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Rapid laboratory technologies which can effectively distinguish active tuberculosis (ATB) from controls and latent tuberculosis infection (LTBI) are lacked.The objective of this study is to explore MTB biomarkers in serum that can distinguish ATB from LTBI.We constructed a tuberculosis protein microarray containing 64 MTB associated antigens. We then used this microarray to screen 180 serum samples, from patients with ATB and LTBI, and healthy volunteer controls. Both SAM (Significance analysis of microarrays) and ROC curve analysis were used to identify the differentially recognized biomarkers between groups. Extra 300 serum samples from patients with ATB and LTBI, and healthy volunteer controls were employed to validate the identified biomarkers using ELISA-based method.According to the results, the best biomarker combinations of 4 proteins (Rv1860, RV3881c, Rv2031c and Rv3803c) were selected. The biomarker panel containing these 4 proteins has reached a sensitivity of 93.3% and specificity of 97.7% for distinguishing ATB from LTBI, and a sensitivity of 86% and specificity of 97.6% for distinguishing ATB from HC.The biomarker combination in this study has high sensitivity and specificity in distinguishing ATB from LTBI, suggesting it is worthy for further validation in more clinical samples.

Co-crystals have great potential for drug research and development because the formation of co-crystal is accompanied by changes inter-molecular interactions between starting materials that enable to improve both physical and chemical properties of active pharmaceutical ingredients. In order to provide a more profound insight into the structural changes of specific drugs upon co-crystallization, spectroscopic characterization of solid-state acetazolamide (ACZ), 4-hydroxybenzoic acid (4HBA) and their co-crystal prepared by mechanical grinding approach has been performed with spectral techniques including terahertz time-domain spectroscopy (THz-TDS) and Raman spectroscopy. Experimental THz spectra show that the ACZ-4HBA co-crystal has a few significantly different absorption peaks in 0.82, 1.16, 1.28 and 1.64 THz respectively compared with parent materials in the frequency region from 0.2 to 1.8 THz. Likewise, such differences between the co-crystal and starting compounds could also be characterized by Raman vibrational spectra. Moreover, density functional theory (DFT) calculations were performed to simulate optimized structures and vibrational modes of three kind of possible co-crystal theoretical forms (form I, II and III) between ACZ and 4HBA. Theoretical results and THz/Raman vibrational spectra of ACZ-4HBA co-crystal show that the 4HBA links to the thiadiazole acetamide fragment of ACZ via the double-bridged heterodimeric synthon C(N)NH⋯HOOC inter-molecular hydrogen bonding interaction establishing the theoretical form I, which is more consistent with experimental observations than other two possible theoretical co-crystal forms. These results provide rich information and unique method for characterizing the composition of co-crystal structures and also inter-molecular interactions shown within pharmaceutical co-crystallization process at the molecular level.

Vibrational modes of 2-thiobarbituric acid (TBA) tautomeric polymorphs (form I, II and IV) were characterized by terahertz time-domain spectroscopy (THz-TDS) and Raman spectral techniques. The experimental results indicate that both vibrational spectroscopy techniques could be used to recognize the above TBA three tautomeric forms clearly. Experimental THz spectral results show that each of TBA tautomeric polymorphs has distinctive fingerprint peaks in the terahertz region. Raman spectra also show similar results about differences of TBA tautomeric polymorphs, but not significant as that of terahertz spectra since Raman-active vibrational modes are mostly from intra-molecular interaction of various functional groups within the specific molecule while that of terahertz region is more sensitive to inter-molecular interaction within crystalline unit cells. In addition, density functional theory (DFT) was used to simulate the optimized structures and vibrational modes of these three TBA tautomeric forms above. The characteristic vibrational modes of TBA polymorphs are assigned comparing the simulated DFT results with experimental vibrational spectra. The results provide fundamental benchmark for the study of pharmaceutical polymorphism based on both Raman and terahertz vibrational spectroscopic techniques combined with theoretical simulations.

Metallic nanoparticles have unique optical properties such as localized surface plasmon resonance (LSPR) effect, which can be used to improve the energy absorption and photocatalytic properties of semiconductor bases. In this paper, we construct a model to study the influence of Ag or Au nanoparticles (cubes or spheres) on the solar energy absorption and photocatalytic properties of nitrogen doped TiO 2 (or N-TiO 2 ). Effects of specific nanoparticle coupling parameters, such as particle shape, size, doping period (metal–metal distance) and separation distance (metal–semiconductor distance), on the properties of N-TiO 2 are studied in detail. We show that the photocurrent improvement can be optimized by setting suitable geometric parameters. In particular, the separation distance between metallic nanoparticles and N-TiO 2 D should be around 6–7 nm, and the period of doping P should be around 360 nm. The silver cubes with edge length L = 120 n m show the best performance. The results can help the design of solar energy materials, in which metallic nanoparticles may play an important role.

Graphene has great potential for fabrication of ultrafast opto-electronics, in which relaxation and transport of photoexcited carriers determine device performance. Even though ultrafast carrier relaxation in graphene has been studied vigorously, transport properties of photoexcited carriers in graphene are largely unknown. In this work, we utilize an ultrafast grating imaging technique to measure lifetime (τr), diffusion coefficient (D), diffusion length (L) and mobility (μ) of photoexcited carriers in mono- and multi-layer graphene non-invasively. In monolayer graphene, D∼10,000 cm2/s and μ∼120,000 cm2/V have been observed, both of which decrease drastically in multilayer graphene, indicating that the remarkable transport properties in monolayer graphene originate from its unique Dirac-Cone energy structure. Mobilities of photoexcited carriers measured here are several times larger than the Hall and Field-Effect mobilities reported in literature (

In order to characterize molecular structures of 2,4,6-trihydroxybenzoic acid (PCA) by means of vibrational spectroscopic techniques, we report investigation of PCA monohydrated form and its anhydrous polymorphic one by using terahertz and Raman spectral characterization. The experimental THz spectra show that the monohydrated PCA only has two absorption bands at 0.69 and 1.65 THz respectively in the frequency region from 0.2 to 1.8 THz, meanwhile the anhydrous form has a few significantly different absorption bands at 0.75, 1.01, 1.46 and 1.64 THz, respectively. Furthermore, Raman spectra characterized such differences of vibrational modes shown within 200–1800 cm−1 region about the monohydrated and anhydrous forms of PCA. In view of various possible theoretical structural forms that may exist in anhydrous PCA and its monohydrated one, density functional theory calculations were performed to simulate optimized structures and vibrational mode of above two PCA polymorphic forms. Theoretical results and experimental THz/Raman spectra of anhydrous PCA show that the dimer synthon via the carboxylic group ••• carboxyl group and its ortho-phenolic hydroxyl group inter-molecular hydrogen bonding interaction establishing the theoretical form I (AH-I) is more consistent with experimental observation than other theoretical forms (AH-II and AH-III). Meanwhile, the theoretical monohydrated form I (MH-I), which is formed by the linkage of carboxyl group and its ortho-phenolic hydroxyl group with water molecule, is also much more agreement with experimental spectral observations of PCA monohydrate than other monohydrated forms (MH-II and MH-III). Our study demonstrates effectively qualitative analysis of both micro-molecular structures and dehydrated transitions between anhydrous and hydrated polymorphic forms of PCA, thus providing rich information on the corresponding structural changes of anhydrous and hydrated PCAs due to various inter-molecular and intra-molecular interactions based on their finger-print vibrational spectra combined with theoretical simulations.

In this work, thermodynamic phenomena in crystalline silicon irradiated by an ultrafast laser pulse were studied using the method of molecular dynamics simulations. The Stillinger–Weber potential was used to model the crystalline silicon. The temperature development in silicon when heated by an ultrafast laser pulse was tracked. Melting and resolidification processes and the resulting structural change were investigated. Radial Distribution Functions were used to track the liquid-amorphous interface during resolidification. It was found that the temperature at the solid–liquid interface could deviate from the equilibrium melting temperature by several hundred degrees. After the melted layer was solidified, some melted material became crystalline and the rest of the material remained in an amorphous state. The difference in the final state was associated with the rate of resolidification and both of the qualitative and quantitative analyses of the relationship between the final atom structure and resolidification rate were made.

We report the STAR measurement of ϕ meson production in Au + Au and p + p collisions at s N N = 200 GeV . Using the event mixing technique, the ϕ spectra and yields are obtained at mid-rapidity for five centrality bins in Au + Au collisions and for non-singly-diffractive p + p collisions. It is found that the ϕ transverse momentum distributions from Au + Au collisions are better fitted with a single-exponential while the p + p spectrum is better described by a double-exponential distribution. The measured nuclear modification factors indicate that ϕ production in central Au + Au collisions is suppressed relative to peripheral collisions when scaled by the number of binary collisions ( 〈 N bin 〉 ) . The systematics of 〈 p t 〉 versus centrality and the constant ϕ / K − ratio versus beam species, centrality, and collision energy rule out kaon coalescence as the dominant mechanism for ϕ production.