389 research outputs found

    Efficient hematite photoanodes prepared by hydrochloric acid-treated solutions with amphiphilic graft copolymer

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    Simple and low-cost approaches for the preparation of photoelectrodes are crucial to enable a transition towards a sustainable and circular economy in which sunlight energy is efficiently harnessed and used. Here, a novel and simple process is presented to prepare a sol solution that can be cast by spin coating deposition for mesoporous α-Fe2O3 hematite water-splitting photoanodes, reaching 1.05 mA cm−2 at 1.23 VRHE under 1 sun illumination. The sol solution is prepared using inexpensive commercial ∼10 nm α-Fe2O3 hematite nanoparticles as hematite film precursor, an amphiphilic poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer as a pore template, and HCl acid as an iron oxide phase directing agent. The hydrophilic POEM side chains selectively interact with HCl-treated hematite nanoparticles allowing their dispersion. Moreover, the HCl in the sol solution disperses and dissolves the hematite nanoparticles which re-precipitate as mixed phase γ-FeOOH and β-FeOOH, leading to better performant hematite films due to finer nanostructures, a more pronounced hematite (110) plane, and a more hydroxylated surface. This work demonstrates that synergies between an amphiphilic graft copolymer, hematite nanoparticles and HCl acid can be exploited in the inexpensive spin coating technique to prepare robust, stable and promising hematite photoanodes for energy devices.</p

    Incidence and Risk Factors Associated with Superior Mesenteric Artery Syndrome following Surgical Correction of Scoliosis

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    STUDY DESIGN: Retrospective study. PURPOSE: To more accurately determine the incidence and clarify risk factors. OVERVIEW OF LITERATURE: Superior mesenteric artery syndrome is one of the possible complications following correctional operation for scoliosis. However, when preliminary symptoms are vague, the diagnosis of superior mesenteric artery syndrome may be easily missed. METHODS: We conducted a retrospective study using clinical data from 118 patients (43 men and 75 women) who underwent correctional operations for scoliosis between September 2001 and August 2007. The mean patient age was 15.9 years (range 9~24 years). The risk factors under scrutiny were the patient body mass index (BMI), change in Cobb's angle, and trunk length. RESULTS: The incidence of subjects confirmed to have obstruction was 2.5%. However, the rate increased to 7.6% with the inclusion of the 6 subjects who only showed clinical symptoms of obstruction without confirmative study. The BMI for the asymptomatic and symptomatic groups were 18.4+/-3.4 and 14.6+/-3, respectively. The change in Cobb's angle for the asymptomatic and symptomatic groups were 24.8+/-13.6 degrees and 23.4+/-9.1 degrees , respectively. The change in trunk length for the asymptomatic and symptomatic groups were 2.3+/-2.1 cm and 4.5+/-4.8 cm, respectively. Differences in Cobb's angle and the change in trunk length between the two groups did not reach statistical significance, although there was a greater increase in trunk length for the symptomatic group than for the asymptomatic group. CONCLUSIONS: Our study shows that the incidence of superior mesenteric artery syndrome may be greater than the previously accepted rate of 4.7%. Therefore, in the face of any early signs or symptoms of superior mesenteric artery syndrome, prompt recognition and treatment are necessaryope

    Low-Profile Dual-Wideband MIMO Antenna with Low ECC for LTE and Wi-Fi Applications

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    This paper presents a low-profile dual-wideband multiple input multiple output (MIMO) antenna with low envelop correlation coefficient (ECC) for long-term evolution (LTE) and wireless fidelity (Wi-Fi) applications. The antenna covers LTE band 7 and Wi-Fi as well as wireless broadband (Wibro) and Worldwide Interoperability for Microwave Access (WiMax) (except for the 3.5-GHz band). To aid with integration of a practical mobile terminal, the MIMO antenna elements are placed at appropriate locations by analyzing the surface current distribution and without using any additional isolation techniques. The measured bandwidths with reflection coefficients of <−10 dB are 36.8% in the range 2.02–2.93 GHz and 23.4% in the range 5.10–6.45 GHz. Isolation is satisfied to be >20 dB in the operating frequency ranges of both LTE band 7 and Wi-Fi. Additionally, the calculated ECC is in the range 0.005<ρ<0.025, which is considerably lower than the ρ<0.5 required for MIMO applications. The measured radiation patterns are appropriate for mobile terminals, and omnidirectional radiation patterns are obtained

    Efficient hematite photoanodes prepared by hydrochloric acid-treated solutions with amphiphilic graft copolymer

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    Porous frameworks of iron oxide (Fe2O3) were prepared by templating with a hydrophobic-hydrophilic graft co-polymer which showed high generated photocurrents under sunlight equivalent illumination. This dataset contains the TEM (transmission electron microscopy) and SEM (scanning electron microscopy) images and raw infrared data.Photocurrent Densities were calculated from generated potential under illumination (at 1 sun equivalent) measured with an Ivium potentiostat and using Ivium Technologies IviumSoft software Release 2.031. Further methodological details may be found in the Experimental Section of the associated manuscript.Data was collected using the PhotoElectroChemical apparatus located in a research laboratory of Dr Salvador Eslava located in Dept of Chemical Engineering, University of Bath. Electron microscopy was conducted at the Microscopy and Analysis Suite, University of Bath. An Ivium Compactstat pontentiostat with associated illumination apparatus and quartz sample cell were employed for photocurrent measurements

    Comparison of Surgical Outcomes in Thoracolumbar Fractures Operated with Posterior Constructs Having Varying Fixation Length with Selective Anterior Fusion

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    PURPOSE: Surgical treatment in the case of thoracolumbar burst fractures is very controversial. Posterior instrumentation is most frequently used, however, but the number of levels to be instrumented still remains a matter of debate. MATERIALS AND METHODS: A total of 94 patients who had a single burst fracture between T11 and L2 were selected and were managed using posterior instrumentation with anterior fusion when necessary. They were divided into three groups as follows; Group I (n = 28) included patients who were operated by intermediate segment fixation, Group II (n = 32) included patients operated by long segment fixation, and Group III (n = 34) included those operated by intermediate segment fixation with a pair of additional screws in the fractured vertebra. The mean follow-up period was twenty one months. The outcomes were analyzed in terms of kyphosis angle (KA), regional kyphosis angle (RA), sagittal index (SI), anterior height compression rate, Frankel classification, and Oswestry Disability Index questionnaire. RESULTS: In Groups II and III, the correction values of KA, RA, and SI were much better than in Group I. At the final follow up, the correction values of KA (6.3 and 12.1, respectively) and SI (6.2 and 12.0, respectively) were in Groups II and III found to be better in the latter. CONCLUSION: The intermediate segment fixation with an additional pair of screws at the fracture level vertebra gives results that are comparable or even better than long segment fixation and gives an advantage of preserving an extra mobile segment.ope

    Treatment outcomes of stereotactic body radiation therapy for pulmonary metastasis from sarcoma: a multicenter, retrospective study

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    Purpose The aim of this study was to evaluate the treatment outcomes and potential dose-response relationship of stereotactic body radiation therapy (SBRT) for pulmonary metastasis of sarcoma. Materials and methods A retrospective review of 39 patients and 71 lesions treated with SBRT from two institutions was performed. The patients had oligometastatic or oligoprogressive disease, or were receiving palliation. Doses of 20–60Gy were delivered in 1–5 fractions. The local control per tumor (LCpT) was evaluated according to the biologically effective dose with an α/β ratio of 10 (BED10) of the prescribed dose (BED10 ≥ 100Gy vs. BED10 < 100Gy). Clinical outcomes per patient, including local control per patient (LCpP), pulmonary progression-free rate (PPFR), any progression-free rate (APFR), and overall survival (OS) were investigated. Results The median follow-up period was 27.2 months. The 1-, 2-, and 3-year LCpT rates for the entire cohort were 100.0%, 88.3%, and 73.6%, respectively. There was no observed difference in LCpT between the two BED10 groups (p = 0.180). The 3-year LCpP, PPFR, APFR, and OS rates were 78.1%, 22.7%, 12.9%, and 83.7%, respectively. Five (12.8%) patients with oligometastasis had long-term disease-free intervals, with a median survival period of 40.7 months. Factors that were associated with a worse prognosis were oligoprogression (vs. oligometastasis), multiple pulmonary metastases, and simultaneous extrathoracic metastasis. Conclusion SBRT for pulmonary metastasis of sarcoma is effective. Some selected patients may achieve durable response. Considerations of SBRT indication and disease extent may be needed as they may influence the prognosis.This work was supported by the National Research Foundation of Korea grant funded by the Korean Government (2022R1A2C1092928)

    Site-directed mutagenesis of the amino acid residues in β-strand III [Val30-Val36] of d-amino acid aminotransferase of Bacillus sp. YM-1

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    AbstractThe β-strand III formed by amino acid residues Val30-Val36 is located across the active site of the thermostable d-amino acid aminotransferase (d-AAT) from thermophilic Bacillus sp. YM-1, and the odd-numbered amino acids (Tyr31, Val33, Lys35) in the strand are revealed to be directed toward the active site. Interestingly, Glu32 is also directed toward the active site. We first investigated the involvement of these amino acid residues in catalysis by alanine scanning mutagenesis. The Y31A and E32A mutant enzymes showed a marked decrease in kcat value, retaining less than 1% of the wild-type enzyme activity. The kcat values of V33A and K35A were changed slightly, but the Km of K35A for α-ketoglutarate was increased to 35.6 mM, compared to the Km value of 2.5 mM for the wild-type enzyme. These results suggested that the positive charge at Lys35 interacted electrostatically with the negative charge at the side chain of α-ketoglutarate. Site-directed mutagenesis of the Glu32 residue was conducted to demonstrate the role of this residue in detail. From the kinetic and spectral characteristics of the Glu32-substituted enzymes, the Glu32 residue seemed to interact with the positive charge at the Schiff base formed between the aldehyde group of pyridoxal 5′-phosphate (PLP) and the ε-amino group of the Lys145 residue

    Pseudotumor of the Omentum Associated with Migration of the Ingested Crab-Leg

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    Foreign body ingestion is not uncommon in clinical practice, and it may occasionally lead to penetration injuries. Emergency physicians and radiologists sometimes fail to obtain complete histories including ingestion and may overlook the possibility of foreign body-induced complications. Herein, we report a case of stomach antrum perforation due to foreign body migration. We were unaware of the patient's history of eating the Korean delicacy "Kanjang-gaejang," which is raw crab seasoned with soy sauce. Several imaging diagnostic modalities had suggested the possibility of a malignant mass in the gastrocolic ligament area. During the operation, a crab leg was discovered as the cause of an intra-abdominal abscess. The patient underwent an antrectomy, a vagotomay, and a transverse colon wedge resection. We present this unusual case of a pseudotumorous lesion caused by ingestion of Kanjang-gaejang
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