Transmission power requirements for novel ZigBee implants in the gastrointestinal tract

In this paper, a novel multinode wireless monitoring platform, based on ZigBee communication standard, is presented and tested in vivo. The transmission power levels needed to establish a reliable connection from the different gastrointestinal districts are reported and compared with safety levels from international guidelines. These findings can be useful to evaluate the effectiveness of a commercial and standardized approach to implantable and miniaturized monitoring of physiological parameters.     

A thermal monitoring sheet with low influence from adjacent waterbolus for tissue surface thermometry during clinical hyperthermia

This paper presents a complete thermal analysis of a novel conformal surface thermometer design with directional sensitivity for real-time temperature monitoring during hyperthermia treatments of large superficial cancer. The thermal monitoring sheet (TMS) discussed in this paper consists of a 2-D array of fiberoptic sensors embedded between two layers of flexible, low-loss, and thermally conductive printed circuit board (PCB) film. Heat transfer across all interfaces from the tissue surface through multiple layers of insulating dielectrics surrounding the small buried temperature sensor and into an adjacent temperature-regulated water coupling bolus was studied using 3-D thermal simulation software. Theoretical analyses were carried out to identify the most effective differential TMS probe configuration possible with commercially available flexible PCB materials and to compare their thermal responses with omnidirectional probes commonly used in clinical hyperthermia. A TMS sensor design that employs 0.0508-mm Kapton MTB and 0.2032-mm Kapton HN flexible polyimide films is proposed for tissue surface thermometry with low influence from the adjacent waterbolus. Comparison of the thermal simulations with clinical probes indicates the new differential TMS probe design to outperform in terms of both transient response and steady-state accuracy in selectively reading the tissue surface temperature, while decreasing the overall thermal barrier of the probe between the coupling waterbolus and tissue surface.      

Fabrication of a Macroporous Microwell Array for Surface‐Enhanced Raman Scattering

Here, a colloidal templating procedure for generating high‐density arrays of gold macroporous microwells, which act as discrete sites for surface‐enhanced Raman scattering (SERS), is reported. Development of such a novel array with discrete macroporous sites requires multiple fabrication steps. First, selective wet‐chemical etching of the distal face of a coherent optical fiber bundle produces a microwell array. The microwells are then selectively filled with a macroporous structure by electroless template synthesis using self‐assembled nanospheres. The fabricated arrays are structured at both the micrometer and nanometer scale on etched imaging bundles. Confocal Raman microscopy is used to detect a benzenethiol monolayer adsorbed on the macroporous gold and to map the spatial distribution of the SERS signal. The Raman enhancement factor of the modified wells is investigated and an average enhancement factor of 4 × 10⁴ is measured. This demonstrates that such nanostructured wells can enhance the local electromagnetic field and lead to a platform of ordered SERS‐active micrometer‐sized spots defined by the initial shape of the etched optical fibers. Since the fabrication steps keep the initial architecture of the optical fiber bundle, such ordered SERS‐active platforms fabricated onto an imaging waveguide open new applications in remote SERS imaging, plasmonic devices, and integrated electro‐optical sensor arrays.     

Theory and simulation of a thermally matched micromachined thermopile in a wearable energy harvester

In this paper, a new theoretical concept in the thermoelectric theory is discussed, which is important for design optimization of a thermoelectric energy harvester. The general conditions are defined, which are required to make a thermoelectric converter effective in energy harvester application. The necessity of the work has been prompted by the fact that while modeling the harvesters neither a constant temperature difference nor a constant heat flow can be assumed. It is shown that the proposed equations allow thermal optimization of energy harvesters to reach their top performance characteristics. The example of thermal optimization in case of MEMS thermopiles is discussed then. It is shown that the knowledge of thermal properties of the environment, i.e., those of a heat source and a heat sink, play the key role in the optimization procedure.     

“会跳”的空爆手榴弹

<正>德国的RWM公司正在完成为瑞典研制取代目前手榴弹的新型空爆手榴弹的工作。2010年2月,瑞典国防装备管理局将一项研制、鉴定和批量生产该手榴弹的合同授予RWM公司。鉴定工作预计2011年3月进行,首批交付工作预计2011年底     

Radiolabeled Polymeric Nanoconstructs Loaded with Docetaxel and Curcumin for Cancer Combinatorial Therapy and Nuclear Imaging

Growing evidence suggests that multifaceted diseases as cancer can be effectively tackled by hitting simultaneously different biological targets and monitoring patient‐specific responses. Combinatorial therapies, relying on the administration of two or more molecules with different cytotoxic mechanisms, are rapidly progressing in the clinic. Here, 100 nm spherical polymeric nanoconstructs (SPNs) are proposed for the combinatorial treatment of tumors by codelivering a potent antimitotic drug—docetaxel (DTXL)—and a broad spectrum anti‐inflammatory molecule—curcumin (CURC). In vitro, SPNs loaded with DTXL and CURC induce a threefold decrease in IC₅₀ as compared to DTXL‐loaded SPNs. This synergic antitumor effect is also significant in mouse models of glioblastoma multiforme, where, after 22 d of treatment, the combinatorial approach leads to complete disease regression. At 90 d post‐treatment initiation, mice injected with DTXL + CURC SPNs have a 100% survival, whereas only 50% of the DTXL SPN treated mice survive. SPNs are also labeled with radioactive ⁶⁴Cu(DOTA) molecules to document, via PET imaging, the progressive tumor mass shrinkage. Sensitization of DTXL by CURC is associated with NF‐κB downregulation and increased apoptosis. These theranostic nanoconstructs could be used for combinatorial treatment and assessment of therapeutic efficacy in other malignancies.     

Hierarchically Structured Magnetic Nanoconstructs with Enhanced Relaxivity and Cooperative Tumor Accumulation

Iron oxide nanoparticles are formidable multifunctional systems capable of contrast enhancement in magnetic resonance imaging, guidance under remote fields, heat generation, and biodegradation. Yet, this potential is underutilized in that each function manifests at different nanoparticle sizes. Here, sub‐micrometer discoidal magnetic nanoconstructs are realized by confining 5 nm ultra‐small super‐paramagnetic iron oxide nanoparticles (USPIOs) within two different mesoporous structures, made out of silicon and polymers. These nanoconstructs exhibit transversal relaxivities up to ≈10 times (r ₂ ≈ 835 mm ^?1 s^?1) higher than conventional USPIOs and, under external magnetic fields, collectively cooperate to amplify tumor accumulation. The boost in r ₂ relaxivity arises from the formation of mesoscopic USPIO clusters within the porous matrix, inducing a local reduction in water molecule mobility as demonstrated via molecular dynamics simulations. The cooperative accumulation under static magnetic field derives from the large amount of iron that can be loaded per nanoconstuct (up to ≈65 fg) and the consequential generation of significant inter‐particle magnetic dipole interactions. In tumor bearing mice, the silicon‐based nanoconstructs provide MRI contrast enhancement at much smaller doses of iron (≈0.5 mg of Fe kg^?1 animal) as compared to current practice.