35 research outputs found

    Effect of akyl chain length, flow, and temperature on the corrosion inhibition of carbon steel in a simulated acidizing environment by an imidazoline-based inhibitor

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    An imidazoline, 2-heptadecyl-1-[2-(octadecanoylamino)ethyl]-2- imidazoline (QSI) with -C17H35 as the tail chain length was synthesized, characterized, and studied as corrosion inhibitor for low carbon steel in 15% HCl solution under static and hydrodynamic conditions. Influence of addition of KI, temperature, and chain length of pendant hydrocarbon on inhibition efficiency (η) was also examined. It is found that, QSI exhibits a mixed type behavior but fairly inhibited the corrosion of low carbon steel in the studied medium. The maximum concentration studied (400 mg/L) afforded η of <50%. Addition of KI to QSI synergistically enhanced the corrosion inhibition performance of QSI, upgrading the η to approximately 90%. Increase in the system temperature increases the η of both QSI and QSI + KI. From the variation of η with temperature and the calculated corrosion kinetic parameters, chemical adsorption is proposed as the adsorption mechanism of the additives. QSI performs better under hydrodynamic condition than static condition. However, the corrosion resistance of the metal decreases at rotation speed higher than 1000 rpm. Inhibition efficiency of imidazoline decreases as the length of the hydrocarbon pendant chain increases. Imidazoline compounds with -C13H27 and - C15H31 as the length of the pendant group hydrocarbon perform better than QSI with -C17H35

    Cysteine dependence of Lactobacillus iners is a potential therapeutic target for vaginal microbiota modulation

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    Vaginal microbiota composition affects many facets of reproductive health. Lactobacillus iners-dominated microbial communities are associated with poorer outcomes, including higher risk of bacterial vaginosis (BV), compared with vaginal microbiota rich in L. crispatus. Unfortunately, standard-of-care metronidazole therapy for BV typically results in dominance of L. iners, probably contributing to post-treatment relapse. Here we generate an L. iners isolate collection comprising 34 previously unreported isolates from 14 South African women with and without BV and 4 previously unreported isolates from 3 US women. We also report an associated genome catalogue comprising 1,218 vaginal Lactobacillus isolate genomes and metagenome-assembled genomes from >300 women across 4 continents. We show that, unlike L. crispatus, L. iners growth is dependent on L-cysteine in vitro and we trace this phenotype to the absence of canonical cysteine biosynthesis pathways and a restricted repertoire of cysteine-related transport mechanisms. We further show that cysteine concentrations in cervicovaginal lavage samples correlate with Lactobacillus abundance in vivo and that cystine uptake inhibitors selectively inhibit L. iners growth in vitro. Combining an inhibitor with metronidazole promotes L. crispatus dominance of defined BV-like communities in vitro by suppressing L. iners growth. Our findings enable a better understanding of L. iners biology and suggest candidate treatments to modulate the vaginal microbiota to improve reproductive health for women globally

    Malaria Situation and Anopheline Mosquitoes in Qom Province, Central Iran

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    Background: The aims of this study was to analysis the current situation of malaria and to find the distribution of anopheline mosquitoes, as probable vectors of the disease, in Qom Province, central Iran. Methods: This study was carried out in two parts. First stage was data collection about malaria cases using recorded documents of patients in the Province health center, during 2001–2008. The second stage was entomological survey conducted by mosquito larval collection method in 4 villages with different geographical positions in 2008. Data were analyzed using Excel software. Results: Of 4456 blood slides, 10.9% out were positive. Most of cases were imported from other countries (90.4%), mainly from Afghanistan (56.5%) and Pakistan (16.3%). Slide positive rate showed a maximum of 16.9% and a minimum of 2.9% in 2008 and 2007, respectively. Plasmodium vivax was causative agent of 93.75% of cases, fol­lowed by P. falciparum (6.25%). More than 15 years old age group contained the most malaria reported cases (66.7%). Two Anopheles species, An. superpictus and An. claviger were collected and identified. This is the first report of Anopheles claviger in Qom Province. Conclusion: Malaria is in the control stage in Qom Province. The rate of local transmission is very low (only 1 case), shows Anopheles superpictus, as the main malaria vector of central part of Iran, can play its role in malaria transmission in the area

    Fauna and Monthly Activity of Sand Flies at Zoonotic Cutaneous Leishmanianisis Focus in Qomrooddistrict of Qom Province in 2009

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    Background and Objectives: Zoonotic cutaneous leishmaniasis (ZCL) is a parasitological disease transmitted by female sand flies. There are several endemic foci of disease in different parts of Iran. The disease is mostly reported from central part of Qom Province including the villages Ghanavat and Qomrood. It is clear that knowledge on sand flies ecologyhas the main role in planning the control of cutaneous leishmaniasis (ZCL). This study was carried out to determinecutaneous leishmaniasis vectors in Gomrood district of Qom provincein 2009. Methods: The present study was a descriptive, cross-sectional one conducted on sand flies (the leishmaiosis vectors). It was carried out in Qomrood area of central district of Qom province during 2009. Sand flies were collected biweekly from indoors (bed rooms, stables, etc.) and outdoors-rodent burrows of three villages in Gomrood district, using 180 sticky traps (castor oil coated white paper 20 x 32 cm) from the beginning (May) to the end (November) of the active season. For species identification, sand flies were mounted in Puri’s medium and identified after 24 hours using the keys of Theodor and Mesghali (1964).Results: A total of 10252 adult sand flies (4578 from indoors and 5674 from outdoors) were collected and identified during May and November 2009. The following seven species were found in indoors: Phlebotomuspapatasi (86.1%), p. salehi (0/021%), P. sergenti (1/74%), p. caucasicus (1/26%), p. alexandri(0/24%), Sergentomyiasintoni (10/35%) and S. theodori(0/26%). The collected species of oudoors were Phlebotomuspapatasi (54/67%), P. sergenti (0/35%), p. alexandri(0/035%), S. sintoni (44/02%) S. dentata (0/21%) S. clydei (0/19%), S. theodori (0/46%) and S. pawlowski (0/05%). The most common sand flies in indoors and outdoors resting places were P. papatasi and S. sintoni. P. salehi was the lowest collected species in Gomrood district. The active peaks of sand flies were observed in late May and late August.The sex ratio i.e. number of males/100 females of P. papatasi was calculated to be 241.5 and 307.3 in indoors and rodent burrows, respectively. Conclusion: Our entomological survey showed that P. papatasi was the dominant species in indoors and outdoors. It seems this species can be probable vector for ZCL in the study area. Nevertheless, it is necessary that more studies are suggested (specially using molecular methods) in order to determinethe proven vector (s)

    Symptomatic Compression of Right Iliac Vein After Right Iliac Artery Stent Placement

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    Right lower extremity edema can be a presenting symptom of iliocaval compression syndrome, even in the absence of deep vein thrombosis. It has been reported in idiopathic and rarely, iatrogenic, cases secondary to variant anatomy, arterial stents, and bony hardware. Classically seen in the more confined left common iliac vein as May-Thurner syndrome, it is rare on the right side. We report an unusual case of acute right common iliac vein compression after right iliac stent placement leading to symptomatic right leg edema. Venous stenting resulted in resolution of symptoms at the 6-month follow-up

    Molecular Detection of Leishmania infantum in Naturally Infected Phlebotomus perfiliewi transcaucasicus in Bilesavar District, Northwestern Iran

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    Background: Visceral leishmaniasis is caused by Leishmania infantum, transmitted to humans by bites of phle­botomine sand flies and is one of the most important public health problems in Iran. To identify the vector(s), an investiga­tion was carried out in Bilesavar District, one of the important foci of the disease in Ardebil Province in northwest­ern Iran, during July-September 2008. Methods: Using sticky papers, 2,110 sand flies were collected from indoors (bedroom, guestroom, toilet and stable) and outdoors (wall cracks, crevices and animal burrows) and identified morphologically. Species-specific amplifica­tion of promastigotes revealed specific PCR products of L. infantum DNA. Results: Six sand fly species were found in the district, including: Phlebotomus perfiliewi transcaucasicus, P. pa­patasi, P. tobbi, P. sergenti, Sergentomyia dentata and S. sintoni. Phlebotomus perfiliewi transcaucasicus was the domi­nant species of the genus Phlebotomus (62.8%). Of 270 female dissected P. perfiliewi transcuacasicus, 4 (1.5%) were found naturally infected with promastigotes. Conclusion: Based on natural infections of P. perfiliewi transcaucasicus with L. infantum and the fact that it was the only species found infected with L. infantum, it seems, this sand fly could be the principal vector of visceral leishmani­asis in the region.  
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