronic graft rejection (CR) represents an increasing concern in pediatric liver transplantation (LT). Risk factors of CR in this population are uncertain. In present study, we aimed to ascertain if clinical parameters could predict the occurrence of CR in LT children.Methods. We retrospectively analyzed the results from 47 children who had experienced acute hepatic rejection in Namazee hospital, Shiraz, Iran during 2007–2017.Results. Out of 47 children, 22 (46.8%) and 25 (53.2%) were boys and girls respectively. Ascites, gastrointestinal bleeding, and spontaneous bacterial peritonitis were observed in 20 (44.4%), 14 (31.1%), and 4 (9.1%) respectively. Posttransplant vascular and biliary complications were observed in 3 (7%) and 4 (9.3%) cases respectively. The mean time from LT to normalization of liver enzymes was 14.2 ± 7.5 days. The mean of acute rejection episodes was 1.4 ± 0.6 (median = 1 (22, 46.8%), range of 1–3). Six (12.7%) patients experienced CR. The mean time from LT to CR was 75 ± 28.4 days. A significant association was found between CR and patients’ condition (being inpatient or outpatient) before surgery (P = 0.03). No significant relationship was found between CR and post-transplant parameters except for biliary complications (P = 0.01). Both biliary complication (RR = 33.7, 95% CI: 2.2–511, P = 0.01) and inpatient status (RR = 10.9, 95% CI: 1.1–102.5, P = 0.03) significantly increased the risk of CR.Conclusion. Being hospitalized at the time of LT, and development of biliary complications might predict risk factors for development of CR in LT children.Актуальность. Хроническое отторжение (ХО) трансплантата становится все более серьезной проблемой при трансплантации печени (ТП) у детей. Факторы риска ХО в этой популяции остаются неопределенными. В настоящем исследовании мы стремились выяснить, можно ли спрогнозировать возникновение ХО у детей с ТП по клиническим параметрам.Методы. Мы провели ретроспективный анализ 47 случаев острого отторжения трансплантата печени у детей, прооперированных в больнице Намази (г. Шираз, Иран) в период с 2007-го по 2017 год.Результаты. В исследование включили 47 детей: 22 (46,8%) мальчика и 25 (53,2%) девочек. Асцит, желудочно-кишечное кровотечение и спонтанный бактериальный перитонит наблюдались в 20 (44,4%), 14 (31,1%) и 4 (9,1%) случаях соответственно. Посттрансплантационные сосудистые и билиарные осложнения отмечались в 3 (7%) и 4 (9,3%) случаях соответственно. Показатели печеночных ферментов нормализовались в среднем через 14,2 ± 7,5 дня после ТП. Среднее количество эпизодов острого отторжения составило 1,4 ± 0,6 (медиана = 1 (22; 46,8%), диапазон 1–3). У 6 (12,7%) пациентов наблюдалось ХО. Среднее время от ТП до ХО составило 75 ± 28,4 дня. Мы выявили статистически значимую корреляцию между ХО и предоперационным периодом (нахождение в стационаре или амбулаторная подготовка, р = 0,03). ХО статистически значимо коррелировало с наличием билиарных осложнений (р = 0,01), другие послеоперационные факторы статистически значимо на него не влияли. Билиарные осложнения (ОР = 33,7, 95% ДИ 2,2–511, р = 0,01) и предоперационный статус пациента (ОР = 10,9, 95% ДИ 1,1–102,5, р = 0,03) значительно повышали риск ХО.Заключение. Госпитализация при подготовке к трансплантации и раннее выявление билиарных осложнений могут предотвратить развитие ХО трансплантата у детей после ТП

Nitric oxide induction as a novel immunoepidemiological target in malaria-infected patients from endemic areas of the Islamic Republic of Iran

Objective. Malaria has been prevalent for a long time in Iran and continues to be a health problem despite substantial control programs. In addition to numerous cytokines, nitric oxide (NO) is thought to be a key molecule and a novel target of malaria immunopathology. Material and methods. The objective of this research was to measure reactive nitrogen intermediates (RNI) as stable metabolites of NO induction in plasma of malaria-infected patients in Iran. In this study, 235 blood samples from malaria patients and 80 blood samples from healthy controls were randomly collected from different malarial endemic provinces of Iran, located in southeastern (Sistan & Balouchestan, Hormozgan, Kerman) and northwestern (Ardabil) areas. The involvement of NO in malaria patients has been investigated by statistical analysis of RNI values. Griess micro assay (GMA) was used during Plasmodium vivax, P. falciparum and mixed infections, in order to evaluate whether RNI changes are related to the provincial areas, parasite strains, clinical symptoms and age and gender parameters. Results. The results showed a significant increase of RNI level in malaria patients compared with the control groups of Ardabil (pv0.01), Sistan & Balouchestan, Hormozgan and Kerman (pv0.001) provinces. The level of RNI was higher in mixed plasmodial infection than in single infection. Conclusions. The high level of RNI was dependent on the type of infection, the plasmodia strain, the clinical symptoms, the age groups and the endemic provinces. Although, this study did not clarify the pathogenic and/or protective role of NO in malaria, our findings provide a novel immunoepidemiological aspect of basal NO production in patients with malaria in endemic areas in Iran

Chemical Composition, Biological Activity, and Health-Promoting Effects of Withania somnifera for Pharma-Food Industry Applications

The Withania genus comes from the Solanaceae family and includes around 23 species, spread over some areas of the Mediterranean, Asia, and East Africa. Widely used in traditional medicine for thousands of years, these plants are rich in secondary metabolites, with special emphasis on steroidal lactones, named withanolides which are used as ingredients in numerous formulations for a plethora of diseases, such as asthma, diabetes, arthritis, impotence, amnesia, hypertension, anxiety, stress, cancer, neurodegenerative, and cardiovascular diseases, and many others. Among them, Withania somnifera (L.) Dunal is the most widely addressed species from a pharmacological and agroindustrial point of view. In this sense, this review provides an overview of the folk uses, phytochemical composition, and biological activity, such as antioxidant, antimicrobial, anti-inflammatory, and cytotoxic activity of W. somnifera, although more recently other species have also been increasingly investigated. In addition, their health-promoting effects, i.e., antistress, anxiolytic, adaptogenic, antirheumatoid arthritis, chemoprotective, and cardiorespiratory-enhancing abilities, along with safety and adverse effects are also discussed.N. C. -M. acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017)