Ring-Fluorinated Analog of Methyl Eugenol: Attractiveness to and Metabolism in the Oriental Fruit Fly, <Emphasis Type="Italic">Bactrocera Dorsalis</Emphasis> (Hendel)

Oriental fruit fly, Bactrocera dorsalis (Hendel), males are highly attracted to the natural phenylpropanoid methyl eugenol (ME). They compulsively feed on ME and metabolize it to ring and side-chain hydroxylated compounds that have both pheromonal and allomonal functions. Side-chain metabolic activation of ME leading to (E)-coniferyl alcohol has long been recognized as a primary reason for hepatocarcinogenicity of this compound in rodents. Earlier, we demonstrated that introduction of a fluorine atom at the terminal carbon of the ME side chain significantly depressed metabolism and specifically reduced formation of coniferyl alcohol but had little effect on field attractiveness to B. dorsalis. In the current paper, we demonstrate that fluorination of ME at the 4 position of the aromatic ring blocks metabolic ring-hydroxylation but overall enhances side-chain metabolism by increasing production of fluorinated (E)-coniferyl alcohol. In laboratory experiments, oriental fruit fly males were attracted to and readily consumed 1,2-dimethoxy-4-fluoro-5-(2-propenyl)benzene (I) at rates similar to ME but metabolized it faster. Flies that consumed the fluorine analog were as healthy post feeding as ones fed on methyl eugenol. In field trials, the fluorine analog I was ∼50% less attractive to male B. dorsalis than ME.

A Dual Physical Cross-Linking Strategy to Construct Tough Hydrogels with High Strength,Excellent Fatigue Resistance,and Stretching-Induced Strengthening Effect

Hydrogels with excellent stiffness, toughness, anti-fatigue, and self-recovery properties are regarded as promising water-containing materials. In this work, a dual physically cross-linked (DPC) sodium alginate (SA)/poly[acrylamide (AAm)-acrylic acid (AAc)-octadecyl methacrylate (OMA)]-Fe³⁺ hydrogel is reported, which is constructed by hydrophobic association (HA) and ionic coordination (IC). The optimal DPC hydrogel demonstrates excellent mechanical performance: tensile modulus of 0.65 MPa, tensile strength of 3.31 MPa, elongation at break of 1547%, and toughness of 27.8 MJ m^–3. SA/P(AAm-AAc-OMA)-Fe³⁺ DPC hydrogels also exhibit prominent anti-fatigue and self-recovery performance (99.1–109.7% modulus recovery and 90.4–108.9% dissipated energy recovery after resting for 5 min without additional stimuli at ambient temperature) through the reconstruction of reversible physical cross-linking. Some of the SA/P(AAm-AAc-OMA)-Fe³⁺ DPC hydrogels even exhibit a stretching-induced strengthening effect, which is similar to the performance of muscle—“the more training, the more strength.” Hence, the combination of HA and IC will provide an effective approach to design DPC hydrogels with desirable mechanical performances and a longer service life for wider applications of soft materials.     

Study of pressure and temperature developing profiles in crude oil pipe flows

Pressure and temperature developing profiles for crude oil transportation pipelines are simulated under a diversity of external boundary conditions. MOLCV is used in this research to convert a system of partial differential equations into a system of ordinary first order differential equations in cylindrical coordinates. Momentum and energy balance equations are coupled in crude oil flows because of thermal–physical property variations. Simulation solutions show the effect of boundary conditions in the pressure drop profile, which provide potential model predictive applications to account for weather forecast in crude oil transportation operations.     

Green Biocomposites for Thermoelectric Wearable Applications

The materials commonly used to fabricate thermoelectric devices are tellurium, lead, and germanium. These materials ensure the best thermoelectric performance, but exhibit drawbacks in terms of availability, sustainability, cost, and manufacturing complexity. Moreover, they do not guarantee a safe and cheap implementation in wearable thermoelectric applications. Here, p‐Type and n‐type flexible thermoelectric textiles are produced with sustainable and low‐cost materials through green and scalable processes. Cotton is functionalized with inks made with biopolyester and carbon nanomaterials. Depending on the nanofiller, i.e., graphene nanoplatelets, carbon nanotubes, or carbon nanofibers, positive or negative Seebeck coefficient values are obtained, resulting in a remarkable electrical conductivity value of 55 S cm^?1 using carbon nanotubes. The best bending and washing stability are registered for the carbon nanofiber‐based biocomposites, which increase their electrical resistance by 5 times after repeated bending cycles and only by 30% after washing. Finally, in‐plane flexible thermoelectric generators coupling the best p‐ and n‐type materials are fabricated and analysed, resulting in an output voltage of ≈1.65 mV and a maximum output power of ≈1.0 nW by connecting only 2 p/n thermocouples at a temperature difference of 70 °C.     

GaAs-based modulation-doped quantum-well infrared photodetectors for single- and two-color detection in 3-5 /spl mu/m

Double-barrier quantum-well infrared photodetectors are promising for operation in the midinfrared region. In this paper, we present a series of novel molecular beam epitaxy (MBE)-grown devices based on modulation-doped (MD) AlGaAs-AlAs-GaAs structures that exhibit a remarkable responsivity at zero bias (0.05 A/W) at 4.6 /spl mu/m. Since the photovoltaic properties are strongly dependent on the symmetry of the potential profile, we have systematically varied the position of the dopant in the barriers for a series of single-color detectors. Low-temperature photocurrent spectra and current-voltage (I-V) characteristics (in the dark and under illumination) show that the location of the dopant is a relevant design parameter, due to its role in the photovoltaic behavior (i.e., the presence or absence of zero bias signal). The performance of the MD devices is compared with that of a detector with doping in the center of the well and otherwise the same structure. In particular, the responsivity and detectivity seem to be higher for the MD detectors than for well-doped samples, especially when the dopant is located in the barrier closest to the substrate. Therefore, we have chosen that MD dopant profile when designing and growing, to our knowledge, the first 3-5 /spl mu/m two-color detector, with simultaneous detection at 3.8 and 4.4 /spl mu/m.     

EDX analysis and microstructural properties of the Yba2Cu3O7−δ-Ba2HoSbO6 superconducting composites

We have fabricated and characterized Yba ₂ Cu ₃ O _7– -Ba ₂ HoSbO ₆ a realized high T _c superconductor - ceramic insulator composite system in which particles of the superconductor and ceramic insulator could coexist with well defined separated phases left intact by stringent processing conditions. All the composites exhibit superconductivity at 92K. EDX analysis show that element% and atomic% of the composites are in a good agreement with those of their respective components. SEM studies show homogenous surface morphology and particle size distribution. There is no detectable interface interaction between component grains and Ba ₂ HoSbO ₆ grains are distinguishably distributed in the Yba ₂ Cu ₃ O _7– matrix.     

The molecular structure of green fluorescent protein

The crystal structure of recombinant wild-type green fluorescent protein (GFP) has been solved to a resolution of 1.9 A by multiwavelength anomalous dispersion phasing methods. The protein is in the shape of a cylinder, comprising 11 strands of beta-sheet with an alpha-helix inside and short helical segments on the ends of the cylinder. This motif, with beta-structure on the outside and alpha-helix on the inside, represents a new protein fold, which we have named the beta-can. Two protomers pack closely together to form a dimer in the crystal. The fluorophores are protected inside the cylinders, and their structures are consistent with the formation of aromatic systems made up of Tyr66 with reduction of its C alpha-C beta bond coupled with cyclization of the neighboring glycine and serine residues. The environment inside the cylinder explains the effects of many existing mutants of GFP and suggests specific side chains that could be modified to change the spectral properties of GFP. Furthermore, the identification of the dimer contacts may allow mutagenic control of the state of assembly of the protein.     

A randomized phase-II study of BB-10010 (macrophage inflammatory protein- 1alpha) in patients with advanced breast cancer receiving 5-fluorouracil, adriamycin, and cyclophosphamide chemotherapy

BB-10010 is a variant of the human form of macrophage inflammatory protein-1alpha (MIP-1alpha), which has been shown in mice to block the entry of hematopoietic stem cells into S-phase and to increase their self-renewal capacity during recovery from cytotoxic damage. Its use may constitute a novel approach for protecting the quality of the stem cell population and its capacity to regenerate after periods of cytotoxic treatment. Thirty patients with locally advanced or metastatic breast cancer were entered into the first randomized, parallel group controlled phase II study. This was designed to evaluate the potential myeloprotective effects of a 7-day regimen of BB-10010 administered to patients receiving six cycles of 5-fluorouracil (5-FU), adriamycin, and cyclophosphamide (FAC) chemotherapy. Patients were randomized, 10 receiving 100 microgram/kg BB-10010, 11 receiving 30 microgram/kg BB-10010, and nine control patients receiving no BB-10010. BB-10010 was well-tolerated in all patients with no severe adverse events related to the drug. Episodes of febrile neutropenia complicated only 4% of the treatment cycles and there was no difference in incidence between the treated and nontreated groups. Studies to assess the generation of progenitor cells in long-term bone marrow cultures were performed immediately preceding chemotherapy and at the end of six dosing cycles in 18 patients. Circulating neutrophils, platelets, CD 34(+) cells, and granulocyte/macrophage colony-forming cell (GM-CFC) levels were determined at serial time points in cycles 1, 3, and 6. The results showed similar hemoglobin and platelet kinetics in all three groups. On completion of the six treatment cycles, the average pretreatment neutrophil levels were reduced from 5.3 to 1.7 x 10(9)/L in the control patients and from 4.3 to 1.9 and 4.5 to 2.5 x 10(9)/L in the 30/100 microgram/kg BB-10010 groups, respectively. Relative to their pretreatment values, 50% of the patients receiving BB-10010 completed the treatment with neutrophil values significantly higher than any of the controls (P = .02). Mobilization of GM-CFC was enhanced by BB-10010 with an additional fivefold increase over that generated by chemotherapy alone, giving a maximal 25-fold increase over pretreatment values. Bone marrow progenitor assays before and after this standard regimen of chemotherapy indicated little long-term cumulative impairment to recovery from chemotherapy. Despite the limited cumulative damage to the bone marrow, which may have minimized the protective value of BB-10010 during this regimen of chemotherapy, better recovery of neutrophils in the later treatment cycles with BB-10010 was indicated in a number of patients.