BACKGROUND: Biological rhythms denote the cyclical patterns of life activities anchored to a 24-hour cycle. Research shows that depression exhibits disturbances in biological rhythms. Yet, the relationship between these biological rhythms and concomitant anxiety symptoms is insufficiently investigated in structured clinical assessments.
METHODS: This multicenter study, carried out in four Chinese hospitals, comprehensively examined the relationship between anxiety and disruptions in biological rhythms among patients with depression. The study encompassed 218 patients diagnosed with depression and 205 matched healthy controls. The Chinese version of the Biological Rhythms Interview of Assessment in Neuropsychiatry was utilized to evaluate the participants\' biological rhythms, focusing on four dimensions: sleep, activity, social, and diet.
RESULTS: In patients with depression, there is a significant positive correlation between the severity of anxiety symptoms and the disturbances in biological rhythms. The severity of anxiety and depression, along with the quality of life, are independently associated with disruptions in biological rhythms. The mediation model reveals that anxiety symptoms mediate the relationship between depressive symptoms and biological rhythms.
CONCLUSIONS: This research highlights the role of anxiety within the spectrum of depressive disorders and the associated disturbances in biological rhythms. Our findings shed light on potential pathways towards more targeted preventive strategies and therapeutic interventions for individuals battling depression and anxiety.

CONCLUSIONS: Molecular mechanisms of biological rhythms provide opportunities to harness functional allelic diversity in core (and trait- or stress-responsive) oscillator networks to develop more climate-resilient and productive germplasm. The circadian clock senses light and temperature in day-night cycles to drive biological rhythms. The clock integrates endogenous signals and exogenous stimuli to coordinate diverse physiological processes. Advances in high-throughput non-invasive assays, use of forward- and inverse-genetic approaches, and powerful algorithms are allowing quantitation of variation and detection of genes associated with circadian dynamics. Circadian rhythms and phytohormone pathways in response to endogenous and exogenous cues have been well documented the model plant Arabidopsis. Novel allelic variation associated with circadian rhythms facilitates adaptation and range expansion, and may provide additional opportunity to tailor climate-resilient crops. The circadian phase and period can determine adaptation to environments, while the robustness in the circadian amplitude can enhance resilience to environmental changes. Circadian rhythms in plants are tightly controlled by multiple and interlocked transcriptional-translational feedback loops involving morning (CCA1, LHY), mid-day (PRR9, PRR7, PRR5), and evening (TOC1, ELF3, ELF4, LUX) genes that maintain the plant circadian clock ticking. Significant progress has been made to unravel the functions of circadian rhythms and clock genes that regulate traits, via interaction with phytohormones and trait-responsive genes, in diverse crops. Altered circadian rhythms and clock genes may contribute to hybrid vigor as shown in Arabidopsis, maize, and rice. Modifying circadian rhythms via transgenesis or genome-editing may provide additional opportunities to develop crops with better buffering capacity to environmental stresses. Models that involve clock gene‒phytohormone‒trait interactions can provide novel insights to orchestrate circadian rhythms and modulate clock genes to facilitate breeding of all season crops.

BACKGROUND: Self-harm, a severe mental health concern among children and adolescents, has varying global prevalence rates. Previous studies have suggested potential associations between specific behavioral aspects of biological rhythm and self-harm risk in these populations.
OBJECTIVE: Our study aimed to elucidate the relationship between biological rhythm patterns and the propensity of self-harm among Chinese children and adolescents using the Baoxing Youth Mental Health (BYMH) cohort.
METHODS: We included 1883 Chinese children and adolescents from the BYMH cohort. The self-report questions used to assess biological rhythm and self-harm. We applied Principal Component Analysis (PCA) to distinguish patterns of biological rhythms. Logistic regression models were conducted to estimate the associations between biological rhythm, as well as biological rhythm patterns and risk of self-harm.
RESULTS: Of the participants, 35.0% reported experiencing lifetime self-harm. PCA revealed six significantly predominant biological rhythm patterns. Elevated risks of self-harm were linked with unhealthy eating practices, daytime tiredness, and unhealthy bedtime snacking. Conversely, patterns emphasizing physical exercise, family meals for breakfast, and nutritious diet exhibited decreased self-harm propensities. These trends persisted across varied self-harm attributes, including type, recency, and frequency of self-harm.
CONCLUSIONS: This study underscores the critical impact of biological rhythms on self-harm risks among Chinese youth. Targeted lifestyle interventions, focusing on improved sleep and dietary habits, could serve as potent preventive measures. Our findings lay the groundwork for future longitudinal studies to further probe these associations, fostering the creation of tailored interventions to curb self-harm and enhance mental well-being in younger populations.

Bipolar disorder (BD), a disabling mental disorder, is featured by the oscillation between episodes of depression and mania, along with disturbance in the biological rhythms. It is on an urgent demand to identify the intricate mechanisms of BD pathophysiology. Based on the continuous progression of neural science techniques, the dysfunction of circuits in the central nervous system was currently thought to be tightly associated with BD development. Yet, challenge exists since it depends on techniques that can manipulate spatiotemporal dynamics of neuron activity. Notably, the emergence of optogenetics has empowered researchers with precise timing and local manipulation, providing a possible approach for deciphering the pathological underpinnings of mental disorders. Although the application of optogenetics in BD research remains preliminary due to the scarcity of valid animal models, this technique will advance the psychiatric research at neural circuit level. In this review, we summarized the crucial aberrant brain activity and function pertaining to emotion and rhythm abnormities, thereby elucidating the underlying neural substrates of BD, and highlighted the importance of optogenetics in the pursuit of BD research.

Cancer metabolic reprogramming is a promising target for cancer therapy. The progression of tumors, including their growth, development, metastasis, and spread, is a dynamic process that varies over time and location. This means that the metabolic state of tumors also fluctuates. A recent study found that energy production efficiency is lower in solid tumors but increases significantly in tumor metastasis. Despite its importance for targeted tumor metabolism therapy, few studies have described the dynamic metabolic changes of tumors. In this commentary, we discuss the limitations of past targeted tumor metabolism therapy and the key findings of this study. We also summarize its immediate clinical implications for dietary intervention and explore future research directions for understanding the dynamic changes in tumor metabolic reprogramming.

Shifts in plant phenology regulate ecosystem structure and function, which feeds back to the climate system. However, drivers for the peak of growing season (POS) in seasonal dynamics of terrestrial ecosystems remain unclear. Here, spatial-temporal patterns of POS dynamics were analyzed by solar-induced chlorophyll fluorescence (SIF) and vegetation index in the Northern Hemisphere over the past two decades from 2001 to 2020. Overall, a slow advanced POS was observed in the Northern Hemisphere, while a delayed POS distributed mainly in northeastern North America. Trends of POS were driven by the start of growing season (SOS) rather than pre-POS climate both at hemisphere and biome scale. The effect of SOS on the trends in POS was the strongest in shrublands while the weakest in evergreen broad-leaved forest. These findings highlight the crucial role of biological rhythms rather than climatic factors in exploring seasonal carbon dynamics and global carbon balance.

Melatonin is an important endogenous hormone that modulates homeostasis in the microenvironment. Recent studies have indicated that serum melatonin levels are closely associated with the occurrence and development of osteoporosis in postmenopausal women. Exogenous melatonin could also improve bone mass and increase skeletal strength. To determine the underlying mechanisms of melatonin in the prevention and treatment of postmenopausal osteoporosis, we performed this review to analyze the role of melatonin in bone metabolism according to its physiological functions. Serum melatonin is related to bone mass, the measurement of which is a potential method for the diagnosis of osteoporosis. Melatonin has a direct effect on bone remodeling by promoting osteogenesis and suppressing osteoclastogenesis. Melatonin also regulates the biological rhythm of bone tissue, which benefits its osteogenic effect. Additionally, melatonin participates in the modulation of the bone microenvironment. Melatonin attenuates the damage induced by oxidative stress and inflammation on osteoblasts and prevents osteolysis from reactive oxygen species and inflammatory factors. As an alternative drug for osteoporosis, melatonin can improve the gut ecology, remodel microbiota composition, regulate substance absorption and maintain metabolic balance, all of which are beneficial to the health of bone structure. In conclusion, our review systematically demonstrates the effects of melatonin on bone metabolism. Based on the evidence in this review, melatonin will play a more important role in the diagnosis, prevention and treatment of postmenopausal osteoporosis.

While experimental and theoretical studies have established the prevalence of rhythmic behaviour at all levels of biological organization, less common is the coexistence between multiple oscillatory regimes (multi-rhythmicity), which has been predicted by a variety of models for biological oscillators. The phenomenon of multi-rhythmicity involves, most commonly, the coexistence between two (birhythmicity) or three (trirhythmicity) distinct regimes of self-sustained oscillations. Birhythmicity has been observed experimentally in a few chemical reactions and in biological examples pertaining to cardiac cell physiology, neurobiology, human voice patterns and ecology. The present study consists of two parts. We first review the mechanisms underlying multi-rhythmicity in models for biochemical and cellular oscillations in which the phenomenon was investigated over the years. In the second part, we focus on the coupling of the cell cycle and the circadian clock and show how an additional source of multi-rhythmicity arises from the bidirectional coupling of these two cellular oscillators. Upon bidirectional coupling, the two oscillatory networks generally synchronize in a unique manner characterized by a single, common period. In some conditions, however, the two oscillators may synchronize in two or three different ways characterized by distinct waveforms and periods. We refer to this type of multi-rhythmicity as \'multi-synchronization\'.

BACKGROUND: Iron supplements are limited by their poor absorption and low efficacy. A circadian feeding schedule would affect the circadian rhythm and improve nutrient metabolism. In this study, 18 iron-deficient piglets were randomly assigned to three groups: a control group receiving a constant diet with mid-iron (MI), a \'HL\' group receiving a high-iron (HI) diet at 8:00 h and a low-iron (LI) diet at 18:00, and an \'LH\' group receiving a LI diet at 8:00 and a HI diet at 18:00. The effects of circadian iron administration on iron absorption, iron status, and biological rhythm in iron-deficient piglets were investigated.
RESULTS: Serum iron and hemoglobin improved significantly (P < 0.05) but did not significantly differ in the circadian iron-feeding groups (P > 0.05). Iron concentration in the liver and spleen was significantly higher in the LH group than in the HL group (P < 0.05), and mRNA expression of divalent metal transport 1 (DMT1), cytochrome B (CYBRD1) and ferroportin (FPN) genes in the duodenum was significantly elevated in the LH group (P < 0.05). The clock-related genes showed differential expression in the duodenum, with greater mRNA expression for period (Per2) and cryptochrome (Cry1 and Cry2) in the LH group (P < 0.05).
CONCLUSIONS: Circadian iron administration affected iron absorption and iron storage in pigs. Iron supplementation in the evening might be a more effective pattern for iron utilization. The rhythmic system in the intestine, driven by the time, played an important role in this process. © 2020 Society of Chemical Industry.

The website and database https://snengs.nichd.nih.gov provides RNA sequencing data from multi-species analysis of the pineal glands from zebrafish (Danio rerio), chicken (White Leghorn), rat (Rattus novegicus), mouse (Mus musculus), rhesus macaque (Macaca mulatta), and human (Homo sapiens); in most cases, retinal data are also included along with results of the analysis of a mixture of RNA from tissues. Studies cover day and night conditions; in addition, a time series over multiple hours, a developmental time series and pharmacological experiments on rats are included. The data have been uniformly re-processed using the latest methods and assemblies to allow for comparisons between experiments and to reduce processing differences. The website presents search functionality, graphical representations, Excel tables, and track hubs of all data for detailed visualization in the UCSC Genome Browser. As more data are collected from investigators and improved genomes become available in the future, the website will be updated. This database is in the public domain and elements can be reproduced by citing the URL and this report. This effort makes the results of 21st century transcriptome profiling widely available in a user-friendly format that is expected to broadly influence pineal research.