A new method for non-labeling attomolar detection of diseases based on an individual gold nanorod immunosensor

Herein, we present the use of a single gold nanorod sensor for detection of diseases on an antibody-functionalized surface, based on antibody–antigen interaction and the localized surface plasmon resonance (LSPR) ?max shifts of the resonant Rayleigh light scattering spectra. By replacing the cetyltrimethylammonium bromide (CTAB), a tightly packed self-assembled monolayer of HS(CH2)11(OCH2CH2)6OCH2COOH(OEG6) has been successfully formed on the gold nanorod surface prior to the LSPR sensing, leading to the successful fabrication of individual gold nanorod immunosensors. Using prostate specific antigen (PSA) as a protein biomarker, the lowest concentration experimentally detected was as low as 111 aM, corresponding to a 2.79 nm LSPR ?max shift. These results indicate that the detection platform is very sensitive and outperforms detection limits of commercial tests for PSA so far. Correlatively, its detection limit can be equally compared to the assays based on DNA biobarcodes. This study shows that a gold nanorod has been used as a single nanobiosensor to detect antigens for the first time; and the detection method based on the resonant Rayleigh scattering spectrum of individual gold nanorods enables a simple, label-free detection with ultrahigh sensitivity.

DNA double strand break repair: a radiation perspective

SIGNIFICANCE:
Ionizing radiation (IR) can induce a wide range of unique deoxyribonucleic acid (DNA) lesions due to the spatiotemporal correlation of the ionization produced. Of these, DNA double strand breaks (DSBs) play a key role. Complex mechanisms and sophisticated pathways are available within cells to restore the integrity and sequence of the damaged DNA molecules.
RECENT ADVANCES:
Here we review the main aspects of the DNA DSB repair mechanisms with emphasis on the molecular pathways, radiation-induced lesions, and their significance for cellular processes.
CRITICAL ISSUES:
Although the main characteristics and proteins involved in the two DNA DSB repair processes present in eukaryotic cells (homologous recombination and nonhomologous end-joining) are reasonably well established, there are still uncertainties regarding the primary sensing event and their dependency on the complexity, location, and time of the damage. Interactions and overlaps between the different pathways play a critical role in defining the repair efficiency and determining the cellular functional behavior due to unrepaired/miss-repaired DNA lesions. The repair pathways involved in repairing lesions induced by soluble factors released from directly irradiated cells may also differ from the established response mechanisms.
FUTURE DIRECTIONS:
An improved understanding of the molecular pathways involved in sensing and repairing damaged DNA molecules and the role of DSBs is crucial for the development of novel classes of drugs to treat human diseases and to exploit characteristics of IR and alterations in tumor cells for successful radiotherapy applications.

Environmental Aspects of Underground Construction and Exploration of Underground Structure – State of the Art

An underground work (such as a tunnel or a cavern) has many, well known, environmental qualities such as: no physical barriers crossing the land, less maintenance costs than an analogous surface structure, less expenses for heating and conditioning; a localized emission of noise, gas, dust during operation and, finally, a better protection against seismic actions.
It cannot be forgotten, anyway, that some negative environmental features are present such as, for example, : perturbation, pollution and drainage of the groundwater; settlements; disposal of waste rock.
In the paper the above mentioned concepts are discussed and analysed to give a global overview of all this aspects.

An Excess of Risk-Increasing Low-Frequency Variants Can Be a Signal of Polygenic Inheritance in Complex Diseases

In most complex diseases, much of the heritability remains unaccounted for by common variants. It has been postulated that lower-frequency variants contribute to the remaining heritability. Here, we describe a method to test for polygenic inheritance from lower-frequency variants by using GWAS summary association statistics. We explored scenarios with many causal low-frequency variants and showed that there is more power to detect risk variants than to detect protective variants, resulting in an increase in the ratio of detected risk to protective variants (R/P ratio). Such an excess can also occur if risk variants are present and kept at lower frequencies because of negative selection. The R/P ratio can be falsely elevated because of reasons unrelated to polygenic inheritance, such as uneven sample sizes or asymmetric population stratification, so precautions to correct for these confounders are essential. We tested our method on published GWAS results and observed a strong signal in some diseases (schizophrenia and type 2 diabetes) but not others. We also explored the shared genetic component in overlapping phenotypes related to inflammatory bowel disease (Crohn disease [CD] and ulcerative colitis [UC]) and diabetic nephropathy (macroalbuminuria and end-stage renal disease [ESRD]). Although the signal was still present when both CD and UC were jointly analyzed, the signal was lost when macroalbuminuria and ESRD were jointly analyzed, suggesting that these phenotypes should best be studied separately. Thus, our method may also help guide the design of future genetic studies of various traits and diseases.

Classical and quantum aspects of multimode parametric interactions

Parametric interactions in nonlinear crystals represent a powerful tool in the optical manipulation of information, both in the classical and the quantum regime. Here, we analyze in detail classical and quantum aspects of three-and five-mode parametric interactions in chi(2) nonlinear crystals. The equations of motion are explicitly derived and then solved within the parametric approximation. We describe several applications, including holography, all-optical gates, generation of entanglement, and telecloning. Experimental results on the photon distributions and correlations of the generated beams are also reported and discussed.