Negative LC Research Articles

23‐1: Invited Paper: Research on High Contrast Ratio for ADS Products

We have achieved CR 3000:1 for 4K ADS products including MNT & TV, while balancing such specifications of GTG, transmittance, driving voltage, color gamut etc. In this article, systematic analysis have been conducted and conclusions on the influences between high CR and negative LC, RGB, PVX and high‐collimation BLU have been drawn.

Benzoxazole-terminated liquid crystals with large birefringence and negative dielectric anisotropy

We synthesized heterocyclic liquid crystals with large birefringence and negative dielectric anisotropy, namely, 5–4-(2-(4-(alkoxy)phenyl)-2,3-difluorophenyl)benzo(d)oxazole derivatives (nPFO). These compounds display enantiotropic nematic mesophases with wide mesophase range of 45.9–84.0 °C (heating process) and 61.3–119.6 °C (cooling process). Compared with reference analogues of traditional benzoxazole compound 6PFB with different orientation of benzoxazole-terminated structure, the compounds nPFO roughly give lower melting points and clearing points because of their increased dihedral angle. Meanwhile, compounds nPFO show obviously large birefringence (Δn, 0.28–0.39 and 0.39–0.48 for experimental measurement and DFT theoretical calculation, respectively) due to the enhanced π-conjugation caused by the ethynyl bridge group in molecules. Benefitting from the larger perpendicular dipole moments and orientation angles, nPFO displays negative dielectric anisotropy (Δɛ) ranging from −3.60 to −4.10. These compounds can endow a commercial negative LC mixture the larger Δn and higher values of figure of merit, suggesting they are suitable dopant to further improve the performance of some commercial LC mixtures.

Cell type and stage specific transcriptional, chromatin and cell-cell communication landscapes in the mammary gland

The mammary gland (MG) is composed of three main epithelial lineages, the basal cells (BC), the estrogen receptor (ER) positive luminal cells (ER+ LC), and the ER negative LC (ER− LC). Defining the cell identity of each lineage and how it is modulated throughout the different stages of life is important to understand how these cells function and communicate throughout life. Here, we used transgenic mice specifically labelling ER+ LC combined to cell surface markers to isolate with high purity the 3 distinct cell lineages of the mammary gland and defined their expression profiles and chromatin landscapes by performing bulk RNAseq and ATACseq of these isolated populations in puberty, adulthood and mid-pregnancy. Our analysis identified conserved genes, ligands and transcription factor (TF) associated with a specific lineage throughout life as well as genes, ligands and TFs specific for a particular stage of the MG. In summary, our study identified genes and TF network associated with the identity, function and cell-cell communication of the different epithelial lineages of the MG at different stages of life.

Transpiration rates decline under limited moisture supply along hillslopes in a humid karst terrain

Topographic positions can mediate subsurface water availability, but its effects on tree transpiration are controversial. In humid karst regions, climax forests are usually not limited by moisture supply, even at the summit, through absorbing water from deep layers. However, little is known on the transpiration pattern and its limiting factor on the shrubland widely distributed along the karst hillslopes. In the current study, Rhus chinensis, a widely spread constructive species in natural restoration was selected. Meteorological factors, 0–300 cm soil–epikarst moisture, sap flow, and root water uptake were studied during an entire growing season to assess how hillslope positions affected transpiration. We found the mean water content in uphill was only around 60 % of that in downhill, indicating a contrasting water supply along the slope. However, there were no significant differences in the xylem isotopic composition and lc–excess which suggested the similar water uptake strategies in both uphill and downhill. R. chinensis primarily relied on the soil water rather than epikarst water (groundwater) along the hillslope because of the MixSIAR model results and more negative lc–excess values (−13.18 ‰). R. chinensis exhibited decreases of nearly half in the transpiration rate and amount in uphill compared to those in downhill. In downhill with sufficient water availability, transpiration followed the variation in atmospheric water demand. In uphill, a poor moisture supply limited tree transpiration and its response to atmospheric water demand. Our findings revealed that the early successional species did not entirely depend on atmospheric water demand, absorbing deep epikarst water as the mature forest. The transpiration rates of those species declined by nearly half to adapt to the water–limited environment along the hillslope in the humid karst region. This study can contribute to the evaluation of eco–hydrological functions during natural restoration.

Broadband Doherty Power Amplifier Using Short Ended λ/4 Transmission Lines Based on the Analysis of Negative Characteristic Impedance

This paper presents a broadband Doherty power amplifier (DPA) using quarter-wavelength ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> /4) transmission lines with negative characteristic impedance. In conventional DPA designs, the load modulation network is frequency-dependent, leading to bandwidth limitation at the back-off power region. In this design, by integrating two <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> /4 transmission lines with negative characteristic impedance into the main and auxiliary branches, the impedance at the back-off power can be manipulated to maintain high efficiency at back-off power over a wide frequency range. Thus, the operational bandwidth is extended. In circuit realization, the two negative characteristic impedance <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> /4 transmission lines are replaced by paralleled negative LC components. Then, the negative capacitor is combined into the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $ </tex-math></inline-formula> -shaped impedance matching network, while the negative inductor is eliminated by introducing Norton transformation. For verification, a broadband DPA with a fractional bandwidth of 108.6% from 0.8 to 2.7 GHz is implemented. The measured saturated output power is 41.8-44 dBm. The saturated and 6-dB back-off power drain efficiencies are 47.6%-84.4% and 39.5%- 52%, respectively. A 20-MHz LTE modulated signal with peak-to- average power ratio (PAPR) of 7.5 dB is also applied to measure the fabricated DPA. After digital predistortion, the adjacent channel leakage ratio (ACLR) better than −45.35 dBc is achieved, and the measured average efficiency is higher than 40% within the operating band.

34‐6: Invited Paper: High Image Quality of 8K TV LCDs with Negative LC

ADS display mode with positive LC mixture has been widely used in TV and other large size LCD products. After years of technical iterations, positive LC mixture have approached the material limit in terms of transmittance, contrast ratio and so on. In order to improve image quality continuously, especially for high end 8K TV products, we have developed a total negative LC (N‐LC) solution with rubbing alignment process. This total solution includes high CR negative LC material, rubbing PI material and process, and high‐transparent pixel ITO design. Based on this total solutions, TR has been increased by 30% for 8K LCDs. CR has been increased from 1400 to 2500:1 for 8K and 3000:1 for 4K LCDs. Meanwhile, this solution keep response time (RT) and reliability of image sticking (I/S) can meet the regular specifications.

34‐4: Invited Student Paper: UBplus/UB‐FFS‐Premium Performance for Liquid‐Crystal TV and IT Displays

Premium displays that offer outstanding characteristics are becoming more important in liquid crystal display market. Globally, researchers are looking for ways to improve contrast, transmittance, viewing angle dependency, resolution and switching speed while keep the high reliability level of liquid crystal devices. UB (Ultra Bright)‐technology (UBplus and UBFFS) can increase panel transmittance by using negative dielectric anisotropy LC mixtures compared with traditional FFS Mode, supporting higher resolution devices. In this paper we demonstrate the advantage of UB‐LC technology for TV as well as IT applications and summarize the recent developments of such liquid crystal mixtures in terms of contrast, switching speed and reliability.

A Quantitative LC-MS/MS Method for the Detection of 16 Synthetic Cathinones and 10 Metabolites and Its Application to Suspicious Clinical and Forensic Urine Samples.

Background: Synthetic cathinones currently represent one of the most predominant (sub)-classes of new psychoactive substance (NPS) in illicit drug markets. Despite the increased concerns caused by the constant introduction of new analogues, these drugs are not commonly assayed in routine drug testing procedures and may not be detected in standard screening procedures. This study presents a validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the detection and quantification of 16 synthetic cathinones and 10 metabolites in human urine. Methods: The method was validated for all analytes using published guidelines. The evaluated parameters achieved acceptable values according to the set criteria. Potential abuse of synthetic cathinones was investigated in suspicious urine samples from Saudi Arabia originating from workplace drug testing, pre-employment and Accident & Emergency (A&E). Such samples generated a presumptive positive immunoassay for amphetamine; however, they yielded a negative LC–MS/MS confirmation for this analyte, following the recommended cutoff values of Substance of Abuse and Mental Health Services Administration (SAMHSA) guidelines. Results: 5.8% of the analyzed samples were found to contain at least one target analyte, namely mephedrone and N-ethylpentylone, as well as their dihydro-metabolites. The results also revealed polydrug use with the synthetic cathinones being present together with other classical stimulant drugs. Conclusions: This is the first report of NPS use in Saudi Arabia with respect to designer stimulant drugs. Confirmatory urine analyses for suspicious stimulant use should extend beyond classical stimulants to cover a broad range of NPSs and their metabolites in order to report any otherwise potentially undetected/new analyte.

47.4: Study on the flicker shift in FFS TFT‐LCD Mode

Based on FFS TFT‐LCD panel, flicker shift with different cell materials was investigated, including lighting effect on the shift value with backlight on and off. Negative LC shifts much smaller than positive LC, even after reliability test. High resistance PI A shows a better result less than 1dB, while the low resistance PI B shift about 8dB, including introduce a DC voltage when lighting is on. However this DC can be compensated mainly by DC caused by the flexoelectric effect, which proposed a method to reduce flicker shift value with PI B. The DC caused by the flexoelectric effect is further improved by the asymmetric voltage‐transmittance (VT) curve. These studies can give the guidance for improving the flicker shift phenomenon in FFS mode.

P‐155: Study on Fast Response Pixel Model for VR HMD Application with Flexoelectric Effect Comparison

Fast response liquid crystal display is needed in recent AR VR application. In this paper, we propose a vase shape slit pixel structure and study the flexoelectric effect in different pixel structure for AR HMD application. LC behavior in positive and negative LC with and without flexoelectric effect was discussed.

A surrogate analyte-based liquid chromatography-tandem mass spectrometry method for the determination of endogenous cyclic nucleotides in rat brain

A robust high-performance liquid chromatography tandem mass spectrometry (LC–MS/MS) assay was developed and qualified for the measurement of cyclic nucleotides (cNTs) in rat brain tissue. Stable isotopically labeled 3′,5′-cyclic adenosine-13C5 monophosphate (13C5-cAMP) and 3′,5′-cyclic guanosine-13C,15N2 monophosphate (13C15N2-cGMP) were used as surrogate analytes to measure endogenous 3′,5′-cyclic adenosine monophosphate (cAMP) and 3′,5′-cyclic guanosine monophosphate (cGMP). Pre-weighed frozen rat brain samples were rapidly homogenized in 0.4M perchloric acid at a ratio of 1:4 (w/v). Following internal standard addition and dilution, the resulting extracts were analyzed using negative ion mode electrospray ionization LC–MS/MS. The calibration curves for both analytes ranged from 5 to 2000ng/g and showed excellent linearity (r2>0.996). Relative surrogate analyte-to-analyte LC–MS/MS responses were determined to correct concentrations derived from the surrogate curves. The intra-run precision (CV%) for 13C5-cAMP and 13C15N2-cGMP was below 6.6% and 7.4%, respectively, while the inter-run precision (CV%) was 8.5% and 5.8%, respectively. The intra-run accuracy (Dev%) for 13C5-cAMP and 13C15N2-cGMP was <11.9% and 10.3%, respectively, and the inter-run Dev% was <6.8% and 5.5%, respectively. Qualification experiments demonstrated high analyte recoveries, minimal matrix effects and low autosampler carryover. Acceptable frozen storage, freeze/thaw, benchtop, processed sample and autosampler stability were shown in brain sample homogenates as well as post-processed samples. The method was found to be suitable for the analysis of rat brain tissue cAMP and cGMP levels in preclinical biomarker development studies.

Submillisecond-response liquid crystal for high-resolution virtual reality displays.

We report a vertically-aligned liquid crystal display (LCD) device with submillisecond response time, high transmittance, and low operation voltage. The top substrate has a common electrode, while the bottom substrate consists of hole-patterned fringing-field-switching (FFS) pixel electrodes. A negative dielectric anisotropy LC is employed. In the voltage-on state, the LC directors are reoriented by the fringing fields surrounding the hole area and by the longitudinal and fringe fields outside the hole area. After design optimization, we are able to achieve 85% peak transmittance under crossed circular polarizers. During the relaxation process, the standing walls exert a strong restoring force, leading to submillisecond gray-to-gray response time. Moreover, this device enables high resolution density because only one thin-film transistor per pixel is needed and the bottom FFS electrode has built-in capacitor. This device is particularly attractive for the emerging virtual reality displays.

Carbon ion therapy (C12) for high-grade malignant salivary gland tumors (MSGTs) of the head and neck: do non-ACCs profit from dose escalation?

PurposeTo evaluate the use of high-dose radiotherapy using carbon ions (C12) on non-adenoid cystic malignant salivary gland tumors (MSGT).Patients and methodsBetween 2009 and 2013, patients with biopsy-proven non-ACC MSGT histologies of the head and neck received a combined regimen of IMRT plus C12 boost. Treatment toxicity (CTC v3), response (RECIST 1.1), control and survival rates were retrospectively analyzed.Results40 patients with pathologically confirmed non-ACC MSGT (T4: 45 %; N+: 40 %; gross residual: 58 %; mucoepidermoid carcinoma (MEC): 45 %; adenocarcinoma: 20 %) were treated with a median of 74 GyE (80 Gy BED). Chemoradiation was given in 5 patients with MEC. Grade III acute toxicity was observed in up to 15 % (mucositis, dermatitis, dysphagia), no higher-grade late toxicity occurred to date. At a follow-up of 25.5 months, LC, and PFS at 2 and 3 years are 81.5 % (LC) and 66.8 % (PFS), OS at 2 and 3 years is 83.6 % and 72.8 %. Most frequent site of disease progression was distant metastasis. Histologic subtype correlated with LC and PFS. Resection status (gross vs microscopic disease) had no significant effect on LC, PFS, or OS.ConclusionThe treatment is well tolerated, no higher grade late effects were observed. Considering the negative pre-selection, LC, PFS and OS are promising. While histology and site of origin significantly influenced control and survival rates, resection status did not, potentially due to the effect of dose escalation.Electronic supplementary materialThe online version of this article (doi:10.1186/s13014-016-0657-z) contains supplementary material, which is available to authorized users.

37-4L:Late-News Paper: Development of a 27-in. 8K x 4K Liquid-Crystal Display Utilizing an InGaZnO TFT Backplane

We have successfully developed 27inch 8K4K Liquid Crystal display by utilizing BCE IGZO (Back Channel Etched InGaZnO) transistor. Its pixel density is 326ppi like smartphone, but the screen size is 27inch, middle class desktop monitor size. And its LCD panel supports 120Hz driving. BCE IGZO-TFT realizes low resistance wiring material because of its low process temperature. Above reason, we can enlarge the screen size to desktop monitor class, remaining smartphone class fine resolution. Also this system contains HDR (High Dynamic Range) driving system, and wide color gamut, by IGZO transistor and Negative LC FFS pixel structure.

Antioxidant activities of Pistacia atlantica extracts modeled as a function of chromatographic fingerprints in order to identify antioxidant markers

Pistacia atlantica belongs to the Anacardiaceae family, and originated from the Atlas mountains of north Africa, which has been employed in traditional medicine for the treatment of various diseases. There are many limitations regarding their activities. The bioactive compounds present in the extract of P. atlantica leaves are not well defined. For these identifications HPLC fingerprint methodology can be used. In the present study, 28 extracts were obtained from male and female leaves of P. atlantica, collected monthly during 6months, in two different growing regions. The total antioxidant capacity (TAC) values of P. atlantica extracts were determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method and the potassium ferricyanide (PFC) reduction method. The fingerprints were pre-treated using several techniques, such as column centering; normalization followed by column centering, and standard normal variate (SNV) transformation followed by column centering; each after initial alignment of the chromatographic profiles with Correlation Optimized Warping (COW). The multivariate calibration methods, Partial Least Squares (PLS) and Orthogonal Projections to Latent Structures (O-PLS), were employed to model TAC. The regression coefficients of the best models were evaluated to indicate the peaks probably responsible for the antioxidant activity. The O-PLS model seems preferable because of its better predictive and describing abilities, and its good interpretability of the contribution of compound peaks to the TAC. Several peaks in the chromatograms were recognized as importantly contributing to the model due to their large regression coefficients. The structural elucidation of the relevant peaks was achieved by negative ionization LC–QTOF–MS. The phenolic compounds galloylquinic acid, quinic acid and gallic acid mainly seemed to be responsible for scavenging the DPPH radical, while glucogallin, trigalloylglucose, gallic acid and tetragalloylquinic acid were considered specifically important for the prediction of TAC determined by the PFC method.

Design of Gigahertz Tuning Range 5 GHz LC Digitally Controlled Oscillator in 0.18 μm CMOS

Abstract In this paper design and simulation of a 4.3 - 5.4 GHz LC digitally controlled oscillator (LC DCO) in IBM 7RF 0.18 μm CMOS technology are presented. Wide gigahertz tuning range is achieved by using two LC DCOs, sharing same structure. DCO is made of one NMOS negative impedance transistor pair and LC tank, which consists of high quality inductor and two switched capacitor arrays for coarse and fine frequency tuning. Coarse and fine tuning switched capacitor arrays are controlled using 6-bit and 3-bit binary words. To increase available frequency values, frequency divider is used. Structure of frequency divider is based on extended-true-single-phase-clock flip-flops. Divider is made of eight divide-by-2 cells connected in daisy chain, thus division values from 2 to 256 are available. Wide tuning range and high division values allows using such DCO with frequency divider in multi-standart transceivers. Whole device is supplied from a single 1.8 V voltage source. At highest frequency proposed device draws 90 mA current including all buffers. Phase noise is −116.4 dBc/Hz at 1 MHz offset from 5.44 GHz carrier. Designed dual DCO and frequency divider occupies about 0.4mm×0.5mm of chip space and whole chip, including pads, occupies 1.5mm × 1.5mm area of silicon.

Irradiation of ultrasound to 5-methylbenzotriazole in aqueous phase: Degradation kinetics and mechanisms

Ultrasonic irradiation (640kHz) leads to the effective degradation of 5-methyl-benzotriazole (5-MBT) in O2 saturated aqueous solution. Up to 97% of 5-MBT is eliminated within 2h of treatment. Upon extended treatment of 6h, UV absorbance of the n→π∗ and π→π∗ transitions associated with aromatic and conjugated systems are completely removed, indicating complete destruction of the aromatic system in 5-MBT. The decomposition of 5-MBT follows pseudo-first order kinetics and the observed decomposition rate dropped significantly in the presence of tertiary butyl alcohol. Detailed product studies were performed employing a negative mode ESI LC–MS. Twenty eight intermediate products were detected during ultrasonic mediated degradation of 5-MBT. Reaction pathways are proposed based on the structures of products assigned to observed 28 masses from LC–MS and commonly accepted degradation pathways observed by thermal and hydroxyl radical mediated pathways often associated with ultrasonic treatment.

负型液晶在ADS广视角技术中的应用

负型液晶在ADS广视角技术中的应用

Effects of Molecular Configuration and Driving Architecture on Electro-Optical Properties of Cholesteric Liquid Crystal Displays

The effects of molecular configuration and driving architecture on the electro-optical properties of cholesteric liquid crystal (ChLC) displays are demonstrated. Two kinds of ChLC cells, composed by mixing the chiral dopant with the positive nematic LC (P-ChLC cell) and with the negative nematic LC (N-ChLC cell), are fabricated in order to make a detailed investigation. Compared with the conventional P-ChLC cell driven by the uniform vertical electric fields, the N-ChLC cell driven by the in-plane switching electric fields shows a higher output light transmittance and a more stable helical molecular configuration, which is attributed to the fact that the focal conic configuration does not exist in the N-ChLC cell. In addition, via the three-terminal-electrode driving architecture, a faster switching response (5.2 ms) of the N-ChLC cell at a low driving voltage is successfully achieved. This study not only exhibits the difference in the electro-optical properties of the P-ChLC and N-ChLC cells, but also provides a driving method for the N-ChLC cell to enhance its electro-optical performance, which is beneficial to the development of fast dynamic optical devices.

P‐117: The Transmittance Study of the Photo Alignment FFS LC Mode

We have investigated a photo alignment material for fringe field switching (FFS) liquid crystal display and it has good alignment performance. It realizes alignment by irradiating linearly polarized light with wavelength of 254nm. We have investigated the factors that affect the transmittance in photo alignment FFS mode. The transmittance becomes smaller with the alignment angle increasing. The transmittance is also affected by the L/S width of the ITO electrode, it becomes smaller with the L/S increasing. The LC type also affect the transmittance, we can get higher transmittance using negative LC.