Ballistic-resistant stainless steel mesh compound nonwoven fabric

The energy of impact must decay and be transmitted after a bullet is shot through a ballistic-resistant cloth with a laminate structure. A rigid net structure transmits the impact stress to reduce the breakage of the material in the direction perpendicular to the fabric after the impacting of a projectile. This work combines the rigid net structure of stainless steel mesh with two layers a needle-punched polyamide nonwoven fabric to create a sandwich-like laminate structure. A compound fabric that is composed of a stainless steel mesh and polyamide nonwoven fabrics is placed in multi-layer Kevlar fabrics, and the buffer effect is measured by performing a dropping weight impact test and a bullet-shooting test. The specifications of the stainless steel mesh and the order of placement of the compound fabrics are varied to show the effect of these parameters on the energy of fracture propagation and the buffer effect of the multi-layered Kevlar compound fabric that includes a layer of compound fabric that is made of stainless steel mesh and polyamide nonwoven fabrics. In this study, the compound fabric replaces several layers of Kevlar unidirectional fabric, to be used to reduce the cost of bulletproof vests without reducing ballistic resistance.     

Integrated Omics Strategy Reveals Cyclic Lipopeptides Empedopeptins from Massilia sp. YMA4 and Their Biosynthetic Pathway

Empedopeptins—eight amino acid cyclic lipopeptides—are calcium-dependent antibiotics that act against Gram-positive bacteria such as Staphylococcus aureus by inhibiting cell wall biosynthesis. However, to date, the biosynthetic mechanism of the empedopeptins has not been well identified. Through comparative genomics and metabolomics analysis, we identified empedopeptin and its new analogs from a marine bacterium, Massilia sp. YMA4. We then unveiled the empedopeptin biosynthetic gene cluster. The core nonribosomal peptide gene null-mutant strains (ΔempC, ΔempD, and ΔempE) could not produce empedopeptin, while dioxygenase gene null-mutant strains (ΔempA and ΔempB) produced several unique empedopeptin analogs. However, the antibiotic activity of ΔempA and ΔempB was significantly reduced compared with the wild-type, demonstrating that the hydroxylated amino acid residues of empedopeptin and its analogs are important to their antibiotic activity. Furthermore, we found seven bacterial strains that could produce empedopeptin-like cyclic lipopeptides using a genome mining approach. In summary, this study demonstrated that an integrated omics strategy can facilitate the discovery of potential bioactive metabolites from microbial sources without further isolation and purification.     

Degradation of ioxynil by a soil fungus, Fusarium solani

A fungus, Fusarium solani, isolated from the soil, degraded ioxynil (3,5-diiodo-4-hydroxyben-zonitrile) in pure culture into at least eight products. Five products were detected in the organic fractions extracted from a culture grown in [¹⁴C]cyano-labeled ioxynil. Three additional products were separated by ion-exchange chromatography of the acidified aqueous phase. Cultures grown in the presence of [¹⁴C]ring-labeled ioxynil produced the same products in the organic extract and four to five products in the aqueous phase. The cyano-carbon of ioxynil was released as CO₂ at a faster rate than that of ring-carbons and was released after the initial ring cleavage. Two of the metabolites were identified as 3,5-diiodo-4-hydroxybenzamide and 3,5-diiodo-4-hydroxybenzoic acid.     

Association of the HL-A7 cross-reacting group with a specific reaginic antibody response in allergic man

A relatively small proportion (17 percent) of individuals highly allergic to ragweed were found to develop marked reaginic (immunoglobulin E-mediated) skin sensitivity to a minor ragweed pollen allergen Ra5 (molecular weight 5200). Sensitivity to Ra5 was significantly associated with the possession of a major histocompatibility antigen of the HL-A7 cross-reacting group. This appears to be the first evidence of a strong association between a specific immune response and a specific group of closely related HL-A antigens in man.     

Magnetoreception in honeybees

Magnetoreception by honeybees (Apis mellifera) is demonstrated by such activities as comb building and homing orientation, which are affected by the geomagnetic field. In other magnetoreceptive species, iron oxide crystals in the form of magnetite have been shown to be necessary for primary detection of magnetic fields. Here it is shown that trophocytes, which are apparently the only iron granule-containing cells in honeybees, contain super-paramagnetic magnetite. These cells are innervated by the nervous system, which suggests that trophocytes might be primarily responsible for magnetoreception. Electron microscopy also shows cytoskeletal attachments to the iron granule membrane.     

Forming electrical networks in three dimensions by self-assembly

Self-assembly of millimeter-scale polyhedra, with surfaces patterned with solder dots, wires, and light-emitting diodes, generated electrically functional, three-dimensional networks. The patterns of dots and wires controlled the structure of the networks formed; both parallel and serial connections were generated.     

Angiotensins stimulate in vitro ovulation and contraction of brook trout (Salvelinus fontinalis) follicles

The effects of salmon angiotensin I (sAI) and human angiotensin II (hAII) on in vitro ovulation of preovulatory (preOV) brook trout (Salvelinus fontinalis) follicles were investigated. Both angiotensins increased levels of ovulation above that in controls after 12 hours of incubation. The increase was statistically significant in incubates with greater than 1 M hAII. The effects of the angiotensins on follicle contraction were also studied indirectly by measuring the decrease in weight of punctured follicles taken prior to germinal vesicle breakdown. At 1 M, both angiotensins significantly decreased the weight of punctured follicles after 16 hours of incubation. The angiotensin-stimulated decrease in weight was not blocked by indomethacin (10 g/ml), indicating that follicle contraction was not prostaglandin-dependent. The data indicate that angiotensins might be directly involved in brook trout ovulation and the stimulatory effects of angiotensins on ovulation may be attributed to their effects on follicle contraction.This work was supported by NIH grant #HD25924-02.