DFT Study of WS2-Based Nanotubes Electronic Properties under Torsion Deformations.

In this study, the influence of torsional deformations on the properties of chiral WS2-based nanotubes was investigated. All calculations presented in this study were performed using the density functional theory (DFT) and atomic gaussian type orbitals basis set. Nanotubes with chirality indices (8, 2), (12, 3), (24, 6) and (36, 9) corresponding to diameters of 10.68 Å, 14.90 Å, 28.26 Å and 41.90 Å, respectively, are examined. Our results reveal that for nanotubes with smaller diameters, the structure obtained through rolling from a slab is not optimal and undergoes spontaneous deformation. Furthermore, this study demonstrates that the nanotube torsion deformation leads to a reduction in the band gap. This observation suggests the potential for utilizing such torsional deformations to enhance the photocatalytic activity of the nanotubes.

Formation of Gold Nanoparticle Self-Assembling Films in Various Polymer Matrices for SERS Substrates.

Surface-enhanced Raman spectroscopy (SERS) is regarded as a versatile tool for studying the composition and structure of matter. This work has studied the preparation of a SERS substrate based on a self-assembling plasmonic nanoparticle film (SPF) in a polymer matrix. Several synthesis parameters for the SPF are investigated, including the size of the particles making up the film and the concentration and type of the self-assembling agent. The result of testing systems with different characteristics is discussed using a model substance (pseudoisocyanin iodide). These models can be useful in the study of biology and chemistry. Research results contain the optimal parameters for SPF synthesis, maximizing the SERS signal. The optimal procedure for SPF assembly is determined and used for the synthesis of composite SPFs within different polymer matrices. SPF in a polymer matrix is necessary for the routine use of the SERS substrate for various types of analytes, including solid samples or those sensitive to contamination. Polystyrene, polyvinyl alcohol (PVA), and polyethylene are investigated to obtain a polymer matrix for SPF, and various methods of incorporating SPF into a polymer matrix are being explored. It is found that films with the best signal enhancement and reproducibility were obtained in polystyrene. The minimum detectable concentration for the SERS substrate obtained is equal to 10-10 M. We prepared a SERS substrate with an analytical enhancement factor of 2.7 × 104, allowing an increase in the detection sensitivity of analyte solutions of five orders of magnitude.

Development and validation of a spontaneous preterm delivery predictor in asymptomatic women.

BACKGROUND: Preterm delivery remains the leading cause of perinatal mortality. Risk factors and biomarkers have traditionally failed to identify the majority of preterm deliveries. OBJECTIVE: To develop and validate a mass spectrometry-based serum test to predict spontaneous preterm delivery in asymptomatic pregnant women. STUDY DESIGN: A total of 5501 pregnant women were enrolled between 17(0/7) and 28(6/7) weeks gestational age in the prospective Proteomic Assessment of Preterm Risk study at 11 sites in the United States between 2011 and 2013. Maternal blood was collected at enrollment and outcomes collected following delivery. Maternal serum was processed by a proteomic workflow, and proteins were quantified by multiple reaction monitoring mass spectrometry. The discovery and verification process identified 2 serum proteins, insulin-like growth factor-binding protein 4 (IBP4) and sex hormone-binding globulin (SHBG), as predictors of spontaneous preterm delivery. We evaluated a predictor using the log ratio of the measures of IBP4 and SHBG (IBP4/SHBG) in a clinical validation study to classify spontaneous preterm delivery cases (<37(0/7) weeks gestational age) in a nested case-control cohort different from subjects used in discovery and verification. Strict blinding and independent statistical analyses were employed. RESULTS: The predictor had an area under the receiver operating characteristic curve value of 0.75 and sensitivity and specificity of 0.75 and 0.74, respectively. The IBP4/SHBG predictor at this sensitivity and specificity had an odds ratio of 5.04 for spontaneous preterm delivery. Accuracy of the IBP4/SHBG predictor increased using earlier case-vs-control gestational age cutoffs (eg, <35(0/7) vs ≥35(0/7) weeks gestational age). Importantly, higher-risk subjects defined by the IBP4/SHBG predictor score generally gave birth earlier than lower-risk subjects. CONCLUSION: A serum-based molecular predictor identifies asymptomatic pregnant women at risk of spontaneous preterm delivery, which may provide utility in identifying women at risk at an early stage of pregnancy to allow for clinical intervention. This early detection would guide enhanced levels of care and accelerate development of clinical strategies to prevent preterm delivery.

Prevalence of dental trauma and use of mouthguards in rugby union players.

BACKGROUND: There is a high prevalence of orofacial trauma in rugby union players. Mouthguards reduce complications following dental injuries, should dental injuries occur. The aim of this study was to investigate the prevalence of oral trauma and the significance of mouthguard use in adult amateur rugby union players in New South Wales, Australia. METHODS: Questionnaires were distributed to players in rugby union clubs. It questioned players about their mouthguard use and orofacial trauma experience; the type of injury, complications, if a mouthguard was worn, where treatment was sought and outcome. RESULTS: The prevalence of orofacial trauma in rugby union players is 64.9%. The most common injury was laceration to intraoral and extraoral soft tissues at 44.5%. Of all orofacial injuries reported, 41.9% were to the dentition. Following dental injury, loss of the tooth was the most common complication (34.7%). 76.9% of players wore mouthguards. By wearing a mouthguard, the risk reduction for ongoing complications following dental injuries was 18.5% (p-value = 0.009). Of these, 10.4% (p-value = 0.45) represented loss of the tooth. CONCLUSIONS: Rates of orofacial trauma and complications in amateur rugby union players are high in Australia. Use of mouthguards results in significant risk reduction for complications following dental injuries, including loss of tooth.

3-Hy-droxy-2-(4-meth-oxy-phen-yl)-4H-chromen-4-one.

In the title compound, C(16)H(12)O(4), the benzene ring is twisted at an angle of 12.3 (1)° relative to the 4H-chromene skeleton, and an intramolecular O-H⋯O hydrogen bond occurs. The meth-oxy group is almost coplanar with the benzene ring [1.5 (1)°]. In the crystal, inversely oriented mol-ecules are arranged in double (A, A') columns, along the b axis, and are linked by a network of inter-molecular O-H⋯O hydrogen bonds (between A and A') and C-H⋯π contacts (within A or A'). The 4H-chromene cores are parallel within A or A', but make a dihedral angle of 88.6 (1)° between A and A'.

2-(4-Fluoro-phen-yl)-3-hy-droxy-4H-chromen-4-one.

In the crystal structure of the title compound, C(15)H(9)FO(3), inversely oriented mol-ecules form inversion dimers through pairs of O-H⋯O hydrogen bonds. The benzene ring is twisted at an angle of 12.0 (1)° relative to the 4H-chromene skeleton of the mol-ecule. Adjacent 4H-chromene units are parallel in a given column or oriented at an angle of 50.0 (1)° in neighboring, inversely oriented, columns, forming a herringbone pattern.