An ultra-compact mechanical antenna based on PTFE highly charged electret for extremely low frequency communications.

-Extremely-Low Frequencies (ELF, 30∼300Hz) transmitting antennas in wireless communications are often limited by antenna size and complex impedance matching networks. In this paper, we propose an ultra-small Artificial Electret Type Mechanical Antenna (AETMA), which is composed of a single charge electret and a driving structure, with high radiation efficiency and small size. In order to improve the electric dipole moment of the mechanical antenna, we employ a pin-plate corona polarization technique and a unidirectional stretching treatment to obtain a porous thin-film electret that can stably store a large amount of charge. Its surface charge density can reach 5.355 mC/m2 and we analyze its surface potential stability. To assess the radiation capability of AETMA, the radiation field models of three kinds of mechanical antennas are established and verified by simulation. Additionally, we simulate and compare the planar electret and curved electret configurations to determine the optimal form of AETMA. The radiation intensity of the planar electret is found to be superior under the same moment of inertia. Finally, a 1m-scale artificial electret antenna is designed based on the optimal model. Comparative analysis with existing rotary mechanical antenna schemes confirms the great potential of the proposed AETMA for portable, miniaturized and high-performance wireless communication devices.

Photocrosslinked natural hydrogel composed of hyaluronic acid and gelatin enhances cartilage regeneration of decellularized trachea matrix.

Repair of long segmental trachea defects is always a great challenge in the clinic. The key to solving this problem is to develop an ideal trachea substitute with biological function. Using of a decellularized trachea matrix based on laser micropore technique (LDTM) demonstrated the possibility of preparing ideal trachea substitutes with tubular shape and satisfactory cartilage regeneration for tissue-engineered trachea regeneration. However, as a result of the very low cell adhesion of LDTM, an overly high concentration of seeding cell is required, which greatly restricts its clinical translation. To address this issue, the current study proposed a novel strategy using a photocrosslinked natural hydrogel (PNH) carrier to enhance cell retention efficiency and improve tracheal cartilage regeneration. Our results demonstrated that PNH underwent a rapid liquid-solid phase conversion under ultraviolet light. Moreover, the photo-generated aldehyde groups in PNH could rapidly react with inherent amino groups on LDTM surfaces to form imine bonds, which efficiently immobilized the cell-PNH composite to the surfaces of LDTM and/or maintained the composite in the LDTM micropores. Therefore, PNH significantly enhanced cell-seeding efficiency and achieved both stable cell retention and homogenous cell distribution throughout the LDTM. Moreover, PNH exhibited excellent biocompatibility and low cytotoxicity, and provided a natural three-dimensional biomimetic microenvironment to efficiently promote chondrocyte survival and proliferation, extracellular matrix production, and cartilage regeneration. Most importantly, at a relatively low cell-seeding concentration, homogeneous tubular cartilage was successfully regenerated with an accurate tracheal shape, sufficient mechanical strength, good elasticity, typical lacuna structure, and cartilage-specific extracellular matrix deposition. Our findings establish a versatile and efficient cell-seeding strategy for regeneration of various tissue and provide a satisfactory trachea substitute for repair and functional reconstruction of long segmental tracheal defects.

Electrospun nanofibrous membrane of fish collagen/polycaprolactone for cartilage regeneration.

Tissue engineering technology provides a promising approach for cartilage repair, and in this strategy, scaffolds play a pivotal role in directing cartilage regeneration. Fish collagen (FC) is currently considered an alternative source of mammalian collagen (MC) for tissue engineering due to its excellent biocompatibility, suitable biodegradability, inert immunogenicity, rich sources, low price and lack of risk for the transmission of zoonosis. Here, we fabricated three types of electrospun nanofibrous membranes composed of FC and polycaprolactone (PCL) with three different FC/PCL ratios (9/1, 7/3, 5/5) and investigated the feasibility of using the membranes with chondrocytes in cartilage regeneration. Our results demonstrated that increases in the FC content were associated with improvements in biodegradability, absorption, and cell adhesion capacity, but weaker mechanical properties. In addition, all three nanofibrous membranes showed satisfactory biocompatibility as evidenced by supporting chondrocyte proliferation and cartilage formation in vitro. Furthermore, all three membranes seeded with chondrocytes formed mature cartilage-like tissue after 8 weeks of in vivo culture, but satisfactory homogeneous cartilage regeneration was only achieved with the F9P1 group. The current results demonstrated that the electrospun FC/PCL membrane is a promising scaffold for cartilage regeneration and that the F9P1 group might represent a relatively suitable ratio. The research models established in the current study provide detailed information for the regeneration of cartilage and other tissue based on electrospun FC/PCL membranes.

Decellularized cartilage matrix scaffolds with laser-machined micropores for cartilage regeneration and articular cartilage repair.

Decellularized allogeneic and xenogeneic articular cartilage matrix scaffolds (CMS) are considered ideal scaffolds for cartilage regeneration owing to their heterogeneous architecture, and biochemical and biomechanical properties of native articular cartilage. However, the dense structure of the articular cartilage extracellular matrix, particularly the arrangement of collagen fibers, limits cellular infiltration, leading to poor cartilage regeneration. In addition, the incomplete removal of xenograft cells is associated with immunogenic reaction in the host. To facilitate the migration of chondrocytes into scaffolds and the rate of decellularization processing, we applied a carbon dioxide laser technique to modify the surface of porcine CMS while retaining major properties of the scaffold. By optimizing the laser parameters, we introduced orderly, lattice-arranged conical micropores of suitable depth and diameter onto the cartilage scaffold surface without affecting the cartilage shape or mechanical properties. We found that laser-modified CMS (LM-CMS) could enhance the degree of decellularization and were conducive to cell adhesion, as compared with the intact CMS. Decellularized scaffolds were seeded with rabbit-derived chondrocytes and cultured for 8 weeks in vitro. We found that cell-scaffold constructs formed cartilage-like tissue within the micropores and on the scaffold surface. In vivo, we found that cell-scaffold constructs subcutaneously implanted into the flanks of nude mice formed ivory-white neocartilage with high contents of DNA and cartilage matrix components, as well as good mechanical strength as compared with native CMS. Furthermore, scaffolds combined with autogenous chondrocytes induced neocartilage and better structural restoration at 8 weeks after transplantation into rabbit knee articular cartilage defects. In conclusion, decellularized xenogeneic CMS with laser-machined micropores offers an ideal scaffold with high fidelity for the functional reconstruction of articular cartilage.

Porous decellularized trachea scaffold prepared by a laser micropore technique.

Rapid development of tissue engineering technology provides new methods for tracheal cartilage regeneration. However, the current lack of an ideal scaffold makes engineering of trachea cartilage tissue into a three-dimensional (3-D) tubular structure a great challenge. Although a decellularized trachea matrix (DTM) has become a recognized scaffold for trachea cartilage regeneration, it is difficult for cells to detach from or penetrate the matrix because of its non-porous structure. To tackle these problems, a laser micropore technique (LMT) was applied in the current study to enhance trachea sample porosity, and facilitate decellularizing treatment and cell ingrowth. Furthermore, after optimizing LMT and decellularizing treatment parameters, LMT-treated DTM (LDTM) retained its natural tubular structure with only minor extracellular matrix damage. Moreover, compared with DTM, the current study showed that LDTM significantly improved the adherence rate of cells with perfect cell biocompatibility. Moreover, the optimal implantation cell density for chondrogenesis with LDTM was determined to be 1 × 108 cells/ml. Collectively, the results suggest that the novel LDTM is an ideal scaffold for trachea tissue engineering.

Histone deacetylase inhibitor valproic acid (VPA) promotes the epithelial mesenchymal transition of colorectal cancer cells via up regulation of Snail.

Histone deacetylase inhibitors (HDACIs) have been shown to have antiproliferative activity through cell-cycle arrest, differentiation, and apoptosis in colorectal cancer (CRC) cells. Our present study revealed that one HDAC inhibitor, valproic acid (VPA), can obviously promote in vitro motility of HCT-116 and SW480 cells. VPA treatment significantly down regulates the expression of epithelial markers E-Cadherin (E-Cad) and Zona occludin-1(ZO-1) while up regulates the mesenchymal markers Vimentin (Vim) and N-cadherin (N-Cad), suggesting that VPA can trigger the epithelial-mesenchymal transition (EMT) of CRC cells. VPA treatment significantly increases the expression and nuclear localization of Snail, the key transcription factors of EMT. Snail knockdown by siRNAs obviously reverses VPA induced EMT of HCT-116 and SW480 cells. Further, VPA can decrease the ubiquitination, increase the acetylation, and then elevate the stabilization of Snail. VPA also increases the phosphorylation of Akt/GSK-3ß. The inhibitor of PI3K/Akt, LY2994002, significantly attenuates VPA induced phosphorylation of Akt and GSK-3ß and up regulation of Snail and Vim. Collectively, our data reveal that VPA can trigger the EMT of CRC cells via up regulation of Snail through AKT/GSK-3ß signals and post-transcriptional modification. It suggests that more attention should be paid when VPA used as a new anticancer drug for CRC patients.

Mitochondrial COI/tRNASer(UCN) G7444A mutation may be associated with aminoglycoside-induced and non-syndromic hearing impairment.

Mutations in mitochondrial DNA (mtDNA) have been reported to have important roles in aminoglycoside-induced hearing impairment; however, the underlying molecular mechanisms have remained largely elusive. The current study presented a case of a Chinese patient with maternally inherited aminoglycoside-induced hearing impairment. A profound hearing impairment was identified by clinical evaluation; furthermore, analysis of the mitochondrial genome sequence of the patient revealed the presence of an A1555G mutation in the 12S rRNA as well as a G7444A mutation in the COI/tRNASer(UCN) gene. As the G7444A mutation is highly conserved between various species, it may be a modifying factor with regard to the pathological effects of the A1555G mutation.

Distributions and Types of Multidrug-Resistant Acinetobacter baumannii in Different Departments of a General Hospital.

BACKGROUND: Acinetobacter baumannii is the most prevalent strain in hospitals and different clinical departments. OBJECTIVES: The current study aimed to investigate the genetic characteristics and resistance mechanisms of A. baumannii isolated from clinical samples in Shaoxing people's hospital affiliated to Zhejiang University, Shaoxing, China. PATIENTS AND METHODS: Acinetobacter baumannii strains were isolated from blood, phlegm and skin of the patients hospitalized in different departments as respiratory medicine, plastic surgery and intensive care unit (ICU). Multilocus sequence typing (MLST) was used to characterize the isolates. Kirby-Bauer test was used to evaluate antibiotic resistance of the bacteria. The expression of resistance inducing genes was detected by reverse transcription polymerase chain reaction (RT-PCR). The results were analyzed and compared. RESULTS: Two bacterial types, ST208, and ST218, were identified in all 140 samples. The ST208 mainly came from ICU and department of respiratory medicine, while ST218 from department of plastic surgery; 70.21% of ST208 and 84.78% of ST218 were carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-susceptible Acinetobacter baumannii (CSAB), respectively. Multidrug-resistance genes in CRAB isolated from the hospital mainly included, oxa-23, oxa-5, intl 1 and qaceΔ1-sul 1. Besides, the highest and lowest antibiotic resistance was observed in the strains isolated from blood samples and wounds, respectively. CONCLUSIONS: The distribution of AB varies in different clinical departments and samples. In the hospital under study, the main types of AB were ST208 and ST218. The genes which affect the ability of antibiotic-resistance were oxa-23, oxa-51, intl 1 and qaceΔ1-sul 1.

Ethanol chemiresistor with enhanced discriminative ability from acetone based on Sr-doped SnO2 nanofibers.

We demonstrated a new metal oxides based chemiresistor (MOC), which exhibits fast response/recovery behavior, large sensitivity, and good selectivity to ethanol, enabled by Sr-doped SnO2 nanofibers via simple electrospinning and followed by calcination. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectra (XPS) were carefully used to characterize their morphology, structure, and composition. The ethanol sensing performances based on Sr-doped SnO2 nanofibers were investigated. Comparing with the pristine SnO2 nanofibers, enhanced ethanol sensing performances (more rapid response/recovery behavior and larger response values) have been achieved owing to the basic SnO2 surface caused by Sr-doping, whereas the acetone sensing performances have been weakened. Thus, good discriminative ability to ethanol from acetone has been realized. Additionally, Sr-doped SnO2 nanofibers also exhibit good selectivity.

Association between rs4938723 functional polymorphism in the promoter region of miR-34b/c gene and cancer risk.

Genetic polymorphism of miR-34b/c gene is a candidate factor for attributing predisposition to carcinoma. However, results of mounting studies, concerning association of miR-34b/c gene rs4938723 with risk of cancer, present contradictory results. Therefore, a meta-analysis was performed to systematically assessment the possible association between them. The overall results of meta-analysis indicate a significant association was only observed between rs4938723 and cancer risk in genotype model (P(h)=0.203, OR=1.09, 95% CI=1.01-1.70 for CT vs. TT). After stratifying by ethnicity and cancer type, genotype CT of rs4938723 was significantly association with an increased cancer risk in Asian population (P(h)=0.187, OR=1.10, 95%CI=1.01-1.20), allele C and genotype CT were significantly positive associated with hepatocellular cancer (P(h)=0.113, OR=1.11, 95%CI=1.01-1.23 for C vs. T; P(h)=0.121, OR=1.19, 95%CI=1.03-1.37 for CT vs. TT), but rs4938723 was negative associated with risk of colorectal cancer (P(h)=0.342, OR=0.66, 95%CI=0.47-0.92 for CC vs. TT; P(h)=0.519, OR=0.67, 95%CI=0.49-0.93 for CC vs. CT/TT; P(h)=0.443, OR=0.71, 95%CI=0.51-0.99 for CC/TT vs. CT). These findings suggested that rs4938723 was a susceptible locus only for hepatocellular cancer and colorectal cancer.

[Xu Ren's Zhen jiu jing yan fang (Experiential recipe on acupuncture and moxibustion) and its spread].

The book, Zhen jiu jing yan fang (Experiential Recipe on Acupuncture and Moxibustion), written by Xu Ren, an imperial physician of Korea was completed in the 4th year of Renzu emperor (1644), and was an important work for the history of Korean acupuncture and moxibustion. However, there were mistakes on its writing date as described in the books of acu - moxibustion history in former reports. The portion of Mian xue tang zhen jiu ji cheng (Mianxuetang's Complete Work of Acupuncture and Moxibustion) universally recognized to be unique, was plagiarized from Zhen jiu jing yan fang.