High ADC Research Articles

Quantitative brain morphological analysis in CHARGE syndrome.

CHARGE syndrome (CS) is a rare congenital syndrome characterized by coloboma, heart anomaly, choanal atresia, retardation of growth and development, and genital and ear anomalies. While several neuroimaging studies have revealed abnormalities such as hypoplasia of the semicircular canal, olfactory nerve, cerebellum, and brainstem, no quantitative analysis of brain morphology in CS has been reported. We quantitatively investigated brain morphology in CS participants using structural magnetic resonance imaging (MRI) (N = 10, mean age 14.7 years old) and high-angular resolution diffusion MRI (HARDI) tractography (N = 8, mean age 19.4 years old) comparing with gender- and age-matched controls. Voxel-based analyses revealed decreased volume of the bilateral globus pallidus (left and right; p = 0.021 and 0.029), bilateral putamen (p = 0.016 and 0.011), left subthalamic nucleus (p = 0.012), bilateral cerebellum (p = 1.5 × 10−6 and 1.2 × 10−6), and brainstem (p = 0.031), and the enlargement of the lateral ventricles (p = 0.011 and 0.0031) bilaterally in CS. Surface-based analysis revealed asymmetrically increased cortical thickness in the right hemisphere (p = 0.013). The group-wise differences observed in global cortical volume, gyrification index, and left cortical thickness were not statistically significant. HARDI tractography revealed reduced volume, elongation, and higher ADC values in multiple fiber tracts in patients in CS compared to the controls, but FA values were not statistically significantly different between the two groups. Facial features are known to be asymmetric in CS, which has been recognized as an important symptom in CS. Our results revealed that the cortex in CS has an asymmetric appearance similar to the facial features. In addition, the signal pattern of high ADC with statistically unchanged FA values of tractography pathways indicated the presence of other pathogenesis than vasogenic edema or myelination dysfunction in developmental delay in CS.

Gas Sensor Array System Properties for Detecting Bacterial Biofilms.

Background:Gas sensor array system is a device that mimics the work of how the nose smells using the gas sensors that could give response toward specific odors. It is used for characterizing the different blended gas that is suited with the biological working nose principle. Thus, it could be used to detect the dental and oral diseases. Periodontitis is one of the diseases caused by the damage on the teeth due to the chronic infection on the gingival structure marked with bacterial plaque and calculus. This study aims to develop an electric nose for odor detection application on the periodontal bacterial biofilm as early detection device for dental and oral disease.Methods:This device is designed as a portable device to ease the data acquisition. The measured data were stored at a database system connected to a real-time computer. A gas array sensor system with six gas sensors (TGS 826, TGS 2602, TGS 2600, TGS 2611, TGS 2612, and TGS 2620) has been assembled for the early detection application for dental and oral disease excreted by the bacterial biofilm that caused dental and oral disease, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Streptococcus mutans, and Enterococcus faecalis.Results:TGS 826 and TGS 2602 sensor had the best response showed by the high ADC delta value.Conclusion:GS 826 and TGS 2602 sensor could be used as a candidate for early detection device for dental and oral disease.

Whole-body low-dose CT recognizes two distinct patterns of lytic lesions in multiple myeloma patients with different disease metabolism at PET/MRI

We evaluated differences in density and 18F-FDG PET/MRI features of lytic bone lesions (LBLs) identified by whole-body low-dose CT (WB-LDCT) in patients affected by newly diagnosed multiple myeloma (MM). In 18 MM patients, 135 unequivocal LBLs identified by WB-LDCT were characterized for inner density (negative or positive Hounsfield unit (HU)), where negative density (HU < 0) characterizes normal yellow marrow whereas positive HU correlates with tissue-like infiltrative pattern. The same LBLs were analyzed by 18F-FDG PET/DWI-MRI, registering DWI signal with ADC and SUV max values. According to HU, 35 lesions had a negative density (− 56.94 ± 31.87 HU) while 100 lesions presented positive density (44.87 ± 23.89 HU). In seven patients, only positive HU LBLs were demonstrated whereas in eight patients, both positive and negative HU LBLs were detected. Intriguingly, in three patients (16%), only negative HU LBLs were shown. At 18F-FDG PET/DWI-MRI analysis, negative HU LBLs presented low ADC values (360.69 ± 154.38 × 10−6 mm2/s) and low SUV max values (1.69 ± 0.56), consistent with fatty marrow, whereas positive HU LBLs showed an infiltrative pattern, characterized by higher ADC (mean 868.46 ± 207.67 × 10−6 mm2/s) and SUV max (mean 5.04 ± 1.94) values. Surprisingly, histology of negative HU LBLs documented infiltration by neoplastic plasma cells scattered among adipocytes. In conclusion, two different patterns of LBLs were detected by WB-LDCT in MM patients. Both types of lesions were indicative for active disease, although only positive HU LBL were captured by 18F-FDG PET/DWI-MRI imaging, indicating that WB-LDCT adds specific information.

Training Sequence-Based Chromatic Dispersion Estimation With Ultra-Low Sampling Rate for Optical Fiber Communication Systems

We present a novel method to estimate chromatic dispersion with ultra-low sampling rate based on training sequence. The under-sampling can be equivalent to over-sampling by splicing points with periodic sequence. The functional relationship between equivalent over-sampling rate and symbol rate, actual sampling rate and sequence period is deduced. To demonstrate the feasibility of the method, the simulation of a 28 GBaud QPSK optical fiber communication system is carried, in which 76 MSa/s sampling rate is equivalent to 66.5 GSa/s sampling rate. The results show that maximum estimation error is less than 160 ps/nm after 100 km to 2300 km SSMF transmission. We also demonstrate the robustness of the proposed method to amplified spontaneous emission and nonlinear noise in a three-channel optical fiber communication system. Moreover, the proposed method has been experimentally verified with a 20.5 GBaud QPSK system, 1.25 GSa/s sampling rate is equivalent to 51.25 GSa/s sampling rate, and estimation error is less than 100 ps/nm and 150 ps/nm after 100 km and 200 km SSMF transmission, respectively. The proposed method eliminates the requirement of high speed ADC and is cost effective, which can be used for optical performance monitoring.

Correlation of Magnetic Resonance Imaging Apparent Diffusion Coeffecient Values with Treatment Outcome in High Grade Glioma Patients Undergoing Concurrent Chemoradiation

High grade gliomas are aggressive malignancies characterized by high proliferation rate, extreme heterogeneity with potential to develop resistance to radiation and chemotherapy as well as short survival period. MRI is considered to be the best imaging modality for brain tumors. ADC values has the potential to serve as an imaging biomarker for response assessment, since it can provide dynamic objective information about tissue and tumor cell density. Low ADC values of diffusion weighted MRI in brain is a negative prognostic variable for patients undergoing radiotherapy. MRI ADC values could provide a reasonably good opportunity to predict the response earlier than conventional methods and thereby could help in individualizing therapy. A total of 22 consecutive postoperative high-grade glioma patients (20 glioblastoma and 2 anaplastic astrocytoma) were analyzed. The ADC values of the tumor on pre-radiotherapy and post radiotherapy MRI were determined from several regions of interest defined in the tumor by “segmentation technique”. This technique expected to give more information, since it measures differing values within the tumor, which would be otherwise averaged out. Radiotherapy along with concurrent chemotherapy was undertaken in all cases. All the patients had at least one post radiotherapy MRI done. Kaplan -Meir survival curves, log rank test were used to evaluate the prognostic factors. The 18 months survival rates associated with low (<0.7x10-3mm2/sec) and high (>1.0x10-3mm2/sec) minimum pre-RT ADCs were 5 and 18 months respectively (p=0.004).The median follow-up period is 13 months. The patients with post RT minimum ADC value below 0.9 x10-3mm2/sec had median survival of 6 months and patients with post RT minimum ADC value above 0.9x10-3mm2 /sec had median survival of 15 months (P value = 0.040). The patients with post RT overall ADC value below 1.3 x10-3mm2/sec had median survival of 6 months and patients with post RT overall ADC value above 1.3x10-3mm2 /sec had median survival of 15 months (P value of 0.04). In high grade glioma patients who have tumors with low ADC values are expected to have have poorer prognosis. In our study of segmentation technique, the minimum ADC values showed better correlation with survival than overall ADC. The minimum ADC at pre-treatment MR imaging is a useful clinical prognostic biomarker. The minimum and overall ADC values from post treatment MR imaging are useful for patient risk stratification after completion of chemo radiation.In future, advanced imaging with new algorithms for 3D ADC mapping diffusion MRI might help in identification of the resistant sub-volumes within the tumor dynamicallly which can lead to biological targeted therapy.

Wide band digital predistortion using iterative feedback decomposition

This paper presents a new digital predistortion (DPD) technique for wide band applications. Digital predistortion is the most useful linearization technique to reduce power amplifier (PA) nonlinearity effects due to its high flexibility and low complexity. However, this technique requires high performances ADC to digitize the feedback signal whose bandwidth is equal to several times the original bandwidth due to spectral regrowth generated by the PA nonlinearity. This point represents one of the main bottlenecks for the deployment of the wideband LTE-A standard. The method proposed in this paper calculates the DPD coefficients iteratively using an ADC with a fixed bandwidth equal to the original bandwidth. The proposed method has been simulated and compared with other methods using Matlab. Simulation results show that the proposed method has almost the same performance as the other methods with an ACPR of − 60 dB. Moreover, it reduces considerably the constraints on the ADC and the power calculation resources.

The protective role of glutamine on enteropathy induced by high dose of soybean meal in turbot, Scophthalmus maximus L.

The aim of this study is to investigate the protective effect and regulatory mechanism of Gln on the enteropathy of turbot induced by soybean meal. Three isonitrogenous and isolipidic practical diets were formulated with fish meal basis (FM), soy protein replacing 40% fish meal protein (SBM) and dietary 2% Ala-Gln in SBM (Ala-Gln) for sextuple replicates of 30 fish each tank for 12 weeks. The fish in SBM group presented distinct enteropathy including declined absorptive surface and overt infiltration of mixed leukocytes in the lamina propria. However, the turbot fed Ala-Gln diet showed the integrity of the intestinal tissue structure and higher ADC and AKP levels like fish in FM group. Compared to SBM group, the inclusion of 2% Ala-Gln in SBM-basal diet significantly elevated the expression of barrier-forming tight junction proteins claudin-4, occludin and ZO-1 and depressed the expression of pro-inflammatory cytokines TNF-α in the intestine. Fish fed Ala-Gln diet showed remarkable increased MUC-2 and PPAR-γ gene expression as well as reduced expression of NF-κB and MLCK equivalent to the level of FM group. Additionally, Gln significantly elevated the relative abundance of Proteobacteria (Vibrio spp.) and declined Bacteroidetes (Bacteroides spp.) relative abundance. The similarity of intestinal microbial communities in Ala-Gln group was notably closer to FM group from PCoA, UPGMA and Heatmap analyses based on weighted UniFrac distance. In conclusion, dietary Gln could probably enhance intestinal barrier function to alleviate enteropathy by improving MUC-2 and PPAR-γ expression and inhibiting NF-κB-MLCK signaling pathway, as well as altering microbiota.

Clinically Relevant Imaging Features for MGMT Promoter Methylation in Multiple Glioblastoma Studies: A Systematic Review and Meta-Analysis.

O6-methylguanine methyltransferase (MGMT) promoter methylation status has been reported as a prognostic biomarker in clinical trials. Our aim was to systematically evaluate imaging features of MGMT promoter methylated glioblastoma and to determine the diagnostic performance of MR imaging for prediction of MGMT promoter methylation in patients with newly diagnosed glioblastoma. A computerized search of Ovid MEDLINE and EMBASE up to February 27, 2018, was conducted. We selected studies evaluating imaging features of MGMT promoter methylated glioblastoma and the diagnostic performance of MR imaging for prediction of MGMT promoter methylation. Pooled estimates of sensitivity and specificity were calculated using a hierarchic logistic regression model. Meta-regression and sensitivity analysis were performed. Twenty-two articles including 2199 patients were included. MGMT promoter methylated glioblastoma is likely to show less edema, high ADC, and low perfusion. Ten articles including 753 patients were included in the meta-analysis. The summary sensitivity was 79% (95% CI, 72%-85%), and the summary specificity was 78% (95% CI, 71%-84%). In the meta-regression, MGMT promoter methylation and mean age were associated with heterogeneity. Sensitivity analysis excluding 1 study resolved the heterogeneity. Included studies used a variety of different MR imaging techniques to predict MGMT promoter methylation. MGMT promotor methylated glioblastoma is likely to show less aggressive imaging features than MGMT promotor unmethylated glioblastoma. Despite the variety of different MR imaging techniques used, MR imaging in patients with newly diagnosed glioblastoma was shown to have the potential to predict MGMT promoter methylation noninvasively.

A GaN/InGaN/AlGaN MQW RTD for versatile MVL applications with improved logic stability * * Project supported by the National Natural Science Foundation of China (Nos. 61302009, 61571171).

To improve the logic stability of conventional multi-valued logic (MVL) circuits designed with a GaN-based resonate tunneling diode (RTD), we proposed a GaN/InGaN/AlGaN multi-quantum well (MQW) RTD. The proposed RTD was simulated through solving the coupled Schrodinger and Poisson equations in the numerical non-equilibrium Green’s function (NEGF) method on the TCAD platform. The proposed RTD was grown layer by layer in epitaxial technologies. Simulated results indicate that its current-voltage characteristic appears to have a wider total negative differential resistance region than those of conventional ones and an obvious hysteresis loop at room temperature. To increase the Al composite of AlGaN barrier layers properly results in increasing of both the total negative differential resistance region width and the hysteresis loop width, which is helpful to improve the logic stability of MVL circuits. Moreover, the complement resonate tunneling transistor pair consisted of the proposed RTDs or the proposed RTD and enhanced mode HEMT controlled RTD is capable of generating versatile MVL modes at different supply voltages less than 3.3 V, which is very attractive for implementing more complex MVL function digital integrated circuits and systems with less devices, super high speed linear or nonlinear ADC and voltage sensors with a built-in super high speed ADC function.

Clustering approach to identify intratumour heterogeneity combining FDG PET and diffusion-weighted MRI in lung adenocarcinoma.

Malignant tumours consist of biologically heterogeneous components; identifying and stratifying those various subregions is an important research topic. We aimed to show the effectiveness of an intratumour partitioning method using clustering to identify highly aggressive tumour subregions, determining prognosis based on pre-treatment PET and DWI in stage IV lung adenocarcinoma. Eighteen patients who underwent both baseline PET and DWI were recruited. Pre-treatment imaging of SUV and ADC values were used to form intensity vectors within manually specified ROIs. We applied k-means clustering to intensity vectors to yield distinct subregions, then chose the subregion that best matched the criteria for high SUV and low ADC to identify tumour subregions with high aggressiveness. We stratified patients into high- and low-risk groups based on subregion volume with high aggressiveness and conducted survival analyses. This approach is referred to as the partitioning approach. For comparison, we computed tumour subregions with high aggressiveness without clustering and repeated the described procedure; this is referred to as the voxel-wise approach. The partitioning approach led to high-risk (median SUVmax = 14.25 and median ADC = 1.26x10-3 mm2/s) and low-risk (median SUVmax = 14.64 and median ADC = 1.09x10-3 mm2/s) subgroups. Our partitioning approach identified significant differences in survival between high- and low-risk subgroups (hazard ratio, 4.062, 95% confidence interval, 1.21 - 13.58, p-value: 0.035). The voxel-wise approach did not identify significant differences in survival between high- and low-risk subgroups (p-value: 0.325). Our partitioning approach identified intratumour subregions that were predictors of survival. • Multimodal imaging of PET and DWI is useful for assessing intratumour heterogeneity. • Data-driven clustering identified subregions which might be highly aggressive for lung adenocarcinoma. • The data-driven partitioning results might be predictors of survival.

Experimental implementation of a 14 bit 80 kSPS non-binary cyclic ADC

This paper presents a prototype of 14 bit 80 kSPS non-binary cyclic ADC without high accuracy analog components and complicated digital calibration. Since the redundancy of non-binary ADC tolerates the non-idealities of analog components such as capacitor mismatch and finite amplifier DC gain, the design consideration of this high accuracy ADC can be only focused on the capacitance of sampling capacitor to satisfy the overall kT/C noise target, the drivability and linearity of amplifier without any high accuracy analog components. The proposed proof-of-concept cyclic ADC has been designed and fabricated in TSMC 90 nm CMOS technology. Measured SNDR = 81.9 dB is achieved at Fs = 80 kSPS with a simple radix-value estimation technique. No other complicated digital calibration is used to compensate the non-linearity of ADC caused by MOM capacitors and a poor gain of the amplifier as low as 66 dB. Measured DNL is − 0.6/+ 0.67 LSB and INL is − 1.2/+ 1.6 LSB. Prototype ADC dissipates 8mW at supply voltage is 3.3 V in analog circuits.

CFCS calibration circuit design for multi-bit pipelined ADC architectures

Design of high resolution ADCs in scaled CMOS technology is challenging due to increased component mismatch, comparator offset, and finite op-amp gain error. In this work, a commutated feedback capacitor switching calibration technique has been proposed to improve the ENOB and linearity of ADCs with multi-bit pipeline architecture. During normal operation of ADC, the fixed sampling capacitor is swapped in the feedback capacitor. We have distributed the sampling capacitor and swap the feedback capacitor with the sampling capacitor(s) in the MDAC of each pipeline stage ADC. The mismatches of different pipeline stages are concurrently corrected in the digital domain. Proposed technique requires digital calibration circuits and requires no extra calibration phase cycles. The prime objective of this work is to achieve high linearity and ENOB in pipeline architectures with low power consumption. Behavioral simulation of 16-bit 5Ms/s pipeline ADC in UMC 0.18 µm double poly triple metal processes with proposed calibration shows significant improvement in DNL with σ = 0.25% capacitor mismatch with correct 16-bit digital output. The design is implemented using HSPICE simulation. The robustness of the proposed technique has been verified by process, temperature and voltage variation simulations and Monte Carlo analysis.

The Value of MRI Brain DWI (ADC) in the Management of Ventriculomegaly in Pediatric Age Group

AbstractBackground: Neurosurgeons need to answer the question: Which infant with an enlarged ventricular system needs neurosurgical intervention (progressive pressure hydroceph-alus) and which one needs to be left alone and diagnosis of compensated pressure hydrocephalus is established using MRI brain DWI (ADC) as well as a useful follow-up tool for the treatment success.Aim of the Work: Investigate the role of ADC's value in children with hydrocephalus to differentiate between compen-sated and progressive hydrocephalus and follow-up after neurosurgical interventions.Patients and Methods: This prospective study included (40 participants) 10 controls (5 males and 5 females) and 30 patients (18 males and 12 females). All the patients underwent routine MRI brain and DWI (ADC) examinations.Results: In our study, we found that DWI (ADC) is a useful non invasive tool in diagnosis and follow-up the treatment success in hydrocephalic children, providing us the mean ADC cut off value (1.0817) for differentiation (compen-sated from progressive pressure).Conclusion: Elevated ADC values in children with pro-gressive hydrocephalus and normalization of the previously high mean ADC value associated with successful neurosurgical intervention, however some patients can present with borderline ADC values and diagnosis of PPH based on the clinical background of the patient and follow-ups. The patients with compensated pressure hydrocephalus, there is no significant decrease of the calculated mean ADC value with follow-ups.

Abstract LB-A20: Strategies to Improve the Safety and Efficacy of Biparatopic Antibody Drug Conjugates

Abstract Antibody drug conjugates (ADC’s) define an emerging class of targeted therapies for cancer, with over 60 ADC’s currently in clinical development. Although antibodies can exhibit exquisite target specificity, expression of the tumor target in normal tissue can limit the tolerated dose that one can achieve with an ADC. We designed two different affinity variant biparatopic antibodies that recognize distinct epitopes on EGFR and promote receptor clustering that leads to enhanced lysosomal trafficking. These ADC’s comprise two different strategies to target EGFR expressing tumors: a high affinity, potency driven approach and a lowered affinity, threshold driven approach. We show that both ADC’s bind to tumor cells, are rapidly internalized, and traffic to the lysosome, where the warhead is efficiently released by lysosomal hydrolases. In vitro, the high affinity ADC exhibited potent killing of cancer cell lines, with IC50’s in the double digit picomolar range in cells with relative EGFR densities as low as 25,000, while the low affinity ADC was most effective when the EGFR density was greater than 500,000. The high affinity ADC was active in patient derived xenograft (PDX) models derived from colorectal and lung cancer patients harboring clinically relevant oncogenic drivers, such as KRAS and BRAF mutations or EGFR aberrations. This ADC induced tumor stasis or regression, with minimally efficacious doses between 1 and 3 mg/kg, in multiple tumor models across a broad range of EGFR expression (IHC scores ranging from 1 to 3). In a cynomolgus monkey safety study, this ADC showed a manageable safety profile at 2 mg/kg, with skin effects as the dose limiting toxicity. The potency of the high affinity ADC may provide meaningful activity across a range of EGFR expression levels, at doses that are tolerable in the clinic. The lowered affinity ADC exhibited an improved safety profile compared to the high affinity ADC, with a highest non-severely toxic dose (HNSTD) of 6 mg/kg, presumably driven by a reduction in binding to normal tissues that express comparably lower EGFR levels relative to the tumor. This lowered affinity ADC showed a more restricted anti-tumor activity, causing regressions at a minimally efficacious dose between 3 and 5 mg/kg, in PDX models that expressed high levels of EGFR, as judged by IHC scores of 3. The lowered affinity ADC required higher EGFR expression for activity, but the improved tolerability may provide a selectivity threshold that discriminates tumor from normal tissue in patients whose tumors overexpress EGFR. Our findings support the concept that modulating antibody affinity can yield distinct ADC’s that represent different strategies for balancing safety and efficacy. The work presented here provides a conceptual framework for designing unique ADC candidates tailored to the particular expression profile and safety considerations around specific tumor associated targets. Citation Format: Frank I. Comer, Xinzhong Wang, Andy Q. Yuan, Vanessa Muniz-Medina, Agnieszka Sadowska, Lan Xu, Samuel Perry, Pamela Thompson, Ralph Minter, Robert Woods, Mary Jane Hinrichs, Molly Reed, Shameen Affif-Rider, Marlon Rebelatto, Charles Brown, Hui Feng, Rakesh Dixit, Steven Coats, Jane Osbourn. Strategies to Improve the Safety and Efficacy of Biparatopic Antibody Drug Conjugates [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-A20.

Analyses of parasitic capacitance effects and flicker noise of the DAC capacitor array for high resolution SAR ADCs

This paper analyses the effects of parasitic capacitances of unit capacitors on the accuracy and the noise performance of the DAC capacitor array in a SAR ADC, showing that thermal noise of the array decreases while gain error is introduced. The gain error is almost independent of the number of bits, but the dynamic range of the high resolution ADC is severely reduced due to the gain error. The post-layout parasitic capacitance analysis of a 10-bit poly-poly array shows a large difference between the top-plate and bottom-plate parasitic capacitances so that the gain error can be decreased by 152 times when top-plates are connected together as the output node of the array. The switching transistors' flicker noise calculation for a 10-bit and an 18-bit SAR ADC shows that flicker noise can be safely ignored for 10-bit 1MSPS SAR, but should be considered for the higher resolution SAR ADCs.

The Effects of Comparator Dynamic Capacitor Mismatch in SAR ADC and Correction

This paper proposes a method of correcting the nonlinear parasitic capacitor of the input pair of comparator in successive approximations analog-to-digital converters (SAR ADCs). The correction method is proposed for the conventional binary-weighted capacitor array topology used in most of high resolution and high speed SAR ADCs. The effects of dynamic capacitor mismatch are first analyzed and then two feasible correction schemes are proposed to mitigate the impact of the nonlinear parasitic capacitor of the comparator. To verify the effectiveness of the proposed method, we designed a SAR ADC in a CMOS 40 nm process and characterized the design by intensive post-simulations. With the proposed correction schemes, the SFDR and SNDR of the SAR ADC increase about 7 and 4 dB, respectively, the differential nonlinearity and integral nonlinearity after calibration are improved from 1.00 and 3.81 to 0.67 LSB/0.57 LSB and 1.46 LSB/0.77 LSB, respectively.

Analyses of parasitic capacitance effects and flicker noise of the DAC capacitor array for high resolution SAR ADCs

This paper analyses the effects of parasitic capacitances of unit capacitors on the accuracy and the noise performance of the DAC capacitor array in a SAR ADC, showing that thermal noise of the array decreases while gain error is introduced. The gain error is almost independent of the number of bits, but the dynamic range of the high resolution ADC is severely reduced due to the gain error. The post-layout parasitic capacitance analysis of a 10-bit poly-poly array shows a large difference between the top-plate and bottom-plate parasitic capacitances so that the gain error can be decreased by 152 times when top-plates are connected together as the output node of the array. The switching transistors' flicker noise calculation for a 10-bit and an 18-bit SAR ADC shows that flicker noise can be safely ignored for 10-bit 1MSPS SAR, but should be considered for the higher resolution SAR ADCs.

1-2 Topics (2); High speed imaging, ADC and readout circuits

1-2 Topics (2); High speed imaging, ADC and readout circuits

Discovery of novel high potent and cellular active ADC type PTP1B inhibitors with selectivity over TC-PTP via modification interacting with C site

PTP1B serving as a key negative regulator of insulin signaling is a novel target for type 2 diabetes and obesity. Modification at ring B of N-{4-[(3-Phenyl-ureido)-methyl]-phenyl}-methane-sulfonamide template to interact with residues Arg47 and Lys41 in the C site of PTP1B by molecular docking aided design resulted in the discovery of a series of novel high potent and selective inhibitors of PTP1B. The structure activity relationship interacting with the C site of PTP1B was well illustrated. Compounds 8 and 18 were shown to be the high potent and most promising PTP1B inhibitors with cellular activity and great selectivity over the highly homologous TCPTP and other PTPs.

Fibrosis quantification in Hypertensive Heart Disease with LVH and Non-LVH: Findings from T1 mapping and Contrast-free Cardiac Diffusion-weighted imaging

This study assessed the extent of fibrosis and the relationship between the ADC value and systolic strain in hypertensive patients with left ventricular hypertrophy (HTN LVH) and hypertensive patients without LVH (HTN non-LVH) using cardiac diffusion-weighted imaging and T1 mapping. T1 mapping was performed in 13 HTN LVH (mean age, 56.23 ± 3.30 years), 17 HTN non-LVH (mean age, 56.41 ± 2.78 years), and 12 normal control subjects (mean age, 55.67 ± 3.08 years) with 3.0 T MRI using cardiac diffusion-weighted imaging and T1 mapping. HTN LVH subjects had higher native T1 (1233.12 ± 79.01) compared with controls (1133.88 ± 27.40) (p < 0.05). HTN LVH subjects had higher ECV (0.28 ± 0.03) compared with HTN non-LVH subjects (0.26 ± 0.02) or controls (0.24 ± 0.03) (p < 0.05). HTN LVH subjects had higher ADC (2.23 ± 0.34) compared with HTN non-LVH subjects (1.88 ± 0.27) or controls (1.61 ± 0.38), (p < 0.05). Positive associations were noted between LVMI and ADC (Spearman = 0.450, p < 0.05) and between LVMI and ECV (Spearman = 0.181, p < 0.05). ADC was also related to an increase in ECV (R2 = 0.210). Increased levels of ADC were associated with reduced peak systolic and early diastolic circumferential strain rates across all subjects. Contrast-free DW-CMR is an alternative sequence to ECV for the evaluation of fibrosis extent in HTN LVH and HTN non-LVH, while native T1 has limited value.