PERIOD phosphorylation leads to feedback inhibition of CK1 activity to control circadian period.

PERIOD (PER) and Casein Kinase 1δ regulate circadian rhythms through a phosphoswitch that controls PER stability and repressive activity in the molecular clock. CK1δ phosphorylation of the familial advanced sleep phase (FASP) serine cluster embedded within the Casein Kinase 1 binding domain (CK1BD) of mammalian PER1/2 inhibits its activity on phosphodegrons to stabilize PER and extend circadian period. Here, we show that the phosphorylated FASP region (pFASP) of PER2 directly interacts with and inhibits CK1δ. Co-crystal structures in conjunction with molecular dynamics simulations reveal how pFASP phosphoserines dock into conserved anion binding sites near the active site of CK1δ. Limiting phosphorylation of the FASP serine cluster reduces product inhibition, decreasing PER2 stability and shortening circadian period in human cells. We found that Drosophila PER also regulates CK1δ via feedback inhibition through the phosphorylated PER-Short domain, revealing a conserved mechanism by which PER phosphorylation near the CK1BD regulates CK1 kinase activity.

Giant pyroelectricity in nanomembranes.

Pyroelectricity describes the generation of electricity by temporal temperature change in polar materials1-3. When free-standing pyroelectric materials approach the 2D crystalline limit, how pyroelectricity behaves remained largely unknown. Here, using three model pyroelectric materials whose bonding characters along the out-of-plane direction vary from van der Waals (In2Se3), quasi-van der Waals (CsBiNb2O7) to ionic/covalent (ZnO), we experimentally show the dimensionality effect on pyroelectricity and the relation between lattice dynamics and pyroelectricity. We find that, for all three materials, when the thickness of free-standing sheets becomes small, their pyroelectric coefficients increase rapidly. We show that the material with chemical bonds along the out-of-plane direction exhibits the greatest dimensionality effect. Experimental observations evidence the possible influence of changed phonon dynamics in crystals with reduced thickness on their pyroelectricity. Our findings should stimulate fundamental study on pyroelectricity in ultra-thin materials and inspire technological development for potential pyroelectric applications in thermal imaging and energy harvesting.

CLOCK and TIMELESS regulate rhythmic occupancy of the BRAHMA chromatin-remodeling protein at clock gene promoters.

Circadian clock and chromatin-remodeling complexes are tightly intertwined systems that regulate rhythmic gene expression. The circadian clock promotes rhythmic expression, timely recruitment, and/or activation of chromatin remodelers, while chromatin remodelers regulate accessibility of clock transcription factors to the DNA to influence expression of clock genes. We previously reported that the BRAHMA (BRM) chromatin-remodeling complex promotes the repression of circadian gene expression in Drosophila. In this study, we investigated the mechanisms by which the circadian clock feeds back to modulate daily BRM activity. Using chromatin immunoprecipitation, we observed rhythmic BRM binding to clock gene promoters despite constitutive BRM protein expression, suggesting that factors other than protein abundance are responsible for rhythmic BRM occupancy at clock-controlled loci. Since we previously reported that BRM interacts with two key clock proteins, CLOCK (CLK) and TIMELESS (TIM), we examined their effect on BRM occupancy to the period (per) promoter. We observed reduced BRM binding to the DNA in clk null flies, suggesting that CLK is involved in enhancing BRM occupancy to initiate transcriptional repression at the conclusion of the activation phase. Additionally, we observed reduced BRM binding to the per promoter in flies overexpressing TIM, suggesting that TIM promotes BRM removal from DNA. These conclusions are further supported by elevated BRM binding to the per promoter in flies subjected to constant light and experiments in Drosophila tissue culture in which the levels of CLK and TIM are manipulated. In summary, this study provides new insights into the reciprocal regulation between the circadian clock and the BRM chromatin-remodeling complex.

Regulation of protein O-GlcNAcylation by circadian, metabolic, and cellular signals.

O-linked ß-N-acetylglucosamine (O-GlcNAcylation) is a dynamic post-translational modification that regulates thousands of proteins and almost all cellular processes. Aberrant O-GlcNAcylation has been associated with numerous diseases, including cancer, neurodegenerative diseases, cardiovascular diseases, and type 2 diabetes. O-GlcNAcylation is highly nutrient-sensitive since it is dependent on UDP-GlcNAc, the end product of the hexosamine biosynthetic pathway (HBP). We previously observed daily rhythmicity of protein O-GlcNAcylation in a Drosophila model that is sensitive to the timing of food consumption. We showed that the circadian clock is pivotal in regulating daily O-GlcNAcylation rhythms given its control of the feeding-fasting cycle and hence nutrient availability. Interestingly, we reported that the circadian clock also modulates daily O-GlcNAcylation rhythm by regulating molecular mechanisms beyond the regulation of food consumption time. A large body of work now indicates that O-GlcNAcylation is likely a generalized cellular status effector as it responds to various cellular signals and conditions, such as ER stress, apoptosis, and infection. In this review, we summarize the metabolic regulation of protein O-GlcNAcylation through nutrient availability, HBP enzymes, and O-GlcNAc processing enzymes. We discuss the emerging roles of circadian clocks in regulating daily O-GlcNAcylation rhythm. Finally, we provide an overview of other cellular signals or conditions that impact O-GlcNAcylation. Many of these cellular pathways are themselves regulated by the clock and/or metabolism. Our review highlights the importance of maintaining optimal O-GlcNAc rhythm by restricting eating activity to the active period under physiological conditions and provides insights into potential therapeutic targets of O-GlcNAc homeostasis under pathological conditions.

Influence of static and dynamic ocular aberrations on full-field optical coherence tomography for in vivo high-resolution retinal imaging.

Under spatially incoherent illumination, time-domain full-field optical coherence tomography (FFOCT) offers the possibility to achieve in vivo retinal imaging at cellular resolution over a wide field of view. Such performance is possible, albeit there is the presence of ocular aberrations even without the use of classical adaptive optics. While the effect of aberrations in FFOCT has been debated these past years, mostly on low-order and static aberrations, we present, for the first time to our knowledge, a method enabling a quantitative study of the effect of statistically representative static and dynamic ocular aberrations on FFOCT image metrics, such as SNR, resolution, and image similarity. While we show that ocular aberrations can decrease FFOCT SNR and resolution by up to 14 dB and fivefold, we take advantage of such quantification to discuss different possible compromises between performance gain and adaptive optics complexity and speed, to optimize both sensor-based and sensorless FFOCT high-resolution retinal imaging.

Design and Fabrication of a Film Bulk Acoustic Wave Filter for 3.0 GHz-3.2 GHz S-Band.

Film bulk acoustic-wave resonators (FBARs) are widely utilized in the field of radio frequency (RF) filters due to their excellent performance, such as high operation frequency and high quality. In this paper, we present the design, fabrication, and characterization of an FBAR filter for the 3.0 GHz-3.2 GHz S-band. Using a scandium-doped aluminum nitride (Sc0.2Al0.8N) film, the filter is designed through a combined acoustic-electromagnetic simulation method, and the FBAR and filter are fabricated using an eight-step lithographic process. The measured FBAR presents an effective electromechanical coupling coefficient (keff2) value up to 13.3%, and the measured filter demonstrates a -3 dB bandwidth of 115 MHz (from 3.013 GHz to 3.128 GHz), a low insertion loss of -2.4 dB, and good out-of-band rejection of -30 dB. The measured 1 dB compression point of the fabricated filter is 30.5 dBm, and the first series resonator burns out first as the input power increases. This work paves the way for research on high-power RF filters in mobile communication.

Enhanced metal-free photocatalyst performance by synergistic Coupling of internal magnetic field and piezoelectric field.

Graphitic carbon nitride (g-C3N4) is a promising metal-free photocatalyst; however, its high carrier recombination rate and insufficient redox capacity limit its degradation effect on antibiotics. In order to overcome these shortcomings, the photocatalytic activity is improved by regulating the spin polarization state, constructing the internal electric field, and applying the external piezoelectric field. In this paper, the chlorine-doped and nitrogen-deficient porous carbon nitride composite carbon quantum dots (Nv-Cl/UPCN@CQD) has been synthesized successfully. The doping position of chlorine and spin polarization properties are verified by DFT calculation. The key intermediates *O2- and *OOH for the synthesis of reactive oxygen species were detected by in-situ infrared testing, which promotes the production of •O2- and H2O2. The degradation rate constant of Nv-Cl/UPCN@CQD for removal of tetracycline is 8.45 times higher than that of g-C3N4. The active oxygen production and degradation efficiency of piezoelectric photocatalysis under the synergistic effect of intense stirring and vis-light irradiation are much higher than those of photocatalysis and piezoelectric catalysis, and the conversion of H2O2 to •OH is promoted by piezoelectric field. This paper provides a reliable way to improve the performance of piezoelectric photocatalysts by adjusting their energy band, electronic structure and piezoelectric force.

Discrimination of blood metabolomics profiles in neonates with idiopathic polyhydramnios.

This study aimed to compare the blood metabolic status of neonates with idiopathic polyhydramnios (IPH) and those with normal amniotic fluid, and to explore the relationship between IPH and fetal health. Blood metabolites of 32 patients with IPH and 32 normal controls admitted to the Sixth Affiliated Hospital of Sun Yat-sen University between January 2017 and December 2022 were analyzed using liquid chromatography-mass spectrometry (LC-MS/MS). Orthogonal partial least squares discriminant analysis (OPLS-DA) and metabolite enrichment analyses were performed to identify the differential metabolites and metabolic pathways. There was a significant difference in the blood metabolism between newborns with IPH and those with normal amniotic fluid. Six discriminant metabolites were identified: glutamate, serine, asparagine, aspartic acid, homocysteine, and phenylalanine. Differential metabolites were mainly enriched in two pathways: aminoacyl-tRNA biosynthesis, and alanine, aspartate, and glutamate metabolism. CONCLUSIONS: This study is the first to investigate metabolomic profiles in newborns with IPH and examine the correlation between IPH and fetal health. Differential metabolites and pathways may affect amino acid synthesis and the nervous system. Continuous attention to the development of the nervous system in children with IPH is necessary. WHAT IS KNOWN: • There is an increased risk of adverse pregnancy outcomes with IPH, such as perinatal death, neonatal asphyxia, neonatal intensive care admission, cesarean section rates, and postpartum hemorrhage. • Children with a history of IPH have a higher proportion of defects than the general population, particularly central nervous system problems, neuromuscular disorders, and other malformations. WHAT IS NEW: • In neonates with IPH, six differential metabolites were identified with significant differences and good AUC values using LC-MS/MS analysis: glutamic acid, serine, asparagine, aspartic acid, homocysteine, and phenylalanine, which were mainly enriched in two metabolic pathways: aminoacyl-tRNA biosynthesis and alanine, aspartate, and glutamate metabolism. • These differential metabolites and pathways may affect amino acid synthesis and development of the nervous system in neonates with IPH.

EYES ABSENT and TIMELESS integrate photoperiodic and temperature cues to regulate seasonal physiology in Drosophila.

Organisms possess photoperiodic timing mechanisms to detect variations in day length and temperature as the seasons progress. The nature of the molecular mechanisms interpreting and signaling these environmental changes to elicit downstream neuroendocrine and physiological responses are just starting to emerge. Here, we demonstrate that, in Drosophila melanogaster, EYES ABSENT (EYA) acts as a seasonal sensor by interpreting photoperiodic and temperature changes to trigger appropriate physiological responses. We observed that tissue-specific genetic manipulation of eya expression is sufficient to disrupt the ability of flies to sense seasonal cues, thereby altering the extent of female reproductive dormancy. Specifically, we observed that EYA proteins, which peak at night in short photoperiod and accumulate at higher levels in the cold, promote reproductive dormancy in female D. melanogaster Furthermore, we provide evidence indicating that the role of EYA in photoperiodism and temperature sensing is aided by the stabilizing action of the light-sensitive circadian clock protein TIMELESS (TIM). We postulate that increased stability and level of TIM at night under short photoperiod together with the production of cold-induced and light-insensitive TIM isoforms facilitate EYA accumulation in winter conditions. This is supported by our observations that tim null mutants exhibit reduced incidence of reproductive dormancy in simulated winter conditions, while flies overexpressing tim show an increased incidence of reproductive dormancy even in long photoperiod.

[Blood metabolites in preterm infants with retinopathy of prematurity based on tandem mass spectrometry: a preliminary study]. / åŸºäºŽè´¨è°±æŠ€æœ¯çš„æ—©äº§å„¿è§†ç½‘è†œç— è¡€ä»£è°¢äº§ç‰©çš„åˆæ­¥ç ”ç©¶.

OBJECTIVES: To study new biomarkers for the early diagnosis of retinopathy of prematurity (ROP) by analyzing the differences in blood metabolites based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and metabolomics. METHODS: Dried blood spots were collected from 21 infants with ROP (ROP group) and 21 infants without ROP (non-ROP group) who were hospitalized in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2016. LC-MS/MS was used to measure the metabolites, and orthogonal partial least squares-discriminant analysis was used to search for differentially expressed metabolites and biomarkers. RESULTS: There was a significant difference in blood metabolic profiles between the ROP and non-ROP groups. The pattern recognition analysis, Score-plot, and weight analysis obtained 10 amino acids with a relatively large difference. Further statistical analysis showed that the ROP group had significant increases in blood levels of glutamic acid, leucine, aspartic acid, ornithine, and glycine compared with the non-ROP group (P<0.05). The receiver operating characteristic curve analysis showed that glutamic acid and ornithine had the highest value in diagnosing ROP. CONCLUSIONS: Blood metabolites in preterm infants with ROP are different from those without ROP. Glutamic acid and ornithine are the metabolic markers for diagnosing ROP. LC-MS/MS combined with metabolomics analysis has a potential application value in the early identification and diagnosis of ROP.

Synaptic loss in a mouse model of euthyroid Hashimoto's thyroiditis: possible involvement of the microglia.

BACKGROUND: Hashimoto's thyroiditis (HT) is an autoimmune illness that renders individuals vulnerable to neuropsychopathology even in the euthyroid state, the mechanisms involved remain unclear. We hypothesized that activated microglia might disrupt synapses, resulting in cognitive disturbance in the context of euthyroid HT, and designed the present study to test this hypothesis. METHODS: Experimental HT model was induced by immunizing NOD mice with thyroglobulin and adjuvant twice. Morris Water Maze was measured to determine mice spatial learning and memory. The synaptic parameters such as the synaptic density, synaptic ultrastructure and synaptic-markers (SYN and PSD95) as well as the interactions of microglia with synapses were also determined. RESULTS: HT mice had poorer performance in Morris Water Maze than controls. Concurrently, HT resulted in a significant reduction in synapse density and ultrastructure damage, along with decreased synaptic puncta visualized by immunostaining with synaptophysin and PSD-95. In parallel, frontal activated microglia in euthyroid HT mice showed increased engulfment of PSD95 and EM revealed that the synaptic structures were visible within the microglia. These functional alterations in microglia corresponded to structural increases in their attachment to neuronal perikarya and a reduction in presynaptic terminals covering the neurons. CONCLUSION: Our results provide initial evidence that HT can induce synaptic loss in the euthyroid state with deficits might be attributable to activated microglia, which may underlie the deleterious effects of HT on spatial learning and memory.

Ca2+ transfer via the ER-mitochondria tethering complex in neuronal cells contribute to cadmium-induced autophagy.

Mitochondrial-associated endoplasmic reticulum (ER) membranes (MAMs) play a key role in several physiological functions, including calcium ion (Ca2+) transfer and autophagy; however, the molecular mechanism controlling this interaction in cadmium (Cd)-induced neurotoxicity is unknown. This study shows that Cd induces alterations in MAMs and mitochondrial Ca2+ levels in PC12 cells and primary neurons. Ablation or silencing of mitofusin 2 (Mfn2) in PC12 cells or primary neurons blocks the colocalization of ER and mitochondria while reducing the efficiency of mitochondrial Ca2+ uptake. Moreover, Mfn2 defects reduce interactions or colocalization between GRP75 and VDAC1. Interestingly, the enhancement of autophagic protein levels, colocalization of LC3 and Lamp2, and GFP-LC3 puncta induced by Cd decreased in Mfn2-/- or Grp75-/- PC12 cells and Mfn2- or Grp75-silenced primary neurons. Notably, the specific Ca2+ uniporter inhibitor RuR blocked both mitochondrial Ca2+ uptake and autophagy induced by Cd. Finally, this study proves that the mechanism by which IP3R-Grp75-VDAC1 tethers in MAMs is associated with the regulation of autophagy by Mfn2 and involves their role in mediating mitochondrial Ca2+ uptake from ER stores. These results give new evidence into the organelle metabolic process by demonstrating that Ca2+ transport between ER-mitochondria is important in autophagosome formation in Cd-induced neurodegeneration.

Rational design of minimal synthetic promoters for plants.

Promoters serve a critical role in establishing baseline transcriptional capacity through the recruitment of proteins, including transcription factors. Previously, a paucity of data for cis-regulatory elements in plants meant that it was challenging to determine which sequence elements in plant promoter sequences contributed to transcriptional function. In this study, we have identified functional elements in the promoters of plant genes and plant pathogens that utilize plant transcriptional machinery for gene expression. We have established a quantitative experimental system to investigate transcriptional function, investigating how identity, density and position contribute to regulatory function. We then identified permissive architectures for minimal synthetic plant promoters enabling the computational design of a suite of synthetic promoters of different strengths. These have been used to regulate the relative expression of output genes in simple genetic devices.

Splice variants of DOMINO control Drosophila circadian behavior and pacemaker neuron maintenance.

Circadian clocks control daily rhythms in behavior and physiology. In Drosophila, the small ventral lateral neurons (sLNvs) expressing PIGMENT DISPERSING FACTOR (PDF) are the master pacemaker neurons generating locomotor rhythms. Despite the importance of sLNvs and PDF in circadian behavior, little is known about factors that control sLNvs maintenance and PDF accumulation. Here, we identify the Drosophila SWI2/SNF2 protein DOMINO (DOM) as a key regulator of circadian behavior. Depletion of DOM in circadian neurons eliminates morning anticipatory activity under light dark cycle and impairs behavioral rhythmicity in constant darkness. Interestingly, the two major splice variants of DOM, DOM-A and DOM-B have distinct circadian functions. DOM-A depletion mainly leads to arrhythmic behavior, while DOM-B knockdown lengthens circadian period without affecting the circadian rhythmicity. Both DOM-A and DOM-B bind to the promoter regions of key pacemaker genes period and timeless, and regulate their protein expression. However, we identify that only DOM-A is required for the maintenance of sLNvs and transcription of pdf. Lastly, constitutive activation of PDF-receptor signaling rescued the arrhythmia and period lengthening of DOM downregulation. Taken together, our findings reveal that two splice variants of DOM play distinct roles in circadian rhythms through regulating abundance of pacemaker proteins and sLNvs maintenance.

Pressure-induced semiconductor-to-metal phase transition of a charge-ordered indium halide perovskite.

Phase transitions in halide perovskites triggered by external stimuli generate significantly different material properties, providing a great opportunity for broad applications. Here, we demonstrate an In-based, charge-ordered (In+/In3+) inorganic halide perovskite with the composition of Cs2In(I)In(III)Cl6 in which a pressure-driven semiconductor-to-metal phase transition exists. The single crystals, synthesized via a solid-state reaction method, crystallize in a distorted perovskite structure with space group I4/m with a = 17.2604(12) Å, c = 11.0113(16) Å if both the strong reflections and superstructures are considered. The supercell was further confirmed by rotation electron diffraction measurement. The pressure-induced semiconductor-to-metal phase transition was demonstrated by high-pressure Raman and absorbance spectroscopies and was consistent with theoretical modeling. This type of charge-ordered inorganic halide perovskite with a pressure-induced semiconductor-to-metal phase transition may inspire a range of potential applications.

A High-Sensitivity Gravimetric Biosensor Based on S1 Mode Lamb Wave Resonator.

The development of MEMS acoustic resonators meets the increasing demand for in situ detection with a higher performance and smaller size. In this paper, a lithium niobate film-based S1 mode Lamb wave resonator (HF-LWR) for high-sensitivity gravimetric biosensing is proposed. The fabricated resonators, based on a 400-nm X-cut lithium niobate film, showed a resonance frequency over 8 GHz. Moreover, a PMMA layer was used as the mass-sensing layer, to study the performance of the biosensors based on HF-LWRs. Through optimizing the thickness of the lithium niobate film and the electrode configuration, the mass sensitivity of the biosensor could reach up to 74,000 Hz/(ng/cm2), and the maximum value of figure of merit (FOM) was 5.52 × 107, which shows great potential for pushing the performance boundaries of gravimetric-sensitive acoustic biosensors.

Plcz1 Deficiency Decreased Fertility in Male Mice Which Is Associated with Sperm Quality Decline and Abnormal Cytoskeleton in Epididymis.

Phospholipase C zeta1 (Plcz1) was known to be a physiological factor in sperm that activates oocytes to complete meiosis by triggering Ca2+ oscillations after fertilisation. However, the role of male Plcz1 in spermatogenesis and early embryo development in progeny has been controversial. Plcz1 knockout (Plcz1-/-) mouse model (Plcz1m3 and Plcz1m5) was generated by using the CRISPR-Cas9 system. The fertility of Plcz1-/- mice was evaluated by analysing the number of offsprings, sperm quality, pathological changes in the testis and epididymis. RNA-seq and RT-PCR were performed to screen differentially expressed genes and signalling pathways related to fertility in Plcz1-/- mice. Further mechanism was explored by using Plcz1-/- cells. Plcz1 knockout led to hypofertility in male mice. In particular, a significant time delay in development and polyspermy was found in eggs fertilized by both Plcz1m3 and Plcz1m5 sperm. Interestingly, a decline in sperm quality combined with pathological changes in epididymis was found in Plcz1m3 mice but not in Plcz1m5 mice. Notably, abnormal cytoskeleton appears in epididymis of Plcz1m3 mice and Plcz1-/- cells. Cytoskeleton damage of epididymis is involved in fertility decline of males upon Plcz1 deficiency in this model.

A Novel Tri-Axial Piezoelectric MEMS Accelerometer with Folded Beams.

Microelectromechanical (MEMS) piezoelectric accelerometers are diversely used in consumer electronics and handheld devices due to their low power consumption as well as simple reading circuit and good dynamic performance. In this paper, a tri-axial piezoelectric accelerometer with folded beams is presented. The four beam suspensions are located at two sides of the mass aligned with edges of the mass, and the thickness of the beams is the same as the thickness of the mass block. In order to realize the multi-axis detection, a total of 16 sensing elements are distributed at the end of the folded beams. The structural deformations, stress distribution, and output characteristics due to the acceleration in x-, y-, and z-axis directions are theoretically analyzed and simulated. The proposed accelerometer is fabricated by MEMS processes to form Mo/AlN/ScAlN/Mo piezoelectric stacks as the sensing layer. Experiments show that the charge sensitivity along the x-, y-, and z-axes could reach up to ~1.07 pC/g, ~0.66 pC/g, and ~3.35 pC/g. The new structure can provide inspiration for the design of tri-axial piezoelectric accelerometers with great sensitivity and linearity.

[Thoughts and Suggestions on Review of Autoimmune Test Reagents].

In this paper, some significant problems, which were found frequently in the products of autoimmune in vitro diagnostic reagents, were summarized and analyzed in detail, and meanwhile a few relevant suggestions were put forward, which should be paid attention in the process of registration and application.

[Relationship between Reference Interval Establishment and Clinical Evaluation in Quantitative in Vitro Diagnostic Reagents].

Reference interval study and clinical evaluation are crucial supportive researches to demonstrate the intended use of quantitative in vitro diagnostic reagents. The process of determining reference interval, as well as the problems found frequently in clinical evaluation, are discussed here, and the links between them are analyzed from the aspects of product's traceability, intended use and group design. Further, some suggestions are offered in this paper.