Multicompartment Tubular Micromotors Toward Enhanced Localized Active Delivery

A tubular micromotor with spatially resolved compartments is presented toward efficient site-specific cargo delivery, with a back-end zinc (Zn) propellant engine segment and an upfront cargo-loaded gelatin segment further protected by a pH-responsive cap. The multicompartment micromotors display strong gastric-powered propulsion with tunable lifetime depending on the Zn segment length. Such propulsion significantly enhances the motor distribution and retention in the gastric tissues, by pushing and impinging the front-end cargo segment onto the stomach wall. Once the micromotor penetrates the gastric mucosa (pH ≥ 6.0), its pH-responsive cap dissolves, promoting the autonomous localized cargo release. The fabrication process, physicochemical properties, and propulsion behavior are systematically tested and discussed. Using a mouse model, the multicompartment motors, loaded with a model cargo, demonstrate a homogeneous cargo distribution along with approximately four-fold enhanced retention in the gastric lining compared to monocompartment motors, while showing no apparent toxicity. Therapeutic payloads can also be loaded into the pH-responsive cap, in addition to the gelatin-based compartment, leading to concurrent delivery and sequential release of dual cargos toward combinatorial therapy. Overall, this multicompartment micromotor system provides unique features and advantages that will further advance the development of synthetic micromotors for active transport and localized delivery of biomedical cargos.     

Raman and infrared fingerprint spectroscopy of peroxide-based explosives

A comparative study of the vibrational spectroscopy of peroxide-based explosives is presented. Triacetone triperoxide (TATP) and hexamethyl-enetriperoxide-diamine (HMTD), now commonly used by terrorists, are examined as well as other peroxide-ring structures: DADP (diacetone diperoxide); TPTP [3,3,6,6,9,9-Hexaethyl-1,2,4,5,7,8-hexaoxo-nonane (tripentanone triperoxide)]; DCypDp {6,7,13,14-Tetraoxadispiro [4.2.4.2]tetradecane (dicyclopentanone diperoxide)}; TCypDp {6,7,15,16,22,23-Hexaoxatrispiro[4.2.4.2.4.2] henicosane (tricyclopentanone triperoxide)}; DCyhDp {7,8,15,16-tetraoxadispiro [5.2.5.2] hexadecane (dicyclohexanone diperoxide)}; and TCyhTp {7,8,14,15,21,22-hexaoxatrispiro [5.2.5.2.5.2] tetracosane (tricyclohexanone triperoxide)}. Both Raman and infrared (IR) spectra were measured and compared to theoretical calculations. The calculated spectra were obtained by calculation of the harmonic frequencies of the studied compounds, at the density functional theory (DFT) B3LYP/cc-pVDZ level of theory, and by the use of scaling factors. It is found that the vibrational features related to the peroxide bonds are strongly mixed. As a result, the spectrum is congested and highly sensitive to minor changes in the molecule.     

Nanoparticulate Delivery of Cancer Cell Membrane Elicits Multiantigenic Antitumor Immunity

Anticancer vaccines train the body's own immune system to recognize and eliminate malignant cells based on differential antigen expression. While conceptually attractive, clinical efficacy is lacking given several key challenges stemming from the similarities between cancerous and healthy tissue. Ideally, an effective vaccine formulation would deliver multiple tumor antigens in a fashion that potently stimulates endogenous immune responses against those antigens. Here, it is reported on the fabrication of a biomimetic, nanoparticulate anticancer vaccine that is capable of delivering autologously derived tumor antigen material together with a highly immunostimulatory adjuvant. The two major components, tumor antigens and adjuvant, are presented concurrently in a fashion that maximizes their ability to promote effective antigen presentation and activation of downstream immune processes. Ultimately, it is demonstrated that the formulation can elicit potent antitumor immune responses in vivo. When combined with additional immunotherapies such as checkpoint blockades, the nanovaccine demonstrates substantial therapeutic effect. Overall, the work represents the rational application of nanotechnology for immunoengineering and can provide a blueprint for the future development of personalized, autologous anticancer vaccines with broad applicability.     

Selective attention and control of action: Comparative psychology of an artificial, evolved agent and people.

This study examined the selective attention abilities of a simple, artificial, evolved agent and considered implications of the agent's performance for theories of selective attention and action. The agent processed two targets in continuous time, catching one and then the other. This task required many cognitive operations, including prioritizing the first target (T1) over the second (T2); selectively focusing responses on T1, while preventing T2 from interfering with responses; creating a memory for the unselected T2 item, so that it could be efficiently processed later; and reallocating processing towards T2 after catching T1. The evolved agent demonstrated all these abilities. Analysis shows that the agent used reactive inhibition to selectively focus behavior. That is, the more salient T2, the more strongly responses towards T2 were inhibited and the slower the agent was to subsequently reallocate processing towards T2. Reactive inhibition was also suggested in two experiments with people, performing a virtually identical catch task. The presence of reactive inhibition in the simple agent and in people suggests that it is an important mechanism for selective processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Job stress in midlife working women: Relationships among personality type, job characteristics, and job tension.

Investigated the relationships among midlife working women's Type A (coronary prone) personality, perceived job characteristics, and feelings of job tension. The Women's Work Questionnaire was administered to 161 35–55 yr old females who were employed by a large state social service agency. The questionnaire, developed for the present study, comprises sections for demographic and job-related information, the Sales Type A Personality Index—Short Form, the Job Characteristics Inventory, and the Job-Related Tension Index. Multiple regression analyses revealed a significant relationship between job tension and a linear combination of Type A personality and job characteristics (i.e., autonomy, feedback, significance, friendship opportunities, variety, challenge, identity, dealing with others). There were also significant relationships between job tension and the following variables considered singularly: Type A personality, autonomy, feedback, significance, and friendship opportunities. Results support a person–environment fit approach to the study, prevention, and remediation of job stress. (80 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of dentate gyrus cells in retention of a radial arm maze task and sensitivity of rats to cholinergic drugs.

Male rats that received bilateral injections of colchicine into 2 rostrocaudal sites showed relatively long-lasting alterations in a previously acquired radial arm maze task and specific destruction of dentate granule cells. Subsequent experiments with cholinergic drugs indicate that physostigmine or nicotine had no effect on number of errors made in the maze, although other signs of cholinergic or pharmacological activity were present. RS-86, an analog of arecoline, decreased errors in colchicine-treated Ss, but effects were associated with signs of parasympathetic overstimulation and behavioral sedation. Pretreatment with scopolamine increased errors in controls but had no effect in colchicine-treated Ss. Colchicine-treated Ss were less sensitive to the motor stimulant effect of scopolamine. Effects appeared to be associated with increased levels of choline acetyltransferase in the hippocampus and a down regulation of muscarinic postsynaptic receptors. Intradentate colchicine may destroy granule cells, leading to compensatory reinnervation of cholinergic nerve terminals having cell bodies in the septum. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of the 15?N gas flux method to measure the source and level of N2O and N2 emissions from grazed grassland

Understanding the contribution of nitrification and denitrification to production of nitrous oxide (N₂O), a potent greenhouse gas, is important in devising effective mitigation strategies to reduce emissions. In this study the ¹⁵N gas flux method was used to investigate N₂O and N₂ emissions following an application of ¹⁵N labelled ammonium nitrate (0.71?mol?N?m^?2) to intensive grassland swards (grazed at 2.74 or 2.05 livestock units ha^?1 year^?1) at a site in Southern Ireland. The ¹⁵N labelled fertiliser (NO₃ moiety ¹⁵N labelled at 60 at. %) was applied to designated soil areas in the field, enclosed by static chambers, in June 2009, September 2009 and March 2010. Fluxes of N₂O and N₂ were determined over 12?days on each occasion. N₂O and N₂ emissions were significantly (P?<?0.001) lower in March 2010 than in June or September 2009. There was little difference between the two swards grazed at different stocking rates on N₂O or N₂ emissions. Mean cumulative N₂O emissions over 103?h were 212.9, 279.5 and 62.06?mg?m^?2 for June 2009, September 2009 and March 2010, respectively. Mean cumulative N₂ emissions for the three time periods were 818.8, 893.8 and 87?mg?m^?2, respectively. The N₂O mole fraction averaged 0.21 and 0.23 in June 2009 and September 2009, respectively, but increased to 0.41 in March 2010 which may have been due to changes in denitrifier community composition or due to N₂O reductase being sensitive to low soil temperatures. The results point to denitrification of nitrate as the major source of N₂O at this site which may have implications for choice of fertiliser in moist temperate climates.     

International harmonization of grid connection guidelines: adequate requirements for the prevention of unintentional islanding

Islanding is still one of the major controversial subjects in the international harmonization of grid connection requirements for distributed generation, and particularly photovoltaics. As long as islanding is not intended in order to back up a loss of mains, it should be avoided. The present study reviews the theory of unintentional islanding and assesses the probability of occurrence of the phenomenon, based on previous studies and theoretical considerations. While islanding is virtually impossible if only a small number of distributed generation units is connected to a distribution grid, with higher distributed generation densities, the possibility of islanding becomes realistic. The risk associated with unintentional islanding is estimated, and adequate requirements for functional safety of protection devices are determined in order to ensure the necessary additional degree of safety to be introduced by an islanding prevention device. Finally, a fundamental set of requirements with regard to islanding, to be included in an international grid connection guideline, is derived from the study. Copyright © 2003 John Wiley & Sons, Ltd.     

Well-functioning balancing markets: A prerequisite for wind power integration

This article focuses on the design of balancing markets in Europe taking into account an increasing wind power penetration. In several European countries, wind generation is so far not burdened with full balancing responsibility. However, the more wind power penetration, the less bearable for the system not to allocate balancing costs to the responsible parties. Given the variability and limited predictability of wind generation, full balancing exposure is however only feasible conditionally to well-functioning balancing markets. On that account, recommendations ensuring an optimal balancing market design are formulated and their impact on wind generation is assessed. Taking market-based or cost-reflective imbalance prices as the main objective, it is advised that: (1) the imbalance settlement should not contain penalties or power exchange prices, (2) capacity payments should be allocated to imbalanced BRPs via an additive component in the imbalance price and (3) a cap should be imposed on the amount of reserves. Efficient implementation of the proposed market design may require balancing markets being integrated across borders.     

Velocity Distributions after Laser-Induced Desorption of NO from NiO(100)—The Role of the Angular Coordinate

The experimental velocity distributions of NO desorbing from a NiO(100)-surface are simulated using a time-dependent wave packet method. Including the polar angle between the surface normal and the adsorbate molecular axis yields bimodal distributions in the correct velocity range and reasonable desorption probabilities if a resonance lifetime on the order of 25 fs is assumed. For two-dimensional simulations, an angular-independent charge-transfer-state was chosen as excited state in order to investigate the influence of the electronic ground-state on the final state distributions. We compare our results with wave packet calculations using a representative ab initio angular-dependent excited-state potential energy surface using a three-dimensional Hamiltonian.