stoRNA: Stateless Transparent Proofs of Storage-time

Proof of Storage-time (PoSt) is a cryptographic primitive that enables a server to demonstrate non-interactive continuous avail- ability of outsourced data in a publicly verifiable way. This notion was first introduced by Filecoin to secure their Blockchain-based decentral- ized storage marketplace, using expensive SNARKs to compact proofs. Recent work [2] employs the notion of trapdoor delay function to address the problem of compact PoSt without SNARKs. This approach however entails statefulness and non-transparency, while it requires an expensive pre-processing phase by the client. All of the above renders their solution impractical for decentralized storage marketplaces, leaving the stateless trapdoor-free PoSt with reduced setup costs as an open problem. In this work, we present stateless and transparent PoSt constructions using probabilistic sampling and a new Merkle variant commitment. In the process of enabling adjustable prover difficulty, we then propose a multi- prover construction to diminish the CPU work each prover is required to do. Both schemes feature a fast setup phase and logarithmic verification time and bandwidth with the end-to-end setup, prove, and verification costs lower than the existing solution

Facile protocol, metal-free, one-pot synthesis of 2-amino-4H-chromenes, benzimidazoles, and benzothiazoles via acidic ionic liquids based on pyridinium

In a one-pot tandem condensation reaction, three functional ionic liquids (ILs) derived from pyridinium were employed as green, reusable, and efficient catalysts for the synthesis of important medicinal chemistry derivatives such as 2-amino-4H-chromenes. Additionally, benzimidazoles and benzothiazoles were synthesized using these catalysts. The ILs were favored for their easy set-up, high yields, and short synthesis times for the desired products. Moreover, the ILs could be easily recovered and reuse multiple times without significant loss of catalytic activity. Characterization of the synthesized compound was achieved through FT-IR, 1H NMR, 13C NMR, TGA and melting point analysis. The compounds were prepared with good to excellent isolated yields under mild conditions, while the synthesis of benzimidazoles and benzothiazole derivatives was successful at both reflux and room temperature conditions. Finally, each class of compound was described along with its corresponding synthesis mechanism

The evaluation of physical properties of a polyurethane expandable endodontic sealer: a preliminary study

Endodontic sealers play a vital role in providing 3-dimensional (3D) filling of complex root canal system (RCS). This study intended to compare the physical properties of a Polyurethane Expandable Sealer (PES), AH Plus and EndoSequence. Three properties including setting time, radiopacity and flow (rheology) were evaluated based on ISO 6876 standard. For evaluation of each of these physical properties, five samples from experimental groups: AH Plus, EndoSequence, PES (controlled expansion) and PES (high expansion) were used (n = 5). Data were analysed by one-way ANOVA and Post Hoc Tukey tests (a = 0.05). EndoSequence showed the longest setting time (P \u3c 0.000); AH Plus showed that highest radiopacity (P \u3c 0.000); and PES (high expansion) showed the highest flow (diameter and surface area) (P \u3c 0.000). EndoSequence and PES (controlled expansion) showed promising and comparable physical properties to the AH Plus sealer in terms of flow, setting time and radiopacity

Histopathological and biomedical parameters determination in the protective effect of crocin on hepatotoxicity induced by methotrexate in rats

Introduction: Methotrexate (Met) as a chemotherapy drug has many side effects, such as infiltration of neutrophils and the development of oxidative stress. Crocin (Cro), a carotenoid isolated from saffron, has numerous therapeutic characteristics including anticancer and antioxidant activities. This study was designed to evaluate the effects of Cro against hepatic damage in rats induced by Met. Methods: In this study, 48 male Wistar rats were randomly assigned into 8 groups, control normal (saline), Met control-treated group (20 mg/kg), Cro groups (12.5, 25, 50 mg/kg) and Met + Cro treated groups (12.5, 25, 50 mg/kg). Treatments were administered by intraperitoneal injection daily for 28 days. Griess technique was hired for the determination of serum nitrite oxide (NO) level. Concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were determined in order to assess liver function disturbances. In addition, Thiobarbituric acid reactive species, antioxidant capacity, the diameter of hepatocytes and central hepatic vein (CHV) were investigated. Results: Met administration significantly increased the liver malondialdehyde (MDA) and NO level, the mean diameter of CHV, hepatocytes and hepatic enzymes. Met also decreased the tissue FRAP level compared to the normal control group (P < 0.01). The Cro and Cro + Met treatments in all doses significantly reduced the mean diameter of hepatocytes and CHV, hepatic enzymes, hepatic MDA and NO levels and increased the tissue FRAP level compared to the Met control group (P < 0.01). Conclusion: It seems that the Cro administration improves liver injury induced by Met in rats

Effects of gallic acid on rat testopathy following morphine administration: an experimental study

Introduction: Morphine (MOR) as a psychoactive agent in the opium family causes free radicals accumulation which leads to failure in spermatogenesis. Gallic acid (GA), a polyphenolic acid, is found in various plants with antioxidant, anti-fungal, anti-viral, and anti-allergic activities. The purpose of this study was to evaluate the effects of GA against MOR-induced damage to the reproductive parameter of rats. Methods: Sixty-four male Wistar rats (8 weeks, 220-250 g) were categorized into 8 groups by random (n=8/each); normal control and MOR control groups; GA groups (5, 10, 20 mg/kg) and MOR + GA groups (5, 10, 20 mg/kg). Treatments were administered intraperitoneally (i.p), daily for 4 weeks. The sperm parameters, spermatogenesis index (SI), total antioxidant capacity, testosterone level, and seminiferous tube diameter (STD) were assessed. Results: All sperm parameters reduced significantly in the MOR control group than to the normal control group (P < 0.01). All parameters were significantly improved in GA and GA + MOR treatment groups compared to the MOR control group (P < 0.01). Conclusion: MOR caused a detrimental effect on male reproductive parameters. Also, no significant modifications were observed in all doses of GA treatments in comparison with the normal control group. GA compensates the toxic effect of MOR on reproductive parameters. Hence, GA administration is beneficial in MOR users

Serum Levels of Thyroid Hormones and Vitamin D in Women with Melasma

Background and purpose: Melasma is a common skin pigmentation disorder that manifests as hyperpigmented macules and patches. Genetic predisposition, sun exposure, and pregnancy are known risk factors for melasma. Previous studies have suggested that thyroid disorders may be associated with melasma. Given the fact that vitamin D affects and stimulates the production of melanin by melanocytes, this study aimed to investigate the relationship between thyroid disorders and serum level of vitamin D with melasma in female patients attending Qaemshahr Razi Hospital and Sari Bouali-Sina Hospital. Materials and methods: In this study, 80 people were divided into melasma group (n=40) and control group (n=40). They were matched for sex and age. Serum levels of TSH, Anti-TPO, T3, T4, and Vit D were measured in both groups. The standard mMASI score was used to measure the clinical severity of pigmentation in patients with melasma. Results: The prevalence of thyroid abnormalities and serum levels of vitamin D were seen in 50% and 47.5% of patients with melasma and 27.5% and 40% of the control group, respectively. Examination of thyroid hormone and vitamin D levels showed that T3 level was significantly higher in case group (P<0.05). Investigating the relationship between thyroid hormones, vitamin D and age with mMASI Score showed a relationship only between Anti-TPO and mMASI Score (P< 0.05). Conclusion: Thyroid autoimmune disorders are associated with melasma and severity of pigmentation. Centrofacial form of melasma is also the most common clinical form

Titanate nanotubes–incorporated poly(vinyl alcohol) mixed matrix membranes for pervaporation separation of water-isopropanol mixtures

Mixed matrix membranes (MMMs) base on poly(vinyl alcohol) (PVA) incorporated with titanate nanotubes (TNTs), cross-linked with glutaraldehyde, were prepared. The hydrothermally synthesized TNTs and the membranes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), Thermogravimetric analysis (TGA), Field emission scanning electron microscope (FESEM), and tensile strength analyses. The prepared nanocomposite membranes were used for dehydration of isopropanol by pervaporation process. The effects of the weight fraction of TNTs, feed temperature, and concentration on the performance of the membranes were investigated. The results indicated that incorporation of hydrophilic TNTs could effectively improve the separation performance of PVA membranes in terms of both permeability and separation factor. Based on the results, the separation factor of all nanocomposite membranes was increased. Moreover, the membrane containing 4 wt% of TNTs exhibited the highest separation factor value of 5520, while the maximum value of flux was about 0.126 kg/m 2 h for the membrane containing 10 wt% TNTs. So, there was about 794% and 741% enhancement in separation factor and flux respectively, compared to the pristine PVA membranes. Consequently, the results confirm incorporating TNTs in the PVA matrix could improve the separation of water from isopropanol aqueous solutions effectively due to the intrinsic hydrophilicity and special structure of TNTs. </p

Effects of addition of different probiotic strains on the biochemical and microbiological properties of Aloe vera drink

Introduction: Recently, an increased demand for nondairy probiotic products comes from the vegetarians, those with lactose intolerance and high cholesterol blood content in dairy products. In this research, the effects of adding different probiotic strains to the Aloe vera drink were studied on biochemical and microbiological specifics during refrigerated storage. Materials and Methods: About 7% of any cultured single strain probiotic (Lactobacillus (L) acidophilus, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus fermentumor Lactobacillus plantarum) were added to Aloe vera juices. Samples were studied in 7 days intervals throughout 21 days of storage at 5&deg;C. pH and redox potential values were measured by pH-meter. Titrable acidity value was determined by titration with 0.1 N NaOH. Probiotic bacteria were enumerated using MRS-agar medium. Results: The highest and lowest biochemical changes were observed in treatments with L. reuteri and L. acidophilus, respectively. Therefore, different types of inoculated probiotic strains, with different ability in fermentation at refrigerated temperature, had effects on the amount of the biochemical changes during storage. The most probiotic viable counts in treatments with L. acidophilus were observed at the end of storage. Conclusion: Probiotic viability was improved in Aloe vera juices probably due to high amounts of nutrients such as aminoacids, proteins, sugars, vitamins, phenolic compounds and antioxidants. L. acidophilus and L. fermentum are suitable choice to use in Aloe vera drin

Improvement of ethanol production from birch and spruce pretreated with 1-H-3-methylmorpholinium chloride

Background: Pretreatment is the critically important step for the production of ethanol from lignocelluloses. In this study, hardwood birch (Betula pendula) and softwood spruce (Norway spruce) woods were pretreated with a newly synthesized morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]), followed by enzymatic hydrolysis and fermentation to ethanol. Results: [HMMorph][Cl] was synthesized using inexpensive raw materials, i.e., hydrochloric acid and N-methyl morpholine, following a simple process. The influence of pretreatment time (2, 3, 5, and 8 h) and temperature (120 and 140°C) in terms of hydrolysis efficiency was investigated. Glucose yields from enzymatic hydrolysis were improved from 13.7% to 45.7% and 12.9% to 51.8% after pretreatment of birch and spruce woods, respectively, under optimum pretreatment conditions (i.e., at 140°C for 3 h) as compared to those from pristine woods. Moreover, the yields of ethanol production from birch and spruce were increased to 34.8% and 44.2%, respectively, while the yields were negligible for untreated woods. Conclusions: This study demonstrated the ability of [HMMorph][Cl] as an inexpensive agent to pretreat both softwood and hardwood.Bio4Energ

A morpholinium ionic liquid for rice straw pretreatment to enhance ethanol production

Rice straw was successfully pretreated with a novel and inexpensive morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]). The influence of water (30, 40, 50% w/w) and dimethyl sulfoxide (DMSO) (10, 30% w/w), as co-solvents, pretreatment time (2, 3, 5 h), temperature (90, 105, 120 \ub0C), solid loading (5, 6.7, 10% w/w), and straw particle size (&lt;0.177, 0.177–0.841 mm, and 0.841–2 mm) were investigated for maximum ethanol production. The best results were obtained in 50% water, at 120 \ub0C and 5% (w/w) solid loading for 5 h from 0.177 – 0.841 mm straw particles. The hydrolysis yield was increased from 33.2% to 70.1%, while ethanol production yield was improved from 21.9% to 64% of the theoretical maximum. The performance of the IL was comparable to 1-ethyl-3-methylimidazolium acetate. Simple synthesis process and dilute solution required for the pretreatment with [HMMorph][Cl] offers cost reductions in the use of ILs in biofuel production