Subjective written questionnaire also showed elevated symptoms of

Subjective written questionnaire also showed elevated symptoms of driving fatigue. They proposed using HRV as a quantitative index for driving fatigue. Li et al. [13�C14] further studied the effect of acupuncture on driving fatigue. Their findings suggested that driving fatigue induced symptoms Tubacin MM could be attenuated by acupuncture.In this study, we monitored multiple physiological parameters, including palm temperatures (left and right), HR, BP (SYS/DIA), and HRV parameters before and after an indoor driving task lasting for 120 minutes. Volunteers were divided into two groups. One group conducted the driving task continuously while the other group had a 15-min exercise break taken at mid-term (60-min from start) of driving. By comparing the physiological changes between the two groups, the effect of exercise break on driving fatigue could be investigated.

In addition, a written questionnaire was filled by each participant before and after the driving task to gauge the subjective feeling of driving fatigue. It is our expectation that the results of this series of studies (including Liang et al. [15] that was published earlier) could provide useful information for the quantitative definition Inhibitors,Modulators,Libraries of driving fatigue based upon physiological parameter changes. Identification of key parameters for Inhibitors,Modulators,Libraries monitoring driving fatigue is the next goal for these studies. This is a prerequisite step in the development of driving fatigue preventive devices.2.?Materials and MethodsAn indoor simulated driving test (instead of a road driving test) was selected in consideration of cost, safety, and control of variables.

2.1. SubjectsIn order to avoid gender Inhibitors,Modulators,Libraries and age influences on HRV [16�C17], a total of 40 male subjects within a tight age range (22.6 �� 1.6 years old; see Table 1; all college or graduate school students) were recruited to take the driving test. All subjects Inhibitors,Modulators,Libraries were currently healthy and not under
The continuous changes in life quality over the last decades have led to new daily life needs. For instance, the increase in life expectancy and population ageing has resulted in an increase in the number of applications of new technologies to support elderly people. An important illustration of this is the growing field of in-home health care devices. This tendency is expected to Dacomitinib be maintained in the near future since the speed of ageing is likely to increase over the coming decades [1].

On the other hand, cardiovascular and cardiorespiratory diseases are constantly growing among world population. free overnight delivery Many reasons explain this, among them the mental stress caused by the modern life, which is full of deadlines, expectations and disappointments. Actually, cardiovascular diseases represent the first cause of death (29.34% of causes) worldwide while the cardiorespiratory diseases represent 6.49% of the death causes according to the World Health Organization (WHO) [2].

A power source with a constant voltage of 1 V was connected in se

A power source with a constant voltage of 1 V was connected in series to the sensor material and the temperature compensating material, and the voltage difference of the selleck chem sensor material (voltage between electrodes AB) was measured as the output of the sensor element using the temperature compensating material.Figure 1.Electrical circuit for the sensor element using the temperature compensating material.3.?Results and Discussion3.1. Optimization of Y concentrationXRD patterns for the thick films fired at 1,373 K are shown in Figure 2. XRD analysis was carried out for thick films on alumina substrates. In the case of CeY20, the analysis was carried out for thick films with Pt electrodes, while for the samples with other concentrations of Y, thick films specially prepared for XRD analysis were used without Pt electrodes.

Figure 2.XRD patterns for thick films with various Y concentrations, fired at 1,373 K. ��CeYx�� indicates a composition of Ce1-x/100Yx/100O2-��. ��s�� indicates the peak from the substrate.All of the XRD peaks in patterns
In view of the growing concerns about Inhibitors,Modulators,Libraries issues such as food security, healthcare, evidence-based care, infectious disease, and tailor-made medicine, the development of a portable gene-based point-of-care testing (POCT) system has become an important task. Conventional DNA chips are based Inhibitors,Modulators,Libraries on optical detection, whereby the target DNA is labeled with fluorophors and detected by optical laser scanner. This method is, however, problematic in that it requires a technically trained operator and expensive, nonportable equipment.

For a portable gene-based POCT system that anyone can operate anywhere and obtain immediate results, a new biosensor chip must be developed. Inhibitors,Modulators,Libraries Electrical detection using CMOS integrated circuits has great potential since it eliminates the labeling process, achieves high accuracy and real-time detection, and offers the important advantages of low-cost and small-sized equipment. Inhibitors,Modulators,Libraries Several methods have been investigated based on the detection of change in capacitance [1-3], current [4-6], and electric potential [7-10] by molecular interaction. Among them, the detection of electric potential change based on an ion-sensitive field-effect transistor (ISFET) [11] has shown excellent sensitivity for ion concentration [12], penicillin [13], glucose [14], urease [15], neuronal activity [16], extracellular recording [17], specific DNA sequence including single nucleotide polymorphisms (SNPs) [18-21], and so on.

The operating principle of the ISFET is simple. Specific Anacetrapib molecules are selectively taken into a probe layer on the FET channel, which detects the molecular charge in the probe layer. In the case of DNA detection, the probe is single-stranded (ss) DNA with a known sequence, selleck chemicals immobilized on the substrate. When the target ss-DNA is supplied, hybridization occurs if the target DNA is complementary to the probe DNA.

This scheme is based on broadcast transmission and the sender onl

This scheme is based on broadcast transmission and the sender only requires the position of its own and the destination. All active neighborhood nodes who receive the packet will go through the contention phase. Once the contention phase is complete, the winner (the node that is closest to the destination) will relay the packet using the same mechanism. selleck chemical Erlotinib This process will repeat until the destination becomes one-hop away. The authors assumed that all nodes in the neighborhood do not remain active all the time. Due to the dynamics of the sleep modes, different sets of potential relays will be available. However, mostly the potential route is close to the same or shortest route, which makes easier for an adversary to trace back to the sender.A. Capone et al. [10] proposed Simple Forwarding over Trajectory (SiFT) scheme.

This scheme is based on broadcast transmission and does not maintain neighborhood positions Inhibitors,Modulators,Libraries and states. Each node who receives the packet will make the decision of forwarding that packet based only on its own position, the position of a transmitter and the trajectory. The difference between the GeRaF [8, 9] and the SiFT scheme is that, the GeRaF does not use trajectories but the position of the destination. If nodes are static then similar to the GeRaF the potential route is close to the same or shortest route, which makes it easier for an adversary to trace back to the sender.A. D. Wood et al. [6] have proposed a configurable secure routing protocol family called Secure Implicit Geographic Forwarding (SIGF) for WSNs.

The SIGF is based on Inhibitors,Modulators,Libraries the Implicit Geographic Forwarding (IGF) protocol [11], in which a packet is forwarded to the node that lies within the region of 60�� sextant, centered on the direct line from the sender to the destination. The SIGF protocol provides some aspects of networks privacy such as data, route and location privacy, but it does not provide identity privacy. Another limitation of the SIGF protocol is that, when there is no trusted node within a forwarding area (assuming 60�� sextant), it will forward the packet to an un-trusted Inhibitors,Modulators,Libraries node. So, the reliability of the path is affected.Table 1 compares the proposed privacy preserving schemes. It clearly shows that none of the schemes currently provide full network Inhibitors,Modulators,Libraries level privacy.Table 1.Comparison of privacy preserving schemes.3.?Network, Assumptions and Adversary Model3.

1. Network ModelA wireless sensor network (WSN) is composed of large number of small sensor nodes that are of limited resource and densely deployed in an environment. Whenever end users require information about any event related to some object(s), they Batimastat send a query to the sensor network via the base station. And the base station propagates that query to the entire network or to a specific region of the network. In response to that query, sensor nodes send back required sellectchem information to the base station. A typical wireless sensor network scenario is shown in Figure 1.

The matrices A11(t) s��s, A12(t) s��m, A21(t) m��s, A22(t) m�

The matrices A11(t) s��s, A12(t) s��m, A21(t) m��s, A22(t) m��m, C1 s��r, C2 m��r, b1 sy b2 m are the corresponding partitions of A(t), C y b(t), respectively.Equation (3) represents the asymptonic observer that was designed
Over recent years, fault diagnosis for networked control kinase inhibitor Ceritinib system (NCS) using the mode-based analytical redundancy method have received significant attention. In [1,2], the overviews of main ideas and results on fault diagnosis of NCS are given, including the fundamentals of fault diagnosis for NCS with information scheduling, fault diagnosis approaches based on the simplified time-delayed system models and the quasi T-S fuzzy model, and fault diagnosis for linear and nonlinear NCS with long time-delay.

However, most of the available Inhibitors,Modulators,Libraries results make use of Inhibitors,Modulators,Libraries time-triggered state estimation techniques by sampling the output of plant at an essentially equidistant time instant. Because the sampling period is determined according to the worst case operation conditions that rarely occur, the time-triggered sampling leads to a conservative usage of the communication bandwidth.On the other hand, recent advances in computing and communication technologies enable the wireless networks (e.g., Bluetooth, wirelessHART and ZigBee) to rapidly replace wired networks in many applications, including industrial control and monitoring, home automation and consumer electronics, security and military sensing, and health monitoring [3,4]. Though the wireless channels are easier and cheaper to deploy and avoid cumbersome cabling, they also pose serious resource constraints.

Therefore, applying the time-triggered sampling method to the wireless NCS may have some negative effects on the estimation and control performance of system, such as wasting Inhibitors,Modulators,Libraries the scarce communication resource and further shortening the lifetime of overall system. Since the event-triggered sampling strategies present a number of potential advantages for NCS, such as clock-free operation, less traffic requirement, and better resource utilization, they have been regarded as the possible Inhibitors,Modulators,Libraries and important alternatives to the time-triggered sampling.Until now, numerous event-triggered sampling concepts have been proposed in the literature, such as send-on-delta sampling [5,6], level-crossing sampling [7], deadband sampling [8], Lebesgue AV-951 sampling [9], send-on-area sampling [10], error energy sampling [11], self-triggered sampling [12], etc.

Although these schemes have different terminologies, the same attribute is that the signal is sampled only when an a priori defined events occurs in the data monitored by sensors. For instance, the studies in [5�C9] are concerned with the same sampling criterion where the event is defined as that the difference �� between the current sensor value and the last selleck kinase inhibitor transmitted one is greater than a given threshold. While in [10] and [11], the event is that the integral and energy of �� is greater than a given threshold, respectively.

Figure 1 illustrates the FET-based biosensor structure and the me

Figure 1 illustrates the FET-based biosensor structure and the measurement system, showing the connection diagram of the instrumentation amplifier AD620.Figure 1.Schematic illustration of the FET-based else biosensor measurement system showing the connection diagram of the instrumentation amplifier AD620 used as unity gain buffer.3.?Results and Discussion3.1. Glucose ResponseThe enzyme immobilization process is an important step in biosensor fabrication since the enzyme cannot be lixiviate from the support. Inhibitors,Modulators,Libraries GA is an extensively used cross-linking Inhibitors,Modulators,Libraries agent in enzyme immobilization processes in combination with BSA. Figure 2 displays the typical response of the PPI/NiTsPc-GOx FET-based biosensor and the influence of the BSA on the output signal.
Inhibitors,Modulators,Libraries A response time��defined as the time necessary to reach 90% of the steady-state response [12]��of about 7 min can be estimated. This time appears to be slightly lower for the biosensor without BSA due to the faster ionic diffusion, as the presence of BSA may make the H+ diffusion difficult. Inhibitors,Modulators,Libraries On the other hand, the presence of BSA allows greater exposure of the enzyme active sites, since they are not used in the cross-linking process, enhancing the enzyme activity and thus improving the biosensor signal.Figure 2.Response of PPI/NiTsPc-GOx FET-based biosensor with (black line) and without (red line) the presence of BSA in the process of enzyme immobilization to detect 0.5 mM of glucose. Measurement conditions: buffer solution 10 mM, pH 7.5.The dependence of the voltage response versus glucose concentration (analytical curve) is shown in Figure 3.
The linear range is up to 0.4 mM with detection limit of 0.027 mM determined in the linear region of the biosensor calibration curve according to the literature [13].Figure 3.Analytical curve of the PPI/NiTsPc-GOx FET-based biosensor. Measurement conditions: buffer solution 10 mM, pH 7.5The greatest obstacle in the development of FET-based Anacetrapib glucose biosensors is their dynamic range limitation due to the low oxygen concentration of real blood samples. Although at first a sensitivity of up to 1 mM seems to be out of the range of interest, which is about 4�C7 mM for real blood samples, our sensor is able to detect diluted human serum samples as suggested in the literature [14].
Using such a strategy, the sensors proposed here coul
The accurate measurement of NH4+ ion in an aquatic environment is of significant interest in environmental biological studies and the environmental evaluation following website of water since it is known to be toxic for aquatic organisms. In this sense, several methods have been proposed, most of them involving ion chromatography [1�C3], potentiometry [4,5] or flow injection systems [6�C11].Most of the ion chromatography procedures proposed for its determination involve elaborate pre-column derivatization in some kind of matrix. Mori et al.

The significant developments of impedimetric biosensors for bacte

The significant developments of impedimetric biosensors for bacteria detection in the past five years have been reviewed especially according to the classification of Inhibitors,Modulators,Libraries with or without specific bio-recognition element. In addition, some microfluidics systems, which were used in the construction of impedimetric biosensors to Inhibitors,Modulators,Libraries improve analytical performance, have been covered in this review.2.?Principle of Impedance TechniqueElectrical impedance (Z) is defined as the ratio V(t)/I(t) of an incremental change in voltage to the resulting change in current. From this definition, the impedance Z is the quotient of the voltage-time function V(t) and the resulting current?time function I(t):Z=V(t)I(t)=1Y=V0 sin(2��ft)I0 sin(2��ft+��)where V0 and I0 are the maximum voltage and current signals, f is the frequency, t is time, is the phase shift between the voltage-time and current-time functions, and Y is the complex conductance or admittance.
The impedance is a complex value affected by multiple factors, which is described either by the modulus |Z| and the phase shift or alternatively Inhibitors,Modulators,Libraries by the real part ZR and the imaginary part ZI of the impedance [17].Electrochemical impedance spectroscopy (EIS) is a method that describes the response of an electrochemical cell to a small amplitude Inhibitors,Modulators,Libraries sinusoidal voltage signal as function of frequency [18]. It is an ideal tool for observing the dynamics of biomolecule interactions [19]. The most popular formats for evaluating EIS data are the Nyquist and Bode plots. In the Nyquist plot, the imaginary impedance component (z��) is plotted Carfilzomib against the real impedance component (z��).

In another work [8], Lopez, Artes and Alejandre analyze possible

In another work [8], Lopez, Artes and Alejandre analyze possible causes of sources errors when the encoder either is working Inhibitors,Modulators,Libraries under vibrations from a mechanical point of view.Another point of view to improve the accuracy of the sensor is that just based on error compensation from signal processing techniques. Sensor’s Inhibitors,Modulators,Libraries error compensation techniques based on signal processing Inhibitors,Modulators,Libraries constitutes a widely studied research field. The main reason for this lies on the fact that significant improvements of accuracy can be obtained normally at a lower cost than that associated to the introduction of mechanical modifications in the encoder design. There are several methodologies to accomplish encoder’s error compensation [9]: Autocalibration, Look Up Tables (LUT), Filtering, Neural Networks [10], Wavelets and Blocking Amplifiers.
Autocalibration and LUT techniques are of special interest for the purposes of the present work. Probably, Inhibitors,Modulators,Libraries the most referenced technique dealing with autocalibration is that proposed by Heydemann [11]. Basically, the problem is solved introducing in the measurement signals the parameters which produce the encoder metrological errors, arranging the equations in a least squares problem. More recently, Balemi [12] takes this method as a basis to formulate the problem with high computational efficiency to be implemented as an on-line error compensation technique by means of electronic signal processing components. Another point of view to accomplish the compensation has its basis on fitting techniques to the Lissajous figure composed of the deteriorated measurement signals.
Lepple [13] studies the possibility of implementing this technique as an online interpolation procedure for encoders working at high speed. Fitting techniques have also been applied successfully to other position instruments such as interferometers GSK-3 [14]. This methodology contrasts with LUT techniques in the sense that the sensor does not need of any reference to increase its accuracy. Habitually, the elaboration of a LUT implies the use of a sensor of higher accuracy and resolution than the sensor that is going to be compensated [15]. The main advantage of LUT methodologies is that they are easily implemented as on-line procedures due to their high computational efficiency. A similar work close in aim and method to the cited paper [15] is that proposed by Boggarpu et al.
[16], with the difference that no reference sensor is needed and the implementation can be done in a simple cisplatin dna microcontroller rather than more specialized hardware. In this sense, the work developed by de Santiago-Perez et al. [17] remarks the special need for processing encoder’s signals at a low computational cost while maintaining certain level of smoothness in the successive derivations of position up to jerk, in order to allow on-line implementation in obtaining the dynamics parameters from a machine-tool axis.

Various strategies aimed at enhancing gas

Various strategies aimed at enhancing gas Erlotinib sensing characteristics such as gas response and selectivity Inhibitors,Modulators,Libraries have been reported for n-type oxide semiconductors, which include control of the grain size [6,7], morphologies [8], charge carrier concentration [9], catalytic additive(s) [10], and inter-nanostructure contacts [11] of the sensing materials. The results of these studies suggest that selecting additives that can change the charge carrier concentration, catalytic function, and morphology is very advantageous for enhancing or modifying their gas sensing characteristics. However, studies on the gas sensing characteristics of p-type oxide semiconductors are in their early stages, and most researchers have reported on the gas sensing characteristics of pure p-type oxide semiconductors without additives.
Inhibitors,Modulators,Libraries For example, the design of highly sensitive and selective CuO sensors using oxide Inhibitors,Modulators,Libraries additives has barely been investigated. In contrast, the gas sensing characteristics of various undoped CuO nanostructures including thin films [12,13], nanoparticles [14�C16], nanowires [17�C19], nanorods [20], nanoribbons [21], nanosheets [15], worm-like structures [22], and hierarchical structures [23] have been studied extensively.In this study, highly crystalline CuO nanosheets, Cr-doped CuO nanosheets, Inhibitors,Modulators,Libraries and Cr-doped CuO nanorods were prepared by a facile chemical route without using a surfactant or capping agent, and their gas sensing characteristics were studied. The doping of CuO nanostructures with Cr significantly enhanced their response and selectivity toward NO2.
The main focus of this study was investigating the reasons for the enhanced response and selectivity toward NO2 in relation to the Cr-doping-induced changes in the morphology, surface AV-951 area, resistance in air, and catalytic property.2.?Experimental Section2.1. Preparation of CuO and Cr-Doped CuO NanostructuresCuO nanosheets were prepared by the following procedure: CuCl2?2H2O (17.05 g, >99%, Kanto Chemical, Japan) was dissolved in deionized water (100 mL). Then, 50% NaOH aqueous solution (32 g, Samchun Chemical, Korea) was instantaneously poured into the solution, which caused the precipitation of bright blue Cu hydroxide. The precipitate slurry was heated to 100 ��C at a heating rate of 1.67 ��C/min. Then, the temperature of the slurry solution was maintained at 100 ��C for 30 min.
During the reaction, the bright blue Cu-hydroxide GW 572016 precipitate was converted into dark brown CuO nanosheets. CuO nanostructures doped with Cr were prepared by the following procedure: CuCl2?2H2O (17.05 g) and CrCl3?6H2O (0.267 g or 0.799 g, >98%, Aldrich, USA) were dissolved in deionized water (100 mL). 50% NaOH aqueous solution (32 g) was instantaneously poured into the solution. The hydroxide precursors were converted into dark brown Cr-doped CuO nanostructures by heating the precipitate slurry solution at 100 ��C for 30 min.

Endocrine disrupting compounds are organic compounds that can cau

Endocrine disrupting compounds are organic compounds that can cause negative effects on the endocrine systems of humans and wildlife. The release of BPA into the selleck inhibitor environment can be through leakage from plastic packaging into water or food. This leakage is caused by heat and acidic or basic conditions which accelerate the hydrolysis of the ester bonds linking BPA monomers [1].The economic importance of phenols has resulted in the development of many methods for their detection and quantification [4]. However, owing to some advantages Inhibitors,Modulators,Libraries such as low cost and miniaturisability, phenol sensing using electrochemical transducers has been widely studied [5,6]. The electroanalysis of phenols and substituted phenols is possible due to the oxidation of the electroactive phenolic group [7,8].
The electrochemical detection of BPA on different modified electrodes has been reported in the literature. For example, Li et al. used a glassy carbon electrode (GCE) modified with carboxylated multiwalled carbon nanotubes (MWCNTs) to obtain a detection Inhibitors,Modulators,Libraries limit of 5 nM [9]. A similar work using gold nanoparticle (AuNPs) impregnated MWCNTs was reported earlier by Tu et al. [10]. In another study, BPA has been detected using a pencil graphite electrode modified with polyaniline nanorods and MWCNTs [11]. These reports were all based on some modified form of a carbon based electrode.The major problem with electrochemical detection of phenols (including BPA) is electrode fouling which results from phenol polymerisation [5,6,9].
The most common way of dealing with electrode fouling problems is to modify the electrode surface or use composite materials containing nanoparticles with electrocatalytic behaviour [6,9]. However, fouling still Inhibitors,Modulators,Libraries occurs and this affects the sensitivity, reusability and reproducibility of the electrode. When using modified electrodes for the detection of phenolic compounds, the electrode is usually polished and re-modified Inhibitors,Modulators,Libraries again for every new measurement. This modification step Entinostat (e.g., drop-dry or dip-coating methods) usually increases the analysis time [10,11]. Hence in this study, we present a low cost bare exfoliated graphite (EG) electrode, possessing a surface that can be renewed with good reproducibility, as a way of tackling the problem of fouling in BPA detection.Exfoliated graphite is a low density material produced from graphite.
It has good electrochemical properties and can be easily compressed for electrode fabrication [12]. Although EG electrodes have been available for some time now, there are currently no reports on the our website use of these cheap electrodes for the electroanalysis of water pollutants�Can attempt which we have made in this report.2.?Experimental Section2.1. MaterialsNatural graphite and bisphenol A (BPA) were obtained from Sigma Aldrich while KH2PO4, K2HPO4, CH3CN, H3PO4 and NaOH were purchased from Merck Chemicals.

olic activity of differentiating human NPCs, we tested the abilit

olic activity of differentiating human NPCs, we tested the ability of mitochondrial dehydrogenases to cleave the substrate Wst 1, a tetrazolium salt derivative as a mea sure of metabolic activity selleck kinase inhibitor in presence of different Inhibitors,Modulators,Libraries concen trations of EPO. ReNcell VM cells were incubated under differentiation conditions for 1 day and 3 days in the presence and absence of EPO, respectively. During differentiation EPO caused a significant increase of metabolic activity after 1 day under normoxic condi tions from a concentration of 25 IU ml on and higher compared to control. A similar increase of the metabolic activity was observed at 3% O2, but higher EPO concentrations were needed for a significant change of activity.

The signifi cant increase of the metabolic activity caused by EPO was not any longer present after 3 d of differentiation in both conditions normoxia and hypoxia as seen in Fig ure 4C and 4D. By comparing the control values of both conditions, one can see a significant Inhibitors,Modulators,Libraries increase of the meta bolic activity at 3% oxygen at both time points of differ entiation, indicating a general influence of low oxygen on the cell metabolism which lasts for several days during differentiation. For comparison the Wst 1 assay at 1 d and 3 d of proliferating cells is shown in Fig ure 4F. Consistently, hypoxia increased the metabolic activity in this condition. Lowered oxygen promotes neuronal differentiation of NPCs Next, we investigated the effect of lowered oxygen on the neuronal differentiation of human NPCs. After the withdrawal of growth factors, ReNcell VM cells were either differentiated at 20% or 3% oxygen for 4 days.

First we asked the question, whether the differences of the differentiation between 20% O2 and 3% O2 is caused by changes of the Inhibitors,Modulators,Libraries proportions of cells in Inhibitors,Modulators,Libraries each cell cycle phase. Therefore we performed cell cycle measurements with flow cytometry, using the DNA binding dye propi dium iodide. Figure 5 shows the percentage of cells within the phases of the cell cycle within the first 24 h of differentiation. After 20 hours, 95% of the cells reached G1 G0 phase, both in normoxic as well as in hypoxic conditions. To verify neuronal differentiation, the expression of bIII tubulin was measured by FACS analysis. For these experiments we included additional culturing conditions. First, the cells proliferated at 20% oxygen and were dif ferentiated at either 20% or 3% oxygen.

Sec ond, the cells were expanded at 3% and differentiated at 20% or 3% oxygen, respectively. In addition, EPO was applied at 10 IU ml and 100 IU ml with the onset GSK-3 of differentiation. As shown in Figure 5C, there is no difference in the percentage of bIII tubulin positive cells between 20% and 3% oxygen and also no influence of EPO until day 3 of differentiation. HTS At this time point, the maximal number of neurons appears with an almost twofold increase of the percen tage of bIII tub cells under hypoxic conditions with 4. 51 0. 45% compared to 2. 61 0. 31%. At day 4 of dif ferentiation, th