Sulfurized Co-Mo Alloy Thin Films as Efficient Electrocatalysts for Hydrogen Evolution Reaction

Catalysis Letters - Here, we successfully fabricated sulfurized Co-Mo alloy thin film electrodes with different compositions and studied their catalytic properties for hydrogen evolution reaction...     

The evolution of clinical periodontal therapy

Periodontal diseases are considered as old as the history of mankind, Magical, religious and herbal treatments were demonstrated in almost all of the early writings. However, methodical, carefully reasoned therapeutic approaches did not exist until the middle-ages and modern treatment with a scientific base and sophisticated instrumentation did not develop until the 18th century. Prior to the 1950s, diseases were mostly treated by root debridement and the extraction of the affected teeth. Until the 1970s, it was primarily the symptoms of periodontal diseases that were treated. The goal was radical elimination of the periodontal pocket (resective therapy). The means were gingivectomy, flap procedures and osseous surgery. The disadvantages were the massive sacrifice of periodontal tissues, lack of regeneration and clinically elongated teeth. These disadvantages, along with the realization of the importance of aetiologic agents, raised questions about the necessity of total pocket elimination, and the control of subgingival infection by a thorough scaling and root planing (nonsurgical therapy), with and without antibiotics, became a commonly used treatment during the 1980s. Comparative longitudinal studies, surgical versus nonsurgical, demonstrated that both surgical and nonsurgical therapy result in limited regeneration and healing with a long junctional epithelium. The most important aspects of today's modern concept of periodontal therapy are causal, regenerative, and specific for disease type and severity. Although the regeneration of the periodontium can be accomplished with the biological principles of guided tissue regeneration and graft materials, compared to conventional methods, the restoration of a completely normal periodontal status has not yet been achieved. We are about to reach our ultimate goals and presently, the more promising research directions for a substantial regeneration seems to lie in biological mediators. Although the future of periodontal therapy is bright, it is still of critical importance to have a preventive strategy to keep individuals healthy beforehand.     

Fe-Doped High Purity GaAs as a Room Temperature Gamma-Ray Spectrometric Detector

Fe-doped high purity GaAs crystals have been grown using a vertical-type liquid-phase epitaxial technique and have been studied as room temperature gamma-ray spectrometric detectors for nuclear fuel safeguards. To improve the detector gamma-ray counting efficiency, a double-epitaxial-layer detector was studied.     

Biobased Poly-phosphonate Additives from Methyl Linoleates‡

Poly-dialkyl phosphonates were synthesized by reacting methyl linoleate with dimethyl, diethyl, and di-n-butyl phosphites in the presence of free radical initiator and positively identified and characterized using gas chromatography–mass spectrometry (GC-MS), nuclear magnetic resonance (NMR; ¹H, ¹³C, ³¹P), and Fourier transform infrared (FTIR). Neat poly-dialkyl phosphonates and their blends in high-oleic sunflower oil (HOSuO) and polyalphaolefin (PAO-6) base oils were investigated for their physical, chemical, and tribological properties. At room temperature, the poly-dialkyl phosphonates displayed much better solubility in HOSuO than in PAO-6. Solubility in the base oils increased in the order dimethyl?<?diethyl?<?di-n-butyl. Relative to methyl linoleate, the neat poly-dialkyl phosphonates displayed higher density, higher kinematic viscosity, higher oxidation stability, and better cold flow (lower pour point and cloud point) properties. As an additive (0–10% w/w) in HOSuO, increasing concentration of poly-di-n-butyl phosphonate resulted in increasing onset and peak oxidation temperatures and decreasing cloud point. Poly-di-n-butyl phosphonate blends in HOSuO also showed lower four-ball antiwear (AW) coefficient of friction (COF) and wear scar diameter (WSD) than corresponding blends with zinc dialkyl dithiophosphate (ZDDP). As an additive (0–10% w/w) in PAO-6 base oil, poly-di-n-butyl phosphonate displayed lower four-ball antiwear COF and comparable WSD relative to similar blends of ZDDP in PAO-6. The results indicate that poly-dialkyl phosphonates are promising biobased AW additives with comparable or better performance than current petroleum-based commercial AW additives such as ZDDP.     

Differences observed in properties of ternary NiCoFe films electrodeposited at low and high pH

Ternary NiCoFe films were potentiostatically electrodeposited from the electrolytes with low (3.0) and high (3.6) pH levels, and differences in their compositional, structural, magnetic and magnetoresistance properties were studied. The compositional analysis demonstrated that the Ni content in the films decreased, and Co and Fe content increased while electrolyte pH was changed from low to high level. The structural analysis of the films was carried out using the X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The XRD data revealed that the films have a strong (111) texture of the face-centred cubic (fcc) structure at low pH, while for the films at high pH a mixture of dominantly fcc and hexagonal closed packed structure was observed. The SEM studies showed that films grown at low pH level had comparatively larger grains than those at high pH. The magnetic characteristics studied by a vibrating sample magnetometer and magnetotransport properties were seen to be changed by the electrolyte pH. However, all films have in-plane magnetic anisotropy. The differences observed in the magnetic and magnetotransport properties were attributed to the microstructural changes caused by the electrolyte pH.     

Laparoscopic-assisted pneumatic reduction of intussusception

Operative mortality for 262 infants with interruption of the aortic arch repaired from 1982 to June 1993 has remained constant at about 35%. Major coexistent cardiac malformations, type B interruption, or staged repair are risk factors for mortality.     

Radiologic evaluation of gastrointestinal leiomyosarcomatosis

A 68-year-old woman who had previously undergone small intestinal resection because of leiomyosarcoma was referred to our clinic with epigastric pain. A double-contrast barium study and the subsequent abdominopelvic CT and abdominal MRI examinations demonstrated multiple extraluminal growing tumors arising from the walls of stomach, small bowel, and colon. A CT-guided aspiration biopsy revealed malignant mesenchymal tumor. The presence of disseminated intra-abdominal masses without concomitant ascites and invasion of tissue planes on CT in a patient operated on prior because of a leiomyosarcoma led to the diagnosis of gastrointestinal leiomyosarcomatosis. In this report we discuss the radiological approach to this rare entity.     

A new journal power-weakness ratio to measure journal impact

Scientometrics - Journal impact indicators are useful measures to determine the relative importance of journals within a given discipline. By recasting the journal cross-citation matrix as a...