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Article Citation - WoS: 1Citation - Scopus: 2Chemical Mechanical Polishing as an Alternative Surface Treatment Technique for Corrosion Prevention of Carbon Steel in an Acidic Medium(Nature Portfolio, 2025) Ahmed, Mohamed; Ali Al-Timimi, Buthainah; Al-Ali, Maha; Abdullah, Ghassan H.; Khalaf Atiyaha, Safa; Yaseen Ali Aljanabi, Ahmed; Mel, MaizirwanChemical mechanical polishing (CMP) has been a standard technique in semiconductor manufacturing for achieving smooth surfaces. CMP utilizes a synergistic interplay of chemical and mechanical interactions to achieve the desired removal rates, selectivity, and ultimately planarity with different substrate materials. In this study, the impact of CMP on the surface properties of steel used in the petroleum industry was examined, with a focus on its corrosion behavior posttreatment. Steel samples were subjected to CMP with and without an oxidizer in a silica-based slurry, and their surface characteristics were compared to those of samples polished mechanically. The addition of an oxidizer to the slurry resulted in increased material removal rates and the formation of an oxide layer on the surface; this phenomenon was not observed in CMP without an oxidizer. However, in mechanical polishing, the action of silicon carbide grains on the steel surface led to an increase in the removal rate but caused a decrease in its corrosion resistance. Compared with other treatments, the oxide layer provided a good protective barrier against corrosion and improved the corrosion resistance of the steel substrate. Based on the results from the practical study, an improvement in the corrosion resistance properties was observed due to the chemical reaction of the oxidizer and the mechanical action of the silica nanoparticles; these results showed the importance of chemical mechanical polishing as an alternative method to reduce the corrosion of steel in acidic environments. Additionally, the effect of hydrogen peroxide in a silica slurry with respect to the wettability, surface roughness, and hardness of steel was examined using contact angle measurements, profilometry, scanning electron microscopy, and microhardness tests.Article Protective Role of Bromelain’s Antioxidant and Anti-Inflammatory Effects in Experimental Lower Limb Ischemia-Reperfusion Injury(Nature Portfolio, 2025) Sezen, Saban Cem; Demirtas, Huseyin; Yildirim, Alperen Kutay; Ozer, Abdullah; Dursun, Ali Dogan; Kucuk, Aysegul; Arslan, Mustafa; Ozalp, Veli Cengiz; Kucuk, Işın GunesIschemia-reperfusion (IR) injury is a multifaceted pathological process characterized by excessive oxidative stress and inflammatory responses upon restoration of blood flow. Bromelain, a proteolytic enzyme complex derived from pineapple, exhibits robust antioxidant and anti-inflammatory activities. This study aimed to evaluate the protective effects and underlying mechanisms of bromelain on oxidative stress and inflammation in an experimental rat model of lower limb ischemia-reperfusion injury. Twenty-four male Wistar Albino rats were randomly allocated into four groups: Sham-operated control (SHAM), Bromelain-only (BR), Ischemia-Reperfusion (IR), and Ischemia-Reperfusion with Bromelain treatment (IR + BR). Bromelain (40 mg/kg) was administered intraperitoneally before ischemia induction. The IR model involved 45 min of infrarenal abdominal aorta occlusion followed by 120 min of reperfusion. Oxidative biomarkers (total antioxidant status [TAS], total oxidant status [TOS], oxidative stress index [OSI]) and histopathological parameters (muscle atrophy, degeneration, leukocyte infiltration, internalization of nuclei, fragmentation, and hyalinization) were analyzed. Significant increases in muscle degeneration, leukocyte infiltration, nuclear internalization, fragmentation, and elevated oxidative stress biomarkers (increased TOS and OSI, decreased TAS) were observed in the IR group compared to controls. Bromelain treatment (IR + BR) significantly ameliorated these effects, reducing muscle tissue damage, inflammation, and oxidative imbalance compared to the untreated IR group. Bromelain effectively mitigates lower limb ischemia-reperfusion injury by reducing oxidative stress, restoring antioxidant capacity, and suppressing inflammatory responses. These protective effects suggest that bromelain holds potential as a therapeutic agent for managing oxidative and inflammatory damages associated with IR conditions, warranting further clinical investigation.Article Citation - WoS: 344Citation - Scopus: 356A New Artificial Urine Protocol To Better Imitate Human Urine(Nature Portfolio, 2019) Sarigul, Neslihan; Korkmaz, Filiz; Kurultak, IlhanArtificial urine has many advantages over human urine for research and educational purposes. By closely mimicking healthy individuals' urine, it may also be important in discovering novel biomarkers. However, up until now, there has not been any specific protocol to prove the similarity in terms of the chemical composition at the molecular level. In this study, a new artificial urine protocol is established to mimics the urine of healthy individuals. The multi-purpose artificial urine (MP-AU) presented here is compared with two other protocols most cited in literature. Furthermore, these three protocols are also compared with samples from 28 healthy young individuals. To do so, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is used, according to which MP-AU shows a significantly close similarity with human urine. In formulating MP-AU, the infrared spectra of nine compounds is provided, making possible the band assignment of some absorption bands to certain compounds. Given its properties, the MP-AU protocol introduced here is both economical and practical, making it useful when designing comparative-controlled experiments.Correction A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic (vol 5, pg 1089, 2021)(Nature Portfolio, 2022) Wang, Ke; Goldenberg, Amit; Dorison, Charles A.; Miller, Jeremy K.; Uusberg, Andero; Lerner, Jennifer S.; Moshontz, Hannah[No Abstract Available]Article Citation - WoS: 9Citation - Scopus: 10Strain Engineering of Germanium Nanobeams by Electrostatic Actuation(Nature Portfolio, 2019) Ayan, Arman; Turkay, Deniz; Unlu, Buse; Naghinazhadahmadi, Parisa; Oliaei, Samad Nadimi Bavil; Boztug, Cicek; Yerci, SelcukGermanium (Ge) is a promising material for the development of a light source compatible with the silicon microfabrication technology, even though it is an indirect-bandgap material in its bulk form. Among various techniques suggested to boost the light emission efficiency of Ge, the strain induction is capable of providing the wavelength tunability if the strain is applied via an external force. Here, we introduce a method to control the amount of the axial strain, and therefore the emission wavelength, on a suspended Ge nanobeam by an applied voltage. We demonstrate, based on mechanical and electrical simulations, that axial strains over 4% can be achieved without experiencing any mechanical and/or electrical failure. We also show that the non-uniform strain distribution on the Ge nanobeam as a result of the applied voltage enhances light emission over 6 folds as compared to a Ge nanobeam with a uniform strain distribution. We anticipate that electrostatic actuation of Ge nanobeams provides a suitable platform for the realization of the on-chip tunable-wavelength infrared light sources that can be monolithically integrated on Si chips.Article Citation - WoS: 27Citation - Scopus: 28Microbial Community of Soda Lake Van as Obtained From Direct and Enriched Water, Sediment and Fish Samples(Nature Portfolio, 2021) Omeroglu, Esra Ersoy; Sudagidan, Mert; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Ozalp, Veli CengizSoda lakes are saline and alkaline ecosystems that are considered to have existed since the first geological records of the world. These lakes support the growth of ecologically and economically important microorganisms due to their unique geochemistry. Microbiota members of lakes are valuable models to study the link between community structure and abiotic parameters such as pH and salinity. Lake Van is the largest endroheic lake and in this study, bacterial diversity of lake water, sediment, and pearl mullet (inci kefali; Alburnus tarichi), an endemic species of fish which are collected from different points of the lake, are studied directly and investigated meticulously using a metabarcoding approach after pre-enrichment. Bacterial community structures were identified using Next Generation Sequencing of the 16S rRNA gene. The analysis revealed that the samples of Lake Van contain high level of bacterial diversity. Direct water samples were dominated by Proteobacteria, Cyanobacteria, and Bacteroidota, on the other hand, pre-enriched water samples were dominated by Proteobacteria and Firmicutes at phylum-level. In direct sediment samples Proteobacteria, whereas in pre-enriched sediment samples Firmicutes and Proteobacteria were determined at highest level. Pre-enriched fish samples were dominated by Proteobacteria and Firmicutes at phylum-level. In this study, microbiota members of Lake Van were identified by taxonomic analysis.Data Paper Citation - WoS: 2Citation - Scopus: 2The Psychological Science Accelerator's Covid-19 Rapid-Response Dataset(Nature Portfolio, 2023) Buchanan, Erin M.; Lewis, Savannah C.; Paris, Bastien; Forscher, Patrick S.; Pavlacic, Jeffrey M.; Beshears, Julie E.; Primbs, Maximilian A.In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data.Article Citation - WoS: 23Citation - Scopus: 26Mesenchymal Stem Cells Promote Spermatogonial Stem/Progenitor Cell Pool and Spermatogenesis in Neonatal Mice in Vitro(Nature Portfolio, 2022) Onen, Selin; Kose, Sevil; Yersal, Nilgun; Korkusuz, PetekPrepubertal cancer treatment leads to irreversible infertility in half of the male patients. Current in vitro spermatogenesis protocols and cryopreservation techniques are inadequate to expand spermatogonial stem/progenitor cells (SSPC) from testicles. Bone marrow derived mesenchymal stem cells (BM-MSC) bearing a close resemblance to Sertoli cells, improved spermatogenesis in animal models. We asked if a co-culture setup supported by syngeneic BM-MSC that contributes to the air-liquid interphase (ALI) could lead to survival, expansion and differentiation of SSPCs in vitro. We generated an ALI platform able to provide a real-time cellular paracrine contribution consisting of syngeneic BM-MSCs to neonatal C57BL/6 mice testes. We aimed to evaluate the efficacy of this culture system on SSPC pool expansion and spermatogenesis throughout a complete spermatogenic cycle by measuring the number of total germ cells (GC), the undifferentiated and differentiating spermatogonia, the spermatocytes and the spermatids. Furthermore, we evaluated the testicular cell cycle phases, the tubular and luminal areas using histochemical, immunohistochemical and flow cytometric techniques. Cultures in present of BM-MSCs displayed survival of ID4(+) spermatogonial stem cells (SSC), expansion of SALL4(+) and OCT4(+) SSPCs, VASA(+) total GCs and Ki67(+) proliferative cells at 42 days and an increased number of SCP3(+) spermatocytes and Acrosin(+) spermatids at 28 days. BM-MSCs increased the percentage of mitotic cells within the G2-M phase of the total testicular cell cycle increased for 7 days, preserved the cell viability for 42 days and induced testicular maturation by enlargement of the tubular and luminal area for 42 days in comparison to the control. The percentage of PLZF(+) SSPCs increased within the first 28 days of culture, after which the pool started to get smaller while the number of spermatocytes and spermatids increased simultaneously. Our findings established the efficacy of syngeneic BM-MSCs on the survival and expansion of the SSPC pool and differentiation of spermatogonia to round spermatids during in vitro culture of prepubertal mice testes for 42 days. This method may be helpful in providing alternative cures for male fertility by supporting in vitro differentiated spermatids that can be used for round spermatid injection (ROSI) to female oocyte in animal models. These findings can be further exploited for personalized cellular therapy strategies to cure male infertility of prepubertal cancer survivors in clinics.Article Citation - WoS: 4Citation - Scopus: 5Antioxidant Activity of Micractinium Sp. (Chlorophyta) Extracts Against H2O2 Induced Oxidative Stress in Human Breast Adenocarcinoma Cells(Nature Portfolio, 2024) Bulut, Onur; Kose, Iskin Engin; Sonmez, Cagla; Oktem, Huseyin AvniIn response to the growing demand for high-value bioactive compounds, microalgae cultivation has gained a significant acceleration in recent years. Among these compounds, antioxidants have emerged as essential constituents in the food, pharmaceutical, and cosmetics industries. This study focuses on Micractinium sp. ME05, a green microalgal strain previously isolated from hot springs flora in our laboratory. Micractinium sp. cells were extracted using six different solvents, and their antioxidant capacity, as well as total phenolic, flavonoid, and carotenoid contents were evaluated. The methanolic extracts demonstrated the highest antioxidant capacity, measuring 7.72 and 93.80 mu mol trolox equivalents g-1 dry weight (DW) according to the DPPH and FRAP assays, respectively. To further characterize the biochemical profile, reverse phase high-performance chromatography (RP-HPLC) was employed to quantify twelve different phenolics, including rutin, gallic acid, benzoic acid, cinnamic acid, and beta-carotene, in the microalgal extracts. Notably, the acetone extracts of Micractinium sp. grown mixotrophically contained a high amount of gallic acid (469.21 +/- 159.74 mu g g-1 DW), while 4-hydroxy benzoic acid (403.93 +/- 20.98 mu g g-1 DW) was the main phenolic compound in the methanolic extracts under heterotrophic cultivation. Moreover, extracts from Micractinium sp. exhibited remarkable cytoprotective activity by effectively inhibiting hydrogen peroxide-induced oxidative stress and cell death in human breast adenocarcinoma (MCF-7) cells. In conclusion, with its diverse biochemical composition and adaptability to different growth regimens, Micractinium sp. emerges as a robust candidate for mass cultivation in nutraceutical and food applications.Article ACPA Prevents Lung Fibroblast-to Transformation by Reprogramming the Tumor Microenvironment through NSCLC-Derived Exosomes(Nature Portfolio, 2025) Boyacioglu, Ozge; Kalali, Berfin Deniz; Recber, Tuba; Gelen-Gungor, Dilek; Nemutlu, Emirhan; Eroglu, Ipek; Korkusuz, Petek; Kilic, NedretNon-small cell lung cancer (NSCLC) accounts for most lung cancer cases. Current treatments often cause systemic side effects or lead to drug resistance, prompting the development of new therapies targeting tumors and related cells simultaneously. Cancer-associated fibroblasts (CAFs) are crucial stromal cells within the tumor microenvironment (TME), making them potential targets for therapy. Previously, we found that the CB1 receptor agonist ACPA has anti-tumor effects on NSCLC, inhibiting pathways such as Akt/PI3K, JNK, glycolysis, the citric acid cycle, and the urea cycle both in vitro and in vivo. We hypothesize that ACPA could enhance therapy by inhibiting the transformation of lung fibroblasts into CAFs via exosomes. Control and ACPA-treated NSCLC cell exosomes exhibited similar size, PDI, ZP, and high expression of CD9, CD63, and CD81. ACPA-treated exosomes showed reduced levels of miR-21 and miR-23. These exosomes decreased fibroblast viability within 12 h by disrupting pentose phosphate, lipid, and amino acid metabolism, and by lowering PDPN, alpha-SMA, and FAP expressions. This research highlights ACPA as a promising chemotherapeutic agent, capable of improving NSCLC treatment and reprogramming the TME with more targeted therapies.
