Naturally Dried Graphene Aerogels with Superelasticity and Tunable Poisson's Ratio

A novel natural drying (ND) strategy for low-cost and simple fabrication of graphene aerogels (GA) is highlighted. The as-formed NDGA exhibit ultralarge reversible compressibility (99%) and tunable Poisson's ratio behaviors (−0.30 < ν < 0.46), which suggests promising applications as soft actuators, soft robots, sensors, deformable electronic devices, drug release, thermal insulator, and protective materials.

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Spoofing voice verification systems with statistical speech synthesis using limited adaptation data

Publication date: Available online 5 September 2016
Source:Computer Speech & Language
Author(s): Ali Khodabakhsh, Amir Mohammadi, Cenk Demiroglu
State-of-the-art speaker verification systems are vulnerable to spoofing attacks using speech synthesis. To solve the issue, high-performance synthetic speech detectors (SSDs) for known attack methods have been proposed recently. Here, as opposed to developing new detectors, we investigate new attack strategies. Investigating new techniques that are specifically tailored for spoofing attacks that can spoof the voice verification system and are difficult to detect is expected to increase the security of voice verification systems by enabling the development of better detectors. First, we investigated the vulnerability of an i-vector based verification system to attacks using statistical speech synthesis (SSS) with a particular focus on the case where the attacker has only a very limited amount of data from the target speaker. Even with a single adaptation utterance, the false alarm rate was found to be %23. Still, SSS-generated speech is easy to detect [1, 2] which dramatically reduces its effectiveness. For more effective attacks with limited data, we propose a hybrid statistical/concatenative synthesis approach and show that hybrid synthesis significantly increases the false alarm rate in the verification system compared to the baseline SSS method. Moreover, proposed hybrid synthesis makes detecting synthetic speech more difficult compared to SSS even when very limited amount of original speech recordings are available to the attacker. To further increase the effectiveness of the attacks, we propose a linear regression method that transforms synthetic features into more natural features. Even though the regression approach is more effective at spoofing the detectors, it is not as effective as the hybrid synthesis approach in spoofing the verification system. An interpolation approach is proposed to combine the linear regression and hybrid synthesis methods which is shown to provide the best spoofing performance in most cases.



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TCGA Data Leveraged for Developing FDA-Designated Breakthrough Therapy

LOXO-101, a promising new drug developed by Loxo Oncology, received FDA breakthrough therapy designation in July, 2016, for the treatment of metastatic cancers with tropomyosin receptor kinase (TRK) fusions. Using publically available data, including those from The Cancer Genome Atlas (TCGA), Loxo Oncology identified TRK fusions as prime targets for drug development, says Loxo Oncology's Chief Executive Officer, Josh Bilenker, M.D.

"We found that TCGA efforts had contributed to a better understanding of the clinical settings in which TRK fusions occur. Also, TCGA data helped confirm that TRK fusions were typically present in the absence of other known oncogenic drivers," said Dr. Bilenker. "Taken together, these insights helped point the way to clinical settings we might not have considered, while increasing our confidence that TRK fusions were likely to be oncogenic drivers susceptible to therapeutic intervention."

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Accuracy of Tumor Sizing in Breast Cancer: A Comparison of Strain Elastography, 3-D Ultrasound and Conventional B-Mode Ultrasound with and without Compound Imaging

Publication date: Available online 3 September 2016
Source:Ultrasound in Medicine & Biology
Author(s): Angrit Stachs, Alexander Pandjaitan, Annett Martin, Johannes Stubert, Steffi Hartmann, Bernd Gerber, Änne Glass
The objective of this study was to compare the accuracy of strain elastography (SE), 3-D ultrasound (US), B-mode US with compound imaging (CI) and B-mode US without compound imaging for lesion sizing in breast cancer. The prospective study included 93 patients with invasive breast cancer. The largest tumor diameters measured by B-mode US, B-mode US with CI, SE and 3-D US were compared in Bland–Altman plots versus pathology as reference. A general linear model repeated measures (GLM Rep) was applied to investigate factors influencing tumor sizing. All methods underestimated pathologic size, with SE (−0.08 ± 7.7 mm) and 3-D US (−1.4 ± 6.5 mm) having the smallest mean differences from pathology. Bland–Altman plots revealed that B-mode US, B-mode US with CI and 3-D US systematically underestimated large tumor sizes, and only SE was technically comparable to pathology. The study indicates that sonographic underestimation of tumor size occurs mainly in tumors >20 mm; in this subgroup, SE is superior to other ultrasound methods.



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Effect of Low-Intensity Pulsed Ultrasound after Mesenchymal Stromal Cell Injection to Treat Osteochondral Defects: An In Vivo Study

Publication date: Available online 3 September 2016
Source:Ultrasound in Medicine & Biology
Author(s): Shoki Yamaguchi, Tomoki Aoyama, Akira Ito, Momoko Nagai, Hirotaka Iijima, Junichi Tajino, Xiangkai Zhang, Kiyan Wataru, Hiroshi Kuroki
We investigated the effect of low-intensity pulsed ultrasound (LIPUS) treatment combined with mesenchymal stromal cell (MSC) injection for cartilage repair and subchondral bone reconstitution for treatment of osteochondral defects. An osteochondral defect was created on both femur grooves of Wistar rats. Four weeks later, bone marrow MSCs were injected into the right knee joint. The rats were divided into two intervention groups: without or with LIPUS irradiation. Cartilage repair was evaluated histologically based on the Wakitani cartilage repair score. Subchondral bone reconstitution was evaluated as bone volume (BV)/tissue volume (TV) by micro-computed tomography analysis. MSC injection improved the cartilage repair score, and LIPUS irradiation improved BV/TV. Combination treatment promoted both cartilage repair and BV/TV improvement. Thus, MSC injection combined with LIPUS irradiation is more effective than either treatment alone in promoting concurrent cartilage repair and subchondral reconstitution.



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Short Hairpin RNA Knockdown of Connective Tissue Growth Factor by Ultrasound-Targeted Microbubble Destruction Improves Renal Fibrosis

Publication date: Available online 3 September 2016
Source:Ultrasound in Medicine & Biology
Author(s): Shuping Wei, Chaoli Xu, Joshua J. Rychak, Alice Luong, Yu Sun, Zhijian Yang, Mingxia Li, Chunrui Liu, Ninghua Fu, Bin Yang
The purpose of this study was to evaluate whether ultrasound-targeted microbubble destruction transfer of interfering RNA against connective tissue growth factor (CTGF) in the kidney would ameliorate renal fibrosis in vivo. A short hairpin RNA (shRNA) targeting CTGF was cloned into a tool plasmid and loaded onto the surface of a cationic microbubble product. A unilateral ureteral obstruction (UUO) model in mice was used to evaluate the effect of CTGF knockdown. Mice were administered the plasmid-carrying microbubble intravenously, and ultrasound was applied locally to the obstructed kidney. Mice undergoing a sham UUO surgery and untreated UUO mice were used as disease controls, and mice administered plasmid alone, plasmid with ultrasound treatment and microbubbles and plasmid without ultrasound were used as treatment controls. Mice were treated once and then evaluated at day 14. CTGF in the kidney was measured by quantitative reverse transcription polymerase chain reaction and Western blot. Expression of CTGF, transforming growth factor β1, α smooth muscle actin and type I collagen in the obstructed kidney was evaluated by immunohistochemistry. The cohort treated with plasmid-carrying microbubbles and ultrasound exhibited reduced mRNA and protein expression of CTGF (p < 0.01). Furthermore, CTGF gene silencing decreased the interstitial deposition of transforming growth factor β1, α smooth muscle actin and type I collagen as assessed in immunohistochemistry, as well as reduced renal fibrosis in pathologic alterations (p < 0.01). No significant changes in target mRNA, protein expression or disease pathology were observed in the control cohorts. A single treatment of ultrasound-targeted microbubble destruction is able to deliver sufficient shRNA to inhibit the expression of CTGF and provide a meaningful reduction in disease severity. This technique may be a potential therapy for treatment of renal fibrosis.



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Expanding Role of Contrast-Enhanced Ultrasound in Guidance and Monitoring of Percutaneous Thermal Ablation

Publication date: Available online 3 September 2016
Source:Ultrasound in Medicine & Biology
Author(s): Chiara De Angelis, Giovanni Mauri




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