Search

Abstract Objective To address the challenge of assessing sedation status in critically ill patients in the intensive care unit (ICU), we aimed to develop a non-contact automatic classifier of agitation using artificial intelligence and deep learning. Methods We collected the video recordings of ICU patients and cut them into 30-second (30-s) and 2-second (2-s) segments. All of the segments were annotated with the status of agitation as “Attention” and “Non-attention”. After transforming the video segments into movement quantification, we constructed the models of agitation classifiers with Threshold, Random Forest, and LSTM and evaluated their performances. Results The video recording segmentation yielded 427 30-s and 6405 2-s segments from 61 patients for model construction. The LSTM model achieved remarkable accuracy (ACC 0.92, AUC 0.91), outperforming other methods. Conclusion Our study proposes an advanced monitoring system combining LSTM and image processing to ensure mild patient sedation in ICU care. LSTM proves to be the optimal choice for accurate monitoring. Future efforts should prioritize expanding data collection and enhancing system integration for practical application.

During the operation of the lithium batteries, due to energy loss, the heat will be generated. Therefore, effective heat dissipation technique is required for operation of the lithium batteries under the safe temperature limit. To increase the safety, efficiency, and lifetime of these batteries, the thermal management is an important key factor. Nickel cobalt lithium manganate (NCM) batteries have high energy ratio and high voltage output. The thermal performance of phase change material (PCM) and air cooling system, as a combined cooling system, employed for single battery and battery packs is investigated in this study. NCM-21700 lithium-ion battery is considered for investigation. With boosting DR, the internal temperature of the battery is increased rapidly, and the temperature uniformity is decreased. The analysis of single cell equipped with the PCM showed that the PCM with δ = 12 mm is the best choice at DR = 3C. In addition, it was concluded that under the synergistic effect of air cooling and PCM, since the PCM continuously takes away the heat of the battery, and the air can remove the heat absorbed by the PCM with high rate, the performance of the battery can be improved. The final battery surface temperatures are 30.53°C, 29.97°C, 29.71°C, and 29.93°C for the PCM thicknesses of 5, 10, 12, and 15 mm, respectively. During the discharge process, the battery temperature under the synergistic effect of the air and the PCM increases gently and reaches to 30.6 °C. The PCM cannot fully control the battery temperature change at high discharge rates. The low thermal conduction in PCM leads to the inability to effectively transfer heat to the external surface of the PCM.

Previous research has presented conflicting evidence regarding whether Chinese characters are processed holistically. In past work, we applied Systems Factorial Technology (SFT) and discovered that native Chinese speakers exhibited limited capacity when processing characters and words. To pinpoint the source of this limitation, our current research delved further into the mental architecture involved in processing Chinese characters and English words, taking into consideration information from each component. In our current study, participants were directed to make the same/different judgments on characters/words presented sequentially. Our results indicated that participants utilized a parallel self-terminating strategy when both or neither of the left/right components differed (Experiment 1). Faced with the decisional uncertainty that either the left/right component would also differ, most participants processed with a parallel exhaustive architecture, while a few exhibited the coactive architecture (Experiment 2). Taken together, our work provides evidence that in word/character perception, there is weak holistic processing (parallel self-terminating processing) when partial information is sufficient for the decision; robust holistic processing (coactive or parallel exhaustive processing) occurs under decisional uncertainty. Our findings underscore the significant role that the task and presentation context play in visual word processing.

The Word Superiority Effect (WSE) refers to the phenomenon where a single letter is recognized more accurately when presented within a word, compared to when it is presented alone or in a random string. However, previous research has produced conflicting findings regarding whether this effect also occurs in the processing of Chinese characters. The current study employed the capacity coefficient, a measure derived from the Systems Factorial Technology framework, to investigate processing efficiency and test for the superiority effect in Chinese characters and English words. We hypothesized that WSE would result in more efficient processing of characters/words compared to their individual components, as reflected by super capacity processing. However, contrary to our predictions, results from both the “same” (Experiment 1) and “different” (Experiment 2) judgment tasks revealed that native Chinese speakers exhibited limited processing capacity (inefficiency) for both English words and Chinese characters. In addition, results supported an English WSE with participants integrating English words and pseudowords more efficiently than nonwords, and decomposing nonwords more efficiently than words and pseudowords. In contrast, no superiority effect was observed for Chinese characters. To conclude, the current work suggests that the superiority effect only applies to English processing efficiency with specific context rules and does not extend to Chinese characters.

Summary: Background: Therapeutic hypothermia (TH) is standard of care for moderate to severe neonatal hypoxic ischemic encephalopathy (HIE) but many survivors still suffer lifelong disabilities and benefits of TH for mild HIE are under active debate. Development of objective diagnostics, with sensitivity to mild HIE, are needed to select, guide, and assess response to treatment. The objective of this study was to determine if cerebral oxygen metabolism (CMRO2) in the days after TH is associated with 18-month neurodevelopmental outcomes as the first step in evaluating CMRO2's potential as a diagnostic for HIE. Secondary objectives were to compare associations with clinical exams and characterise the relationship between CMRO2 and temperature during TH. Methods: This was a prospective, multicentre, observational, cohort study of neonates clinically diagnosed with HIE and treated with TH recruited from the tertiary neonatal intensive care units (NICUs) of Boston Children's Hospital, Brigham and Women's Hospital, and Beth Israel Deaconess Medical Center between December 2015 and October 2019 with follow-up to 18 months. In total, 329 neonates ≥34 weeks gestational age admitted with perinatal asphyxia and suspected HIE were identified. 179 were approached, 103 enrolled, 73 received TH, and 64 were included. CMRO2 was measured at the NICU bedside by frequency-domain near-infrared and diffuse correlation spectroscopies (FDNIRS-DCS) during the late phases of hypothermia (C), rewarming (RW) and after return to normothermia (NT). Additional variables were body temperature and clinical neonatal encephalopathy (NE) scores, as well as findings from magnetic resonance imaging (MRI) and spectroscopy (MRS). Primary outcome was the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) at 18 months, normed (SD) to 100 (15). Findings: Data quality for 58 neonates was sufficient for analysis. CMRO2 changed by 14.4% per °C (95% CI, 14.2–14.6) relative to its baseline at NT while cerebral tissue oxygen extraction fraction (cFTOE) changed by only 2.2% per °C (95% CI, 2.1–2.4) for net changes from C to NT of 91% and 8%, respectively. Follow-up data for 2 were incomplete, 33 declined and 1 died, leaving 22 participants (mean [SD] postnatal age, 19.1 [1.2] month; 11 female) with mild to moderate HIE (median [IQR] NE score, 4 [3–6]) and 21 (95%) with BSID-III scores >85 at 18 months. CMRO2 at NT was positively associated with cognitive and motor composite scores (β (SE) = 4.49 (1.55) and 2.77 (1.00) BSID-III points per 10−10 moL/dl × mm2/s, P = 0.009 and P = 0.01 respectively; linear regression); none of the other measures were associated with the neurodevelopmental outcomes. Interpretation: Point of care measures of CMRO2 in the NICU during C and RW showed dramatic changes and potential to assess individual response to TH. CMRO2 following TH outperformed conventional clinical evaluations (NE score, cFTOE, and MRI/MRS) at predicting cognitive and motor outcomes at 18 months for mild to moderate HIE, providing a promising objective, physiologically-based diagnostic for HIE. Funding: This clinical study was funded by an NIH grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, United States (R01HD076258).

IntroductionLiterature is limited on quantified acute stress reaction, the impact of event scale on medical staff when facing medical malpractice (MMP), and how to individually care for staff.MethodsWe analyzed data in the Taichung Veterans General Hospital from October 2015 to December 2017, using the Stanford Acute Stress Reaction Questionnaire (SASRQ), the Impact of Event Scale-Revised (IES-R), and the medical malpractice stress syndrome (MMSS).Results and DiscussionOf all 98 participants, most (78.8%) were women. Most MMPs (74.5%) did not involve injury to patients, and most staff (85.7%) indicated receiving help from the hospital. The internal-consistency evaluations of the three questionnaires showed good validity and reliability. The highest score of IES-R was the construct of intrusion (30.1); the most severe construct of SASRQ was “Marked symptoms of anxiety or increased arousal,” and the most were having mental and mild physical symptoms for MMES. A higher total IES-R was associated with younger age (

MicroRNAs (miRNAs) can regulate the expression of genes involved in the establishment of the window of implantation (WOI) in the endometrium. Recent studies indicated that cell-free miRNAs in uterine fluid and blood samples could act as alternative and non-invasive sample types for endometrial receptivity analysis. In this study, we attempt to systematically evaluate whether the expression levels of cell-free microRNAs in blood samples could be used as non-invasive biomarkers for assessing endometrial receptivity status. We profiled the miRNA expression levels of 111 blood samples using next-generation sequencing to establish a predictive model for the assessment of endometrial receptivity status. This model was validated with an independent dataset (n = 73). The overall accuracy is 95.9%. Specifically, we achieved accuracies of 95.9%, 95.9%, and 100.0% for the pre-receptive group, the receptive group, and the post-respective group, respectively. Additionally, we identified a set of differentially expressed miRNAs between different endometrial receptivity statuses using the following criteria: p-value < 0.05 and fold change greater than 1.5 or less than −1.5. In conclusion, the expression levels of cell-free miRNAs in blood samples can be utilized in a non-invasive manner to distinguish different endometrial receptivity statuses.

Abstract Extensive studies concluded that homophilic interactions between pre- and postsynaptic teneurins, evolutionarily conserved cell-adhesion molecules, encode the specificity of synaptic connections. However, no direct evidence is available to demonstrate that teneurins are actually required on both pre- and postsynaptic neurons for establishing synaptic connections, nor is it known whether teneurins are localized to synapses. Using super-resolution microscopy, we demonstrate that Teneurin-3 assembles into presynaptic nanoclusters of approximately 80 nm in most excitatory synapses of the hippocampus. Presynaptic deletions of Teneurin-3 and Teneurin-4 in the medial entorhinal cortex revealed that they are required for assembly of entorhinal cortex-CA1, entorhinal cortex-subiculum, and entorhinal cortex-dentate gyrus synapses. Postsynaptic deletions of teneurins in the CA1 region, however, had no effect on synaptic connections from any presynaptic input. Our data suggest that different from the current prevailing view, teneurins promote the establishment of synaptic connections exclusively as presynaptic cell-adhesion molecules, most likely via their nanomolar-affinity binding to postsynaptic latrophilins.

Abstract The fuzzing test is able to discover various vulnerabilities and has more chances to hit the zero-day targets. And ICS(Industrial control system) is currently facing huge security threats and requires security standards, like ISO 62443, to ensure the quality of the device. However, some industrial proprietary communication protocols can be customized and have complicated structures, the fuzzing system cannot quickly generate test data that adapt to various protocols. It also struggles to define the mutation field without having prior knowledge of the protocols. Therefore, we propose a fuzzing system named ICPFuzzer that uses LSTM(Long short-term memory) to learn the features of a protocol and generates mutated test data automatically. We also use the responses of testing and adjust the weight strategies to further test the device under testing (DUT) to find more data that cause unusual connection status. We verified the effectiveness of the approach by comparing with the open-source and commercial fuzzers. Furthermore, in a real case, we experimented with the DLMS/COSEM for a smart meter and found that the test data can cause a unusual response. In summary, ICPFuzzer is a black-box fuzzing system that can automatically execute the testing process and reveal vulnerabilities that interrupt and crash industrial control communication. Not only improves the quality of ICS but also improves safety.

Artificial Intelligence (AI) is increasingly popular, and educators are paying increasing attention to it. For students, learning AI helps them better cope with emerging societal, technological, and environmental challenges. This theory of planned behavior (TPB)-based study developed a survey questionnaire to measure behavioral intention to learn AI (n = 682) among primary school students. The questionnaire was administered online, and it measured responses to five TPB factors. The five factors were (1) self-efficacy in learning AI, (2) AI readiness, (3) perceptions of the use of AI for social good, (4) AI literacy, and (5) behavioral intention. Exploratory factor analysis and a subsequent confirmatory factor analysis were used to validate this five-factor survey. Both analyses indicated satisfactory construct validity. A structural equation model (SEM) was constructed to elucidate the factors’ influence on intention to learn AI. According to the SEM, all factors could predict intention to learn AI, whether directly or indirectly. This study provides new insights for researchers and instructors who are promoting AI education in schools.

Phosphoproteomics can provide systematic insights into disease-associated cell signaling changes. Here, the authors present a sensitive workflow integrating library-based and direct data-independent acquisition approaches, and a hybrid spectral library resource for in-depth phosphoproteomic profiling.

Engineering design is a core activity in integrated science, technology, engineering, and mathematics (STEM) education. During the design process, teachers should possess interdisciplinary communication capacities to collaborate with their peers who are teaching different subjects and have epistemic fluency to comprehend multiple ways of subject matter knowing for the collective design of high-quality integrated STEM (iSTEM) lessons. This is especially so for the online mode of instruction during and after the pandemic. Teachers’ efficacies for interdisciplinary communication and epistemic fluency have rarely been explored. In this study, we aimed to examine primary school, junior high school, and high school STEM teachers’ (N = 483) efficacies for daily instruction, student engagement, interdisciplinary communication, epistemic fluency, and technological pedagogical engineering knowledge (TPEK) and designing integrated STEM instruction. An exploratory factor analysis (EFA) (n = 155) and a subsequent confirmatory factor analysis (CFA) (n = 328) were used to validate the measurement and structural model. Next, a structural equation model (SEM) was employed to examine whether these variables were reliable predictors of teachers’ integrated STEM instruction. The survey was validated with good reliabilities and the structural equation modeling supported most of the hypotheses. Statistically, the results also showed that teachers’ general efficacies for daily teaching and students’ engagement predicted their interdisciplinary communication, epistemic fluency, and TPEK. Teachers’ interdisciplinary communication predicted their epistemic fluency, TPEK, and iSTEM. Teachers’ epistemic fluency also predicted their TPEK and iSTEM. In addition, multi-group analyses were used to test the measurement invariance of the scale and to compare the latent means between the genders and subject matters. The results of the various analyses confirmed that the measurement model appeared to be equivalent across the genders and subject matters examined. Genders and subject matters did not significantly differ in any of the measured variables. The results from this study indicate that teachers’ epistemic fluency and interdisciplinary communication play essential roles in advancing their TPEK and iSTEM. Hence, this study suggests that teacher professional development should focus on enhancing teacher epistemic fluency through interdisciplinary collaboration to support the development of TPEK and iSTEM instruction.

Abnormal CSF accumulation in the brain can lead to hydrocephalus. The mechanisms regulating CSF clearance during early development are unclear. Here, the authors show that NKCC1 regulates the clearance of both CSF K+ and fluid volume through the choroid plexus during postnatal development in mice.

This study proposes and tests a theoretical model of how perceptions of disposition, engagement, and efficacy of teachers for science, technology, engineering, and mathematics (STEM) e-learning can predict their sense of vitality when they designed STEM education. Upon the proposition, we developed and validated an instrument for examining the relationships between these variables. The participants were 122 secondary teachers of STEM education from Hong Kong. The instrument included four design aspects as follows: (i) disposition, (ii) lesson design engagement, (iii) efficacy for designing STEM e-learning, and (iv) vitality of teachers after attending a series of STEM professional development activities. To analyze the relationships among the variables, partial least squares structural equation modeling was employed. The disposition of teachers predicted lesson design engagement and both of these factors, in turn, predicted efficacy for designing STEM e-learning. In other words, if teachers have a high proposition toward designing learning activities, their engagement in the lesson design process may enhance their capacities in designing and implementing such activities. Also, the disposition of teachers and lesson design engagement predicted their vitality, revealing that well-suited STEM teachers should not only be able to design a STEM curriculum but also have a positive perception of STEM education.

Abstract Background Galloway-Mowat syndrome (GAMOS) is a rare autosomal recessive disease characterized by the combination of glomerulopathy with early-onset nephrotic syndrome and microcephaly with central nervous system anomalies. Given its clinical heterogeneity, GAMOS is believed to be a genetically heterogenous group of disorders. Recently, it has been reported that mutations in KEOPS-encoding genes, including the OSGEP gene, were responsible for GAMOS. Results Overall, 6 patients from 5 different Taiwanese families were included in our study; the patients had an identical OSGEP gene mutation (c.740G > A transition) and all exhibited a uniform clinical phenotype with early-onset nephrotic syndrome, craniofacial and skeletal dysmorphism, primary microcephaly with pachygyria, and death before 2 years of age. We reviewed their clinical manifestations, the prenatal and postnatal presentations and ultrasound findings, results of imaging studies, associated anomalies, and outcome on follow-up. All individuals were found to have an “aged face” comprising peculiar facial dysmorphisms. Arachnodactyly or camptodactyly were noted in all patients. Neurological findings consisted of microcephaly, hypotonia, developmental delay, and seizures. Brain imaging studies all showed pachygyria and hypomyelination. All patients developed early-onset nephrotic syndrome. The proteinuria was steroid-resistant and eventually resulted in renal function impairment. Prenatal ultrasound findings included microcephaly, intrauterine growth restriction, and oligohydramnios. Fetal MRI in 2 patients confirmed the gyral and myelin abnormalities. Conclusions Our study suggests that a careful review of the facial features can provide useful clues for an early and accurate diagnosis. Prenatal ultrasound findings, fetal MRI, genetic counseling, and mutation analysis may be useful for an early prenatal diagnosis.

Research on self-determination theory emphasizes the importance of the internalization of motivation as a crucial factor for determining the quality of motivation. Hence, intrinsic motivation is deemed as an important predictor of learning. Research on epistemic beliefs, on the other hand, focuses on the nature of knowledge, and learning with more sophisticated epistemic beliefs associated with more adaptive outcomes. While learning and achievement are multiply determined, a more comprehensive theoretical model that takes into account both motivational quality and epistemic beliefs is needed. Hence, this study aims to examine the role of intrinsic and instrumental motivation alongside epistemic beliefs in predicting students’ achievement in science. Data were drawn from the PISA 2015 survey. We focused on four of the top-performing societies. Two were Eastern societies – Singapore and Hong Kong, and the other two were Western societies: Canada and Finland. We found both common and specific patterns among the four societies. Regarding the common patterns, we found that intrinsic motivation and epistemic beliefs had direct positive effects on science achievement. As for the regionally-specific findings, instrumental motivation positively predicted achievement only in Western societies (i.e., Finland and Canada), but not in Eastern societies (i.e., Singapore and Hong Kong). The interaction effect between motivation and epistemic beliefs also demonstrated different patterns across the four societies. Implications for the role of motivation and epistemic beliefs in optimizing student learning and achievement are discussed.

The recent advances in artificial intelligence (AI) present both challenges and opportunities for educational practitioners. A new AI curriculum has been developed and piloted in many primary schools in Beijing, China. The present study had two aims: (1) to test the factor structure of students’ motivation to learn AI and (2) to examine possible gender differences in students’ motivation to learn AI. This online questionnaire–based research recruited 420 primary students from the piloting schools. Structural equation modeling was employed to test a hypothesized model comprising six motivational factors and strategies: (1) intrinsic motivation, (2) career motivation, (3) attention, (4) relevance, (5) confidence, and (6) satisfaction. The study discovered intrinsic motivation to have the strongest influence on career motivation, while the motivational strategies of attention, relevance, and confidence also influenced career motivation. Additionally, compared with female students, male students scored higher in terms of motivational factors and strategies. The findings serve as a reference for the future development of AI curricula and instruction.

Infant hydrocephalus poses a severe global health burden; 80% of cases occur in the developing world where patients have limited access to neurosurgical care. Surgical treatment combining endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC), first practiced at CURE Children’s Hospital of Uganda (CCHU), is as effective as standard ventriculoperitoneal shunt (VPS) placement while requiring fewer resources and less post-operative care. Although treatment focuses on controlling ventricle size, this has little association with treatment failure or long-term outcome. This study aims to monitor the progression of hydrocephalus and treatment response, and investigate the association between cerebral physiology, brain growth, and neurodevelopmental outcomes following surgery. We will enroll 300 infants admitted to CCHU for treatment. All patients will receive pre/post-operative measurements of cerebral tissue oxygenation (SO2), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen consumption (CMRO2) using frequency-domain near-infrared combined with diffuse correlation spectroscopies (FDNIRS-DCS). Infants will also receive brain imaging, to monitor tissue/ventricle volume, and neurodevelopmental assessments until two years of age. This study will provide a foundation for implementing cerebral physiological monitoring to establish evidence-based guidelines for hydrocephalus treatment. This paper outlines the protocol, clinical workflow, data management, and analysis plan of this international, multi-center trial.

Summary: Brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, tropomyosin receptor kinase B (TrkB), regulate long-term potentiation (LTP) in the hippocampus, although the sites of BDNF-TrkB receptors in this process are controversial. We used a viral-mediated approach to delete BDNF or TrkB specifically in CA1 and CA3 regions of the Schaffer collateral pathway. Deletion of BDNF in CA3 or CA1 revealed that presynaptic BDNF is involved in LTP induction, while postsynaptic BDNF contributes to LTP maintenance. Similarly, loss of presynaptic or postsynaptic TrkB receptors leads to distinct LTP deficits, with presynaptic TrkB required to maintain LTP, while postsynaptic TrkB is essential for LTP formation. In addition, loss of TrkB in CA3 significantly diminishes release probability, uncovering a role for presynaptic TrkB receptors in basal neurotransmission. Taken together, this direct comparison of presynaptic and postsynaptic BDNF-TrkB reveals insight into BDNF release and TrkB activation sites in hippocampal LTP. : Lin et al. directly compare a role for presynaptic and postsynaptic BDNF and TrkB receptors in hippocampal LTP. They find that LTP induction is mediated by anterograde BDNF-TrkB signaling, while both anterograde and retrograde BDNF-TrkB signaling persists presynaptically and postsynaptically for LTP maintenance. Keywords: BDNF, TrkB, hippocampus, synaptic plasticity, LTP, presynaptic, postsynaptic

Summary: T cells compete with malignant cells for limited nutrients within the solid tumor microenvironment. We found that effector memory CD4 T cells respond distinctly from other T cell subsets to limiting glucose and can maintain high levels of interferon-γ (IFN-γ) production in a nutrient-poor environment. Unlike naive (TN) or central memory T (TCM) cells, effector memory T (TEM) cells fail to upregulate fatty acid synthesis, oxidative phosphorylation, and reductive glutaminolysis in limiting glucose. Interference of fatty acid synthesis in naive T cells dramatically upregulates IFN-γ, while increasing exogenous lipids in media inhibits production of IFN-γ by all subsets, suggesting that relative ratio of fatty acid metabolism to glycolysis is a direct predictor of T cell effector activity. Together, these data suggest that effector memory T cells are programmed to have limited ability to synthesize and metabolize fatty acids, which allows them to maintain T cell function in nutrient-depleted microenvironments. : Ecker et al. distinguish unique metabolic and functional properties of naive and memory T cell subsets during glucose limitation. During glucose starvation, T cells begin to differentially rely on fatty acid synthesis and glutamine utilization to survive. Unexpectedly, reliance on fatty acid synthesis alters the ability to produce IFN-γ. Keywords: lipid droplets, IFN-γ, oxidative phosphorylation, reductive glutaminolysis, serum-free media, naive T cell, glycolysis, effector memory T cell, fatty acid synthesis

Lithium is widely used as a treatment for Bipolar Disorder although the molecular mechanisms that underlie its therapeutic effects are under debate. In this study, we show brain-derived neurotrophic factor (BDNF) is required for the antimanic-like effects of lithium but not the antidepressant-like effects in mice. We performed whole cell patch clamp recordings of hippocampal neurons to determine the impact of lithium on synaptic transmission that may underlie the behavioral effects. Lithium produced a significant decrease in α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated miniature excitatory postsynaptic current (mEPSC) amplitudes due to postsynaptic homeostatic plasticity that was dependent on BDNF and its receptor tropomyosin receptor kinase B (TrkB). The decrease in AMPAR function was due to reduced surface expression of GluA1 subunits through dynamin-dependent endocytosis. Collectively, these findings demonstrate a requirement for BDNF in the antimanic action of lithium and identify enhanced dynamin-dependent endocytosis of AMPARs as a potential mechanism underlying the therapeutic effects of lithium.

A series of poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAAm-co-PAA) random copolymers were synthesized through free radical copolymerization in MeOH. The incorporation of the acrylic acid units into PNIPAAm tended to enhance the glass transition temperature (Tg), due to strong intermolecular hydrogen bonding between the amide groups of PNIPAAm and the carboxyl groups of PAA, as observed using 1H nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopic analyses. The lower critical solution temperature (LCST) increased upon increasing the pH of the aqueous solution containing PNIPAAm-co-PAA because the COOH groups of the PAA segment dissociated into COO− groups, enhancing the solubility of the copolymer. In addition, high-pressure differential scanning calorimetry revealed that the LCSTs of all the aqueous solutions of the copolymers decreased upon increasing the pressure of CO2, suggesting that CO2 molecules had displaced H2O molecules around the polar CONH and COOH groups in PNIPAAm-co-PAA, thereby promoting the hydrophobicity of the copolymers in the aqueous solution. In addition, the values of Tg of a film sample increased upon treatment with supercritical CO2, implying that intermolecular interactions in the copolymer had been enhanced after such treatment.

Regulated RNA translation is critical to provide proteins needed to maintain persistent modification of synaptic strength, which underlies the molecular basis of long-term memory (LTM). Cytoplasmic polyadenylation element-binding proteins (CPEBs) are sequence-specific RNA-binding proteins and regulate translation in various tissues. All four CPEBs in vertebrates are expressed in the brain, including the hippocampal neurons, suggesting their potential roles in translation-dependent plasticity and memory. Although CPEB1 and CPEB3 have been shown to control specific kinds of hippocampus-related LTM, the role of CPEB2 and CPEB4 in learning and memory remains elusive. Thus, we generated CPEB4 knockout (KO) mice and analyzed them using several behavioral tests. No difference was found in the anxiety level, motor coordination, hippocampus-dependent learning and memory between the KO mice and their wild-type (WT) littermates. Electrophysiological recordings of multiple forms of synaptic plasticity in the Schaffer collateral pathway-CA1 neurons also showed normal responses in the KO hippocampal slices. Morphological analyses revealed that the CPEB4-lacking pyramidal neurons possessed slightly elongated dendritic spines. Unlike its related family members, CPEB1 and CPEB3, CPEB4 seems to be dispensable for hippocampus-dependent plasticity, learning and memory.