bSerpins are ubiquitously distributed serine protease inhibitors that covalently bind to target proteases to exert their activities. Serpins regulate a wide range of activities, particularly those in which protease-mediated cascades are active. The Drosophila melanogaster serpin Spn43Ac negatively controls the Toll pathway that is activated in response to fungal infection. The entomopathogenic fungus Beauveria bassiana offers an environmentally friendly alternative to chemical pesticides for insect control. However, the use of mycoinsecticides remains limited in part due to issues of efficacy (low virulence) and the recalcitrance of the targets (due to strong immune responses). Since Spn43Ac acts to inhibit Toll-mediated activation of defense responses, we explored the feasibility of a new strategy to engineer entomopathogenic fungi with increased virulence by expression of Spn43Ac in the fungus. Compared to the 50% lethal dose (LD 50 ) for the wild-type parent, the LD 50 of B. bassiana expressing Spn43Ac (strain Bb::S43Ac-1) was reduced ϳ3-fold, and the median lethal time against the greater wax moth (Galleria mellonella) was decreased by ϳ24%, with the more rapid proliferation of hyphal bodies being seen in the host hemolymph. In vitro and in vivo assays showed inhibition of phenoloxidase (PO) activation in the presence of Spn43Ac, with Spn43Ac-mediated suppression of activation by chymotrypsin, trypsin, laminarin, and lipopolysaccharide occurring in the following order: chymotrypsin and trypsin > laminarin > lipopolysaccharide. Expression of Spn43Ac had no effect on the activity of the endogenous B. bassianaderived cuticle-degrading protease (CDEP-1). These results expand our understanding of Spn43Ac function and confirm that suppression of insect immune system defenses represents a feasible approach to engineering entomopathogenic fungi for greater efficacy.
It is well known that interfacial structures and charge transfer in dye-sensitized solar cells are extremely important for the enhancement of cell efficiency. Here, the normal Raman spectra (NRS) and resonance Raman spectra (RRS) of a C343-sensitized TiO2 cluster (Ti9O18) are theoretically predicted from combined electronic structure calculations and a vibrationally-resolved spectral method to reveal the relationship between interfacial geometries and excited-state dynamics. The results show that although the NRS of free C343 and the C343-TiO2 cluster correspond to the vibrational motions of C343 in a high frequency domain, their mode frequencies show obvious differences due to the interaction of the TiO2 cluster on C343, and several new Raman active fingerprint modes, such as bidentate chelating bonding modes, can be used to determine interfacial geometries. However, the resonance Raman activities of low-frequency modes are significantly enhanced and several modes from the TiO2 cluster can be observed, consistent with experimental measurements. Furthermore, the RRS from a locally excited state and a charge transfer state of C343-TiO2 are dramatically different, for instance, new Raman active modes with 1212 cm(-1), 1560 cm(-1) and 1602 cm(-1), corresponding to the motions of CH2 rocking, C=C/C-N/C=O stretching and C=O/C=C stretching, appear from the charge transfer state. The obtained information on mode-specific reorganization energies from these excited states is greatly helpful to understand and control interfacial electron transfer.
Coinage metals, such as Cu, Ag and Au, can form nanoclusters, which, when functionalized with ligands, have unique electronic and optical properties and are widely used in biomedical imaging, remote sensing, labeling, catalytic, etc. The mechanisms, structures and properties of nanocluster assemblies have been well reviewed. However, the collections and analyses of nanocluster assemblies for sensor application are few. This review examines different nanocluster sensor platforms with a focus on the assembly and analysis of the assembly processes and examples of applications.
BackgroundCongenital tuberculosis is becoming increasingly common, but congenital tuberculosis infection in neonates following in vitro fertilization and embryo transfer (IVF-ET) has been rarely reported; a diagnosis of congenital tuberculosis is often delayed due to the non-specificity of maternal IVF treatments and clinical manifestations during pregnancy—particularly in low-birth-weight preterm infants.Case presentationWe herein report a case of congenital tuberculosis. The infant was born at 27+5 weeks of gestation and was admitted to the hospital due to hypopnea after birth. Due to a poor response to treatment, we conducted pathogenic microorganism metagenomic analysis to assess the nucleotide sequences within the Mycobacterium tuberculosis complex. After collecting sputum, the strains from the tuberculosis analysis were isolated and confirmed. From a detailed examination of the mother and in accordance with the child's congenital tuberculosis, we confirmed the diagnosis of pelvic tuberculosis.ConclusionIVF treatment and pregnancy can exacerbate latent tuberculosis, especially in women from a family with a history of tuberculosis infections. We posit that the optimal way to prevent neonatal congenital tuberculosis in IVF-ET is to procure a detailed maternal medical or family history and to identify and treat maternal tuberculosis during IVF treatment.
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