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Energy devices with high energy/power density are the need of the day, and to achieve the same, electrolytes with faster ion transport and wider electrochemical stability window are required. Polymer-in-salt electrolytes (PISEs) are predicted to have the better required electrochemical properties in comparison to salt-in-polymer electrolytes (SIPEs), but desired success is still to be achieved due to recrystallization problems. PISEs suffer from poor mechanical and/or electrochemical properties along with aging effects as well; hence, special efforts are required to reduce the crystallinity of PISEs. The present paper discusses a crosslinked corn starch complexed with Mg(ClO4)2 which not only has desired electrochemical properties but is also flexible. XRD study confirms the absence of crystalline nature, without any extra efforts to reduce it. Synthesized PISEs have high conductivity (~0.01 Scm−1), wide ESW (> 3 V), and low relaxation time (µs) along with being economical. Supercapacitors fabricated using this novel PISE with laboratory synthesized activated carbon (from leaves and corn starch) have shown good specific capacitance (~ 20 Fg−1 and ~ 45 Fg−1, respectively). The power density is of the order of kW kg−1, which is quite high in comparison to other reports. The shape of CV and LSV is strongly influenced by the salt concentration, i.e., by the ion-cluster size, and is also affected by the volume/size of the activated carbon pores. [ABSTRACT FROM AUTHOR]

In the 1990s, polymer-in-salt electrolytes (PISEs) came into the picture with the hope to overcome the problem of slow ion motion and low cation transference number in salt-in-polymer-electrolytes (SIPEs). The present paper reports an electrolyte membrane in the PISE range using renewable polymer (rice starch), synthesized using a simple solution cast technique having high moisture content (~ 12%). The synthesized flexible PISE membrane has high conductivity (~ 10−2 S/cm) and fast ion transport (relaxation time ~ µs). Conductivity is almost independent of relative humidity indicating the water molecules available in the matrix are involved in the lattice formation and the matrix is stable. X-ray diffraction (XRD) analysis and optical photographs have confirmed that the crosslinked starch matrix accepts a large amount of salt, and even at 300 wt% of salt (i.e., at 3:1 salt: starch ratio), morphology remains homogenous, and no signature of salt is present in XRD spectra. The electrochemical stability window (ESW ~ 2.7 V) is also wide enough for energy device fabrication. To check its potential for supercapacitor application, the two most simple electrodes (anodized Al and carbon cloths) were selected. The approximate rectangular shape of cyclic voltammetry (CV) performed at different scan rates from 5 to 500 V/s, indicated the EDLC-type charge storage phenomenon in the studied voltage ranges. For scan rate above 300 V/s, the capacitance value is almost independent of scan rate. All these indicate that crosslinked starch-based PISEs are a successful step towards the target for possibilities of commercial application of polymer-in-salt electrolytes. [ABSTRACT FROM AUTHOR]

In this paper, Silicon-on-Insulator vertical TFET based CMOS high-speed switch is implemented on Full-duplex Cognitive Radio (FD-CR), and the impact of cognitive radio (CR) node mobility on the performance of a full-duplex (FD) system is investigated under imperfect channel estimation. In this regard, a vertical SOI CMOS structure is designed, and its performance parameters are investigated, and then it is employed in the FD system. The mobile CRs are considered, and the channel between primary transmitter (PT) and CRs is time selective due to node mobility. Jake's model is used to model CR node mobility. Here, the energy detection (ED) technique is used for spectrum sensing. The expressions for the false alarm and detection probabilities have been obtained, considering the sensing and residual self-interference (RSI) channel as Nakagami-m distributed. We got the receiver operating characteristic (ROC) curve, an area under the ROC (AUC) curve, and the total error rate (TER) under perfect CSI, imperfect CSI, and node mobility at the receiver. Monte Carlo simulation is given to validate all of the analytical findings. [ABSTRACT FROM AUTHOR]

In this manuscript, 60 nm CMOS is designed using Vertical TFETs structures and its ID-VGS is investigated. Then, the designed structure is utilized to implement the single-channel in-band full-duplex (SC-IBFD) radio receiver. The full-duplex cognitive radio (FD-CR) device performs the sensing and transmission in a single channel at the same time and frequency. Here, the FD-CRs are considered to be stationary, and the channel between the primary transmitter (PT) and the cognitive radios (CRs) is Nakagami-m distributed fading. The influence of channel state information (CSI) estimation error on the performance of SC-IBFD radio receiver is investigated. The energy detection (ED) approach is utilised for spectrum sensing. The expressions for the false alarm and detection probability were calculated under the Nakagami-m distribution for the sensing and residual self-interference (RSI) channels. Finally, under perfect CSI and imperfect CSI, the receiver operating characteristic (ROC) curves are obtained. The total error rate (TER) and the area under the ROC (AUC) curve are also obtained at the receiver. All of the analytical findings are validated using Monte Carlo simulation. [ABSTRACT FROM AUTHOR]

The demand for more bandwidth is increasing day by day due to explosive growth in data generated on account of services enabled on mobile phone, laptops and IOT devices. In the near future Internet for everything (IoE) technology where social media, processes, big data etc. will require internet connectivity all the times. Filter bank multicarrier with offset quadrature amplitude modulation system (FBMC/OQAM) is one of the promising techniques for next generation wireless communication system (5G). In FBMC-OQAM orthogonality condition is relaxed to obtain, better bandwidth utilization. This FBMC-OQAM is a multi-carrier transmission scheme where sub-carriers are independent to each other in time domain. The composite signal has large variation in amplitude, thus lead to peak to average power variation problem. This paper presents a FBMC scheme based on DFT spread and identically time shifted multicarriers (ITSM) conditions. In the chosen scheme DFT and IDFT is performed once and system behave as a nearly single carrier. This paper also deals with, PAPR reduction scheme. The chosen scheme is based on clipping and non-liner companding scheme, and obtained results are compared with recently proposed method. [ABSTRACT FROM AUTHOR]

Objectives: ATP-binding cassette transporter A1 (ABCA1) is a key player in the reverse cholesterol transport (RCT) and HDL biogenesis. Since RCT is compromised as a result of ABCA1 dysfunction in diabetic state, the objective of this study was to investigate the regulation of ABCA1 in a stably transfected 293 cells expressing ABCA1 under the control of cAMP response element. Methods: To delineate transcriptional and posttranscriptional regulation of ABCA1, 293 cells were stably transfected with the full length ABCA1 cDNA under the control of CMV promoter harboring cAMP response element. cAMP-mediated regulation of ABCA1 and cholesterol efflux were studied in the presence of 8-Br-cAMP and after withdrawal of 8-Br-cAMP. The mechanism of cAMP-mediated transcriptional induction of the ABCA1 gene was studied in protein kinase A (PKA) inhibitors-treated cells. Results: The transfected 293 cells expressed high levels of ABCA1, while non-transfected wild-type 293 cells showed very low levels of ABCA1. Treatments of transfected cells with 8-Br-cAMP increased ABCA1 protein by 10-fold and mRNA by 20-fold. Cholesterol efflux also increased in parallel. Withdrawal of 8-Br-cAMP caused time-dependent rapid diminution of ABCA1 protein and mRNA, suggesting ABCA1 regulation at the transcriptional level. Treatment with PKA inhibitors abolished the cAMP-mediated induction of the ABCA1 mRNA and protein, resulting dampening of ABCA1-dependent cholesterol efflux. Conclusions: These results demonstrate that transfected cell line mimics cAMP response similar to normal cells with natural ABCA1 promoter and suggest that ABCA1 is a short-lived protein primarily regulated at the transcriptional level to maintain cellular cholesterol homeostasis. [ABSTRACT FROM AUTHOR]

Secure data communication is the need of hour today specifically when the wireless communication channel is insecure. We are proposing a protocol which can be customized in variety of situations. We want to use steganography as a complementary tool for cryptography. The protocol utilizes the nature of communication protocol and it is even useful for places where data hiding and cryptography is illegal or can't be performed because of various reasons. We are giving a name to these kinds of networks as disturbed networks. The proposed peer to peer protocol is very useful for insecure channels and disturbed networks and we provide complete analysis to validate its utility. The method is a convenient stop and wait protocol which provides unbeatable security and suitable for mobile phones as well. At the same time, for intruder's perspective, there is no encryption involved which is a very important aspect. [ABSTRACT FROM AUTHOR]

Being eco-friendly, cost-effective, easy to synthesize and handle, starch-based electrolytes have tremendous advantages for electrochemical device fabrications. Starch electrolytes synthesized by crosslinking process result in stable, flexible, free-standing films which can be molded in different shapes and sizes. Rice starch–based material, prepared using glutaraldehyde as crosslinker and NaClO4 as ion-providing salt, resulted in high conductivity (~ 0.01 S/cm) and fast-relaxing (ion relaxation time in micro seconds) electrolytes having wide electrochemical stability window (~ 3 V). Resistance of highest conducting sample, having 0.8 mm thickness and 1 × 1 cm2 area is ~ 6 Ω. The synthesized electrolyte is easily moldable in desired shape and size and hence devices may be fabricated with smaller equivalent series resistance. The estimated relaxation time is 62 μs indicating that fabricated devices will be able to deliver energy in shorter time. The approximate preparation cost of the material (1 × 1 × 0.08 cm3) is INR 20 (~ 0.3USD). The low cost, good technical parameters, and flexibility make it a promising material for electrochemical device fabrication. [ABSTRACT FROM AUTHOR]

An environment friendly coupled mode surface plasmon resonance sensor structure with starch biofilm as sensing element for humidity detection of environment is fabricated and demonstrated. The surface plasmon resonances were created using PVC layer fabricated between silver and starch biofilm on a rectangular prism. The analyses of fabricated sensor have been done by both wavelength and angular interrogation methods. The proposed sensor has maximum sensitivity 0.45 nm/%RH in wavelength interrogation method and 0.09°/%RH in angular interrogation method. Here the variations in humidity of environment, changes the refractive index of starch biofilm and hence in the surface plasmon resonances. Also, the proposed sensor shows a linear variation in resonance wavelength and resonance angle with respect to the variation in humidity of environment. [ABSTRACT FROM AUTHOR]

Energy storage devices are the lifeline of today's society, and hence, researchers are trying to achieve 3Es (economical, environment friendly, and easy to prepare) along with other required technical data. Here, a new wheat starch + NaI system is synthesized which not only have good technical data such as high ionic conductivity (3.61 × 10 S/cm), very low dielectric relaxation time (13.2 μs), and wide electrochemical stability window (2.6 V) but it also satisfies 3Es conditions because it uses starch which is very cheap and abundant biopolymer available in large variety. The approximate cost of preparing 1 cm of the sample is approximately INR 15. The prepared material is flexible, free standing film which can be easily stretched to 1.9 times to its length, and can be easily twisted up to 90°. The phase angle value approaches to −73° and maintains its value from 10 Hz to 9 kHz frequency range. The ESR value (of sample having thickness 0.48 mm and area 1.21 cm) is very low (1.10 Ω). Parallel capacitance (C) to series capacitance (C) ratio is >0.9, and the value is maintained up to a wide frequency range (10 Hz to 10 kHz). Self-resonance frequency (the frequency limit below which energy can be stored efficiently) is also quite high (0.1 MHz) for the present system. Hence, the studied system is a potential candidate for future electrochemical applications. [ABSTRACT FROM AUTHOR]

Energy devices are the lifeline of today's society, and hence, they are produced in large number resulting in tremendous increase of chemical garbage. Hence, the scientific community is thoroughly looking for eco-friendly alternatives for sustainable development. Polymer electrolytes have received greater attention, and their biodegradable/eco-friendly substitutes are being studied in many laboratories. Starch, being low cost, eco-friendly, and abundant in nature, has attracted many scientists. In our laboratory, crosslinked starches (arrowroot, corn, wheat, and rice) are being used for electrolyte preparation. Present paper discusses the results of arrowroot starch crosslinked with glutaraldehyde and complexed with NaI. The highest conductivity was found to be of the order of 10 S/cm. In these systems, conductivity goes on increasing starch/salt ratio up to 1:1 which can be correlated with salt plasticization effect. Phase angle remains above −75° for nearly 3 orders of frequency. The estimated ion relaxation time is 14 μs, and the equivalent series resistance is ∼3 Ω which indicates fast ion response. C/C ratio remains ∼1 for 4 order of frequency. Such behavior indicates that these materials are suitable for the fast charging-discharging devices. [ABSTRACT FROM AUTHOR]

Polymer electrolyte has seen tremendous growth after works of Fenton & Armand, and energy devices are being produced at commercial level. Today's social lifestyle needs miniaturized energy devices at every step of life; consequently, they add up to chemical garbage of the world. The sustainable development in the field needs eco-friendly energy devices. Hence, starch (being at low cost, abundant in nature and eco-friendly) has received great scientific attention. In recent past, many attempts have been made to modify the various starches to get fast ion-conducting materials. In our laboratory, also, wheat, potato, rice and arrowroot starches have been modified with different sodium salts, and in each case, considerably high-conducting (>10 S/cm) films have been found. In present case, also, a high-conducting transparent film (10 S/cm) is obtained with corn starch and NaClO salt after being crosslinked with glutaraldehyde (GA). Bode plots (both phase and magnitude), capacitive-response plot, capacitive-frequency plots and linear sweep voltammetry curves are analysed to explain the possibility of using the prepared electrolyte in capacitive device. The larger electrochemical stability window (ESW) ~ 2.4 V and smaller ion relaxation time ~ 65 μs make it a potential candidate for device fabrication. The equivalent series resistance is ~6.252 Ω for 0.8-mm-thick sample. [ABSTRACT FROM AUTHOR]

The present paper discusses the ion dynamics of a novel polymeric system prepared by doping of NaPF in a lab-prepared polymer matrix. Ion dynamics of the system is analyzed by presenting the impedance data in different formalisms. Mobility (and hence the conductivity) continuously increases with salt concentration, and the phenomenon is correlated with salt's plasticization nature, which is reconfirmed by the shifting of minima in ∂log ε′/∂log ω vs. log ω curve towards high frequency. It has been observed that number of charge carriers ( N′) estimated from conductivity data do not represent the real charge concentration in the system. Within the experimental frequency (∼MHz) range, three different regions are identified in ∂log σ vs. ∂log ω curves namely (i) dc conductivity/free hopping, (ii) correlated ion hopping, and (iii) caged movement of ions. In the present case, also a scaled master conductivity curve is obtained by estimating the σ and ω (exclusively in Jonscher Power Law or JPL region) according to our previously proposed method. Scaling is realized with respect to salt concentration and temperature, which is an indication that salt concentration and temperature are only governing the number of charge carriers and mobility without affecting the underlying ion transport mechanism. Non-Debye-type relaxation phenomenon is indicated by KWW exponent β (<1). Relaxation times, obtained from tan δ vs. log ω curves, inversely follow the conductivity, indicating strongly correlated ion-polymer segmental motions. [ABSTRACT FROM AUTHOR]

Conductivity and dielectric behavior of a synthesized NHI-doped polymeric electrolytes are discussed in terms of σ, N/ N, permittivity, loss factor, modulus, and Kohlrausch-Williams-Watts (KWW) exponent β, with the variation of salt concentration and temperature. System, having 50 wt% salt, has maximum conductivity (∼10 S cm). Addition of salt modifies the system from semicrystalline to amorphous which is further supported by peak shift in ∂logε′/∂logω vs logω curve. β follows the number of charge carrier's pattern, with salt concentration. Collective analysis of impedance, dielectric, and modulus spectroscopy indicated a strong coupling between ion and polymer segmental motion, but at 50 % salt concentration, they are decoupled. Relaxation time analysis has affirmed this correlation. Merging tendency of logσ vs logω isotherms, for different salt concentrations and temperatures, at higher frequency indicates the dominance of superlinear power law phenomenon, even at room temperature, in megahertz frequency range. [ABSTRACT FROM AUTHOR]

New polymer-salt systems have been prepared by doping synthesized poly( N-phenylene N′imino pentyl) imminium propane sulfonate with NaPF and NaCl. The higher conductivity of the NaPF-doped system in comparison to the NaCl-containing sample indicated that a larger-sized anion is facilitating ion conduction. FTIR spectra confirmed the complexation of salt with polymer. The conductivity power law exponent, studied in the frequency range from 42 Hz to 5 MHz, varies with frequency and has values >1, demonstrating dominance of caged ion movement. The dominance of caged motion is more pronounced in the NaCl-doped sample, signifying that a smaller anion has greater chances of being caged. Anion size signature is also visible in temperature and humidity dependence of exponent n. [ABSTRACT FROM AUTHOR]

biopolymer electrolyte system having conductivity ∼1.3 × 10 S cm has been prepared using potato starch, NaI, glutaraldehyde and poly(ethylene glycol) (PEG; molecular weight = 300). High ionic transference numbers (∼0.99) of the material confirmed its electrolytic behaviour. Conductivity and dielectric behaviour as a function of frequency has been studied. Conductivity follows 'universal power law' ( σ = σ + Aω) with exponent ' n' varying from 0.94 to 1.18. Cross-linking and plasticization increases long pathways motion of charge carriers, comparable to sample dimension. Humidity-independent behaviour (up to 80% relative humidity), of impedance and water intake by the system, indicates the system's potentiality as a promising candidate for humidity immune device fabrication. The addition of PEG has a twofold effect on the material's conductivity. It not only increases conductivity but also improves the material's immunity towards humid atmosphere. [ABSTRACT FROM AUTHOR]

ATP-binding cassette transporter A1 (ABCA1) was recently recognized as the mutant molecule responsible for Tangier disease with low HDL levels, accumulation of cholesteryl esters in tissues, and increased risk of cardiovascular disease. Extensive studies for the past 2 years have recognized the critical role of ABCA1 in cholesterol and phospholipid trafficking. Since the removal of cholesterol from tissues is a key step in the prevention of atherosclerosis, significant attention has been focused on this molecule. Natural ABCA1 mutations in Tangier disease (TD) patients and WHAM chickens together with induced mutation in ABCA1 knock-out mice unequivocally established the important role of ABCA1 in maintaining circulating HDL levels and promoting cholesterol efflux from the arterial wall. Mice lacking ABCA1 showed similar phenotypes observed in Tangier disease patients with low levels of HDL. Further understanding of the roles of ABCA1 in lipid transport and atherosclerosis became clear from studies with ABCA1 transgenic mice. These mice showed enhanced cholesterol efflux from macrophages and reduced atherosclerotic lesion formation. The promoter of the ABCA1 gene has been mapped to a large extent, with the exception of cAMP response element. The present review summarizes recent developments on the role of ABCA1 in cholesterol efflux and prevention of atherosclerosis. Given the antiatherogenic properties of ABCA1, this molecule can serve as an appropriate target for developing drugs to treat individuals with low levels of HDL. [ABSTRACT FROM AUTHOR]

We have shown mouse to be an useful animal model for studies on the estrogen-mediated synthesis and secretion of lipoproteins since, unlike in rats, low density lipoprotein receptors are not upregulated in mice [3]. This results into the elevation of plasma levels of apolipoprotein (apo) B and apoE, and lowering of apoA-I-containing particles. The mechanisms of apoB and apoE elevation by estrogen have been elucidated [6], but the mechanism of lowering of plasma levels of HDL is still not known. Among other factors, apoA-I, cholesterol ester transfer protein (CETP), scavenger receptor B1 (SR-B1), and hepatic lipase are potential candidates that modulate plasma levels of HDL. Since estrogen treatment increased hepatic apoA-I mRNA and apoA-I synthesis, and mouse express undetectable levels of CETP, we tested the hypothesis that estradiol-mediated lowering of HDL in mice may occur through modulation of hepatic lipase (HL). Four mouse strains (C57L, C57BL, BALB, C3H) were administered supraphysiological doses of estradiol, and plasma levels of HDL as well as HL mRNA were quantitated. In all 4 strains estradiol decreased plasma levels of HDL by 30%, and increased HL mRNA 2–3 fold. In a separate experiment groups of male C57BL mouse were castrated or sham-operated, and low and high doses of estradiol administered. We found 1.4–2.5 fold elevation of HL mRNA with concomitant lowering of HDL levels. Ten other mouse strains examined also showed estradiol-induced elevation of HL mRNA, but the extent of elevation was found to be strain-specific. Based on these studies, we conclude that hepatic lipase is an important determinant of plasma levels of HDL and that HL mRNA is modulated by estrogen which in turn may participate in the lowering of plasma levels of HDL. [ABSTRACT FROM AUTHOR]

High density lipoproteins (HDL), one of the main lipoprotein particles circulating in plasma, is involved in the reverse cholesterol transport. Several lines of evidence suggest that elevated levels of HDL is protective against coronary heart disease. The role of HDL in the removal of body cholesterol and in the regression of atherosclerosis add to the importance of understanding the molecular-cellular processes that determine plasma levels of HDL. Factors modulating plasma levels of HDL may have influence on the predisposition of an individual to premature coronary artery disease. Apolipoprotein (apo) A-I is the main apolipoprotein component of HDL and, to a large extent, sets the plasma levels of HDL. Thus, understanding the regulation of apoA-I gene expression may provide clues to raise plasma levels of HDL. This review discusses the various pathways that alter plasma levels of HDL. Since apoA-I is the main protein component of HDL and determines the plasma levels of HDL, this review also covers the regulation of apoA-I gene expression. [ABSTRACT FROM AUTHOR]

Energy devices with high energy/power density are the need of the day, and to achieve the same, electrolytes with faster ion transport and wider electrochemical stability window are required. Polymer-in-salt electrolytes (PISEs) are predicted to have the better required electrochemical properties in comparison to salt-in-polymer electrolytes (SIPEs), but desired success is still to be achieved due to recrystallization problems. PISEs suffer from poor mechanical and/or electrochemical properties along with aging effects as well; hence, special efforts are required to reduce the crystallinity of PISEs. The present paper discusses a crosslinked corn starch complexed with Mg(ClO4)2 which not only has desired electrochemical properties but is also flexible. XRD study confirms the absence of crystalline nature, without any extra efforts to reduce it. Synthesized PISEs have high conductivity (~0.01 Scm−1), wide ESW (> 3 V), and low relaxation time (µs) along with being economical. Supercapacitors fabricated using this novel PISE with laboratory synthesized activated carbon (from leaves and corn starch) have shown good specific capacitance (~ 20 Fg−1 and ~ 45 Fg−1, respectively). The power density is of the order of kW kg−1, which is quite high in comparison to other reports. The shape of CV and LSV is strongly influenced by the salt concentration, i.e., by the ion-cluster size, and is also affected by the volume/size of the activated carbon pores. [ABSTRACT FROM AUTHOR]

Low levels of cholesterol are protective against development of coronary artery disease. Heterozygous hypobetalipoproteinemic individuals expressing truncated apolipoprotein (apo)B as a result of mutation in the capob gene have low levels of cholesterol and apoB in their plasma. To study the molecular mechanism of low levels of apoB in these individuals, we employed a previously reported knock out mouse model generated by targeted modification of the apob gene. The heterozygous, apoB-100/B-81, mice express full length and truncated apoB, B-81, and have 20 and 35% lower levels of total cholesterol and apoB, respectively, when compared to WT (apoB-100/B-100) mice. The majority of the truncated apoB, B-81, fractionated in the VLDL- density range. The mechanism of low levels of apoB in B-100/B-81 mice was examined. Total hepatic apoB mRNA levels decreased by 15%, primarily due to lower levels of apoB-81 mRNA. Since apoB mRNA transcription rates were similar in B-100/B-100 and B-100/B-81 mice, low levels of mutant apoB-81 mRNA occurred by enhanced degradation of apoB mRNA transcript containing premature translational stop codon. ApoB synthesis measured on isolated hepatocytes decreased in B-100/B-81 mice by 35%, while apoB-48, apoE, and apoAI syntheses remained unchanged. Metabolic studies using whole animal showed a 32% decrease in triglyceride secretion rates, consistent with the apoB secretion rates. Inhibition of receptor-mediated clearance of apoB-81-containing particles resulted in greater relative accumulation of apoB-81 in plasma than apoB-100, suggesting enhanced clearance of apoB-81-containing particles. These results demonstrate that low levels of apoB in heterozygous hypobetalipoproteinemic mice occurs by low rates of apoB secretion, and increased clearance of truncated apoB. Similar mechanisms appear to contribute to low levels of apoB in hypobetalipoproteinemic humans. [ABSTRACT FROM AUTHOR]

Objective:Creative kinase (CK) isoenzymes play an important role in cellular energy transduction. Two isoenzymes of creatine kinase, ubiquitous mitochondrial creatine kinase (uMtCK) and cytosolic brain creatine kinase (BCK), are postulated to form the creatine phosphate (CP) shuttle, in which creatine serves to transport high-energy phosphate from the mitochondria to its site of utilization. Coordinate regulation of these genes is essential for efficient energy transduction. We examined human CK isoenzyme regulation in placentas during all three trimesters of gestation to define the mRNA and protein expression patterns of uMtCK and BCK and to test the CP shuttle hypothesis.Methods:Placental samples were collected from a total of 26 patients from the first, second, and third trimesters. Total RNA and protein were prepared from each sample and quantified. Quantitative RNA analysis was performed by gel electrophoresis and dot blot techniques using isoenzyme-specific human cDNA probes for uMtCK and BCK. Protein expression of uMtCK and BCK was examined by Western blot analysis using isoenzyme-specific antibodies to uMtCK and BCK.Results:Analysis of RNA demonstrated the coordinate expression of uMtCK and BCK mRNAs in human placenta, with peak expression ofboth in the term placentas. Western blot analysis demonstrated coordinate expression of uMtCK and BCK proteins in the first and second trimesters, but not in the term placenta. Expression levels of uMtCK and BCK proteins were not consistent with their respective mRNA levels in the term placenta.Conclusion:Expression of uMtCK and BCK in human placenta is highly regulated, and posttranscriptional regulation of uMtCK and BCK expression occurs in the term placenta. The coordinate regulation of uMtCK and BCK in human placenta supports the CP shuttle hypothesis. This analysis demonstrates that human placenta has high energy needs that can change rapidly; thus, a functioning CP shuttle may be important in the maintenance and termination of pregnancy. [ABSTRACT FROM PUBLISHER]