Targeted synthesis of two super-complex zeolites with embedded isoreticular structures

A novel structural coding approach combining structure solution, prediction, and the targeted synthesis of new zeolites with expanding complexity and embedded isoreticular structures was recently proposed. Using this approach, the structures of two new zeolites in the RHO family, PST-20 and PST-25, were predicted and synthesized. Herein, by extending this approach, the next two higher generation members of this family, PST-26 and PST-28, have been predicted and synthesized. These two zeolites have much larger unit cell volumes (422 655 Å3 and 614 912 Å3, respectively) than those of the lower generations. Their crystallization was confirmed by a combination of both powder X-ray and electron diffraction techniques. Aluminate and water concentrations in the synthetic mixture were found to be the two most critical factors influencing the structural expansion of embedded isoreticular zeolites under the synthetic conditions studied herein.PostprintPostprintPeer reviewe

A secure SNP panel scheme using homomorphically encrypted K-mers without SNP calling on the user side

Background Single Nucleotide Polymorphism (SNP) in the genome has become crucial information for clinical use. For example, the targeted cancer therapy is primarily based on the information which clinically important SNPs are detectable from the tumor. Many hospitals have developed their own panels that include clinically important SNPs. The genome information exchange between the patient and the hospital has become more popular. However, the genome sequence information is innate and irreversible and thus its leakage has serious consequences. Therefore, protecting ones genome information is critical. On the other side, hospitals may need to protect their own panels. There is no known secure SNP panel scheme to protect both. Results In this paper, we propose a secure SNP panel scheme using homomorphically encrypted K-mers without requiring SNP calling on the user side and without revealing the panel information to the user. Use of the powerful homomorphic encryption technique is desirable, but there is no known algorithm to efficiently align two homomorphically encrypted sequences. Thus, we designed and implemented a novel secure SNP panel scheme utilizing the computationally feasible equality test on two homomorphically encrypted K-mers. To make the scheme work correctly, in addition to SNPs in the panel, sequence variations at the population level should be addressed. We designed a concept of Point Deviation Tolerance (PDT) level to address the false positives and false negatives. Using the TCGA BRCA dataset, we demonstrated that our scheme works at the level of over a hundred thousand somatic mutations. In addition, we provide a computational guideline for the panel design, including the size of K-mer and the number of SNPs. Conclusions The proposed method is the first of its kind to protect both the users sequence and the hospitals panel information using the powerful homomorphic encryption scheme. We demonstrated that the scheme works with a simulated dataset and the TCGA BRCA dataset. In this study, we have shown only the feasibility of the proposed scheme and much more efforts should be done to make the scheme usable for clinical use.This research is supported by National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT (No. NRF-2017M3C4A7065887), The Collaborative Genome Program for Fostering New Post-Genome Industry of the National Research Foundation (NRF) funded by the Ministry of Science and ICT (MSIT) (No. NRF-2014M3C9A3063541), A grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI15C3224), and Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (B0717-16-0098, Development of homomorphic encryption for DNA analysis and biometry authentication). The publication cost will be paid by the Seoul National University Office of Research

Synthesis and structure of a CDO zeolite precursor with a high Al content

A new CDO zeolite precursor (PreCDO) with a Si/Al ratio of 8.7, the lowest among the layered precursors of this channel-based small-pore zeolite reported so far, has been synthesized using tetraethylammonium (TEA(+)) and tetramethylammonium (TMA(+)) ions in fluoride media. However, both the elemental analysis and C-13 MAS NMR results reveal the presence of TEA(+) only in PreCDO, although this layered phase did not crystallize without TMA(+) or F- present. The structure of PreCDO solved by a combination of synchrotron X-ray diffraction Rietveld analysis and computational modeling shows that the ferrierite (fer) layers of PreCDO are stacked with an interlayer distance of 2.7 angstrom. Its calcination led to a condensation along the a-axis, yielding a highly crystalline CDO zeolite.11Nsciescopu

Circular radio-frequency electrode with MEMS temperature sensors for laparoscopic renal sympathetic denervation

IEEEObjective: Laparoscopic renal denervation (LRDN) ablates sympathetic nerves on the outer wall of a renal artery to treat autonomic nervous system disorders such as hypertension and arrhythmia. Here, we developed a new circular radio frequency (RF) electrode for LRDN using micro-electro-mechanical systems (MEMS) technology. Methods: The electrode consists of a parallel bipolar MEMS electrode, two MEMS thermocouples, and a shape-memory alloy (SMA) substrate. The electrode is automatically wrapped and unwrapped under actuation controlled by the heat generated by RF energy on the electrodetissue interface. The electrode was designed through a computational simulation analysis, and its actuation and temperature-sensing performance were tested in laboratory experiments and a porcine animal study. Results: In an in-vivo study of porcine renal arteries, the electrode could automatically wrap and unwrap around an artery during LRDN. The bipolar MEMS electrode required 13 Vrms for heat generation up to 60 C, while the two MEMS thermocouples reliably measured the temperature without noise signals (a temperature coefficient of 38.3 or 38.5 V/C and an accuracy of 0.44 or 0.49 C). As revealed in a histological analysis using hematoxylin and eosin staining and Massons trichrome staining, the renal artery was intact after LRDN. Conclusion: The circular RF electrode improves the safety of LRDN by reliably measuring the electrode temperature of the electrode during RDN and enhances the effectiveness of LRDN by reducing the complicated manipulations of the surgical instrument. Significance: The developed circular RF electrode will pave the way for LRDN treatment of autonomic nervous system disorders.11Nsciescopu

Two Aluminophosphate Molecular Sieves Built from Pairs of Enantiomeric Structural Building Units

Herein we report the synthesis and structures of two new small-pore aluminophosphate molecular sieves PST-13 and PST-14 with mutually connected 8-ring channels. The structure of PST-13, synthesized using diethylamine as an organic structure-directing agent, contains penta-coordinated framework Al atoms bridged by hydroxy groups and thus edge-sharing 3- and 5-rings. Upon calcination, PST-13 undergoes a transformation to PST-14 with loss of bridging hydroxy groups and occluded organic species. The structures of both materials consist nonjointly of pairs of previously undiscovered 1,5- and 1,6-open double 4-rings (d4rs) which are mirror images of each other. We also present a series of novel chemically feasible hypothetical structures built from 1-open d4r (sti) or 1,3-open d4r (nsc) units, as well as from these two enantiomeric structural building units.11Nsciescopu

Elastomeric Angled Microflaps with Reversible Adhesion for Transfer-Printing Semiconductor Membranes onto Dry Surfaces

Recent research for unconventional types of electronics has revealed that it is necessary to transfer-print high-performance microelectronic devices onto diverse surfaces, including flexible or stretchable surfaces, to relieve mechanical constraints associated with conventional rigid electronics. Picking up and placing ultrathin microdevices without damage are critical procedures for the successful manufacture of various types of unconventional electronics. This paper introduces elastomeric angled microflaps that have reversible adhesion; i.e., they generate higher adhesion for picking up and low adhesion for printing because of their structural shapes and viscoelastic material properties. The microstructured stamp, fabricated in relatively simple ways, enables simultaneous transfer-printing of multiple silicon membranes that have irregular shapes in sizes ranging from micrometer to millimeter scales. Mechanical characterizations by experiment reveal optimal parameters for picking up and placing ultrathin membranes on a programmable custom-built microstage. Further refinement of the structures and materials should be useful for many applications requiring the microassembly of multiple semiconductor membranes in diverse shapes and sizes on dry surfaces without the aid of liquid adhesives

Microelectrical Impedance Spectroscopy for the Differentiation between Normal and Cancerous Human Urothelial Cell Lines: Real-Time Electrical Impedance Measurement at an Optimal Frequency

Purpose. To distinguish between normal (SV-HUC-1) and cancerous (TCCSUP) human urothelial cell lines using microelectrical impedance spectroscopy (μEIS). Materials and Methods. Two types of μEIS devices were designed and used in combination to measure the impedance of SV-HUC-1 and TCCSUP cells flowing through the channels of the devices. The first device (μEIS-OF) was designed to determine the optimal frequency at which the impedance of two cell lines is most distinguishable. The μEIS-OF trapped the flowing cells and measured their impedance at a frequency ranging from 5 kHz to 1 MHz. The second device (μEIS-RT) was designed for real-time impedance measurement of the cells at the optimal frequency. The impedance was measured instantaneously as the cells passed the sensing electrodes of μEIS-RT. Results. The optimal frequency, which maximized the average difference of the amplitude and phase angle between the two cell lines (p<0.001), was determined to be 119 kHz. The real-time impedance of the cell lines was measured at 119 kHz; the two cell lines differed significantly in terms of amplitude and phase angle (p<0.001). Conclusion. The μEIS-RT can discriminate SV-HUC-1 and TCCSUP cells by measuring the impedance at the optimal frequency determined by the μEIS-OF