Use of symptom diary in primary students: association of nitrogen dioxide with prevalence of symptoms.

Air pollution is a global public health concern, and numerous studies have attempted to identify the health effects of air pollutants, including nitrogen dioxide (NO2). In China, there are few studies investigating the relationship between NO2 exposure and symptoms among children at an individual level. The aim of the study was to evaluate the acute effects of NO2 on prevalence of symptoms of primary students. An environmental and health questionnaire survey was administered to 4240 primary students in seven districts of Shanghai. Daily symptoms, as well as the daily air pollution and meteorological data from each community, were recorded during the corresponding period. A multivariable logistic regression model was utilized to analyze the relationship between the prevalence of symptoms and NO2 exposure in school-age children. A model with interaction items was adopted to estimate the interactive effects of NO2 and confounding factors on symptoms. The average NO2 level in central urban, industrial and rural areas were 62.07 ± 21.66, 54.86 ± 18.32 and 36.62 ± 21.23 µg m-3, respectively. Our findings demonstrate that the occurrence of symptoms was significantly affected by NO2 exposure in the short-term. The largest associations were observed for a 10 µg m-3 increase in 5-day moving average (lag04) NO2 concentration with prevalence of general symptoms (odds ratio [OR] = 1.15, 95% confidence interval [95% CI]: 1.07-1.22), throat symptoms (OR = 1.23, 95% CI: 1.13-1.35) and nasal symptoms (OR = 1.142, 95% CI: 1.02-1.27). Subgroup analysis showed that non-rural areas, boys, nearby environmental pollution source and history of present illness were all susceptible factors to the effects of NO2 exposure. Furthermore, there were interactive effects between NO2 exposure and area types on reported symptoms. NO2 can increase the risk of symptoms in primary students in the short-term, which could be significantly enhanced in central urban and industrial areas.

Interleukin-38 in colorectal cancer: a potential role in precision medicine.

Colorectal cancer (CRC) is a leading cause of cancer-related death, partly due to a lack of reliable biomarkers for early diagnosis. To improve the outcome of CRC, it is critical to provide diagnosis at an early stage using promising sensitive/specific marker(s). Using immunohistochemistry and histopathology, IL-38 expression was determined in tissue arrays of CRC with different TNM status and depth of tumour invasion. Data were compared to IL-38 in adjacent non-cancer tissue and correlated with demographic information, including survival. A substantial reduction of IL-38 was detected in the CRC tissue compared to adjacent non-cancer colonic tissue. IL-38 correlated with the extent of tumour differentiation (P < 0.0001); CRC location in the left side of the colon (P < 0.05), and smaller tumour size (≤ 5 cm; P < 0.05). Receiver operating characteristic (ROC) curve analysis demonstrated both high specificity and high sensitivity of IL-38 for the diagnosis of CRC [area under the curve (AUC) = 0.89)]. By sub-group analysis, AUC of IL-38 for the diagnosis of CRC was higher in poorly differentiated, right-sided CRC or tumour size > 5 cm (all AUC > 0.9). Significantly, longer survival was observed for the IL-38high versus the IL-38low groups in CRC patients (P = 0.04). Survival was also longer for IL-38high patients with lymph node metastasis (P = 0.01) and TNM stage III-IV (P = 0.02). Multivariate analysis demonstrated that IL-38 (P = 0.05) and tumour invasion depth (P = 0.04) were independent factors for survival. High IL38 in CRC is an independent prognostic factor for the longer survival of CRC patients. IL-38 signalling may constitute a therapeutic target in CRC.

IL-36 s in the colorectal cancer: is interleukin 36 good or bad for the development of colorectal cancer?

BACKGROUND AND AIMS: Colorectal cancer (CRC) is a major killer. Host immunity is important in tumorigenesis. Direct comparison among IL-36α, IL-36ß and IL-36γ in the prognosis of CRC is unclear. METHODS: CRC tissue arrays were generated from colorectostomy samples with TNM stage, invasion depth and the demography of these patients (n = 185). Using immunohistochemistry/histopathology, IL-36α, IL-36ß and IL-36γ were determined, in comparison to non-cancer tissues. RESULTS: A significant association was observed between colonic IL-36α, IL-36ß or IL-36γ and the presence of cancer (with all P < 0.0001). Using ROC curve analysis, specificity and sensitivity of IL-36α, IL-36ß or IL-36γ were confirmed, with area under the curve (AUC) values of 0.68, 0.73 and 0.65, respectively. Significant differences in survival were observed between IL-36αhigh and IL-36αlow (P = 0.003) or IL-36γhigh and IL-36γlow (P = 0.03). Survival curves varied significantly when further stratification into sub-groups, on the basis of combined levels of expression of two isotypes of IL-36 was undertaken. A significant difference was observed when levels of IL-36α and IL-36ß were combined (P = 0.01), or a combination of IL-36α plus IL-36γ (P = 0.002). The sub-groups with a combination of IL-36αhigh plus IL-36ßhigh, or IL-36αhigh plus IL-36γlow exhibited the longest survival time among CRC patients. In contrast, the sub-groups of IL-36αlow plus IL-36ßhigh or IL-36αlow plus IL-36γhigh had the shortest overall survival. Using the log-rank test, IL-36αhigh expression significantly improved survival in patients with an invasion depth of T4 (P < 0.0001), lymph node metastasis (P = 0.04), TNM III-IV (P = 0.03) or with a right-sided colon tumour (P = 0.02). Similarly, IL-36γlow expression was significantly associated with improved survival in patients with no lymph node metastasis (P = 0.008), TNM I-II (P = 0.03) or with a left-sided colon tumour (P = 0.05). Multivariate analysis demonstrated that among IL-36α, IL-36ß and IL-36γ, only IL-36α (HR, 0.37; 95% CI, 0.16-0.87; P = 0.02) was an independent factor in survival, using Cox proportional hazards regression analysis. CONCLUSION: IL-36α or IL-36γ are reliable biomarkers in predicting the prognosis of CRC during the later or early stages of the disease, respectively. Combining IL-36α plus IL-36γ appears to more accurately predict the postoperative prognosis of CRC patients. Our data may be useful in the management of CRC.

Effects of filtered fresh air ventilation on classroom indoor air and biomarkers in saliva and nasal samples: A randomized crossover intervention study in preschool children.

To evaluate the short-term effects of filtered fresh air ventilation system on classroom indoor air and biomarkers in saliva and nasal samples in preschool children, a randomized crossover study was conducted in a kindergarten in Shanghai, China in 2016. Two classrooms at the same grade (n = 43) were selected and fresh air ventilation systems (FAVS) with high efficiency particulate air filter (HEPA) were installed. In the first week, FAVS-HEPA was run in one classroom for 2 continuous school days and the other classroom was remained as usual with no use of FAVS-HEPA. After one week of wash-out, the ventilation modes exchanged between two classrooms and another 2 days of intervention were repeated. Real-time indoor and outdoor air pollution and climate factors (PM2.5, Temp and relative humidity (R.H.)) were measured. Saliva and nasal internal mucosa samples were collected immediately at the end of each intervention scenario. Linear mixed-effect regression model was applied to evaluate the effects of intervention on children's health indicators controlling for age, gender, height, BMI and temperature. The results showed, with FAVS-HEPA, the classroom indoor fine particulate matter (PM2.5)(29.1 ±â€¯17.9 µg/m3) was on average significantly lower than that without FAVS-HEPA (85.7 ±â€¯43.2 µg/m3). By regression analysis, each 10 µg/m3 decrease of indoor PM2.5 during the 8 school hours in the first intervention day was associated with an average of 1.76% (95% confidence interval (CI) 0.43-3.08%) increase in saliva lysozyme. This percentage increased to 2.41% (95%CI 0.52-4.26%) if related to the PM2.5 level in 16 school hours over 2 days of intervention. A total of 19 nasal bacterial taxa were lower in subjects exposed to FAVS-HEPA, compared to that with no use of FAVS-HEPA, despite the general bacteria diversity levels in nasal samples were not statistically different. Among others, Providencia species showed significant effects in mediating the associations between higher PM2.5 and lower lysozyme. In conclusion, using FAVS-HEPA was effective in decreasing the classroom indoor PM2.5. Saliva lysozyme, as a non-specific immune biomarker, was significantly inversely associated with indoor PM2.5. Certain nasal bacteria might play key roles in mediating PM2.5 exposure and children's lysozyme levels.

Evaluating the feasibility of a personal particle exposure monitor in outdoor and indoor microenvironments in Shanghai, China.

Existing particulate matter (PM) monitors have too low spatiotemporal resolution to properly characterize individual exposure doses. In order to support health impact assessment, it is essential to develop a better method to assess individual exposure by taking account of varied environments in which people spend their time. Compact light-scattering PM monitors can potentially fill this need. This study was conducted to evaluate feasibility of a low-cost PM monitor (Plantower PMS 7003) in indoor and roadside outdoor microenvironments compared to research-grade instruments in Shanghai, China. The monitors exhibited excellent performance with a high linear response and low bias values both in outdoor and indoor tests. The monitors also showed little confounding bias in low relative humidity environments. Taking into account the accessibility and portability of this monitor, the monitors were able to detect the dynamic nature of individual exposures and provide data and knowledge about human exposure assessments.

Tanshinone IIA Affects Autophagy and Apoptosis of Glioma Cells by Inhibiting Phosphatidylinositol 3-Kinase/Akt/Mammalian Target of Rapamycin Signaling Pathway.

OBJECTIVE: To test the effects of Tanshinone IIA (Tan IIA) on cell viability, cycle, apoptosis, and autophagy of human glioma cell U251 by regulating phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signal pathway. METHODS: Tan IIA and PI3K agonist (740 Y-P) were used to treat glioma cells U251. MTT assay was used to assess cell viability and flow cytometry was used to detect cell apoptosis and cell cycle. The expressions of apoptosis-related proteins (Bcl-2 and Bax), autophagy-related proteins (LC3B and Beclin 1) and PI3K/Akt/mTOR signal pathway-associated proteins (p-PI3K, p-Akt and p-mTOR) were evaluated by Western blotting. RESULTS: Tan IIA decreased the expression of p-PI3K and p-Akt proteins, inhibited cell viability and promoted apoptosis. Meanwhile, the expression of Bax increased, while the expression of Bcl-2 decreased. In addition, Tan IIA promoted autophagy in U251 glioma cells and raised the expression of LC3B and Beclin 1. However, 740 Y-P played a reversed role of Tan IIA in cell viability, cycle, apoptosis, and autophagy of U251 cells. CONCLUSION: Tan IIA could suppress the viability of U251 cells and induce cell apoptosis and autophagy, which might be related to the inhibition of the PI3K/Akt/mTOR signal pathway.

Facile preparation of re-dispersible/amphoteric nanochitin powder via choline chloride/propanedioic composite for stabilizing Pickering emulsions.

Choline chloride (ChCl)/propanedioic acid (PA) based hydrated composites are synthesized for producing nanochitins from crab shell in this work. The yield of nanochitin remains higher than 75 %, even if the water content reaches 80 %. ChCl is found necessary for the successful nano-fibrillation of chitin. However, PA contributes more to the yield improvement of nanochitin. ChCl mediated PA hydrolysis leads to the successful grafting of carboxyl groups in nanochitins, contributing to its amphoteric dispersed nature. After salt-induced separation and freeze-drying treatment, dried nanochitin powder can be prepared and found to disperse well either in acidic or alkaline suspension, exhibiting efficient drying/redispersion performance. The well amphoteric and drying/redispersion nature both benefit the facile preparation of nanochitin-based Pickering emulsions. For Pickering emulsion prepared under different pH, creaming only appears under acidic conditions (pH 3) for which the creaming index reaches 10.56 % after 30 days of storage. No obvious de-emulsification can be observed under pH 7 and 10. The efficient amphoteric and drying/redispersion nature together with the simplified preparation process of nanochitins are believed to facilitate the processing and practical applications of nanochitin.

Exploring the clinical significance of IL-38 correlation with PD-1, CTLA-4, and FOXP3 in colorectal cancer draining lymph nodes.

Introduction: Colorectal cancer (CRC) presents a substantial challenge characterized by unacceptably high mortality and morbidity, primarily attributed to delayed diagnosis and reliance on palliative care. The immune response of the host plays a pivotal role in carcinogenesis, with IL-38 emerging as a potential protective factor in CRC. However, the precise involvement of IL-38 among various leucocytes, its interactions with PD-1/PD-L1, and its impact on metastasis require further elucidation. Results: Our investigation revealed a significant correlation between IL-38 expression and metastasis, particularly concerning survival and interactions among diverse leucocytes within draining lymph nodes. In the mesentery lymph nodes, we observed an inverse correlation between IL-38 expression and stages of lymph node invasions (TNM), invasion depth, distance, and differentiation. This aligns with an overall survival advantage associated with higher IL-38 expression in CRC patients' nodes compared to lower levels, as well as elevated IL-38 expression on CD4+ or CD8+ cells. Notably, a distinct subset of patients characterized by IL-38high/PD-1low expression exhibited superior survival outcomes compared to other combinations. Discussion: Our findings demonstrate that IL-38 expression in colorectal regional nodes from CRC patients is inversely correlated with PD-1/PD-L1 but positively correlated with infiltrating CD4+ or CD8+ lymphocytes. The combined assessment of IL-38 and PD-1 expression in colorectal regional nodes emerges as a promising biomarker for predicting the prognosis of CRC.

CD64 plays a key role in diabetic wound healing.

Introduction: Wound healing poses a clinical challenge in diabetes mellitus (DM) due to compromised host immunity. CD64, an IgG-binding Fcgr1 receptor, acts as a pro-inflammatory mediator. While its presence has been identified in various inflammatory diseases, its specific role in wound healing, especially in DM, remains unclear. Objectives: We aimed to investigate the involvement of CD64 in diabetic wound healing using a DM animal model with CD64 KO mice. Methods: First, we compared CD64 expression in chronic skin ulcers from human DM and non-DM skin. Then, we monitored wound healing in a DM mouse model over 10 days, with or without CD64 KO, using macroscopic and microscopic observations, as well as immunohistochemistry. Results: CD64 expression was significantly upregulated (1.25-fold) in chronic ulcerative skin from DM patients compared to non-DM individuals. Clinical observations were consistent with animal model findings, showing a significant delay in wound healing, particularly by day 7, in CD64 KO mice compared to WT mice. Additionally, infiltrating CD163+ M2 macrophages in the wounds of DM mice decreased significantly compared to non-DM mice over time. Delayed wound healing in DM CD64 KO mice correlated with the presence of inflammatory mediators. Conclusion: CD64 seems to play a crucial role in wound healing, especially in DM conditions, where it is associated with CD163+ M2 macrophage infiltration. These data suggest that CD64 relies on host immunity during the wound healing process. Such data may provide useful information for both basic scientists and clinicians to deal with diabetic chronic wound healing.

Development and external validation of a transfer learning-based system for the pathological diagnosis of colorectal cancer: a large emulated prospective study.

Background: The progress in Colorectal cancer (CRC) screening and management has resulted in an unprecedented caseload for histopathological diagnosis. While artificial intelligence (AI) presents a potential solution, the predominant emphasis on slide-level aggregation performance without thorough verification of cancer in each location, impedes both explainability and transparency. Effectively addressing these challenges is crucial to ensuring the reliability and efficacy of AI in histology applications. Method: In this study, we created an innovative AI algorithm using transfer learning from a polyp segmentation model in endoscopy. The algorithm precisely localized CRC targets within 0.25 mm² grids from whole slide imaging (WSI). We assessed the CRC detection capabilities at this fine granularity and examined the influence of AI on the diagnostic behavior of pathologists. The evaluation utilized an extensive dataset comprising 858 consecutive patient cases with 1418 WSIs obtained from an external center. Results: Our results underscore a notable sensitivity of 90.25% and specificity of 96.60% at the grid level, accompanied by a commendable area under the curve (AUC) of 0.962. This translates to an impressive 99.39% sensitivity at the slide level, coupled with a negative likelihood ratio of <0.01, signifying the dependability of the AI system to preclude diagnostic considerations. The positive likelihood ratio of 26.54, surpassing 10 at the grid level, underscores the imperative for meticulous scrutiny of any AI-generated highlights. Consequently, all four participating pathologists demonstrated statistically significant diagnostic improvements with AI assistance. Conclusion: Our transfer learning approach has successfully yielded an algorithm that can be validated for CRC histological localizations in whole slide imaging. The outcome advocates for the integration of the AI system into histopathological diagnosis, serving either as a diagnostic exclusion application or a computer-aided detection (CADe) tool. This integration has the potential to alleviate the workload of pathologists and ultimately benefit patients.

Preference for Self-Resembling Male Faces in Gay Men in China.

Self-resemblance refers to couples with similar characteristics, also known as homogamy or positive assortative mating. Previous studies have indicated that heterosexual men and women prefer partners with similar facial features. In this study, we examined whether Chinese gay men preferred self-resemblance to faces. The participants (N = 70) completed a personal information questionnaire and preference selection task involving 10 pairs of self-resembling/control male faces. Ten pairs of self-resembling/control male faces of each participant were also rated by another gay man. The results revealed that the proportion of the participants who chose self-resembling faces was significantly higher than that of the control faces. However, the preference for "self-resembling" and control faces by other-rating was not significantly different. These findings indicate homogeneity in facial preferences among gay men.

Facile modification of nanochitin in aqueous media for stabilizing tea tree oil based Pickering emulsion with prolonged antibacterial performance.

Nanochitins have been explored for preparing Pickering Emulsions, however its application is restricted by its simplex disperse nature. It was hypothesized that zwitterionic nanochitins should be capable of stabilizing oil/water (O/W) interfaces in wider pH range. Furthermore, the control of their size, disperse nature and self-assembly performance suggest the formulation of tunable emulsions. Zwitterionic nanochitins were prepared via Schiff base reaction. A systematic study was performed analyzing the disperse nature, fibril morphology, surface characteristic of modified nanochitins. Oil-in-Water Pickering Emulsions stabilized by modified nanochitins were formulated and emulsion stability was analyzed as function of concentration, pH and self-assembly property and further applied for prolonged antibacterial applications. Comparing freshly prepared nanochitins, neutral/alkaline stably dispersed nanochitins can be prepared while maintaining fibril characteristics such as fibril size, crystallinity, thermal stability and so on. Better suspension stability of modified nanochitins under alkaline conditon together with the self assembly performance resulting from amino groups and carboxyl groups benefit the enhanced emulsion stability under nanochitins concentreation of 0.2 %. Encapsulation of tea tree oil in Pickering Emulsions prolongs the diffusion rate oil in the aqueous environment, thus resulting prolongs its antibacterial performance against E. coli and B. subtilis.

Hsa_circ_0014784-induced YAP1 promoted the progression of pancreatic cancer by sponging miR-214-3p.

BACKGROUND: Pancreatic cancer (PC) is one of the most common gastrointestinal tumors globally. Former investigations discovered that circular RNAs (circRNAs) play an important role in PC development. circRNAs belong to a new class of endogenous noncoding RNAs, which have been found to mediate the progression of diverse types of tumors. Nevertheless, the roles of circRNAs and the underlying regulatory mechanisms in PC remain unknown. METHODS: In this study, our team employed next-generation sequencing (NGS) to examine the abnormal circRNA expression in PC tissues. The circRNA expression in PC cell lines and tissues was detected. Then, regulatory mechanism and targets were examined with bioinformatics analysis, luciferase reporting analysis, Transwell migration, 5-ethynyl-2'-deoxyuridine, and CCK-8 analysis. An in vivo experiment was employed to elucidate hsa_circ_0014784 roles in PC tumor growth and metastasis. RESULTS: The results showcased abnormal circRNA expression in PC tissues. Our lab also found that hsa_circ_0014784 expression incremented in PC tissues and cell lines, implying that hsa_circ_0014784 functioned in PC progression. hsa_circ_0014784 downregulation inhibited PC proliferation and invasion in vivo and in vitro. The bioinformatics and luciferase report data validated that both miR-214-3p and YAP1 were hsa_circ_0014784 binding partners. The overexpression of YAP1 reversed the migration, proliferation, and epithelial - mesenchymal transition (EMT) of PC cells and the angiogenic differentiation of HUVECs after miR-214-3p overexpression. CONCLUSION: Taken together, our study found that hsa_circ_0014784 downregulation decremented invasion, proliferation, EMT, and angiogenesis of PC by regulating miR-214-3p/YAP1 signaling.

Construction and evaluation of hourly average indoor PM2.5 concentration prediction models based on multiple types of places.

Background: People usually spend most of their time indoors, so indoor fine particulate matter (PM2.5) concentrations are crucial for refining individual PM2.5 exposure evaluation. The development of indoor PM2.5 concentration prediction models is essential for the health risk assessment of PM2.5 in epidemiological studies involving large populations. Methods: In this study, based on the monitoring data of multiple types of places, the classical multiple linear regression (MLR) method and random forest regression (RFR) algorithm of machine learning were used to develop hourly average indoor PM2.5 concentration prediction models. Indoor PM2.5 concentration data, which included 11,712 records from five types of places, were obtained by on-site monitoring. Moreover, the potential predictor variable data were derived from outdoor monitoring stations and meteorological databases. A ten-fold cross-validation was conducted to examine the performance of all proposed models. Results: The final predictor variables incorporated in the MLR model were outdoor PM2.5 concentration, type of place, season, wind direction, surface wind speed, hour, precipitation, air pressure, and relative humidity. The ten-fold cross-validation results indicated that both models constructed had good predictive performance, with the determination coefficients (R2) of RFR and MLR were 72.20 and 60.35%, respectively. Generally, the RFR model had better predictive performance than the MLR model (RFR model developed using the same predictor variables as the MLR model, R2 = 71.86%). In terms of predictors, the importance results of predictor variables for both types of models suggested that outdoor PM2.5 concentration, type of place, season, hour, wind direction, and surface wind speed were the most important predictor variables. Conclusion: In this research, hourly average indoor PM2.5 concentration prediction models based on multiple types of places were developed for the first time. Both the MLR and RFR models based on easily accessible indicators displayed promising predictive performance, in which the machine learning domain RFR model outperformed the classical MLR model, and this result suggests the potential application of RFR algorithms for indoor air pollutant concentration prediction.

More income, less depression? Revisiting the nonlinear and heterogeneous relationship between income and mental health.

This paper uses a large-scale nationally representative dataset to examine the nonlinear effect of income on mental health. To investigate their causal relationship, the exogenous impact of automation on income is utilized as the instrument variable (IV). In addition, to explore their nonlinear relationship, both income and its quadratic term are included in regressions. It is found that the impact of income on mental health is U-shaped rather than linear. The turning point (7.698) of this nonlinear relation is near the midpoint of the income interval ([0, 16.113]). This suggests that depression declines as income increases at the lower-income level. However, beyond middle income, further increases in income take pronounced mental health costs, leading to a positive relationship between the two factors. We further exclude the possibility of more complex nonlinear relationships by testing higher order terms of income. In addition, robustness checks, using other instrument variables and mental health indicators, different IV models and placebo analysis, all support above conclusions. Heterogeneity analysis demonstrates that males, older workers, ethnic minorities and those with lower health and socioeconomic status experience higher levels of depression. Highly educated and urban residents suffer from greater mental disorders after the turning point. Religious believers and Communist Party of China members are mentally healthier at lower income levels, meaning that religious and political beliefs moderate the relationship between income and mental health.

Re-dispersible chitin nanofibrils with improved stability in green solvents for fabricating hydrophobic aerogels.

A facile formic acid (15 M) hydrolysis method was established to prepare chitin nanofibrils that exhibited much longer fibril size (538-1000 nm) and higher yield (87-95%) than traditional hydrochloric acid hydrolyzed ones. Interestingly, these chitin nanofibrils can well be dispersed in water/TBA or water/ethanol binary solvents, which can contribute to the functionality of chitin nanofibrils in different way. On one hand, chitin nanofibril aerogels with tunable inter-structure were prepared via direct freeze-drying of chitin nanofibril/water/TBA dispersion with specific surface area could be promoted 69%. Meantime, re-dispersibility was realized, and the higher concentration of TBA used, the better re-disperse performance. On the other hand, due to the well disperse nature of chitin nanofibrils in water/ethanol (ethanol can reach 90%), they can be well mixed with zein. Whereby, the hydrophobic chitin nanofibril/zein composite aerogels were prepared and showed great potential in absorbing oil or organic spillage off water.

Zwitterionic chitin nanocrystals mediated composite and self-assembly with cellulose nanofibrils.

Zwitterionic dispersed chitin nanocrystals and TEMPO oxidized cellulose nanofibrils can be well mixed and self-assembled to be hydrogels/membranes. Active carboxyl groups ensure the well mixing of zwitterionic chitin nanocrystals and cellulose nanofibrils under neutral and alkaline condition. Electrostatic attraction between amino groups in chitin nanocrystals and carboxyl groups in chitin nanocrystals and cellulose nanofibrils further endows self-assemble property of composite suspensions. Simple standing for 12 h at room temperature is found enough for preparing self-assembled composite hydrogels. By 1-(3-dimethy-laminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxy succinimide (EDC/NHS) mediated chemical crosslinking, the storage modulus of composite hydrogel can achieve almost 8 times higher than self-assembled hydrogel. Well dispersed composite suspensions also can be transformed to be membranes via filtration treatment. The strain increases almost 2.3 times higher with similar tensile strength for cellulose nanofibril rich samples, and chitin nanocrystals mainly contributes to the enhancement in strain of composite membranes.

Preparation of nanochitin hydrogel with adjustable inter-structure by sequencial genipin crosslinking and ice-templating under acid condition.

In this work, genipin crosslinked chitin nanofibril hydrogels/cryogels were successfully prepared. Due to the acidic disperse nature of positively charged chitin fibrils, the pH nature for the chemical crosslinking between chitin nanofibrils and genipin was restricted under 5.0. The pH nature and crosslinking temperature were found greatly influence the efficient chemical crosslinking between chitin nanofibril and genipin. Further ice templated crosslinking was found effective enhancing the mechanical properties of resulting chitin nanofibril hydrogels/cryogels. The cryogel prepared by genipin-crosslinked DEChNs showed interconnected pores, presenting a state of stacking layers. In addition, the deposition of hydroxyapatite (HA) on the surface of chitin nanofibril scaffolds was found effective for improving chondrocyte attachments and growths. The cells viability indicated the good cell compatibility of the cryogel. All the results indicated that the cryogel prepared by genipin-crosslinked DEChNs showed a potential for tissue engineering applications.

All-natural and biocompatible cellulose nanocrystals films with tunable supramolecular structure.

Herein, nanocomposites films were prepared via the facile casting method by incorporating cellulose nanocrystals (CNCs) with arabinogalactan (AG), galactomannan (GM) or konjac glucomannan (KGM) respectively. The introduced polysaccharides maintained the transparency of CNCs films and promoted the UV blocking properties. In addition, mechanical strength of the nanocomposite films was greatly improved after the combination of polysaccharides. The interactions of hydroxyl-abundant macromolecules, smoother and tighter morphological structures, as well as the disturbed crystal structure were proved to be responsible for the improved properties. Hydrophilic lattice planes of cellulose crystallites were determined to interact with polysaccharides resulting in lower crystallite sizes and crystallinity. The cell culture assay revealed that the films had no cytotoxicity and presented a satisfactory cytocompatibility, because of the polysaccharides from plant cell walls introduced into the films. Therefore, the biocompatible nanocomposites films can be tuned by the addition of polysaccharides, which show great potentials for materials modification in optical, packaging and biomedical fields.

Quantifying cultural tightness-looseness in Ecuador.

Cultural tightness-looseness represents the degree to which a particular culture possesses strong behavioral norms, and the degree to which members of that culture are likely to sanction individuals who deviate from those norms. While tightness-looseness has been quantified for a large and growing number of countries around the world, there are many countries where a tightness-looseness score has yet to be determined, thus impeding the inclusion of those countries in cross-cultural research with a tightness-looseness focus. There is a dearth of research on cultural tightness-looseness in South America in particular. We report results from a national survey of 1,265 Ecuadorian residents which provided quantification of the relatively tight culture of Ecuador.