Root orientation can affect detection accuracy of ground-penetrating radar

Aim

Ground-penetrating radar (GPR) has been applied to detect coarse tree roots. The horizontal angle of a root crossing a scanning line is a factor that affects both root detection and waveform parameter values. The purpose of this study was to quantitatively evaluate the influence of root orientation (x, degree) on two major waveform parameters, amplitude area (A, dB × ns) and time interval between zero crossings (T, ns).

Methods

We scanned four diameter classes of dowels in a sandy bed as simulated roots using a 900 MHz antenna from multiple angles to clarify the relationships between the parameters and x.

Results

Angle x strongly affected reflection images and A values. The variation in A(x) fitted a sinusoidal waveform, whereas T was independent of x. The value of A scanning at 90° was estimated by A values of arbitrary x in two orthogonal transects. The sum of T in all reflected waveforms showed a significant linear correlation with dowel diameter.

Conclusions

We clarified that root orientation dramatically affected root detection and A values. The sum of T of all reflected waveforms was a suitable parameter for estimating root diameter. Applying grid transects can overcome the effects of root orientation.     

Association analysis of the HLA-C gene in Japanese alopecia areata

Alopecia areata (AA) is an organ-specific and cell-mediated autoimmune disease involving hair loss, but its pathogenesis remains poorly understood. Many autoimmune diseases are genetically associated with alleles of the human leukocyte antigen (HLA) genes within the major histocompatibility complex. Associations between AA and HLA genes were previously observed in some different ethnic groups. However, the results were inconsistent, and a primary susceptibility HLA gene and/or region has not yet been assigned for AA. The aim of this study was to evaluate whether an allele of the HLA-C locus, HLA-C*07:04, which was strongly associated with AA in Chinese Hans, could be replicated in the Japanese population. The HLA-C locus was genotyped by the SSO method using 156 AA patients and 560 healthy controls. As a consequence, among the 17 alleles detected, only two alleles, C*04:01 (OR?=?2.25, CI 95 %?=?1.35–3.75, P?=?1.84E-03) and C*15:02 (OR?=?2.52, CI 95 %?=?1.37–4.64, P?=?2.90E-03), were significantly associated with AA after Bonferroni correction. Further, the stratification analysis suggested that C*04:01, C*07:02, and C*15:02 represented different AA genetic risk factors in each sub-phenotype.     

Adipose‐derived mesenchymal stem cells and regenerative medicine

Adipose tissue‐derived mesenchymal stem cells (ADSCs) are multipotent and can differentiate into various cell types, including osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β‐cells, and hepatocytes. Compared with the extraction of other stem cells such as bone marrow‐derived mesenchymal stem cells (BMSCs), that of ADSCs requires minimally invasive techniques. In the field of regenerative medicine, the use of autologous cells is preferable to embryonic stem cells or induced pluripotent stem cells. Therefore, ADSCs are a useful resource for drug screening and regenerative medicine. Here we present the methods and mechanisms underlying the induction of multilineage cells from ADSCs.     

Electrophysiological Characterization of the Mechanosensitive Channel MscCG in Corynebacterium glutamicum

Corynebacterium glutamicum MscCG, also referred to as NCgl1221, exports glutamate when biotin is limited in the culture medium. MscCG is a homolog of Escherichia coli MscS, which serves as an osmotic safety valve in E. coli cells. Patch-clamp experiments using heterogeneously expressed MscCG have shown that MscCG is a mechanosensitive channel gated by membrane stretch. Although the association of glutamate secretion with the mechanosensitive gating has been suggested, the electrophysiological characteristics of MscCG have not been well established. In this study, we analyzed the mechanosensitive gating properties of MscCG by expressing it in E. coli spheroplasts. MscCG is permeable to glutamate, but is also permeable to chloride and potassium. The tension at the midpoint of activation is 6.68 ± 0.63 mN/m, which is close to that of MscS. The opening rates at saturating tensions and closing rates at zero tension were at least one order of magnitude slower than those observed for MscS. This slow kinetics produced strong opening-closing hysteresis in response to triangular pressure ramps. Whereas MscS is inactivated under sustained stimulus, MscCG does not undergo inactivation. These results suggest that the mechanosensitive gating properties of MscCG are not suitable for the response to abrupt and harmful changes, such as osmotic downshock, but are tuned to execute slower processes, such as glutamate export.     

γ-Cyclodextrin–polyurethane copolymer adsorbent for selective removal of endotoxin from DNA solution

Copolymer particles for removal of endotoxins (lipopolysaccharides, LPSs) were prepared by suspension copolymerization of γ-cyclodextrin (CyD) and 1,6-hexamethylenediisocyanate. The LPS-removing activity of the copolymer particles was compared with that of poly(ε-lysine)-immobilized Cellufine (cationic adsorbent) or polystyrene particles (hydrophobic adsorbent) by a batch method. When DNA was present in solution with LPSs under physiological conditions (pH 6.0, ionic strength of μ = 0.05–0.8), LPS-removing activity of the cationic or hydrophobic adsorbent was unsatisfactory because both the DNA and the LPSs were adsorbed onto each adsorbent. By contrast, the copolymer particles with γ-CyD cavity (CyD content: 14–20 mol%) could selectively remove LPSs from a DNA solution (50 μg ml⁻¹, pH 6.0, and μ = 0.05–0.2) containing LPSs (15 EU ml⁻¹) without the adsorption of DNA. The residual concentration of LPSs in the treated DNA solution was below 0.1 EU ml⁻¹, and the recovery of DNA was 99%.     

Synthesis and biological evaluation of new chlorin derivatives as potential photosensitizers for photodynamic therapy

Three new water-soluble chlorin derivatives 3, 5 and 8 for potential use as photosensitizers in photodynamic therapy (PDT) for cancer were synthesized from photoprotoporphyrin IX dimethyl ester (1). The in vivo biodistribution and clearance of chlorin derivatives 3, 5 and 8 were investigated in tumor-bearing mice. Iminodiacetic acid derivative 8 showed the greatest tumor-selective accumulation among the new chlorin derivatives with maximum accumulation in tumor tissue at 3 h after intravenous injection and rapid clearance from normal tissues within 24 h after injection. The in vivo therapeutic efficacy of PDT using 8 was evaluated by measuring tumor growth rates in tumor-bearing mice with 660 nm light-emitting diode irradiation at 3 h after injection of 8. Tumor growth was significantly inhibited by PDT using 8. These results indicate that iminodiacetic acid derivative 8 is useful as a new photosensitizer to overcome the disadvantages of photosensitizers that are currently in clinical use.     

Structures of Ezomycins A1 and A2

The structures of ezomycins A₁. and A₂, antifungal antibiotics produced by a strain of Streptomyces, were determined as 1 and 2, respectively, by degradative and spectrometric studies.