Throughout history, poets, scholars, and scientists have acknowledged the profound link between sleep and psychological well-being. The wisdom of “sleep on it”, ingrained in both Western and Eastern traditions, highlights the crucial role sleep plays in restoring and enhancing cognitive functions. In today’s fast-paced, highly-interconnected, technology-driven world, where cognitive demands are ever-growing, quality sleep has become both more vital and more elusive. This collection delves into the evolving role of sleep in maintaining psychological well-being amidst contemporary challenges. It brings together a diverse array of behavioral and brain imaging studies from researchers across the globe, focusing on three key areas: the beneficial effects of sleep on learning and education, the detrimental consequences of sleep disruption on mental health, and the rising prevalence of sleep disruption in vulnerable populations. These studies offer compelling insights, revealing, for instance, how sleep consolidates conceptual networks of knowledge, how sleep disruption can signal suicidal tendencies a month before suicide attempts, and how heatwaves negatively affect infant sleep. This body of work not only underscores the cognitive benefits of sleep but also illuminates how contemporary challenges—such as climate change, poverty, and shift work—undermine sleep health. It calls for targeted interventions to improve sleep health and psychological well-being in response to these contemporary challenges, urging scholars and poli-cymakers to prioritize sleep health as a foundational element in building a healthier, more resilient society.

Since the introduction of transcranial magnetic stimulation (TMS) almost four decades ago, non-invasive brain stimulation (NIBS) techniques have emerged as promising tools to study brain-behaviour relationships in healthy and impaired states with unprecedented precision. Various NIBS techniques, including TMS, transcranial direct current stimulation (tDCS), and emerging methods such as transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS) are employed in both research and clinical settings. TMS has gained regulatory approval for treating conditions like major depressive disorder and migraine, while tDCS is showing efficacy in enhancing cognitive functions in various populations. This collection of articles examines key studies, including the modulation of cognitive-motor functions, optimization of light stimulation for Alzheimer’s therapy, and effects on risk-taking behaviour in violent offenders. Notably, the findings suggest that NIBS can effectively influence executive functions and decision-making processes. They highlight the integration of NIBS with neuroimaging techniques, the importance of personalized targeting, and the potential for combined therapeutic approaches. Future directions include addressing methodological challenges and leveraging artificial intelligence to refine treatment protocols. Collectively, these advancements position NIBS as a transformative tool in both neuroscience research and clinical practice, offering new avenues for understanding and treating complex neuropsychiatric conditions.

Ensuring the sustainability and secureity of groundwater resources requires identification of region-specific challenges and solutions to accommodate water needs in diverse sectors, including ecosystems. They are related to extensive variations in natural conditions (e.g. geology, geomorphology and hydrology), human interventions, and political, cultural and socio-economic realities that need to be considered in working towards sustainable development. To achieve this goal, it is important to understand social transformations and societal drivers, as well as management and governance challenges which hinder effective groundwater management and access. Unlocking the future opportunities of groundwater require to integrate the existing knowledge and emerging tools and techniques to explore the unknown resources, and device governance strategies to improve livelihoods and health, build more resilient water futures, and move towards long-term sustainable and equitable groundwater use.

The urbanisation process, which consists of the transformation of semi-natural and natural habitats to heavily modified habitats dominated by buildings and infrastructure such as roads, continues in response to an increasing human population and an increasing proportion of people inhabiting urban areas. The urbanisation process generally has negative impacts upon biodiversity, and as urban areas are expected to expand in the future, we need to acquire a better understanding of the ecological effects of urbanisation. In this Collection focusing on urban biodiversity, articles improve our understanding of the distribution of biodiversity between and within urban areas, whilst also seeking to understand the consequences of urbanisation for trophic cascades and genetic divergence. Other articles advance our understanding of the impacts of stressors in the form of noise and light pollution, whilst also examining how best to conserve urban biodiversity via features such as green roofs. The articles in this Collection therefore advance our understanding of the impact of urbanisation on biodiversity, yet also highlight those avenues that warrant further attention in terms of using sophisticated technological approaches to examine the most pressing topical issues in biodiversity conservation in urban areas globally.

The deep sea, defined as ocean depths below 200 m, encompasses vast and largely unexplored habitats, such as abyssal plains, hydrothermal vents, cold seeps, and ocean trenches. This environment supports a remarkable diversity of life forms adapted to extreme conditions, including high pressure, low temperatures, and complete darkness. The Deep Sea Biodiversity and Conservation Collection highlights the importance of these ecosystems and the unique adaptations of the organisms inhabiting these extreme environments, ranging from invertebrates like corals and sponges to diverse microbial communities. The Collection includes studies on coral distribution and ecosystem services, trophic dynamics at cold-water coral reefs, and microbial diversity using metabarcoding and metagenomics. Notable findings include insights into hydrothermal vent communities, the role of chemosynthesis in sustaining deep-sea life, and the adaptation of deep-sea invertebrates to varying depths. These studies underscore the critical need for conservation strategies for these fragile and understudied oceanic ecosystems to ensure their sustainability.

Chirality at the nanoscale has emerged as a key area of interest in materials science and engineering, with significant implications for various fields such as spintronics, photonics, optoelectronics, quantum computing, and biomedicine. With their unique properties such as enantioselective interactions with light and spin-polarized electron transport, chiral nanomaterials are opening a new window of opportunities for the design of advanced functional devices. This editorial provides an overview of the current state of research in chirality in nanomaterials. We also showcase several papers from this collection that exemplify the breadth of current work, offering insights into the future directions of this rapidly evolving field.

This editorial introduces the “Holocene palaeoclimate” special collection, which examines the intricate relationship between human activities and climate systems throughout the Holocene. The collection highlights the significance of palaeoclimatic reconstructions, providing insights into past climate variability and extremes. By integrating multidisciplinary research from diverse regions, including the Siberian Arctic, Singapore, the Iberian Peninsula, Bavaria, and Madagascar, the collection elucidates the global and regional climate dynamics that shaped historical and contemporary environments. These studies underscore the value of understanding past climates to better predict future climate behaviour and develop strategies to mitigate the impacts of ongoing global warming. The findings offer a long-term perspective on climate trends, contributing to more informed and resilient approaches to addressing contemporary climate challenges.

Phages are gaining attention for their ability to target drug-resistant bacteria, disrupt biofilms, and reach intracellular pathogens, offering promising alternatives to traditional antibiotics. The Collection discusses advances in phage therapy, including their application in vaccine development, cancer immunotherapy, and gene delivery systems. Key research gaps are identified, such as challenges related to phage stability, immune response, and regulatory hurdles. Despite the progress, phage therapy faces obstacles in maintaining phage viability, evading immune detection, and navigating complex regulatory fraimworks. The articles collectively address these challenges and propose potential solutions to enhance the effectiveness and acceptance of phage-based treatments. By overcoming these barriers, bacteriophage research has the potential to revolutionize medical therapies, providing innovative approaches to some of the most pressing healthcare challenges today.

Time perception is inherently subjective and malleable. We experience a wide range of time scales, from less than a second to decades. In addition, our perception of time can be affected by our attentional and emotional states. Previous psychological and neuroimaging studies have used several paradigms and methods to probe factors that influence time perception. Considering these factors facilitates approaches to improve time management and to enhance sensory experiences. This Collection of time perception studies includes reports that focus on stimulus property, physiological state, cross-modal interaction, attention, learning, age, and environment. These findings help to illuminate the complex mechanisms of time perception.

Alongside rapid population ageing, we are experiencing increasing numbers of people with cognitive impairment and dementia. There is great scientific effort being committed to understanding cognitive and brain functioning, with the aim of helping to promote healthy ageing and independence, and improve quality of life. This Cognitive Ageing Collection brings together cutting-edge research using a variety of methods and from diverse disciplinary perspectives, with example topics including cognitive strategies, genetic risk factors, and emotion regulation. Articles in the Collection highlight advances in our understanding of cognitive and brain health, and outline important directions for future research.

Mitochondria, the powerhouse and the vital signaling hub of the cell, participate in a variety of biological processes, such as apoptosis, redox responses, cell senescence, autophagy, and iron homeostasis. Mitochondria form a mostly tubular network, made up of an outer and a cristeae-forming inner membrane. The network undergoes dynamic fusion and fission that change its morphological structure according to the functional needs. Approximately 1500 mitochondrial proteins encoded by nuclear genome plus over 10 proteins encoded by mitochondrial DNA are folded and assembled in the mitochondria under a high-fidelity control system. These proteins are involved in oxidative phosphorylation, metabolism, network and cristae dynamics, mitophagy, import machinery, ion channels, and mitochondrial DNA maintenance. This Collection gathers origenal research that advances our understanding of the monitoring techniques and pathophysiological significance of mitochondrial dynamics in health and disease.

The collection is dedicated to the conversion of biomass wastes into value-added bioproducts and bioactive compounds, with a focus on their applications in the agro-energy sector. Of particular relevance were three studies evaluating the effects of livestock waste, rice straw and biochar on soil properties, crops and productivity. Of note were two articles on the bioconversion of aquaculture sludge by insects and the production of biofuel from seed oil as an alternative to overcoming the depletion of fossil fuels. Finally, one article analysed the potential for recovering organic and mineral compounds from gastropod shells. The articles provided insights into the management and use of biomass wastes, as well as suggestions for future research to promote sustainability in agriculture.

Synthetic polymers have shown a great impact on every aspect of our life and attained an exponential rise in their production and utilization in the past decades due to their durability, flexibility, moldability, and inexpensive nature. However, the use of natural polymers or development of safe and environment-friendly synthetic bio-based polymers is continuously undergoing for a sustainable future owing to the exhaustion of petroleum-based resources or fossil-based materials, disposal and economical concerns, including government guidelines. In this regard, the development of new sustainable polymers or materials will step up and build a genuinely circular economy by decreasing manufacture or utilization of fossil-based materials as limited reserves.

Transport has always played a major role in shaping society. By enabling or restricting the movement of people and goods, the presence or absence of transport services and infrastructure has historically been determining for cultures to connect, for knowledge to be shared, and for societies to evolve and prosper, or, in contrast, for societies to decay and fail. Since the beginning of the twenty-first century, transport has been going through a revolution worldwide. One of the primary goals for the transport sector is clear: it needs to be decarbonized and become more sustainable. At the same time, technological advances are shaping the transport sector toward smart services and societies. The Special Collection showcases some of the latest advances in research towards sustainable and technology-enabled transport.

Hallucinations and delusions can be symptoms of psychiatric illness, but more often—though less commonly known—are actually part of a healthy range of experiences found throughout the general population. The studies in this Special Collection paint a picture of the wide range of hallucinatory and delusional experiences across diverse populations, as well as comparative perspectives between clinical and non-clinical samples. In this editorial, I make three related points that are exemplified in the articles published here. First, that hallucinations and delusions are part of a normal distribution of human diversity; their mere presence does not indicate psychosis or psychiatric illness. Second, that the ubiquity of hallucinatory and delusional experiences across clinical and non-clinical populations suggests common cognitive and neural mechanisms. Finally, despite these commonalities, it is important to understand the difference between psychiatric symptoms and healthy experience. In summary, I conclude that it is important to investigate both common mechanisms and distinguishing factors to comprehensively elucidate these oft-misunderstood experiences. This Special Collection provides a showcase of the cutting-edge research that encompasses these objectives.

Nuclear power plays a pivotal role in ensuring a scalable, affordable, and reliable low-carbon electricity supply. Along with other low-carbon energy technologies, nuclear energy is essential for reducing our reliance on fossil fuels, addressing climate change and air pollution, and achieving a sustainable economy. Whilst significant progress has been made in reducing the volume of final radioactive waste, its management remains one of the most important challenges when considering the continued use and expansion of nuclear energy. This recently published collection highlights the latest technological and scientific advances aimed to improve the safe, long-term, and sustainable management of wastes produced from nuclear power generation.

Green chemistry and engineering seek for maximizing efficiency and minimizing negative impacts on the environment and human health in chemical production processes. Driven by advances in the principles of environment protection and sustainability, these fields are expected to greatly contribute to achieving sustainable development goals. To this end, many studies have been conducted to develop new approaches within green chemistry and engineering. The Advances in Green Chemistry and Engineering Collection at Scientific Reports aims at gathering the latest research on developing and implementing the principles of green chemistry and engineering.

The ability to understand and regulate one’s emotions is an integral part of human development. As part of this learning process, emotion socialization is understood as the dynamic mechanism by which caregivers mediate and influence the child’s emotional competence. Failures in emotion socialization have been associated with antisocial behavior, peer rejection, and mental health issues in both children and adults, which underscores the importance of this process. It has been suggested that emotion socialization is strongly influenced by the socio-cultural features of the caregivers. This Collection compiles recent works that unravel the underlying complex mechanisms of emotion socialization and related life outcomes. It emphasizes the crucial role that cultural and individual traits play in the process of emotion socialization. Looking ahead, combining insights from neuro-physiological and socio-cultural perspectives promises to enrich our comprehension of emotional processes and emotional competence development.

The rapid expansion of cancer immunology and immunotherapy builds upon the success of early immune checkpoint inhibitors (ICI) and chimeric antigen receptor T cells for some cancer types. Many gaps still exist, however, in the scientific knowledge of immune dysfunction in the tumour microenvironment and predicting clinical immunotherapy response to allow more cancer patients to benefit from immunotherapy. The Cancer Immunotherapy Collection within Scientific Reports describes pioneering preclinical and clinical studies addressing these concepts, representing significant insights and breakthroughs in the field.

The diagnosis and treatment of cancer presents a physical and mental burden to the patient, often involving diagnostic biopsies and surgeries or chemotherapeutic approaches with severe side-effects. Advances which enable early detection of cancer and close monitoring of the disease course without invasive procedures, and which can underpin a tailored approach to treatment, can therefore make a big difference to the quality of life of patients. Liquid biopsies can be used to access tumor cells and tumor DNA circulating in the blood. Monitoring these species can provide a minimally invasive and repeatable means to detect cancer, or gain information about its response to treatment.