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Macrophages can associate with extracellular matrix (ECM) demonstrating nanosequenced cell-adhesive RGD ligand. In this study, we devised barcoded materials composed of RGD-coated gold and RGD-absent iron nanopatches to show various frequencies and position of RGD-coated nanopatches with similar areas of iron and RGD-gold nanopatches that maintain macroscale and nanoscale RGD density invariant. Iron patches were used for substrate coupling. Both large (low frequency) and externally positioned RGD-coated nanopatches stimulated robust attachment in macrophages, compared with small (high frequency) and internally positioned RGD-coated nanopatches, respectively, which mediate their regenerative/anti-inflammatory M2 polarization. The nanobarcodes exhibited stability in vivo. We shed light into designing ligand-engineered nanostructures in an external position to facilitate host cell attachment, thereby eliciting regenerative host responses.

Developing materials with remote controllability of macroscale ligand presentation can mimic extracellular matrix (ECM) remodeling to regulate cellular adhesion in vivo. Herein, we designed charged mobile nanoligands with superparamagnetic nanomaterials amine-functionalized and conjugated with polyethylene glycol linker and negatively charged RGD ligand. We coupled negatively a charged nanoligand to a positively charged substrate by optimizing electrostatic interactions to allow reversible planar movement. We demonstrate the imaging of both macroscale and in situ nanoscale nanoligand movement by magnetically attracting charged nanoligand to manipulate macroscale ligand density. We show that in situ magnetic control of attracting charged nanoligand facilitates stem cell adhesion, both in vitro and in vivo, with reversible control. Furthermore, we unravel that in situ magnetic attraction of charged nanoligand stimulates mechanosensing-mediated differentiation of stem cells. This remote controllability of ECM-mimicking reversible ligand variations is promising for regulating diverse reparative cellular processes in vivo.

Search is one of the most popular and important web services. The inverted index is the standard data structure adopted by most full-text search engines. Recently, custom hardware accelerators for inverted index search have emerged to demonstrate much higher throughput than the conventional CPU or GPU. However, less attention has been paid to addressing the memory capacity pressure with inverted index. The conventional DDRx DRAM memory system significantly increases the system cost to make a terabyte-scale main memory. Instead, a shared memory pool composed of storage-class memory (SCM) devices is a promising alternative for scaling memory capacity at a much lower cost. However, this SCM-based pooled memory poses new challenges caused by the limited bandwidth of both SCM devices and the shared interconnect to the host CPU. Thus, we propose BOSS, the first near-data processing (NDP) architecture for inverted index search on SCM-based pooled memory, which maintains high throughput of query processing in this bandwidth- constrained environment. BOSS mitigates the impact of low bandwidth of SCM devices by employing early-termination search algorithms, reducing the footprint of intermediate data, and introducing a programmable decompression module that can select the best compression scheme for a given inverted index. Furthermore, BOSS includes a top-k selection module in hardware to substantially reduce the host-accelerator bandwidth consumption. Compared to Apache Lucene, a production-grade search engine library, running on 8 CPU cores, BOSS achieves a geomean speedup of 8.1× on various complex query types, while reducing the average energy consumption by 189×.

Native extracellular matrix (ECM) can exhibit cyclic nanoscale stretching and shrinking of ligands to regulate complex cell-material interactions. Designing materials that allow cyclic control of changes in intrinsic ligand-presenting nanostructures in situ can emulate ECM dynamicity to regulate cellular adhesion. Unprecedented remote control of rapid, cyclic, and mechanical stretching ("ON") and shrinking ("OFF") of cell-adhesive RGD ligand-presenting magnetic nanocoils on a material surface in five repeated cycles are reported, thereby independently increasing and decreasing ligand pitch in nanocoils, respectively, without modulating ligand-presenting surface area per nanocoil. It is demonstrated that cyclic switching "ON" (ligand nanostretching) facilitates time-regulated integrin ligation, focal adhesion, spreading, YAP/TAZ mechanosensing, and differentiation of viable stem cells, both in vitro and in vivo. Fluorescence resonance energy transfer (FRET) imaging reveals magnetic switching "ON" (stretching) and "OFF" (shrinking) of the nanocoils inside animals. Versatile tuning of physical dimensions and elements of nanocoils by regulating electrodeposition conditions is also demonstrated. The study sheds novel insight into designing materials with connected ligand nanostructures that exhibit nanocoil-specific nano-spaced declustering, which is ineffective in nanowires, to facilitate cell adhesion. This unprecedented, independent, remote, and cytocompatible control of ligand nanopitch is promising for regulating the mechanosensing-mediated differentiation of stem cells in vivo.

The native extracellular matrix (ECM) can exhibit heterogeneous nano-sequences periodically displaying ligands to regulate complex cell-material interactions in vivo. Herein, an ECM-emulating heterogeneous barcoding system, including ligand-bearing Au and ligand-free Fe nano-segments, is developed to independently present tunable frequency and sequences in nano-segments of cell-adhesive RGD ligand. Specifically, similar exposed surface areas of total Fe and Au nano-segments are designed. Fe segments are used for substrate coupling of nanobarcodes and as ligand-free nano-segments and Au segments for ligand coating while maintaining both nanoscale (local) and macroscale (total) ligand density constant in all groups. Low nano-ligand frequency in the same sequences and terminally sequenced nano-ligands at the same frequency independently facilitate focal adhesion and mechanosensing of stem cells, which are collectively effective both in vitro and in vivo, thereby inducing stem cell differentiation. The Fe/RGD-Au nanobarcode implants exhibit high stability and no local and systemic toxicity in various tissues and organs in vivo. This work sheds novel insight into designing biomaterials with heterogeneous nano-ligand sequences at terminal sides and/or low frequency to facilitate cellular adhesion. Tuning the electrodeposition conditions can allow synthesis of unlimited combinations of ligand nano-sequences and frequencies, magnetic elements, and bioactive ligands to remotely regulate numerous host cells in vivo.

In native microenvironment, diverse physical barriers exist to dynamically modulate stem cell recruitment and differentiation for tissue repair. In this study, we utilize nanoassembly-based magnetic screens of various sizes and elastically tethered them over RGD ligand (cell-adhesive motif)-presenting material surface to generate various nano-gaps between the screens and the RGDs without modulating the RGD density. Large screens exhibiting low RGD distribution stimulate integrin clustering to facilitate focal adhesion, mechanotransduction, and differentiation of stem cells, which were not observed with small screens. Magnetic downward pulling of the large screens decreases nano-gaps, which dynamically suppress the focal adhesion, mechanotransduction, and differentiation of stem cells. Conversely, magnetic upward pulling of the small screens increases the nano-gaps, which dynamically activate focal adhesion, mechanotransduction, and differentiation of stem cells. This regulation mechanism was also shown to be effective in the microenvironment in vivo. Further diversifying geometries of the physical screens could further enable diverse modalities of multifaceted and safe unscreening of the distributed RGDs to unravel and modulate stem cell differentiation for tissue repair. This article is protected by copyright. All rights reserved.

In this paper, a relative heat exchange rate is numerically compared for cast-in-place concrete energy piles with d ifferent heat exchange pipe configurations, and a new design method for energy piles is proposed. An equivalent heat exchange rate was estimated for the W-type (one series loop), multiple U- type (four parallel loops), and coil-type heat exchanger installed in the same large-diam eter drilled shaft. In order to simulate a cooling operation in summer by a CFD analysis, the LWT (leaving water temperature) into a energy pile was fixed at 35 °C and then the EWT (entering water temperature) into a heat pump was monitored. In case of continuously applyi ng the artificial maximum cooling load for 100 hours, all of the three types of heat exchangers show the marginally similar heat e xchange rate. However, in case of intermittently applying the cooling load with a cycle of 8 hours operation-16 hours off for 7 consecu tive days, the coil type heat exchanger exhibits a heat exchange rate only 86 % of the multiple U-type due to measurable thermal interference between pipe loops in the energy pile. On the other hand, the W-type possesses the similar heat exchange rate to the multiple U -type. The equivalent heat exchange rates for each configuration of heat exchangers obtained from the CFD analysis were adopted for implementing the commercial design program (PILESIM2). Finally, a design method for cast-in-place concrete energy piles is proposed along with a design chart in consideration of typical design factors.Key words : Cast-in-place pile, Energy pile, Equivalent heat exchange rate, Computational fluid dynamic analysis, design method초 록본 연구에서는 현장타설 에너지파일의 열교환 파이프 배치 형태별 열교환율을 전산유체해석 프로그램 (FLUENT)을 이용하여 평가하고, 이를 이용하여 에너지파일의 설계법을 제시하였다. 등가열교환율을 산정하기 위해 동일한 현장타설말뚝 제원에 대해 열교환파이프 배치 형태를 W-형(직렬), 복합 U-형(병렬 4쌍), 나선형의 3가지로 고려하였다. 건물측 부하조건은 여름철 냉방운용를 모사하기 위해 순환수의 에너지파일 유입온도, 즉 히트펌프 유출온도(Leaving water temperature, LWT)를 35°C로 일정하게 유지하여 에너지파일 유출온도, 즉 히트펌프 유입온도(Entering water temperature, EWT) 변화를 관찰하였다. 지반에 최대 가상부하를 적용한 경우(100시간 연속 냉방부하 조건)에는 3가지 열교환기 형태가 유사한 열교환율을 보인 반면, 실제 히트펌프 가동에 의한 건물 냉방운용을 모사하기 위해 간헐적으로 일일 8시간 운용-16시간 정지를 7일간 반복 해석한 경우에는 W-형(직렬연결)과 복합 U-형(병렬 4쌍) 열교환기는 유사한 열교환율을 보이나, 나선형 열교환기는 파이프 루프 상호 간 열간섭으로 인해 복합 U-형 열교환기에 비해 약 86%의 열교환율을 갖는 것으로 평가되었다. 전산유체해석에 의해 계산된 열교환파이프 배치 형태별 에너지파일의 등가열교환율을 에너지파일 설계프로그램(PILESIM2)에 적용하여 다양한 형상의 현장타설 에너지파일에 대한 설계법과 대표적인 설계변수에 대한 설계도표를 제시하였다.검색어 : 현장타설말뚝, 에너지파일, 등가열교환율, 전산유체해석, 설계법

Performing a series of in-situ thermal response tests, the effective thermal conductivity of six vertical closed-loop ground heat exchangers was experimentally evaluated and compared to each other, which were constructed in a test bed in Wonju, South Korea. To compare thermal efficiency of the ground heat exchangers in field, the six boreholes were constructed with different construction conditions: i.e., different grouting materials (cement vs. bentonite), different shape of heat exchange pipe-sections (conventional U-loop type vs. new 3 pipe-type), and different additives (silica sand vs. graphite). One observation borehole was installed in the middle of the test site to measure a subsurface temperature change during performing the in-situ thermal response test. From the test results, it can be shown that cement grouting has a higher effective thermal conductivity than that of bentonite grouting, and graphite better performs over silica sand as a thermally enhancing addictive. In addition, a new 3 pipe-type heat exchanger yields less thermal interference between the inlet and outlet pipe than the conventional U-loop type heat exchanger, which results in superior thermal performance.

The applicability of cement grout (or cement-based grout) has been considered as an alternative to bentonite grout commonly used to backfill closed-loop vertical ground heat exchangers. In a geothermal heat pump system, repeated heating-cooling cycles may cause adverse effects on the integrity of cement grout in the ground heat exchanger. To account for the temperature cycling effect, the strength degradation of cement grout due to temperature cycling has been examined by measuring the unconfined compression strength of cured specimens in a humidity-temperature controlling chamber with applying temperature cycles between −5°C and 50°C. There is a tendency that the unconfined compression strength decreases with an increase in the number of temperature cycles. On the other hand, an equivalent hydraulic conductivity of a pipe-embedded cement grout specimen was evaluated by carrying out a modified flexible wall permeameter test equipped with a water circulating system to control temperature inside the pipe section. The applied operating temperature range was from 5 to 35°C. After three cycles of heating-cooling circulation, the equivalent hydraulic conductivity becomes asymptotic to a constant value, which implies there is no severe detachment of the pipe from the cement grout.

Sulfonated poly(ether ether ketone)/polyethyleneimine (sPEEK/PEI) composite membranes were prepared to reduce the water uptake and methanol permeability of highly sulfonated PEEK membranes (> 65%). Incorporation of small amounts of PEI reduced ionic cluster size via electrostatic complex formation between anionic sulfonic groups of the sPEEK and the cationic amine groups of the PEI, and thus affected membrane properties considerably. Ion cluster size decreased with increasing PEI concentration by small angle X-ray scattering pattern. Addition of 1 wt.% of PEI resulted in reduction of water uptake and methanol permeability by 30% at 60 °C and 85% at room temperature, respectively. The thermal and mechanical stabilities were also enhanced by formation of physical cross-linking induced by electrostatic interactions between acid/base polymers. Although proton conductivity was also reduced by PEI incorporation as a part of the sulfonic acid groups involved in ionic complex formation, its effect on proton conductivity was not as strong as on methanol permeability.

Background: Ameloblastoma is a benign, but locally invasive tumor known for its high rate of recurrence. However, few comprehensive genetic studies have been conducted about its tumorigenesis. Our aim was to identify possible genes involved in the development and progression of ameloblastoma, using microarray analysis with dentigerous cyst as a control. Methods: Total RNA was extracted from two fresh dentigerous cysts and ameloblastoma specimens. Following microarray analysis, semiquantitative reverse transcription–polymerase chain reaction (RT–PCR) and immunohistochemistry were performed on selected genes. Results: Seventy-three genes were overexpressed and 49 were underexpressed. These genes were divided into categories according to function. The microarray results for 13 selected genes were verified with semiquantitative RT–PCR. Conclusions: We identified important genes related to the development and progression of ameloblastoma through a large-scale gene expression analysis. This study will stimulate further investigations on genes significant for early diagnosis and prognosis of ameloblastoma.