Surfactant-driven optimization of iron-based nanoparticle synthesis: a study on magnetic hyperthermia and endothelial cell uptake.

This work examines the effect of changing the ratio of different surfactants in single-core iron-based nanoparticles with respect to their specific absorption rate in the context of magnetic hyperthermia and cellular uptake by human umbilical vein endothelial cells (HUVEC). Three types of magnetic nanoparticles were synthesized by separately adding oleic acid or oleylamine or a mixture of both (oleic acid/oleylamine) as surfactants. A carefully controlled thermal decomposition synthesis process led to monodispersed nanoparticles with a narrow size distribution. Spherical-shaped nanoparticles were mainly obtained for those synthesized with oleic acid, while the shape changed upon adding oleylamine. The combined use of oleic acid and oleylamine as surfactants in single-core iron-based nanoparticles resulted in a substantial saturation magnetization, reaching up to 140 A m2 kg-1 at room temperature. The interplay between these surfactants played a crucial role in achieving this high magnetic saturation. By modifying the surface of the magnetic nanoparticles using a mixture of two surfactants, the magnetic fluid hyperthermia heating rate was significantly improved compared to using a single surfactant type. This improvement can be attributed to the larger effective anisotropy achieved through the modification with both (oleic acid/oleylamine). The mixture of surfactants enhances the control of interparticle distance and influences the strength of dipolar interactions, ultimately leading to enhanced heating efficiency. Functionalization of the oleic acid-coated nanoparticles with trimethoxysilane results in the formation of a core-shell structure Fe@Fe3O4, showing exchange bias (EB) associated with the exchange anisotropy between the shell and the core. The biomedical relevance of our synthesized Fe@Fe3O4 nanoparticles was demonstrated by their efficient uptake by human umbilical vein endothelial cells (HUVECs) in a concentration-dependent manner. This remarkable cellular uptake highlights the potential of these nanoparticles in biomedical applications.

Changes in IPCC Scenario Assessment Emulators Between SR1.5 and AR6 Unraveled.

The IPCC's scientific assessment of the timing of net-zero emissions and 2030 emission reduction targets consistent with limiting warming to 1.5°C or 2°C rests on large scenario databases. Updates to this assessment, such as between the IPCC's Special Report on Global Warming of 1.5°C (SR1.5) of warming and the Sixth Assessment Report (AR6), are the result of intertwined, sometimes opaque, factors. Here we isolate one factor: the Earth System Model emulators used to estimate the global warming implications of scenarios. We show that warming projections using AR6-calibrated emulators are consistent, to within around 0.1°C, with projections made by the emulators used in SR1.5. The consistency is due to two almost compensating changes: the increase in assessed historical warming between SR1.5 (based on AR5) and AR6, and a reduction in projected warming due to improved agreement between the emulators' response to emissions and the assessment to which it is calibrated.

Unique secondary metabolites of a Streptomyces strain isolated from extreme salty wetland show antioxidant and antibacterial activities.

AIMS: To identify and assess the biological activities of the crude extract of a Streptomyces isolate from a salty wetland, an extreme environment likely to induce secondary metabolism of micro-organisms. METHODS AND RESULTS: The crude extract from the isolate Streptomyces lanatus strain AR2 displayed antibacterial activity against Gram-positive bacteria (MICs ranging from 5 to 50 µg ml-1 ) and antioxidant activity as revealed in DPPH (2,2-diphenyl-1-picrylhydrazyl) assay (IC50 of 0·74 mg ml-1 ), ferric reducing antioxidant power (IC50 of 1·12 mg ml-1 ) and metal-chelating power (IC50 of 1·84 mg ml-1 ) assays. Accordingly, the extract attenuated the H2 O2 -induced oxidative stress in the eukaryotic cell model Saccharomyces cerevisiae, assessed by flow cytometry. The profiling of secondary metabolites by HPLC-PDA-ESI-MS/MS revealed the presence of 17 compounds, some of which reported in Streptomyces for the first time to the best of our knowledge: genistein-7-O-glucuronide, naringenin-7-O-rutinoside and resveratrol. CONCLUSIONS: Streptomyces lanatus AR2 produced unique polyketides and phenolic compounds with noticeable bioactivities, allowing adaptation to the extreme environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Sabkhat Seijoumi salty wetland represents a potential niche for Streptomyces yielding useful natural products for biotechnological, pharmaceutical and medical applications.

Exome sequencing revealed a novel deletion in the ERCC8 gene in an Iranian family with Cockayne syndrome.

Cockayne syndrome (CS) is one the rare DNA-repair deficiency disorders with autosomal recessive inheritance. Failure to thrive and microcephaly are the major criteria of diagnosis. Owing to genetic heterogeneity of CS, whole exome sequencing is promising way to determine the genetic basis of the disease. Here, we present c.1053delT in ERCC8 gene in an Iranian family with symptom of CS using whole exome sequencing. The deletion was novel and was not previously reported elsewhere.

Effect of temperature changes on the occurrence of congenital hypothyroidism.

OBJECTIVES: To investigate an association between seasonal changes in temperature and the prevalence of congenital hypothyroidism (CH) in the Southwest of Iran. METHODS: A prospective two-year study conducted from March 2007 to March 2009 during the nationwide screening programme for CH in Ahvaz, the biggest city in southwest Iran. Blood samples were taken from almost all newborns by heel-stick and used in a thyroid-stimulating hormone (TSH)-enzyme-linked immunosorbent assay (ELISA). Serum thyroxine (T4) and TSH were measured if the ELISA-TSH was >5 mIU/L (suspicious cases). Infants were considered to have CH with T4 <6.0 µg/dL and TSH > 10 mIU/L, or with normal T4 values and persistent high TSH values for >2 months (subclinical hypothyroidism). Date of birth and sex were recorded. Detailed temperature data were obtained from the meteorological organization. The relationship between the monthly incidence of CH and the average monthly temperature was investigated. RESULTS: From 47,075 (50.92% male) newborns, 1131 were referred (recall rate = 2.4%) and 142 infants (51.4% male) were confirmed to have CH. The seasonal distribution of CH cases was 32.4% in the warm period and 67.6% in the cold period of the year (19%, 13.4%, 32.4% and 35.2% in spring, summer, fall and winter, respectively; P = 0.001). A statistical difference was seen between mid-summer (2.8%, warmest time) and early winter (15.5%, coldest time). The above-mentioned difference was the same for suspicious individuals (P < 0.001). The odds of being affected were increased by 4% for each fall of 1°C. CONCLUSION: The prevalence of CH has a significant negative correlation with the temperature in the tropical area of Iran.

Temperature increase of 21st century mitigation scenarios.

Estimates of 21st Century global-mean surface temperature increase have generally been based on scenarios that do not include climate policies. Newly developed multigas mitigation scenarios, based on a wide range of modeling approaches and socioeconomic assumptions, now allow the assessment of possible impacts of climate policies on projected warming ranges. This article assesses the atmospheric CO(2) concentrations, radiative forcing, and temperature increase for these new scenarios using two reduced-complexity climate models. These scenarios result in temperature increase of 0.5-4.4 degrees C over 1990 levels or 0.3-3.4 degrees C less than the no-policy cases. The range results from differences in the assumed stringency of climate policy and uncertainty in our understanding of the climate system. Notably, an average minimum warming of approximately 1.4 degrees C (with a full range of 0.5-2.8 degrees C) remains for even the most stringent stabilization scenarios analyzed here. This value is substantially above previously estimated committed warming based on climate system inertia alone. The results show that, although ambitious mitigation efforts can significantly reduce global warming, adaptation measures will be needed in addition to mitigation to reduce the impact of the residual warming.

Kyste amygdaloide oropharynge : a propos d'un cas

Le kyste amygdaloide est une tumeur kystique latero-cervicale haute rare; issue de la 2eme fente branchiale. Il represente 2 des tumeurs latero-cervicales du cou; et 6;1a 85;2 des anomalies de la deuxieme fente. La forme oropharyngee est tres rare. Nous rapportons une observation d'un kyste amygdaloide oropharynge; chez une femme de 56 ans. Aucune symptomatologie particuliere n'a ete notee. L'examen clinique a revele une tumefaction de la loge amygdalienne droite; refoulant le pilier anterieur. La TDM a objective un processus expansif necrose de l'amygdale palatine droite comblant l'espace parapharynge droit; en contact avec la base de la langue et le muscle pterygoidien medial homolateral. Une resection complete et sans rupture du kyste a ete pratiquee par voie transorale; le geste a ete complete par une amyg- dalectomie droite. L'histologie a confirme le diagnostic par la co-existence d'un revetement epithelial et d'une infiltration de tissu lymphoide. Le recul est de 6 mois sans recidive

Evaluation et prise en charge de l'envahissement mandibulaire dans les carcinomes epidermoides de la cavite orale et de l'oropharynx

Objectif : Le but de notre etude est l'evaluation de l'atteinte mandibulaire dans les carcinomes epidermoides de la cavite orale et de l'oropharynx. Materiel et methodes : Il s'agit d'une etude retrospective a propos de 34 patients colliges sur 6 ans (1999-2004) et ayantun carcinome epidermoide de la cavite orale et/ou de l'oropharynx avec envahisse- ment mandibulaire confirme a l'anatomopathologie.L'atteinte mandibulaire a ete evaluee par l'examen clinique; l'orthopantomographie; la tomodensitometrie; et par les constata- tions peroperatoires du chirurgien. Tous les patients ont eu un evidement ganglionnaire; une exerese tumorale associee a une mandibulectomie segmentaire interruptrice ou conservatrice. Resultats : L'envahissement mandibulaire a ete suspecte cliniquement chez 70;5des patients devant l'adherence de la tumeur a l'os. Apres examen clinique et imagerie; cette atteinte a ete diagnostiquee chez 88;2des patients. Dans 11;8des cas; l'atteinte n'a ete suspectee qu'en peroperatoire. L'examen histologique a confirme l'atteinte osseuse chez tous les patients. La mandibulectomie segmentaire a ete pratiquee chez 17 patients devant l'atteinte du canal mandibulaire. Vingt-huit patients ont eu une radiotherapie postoperatoire a la dose moyenne de 64 Gy. Les taux de recidive; de metastase et de deces etaient respectivement de 11;7; 17;6et 17;6pour les patients qui ont eu une mandibulectomie segmentaire; et de 23;5; 17;6et 23;5pour ceux qui ont eu une mandibulectomie conservatrice. Par ailleurs; 76;5et 29;5 des patients ayant eu respectivement une mandibulectomie segmentaire et une mandibulectomie conservatrice avaient une gene fonctionnelle importante lors de l'alimentation.Conclusion : L'examen clinique; l'imagerie et l'examen peroperatoire sont d'un apport capital dans l'evaluation de l'atteinte mandibulaire. Une atteinte epargnant le canal mandibulaire justifie une mandibulectomie conservatrice permettant d'avoir de meilleurs resultats esthetiques et fonctionnels tout en assurant un controle carcinologiquement satisfaisant