PC Chip Research Articles

In vitro spermatogenesis in two-dimensionally spread mouse testis tissues.

PurposeMouse in vitro spermatogenesis is possible with classical organ culture methods, by placing the testis tissue at the interphase between culture medium and air. In this condition, however, a tissue piece tends to round up to be compact, whose central region suffers from shortage of nutrients and oxygen. In this study, the authors improved the culture condition by spreading each tissue thin and flat, by which they were able to get better access to the oxygen and nutrients.MethodsImmature mouse testis tissues placed on agarose gel block were forced to spread flat by covering with a polydimethylsiloxane (PDMS) ceiling chip (PC chip). They were then cultured for weeks and evaluated by the transgene expression of Acr‐Gfp, which reflects the progression of spermatogenesis.ResultsTestis tissues covered with PC chip initiated and maintained spermatogenesis in its wider region than those without PC chip covering. Flow cytometric analysis demonstrated that the PC method yielded more numerous meiotic germ cells than those without PC. Immunohistochemical examination confirmed the authentic histological figure of spermatogenesis from spermatogonia up to round or elongating spermatids.ConclusionsThe PC chip method is simple and effective to improve the efficiency of in vitro spermatogenesis in the organ culture system.

Photonic crystal surface mode imaging biosensor based on wavelength interrogation of resonance peak

A novel biosensing technique with a two-dimensional (2D) visualization, which is based on photonic crystal surface modes (PC SMs), is presented. The 2D image of the surface with picometer thickness resolution can be obtained when the PC chip under study is placed between crossed polarizers to convert a PC SM resonance dip into a resonance peak. The PC chip is designed so that the PC SM resonance peak is located between the maxima of the blue and green pixels of a color camera. The spectral shift of the resonance peak is determined by balancing of the intensities of the blue and green pixels at each point in the color camera. The spatial distribution of resonance wavelength shifts across the camera reflects the spatial distribution of changes in the thickness of the adsorbate over the sample. The spatial resolution of the resulting 2D image is determined by the propagation length of the PC surface wave.

Kinetics of Antibody Binding to Membranes of Living Bacteria Measured by a Photonic Crystal-Based Biosensor.

Optical biosensors based on photonic crystal surface waves (PC SWs) offer a possibility to study binding interactions with living cells, overcoming the limitation of rather small evanescent field penetration depth into a sample medium that is characteristic for typical optical biosensors. Besides this, simultaneous excitation of s- and p-polarized surface waves with different penetration depths is realized here, permitting unambiguous separation of surface and volume contributions to the measured signal. PC-based biosensors do not require a bulk signal correction, compared to widely used surface plasmon resonance-based devices. We developed a chitosan-based protocol of PC chip functionalization for bacterial attachment and performed experiments on antibody binding to living bacteria measured in real time by the PCSW-based biosensor. Data analysis reveals specific binding and gives the value of the dissociation constant for monoclonal antibodies (IgG2b) against bacterial lipopolysaccharides equal to KD = 6.2 ± 3.4 nM. To our knowledge, this is a first demonstration of antibody-binding kinetics to living bacteria by a label-free optical biosensor.

Genome-Wide Ultrabithorax Binding Analysis Reveals Highly Targeted Genomic Loci at Developmental Regulators and a Potential Connection to Polycomb-Mediated Regulation.

Hox homeodomain transcription factors are key regulators of animal development. They specify the identity of segments along the anterior-posterior body axis in metazoans by controlling the expression of diverse downstream targets, including transcription factors and signaling pathway components. The Drosophila melanogaster Hox factor Ultrabithorax (Ubx) directs the development of thoracic and abdominal segments and appendages, and loss of Ubx function can lead for example to the transformation of third thoracic segment appendages (e.g. halters) into second thoracic segment appendages (e.g. wings), resulting in a characteristic four-wing phenotype. Here we present a Drosophila melanogaster strain with a V5-epitope tagged Ubx allele, which we employed to obtain a high quality genome-wide map of Ubx binding sites using ChIP-seq. We confirm the sensitivity of the V5 ChIP-seq by recovering 7/8 of well-studied Ubx-dependent cis-regulatory regions. Moreover, we show that Ubx binding is predictive of enhancer activity as suggested by comparison with a genome-scale resource of in vivo tested enhancer candidates. We observed densely clustered Ubx binding sites at 12 extended genomic loci that included ANTP-C, BX-C, Polycomb complex genes, and other regulators and the clustered binding sites were frequently active enhancers. Furthermore, Ubx binding was detected at known Polycomb response elements (PREs) and was associated with significant enrichments of Pc and Pho ChIP signals in contrast to binding sites of other developmental TFs. Together, our results show that Ubx targets developmental regulators via strongly clustered binding sites and allow us to hypothesize that regulation by Ubx might involve Polycomb group proteins to maintain specific regulatory states in cooperative or mutually exclusive fashion, an attractive model that combines two groups of proteins with prominent gene regulatory roles during animal development.

Design of Temperature Monitoring System of Labouratory Based on VB

Serial communication of pc and single chip microcomputer was presented based on MSCOMM control of Visual Basic 6.0. Some properties of MSCOMM control were expounded. This system has the functions of data collecting, data displaying, data recording, historical data query, curve drawing and so on.

Computational Fluid Dynamics Assisted Control System Design With Applications to Central Processing Unit Chip Cooling

In this paper, a computational fluid dynamics (CFD) assisted control system design methodology has been described in detail. The entire design and evaluation procedure has been illustrated through a feedback control system synthesis for a central processing unit (CPU) chip cooling system. The design methodology starts with a full-scale CFD simulation of the nonlinear dynamic process to generate the input and output databases of the process. Using this data set, linear dynamic models around specified operating points are obtained using system identification techniques. Based on these models, one can design appropriate control systems to meet the required closed-loop control system specifications. To illustrate the effectiveness of this technique, it has been used to design a controller for a PC chip cooling system. In particular, the coupling issues between ‘real-time’ dynamic controllers with non real-time CFD simulation have been resolved. A physical experimental test bench based on a cooling system of a Pentium III CPU has been constructed. The feedback linear control systems designed by the proposed CFD approach have been evaluated experimentally for six CPU load conditions.

Design of the Centralized Control Circuit for Large Ship Borne Squid Jigging Machine

Squid jigging machine is an important equipment in the oceanic squid jigging fisheries. Now, we have used the intelligent squid fishing machine, though, we have to guard the machine one by one. To reduce the labor on deck, we designed a serial interface circuit between PC and Single Chip Microcomputer (SCM) for the communication within multiple squid jigging machines by the way of RS-485 bus, realizing centralized control of machines. For hardware, we converted TTL level to 485 level by serial interface conversion chip so that SCM could achieve RS-485 interface communication; For software, we customized instruction sets, data package format, communication protocol format. We designed RS-485 bus interface circuit for PC and SCM by simulation software Proteus. Through tests in the field, we knew the circuit makes the connection of centralized control network simple, and signal transmission reliable. We will pay particular attention to the design of communication protocols software, which can provide new thinking of designing about communication within multiple machines for the researchers.

Design and Simulation of the Communication Circuit on Multi Jigging Machines

Squid jigging machine is an important equipment in the oceanic squid jigging fisheries. In order to take centralized control of multi jigging machines, improve manufacturing efficiency, this paper introduce the centralized control circuit between PC and single chip microcomputer for the communication within multi jigging machines by the way of RS-485 bus in detail, and we focus on describing the design of the hardware circuit for the centralized control system. The master is PC while the slave is MCS-51. The communication between them is realized by the MSComm control in VB6.0. It researches practicable ways to improve the reliability of RS-485 bus system, respectively from different aspects such as bus conflict, burst interference, common mode interference and nodes fault and so on. This study provides reference data for the researchers.

FPGA Implementation for Real-Time Empirical Mode Decomposition

This paper presents a novel field-programmable gate array (FPGA) based method for empirical mode decomposition (EMD) in real time. Traditionally, EMD can be easily implemented and developed using a high-level computer language in a PC or DSP chip. However, it is difficult to implement EMD in a hardware environment. This paper develops EMD for real-time applications using a hardware-based FPGA. The proposed FPGA-based method calculates the upper and lower envelopes in EMD point by point by using a circular queue to temporarily store values of maxima and minima, from which the upper and lower envelopes in the EMD can be determined continuously. Additionally, an attempt is made to increase the efficiency of the computational process by cascading several identical modules as a serial pipeline structure in order to conduct an iterative loop for calculating the intrinsic mode functions in EMD. The fast process from the serial pipeline structure results in real-time computation with a sampling rate of up to 12.5 MHz and mitigation of the end effect. The proposed method is validated by the simulation results obtained by Quartus II and verified by FPGA (Altera Stratix III EP3SL150F1152C2) realization, revealing its effectiveness in real-time applications.

Wintel Under the Antitrust Microscope: A Comparison of the European Intel Case with the U.S. Microsoft Cases, Updated as of May 12, 2009

European Union has issued a statement of objections, and a supplemental statement of objections, to Intel regarding the company’s conduct aimed at suppressing competition from Intel’s chief rival, AMD. Although the statements of objections remain confidential, the allegations in AMD’s private litigation are public and provide a useful basis for analysis. Intel dominates the PC chip market almost to the same degree that Microsoft dominates the PC operating system market. As in the Microsoft case, Intel’s aggressive marketing tactics prevented OEMs from offering rival products to consumers. And like Microsoft, Intel has engaged in this conduct to maintain its existing monopoly. These parallels between the Microsoft and Intel suggest that Intel’s anticompetitive practices harm consumers, including American consumers, by denying them the access to innovative products at lower prices from rivals. The United States established that Microsoft repeatedly and willfully violated the antitrust laws, but failed to achieve an effective remedy. The EU, however, should have an easier time achieving an effective remedy. First, unlike the OS market, a viable competitor still exists in the chip market, i.e., AMD. Second, Intel has relied primarily on exclusionary rebates, not commingling of intellectual property, to maintain its monopoly. Consequently, the EU should be able to fashion a remedy that does not require Intel to redesign its product.

Wintel Under the Antitrust Microscope: A Comparison of the European Intel Case with the U.S. Microsoft Cases

The European Union has issued a statement of objections to Intel regarding the company's conduct aimed at suppressing competition from Intel's chief rival, AMD. Although the statement of objections remains confidential, the allegations in AMD's private litigation are public and provide a useful basis for analysis. Intel dominates the PC chip market almost to the same degree that Microsoft dominates the PC operating system market. As in the Microsoft case, Intel's aggressive marketing tactics prevented OEMs from offering rival products to consumers. And like Microsoft, Intel has engaged in this conduct to maintain its existing monopoly. These parallels between the Microsoft and Intel suggest that Intel's anticompetitive practices harm consumers, including American consumers, by denying them the access to innovative products at lower prices from rivals. The United States established that Microsoft repeatedly and willfully violated the antitrust laws, but failed to achieve an effective remedy. The EU, however, should have an easier time achieving an effective remedy. First, unlike the OS market, a viable competitor still exists in the chip market, i.e., AMD. Second, Intel has relied primarily on exclusionary rebates, not commingling of intellectual property, to maintain its monopoly. Consequently, the EU should be able to fashion a remedy that does not require Intel to redesign its product.

An Improved Distortion Solution for the Hubble Space Telescope’s WFPC211Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5‐26555.

ABSTRACTHaving an accurate distortion correction is critical to doing accurate astrometry with the Wide Field Planetary Camera 2. Currently available solutions have serious systematic errors (∼0.2 pixel) of a skewing nature in their linear terms. We use the inner calibration field of ω Centauri to find an improved cubic solution that is accurate to ±0.01 pixel in the WF chips and to ±0.02 pixel in the PC chip. Improvements beyond this will be difficult, as there are many factors that perturb the solution at the ∼0.01 pixel level: breathing, variations with filter, and the physical movement of the chips. There are probably not enough data available to constrain the solution to better than ∼0.01 pixel. Nevertheless, our solution is a major improvement and will allow many astrometric projects to obtain near‐optimal results.

PC chip sets reduce chip count : Chris Terry. EDN. 57 (1 October 1990)

PC chip sets reduce chip count : Chris Terry. EDN. 57 (1 October 1990)