35 research outputs found
Paternal effects on early embryogenesis
Historically, less attention has been paid to paternal effects on early embryogenesis than maternal effects. However, it is now apparent that certain male factor infertility phenotypes are associated with increased DNA fragmentation and/or chromosome aneuploidies that may compromise early embryonic development. In addition, there is a growing body of evidence that the fertilizing sperm has more function than just carrying an intact, haploid genome. The paternally inherited centrosome is essential for normal fertilization, and the success of higher order chromatin packaging may impact embryogenesis. Epigenetic modifications of sperm chromatin may contribute to the reprogramming of the genome, and sperm delivered mRNA has also been hythesized to be necessary for embryogenesis. There is less information about the epigenetic factors affecting embryogenesis than genetic factors, but the epigenetics of gamete and early embryogenesis is a rapidly advancing field
Cu<sub>0.89</sub>Zn<sub>0.11</sub>O, A New Peroxidase-Mimicking Nanozyme with High Sensitivity for Glucose and Antioxidant Detection
Nanomaterial-based
enzyme mimetics (nanozymes) is an emerging field
of research that promises to produce alternatives to natural enzymes
for a variety of applications. The search for the most cost-effective
and efficient inorganic nanomaterials, such as metal oxides, cannot
be won by pristine CuO. However, unlike CuO, the Zn-doped CuO (Zn-CuO)
nanoparticles reported in this paper reveal superior peroxidase-like
enzyme activity. This places Zn-CuO in a good position to participate
in a range of activities aimed at developing diverse enzyme applications.
The peroxidase-like activity was tested and confirmed against various
chromogenic substrates in the presence of H<sub>2</sub>O<sub>2</sub> and obeyed the Michaelis–Menten enzymatic pathway. The mechanism
of enhanced enzymatic activity was proved by employing terephthalic
acid as a fluorescence probe and by electron spin resonance. The nanozyme,
when tested for the detection of glucose, showed a substantial enhancement
in the detection selectivity. The limit of detection (LOD) was also
decreased reaching a limit as low as 0.27 ppm. Such a low LOD has
not been reported so far for the metal oxides without any surface
modifications. Moreover, the nanozyme (Zn-CuO) was utilized to detect
the three antioxidants tannic acid, tartaric acid, and ascorbic acid
and the relative strength of their antioxidant capacity was compared
Enumeration of T cells specific for RD1-encoded antigens suggests a high prevalence of latent Mycobacterium tuberculosis infection in healthy urban Indians.
Knowledge of the prevalence of latent Mycobacterium tuberculosis infection is crucial for effective tuberculosis control, but tuberculin skin test surveys have major limitations, including poor specificity because of the broad antigenic cross-reactivity of tuberculin. The M. tuberculosis RD1 genomic segment encodes proteins, such as early secretory antigenic target (ESAT)-6, that are absent from M. bovis bacille Calmette-Guérin (BCG) and most environmental mycobacteria. We recently identified circulating ESAT-6-specific T cells as an accurate marker of M. tuberculosis infection. Here, interferon-gamma-secreting T cells specific for peptides derived from ESAT-6 and a second RD1 gene product, CFP10, were enumerated in 100 prospectively recruited healthy adults in Bombay (Mumbai), India. Eighty percent responded to >/=1 antigen, and many donors had high frequencies of T cells that were specific for certain immunodominant peptides. In contrast, of 40 mostly BCG-vaccinated, United Kingdom-resident healthy adults, none responded to either antigen. This study suggests an 80% prevalence of latent M. tuberculosis infection in urban India
Graphene-Based “Hot Plate” for the Capture and Destruction of the Herpes Simplex Virus Type 1
The
study of graphene-based antivirals is still at a nascent stage
and the photothermal antiviral properties of graphene have yet to
be studied. Here, we design and synthesize sulfonated magnetic nanoparticles
functionalized with reduced graphene oxide (SMRGO) to capture and
photothermally destroy herpes simplex virus type 1 (HSV-1). Graphene
sheets were uniformly anchored with spherical magnetic nanoparticles
(MNPs) of varying size between ∼5 and 25 nm. Fourier-transform
infrared spectroscopy (FT-IR) confirmed the sulfonation and anchoring
of MNPs on the graphene sheets. Upon irradiation of the composite
with near-infrared light (NIR, 808 nm, 7 min), SMRGO (100 ppm) demonstrated
superior (∼99.99%) photothermal antiviral activity. This was
probably due to the capture efficiency, unique sheet-like structure,
high surface area, and excellent photothermal properties of graphene.
In addition, electrostatic interactions of MNPs with viral particles
appear to play a vital role in the inhibition of viral infection.
These results suggest that graphene composites may help to combat
viral infections including, but not only, HSV-1