One of the most important challenges researchers and managers confront in conservation ecology is predicting a population's response to sub-lethal stressors. Such predictions have been particularly ...elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970-2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.
Fisheries management relies on accurate population models for estimating biomass and setting harvest goals; however, physiological data for estimating reproductive parameters in population models are ...difficult to acquire. Here, lifetime reproductive (progesterone and estradiol) and stress-related (cortisol) hormones were measured in annually deposited growth increments in female yelloweye rockfish (Sebastes ruberrimus) opercula (N = 22 females, sampled ages 1-90 years). Analyses of these profiles (~1-year resolution) provided estimates of physiological (complete puberty) and functional age of sexual maturity (females spawn and contribute larvae to the population) and spawning frequency, with lifetime trends of reproduction and stress. The descriptive mean age of physiological sexual maturity was 11 + or - 1 years (standard error (SE)), whereas functional age of maturity was 17 + or - 2 years. The estimate of marginal mean spawning frequency was 45.1% + or - 5.1%. Stress data (~15% of females experienced distress events) suggested that females were potentially resilient or not exposed to chronic stressors. Although preliminary, we provide a novel method to estimate age-specific reproductive parameters for proper age-based population modeling of a human-targeted teleost.
Despite decades of effort, significant knowledge gaps still exist regarding the global transport and distribution of persistent organic pollutants (POPs) in marine ecosystems, especially for periods ...prior to the 1970s. Furthermore, for long-lived marine mammals such as baleen whales, POPs impacts on early developmental (first years of life), as well as lifetime exposure profiles for periods of use and phase-out, are not well characterized. Recently, analytical techniques capable of reconstructing lifetime (i.e., birth to death; ~6 mos. resolution) chemical exposure profiles in baleen whale earplugs have been developed. Earplugs represent a unique opportunity to examine the spatiotemporal trends of POPs in the marine ecosystem. Baleen whale earplugs were collected from six whales (one blue whale (Balaenoptera musculus) and five fin whales (Balaenoptera physalus)), including four from archived collections and two from recent strandings. Lifespans for some of these individuals date back to the 1930s and provide insight into early periods of POP use. POP concentrations (reported in ng g–1 dry wt.) were determined in laminae (n = 35) and were combined with age estimates and calendar year to reconstruct lifetime POP exposure profiles and lifetime bioaccumulation rates. Dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs) were found to be the most dominant POPs (spanning the past 80 y), were detected as early as the 1930s and were ubiquitous in the North Pacific and Atlantic Oceans. Lifetime bioaccumulation rates determined using baleen whale earplugs were 56 times higher in the North Pacific as compared to the North Atlantic. This suggest baleen whales from the North Pacific may be to be exposed to increased levels of POPs.
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•Reconstructed life-history of POP exposure using baleen whale earplugs.•POPs measured in marine mammals dating back to the 1930s.•Data suggest POP bioaccumulation rates higher in the North Pacific than Atlantic.•Exposure profiles were dominated by DDT, and its metabolites, and PCBs.
Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species and an integral ...part of the marine ecosystem. Increasing anthropogenic terrestrial and marine activities alter ocean systems, and such alterations could change foraging and feeding behavior of baleen whales. In this study, we analyzed δ13C and δ15N of baleen whale earplugs from three different species (N = 6 earplugs, n = 337 laminae) to reconstruct the first continuous stable isotope profiles with a six-month resolution. Results of our study provide an unprecedented opportunity to assess behavioral as well as ecological changes. Abrupt shifts and temporal variability observed in δ13C and δ15N profiles could be indicative of behavior change such as shift in foraging location and/or trophic level in response to natural or anthropogenic disturbances. Additionally, five out of six individuals demonstrated long-term declining trends in δ13C profiles, which could suggest influence of emission of depleted 13CO2 from fossil fuel combustion referred to as the Suess effect. After adjusting the δ13C values of earplugs for the estimated Suess effect and re-evaluating δ13C profiles, significant decline in δ13C values as well as different rate of depletion suggest contribution of other sources that could impact δ13C values at the base of the food web.
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•Reconstructed life-history δ13C and δ15N profiles in baleen whale•Evidence of the Suess effect in whale earplugs dating back to the 1930s•Life history behavior changes were observed in δ13C and δ15N profiles.•Long-term ecological change was identified using δ13C lifetime profiles.
Abstract
Marine animals experience additional stressors as humans continue to industrialize the oceans and as the climate continues to rapidly change. To examine how the environment or humans impact ...animal stress, many researchers analyse hormones from biological matrices. Scientists have begun to examine hormones in continuously growing biological matrices, such as baleen whale earwax plugs, baleen and pinniped vibrissae. Few of these studies have determined if the hormones in these tissues across the body of the organism are interchangeable. Here, hormone values in the right and left earplugs from the same individual were compared for two reasons: (i) to determine whether right and left earplug hormone values can be used interchangeably and (ii) to assess methods of standardizing hormones in right and left earplugs to control for individuals’ naturally varying hormone expressions. We analysed how absolute, baseline-corrected and Z-score normalized hormones performed in reaching these goals. Absolute hormones in the right and left earplugs displayed a positive relationship, while using Z-score normalization was necessary to standardize the variance in hormone expression. After Z-score normalization, it was possible to show that the 95% confidence intervals of the differences in corresponding lamina of the right and left earplugs include zero for both cortisol and progesterone. This indicates that the hormones in corresponding lamina of right and left earplugs are no different from zero. The results of this study reveal that both right and left earplugs from the same baleen whale can be used in hormone analyses after Z-score normalization. This study also shows the importance of Z-score normalization to interpretation of results and methodologies associated with analysing long-term trends using whale earplugs.
Interfering with interactions of vascular endothelial growth factors (VEGFs) with their receptors (VEGFRs) effectively inhibits angiogenesis and tumor growth. We designed an antagonist peptide of ...VEGF-A and VEGF-B reproducing two discontinuous receptor binding regions of VEGF-B (loop 1 and loop3) covalently linked together by a receptor binding region of VEGF-A (loop3). The designed peptide (referred to as VGB4) was able to bind to both VEGFR1 and VEGFR2 on the Human Umbilical Vein Endothelial Cells (HUVECs) surface and inhibited VEGF-A driven proliferation, migration and tube formation in HUVECs through suppression of ERK1/2 and AKT phosphorylation. The whole-animal fluorescence imaging demonstrated that fluorescein isothiocyanate (FITC)-VGB4 accumulated in the mammary carcinoma tumors (MCTs). Administration of VGB4 led to the regression of 4T1 murine MCT growth through decreased expression of p-VEGFR1 and p-VEGFR2 and abrogation of ERK1/2 and AKT activation followed by considerable decrease of tumor cell proliferation (Ki67 expression) and angiogenesis (CD31 and CD34 expression), induction of apoptosis (increased p53 expression, TUNEL staining and decreased Bcl2 expression), and suppression of metastasis (increased E-cadherin and decreased N-cadherin, NF-κB and MMP-9 expression). These findings indicate that VGB4 may be applicable for antiangiogenic and antitumor therapy.
•Role of chemical compounds (CHCs) on wettability alteration (WA) of carbonate (CB) rock and related challenges.•Systematic wettability alteration study by chemical compounds, Ionic liquids, ...Nanofluids, Smart water and low salinity.•Describing the mechanisms of wettability alteration (WA) by chemical compounds.•Economical challenges for chemical EOR methods are reported.•The potential research gap in the field of chemical EOR techniques are proposed.
Although significant efforts have been made in research areas related to Enhanced oil recovery (EOR) and the role of rock wettability alteration (WA) at reservoir conditions using chemicals, a comprehensive study of chemical EOR in terms of chemical classification is still a required. Generally, chemical compounds (CHCs) can contribute to further oil recovery in oil reservoirs through several mechanisms including interfacial tension (IFT) reduction and altering rock wettability mode. This paper was examined the effect of different types of CHCs on EOR processes and various core flooding processes to increase the oil recovery efficiency. In this regard, a large domain of research reports was extensively reviewed by an in-depth analysis of various chemicals. Besides the application and limitations of chemicals, the areas of conflict and contradictory observations were also discussed. Also, their critical situation is highlighted, and the most promising potential methods were known. Surfactants (SURFs) are known to increase the water wetness of rock surface which leads to the higher relative permeability of the oil phase. Besides, the wetting states of the reservoir, also determine how fluids are dispersed in the pore space. Nanofluids (NFs) improve oil reservoir efficiency through a variety of methods, including a reduction in contact angle (CA), which changes the wettability from oil-wet (OW) to water-wet (WW). Smart and low salinity (LS) waterflooding (WF) are regarded as the very low cost chemical flooding which is proposed for matured OW reservoirs, since it controls the salinity of injected water to improve oil recovery. Also, the field point of view about the economic feasibility of each type of chemical has been comprehensively discussed. The presented results could help the researchers to select the best CHC for EOR tests and minimizing any damage because of incompatibities. Since the oil recovery mechanisms are more complex in carbonate (CB) reservoirs, this manuscript gocus more on CB formation and the results for CHC injection are well tabulated for different reasons.
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•Synthesis of Zn(LXSN)2 from disulfide Schiff bases L1-L3 in the presence of PPh3.•L1-L3 undergo reductive SS bond cleavage and form zinc(II) thiolate complexes 1–3.•X-ray crystal ...structures of the L1 and pseudotetrahedral 1–3 have been determined.•The binding of 1–3 toward DNA and BSA has been confirmed by different analyses.•1–3 exhibit effective cytotoxicity against HeLa and MCF-7 cell lines, comparable to cisplatin.
The synthesis of three potentially tetradentate, N2S2 Schiff-base-ligands, containing a disulfide bond, LThioSSLThio(L1), LBrSSLBr (L2) and LDiMeOSSLDiMeO (L3) are reported. These ligands undergo reductive disulfide bond scission upon reaction with PPh3 in the presence of Zn2+ ion. LDiOMeS−, LThioS− and LBrS− are the resulting bidentate thiolate-imine anions respectively, which upon reaction with Zn2+ produce three new zinc(II) complexes: Zn(LThioSN)2 (1), Zn(LBrSN)2 (2) and Zn(LDiOMeSN)2 (3). The structures of (L1) and 1–3 complexes were determined by X-ray diffraction. The interaction of 1–3 with CT-DNA have been investigated by absorption, emission, and CD spectroscopic methods and thermal denaturation measurements. The resulting data reveal that 1–3 show effective binding to CT-DNA (Kb = 2.2 × 104 to 1 × 105 L mol−1). The binding mode of DNA with 1–3 has also been investigated by molecular docking. The protein binding ability of 1–3 has been tested by monitoring the tryptophan emission intensity using BSA as a model protein. The quenching mechanism of BSA by the zinc complexes is static (kq = 1.66 to 3.4 × 1013 L mol−1 s−1). It is remarkable that 1–3 exhibit effective cytotoxicity against two human tumour cell lines (HeLa and MCF-7). The potent cytotoxic effects of 2 and 3, with IC50 values of 19.93 and 20.11 respectively, are higher relative to clinically used cisplatin (IC50 = 23.50) against the MCF-7 cell line, indicating that 2 and 3 may have the potential to act as effective metal-based anticancer drugs.
•An SPR based DNA biosensor has been developed for detection of donkey meat marker.•Gold nanostars was used as enhanced label in the sandwich hybridization assay.•Target DNA could be detected with ...the LLOQ of 1.0 nM and RSD of 0.85%.•The detection of 1% and 5% values of donkey meat adulteration was successfully done.
Herein, a surface plasmon resonance (SPR) enhanced DNA biosensor has been developed for real-time detection of donkey meat marker using biotinylated reporter and streptavidin functionalized gold nanostars (Stre@GNSs). Compared to the direct detection assay, this sandwich format for the enhancement of the signal, resulted in 6-folds orders increase in the sensitivity. Target DNA could be detected with the lower limit of quantification (LLOQ) of 1.0 nM with a relative standard deviation (RSD, n = 3) of 0.85%. In addition, the fabricated SPR sensor showed good selectivity for the target analyte over full complementary, single-base mismatch, three base-mismatch and non-complementary oligonucleotides. Finally, the proposed sensor was successfully applied for detection of donkey meat adulteration with various percentages in homemade beef sausage, as a real sample. The results indicated that the proposed biosensor provides a high specificity, easy, good sensitivity and fast approach for identification of donkey meat adulteration in food samples.
Chemotherapy is the most common treatment strategy for cancer patients. Nevertheless, limited drug delivery to cancer cells, intolerable toxicity, and multiple drug resistance are constant challenges ...of chemotherapy. Novel targeted drug delivery strategies by using nanoparticles have attracted much attention due to reducing side effects and increasing drug efficacy. Therefore, the most important outcome of this study is to answer the question of whether active targeted HA-based drug nanocarriers have a significant effect on improving drug delivery to cancer cells.
This study aimed to systematically review studies on the use of hyaluronic acid (HA)-based nanocarriers for chemotherapy drugs. The two databases MagIran and SID from Persian databases as well as international databases PubMed, WoS, Scopus, Science Direct, Embase, as well as Google Scholar were searched for human studies and cell lines and/or xenograft mice published without time limit until 2020. Keywords used to search included Nanoparticle, chemotherapy, HA, Hyaluronic acid, traditional medicine, natural medicine, chemotherapeutic drugs, natural compound, cancer treatment, and cancer. The quality of the studies was assessed by the STROBE checklist. Finally, studies consistent with inclusion criteria and with medium- to high-quality were included in the systematic review.
According to the findings of studies, active targeted HA-based drug nanocarriers showed a significant effect on improving drug delivery to cancer cells. Also, the use of lipid nanoparticles with a suitable coating of HA have been introduced as biocompatible drug carriers with high potential for targeted drug delivery to the target tissue without affecting other tissues and reducing side effects. Enhanced drug delivery, increased therapeutic efficacy, increased cytotoxicity and significant inhibition of tumor growth, as well as high potential for targeted chemotherapy are also reported to be benefits of using HA-based nanocarriers for tumors with increased expression of CD44 receptor.
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