Sex disparity in the association between metabolic-anthropometric phenotypes and risk of obesity-related cancer: a prospective cohort study.

BACKGROUND: Sex disparity between metabolic-obesity (defined by body mass index, BMI) phenotypes and obesity-related cancer (ORC) remains unknown. Considering BMI reflecting overall obesity but not fat distribution, we aimed to systematically assess the association of our newly proposed metabolic-anthropometric phenotypes with risk of overall and site-specific ORC by sex. METHODS: A total of 141,579 men (mean age: 56.37 years, mean follow-up time: 12.04 years) and 131,047 women (mean age: 56.22 years, mean follow up time: 11.82 years) from the UK Biobank was included, and designated as metabolic-anthropometric phenotypes based on metabolic status (metabolically healthy/unhealthy), BMI (non-obesity/obesity) and body shape (pear/slim/apple/wide). The sex-specific association of different phenotypes with overall and site-specific ORC was assessed by hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression models. RESULTS: We found metabolically unhealthy and/or obesity phenotypes conveyed a higher risk in men than in women for overall ORC and colorectal cancer compared with metabolically healthy non-obesity phenotype (Pinteraction < 0.05). Of note, metabolically healthy obesity phenotype contributed to increased risks of most ORC in men (HRs: 1.58 ~ 2.91), but only correlated with higher risks of endometrial (HR = 1.89, 95% CI: 1.54-2.32) and postmenopausal breast cancers (HR = 1.17, 95% CI: 1.05-1.31) in women. Similarly, even under metabolically healthy, men carrying apple and wide shapes phenotypes (metabolically healthy apple/wide and metabolically healthy non-obesity apple/wide) suffered an increased risk of ORC (mainly colorectal, liver, gastric cardia, and renal cancers, HRs: 1.20 ~ 3.81) in comparison with pear shape or non-obesity pear shape. CONCLUSIONS: There was a significant sex disparity between metabolic-anthropometric phenotypes and ORC risk. We advised future ORC prevention and control worth taking body shape and sex disparity into account.

Association between walking pace and risks of major chronic diseases in individuals with hypertension based on a prospective study in UK Biobank: Involvement of inflammation.

OBJECTIVE: Walking pace is associated with risks of major chronic diseases including cancer, cardiovascular disease (CVD) and diabetes mellitus type 2 (T2DM) in the general population. However, whether increasing walking pace could reduce risks of major chronic diseases in individuals with hypertension remains to be explored, and the underlying mechanism potentially mediated by low-grade inflammation is also unclear. METHODS: A total of 160,470 participants with hypertension were included based on the UK Biobank. The relationships of the walking pace and low-grade inflammation with risks of major chronic diseases in individuals with hypertension were assessed by the Cox proportional hazards model. Mediation analyses were performed to investigate the contribution of low-grade inflammation to the association between walking pace and risks of major chronic diseases. RESULTS: Individuals with hypertension at the brisk walking pace had decreased risks of overall cancer and site-specific cancers (liver, lung, and endometrial cancers), all CVD events (angina, atrial fibrillation, heart failure, myocardial infarction, peripheral vascular disease and stroke), and T2DM (hazard ratios: 0.42-0.91). Increasing low-grade inflammation was associated with higher risks of aforementioned diseases except liver cancer and atrial fibrillation. Furthermore, low-grade inflammation partially mediated associations of the walking pace with risks of lung cancer, T2DM, and all CVD events (except atrial fibrillation), with mediation proportion of 2.0%-9.8%. CONCLUSIONS: Brisk walking pace was linked to reduced risks of major chronic diseases in individuals with hypertension, partially mediated by low-grade inflammation. Improving walking pace may be beneficial for health in individuals with hypertension.

Joint association of biological aging and lifestyle with risks of cancer incidence and mortality: A cohort study in the UK Biobank.

BACKGROUND: Aging is a risk factor for cancer incidence and mortality. Biological aging can reflect the aging degree of the body better than chronological age and can be aggravated by unhealthy lifestyle factors. We aimed to assess the joint effect of biological aging and lifestyle with risks of cancer incidence and mortality. METHODS: This study included a total of 281,889 participants aged 37 to 73 from the UK Biobank database. Biological age was derived from chronological age and 9 clinical blood indicators, and lifestyle score was constructed by body mass index, smoking status, alcohol consumption, physical activity, and diet. Multivariate Cox hazard proportional regression model was used to analyze the independent and joint association of biological aging and lifestyle with risks of cancer incidence and mortality, respectively. RESULTS: Over a median follow-up period of 12.3 years, we found that older biological age was associated with increased risks of overall cancer, digestive system cancers, lung, breast and renal cancers incidence and mortality (HRs: 1.12-2.25). In the joint analysis of biological aging and lifestyle with risks of cancer incidence and mortality, compared with unhealthy lifestyle and younger biological age, individuals with healthy lifestyle and older biological age had decreased risks of incidence (8% âˆ¼ 60%) and mortality (20% âˆ¼ 63%) for overall, esophageal, colorectal, pancreatic and lung cancers. CONCLUSIONS: Biological aging may be an important risk factor for cancer morbidity and mortality. A healthier lifestyle is more likely to mitigate the adverse effects of biological aging on overall cancer and some site-specific cancers.

Plant-based dietary patterns, genetic predisposition and risk of colorectal cancer: a prospective study from the UK Biobank.

BACKGROUND: Plant-based dietary patterns may affect colorectal cancer (CRC) related outcomes, while risks differ in the quality of plant foods. We aimed to examine the association of plant-based diet quality with risks of CRC incidence and mortality and whether this association was modified by genetic risk. METHODS: This prospective cohort study included 186,675 participants free of cancer when the last dietary recall was completed. We calculated three plant-based diet indices (PDIs), i.e., the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI) representing adherence to plant-based diets with diverse quality. Genetic risk was characterized using a weighted polygenic risk score (PRS), capturing overall risk variants associated with CRC. Hazard ratios (HR) and 95% confidential intervals (CI) were estimated by the cause-specific Cox proportional hazards model. RESULTS: Over a follow-up of 9.5 years, 2163 cases and 466 deaths from CRC were documented. The HR of CRC incidence was 0.88 (95% CI, 0.81-0.96) and 0.91 (95% CI, 0.84-0.99) per 10-score increase in PDI and hPDI, respectively. Compared to the lowest quartile, PDI, hPDI, and uPDI in the highest quartile were associated with a 13% decrease, a 15% decrease, and a 14% increase in risk of incident CRC, respectively. We found a joint association of genetic risk and PDIs with incident CRC, with the highest hazard observed in those carrying higher PRS and adhering to lower-quality PDIs. The inverse association of PDI and hPDI with CRC mortality was pronounced in males. CONCLUSIONS: Our results suggested that better adherence to overall and healthful plant-based diets was associated with a lower risk of CRC, whereas an unhealthful plant-based diet was associated with a higher CRC risk. Consumption of a higher-quality plant-based diet combined with decreased genetic risk conferred less susceptibility to CRC. Our findings highlighted the importance of food quality when adhering to a plant-based dietary pattern for CRC prevention in the general population.

Modulation of Nano-superstructures and Their Optical Properties.

Self-assembly, which enables spontaneous arrangement of objects, is of particular importance for nanomaterials in both fundamental and applied research fields. Multiple types of nanoparticle superstructures have been successfully built in highly controllable and efficient manners through balancing the nanoscale interactions. Uniform and proper arrangement of nanoparticles inside the assembled superstructures is essential to exhibit their constant, reliable, and homogeneous functionalities. To be specific, the long-range ordered superlattices not only succeed with their building blocks' intrinsic property, but also, more importantly, can display collective properties that are absent both in individual nanoparticles and in their bulk states. One of the most attractive aspects of nanomaterials is their exceptional optical properties that have tremendous application potential in multidisciplinary fields. In this regard, constructing the superstructures from optical nano units like noble metal nanostructures, semiconductor nanoparticles, or hybrid nanomaterials is critical for attaining the unique optical properties and exploring their practical applications in multiple fields including photonics, optoelectronics, optical sensing, photocatalysis, etc. In this Account, we provide guidelines for self-assembly strategies to fabricate the superstructures and discuss the optical properties that the superstructures display. In the first part, we categorize and discuss the key factors that strongly affect the self-assembly process and determine the configurational and integral quality of the superstructures. On one hand, the diversity and designability of nanoparticles offer the intrinsic complexity of the building blocks, including geometry, size, composition, and surface ligand, which efficiently tailors the assembly process and superstructure configuration. On the other hand, multiple factors originating from the introduction of extrinsic features are recognized to facilitate the metastable or dynamic self-assembly process. Such extrinsic features include both matter like DNA origami, peptides, small molecules, etc. and nonmatter involved with electric fields, magnetic fields, light, temperature, etc. In the second part, we introduce the state-of the art progress on the collective optical performances of the assembled superstructures, including (1) chiral optics, such as circular dichroism and circularly polarized luminescence, (2) plasmonic properties and related applications, and (3) luminescence related optics and their applications. Finally, we summarize the existing problems and main challenges briefly, and some future directions of this field are proposed. We envision that, with deep understanding of the assembly mechanism and development of the synthetic and surface chemistry, rational modulation of nanoassemblies will be the trend of this field, which is beneficial to achieve the emerging collective performances and create new generation devices with advanced functions.

Dietary flavonoid intake and risk of hormone-related cancers: A population-based prospective cohort study.

BACKGROUND: Dietary flavonoids may have potential effects on hormone-related cancers (HRCs) due to their anti-cancer properties via regulating hormones and suppressing inflammation and oxidative stress. We aimed to examine the association of flavonoid intake with risks of HRCs and whether this association was mediated by blood biomarkers involved in biological mechanisms. METHODS: This prospective cohort study from UK Biobank included 187,350 participants free of cancer when the last dietary recall was completed. The dietary intakes of flavonoids and subclasses were assessed using 24-hour dietary recalls. Venous blood was collected at baseline and assayed for biomarkers of inflammation, hormones, and oxidative stress. Hazard ratios (HR) and 95 % confidential intervals (CI) for the associations between flavonoid intake and HRCs risk were estimated by the cause-specific Cox proportional hazards model. The role of blood biomarkers in the flavonoids-HRCs association was investigated through mediation analysis. RESULTS: Over a median follow-up of 9.5 years, 3,392 female breast cancer, 417 ovarian cancer, 516 endometrial cancer, 4,305 prostate cancer, 45 testicular cancer, and 146 thyroid cancer cases were documented. Compared to the lowest quintile, multivariable-adjusted HRs (95 % CIs) in the highest quintile of total flavonoid intake were 0.89 (0.80-0.99) for breast cancer, 0.68 (0.50-0.92) for ovarian cancer, and 0.88 (0.80-0.98) for female-specific cancers. For subclasses, intakes of flavonols and anthocyanidins were inversely associated with the risk of female-specific cancers (Ptrend <0.05). Anthocyanidin intake was positively related to prostate cancer risk, whereas isoflavone intake was inversely linked to thyroid cancer risk (Ptrend <0.05). Additionally, certain biomarkers of inflammation, hormones and oxidative stress jointly mediated the association of flavonoid intake with the risk of female-specific cancers and prostate cancer. CONCLUSIONS: Our findings highlighted the importance of dietary flavonoids for the prevention of HRCs in the general population, providing epidemiological evidence for dietary guidelines.

Cardiovascular health, polygenic risk score, and cancer risk: a prospective cohort study.

BACKGROUND: Cancer and cardiovascular disease share common lifestyle risk factors. However, it remains unclear whether cardiovascular health (CVH) evaluated by Life's Essential 8 can predict cancer risk, and attenuate the influence of genetic susceptibility on cancer. OBJECTIVES: We aimed to evaluate independent and joint associations of CVH and polygenic risk score (PRS) with risks of overall and site-specific cancers. METHODS: We undertook a population-based cohort study based on the UK Biobank. The CVH score was constructed by physical activity, body mass index, nicotine exposure, sleep, diet, blood pressure, lipid profile, and blood glucose. PRSs were assessed individually for 18 cancer types by their independent single-nucleotide polymorphisms previously identified in genome-wide association studies. Multivariable Cox proportional-hazards models were applied to explore the independent and joint associations of CVH and PRS with cancer incidence risk. The results were displayed as hazard ratio (HR) and 95% confidence interval (CI). RESULTS: Compared with low CVH, high CVH was associated with decreased risks of overall cancer and the majority of common cancers, including digestive system [HRs (95% CI): 0.33 (0.23, 0.45)-0.66 (0.58, 0.75)], lung (HR: 0.25; 95% CI: 0.21, 0.31), renal (HR: 0.42; 95% CI: 0.32, 0.56), bladder (HR: 0.55; 95% CI: 0.44, 0.69), breast (HR: 0.83; 95% CI: 0.74, 0.92), and endometrial cancers (HR: 0.39; 95% CI: 0.30, 0.51). For overall cancer in males, there was an interaction between CVH and PRS. Notably, individuals with high CVH across all levels of PRS had lower risks of overall cancer for females and 8 site-specific cancers than those with low CVH and high PRS [HRs (95% CIs): 0.18 (0.12, 0.25)-0.79 (0.71, 0.87)]. CONCLUSIONS: High CVH was related to decreased risks of overall cancer and multiple cancers regardless of genetic predispositions. Our findings underscored the value of improving CVH for cancer prevention in the general population.

Association of total and different food-derived advanced glycation end-products with risks of all-cause and cause-specific mortality.

Background: advanced glycation end-products (AGEs), formed through a series of non-enzymatic reactions, can promote inflammation and oxidative stress. Their accumulation in the body has been linked to cardiovascular disease (CVD) and cancer. However, the association of total AGEs and AGEs from different food sources with risks of all-cause, CVD, and cancer mortality is still unknown. Methods: we conducted a prospective cohort study of a nationally representative sample of 22 124 participants from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 2003-2006. A food frequency questionnaire (FFQ) was utilized to calculate total and different food-derived AGE intake. Associations between various dietary AGE scores and the risk of all-cause, CVD, and cancer mortality were assessed by weighted Cox proportional hazard regression models. Results: over a median follow-up period of 27.1 years, we found that in the general population, AGE scores of both baked foods and meat were risk factors for all-cause, CVD, and cancer mortality. Specially, higher AGE scores in total and those derived from 10 of the 13 food groups were statistically associated with an increased risk of CVD mortality. Egg-, fruit-, and vegetable-derived AGE scores were positively correlated with the risk of cancer mortality. Additionally, there were positive multiplicative and additive interactions between smoking and meat-derived AGE scores on all-cause mortality. Conclusions: high amounts of AGE consumption is associated with an increased risk of CVD mortality, and meat and baked food-derived AGEs were positively linked to all-cause, CVD, and cancer mortalities. Adherence to unhealthy lifestyles, such as smoking, may increase mortality from leading causes in individuals with AGE-enriched diet habits.

EAT-Lancet Diet Pattern, Genetic Predisposition, Inflammatory Biomarkers, and Risk of Lung Cancer Incidence and Mortality.

SCOPE: The association between a planetary and sustainable EAT-Lancet diet and lung cancer remains inconclusive, with limited exploration of the role of genetic susceptibility and inflammation. METHODS AND RESULTS: The study includes 175 214 cancer-free participants in the UK Biobank. Fourteen food components are collected from a 24-h dietary recall questionnaire. A polygenic risk score is constructed through capturing the overall risk variants for lung cancer. Sixteen inflammatory biomarkers are assayed in blood samples. Participants with the highest EAT-Lancet diet scores (≥12) have a lower risk of lung cancer incidence (hazard ratio [HR] = 0.64, 95% confidence interval [CI]: 0.51-0.80) and mortality (HR = 0.65, 95% CI: 0.48-0.88), compared to those with the lowest EAT-Lancet diet scores (≤8). Interestingly, there is a significantly protective trend against both lung adenocarcinoma and lung squamous cell carcinoma with higher EAT-Lancet diet scores. Despite no significant interactions, a risk reduction trend for lung cancer is observed with increasing EAT-Lancet diet scores and decreasing genetic risk. Ten inflammatory biomarkers partially mediate the association between the EAT-Lancet diet and lung cancer risk. CONCLUSION: The study depicts a lower risk of lung cancer conferred by the EAT-Lancet diet associated with lower inflammation levels among individuals with diverse genetic predispositions.

One-dimensional and three-dimensional long-range orientated superstructures of PbSe nanocrystals.

We report the 1D linear, 2D square, 2D honeycomb, and 3D topo-epitaxy long-range superstructures of oriented attached PbSe NCs. In particular, we discovered novel 1D linear and 3D superstructures, which implied different formation mechanisms compared with the PbSe superstructures previously reported. Our study not only demonstrates stronger design capability for oriented-attached PbSe superstructures, but also reveals important information about the interfacial behavior of the PbSe NCs during the self-assembly.

Versatile fabrication of metal sulfide supraparticles by an in situ decomposition-assembly strategy.

Supraparticles (SPs) are of great importance in both fundamental and applied studies due to their emerging collective properties, synergistic effects, and various applications. Metal sulfide nanomaterials are of vital importance in biomedicine, catalysis, battery materials, and other fields. Herein, an in situ decomposition-assembly strategy for the versatile fabrication of metal sulfide SPs is developed. In the fabrication, cysteine molecules and metal cations first react and form coordination polymers, which are then decomposed by heating to produce small-sized metal sulfide nanocrystals. Driven by elimination of the high surface energy of NCs generated by thermal decomposition and the van der Waals attraction, the resulting nanocrystals in situ self-assemble each other and form SP products. In addition to homogeneous Cu2S, CdS, and ZnS products, the proposed system can even be extended to fabricate hybrid Cu2S/Fe2O3 SPs. Furthermore, the SP size can be easily tuned from 10 to 100 nm by adjusting the proportion of cysteine and metal ions. The SPs not only exhibit various properties including photothermal conversion, fluorescence, and magnetism, depending on their composition, but can also combine these properties by the formation of hybrid structures.

Plasma One-Carbon Metabolism-Related Micronutrients and the Risk of Breast Cancer: Involvement of DNA Methylation.

Findings of epidemiologic studies focusing on the association between one-carbon metabolism-related micronutrients and breast cancer risk, along with the involvement of DNA methylation, have been inconsistent and incomprehensive. We conducted a case-control study in China including 107 paired participants and comprehensively detected 12 plasma one-carbon metabolism-related micronutrients. Genomic DNA methylation was measured using an 850 K chip and differential methylation probes (DMPs) were identified. Multivariate logistic regression was performed to estimate the associations between plasma micronutrients and the odds of breast cancer. The mediation of selected DMPs in micronutrient breast cancer associations was examined using mediation analyses. An inverse association of plasma folate, methionine cycling-related micronutrients (methionine, S-adenosylmethionine, and S-adenosylhomocysteine), and all micronutrients in the choline metabolism and enzymatic factor groups, and a positive association of methionine cycling-related cysteine with breast cancer risk were observed. Nine micronutrients (methionine, cysteine, SAM, folate, choline, betaine, P5P, vitamins B2, and B12) were related to global or probe-specific methylation levels (p < 0.05). The selected DMPs mediated the micronutrient breast cancer associations with an average mediation proportion of 36.43%. This study depicted comprehensive associations between circulating one-carbon metabolism-related micronutrients and breast cancer risk mediated by DNA methylation.

Association between diabetes at different diagnostic ages and risk of cancer incidence and mortality: a cohort study.

Background: Different ages for diagnosis of diabetes have diverse effects on risks of cardiovascular disease, dementia, and mortality, but there is little evidence of cancer. This study investigated the relationship between diabetes at different diagnostic ages and risks of cancer incidence and mortality in people aged 37-73 years. Methods: Participants with diabetes in the UK Biobank prospective cohort were divided into four groups: ≤40, 41-50, 51-60, and >60 years according to age at diagnosis. A total of 26,318 diabetics and 105,272 controls (1:4 randomly selected for each diabetic matched by the same baseline age) were included. We calculated the incidence density, standardized incidence, and mortality rates of cancer. Cox proportional hazard model was used to examine the associations of diabetes at different diagnostic ages with cancer incidence and mortality, followed by subgroup analyses. Results: Compared to corresponding controls, standardized incidence and mortality rates of overall and digestive system cancers were higher in diabetes diagnosed at age 41-50, 51-60, and >60 years, especially at 51-60 years. Individuals diagnosed with diabetes at different ages were at higher risk to develop site-specific cancers, with a prominently increased risk of liver cancer since the diagnosis age of >40 years. Significantly, participants with diabetes diagnosed at 51-60 years were correlated with various site-specific cancer risks [hazard ratio (HR) for incidence: 1.088-2.416, HR for mortality: 1.276-3.269]. Moreover, for mortality of digestive system cancers, we observed an interaction effect between smoking and diabetes diagnosed at 51-60 years. Conclusion: Our findings highlighted that the age at diagnosis of diabetes, especially 51-60 years, was critical risks of cancer incidence and mortality and may represent a potential preventative window for cancer.

Association between the Finnish Diabetes Risk Score and cancer in middle-aged and older adults: Involvement of inflammation.

BACKGROUND: Diabetes is associated with increased risk of common cancers. However, evidence of cancer risk in individuals with different diabetes risk is still scarce, and the underlying mechanism remains unknown. Therefore, we aimed to evaluate the relationship between the Finnish Diabetes Risk Score (FINDRISC) and risks of cancer incidence and mortality in a prospective study, and to explore whether low-grade inflammation partially mediated the association. METHODS: A total of 330,384 participants aged 37 to 73 at baseline from the UK Biobank database was included in this study. The Cox proportional hazards model was used to examine the relationship of the FINDRISC and low-grade inflammation with risks of cancer incidence and mortality. Then, we estimated the contribution of higher FINDRISC to risks of overall and site-specific cancers. In addition, the role of low-grade inflammation in the association between FINDRISC and cancer risks was investigated through mediation analysis. RESULTS: The increased FINDRISC was dose-dependently associated with higher incidence and mortality risks of overall cancer and an overwhelming majority of site-specific cancers. The higher FINDRISC was a strong contributor to incidence of eighteen site-specific cancers and mortality of fourteen site-specific cancers, with a population-attributable risk of 8.1 %-39.1 %, 14.2 %-39.7 %, respectively. Additionally, low-grade inflammation mainly mediated the association between the FINDRISC and risks of incidence and mortality of overall cancer, colorectal cancer, etc. CONCLUSIONS: Our findings highlighted the higher FINDRISC as critical risk factors of cancer incidence and mortality, partially mediated by low-grade inflammation. Individuals with increased risk of diabetes are also needed to be concerned about cancer prevention.

Synthesis of Au@Ag core-shell nanocubes containing varying shaped cores and their localized surface plasmon resonances.

We have synthesized Au@Ag core-shell nanocubes containing Au cores with varying shapes and sizes through modified seed-mediated methods. Bromide ions are found to be crucial in the epitaxial growth of Ag atoms onto Au cores and in the formation of the shell's cubic shape. The Au@Ag core-shell nanocubes exhibit very abundant and distinct localized surface plasmon resonance (LSPR) properties, which are core-shape and size-dependent. With the help of theoretical calculation, the physical origin and the resonance mode profile of each LSPR peak are identified and studied. The core-shell nanocrystals with varying shaped cores offer a new rich category for LSPR control through the plasmonic coupling effect between core and shell materials.

Room-temperature superionic-phase nanocrystals synthesized with a twinned lattice.

The engineering of nanoscale features enables the properties of solid-state materials to be tuned. Here, we show the tunable preparation of cuprous sulfide nanocrystals ranging in internal structures from single-domain to multi-domain. The synthetic method utilizes in-situ oxidation to grow nanocrystals with a controlled degree of copper deficiency. Copper-deficient nanocrystals spontaneously undergo twinning to a multi-domain structure. Nanocrystals with twinned domains exhibit markedly altered crystallographic phase and phase transition characteristics as compared to single-domain nanocrystals. In the presence of twin boundaries, the temperature for transition from the ordered phase to the high-copper-mobility superionic phase is depressed. Whereas the superionic phase is stable in the bulk only above ca. 100 °C, cuprous sulfide nanocrystals of ca. 7 nm diameter and a twinned structure are stable in the superionic phase well below ambient temperature. These findings demonstrate twinning to be a structural handle for nanoscale materials design and enable applications for an earth-abundant mineral in solid electrolytes for Li-S batteries.

Shape-dependent ordering of gold nanocrystals into large-scale superlattices.

Self-assembly of individual building blocks into highly ordered structures, analogous to spontaneous growth of crystals from atoms, is a promising approach to realize the collective properties of nanocrystals. Yet the ability to reliably produce macroscopic assemblies is unavailable and key factors determining assembly quality/yield are not understood. Here we report the formation of highly ordered superlattice films, with single crystalline domains of up to half a millimetre in two dimensions and thickness of up to several microns from nanocrystals with tens of nanometres in diameter. Combining experimental and computational results for gold nanocrystals in the shapes of spheres, cubes, octahedra and rhombic dodecahedra, we investigate the entire self-assembly process from disordered suspensions to large-scale ordered superlattices induced by nanocrystal sedimentation and eventual solvent evaporation. Our findings reveal that the ultimate coherence length of superlattices strongly depends on nanocrystal shape. Factors inhibiting the formation of high-quality large-scale superlattices are explored in detail.

Nanodiamond-based nanostructures for coupling nitrogen-vacancy centres to metal nanoparticles and semiconductor quantum dots.

The ability to control the interaction between nitrogen-vacancy centres in diamond and photonic and/or broadband plasmonic nanostructures is crucial for the development of solid-state quantum devices with optimum performance. However, existing methods typically employ top-down fabrication, which restrict scalable and feasible manipulation of nitrogen-vacancy centres. Here, we develop a general bottom-up approach to fabricate an emerging class of freestanding nanodiamond-based hybrid nanostructures with external functional units of either plasmonic nanoparticles or excitonic quantum dots. Precise control of the structural parameters (including size, composition, coverage and spacing of the external functional units) is achieved, representing a pre-requisite for exploring the underlying physics. Fine tuning of the emission characteristics through structural regulation is demonstrated by performing single-particle optical studies. This study opens a rich toolbox to tailor properties of quantum emitters, which can facilitate design guidelines for devices based on nitrogen-vacancy centres that use these freestanding hybrid nanostructures as building blocks.

Controlled synthesis of non-epitaxially grown Pd@Ag core-shell nanocrystals of interesting optical performance.

Pd@Ag core-shell nanocrystals are synthesized through a seed mediated method. Ag shells are found to be grown in a non-epitaxial growth manner, with lots of defects to release the strain originating from lattice mismatch.