1,633 research outputs found

    Exploration of microalgal culture using a semi-closed thin layer cascade photobioreactor for biodiesel synthesis and protein production

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    The expanding aquaculture industry increases the prices of fishmeal, the main protein source in fish diet. A promising alternative is microalgal protein. Therefore, the protein production capacities of two green microalgae species, Chlorella sorokiniana CY1 and Chlorella vulgaris ESP-31, were investigated. After optimization, the maximum biomass and protein productivities of Chlorella sorokiniana CY1 reached high values of 4.35 ± 0.09 and 0.856 ± 0.025 g/L/d, while that of Chlorella vulgaris ESP-31 also reached high values of 4.636 ± 0.10 and 0.946 ± 0.065 g/L/d. The cultivation time for both species was only 2 days, wherein Chlorella sorokiniana CY1 and Chlorella vulgaris ESP-31 amassed moderate protein contents of 25.9 ± 1.3% and 26.8 ± 1.3%. The optimum conditions for both species were 50% initial nitrate concentration of Basal medium, 5% CO2 aeration, and 750 µmol/m2/s light intensity. The high biomass and protein productivities of both species indicated their capability as potential protein sources. After studying protein production from microalgae, a second microalgae-derived commodity that received global attention was microalgal biofuels, in particular biodiesel. Microalgae is widely regarded as the most promising source of green and sustainable fuel for the future, with microalgal biodiesel widely seen as a replacement for diesel fuel. Compared to biodiesel from terrestrial crops such as palm oil and rapeseed, the benefits of microalgal biodiesel include rapid growth rate of microalgal cells, higher carbohydrate and lipid content, higher productivity per unit land area, and utilisation of wastewater for growth. Therefore, five indigenous microalgae species from Taiwan were selected to determine their potential for lipid production, namely Chlamydomonas sp. Tai-01, Tai-03 and Pin-01, as well as Scenedesmus sp. ESP-05 and ESP-07. Chlamydomonas sp. Tai-03 proved to be the best strain, achieving biomass growth and productivity of 3.48 ± 0.04 g/L and 0.43 ± 0.01 g/L/d, accompanied by an oil content and oil productivity of 28.6 ± 1.41% and 124.1 ± 7.57 mg/L/d. This was attained by inoculating 0.12 g/L biomass into BG-11 medium with 25% initial nitrate concentration and light-emitting diode (LED) light intensity of 200 µmol/m2/s. The fatty acid methyl esters (FAMEs) obtained from the Chlamydomonas sp. Tai-03 strain consisted mainly of palmitic acid, oleic acid and linoleic acid, making this microalga a suitable feedstock for biodiesel synthesis. The microalga species Chlamydomonas sp. Tai-03, which was previously optimised for maximal lipid production for biodiesel generation, received further optimization by investigating the effects of different CO2 concentration and different medium replacement strategy using semi-batch operation. The optimum conditions were found as 5% CO2 concentration and semi-batch operation with 25% medium replacement ratio, which further enhanced the biomass growth and productivity to 4.15 ± 0.12 g/L and 1.23 ± 0.02 g/L/d, with lipid content and productivity of 19.4 ± 2.0% and 239.6 ± 24.8 mg/L/d. Under the medium replacement strategy, 25% of the microalgal biomass could be replaced/harvested daily after the culture entered the medium replacement phase of the cultivation process (which was 8 days after the start of cultivation). Upon analysis, the major fatty acid methyl esters (FAMEs) were palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2). These short-chain FAMEs combined with high growth rate make Chlamydomonas sp. Tai-03 a suitable candidate for biodiesel synthesis. Although microalgae can be turned into numerous valuable commodities, their large-scale cultivation still poses a great challenge to the current microalgal industries. Open systems are cheap to install and operate, easy to clean and maintain, and have high surface area to volume ratio, suitable for microalgal culture. But they are susceptible to contamination, evaporative losses, and unfavourable weather conditions. In contrast, closed photobioreactor systems have high productivity, control of growth parameters, and minimum risk of contamination. But photobioreactors are expensive to install and difficult to operate and maintain. Therefore, an integration of thin layer cascade photobioreactors with a semi-closed setup was proposed that could be used to cultivate greater volumes of different microalgal species and generate different products such as proteins and lipids. This semi-closed photobioreactor system would have the benefits of both open systems and closed systems. An improved concept design had been illustrated and computational fluid dynamics (CFD) analysis using a simulation program (ANSYS) had also been performed to visualise the functionality and mechanism of the concept design. The CFD analysis revealed that the improved concept design of thin layer cascade semi-closed photobioreactor performed satisfactorily and was suitable for the cultivation of different microalgal species to produce proteins for fish feed and lipids for biodiesel

    Warm Sitz Bath: Are There Benefits after Transurethral Resection of the Prostate?

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    PURPOSE: We aimed to evaluate the efficacy of warm water sitz baths in patients who have undergone transurethral resection of the prostate (TURP) owing to lower urinary tract symptoms secondary to benign prostatic hyperplasia. MATERIALS AND METHODS: We reviewed the records of 1,783 patients who had undergone TURP between 2001 and 2009. In the warm water sitz bath group, patients were instructed to sit in a tub containing lukewarm water at 40-45degrees C for 10 minutes each time. Patients were advised to perform the procedure for at least 5 days immediately after the removal of a Foley urethral catheter. The differences in post-TURP complications between the warm water sitz bath group and the no sitz bath group were compared. RESULTS: After TURP, 359 of the 1,561 patients performed a warm water sitz bath. Complications after TURP, such as hemorrhage, urinary tract infection, urethral stricture, and acute urinary retention were found in 19 (5.3%) and 75 (6.2%) patients in the sitz bath and no sitz bath groups, respectively (p=0.09). There was a significant difference in postoperative complications such as urethral stricture between the warm sitz bath group and the no sitz bath group (p=0.04). The group that did not undergo warm water sitz bath treatment showed a 1.13-fold increased risk of rehospitalization within 1 month after TURP due to postoperative complications compared with the warm water sitz bath group (odds ratio [OR]=1.134; 95% confidence interval [CI], 1.022 to 1.193; p=0.06). CONCLUSIONS: Warm water sitz bath treatment reduced postoperative complications such as urethral stricture. These results suggest that large-scale prospective studies are needed to establish an ideal method and optimal duration of sitz baths.ope

    Quantum Cryptography Using Single Particle Entanglement

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    A quantum cryptography scheme based on entanglement between a single particle state and a vacuum state is proposed. The scheme utilizes linear optics devices to detect the superposition of the vacuum and single particle states. Existence of an eavesdropper can be detected by using a variant of Bell's inequality.Comment: 4 pages, 3figures, revte

    The Pomeron and Gauge/String Duality

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    The traditional description of high-energy small-angle scattering in QCD has two components -- a soft Pomeron Regge pole for the tensor glueball, and a hard BFKL Pomeron in leading order at weak coupling. On the basis of gauge/string duality, we present a coherent treatment of the Pomeron. In large-N QCD-like theories, we use curved-space string-theory to describe simultaneously both the BFKL regime and the classic Regge regime. The problem reduces to finding the spectrum of a single j-plane Schrodinger operator. For ultraviolet-conformal theories, the spectrum exhibits a set of Regge trajectories at positive t, and a leading j-plane cut for negative t, the cross-over point being model-dependent. For theories with logarithmically-running couplings, one instead finds a discrete spectrum of poles at all t, where the Regge trajectories at positive t continuously become a set of slowly-varying and closely-spaced poles at negative t. Our results agree with expectations for the BFKL Pomeron at negative t, and with the expected glueball spectrum at positive t, but provide a framework in which they are unified. Effects beyond the single Pomeron exchange are briefly discussed.Comment: 68 pages, uses JHEP3.cls, utphys.bst; references added, typos corrected, and clarifying remarks adde

    All-Electrical Skyrmionic Bits in a Chiral Magnetic Tunnel Junction

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    Topological spin textures such as magnetic skyrmions hold considerable promise as robust, nanometre-scale, mobile bits for sustainable computing. A longstanding roadblock to unleashing their potential is the absence of a device enabling deterministic electrical readout of individual spin textures. Here we present the wafer-scale realization of a nanoscale chiral magnetic tunnel junction (MTJ) hosting a single, ambient skyrmion. Using a suite of electrical and multi-modal imaging techniques, we show that the MTJ nucleates skyrmions of fixed polarity, whose large readout signal - 20-70% relative to uniform states - corresponds directly to skyrmion size. Further, the MTJ exploits complementary mechanisms to stabilize distinctly sized skyrmions at zero field, thereby realizing three nonvolatile electrical states. Crucially, it can write and delete skyrmions using current densities 1,000 times lower than state-of-the-art. These results provide a platform to incorporate readout and manipulation of skyrmionic bits across myriad device architectures, and a springboard to harness chiral spin textures for multi-bit memory and unconventional computing.Comment: 8 pages, 5 figure

    Targeting cancer addiction for SALL4 by shifting its transcriptome with a pharmacologic peptide

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    Sal-like 4 (SALL4) is a nuclear factor central to the maintenance of stem cell pluripotency and is a key component in hepatocellular carcinoma, a malignancy with no effective treatment. In cancer cells, SALL4 associates with nucleosome remodeling deacetylase (NuRD) to silence tumor-suppressor genes, such as PTEN. Here, we determined the crystal structure of an amino-terminal peptide of SALL4(1-12) complexed to RBBp4, the chaperone subunit of NuRD, at 2.7 Å, and subsequent design of a potent therapeutic SALL4 peptide (FFW) capable of antagonizing the SALL4-NURD interaction using systematic truncation and amino acid substitution studies. FFW peptide disruption of the SALL4-NuRD complex resulted in unidirectional up-regulation of transcripts, turning SALL4 from a dual transcription repressor-activator mode to singular transcription activator mode. We demonstrate that FFW has a target affinity of 23 nM, and displays significant antitumor effects, inhibiting tumor growth by 85% in xenograft mouse models. Using transcriptome and survival analysis, we discovered that the peptide inhibits the transcription-repressor function of SALL4 and causes massive up-regulation of transcripts that are beneficial to patient survival. This study supports the SALL4-NuRD complex as a drug target and FFW as a viable drug candidate, showcasing an effective strategy to accurately target oncogenes previously considered undruggable

    A Case of Mass-Forming Splenic Tuberculosis: MRI Findings with Emphasis of Diffusion-Weighted Imaging Characteristics

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    Tuberculosis remains one of the most prevalent and fatal infectious diseases in spite of considerable improvements in medical science. The diagnosis and treatment of extrapulmonary tuberculosis involving the abdomen is still complicated owing to vague or non-specific clinical features. Although rare, isolated splenic involvement is one of the important manifestations of extrapulmonary tuberculosis, and imaging suspicion of the disease is essential. We report a case of surgically confirmed mass-forming splenic tuberculosis showing a layered pattern consisting of caseous necrosis with profound restriction of water molecules surrounded by an irregular rind of granulation tissue with less diffusion restriction on diffusion-weighted magnetic resonance imaging (DWI). In the differential diagnosis of neoplastic or non-neoplastic mass-forming lesions involving the spleen, this unique DWI feature could be helpful in characterizing splenic tuberculosis. The patient has been in clinically disease free status for nearly 20 months after splenectomy

    Heat transfer enhancement by hybrid nano additives—Graphene nanoplatelets/cellulose nanocrystal for the automobile cooling system (Radiator)

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    A radiator is used to remove a portion of the heat generated by a vehicle engine. It is challenging to efficiently maintain the heat transfer in an automotive cooling system even though both internal and external systems need enough time to keep pace with catching up with evolving engine technology advancements. The effectiveness of a unique hybrid’s heat transfer nanofluid was investigated in this study. The hybrid nanofluid was mainly composed of graphene nanoplatelets (GnP), and cellulose nanocrystals (CNC) nanoparticles suspended in a 40:60 ratio of distilled water and ethylene glycol. A counterflow radiator equipped with a test rig setup was used to evaluate the hybrid nano fluid’s thermal performance. According to the findings, the proposed GNP/CNC hybrid nanofluid performs better in relation to improving the efficiency of heat transfer of a vehicle radiator. The suggested hybrid nanofluid enhanced convective heat transfer coefficient by 51.91%, overall heat transfer coefficient by 46.72%, and pressure drop by 34.06% with respect to distilled water base fluid. Additionally, the radiator could reach a better CHTC with 0.01% hybrid nanofluid in the optimized radiator tube by the size reduction assessment using computational fluid analysis. In addition to downsizing the radiator tube and increasing cooling capacity over typical coolants, the radiator takes up less space and helps to lower the weight of a vehicle engine. As a result, the suggested unique hybrid graphene nanoplatelets/cellulose nanocrystal-based nanofluids perform better in heat transfer enhancement in automobiles

    Successful and safe treatment of hemangioma with oral propranolol in a single institution

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    PurposeDramatic improvement of hemangioma to propranolol has been recently reported; however, details on dose and duration of treatment, potential risks, and monitoring have not been determined. The objective of this study is to describe and analyze the use of propranolol as a first-line treatment or as a single therapy in management of complicated hemangioma.MethodsA retrospective chart review of eight patients diagnosed with hemangioma and treated with propranolol in Kangbuk Samsung Hospital from February 2010 to April 2011 was performed.ResultsEight patients with hemangioma with functional impairment, cosmetic disfigurement, or rapid growth were treated with propranolol. Five patients had solitary facial hemangioma. The mean age of symptoms at onset was 5 weeks. The median age for starting propranolol treatment was 5.5 months. Propranolol at 2 mg/kg/day was finally administered in divided doses with a gradual increase. Significant regression was observed in seven patients, and shrinkage in size, softening in consistency, and decrease in redness were evident within 4 weeks. Among them, six patients were still taking propranolol, and one patient had stopped after 12 months. Other one patient did not show significant improvement with satisfactory result after 3 months of propranolol use. Treatment with propranolol was well tolerated and had few side effects. No rebound growth was observed in any of the patients.ConclusionWe observed that use of propranolol was very effective in treatment of hemangioma without obvious adverse effects or relapse

    Smartphone electrocardiogram for detecting atrial fibrillation after a cerebral ischaemic event: a multicentre randomized controlled trial

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    Aims: Atrial fibrillation (AF) is a preventable cause of ischaemic stroke but it is often undiagnosed and undertreated. The utility of smartphone electrocardiogram (ECG) for the detection of AF after ischaemic stroke is unknown. The aim of this study is to determine the diagnostic yield of 30-day smartphone ECG recording compared with 24-h Holter monitoring for detecting AF ≥30 s. Methods and results: In this multicentre, open-label study, we randomly assigned 203 participants to undergo one additional 24-h Holter monitoring (control group, n = 98) vs. 30-day smartphone ECG monitoring (intervention group, n = 105) using KardiaMobile (AliveCor®, Mountain View, CA, USA). Major inclusion criteria included age ≥55 years old, without known AF, and ischaemic stroke or transient ischaemic attack (TIA) within the preceding 12 months. Baseline characteristics were similar between the two groups. The index event was ischaemic stroke in 88.5% in the intervention group and 88.8% in the control group (P = 0.852). AF lasting ≥30 s was detected in 10 of 105 patients in the intervention group and 2 of 98 patients in the control group (9.5% vs. 2.0%; absolute difference 7.5%; P = 0.024). The number needed to screen to detect one AF was 13. After the 30-day smartphone monitoring, there was a significantly higher proportion of patients on oral anticoagulation therapy at 3 months compared with baseline in the intervention group (9.5% vs. 0%, P = 0.002). Conclusions: Among patients ≥55 years of age with a recent cryptogenic stroke or TIA, 30-day smartphone ECG recording significantly improved the detection of AF when compared with the standard repeat 24-h Holter monitoring. Keywords: Anticoagulation; Atrial fibrillation; Cryptogenic stroke; Digital health; Smartphone electrocardiogram.
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