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Background: Endovascular interventions in infrapopliteal occlusive artery disease are becoming more complex, and this frequently tests the standard method of treatment, plain old balloon angioplasty (POBA). The potential that serration angioplasty could produce a more acceptable tibial artery lumen was assessed in this study. Aim: The aim of this single-center subgroup analysis was to compare acute angiographic results after endovascular treatment using the Serranator serration balloon catheter in patients participating in the PRELUDE-BTK trial with POBA of the infrapopliteal arteries. A secondary objective was to assess post-treatment hemodynamic improvements. Methods: Our center enrolled 15 subjects and treated 17 lesions within the multicenter prospective core laboratory–adjudicated PRELUDE-BTK study. A 25 lesions analyzed separately were treated with POBA and then compared with the Serranator subset. In both cohorts, lesions were treated with either plain angioplasty or Serranator as a stand-alone therapy; subsequent methods, such as drug elution technologies, were not used. Acute angiographic results were analyzed by the SynvaCor angiographic core laboratory. To assess volumetric flow rates, data were analyzed with a fluid flow simulation software and compared against Poiseuille’s Law. Results: Final residual stenosis was 17.2%±8.2% in the Serranator group versus 33.7%±15.7% in the POBA group. The mean lumen diameter (MLD) gain for the Serranator group and the POBA group was 1.64±0.41 mm and 1.33±0.63 mm, respectively. The average atmospheric balloon inflation pressure was 5 ATM in the Serranator group versus 9 ATM in the POBA group. Neither group required a bailout stent; however, it was notable that there were significantly more chronic total occlusions (CTOs) treated in the Serranator group at 41.2% versus 12% in the POBA group. Regarding the effectiveness in improving hemodynamic blood flow for non-CTO lesions, the calculated average ratio of post-treatment to pre-treatment flow rates in the Serranator group was 238% than that for the POBA group. For CTO cases where pre-treatment flow rate was zero, final residual stenosis was used as the parameter for comparison. The Serranator group showed a 62% improvement in final residual stenosis over POBA. Conclusion: Endovascular treatment of the infrapopliteal arteries by use of the Serranator serration balloon provides a novel and promising method of action compared with standard balloon angioplasty and, thus, may have a leading role in complex below-the-knee arterial lesions. Clinical Impact The Serranator device might help to adequately address issues with conventional routine techniques for the treatment of complex lesions in infrapopliteal arteries in patients with advanced stages of PAD and critical limb ischemia. Integrating modern technologies such as the Serranator balloon catheter into clinical routine is mandatory in order to gain a more favorable outcome in these severely diseased patients and, particularly, to reduce mortality and morbidity.

Author(s): Chen, Yongtai; Tang, William C; Chu, Jinkui; Zhang, Ran; Li, Song | Abstract: An accurate sky polarization field map is a prerequisite for polarization navigation applications. In this article, a detector for sky full-polarization imaging detection is described, the major error-influencing factors (MEIFS ) are obtained, and the error propagation is modeled and analyzed. We reveal the relationship between the error of the inversed Stokes vector and the condition number of the detector matrix, which shows that the error of the inversed Stokes vector is affected by the Stokes vector of the incident light itself and the MEIFS together, with the MEIFS playing a decisive role. With the MEIFS optimized, the impact of detector error on the inversed Stokes vector is attenuated. A control equation for system calibration is also deduced which can establish the connection between the detector matrix design and calibration process. The work in this article provides a reference for optimization and calibration of sky full-polarization imaging detectors.

Author(s): Zhang, S; Guo, X; Jin, Z; Kang, R; Guo, D; Tang, WC | Abstract: Machining surface topography is a key factor affecting the properties of optical materials.It is generally accepted that the fracture mode tends to dominate practical concerns onmachined parts and the elastic recovery area decreases with the increase of normal load.However, material removal rate is low for ductile zone processing of brittle materials. In thiscase, pile-up and elastic recovery are key factors for surface quality. In this study, an accuratescratching and ploughing hardness model with consideration of both pile-up and elasticrecovery was established based on a series of continuous and constant nanoscratch tests.The hardness evolution mechanism under different nanoscratch deformation modes wasthen investigated. It was found that, in different modes, hardness values exhibited differentcharacteristics due to the change of elastic recovery rate and the intersection of elastic andplastic states. Further, the mapping relationship between hardness dispersion and surfacemorphology characteristics was also investigated. The results indicated that high degree ofhardness dispersion usually corresponded to modes I and II while stable hardness valuerepresented a steady plastic stage. Based on the intrinsic relationship between evolution ofhardness and deformation modes, predicting hardness distribution by in-situ testing dataand then adjusting deformation mode in real time would be helpful in optimizing surfacequality.

Mueller matrix imaging polarimetry (MMIP) is a promising technique for the textural characterization of biological tissue structures. To reveal the influence of imaging magnification on the robustness of Mueller matrix parameters (MMPs), the spatial scale stability of MMPs was studied. We established a new MMIP detector and derived the mathematical model of the spatial scale stability of MMPs. The biological tissues with well-defined structural components were imaged under different magnifications. Then, we compared and analyzed the textural features of the MMPs in the resulting images. The experimental results match the predictions of the mathematical model in these aspects: (i) magnification exhibits a strong nonlinear effect on the textural contrasts of MMPs images; (ii) higher magnification does not necessarily lead to superior contrast for textural characterization; and (iii) for different biological tissues, MMPs contrasts can be optimized differently, with some showing superior results. This study provides a reference for the experimental design and operation of the MMIP technique and is helpful for improving the characterization ability of MMPs. This article is protected by copyright. All rights reserved.

Retinal degeneration is a leading cause of vision impairment and blindness worldwide and medical care for advanced disease does not exist. Stem cell-derived retinal organoids (RtOgs) became an emerging tool for tissue replacement therapy. However, existing RtOg production methods are highly heterogeneous. Controlled and predictable methodology and tools are needed to standardize RtOg production and maintenance. In this study, we designed a shear stress-free micro-millifluidic bioreactor for nearly labor-free retinal organoid maintenance. We used a stereolithography (SLA) 3D printer to fabricate a mold from which Polydimethylsiloxane (PDMS) was cast. We optimized the chip design using in silico simulations and in vitro evaluation to optimize mass transfer efficiency and concentration uniformity in each culture chamber. We successfully cultured RtOgs at three different differentiation stages (day 41, 88, and 128) on an optimized bioreactor chip for more than 1 month. We used different quantitative and qualitative techniques to fully characterize the RtOgs produced by static dish culture and bioreactor culture methods. By analyzing the results from phase contrast microscopy, single-cell RNA sequencing (scRNA seq), quantitative polymerase chain reaction (qPCR), immunohistology, and electron microscopy, we found that bioreactor-cultured RtOgs developed cell types and morphology comparable to static cultured ones and exhibited similar retinal genes expression levels. We also evaluated the metabolic activity of RtOgs in both groups using fluorescence lifetime imaging (FLIM), and found that the outer surface region of bioreactor cultured RtOgs had a comparable free/bound NADH ratio and overall lower long lifetime species (LLS) ratio than static cultured RtOgs during imaging. To summarize, we validated an automated micro-millifluidic device with significantly reduced shear stress to produce RtOgs of comparable quality to those maintained in conventional static culture.

Temperature of sporophylls from excised male cones of three species from the Zamiaceae family (Ceratozamia miqueliana, Zamia fairchildiana, and Zamia pumila) and from one species from the Cycadaceae family (Cycas siamensis) was recorded over several days in an environmental chamber. Each species exhibited a different temperature profile. C. miqueliana and Z. fairchildiana were highly thermogenic, whereas C. siamensis and Z. pumila were weakly thermogenic. In C. miqueliana, the temperature of one sporophyll rose to 10 °C above ambient while other sporophylls on the same cone only reached temperatures of 0–3 °C above ambient. Temperature rates among the different cones varied between ≈ 0.01 and 0.09 ∆ °C/h. Temperature profiles of sporophylls of Z. fairchildiana and C. siamensis were reported for the first time. Studies of thermogenesis of single sporophylls in a controlled environment provide accurate temperature measurements. Furthermore, sporophylls can be exposed to different environments and thus improve our understanding of the mechanism of thermogenesis in vivo.

Retinal degeneration is a leading cause of vision impairment and blindness worldwide and medical care for advanced disease does not exist. Stem cell-derived retinal organoids (RtOgs) became an emerging tool for tissue replacement therapy. However, existing RtOg production methods are highly heterogeneous. Controlled and predictable methodology and tools are needed to standardize RtOg production and maintenance. In this study, we designed a shear stress-free micro-millifluidic bioreactor. We used a stereolithography (SLA) 3D printer to fabricate a mold from which Polydimethylsiloxane (PDMS) was cast. The multi-chamber bioreactor design and fabrications methods easily combined micro and millimeter features with very low cost and short manufacturing time. We optimized the chip design using in silico simulations and in vitro evaluation to optimize mass transfer efficiency and concentration uniformity in each culture chamber. We successfully cultured RtOgs on an optimized bioreactor chip for 37 days. We also characterized the RtOgs produced by static dish culture and chip culture methods using qualitative and quantitative techniques. Phase contrast imaging showed that both conventional and chip-cultured RtOgs developed a transparent outermost surface structure. Fluorescence lifetime imaging (FLIM) showed that RtOgs on the chip had significantly lower long lifetime species (LLS) ratio than static cultured ones, which demonstrated that bioreactor cultured RtOgs exhibited less oxidative stress. RtOgs in bioreactor culture demonstrated higher NADH signal overall, but both bioreactor and conventional cultures showed similar free/bound NADH ratio over time, which indicated normal differentiation time course. RtOg gene expression was examined by fluorescence imaging and quantitative polymerase chain reaction (qPCR) analyses. RtOgs in both groups showed thick nuclear outer layers expressing CRX on day 120 of differentiation. The gene profiling showed both groups expressed retinal progenitor genes and most of the tested photoreceptor markers. We, therefore, validated an autonomous micro-millifluidic device with significantly reduced shear stress and lower oxidative stress to produce RtOgs of equal or greater quality than those maintained in conventional static culture.

Most cycads have intimate associations with their insect pollinators that parallel those of well-known flowering plants, such as sexually deceptive orchids and the male wasps and bees they deceive. Despite this, the mistaken belief that cycads are mostly wind-pollinated is still commonly expressed. Perhaps as a consequence, cycad–pollinator systems are rarely exemplified in studies of the role of pollinators in plant evolution and diversification. Although first recognised more than a century ago, specialised associations between cycads and their insect pollinators have been elucidated experimentally only in the past few decades. This review covers the history of understanding pollination in cycads, the advances that have been made since the 1980s using field observations and experiments, and analyses of molecular data from the population to phylum level. We outline areas for future research to address how such interactions might have affected speciation and extinctions. We stress that inclusion of cycads in broader considerations of the role of pollinators in plant diversification is important because they are phylogenetically distant from flowering plants and their pollination systems might have evolved independently of one another. This review is timely because cycads are a globally threatened group that might be vulnerable to co-extinction with pollinator loss.

In this study, we developed a new type of ferroelectret cellular film by using commercial polypropylene film (PQ60). We first use gas diffusion expansion method to create the void structure inside PQ60 followed by using corona discharge to trap charges in the voids. Then dynamic method was chosen to measure the piezoelectric constant d33. The measured d33 value was above 150 pC/N. We further use Laser-Intensity-Modulation Method to measure the heat induced current from the surface of the cellular PQ60 film at various intensity-modulated frequencies. The result of LIMM can be used to analyze sensor and actuator performance in ferroelectret.

Significant efforts have been devoted to developing trace-level quantification of Hg2+. In this work, a novel fluorescence detection (FD) approach combined with preconcentration of Hg2+ in ionic liquid (IL), N-octylpyridinium tetrafluoroborate ([OPy]+[BF4]−), was developed for the determination of trace Hg2+ in water. The temperature-controlled ionic liquid dispersive liquid–liquid microextraction (TC-IL-DLLME) technique was used to improve the enrichment factor. After extraction and centrifugal separation, precipitated IL was diluted with water and acetonitrile containing the fluorescent probe. Under optimum conditions, the photoluminescence intensity of the fluorescence emission peak was found to be linear with the concentration of Hg2+ in the range from 0.1 to 0.5 μg L−1. The limit of detection for the TC-IL-DLLME-FD method was calculated to be 0.0342 μg L−1 (S/N = 3). Further, the selectivity of the sensor was measured by evaluating its response to other heavy-metal ions and was shown to be excellent. Recoveries were assessed by spiking water samples with different Hg2+ standard stock solutions, giving satisfactory recoveries from 80 to 110%.

Background: Music therapy improves neuronal activity and connectivity of healthy persons and patients with clinical symptoms of neurological diseases like Parkinson’s Disease, Alzheimer’s Disease, and Major Depression. Despite the plethora of publications that have reported the positive effects of music interventions, little is known about how music improves neuronal activity and connectivity in afflicted patients. In this three-part series of studies, each of the three neurological disorders – (1) Parkinson’s Disease, (2) Alzheimer’s Disease, and (3) Major Depression – will be treated individually in detail. Methods: For patients suffering from Parkinson’s Disease (PD), we propose a daily 25-minute music-based synchronous finger tapping (SFT) intervention for 8-weeks. Participants will be each split into two groups: an intervention group and a control arm. Assessment of finger tapping performances, the Unified Parkinson’s Disease Rating Scale (UPDRS), an n-back test, the Montreal Cognitive Assessment (MoCA), as well as oxygenated- (HbO 2 ), deoxygenated- hemoglobin (HbR), and total hemoglobin activation collected by functional near-infrared spectroscopy (fNIRS) will be measured at baseline, week 4 (during), week 8 (post), and week 12 (retention) of the study. Data collected from the two PD groups will be compared to baseline performances from healthy controls.Discussion: The trial study investigates the cortical neuronal activity and therapeutic effects associated with an auditory external cue used to induce automatic and implicit synchronous finger tapping in patients diagnosed with PD. The extent to which the intervention is effective may be dependent on the severity of the disease.

Glass-ceramics (GCs) are preferred over glass or ceramics in certain optical applications including those requiring lower porosity than ceramics and higher transition temperatures than glass. However, due to its material heterogeneity, it is difficult to precisely control the microstructure in GCs to meet specific property targets. The chemical mechanism behind the microstructural changes in the two-phase heterogeneity has not yet been clearly elucidated. In this work, the continuous Reactive Force Field molecular dynamics nanoindentation algorithm was developed and used to study the mechanism of structural evolution during nanoindentation. It was found that crystalline phases (CP) had the maximum load at the same indentation depth. The number of point defects of CP was more than glass-crystalline phase (GCP) at the end of loading. However, after total unloading, the opposite was observed with the number of point defects in GCP more than that in CP. The details in GCP bonding indicated that the formation of irreversible supersaturated bonds hindered the healing of defects while promoting the annihilation of pores. The evolution of pores and the typical chemical changes of GCP in the nanoindentation process had also been explored, which proves to be helpful in understanding the behaviors of two-phase heterogeneous materials at the nanoscale.

Purpose Two-photon excitation fluorescence (2PEF) reveals information about tissue function. Concerns for phototoxicity demand lower light exposure during imaging. Reducing excitation light reduces the quality of the image by limiting fluorescence emission. We applied deep learning (DL) super-resolution techniques to images acquired from low light exposure to yield high-resolution images of retinal and skin tissues. Methods We analyzed two methods: a method based on U-Net and a patch-based regression method using paired images of skin (550) and retina (1200), each with low- and high-resolution paired images. The retina dataset was acquired at low and high laser powers from retinal organoids, and the skin dataset was obtained from averaging 7 to 15 frames or 70 frames. Mean squared error (MSE) and the structural similarity index measure (SSIM) were outcome measures for DL algorithm performance. Results For the skin dataset, the patches method achieved a lower MSE (3.768) compared with U-Net (4.032) and a high SSIM (0.824) compared with U-Net (0.783). For the retinal dataset, the patches method achieved an average MSE of 27,611 compared with 146,855 for the U-Net method and an average SSIM of 0.636 compared with 0.607 for the U-Net method. The patches method was slower (303 seconds) than the U-Net method (

An integrated centrifugal microfluidic device was developed to preconcentrate and detect hazardous mercury (II) in water with ionic liquid as environmentally friendly extractant. An automatically salt-controlled ionic liquid dispersive liquid&ndash, liquid microextraction on a centrifugal microfluidic device was designed, fabricated, and characterized. The entire liquid transport mixing and separation process was controlled by rotation speed, siphon valves, and capillary valves. Still frame images on the rotating device showed the process in detail, revealing the sequential steps of mixing, siphon priming, transportation between chambers, and phase separation. The preconcentration of red dye could be clearly observed with the naked eye. By combining fluorescence probe and microscopy techniques, the device was tested to determine ppb-level mercury (II) in water, and was found to exhibit good linearity and low detection limit.

With the fast growing of artificial intelligence (AI), more and more applications require querying uncertain data, especially from social media and crowd sourcing platform. In situations where it is impossible to increase data quality by controlling the sources, we may resort to algorithms to make the best use of the collected data. Since crowdsourcing provides a useful way to distributing tasks to mass people, and collects labels from as many workers as possible, many researchers have been study crowd-sourcing inference algorithms. In our work, we propose a novel crowd-sourcing inference algorithm to infer ground truth and obtain worker reliability and task difficulty at the same time.

A novel approach to the design and fabrication of field-emission tips with self-aligned gates intended for electric propulsion micro-thruster applications is presented. Their micro-electromechanical systems fabrication process is derived from the recent proliferation of research toward developing field emitter arrays, which are used primarily for field-emission flat-panel display applications. An array of micron-sized tips for electric field enhancement via wet isotropic etching of silicon, using silicon nitride as a hard mask is fabricated. The wet etching is accomplished using a combination of hydrofluoric, nitric, and acetic acids. The tips were then coated with a metal layer to enhance wetting by indium, the proposed propellant. Next, a layer of SU-8 photoresist was applied by spin coating and patterned to serve as a dielectric spacer. A second layer of metal was then applied to serve as a gate electrode. In addition, the results of electrostatic simulations of the prototype is described.

Objectives/Hypothesis Permanent facial nerve injury is a difficult challenge for both patients and physicians given its potential for debilitating functional, cosmetic, and psychological sequelae. Although current surgical interventions have provided considerable advancements in facial nerve rehabilitation, they often fail to fully address all impairments. We aim to introduce an alternative approach to facial nerve rehabilitation. Study Design Acute experiments in animals with normal facial function. Methods The study included three anesthetized cats. Four facial muscles (levator auris longus, orbicularis oculi, nasalis, and orbicularis oris) were monitored with a standard electromyographic (EMG) facial nerve monitoring system with needle electrodes. The main trunk of the facial nerve was exposed, and a 16-channel penetrating electrode array was placed into the nerve. Electrical current pulses were delivered to each stimulating electrode individually. Elicited EMG voltage outputs were recorded for each muscle. Results Stimulation through individual channels selectively activated restricted nerve populations, resulting in selective contraction of individual muscles. Increasing stimulation current levels resulted in increasing EMG voltage responses. Typically, selective activation of two or more distinct muscles was successfully achieved via a single placement of the multi-channel electrode array by selection of appropriate stimulation channels. Conclusion We have established in the animal model the ability of a penetrating electrode array to selectively stimulate restricted fiber populations within the facial nerve and to selectively elicit contractions in specific muscles and regions of the face. These results show promise for the development of a facial nerve implant system. Level of Evidence N/A.Laryngoscope, 2016 127:460–465, 2017

Ceratophila new genus (Erotylidae: Pharaxonothinae) inhabiting male cones of the Mesoamerican cycad genus Ceratozamia Brongniart (Zamiaceae) is described for seven new species and compared to other genera of the Pharaxonothinae. Ceratophila differs from other genera of the Pharaxonothinae in many characters, most notable of which are: lateral pronotal carina thicker anteriorly in lateral view; head with supraocular and transverse occipital lines; elytra lacking a basal bead; and stridulatory files at base of head narrowly separated. Ceratophila has the male genitalia laterally compressed with a short median lobe and flagellum, similar to other Erotylidae. In comparison, the most superficially similar pharaxonothine genus Pharaxonotha Reitter has: lateral pronotal carina thin along entire length; head lacking supraocular lines, but with transverse occipital lines; elytra with distinct basal bead; stridulatory files at base of head widely separated; and unique male genitalia that are dorsoventrally flattened with a long median lobe and flagellum. Ceratophila contains two subgenera, which differ most notably in external characters and sexual dimorphism. Members of Ceratophila ( Ceratophila ), the nominal subgenus, have: more cylindrical bodies, pronotum evenly convex dorsally; the pronotum lacking basal longitudinal grooves on disc; metatibiae that are distinctly triangularly dilated toward apex; and no apparent external sexual dimorphism. In comparison, members of Ceratophila ( Vovidesa ) new subgenus have: dorsoventrally flattened bodies; the pronotum explanate (concave) along lateral margins; the pronotum with basal longitudinal grooves on disc; metatibiae weakly or not dilated toward apex; and with all tibiae in males showing strong sexual dimorphism. Four new species are described within the subgenus Ceratophila : C . ( C .) chemnicki , C . ( C .) gregoryi , C . ( C .) picipennis , C . ( C .) sanchezae; and three new species are described within the subgenus Vovidesa : C . ( V .) chiapensis , C . ( V .) mixeorum , C . ( V .) vazquezi . Keys to genera, subgenera and species of known adults based on morphology are provided.

The top challenges for widespread application of ventricular assist device are infections of the driveline and pump thrombosis of the device. This project makes use of the powerful multiphysics computational simulation to improve the design of the left ventricular assist devices, by eliminating the driveline and streamlining the pump interior blood contacting surfaces. The design optimization involves balancing the wireless power transfer efficiency, implant miniaturization, and the regulatory compliance.

In this paper, we report a new type of electrospinning collector that allows simultaneous collection and alignment of multiple poly(vinylidene fluoride-trifluoroethylene) piezoelectric fiber bundles with a controlled separation. The key enabling feature is the serrated teeth along the edges across an inclined gap as a part of the conductive collector. As a result, the electrical field across the gap is shaped to direct the electrospun fibers to merge into multiple bundles. The sharp points on the serrated teeth provide favorable charge dissipation points and thus fibers are preferentially formed bridging two closest sharp points across the gap. To investigate the effectiveness of serrated teeth on the formation of multiple fiber bundles, three-dimensional finite element simulations are conducted. The corresponding collectors are implemented to experimentally study the resulting electrospun fibers. Both simulation and experimental results suggest that multiple fiber bundles can be formed under the condition of a low teeth pitch to gap distance ratio. Furthermore, a sharper tooth angle results in a higher preferential formation of fiber bundles. Finally, the total electrospinning time should be less than 60 seconds to maintain favorable electric field profile. We also demonstrate that these piezoelectric fiber bundles can serve as ultra-flexible textile sensors.

In this paper, we describe a novel and simple process for the fabrication of all-transparent and encapsulated polymeric nanofluidic devices using nano-indentation lithography. First, a nanomechanical probe is used to ‘scratch’ nanoscale channels on polymethylmethacrylate (PMMA) substrates with sufficiently high hardness. Next, polydimethylsiloxane (PDMS) is used twice to duplicate the nanochannels onto PDMS substrates from the ‘nano-scratched’ PMMA substrates. A number of experiments are conducted to explore the relationships between the nano-indentation parameters and the nanochannel dimensions and to control the aspect ratio of the fabricated nanochannels. In addition, traditional photolithography combined with soft lithography is employed to fabricate microchannels on another PDMS ‘cap’ substrate. After manually aligning the substrates, all uncovered channels on two separate PDMS substrates are bonded to achieve a sealed and transparent nanofluidic device, which makes the dimensional transition from microscale to nanoscale feasible. The smallest dimensions of the achievable nanochannels that we have demonstrated thus far are of ~20 nm depth and ~800 nm width, with lengths extendable beyond 100 μm. Fluid flow experiments are performed to verify the reliability of the device. Two types of colloidal solution are used to visualize the fluid flow through the nanochannels, that is, ethanol is mixed with gold colloid or fluorescent dye (fluorescein isothiocyanate), and the flow rate and filling time of liquid in the nanochannels are estimated based on time-lapsed image data. The simplicity of the fabrication process, bio-compatibility of the polymer substrates, and optical transparency of the nanochannels for flow visualization are key characteristics of this approach that will be very useful for nanofluidic and biomolecular research applications in the future.

This article reports a perfusion-based microbioreactor that can be integrated with a thin-film piezoelectric transducer array for rapid disease diagnosis, such as identifications of cancer cells and infection induced cell abnormality. By using the gap between suspended transducers as the high-aspect ratio barriers to establish high flow resistance into the culture chamber, we have verified that diffusion dominated the main transport mechanisms in the culture chamber. The fluid flow was successfully suppressed under 0.03, 0.3, and 3.0 μl/min volume flow rates, and a very low shear flow region was achieved on the transducer surfaces. This design offers minimal influences of mechanical forces on cellular detection and cells cultured on the surface of transducers. Finite element simulation showed that the shear stress on transducer surface could be maintained lower than milli-Pascal range. Detailed design, simulation results and experimental verifications of the microbioreactor are discussed.

The attachment of cells to the extracellular matrix (ECM) is achieved by the specific binding of cell-surface receptors to ligands present in the ECM. These interactions are important for many biological processes, including cell migration, cancer development, and wound healing. Our objective was to develop a computational model to investigate how focal adhesion mechanical properties, substrate stiffness, and intracellular stresses affect cell–matrix interactions during cell migration on a flat substrate. In our model, the cell–substrate traction was proportional to the bound receptor concentration, relative velocity between the cell and substrate, and the cell–substrate friction coefficient. Simulation results showed that even if the receptor number and ligand density were fixed, the mechanical properties of the focal adhesions still affected cell–ECM interactions. In fact, the cell–substrate traction was biphasic with respect to the friction coefficient, a parameter that can be used to quantify focal adhesion properties. In contrast, the cell speed was a monotonically decreasing function with respect to this parameter. Furthermore, tractions showed greater increases when the maximum intracellular stress was increased from 400 to 600 Pa than when substrate stiffness was increased from 0.5 to 100 kPa. This mathematical model is able to quantify the effects of focal adhesion mechanical properties, extracellular stiffness, and intracellular stresses on cell–ECM interactions, and should be beneficial to research in cancer development.

Two major lineages of beetles inhabit cycad cones in the New World: weevils (Curculionoidea) in the subtribe Allocorynina, including the genera Notorhopalotria Tang and O’Brien, Parallocorynus Voss, Protocorynus O’Brien and Tang and Rhopalotria Chevrolat, and beetles in the family Erotylidae, including the genus Pharaxonotha Reitter. Analysis of the 16S ribosomal RNA (rRNA) mitochondrial gene as well as cladistic analysis of morphological characters of the weevils indicate four major radiations, with a probable origin on the cycad genus Dioon Lindl. and comparatively recent host shifts onto Zamia L. Analysis of the 16S rRNA gene for erotylid beetles indicates that an undescribed genus restricted to New World Ceratozamia Brongn. is the most early-diverging clade, and this lineage is sister to a large radiation of the genus Pharaxonotha onto Zamia, with apparent host shifts onto Dioon and Ceratozamia. Analysis of beetles are in accord with current models of continental drift in the Caribbean basin, support some proposed species groupings of cycads, but not others, and suggest that pollinator type may impact population genetic structure in their host cycads.

This paper presents a sensitive compliance measurement system for determining the stiffness of the adult rat hippocampus. The device has been successfully fabricated which consists of two strain gauges incorporated in the SU-8 based cantilever. The cantilever-sensor has been fully characterized and its strain sensitivity was found to be approximately 2.5. in vitro testing on the brain tissue has successfully demonstrated that the system is sufficiently sensitive to provide distinctive direct stiffness measurements on various hippocampal regions.