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Societal Impact Statement Long‐term phenology data is crucial to elucidate the effects of climate change on plants, but such efforts are lacking in the tropics. Historical records at the Singapore Botanic Gardens and ongoing phenological monitoring have allowed us to study leafing behaviour and its association with changing rainfall patterns over nine decades in equatorial Singapore. We found that the leafing behaviour of trees in our tropical site changed between 1927 and 2022. This study was made possible by assiduous past and present record‐keeping, and demonstrates the potential of botanical gardens as sentinels of environmental change, which is especially important in the tropics. Summary Understanding tropical phenology and the potential impacts of a changing climate requires long‐term monitoring but such efforts are rare in the tropics. We took advantage of the availability of historical phenological and weather records at the Singapore Botanic Gardens and ongoing phenological monitoring to ask whether leafing behaviour has changed over an exceptionally long period of about nine decades, and whether these changes are associated with changing rainfall patterns in supposedly aseasonal Singapore. Records of leaf flush intervals from 1927 to 1939 in the Singapore Botanic Gardens were compared against leaf flush intervals calculated from present‐day phenological monitoring conducted since 2016. Daily rainfall was modelled as a predictor of present‐day leaf flushing events using moving‐window analyses. Leaf flush intervals have shortened considerably for most of the species that were monitored in the two periods. Mean daily rainfall over a window of 1 to 4 months before was negatively associated with probability of leaf flushing for five species and positively associated with four out of a total of 23 species analysed. Long‐term rainfall records from 1929 to 2022 show that February has become drier and May has become wetter since the 1960s. The results consistently support that more distinctive dry and wet periods today compared to nine decades ago have resulted in more frequent leaf flushing, which may have implications for plant‐herbivore interactions, nutrient cycling and consequently plant health and ecosystem resilience. We also demonstrate the potential and importance of supporting long‐term research in botanical gardens in the tropics.

Abstract Peritoneal metastasis (PM), the regional progression of intra-abdominal malignancies, is a common sequelae of colorectal cancer (CRC). Immunotherapy is slated to be effective in generating long-lasting anti-tumour response as it utilizes the specificity and memory of the immune system. In the tumour microenvironment, tumour associated macrophages (TAMs) are posited to create an anti-inflammatory pro-tumorigenic environment. In this paper, we aimed to identify immunomodulatory factors associated with colorectal PM (CPM). A publicly available colorectal single cell database (GSE183916) was analysed to identify possible immunological markers that are associated with the activation of macrophages in cancers. Immunohistochemical analysis for V-set and immunoglobin containing domain 4 (VSIG4) expression was performed on tumour microarrays (TMAs) of tumours of colorectal origin (n = 211). Expression of VSIG4 in cell-free ascites obtained from CPM patients (n = 39) was determined using enzyme-linked immunosorbent assay (ELISA). CD163-positive TAMs cluster expression was extracted from a publicly available single cell database and evaluated for the top 100 genes. From these macrophage-expressed genes, VSIG4, a membrane protein produced by the M2 macrophages, mediates the up-regulation of anti-inflammatory and down-regulation of pro-inflammatory macrophages, contributing to an overall anti-inflammatory state. CRC TMA IHC staining showed that low expression of VSIG4 in stromal tissues of primary CRC are associated with poor prognosis (p = 0.0226). CPM ascites also contained varying concentrations of VSIG4, which points to a possible role of VSIG4 in the ascites. The contribution of VSIG4 to CPM development can be further evaluated for its potential as an immunotherapeutic agent.

Societal Impact Statement Cities present a unique challenge for conservation. While overall native biodiversity is reduced, remnant habitats in the urban matrix can be important refugia for native and endemic species. This study reviews the rediscovery of 173 presumed nationally extinct plant taxa and discovery of 155 new native plant records, including 22 new to science and five endemics, in the botanically densely‐collected tropical city‐state of Singapore. The findings of this study indicate that plant rediscoveries and new discoveries are still possible in cities and urban areas with remaining fragments of original forest reserved for species protection, and investment in comprehensive botanical surveys and taxonomic research. Summary The conservation of native species‐dominated forest fragments and investment into botanical surveys and taxonomic research have enabled the rediscovery of presumed nationally extinct plant taxa and discovery of new native plant records in the tropical city‐state of Singapore. We compared national plant checklists of 2009, 2022, and the national Red Data Book (third edition in press) to enumerate rediscovered and newly discovered native vascular plant taxa in the last 14 years. We examined if these were from taxonomic specialist redetermination of only pre‐existing specimens or newly collected from field surveys, and if they were from particular sites and vegetation types, disproportionately represented by certain life forms and families, and predominantly threatened. We documented 173 rediscoveries and 155 new records after 2009, including 22 new to science and five endemics. Most rediscoveries were newly collected from field surveys, but most new records resulted from redetermination of pre‐existing specimens. Native species‐dominated forest fragments were the most important sites for the first collection of new records or first re‐collection of rediscoveries. Trees and climbers were well‐represented among the rediscoveries and new records. Epiphytes were significantly under‐represented compared to their proportion in the presumed nationally extinct flora. Most rediscoveries and new records are nationally Critically Endangered but regionally and globally not assessed. Our findings indicate hope for the persistence of rare native plant species and opportunities for conservation in cities.

Abstract C-oligosaccharides are found in natural products and drug molecules. Despite the considerable progress made during the last decades, modular and stereoselective synthesis of C-oligosaccharides continues to be challenging and underdeveloped compared to the synthesis technology of O-oligosaccharides. Herein, we design a distinct strategy for the stereoselective and efficient synthesis of C-oligosaccharides via palladium-catalyzed nondirected C1–H glycosylation/C2-alkenylation, cyanation, and alkynylation of 2-iodoglycals with glycosyl chloride donors while realizing the difunctionalization of 2-iodoglycals. The catalysis approach tolerates various functional groups, including derivatives of marketed drugs and natural products. Notably, the obtained C-oligosaccharides can be further transformed into various C-glycosides while fully conserving the stereochemistry. The results of density functional theory (DFT) calculations support oxidative addition mechanism of alkenyl-norbornyl-palladacycle (ANP) intermediate with α-mannofuranose chloride and the high stereoselectivity of glycosylation is due to steric hindrance.

Oxygen has long been considered as a detrimental impurity in pure titanium since it can severely deteriorate the ductility. Here, the authors propose a simple, yet effective strategy via grain refinement to solve this long-standing issue, while preserving its potential hardening effect.