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Background: Our goal was to investigate linkages between skin color parameters and skin hydration. Since most prior studies focused on stratum corneum hydration, we focused on epidermal and dermal hydration in relation to skin color parameters in both sexes. Materials and Methods: Thirty adults (16 female) with an age ± SD of 24.3 ± 0.6 years participated. Three sites on both volar forearms were evaluated for melanin index (MI), erythema index (EI), Individual Typology Angle (ITA), tissue dielectric constant (TDC) values to depths of 0.5 mm (TDC0.5) and 2.5 mm (TDC2.5), and Fitzpatrick skin type (FST). Results: MI and EI were highly correlated (r = 0.800, p < 0.001) with maximum differences in MI and ITA along the arm of 3% and 6.3% with no difference between arms. Male MI was greater than females (p < 0.01). Male TDC2.5 was 36.1 ± 5.4 and correlated with EI (r = 0.231, p = 0.035). Contrastingly, female TDC25 was 28.5 ± 3.6 with no correlation with EI but was correlated with MI (r = −0.301, p = 0.003). These differential patterns held true for TDC0.5. For both sexes, FST and ITA were highly correlated (r = −0.756, p < 0.001). Conclusions: The findings revealed several correlations between skin color parameters and hydration that differed between males in females in some cases. The observed correlations may indicate that melanin may differentially impact water‐holding capacity between sexes and provides a future research target. Further, these initial findings also may hold significance for dermatological assessments and the customization of skincare treatments tailored to individual skin types and demographics. [ABSTRACT FROM AUTHOR]

TDC are hematopoietic cells that combine dendritic cell (DC) and conventional T‐cell markers and functional properties. They were identified in secondary lymphoid organs (SLOs) of naïve mice as cells expressing CD11c, major histocompatibility molecules (MHC)‐II, and the T‐cell receptor (TCR). Despite thorough characterization, a physiological role for TDC remains to be determined. Unfortunately, using CD11c as a marker for TDC has the caveat of its upregulation on different cells, including T cells, upon activation. Here, we took advantage of Zbtb46‐GFP reporter mice to explore the frequency and localization of TDC in different tissues at steady state and upon viral infection. RNA sequencing analysis confirmed that TDC sorted from Zbtb46‐GFP mice have a gene signature that is distinct from conventional T cells and DC. In addition, this reporter model allowed for identification of TDC in situ not only in SLOs but also in the liver and lung of naïve mice. Interestingly, we found that TDC numbers in the SLOs increased upon viral infection, suggesting that TDC might play a role during viral infections. In conclusion, we propose a visualization strategy that might shed light on the physiological role of TDC in several pathological contexts, including infection and cancer. [ABSTRACT FROM AUTHOR]

Global warming has multifarious adverse effects on plant growth and productivity. Nonetheless, the effects of endogenous phytomelatonin on the high‐temperature resistance of plants and the underlying genetic mechanisms remain unclear. Here, herbaceous peony (Paeonia lactiflora Pall.) tryptophan decarboxylase (TDC) gene involved in phytomelatonin biosynthesis was shown to respond to high‐temperature stress at the transcriptional level, and its transcript level was positively correlated with phytomelatonin production. Moreover, overexpression of PlTDC enhanced phytomelatonin production and high‐temperature stress tolerance in transgenic tobacco, while silencing PlTDC expression decreased these parameters in P. lactiflora. In addition, a 2402 bp promoter fragment of PlTDC was isolated, and DNA pull‐down assay revealed that one APETALA2/ethylene‐responsive element‐binding factor (AP2/ERF) transcription factor, PlTOE3, could specifically activate the PlTDC promoter, which was further verified by yeast one‐hybrid assay and luciferase reporter assay. PlTOE3 was a nucleus‐localized protein, and its transcript level responded to high‐temperature stress. Additionally, transgenic tobacco overexpressing PlTOE3 showed enhanced phytomelatonin production and high‐temperature stress tolerance, while silencing PlTDC expression obtained the opposite results. These results illustrated that PlTOE3 bound the PlTDC promoter to enhance high‐temperature stress tolerance by increasing phytomelatonin production in P. lactiflora. This study is to elucidate the effects of endogenous phytomelatonin on the high‐temperature resistance of plants, and the results illustrated that PlTOE3 bound the PlTDC promoter to enhance high‐temperature stress tolerance by increasing phytomelatonin production in herbaceous peony. [ABSTRACT FROM AUTHOR]

This study investigated impacts of local skin heating on skin properties and tested whether skin changes depended on heat‐induced hyperaemia. It was reasoned that heat‐induced vasodilation impacts accompanying interstitial fluid changes. Forearm skin was locally heated from a baseline of 35°C to 40–42°C in 30 young adults (15 females, 15 males, 24.9 ± 2.1 years) and non‐heated in 10 others (5 females, 5 males, 25.2 ± 1.3 years. Skin blood flow (SBF) was continuously measured using a laser Doppler method and skin tissue dielectric constant (TDC), stratum corneum capacitance (SCC) and transepidermal water loss (TEWL) were measured before and after maintained heat for 12 min. TDC values were determined to effective measurement depths of 1.5 mm (TDC15) and 2.5 mm (TDC25). Results showed a large heat‐induced hyperaemia, with SBF increasing on average 8.8‐fold from its baseline of 35°C. Heating also caused significant increases in TDC, SCC and TEWL that, compared to preheating, increased approximately 1.1‐fold, 3.1‐fold and 4.5‐fold. None of these skin changes correlated with the magnitude of the SBF hyperaemic response. Absence of this correlation may indicate that in young healthy adults, increased capillary filtration due to heat‐induced arteriolar vasodilation is rapidly accommodated by postcapillary reabsorption, enhanced lymphatic activity and TEWL processes. An alternate explanation is that heating caused increased red cell oscillations that were detected as part of the laser Doppler increase without representing increased capillary flux. The major determinant of the Increases in TDC, SCC and TEWL is likely a consequence of heat‐induced eccrine gland activation. Studies of older persons or those with depressed function are warranted. [ABSTRACT FROM AUTHOR]

A high‐precision measurement method, based on multiple sampling, is proposed for the time interval of two signals in this study. A time interval measurement circuit integrated into the time‐to‐digital converter (TDC), is designed based on this high‐precision measurement method. In the TDC, the authors use two identical delay lines as the holding module to ensure the two signals with a constant time interval. The TDC samples the two signals multiple times by a clock signal, whose period is shorter than that of the delay line. Consequently, the problem of limited resolution caused by a mismatch between delay lines in the delay‐line structure can be avoided, and the precision of the output can be improved. The proposed TDC is designed and simulated in Semiconductor Manufacturing International Corporation (SMIC) 0.18 μm complementary metal–oxide–semiconductor process. Simulation results show that the differential non‐linearity and the integral non‐linearity are always less than one least significant bits. The proposed TDC achieves input dynamic range of 0–32.13 ns and time resolution of 9 ps. [ABSTRACT FROM AUTHOR]

Time‐to‐digital converter (TDC) is one of the important blocks in most of the digital systems that need to have high resolution. Time difference amplifier (TDA) is used in TDC for increasing the resolution. In this study, an all‐digital TDA is proposed. The proposed TDA uses the delay lines with difference delay for amplifying. The proposed circuit is designed and simulated in 65 nm CMOS technology and has a gain of ten and a chip area of about 0.003 mm2. The calculated maximum gain error is 5%. The proposed TDA consumes 0.94 mW power under 1.1 V supply voltage. [ABSTRACT FROM AUTHOR]

A Vernier ring‐oscillator‐based time‐to‐digital converter (TDC) with a new prelogic is presented. Experimental results show that the proposed architecture achieve a 5.5 ps RMS timing jitter with a 5.1 ps LSB within an area of 0.00151mm2. Thanks to the new prelogic circuit, the power consumption of the circuit was optimised to 22μW at a rate of 1 Mevents/s for a dynamic range of 4 ns. The area, timing jitter and power consumption make the TDC suitable for an array of electronic readout in a position emission tomography single photon avalanche diode based detectors. [ABSTRACT FROM AUTHOR]

A multiphase all‐digital crystal‐less clock generator (CLCG) with an interpolating digital controlled oscillator (DCO) that achieves an operating frequency of 500 MHz with 10‐phase outputs is proposed. The CLCG adopts a specific temperature coefficient of a time‐to‐digital convertor (TDC) to create a positive or negative temperature coefficient and compensates for the DCO frequency drift. A time amplifier (TA) can extend the timing resolution of the TDC and reduce the effects of process variations in order to tune the TA gains. The frequency compensator adopts the frequency difference between the ring oscillator and DCO to reduce the frequency drift. The frequency accuracy is 69 ppm/°C from − 20 to 80°C. The root mean square jitter and output phase noise are 3.86 ps and − 100.36 dBc/Hz at 1 MHz, respectively. The core area of the test chip is 350 × 420 μm2 in a 65‐nm CMOS process. At a supply voltage of 0.6 V, the power consumption is 1.8 mW for the 5 Gb/s clocking system. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a low‐power and high‐resolution latch‐based time‐to‐digital converter (TDC) based on a multistage scheme is proposed. The proposed multistage TDC includes coarse, middle, and fine stages. The coarse stage is a new design of the flash TDC that is implemented by latches without using the delay cell. Also, the middle stage is a new design of the Vernier TDC with employed latches. The fine stage comprises parallel latches with different input loads. [ABSTRACT FROM AUTHOR]

This paper presents the design of an all-digital delay-locked loop (ADDLL) with duty-cycle correction using reusable time-to-digital converter (TDC). The proposed ADDLL uses a reusable TDC for achieving a wide-operating frequency range. In addition, it achieves the frequency doubling output clock easily by changing the quantization interval. It is implemented in a 0.18-µm complementary metal-oxide semiconductor technology. This circuit corrects the duty cycle and synchronizes the input and output clocks in 10 clock cycles. The output duty cycle is corrected to 50 ± 1.5% as the input duty cycle ranges from 25% to 75%. The acceptable input frequency range is from 300 to 900 MHz without frequency doubling. The acceptable input frequency range is from 150 to 450 MHz when using frequency doubling. It dissipates 6.2 mW from a 1.8-V supply at 900 MHz. The peak-to-peak and RMS jitters at 900 MHz are 14 and 1.8 ps, respectively. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This study presents the design of wide‐area fractional order damping controller for low frequency inter‐area oscillations in Western Electricity Coordinating Council (WECC) system. The developed wide‐area damping control scheme is implemented in a decentralised manner by examining the entire system through decentralised identification at the level of each generator bus and FACTS devices in large‐scale system. The decentralised identification is done by applying n4sid (Subspace State Space System Identification) algorithm to the time‐domain simulated response of WECC system. The main features of the proposed approach are: (a) measurement‐based control which does not require complete model of WECC; (b) minimise the communicating signals required for damping controller and incorporate practical method of time‐delay compensator (TDC) design to reduce the effect of time‐varying delay. The performance of wide‐area control (WAC) scheme is tested on the practical WECC system and verified by non‐linear time‐domain simulation. The proposed decentralised WAC scheme is compared with local and centralised control scheme, which enhances the damping of inter‐area oscillation effectively compared to local control scheme and more reliable compared to centralised control scheme and its robustness is verified over a wide‐range of operating conditions. [ABSTRACT FROM AUTHOR]

Background Biophysical measures to assess that skin water includes stratum corneum hydration via capacitance ( SC), dermal water via tissue dielectric constant ( TDC), and transepidermal water loss ( TEWL). Since skin differs among anatomical sites and tissue depth we sought to determine the site and depth variability of these measures and their relationships. Methods Measurements were done at 17 skin sites from forehead to foot in 32 supine healthy women. Measurements included SC at 1.25 MHz, TDC at 300 MHz to depths of 0.5, 1.5, and 2.5 mm and TEWL. Results Tissue dielectric constant decreased with increasing depth at forehead, forearm, and calf; increased with depth at palm, thenar eminence and great toe; and was independent of depth at cheek, hand dorsum, thumb pulp, and foot dorsum. SC correlated with TDC at most sites and depths. TEWL correlated with TDC at 2.5 mm only at calf sites and thenar eminence. Conclusions Results establish parameter ranges for each measure, show that TDC values do not necessarily change with skin depth, and show a significant correlation between TDC and SC values at most sites. These correlations suggest that SC hydration but not TEWL is directly linked to dermal tissue water levels in normal skin. [ABSTRACT FROM AUTHOR]

A novel 9‐bit time–digital‐converter (TDC)‐assisted analogue–digital‐converter (ADC) supporting energy‐efficient high‐speed compressive‐sensing (CS) operation is presented. With a voltage–time‐converter serving as the cross‐domain residue conveyer, the proposed two‐stage self‐timed pipeline ADC architecture hybrids a voltage‐domain comparator‐interleaved successive‐approximation (SAR) ADC front‐end and a time‐domain locally readjusted folding two‐dimensional Vernier TDC back‐end. Implemented in 65 nm CMOS technology, the prototype benefits from both the CS‐enabled sub‐Nyquist operation and the hybrid quantisation scheme, leading up to 4 GS/s equivalent speed with 34.2 dB signal‐noise‐distortion‐ratio (SNDR) and a figure‐of‐merit (FOM) of 101 fJ/conversion step. [ABSTRACT FROM AUTHOR]

It is noted that the high-group dispersion leads to huge enhancement of the fiber optic gyroscope's sensitivity in a resonating structure, and an approach to evaluate and design resonator gyroscope with slow-light property is proposed. And then we could adopt time interval measurement to obtain angular velocity. A high-resolution time-to-digital converter implemented in a general purpose field-programmable-gate-array has been introduced. Experiments show that such a novel structure would allow for several orders of magnitude sensitivity enhancement that is particularly important for fiber optic gyroscope. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3220–3223, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23904 [ABSTRACT FROM AUTHOR]

Three‐dimensional (3D) dynamic random‐access memory (DRAM) with TSVs has been proposed due to continuous demands for low‐power and high‐density memory without IO loading limitation. However, the process difference among the stacked dies causes the timing mismatch of internal signals. To remove signal confliction and reduce signal skews among the stacked dies, the simultaneous process self‐calibration scheme is proposed. The stacked dies using the proposed scheme detect the slowest signal among the stacked dies and internal signals are aligned with the slowest signal at the same time. The time for aligned operation is within one read loop and the scheme is turned off after calibration to reduce additional standby current. The 3D double‐data rate 4 (DDR4) DRAM using the proposed scheme is operated over 2133 Mbit/s at 1.2 V. [ABSTRACT FROM AUTHOR]

Melatonin‐deficient rice with a semidwarf erect‐leaf phenotype was created by suppressing serotonin N‐acetyltransferase 2 (SNAT2). We generated an RNAi transgenic rice that suppressed tryptophan decarboxylase (TDC), which encodes the first TDC enzyme committed step for melatonin biosynthesis in plants catalyzing the conversion of tryptophan into tryptamine, to determine whether other transgenic rice with downregulated melatonin biosynthetic genes exhibited the same erect‐leaf phenotype as the snat2 RNAi rice. The TDC RNAi rice produced significantly less melatonin than the wild type and exhibited a semidwarf phenotype, but no erect‐leaf phenotype was observed. In contrast, tryptamine 5‐hydroxylase (T5H) knockout Sekiguchi rice and caffeic acid O‐methyltransferase (COMT) RNAi rice seedlings were semidwarf phenotypes with erect leaves, as was the snat2 RNAi rice due to a melatonin deficiency. All RNAi rice plants showing erect‐leaf phenotypes had lower expression levels of the DWARF4 gene, which is a key enzyme for brassinosteroid (BR) biosynthesis, leading to lower BR levels than their respective wild types. Suppressing melatonin synthesis did not alter the contents of indole 3‐acetic acid (IAA), suggesting the irrelevance of melatonin deficiency to IAA biosynthesis. These data indicate that a semidwarf seedling is a common rice phenotype by the lack of melatonin synthesis with or without BR suppression in a melatonin biosynthetic gene‐specific manner. [ABSTRACT FROM AUTHOR]

Oversampled converters based on voltage controlled ring oscillators are an attractive solution because of their digital implementation and simplicity. However, the voltage‐to‐frequency conversion of ring oscillators displays a poor linearity. Replacing the ring oscillator by a pulse frequency modulator (PFM) that provides improved linearity at the expense of feedback and analogue amplification is proposed. Compared to the equivalent continuous time sigma–delta modulators, the PFM may be more tolerant to circuit impairments. In addition, the output data of the proposed architecture is a multibit sequence through the use of a time‐to‐digital converter TDC instead of a Flash quantiser or a multibit digital‐to‐analogue converter. A high dynamic range can be achieved without severe constraints on analogue mismatch or clock jitter. [ABSTRACT FROM AUTHOR]

A time‐to‐digital converter (TDC) for a low‐power, wide‐range all digital phase‐locked loop (ADPLL) is presented. The proposed TDC uses an enabling signal with variable duration to achieve low power and wide range. For verification purpose, the ADPLL is fabricated in a 0.11 µm CMOS technology. The ADPLL dissipates 6.02mW at an output frequency of 1.68GHz and its output frequency is measured as 0.24–1.68 GHz from a 1.2 V supply. [ABSTRACT FROM AUTHOR]