Burden of biliary tract carcinoma in China (1990-2021): Findings from the 2021 Global Burden of Disease Study.

Biliary tract carcinoma (BTC) is a group of malignant tumors that originate in the digestive system and occurs with a high incidence in China. Few consistent and comparable assessments of BTC disease burden have been conducted at national or subnational levels, and little is known about the demographic, temporal, and geographic patterns of epidemiological characteristics and disease burden of BTC in China. The incidence, mortality, disability-adjusted life-years (DALYs), years of life lost (YLLs) due to premature death and years lived with disability (YLDs) of BTC were comprehensively examined by age, sex, and calendar year in the Chinese population, using the methodological framework and analytical strategies used for the 2021 Global Burden of Disease study. All-age incidence increased from 17,077 to 51,720 between 1990 and 2021, and the age-standardized incidence rate rose by 13.62%; all-age deaths increased from 17,251 to 37,833, but the age-standardized mortality rate fell by nearly one-fifth. The DALYs rose by 89.57% while the age-standardized DALY rate fell by 23.24%. Variations of the tendencies in BTC burden were found between sexes and age groups. Data for each provincial region indicate that coastal eastern provincial regions have higher incidence and YLD levels, whereas northern provincial regions have higher mortality, DALY, and YLL levels. The proportions of DALYs attributable to high body mass index (BMI) illustrate the growing attribution obesity has made, and high BMI usually puts more burden on northern provincial regions. These results provide evidence to support precise, targeted, and customed public health strategies aimed at enhancing biliary tract health among the Chinese population.

Synchronous and efficient removal of carbon, nitrogen, and phosphorus from actual rural sewage by composite wetlands enhanced with functional fillers.

A composite wetland (CECW) was constructed by introducing P-adsorption filler (EPAF) and activated sludge into traditional wetlands for treating actual sewage. The results showed that EPAF improved P removal through physico-chemical adsorption, and it could be stably regenerated after adsorption saturation without potential risks. Meanwhile, zeolite promoted NH4+-N reduction in sewage by cation exchange. In addition, simultaneous biological removal of carbon, nitrogen, and phosphorus was achieved through nitrification, denitrification, anammox, and aerobic P-accumulation processes induced by Nitrobacter, Proteus Hauser, Candidatus Paracaedibacter, and Brevundimonas. Under the coupling of filler interception/adsorption, microbial assimilation/transformation, flocculation, and plant uptake, CECW obtained the removal rates of 93.22 %, 85.75 %, 91.80 %, 95.38 %, 97.07 %, and 78.05 % for turbidity, TN, NH4+-N, TP, PO43--P, and TCOD, which met the Class 1A standard (GB18918-2002). Therefore, the experiment systematically investigated the effects and mechanism of CECW in treating actual sewage, which could provide reference for rural sewage treatment and sludge utilization.

Pan-immune-inflammation value as a prognostic biomarker for colon cancer and its variation by primary tumor location.

BACKGROUND: A growing body of research indicates significant differences between left-sided colon cancers (LCC) and right-sided colon cancers (RCC). Pan-immune-inflammation value (PIV) is a systemic immune response marker that can predict the prognosis of patients with colon cancer. However, the specific distinction between PIV of LCC and RCC remains unclear. AIM: To investigate the prognostic and clinical significance of PIV in LCC and RCC patients. METHODS: This multicenter retrospective cohort study included 1510 patients with colon cancer, comprising 801 with LCC and 709 with RCC. We used generalized lifting regression analysis to evaluate the relative impact of PIV on disease-free survival (DFS) in these patients. Kaplan-Meier analysis, as well as univariate and multivariate analyses, were used to examine the risk factors for DFS. The correlation between PIV and the clinical characteristics was statistically analyzed in these patients. RESULTS: A total of 1510 patients {872 female patients (58%); median age 63 years [interquartile ranges (IQR): 54-71]; patients with LCC 801 (53%); median follow-up 44.17 months (IQR 29.67-62.32)} were identified. PIV was significantly higher in patients with RCC [median (IQR): 214.34 (121.78-386.72) vs 175.87 (111.92-286.84), P < 0.001]. After propensity score matching, no difference in PIV was observed between patients with LCC and RCC [median (IQR): 182.42 (111.88-297.65) vs 189.45 (109.44-316.02); P = 0.987]. PIV thresholds for DFS were 227.84 in LCC and 145.99 in RCC. High PIV (> 227.84) was associated with worse DFS in LCC [PIV-high: Adjusted hazard ratio (aHR) = 2.39; 95% confidence interval: 1.70-3.38; P < 0.001] but not in RCC (PIV-high: aHR = 0.72; 95% confidence interval: 0.48-1.08; P = 0.114). CONCLUSION: These findings suggest that PIV may predict recurrence in patients with LCC but not RCC, underscoring the importance of tumor location when using PIV as a colon cancer biomarker.

Post-heading dry-matter transport and nutrient uptake differentiate hybrid and inbred indica rice in the double-cropping system in South China.

Introduction: Hybrid rice demonstrated superior performance in enhancing yield and efficiency in rice production compared to inbred rice. Nevertheless, the underlying mechanism responsible for the increased yield and efficiency of hybrid rice in South China's double-cropping rice region remains understudied. Methods: Field experiments over two consecutive years were conducted. Firstly, yield variations among 20 inbred and 15 hybrid rice cultivars prevalent in South China's double-cropping rice system were examined. Secondly, selecting representative hybrid and inbred rice cultivars with significant yield disparities were carried out on further analyzing dry-matter production, source-sink relationships, and nutrient absorption and utilization in both rice types. Results: Hybrid rice displayed an average grain yield of 8.07 and 7.22 t hm-2 in the early and late seasons, respectively, which corresponds to a 12.29% and 13.75% increase over inbred rice with statistically significant differences. In comparison to inbred rice, hybrid rice exhibited enhanced nitrogen concentration in leaves at the heading stage (15.48-16.20%), post-heading dry matter accumulation (52.62-73.21%), post-heading dry matter conversion rate (29.23-34.12%), and harvest index (17.31-18.37%). Additionally, grain nitrogen and phosphorus uptake in hybrid rice increased by 11.88-22.50% and 16.38-19.90%. Hybrid rice mainly improved post-heading nitrogen and phosphorus uptake and transport, while not total nitrogen and phosphorus uptake. Internal nitrogen and phosphorus use efficiency enhanced by 9.83%-14.31% and 10.15%-13.66%, respectively. Post-heading dry matter accumulation, harvest index, grain nitrogen and phosphorus uptake, and internal nitrogen and phosphorus use efficiency exhibited significant positive linear correlations with grain yield. Discussion: The period from heading to maturity is critical for enhancing hybrid rice yield and efficiency. Improving photosynthetic capacity during this period and promoting nutrient transport to grains serve as crucial pathways for increasing grain yield and efficiency. This study is of great significance for further improvement grain yield and breeding rice cultivars with high-yield and high nutrients use efficiency for South China's double-cropped rice system.

Chemometrics and sensomics-assisted identification of key odorants responsible for retort odor in shelf-stored green tea infusion: A case study of Biluochun.

The deterioration of aroma quality in tea beverages during the shelf life is a significant issue. In this study, sensomics techniques were employed to identify the characteristic factor contributing to aroma degradation in green tea infusion. Samples A (no/faint retort odor) and B (high intensity retort odor) were selected based on their retort-like odor intensity after heat treatment simulating shelf-life conditions. The key odorants were identified through a combination of chemometrics analysis, comparative aromatic extract dilution analysis (cAEDA), detection frequency analysis (DFA), and odor-specific magnitude estimation (OSME). Subsequently, eight odorants, including linalool (892.451 µg/L), (E)-ß-damascenone (5.105 µg/L), phenylacetaldehyde (27.720 µg/L), nonanal (2201.439 µg/L), α-terpineol (7.166 µg/L), geraniol (0.499 µg/L), theaspirane (0.044 µg/L), and 2-hydroxy-5-methylacetophenone (2.973 µg/L), were identified as the key substances contributing to the retort-like odor in sample B. Aroma recombination and omission test further demonstrated that elevated concentrations of nonanal, geraniol, phenylacetaldehyde, and theaspirane might be the primary reasons for the retort odor observed in samples.

Evaluation of a new scoring system for assessing nerve invasion in resected pancreatic cancer: A single-center retrospective analysis.

Nerve invasion (NI) is a characteristic feature of pancreatic cancer. Traditional dichotomous statements on the presence of NI are unreasonable because almost all cases exhibit NI when sufficient pathological sections are examined. The critical implications of NI in pancreatic cancer highlight the need for a more effective criterion. This study included 511 patients, who were categorized into a training group and a testing group at a ratio of 7:3. According to the traditional definition, NI was observed in 91.2 % of patients using five pathological slides in our study. The prevalence of NI increased as more pathological slides were used. The criterion of 'two points of intraneural (endoneural) invasion in the case of four pathological slides' has the highest receiver operating characteristic (ROC) score. Based on this new criterion, NI was proved to be an independent prognostic factor for overall survival (OS) and disease-free survival (DFS) and was also correlated with tumor recurrence (P = 0.004). Interestingly, gemcitabine-based chemotherapy regimen is an independent favorable factor for patients with high NI. In the high NI group, patients who received a gemcitabine-based regimen exhibited a better prognosis than those who did not receive the gemcitabine-based regimen for OS (P = 0.000) and DFS (P = 0.001). In conclusion, this study establishes assessment criteria to evaluate the severity of NI in order to predict patient outcomes.

The mechanism of action and chemical synthesis of FDA newly approved drug molecules.

In 2023, the U.S. Food and Drug Administration has approved 29 small molecule drugs. These newly approved small molecule drugs possess the distinct scaffolds, thereby exhibiting diverse mechanisms of action and binding modalities. Moreover, the marketed drugs have always been an important source of new drug development and creative inspiration, thereby fostering analogous endeavors in drug discovery that potentially extend to the diverse clinical indications. Therefore, conducting a comprehensive evaluation of drug approval experience and associated information will facilitate the expedited identification of highly potent drug molecules. In this review, we comprehensively summarized the relevant information regarding the clinical applications, mechanisms of action and chemical synthesis of 29 small molecule drugs, with the aim of providing a promising structural basis and design inspiration for pharmaceutical chemists.

[Population structure and fruiting ability of Rosa persica]. / 单叶蔷薇种群结构与结实能力.

We analyzed age structure and dynamics, spatial distribution patterns, and reproductive capabilities of four Rosa persica populations in Xinjiang, to evaluate the survival status of the species and explore the reasons behind its endangerment. The results showed that the populations had fewer individuals in the youngest (Ⅰ) and oldest (Ⅵ-Ⅷ) age classes, with a predominance of middle-aged individuals, resulting in an irregular pyramid-shaped distribution, described as "high in the middle, low on both sides". The populations were generally growing, but were susceptible to external environmental disturbances (Vpi'＞0, Pmax＞0). The mortality rate (qx) and vanish rate (Kx) peaked at age Ⅴ, leading to a sharp decline in plant abundance. The life expectancy (ex) decreased progressively with the increases of age class, reaching its lowest at age Ⅷ, which indicated minimal vitality at this stage. A time sequence analysis predicted a future dominance of individuals at age Ⅴ-Ⅷ, suggesting an aging trend. Spatially, the four populations were predominantly clumped, with the intensity of clumping ranked from highest to lowest as P4, P3, P1, and P2. P3 and P4 exhibited better reproductive capabilities than P1 and P2. There was a significant positive correlation between hundred-fruit weight and plant height and crown width, and between total seed number and crown width and hundred-fruit weight.

The disease burden of bladder cancer and its attributable risk factors in five Eastern Asian countries, 1990-2019: a population-based comparative study.

BACKGROUNDS: The study aimed to estimate bladder cancer burden and its attributable risk factors in China, Japan, South Korea, North Korea and Mongolia from 1990 to 2019, to discuss the potential causes of the disparities. METHODS: Data were obtained from the Global Burden of Disease Study 2019. The annual percent change (APC) and average annual percent change (AAPC) were calculated by Joinpoint analysis, and the independent age, period and cohort effects were estimated by age-period-cohort analysis. RESULTS: In 2019, the highest incidence (7.70 per 100,000) and prevalence (51.09 per 100,000) rates of bladder cancer were in Japan, while the highest mortality (2.31 per 100,000) and DALY rates (41.88 per 100,000) were in South Korea and China, respectively. From 1990 to 2019, the age-standardized incidence and prevalence rates increased in China, Japan and South Korea (AAPC > 0) and decreased in Mongolia (AAPC < 0), while mortality and DALY rates decreased in all five countries (AAPC < 0). Age effects showed increasing trends for incidence, mortality and DALY rates, while the prevalence rates increased first and then decreased in older groups. The cohort effects showed downward trends from 1914-1918 to 2004-2008. Smoking was the greatest contributor and males had the higher burden than females. CONCLUSION: Bladder cancer was still a major public health problem in East Asia. Male and older population suffered from higher risk, and smoking played an important role. It is recommended that more efficient preventions and interventions should be operated among high-risk populations, thereby reduce bladder cancer burden in East Asia.

Global prevalence of liver disease in human and domestic animals caused by Fasciola: A systematic review and meta-analysis.

Background: Liver disease caused by Fasciola is a significant zoonotic and parasitic disease with substantial economic impacts on humans and animals. Many studies have looked at the prevalence of fasciolis worldwide, yet the overall prevalence and risk factors in cattle, ruminants, and humans remains unknown. Methods: We conducted a systematic review and meta-analysis to estimate the global prevalence and risk factors of fascioliasis in humans and domestic ruminants. With this aim, we searched PubMed, ScienceDirect, Web of Science, and Scopus from inception to 8 December 2022 for studies reporting the prevalence of fascioliasis in humans or domestic ruminants post-2000. We then used random effects models to describe the prevalence of fascioliasis; trim-and-fill analysis and Egger's test to assess publication bias; and meta-regression and sensitivity analyses to examine the risk factors for prevalence and heterogeneity. Results: We retrieved 4422 articles, with 371 being included in the analysis, as they concerned fascioliasis in humans and ruminants globally. The pooled prevalence of bovine fasciolosis was 17%, while ovine fasciolosis and human fascioliasis had pooled prevalences of 13% and 5%, respectively. We also conducted subgroup analyses by continents, countries, Fasciola species, sampling years, altitude, rainfall, temperature, humidity, age, sex, feeding mode, and residence. Here, altitude and age emerged as risk factors associated with an increased prevalence of fascioliasis. Both the trim-and-fill analysis and Egger's test confirmed the presence of publication bias, while the sensitivity analysis showed that the omission of any single study did not significantly influence the combined pooled prevalence. Conclusions: Fascioliasis is a widely prevalent zoonosis among humans and livestock worldwide. Strategies targeting risk factors such as altitude and age are urgently needed for prevention and control of this disease, which will consequently reduce Fasciola infection. Additionally, given the inadequacy or absence of data in some countries, greater attention should be paid to Fasciola infection, with further epidemiological studies focussing on improving data quality.

Binaphthyl-based chiral covalent organic frameworks for chiral drug separation.

Separation of racemic drugs is of great importance and interest in chemistry and pharmacology. Here, we report the bottom-up synthesis of the binaphthyl-based chiral covalent organic frameworks (CCOFs), (R)-BHTP-COF. Then, high-performance liquid chromatography (HPLC) columns were prepared using (R)-BHTP-COF as a chiral stationary phase (CSP). Racemic ibuprofen was successfully baseline-separated on (R)-BHTP-COF-based CSP, and achieved excellent selectivity (α = 2.32) and chromatographic resolution (Rs = 3.39) factors. Meanwhile, the separation of six racemic drugs by the (R)-BHTP-COF-packed column exhibited high resolution, selectivity, and durability. The successful applications indicate the great potential of CCOFs as a novel stationary phase for efficient HPLC separation.

Novel Function of Osteocalcin in Chondrocyte Differentiation and Endochondral Ossification Revealed on a CRISPR/Cas9 bglap-bglap2 Deficiency Mouse Model.

Endochondral ossification is the process by which cartilage is mineralized into bone, and is essential for the development of long bones. Osteocalcin (OCN), a protein abundant in bone matrix, also exhibits high expression in chondrocytes, especially hypertrophic chondrocytes, while its role in endochondral ossification remains unclear. Utilizing a new CRISPR/Cas9-mediated bglap-bglap2 deficiency (OCNem) mouse model generated in our laboratory, we provide the first evidence of OCN's regulatory function in chondrocyte differentiation and endochondral ossification. The OCNem mice exhibited significant delays in primary and secondary ossification centers compared to wild-type mice, along with increased cartilage length in growth plates and hypertrophic zones during neonatal and adolescent stages. These anomalies indicated that OCN deficiency disturbed endochondral ossification during embryonic and postnatal periods. Mechanism wise, OCN deficiency was found to increase chondrocyte differentiation and postpone vascularization process. Furthermore, bone marrow mesenchymal stromal cells (BMSCs) from OCNem mice demonstrated an increased capacity for chondrogenic differentiation. Transcriptional network analysis implicated that BMP and TGF-ß signaling pathways were highly affected in OCNem BMSCs, which is closely associated with cartilage development and maintenance. This elucidation of OCN's function in chondrocyte differentiation and endochondral ossification contributes to a more comprehensive understanding of its impact on skeletal development and homeostasis.

Effect of "He Tiao Du Ren An Shen Acupuncture" on restless leg syndrome: A randomized trial.

BACKGROUND: This study aimed to observe the clinical effects of "He Tiao Du Ren An Shen Acupuncture" (HTDRAS Acupuncture) for treating restless leg syndrome (RLS). METHODS: We randomly divided 66 RLS patients into 2 groups: the observation group received "He Tiao Du Ren An Shen Acupuncture" and the control group received conventional acupuncture. All participants were treated once a day, 6 days a week, with 1 day off, for a total of 1 month. Clinical effectiveness of the 2 groups was compared, neurotransmitter levels, the International Restless Leg Syndrome Scale and the Hamilton Anxiety Scale were assessed in both groups. RESULTS: The curative effect in the observation group was better than that in the control group (P < .05). After treatment, the expression of 5-hydroxytryptamine in the observation group was higher than in the control group (P < .05). The International Restless Leg Syndrome Scale and Hamilton Anxiety Scale scores in observation group were lower than those in control group (P < .05). CONCLUSION: "He Tiao Du Ren An Shen Acupuncture" for RLS is significantly effective and safe. It can effectively improve the levels of 5-hydroxytryptamine in RLS patients, alleviate clinical symptoms and reduce anxiety. This treatment has a high clinical application value and is worthy of clinical promotion.

Analysis of geographical origin of solar terms based on the STTMD method.

The 24 solar terms are a significant component of traditional Chinese culture. Amid global warming climate change, research on the Solar Terms has gained increasing prominence. Identifying the geographical origins of the Solar Terms not only provides evidence for studies on the origins of Chinese agricultural civilization but also serves as a critical foundation for the innovative utilization of traditional culture in the modern era. Previous research has primarily relied on historical records, literature review, and field investigation, often challenged by the vast and complex data, the difficulty distinguishing authenticity, the time-consuming nature of the work, and the need for direct scientific evidence. The STTMD (Solar Terms Typical Meteorological Day) method was used for typifying solar term meteorological data sequences, supplemented by isothermal estimation and clustering analysis. This approach was further validated using key crop germplasm sites, phenological indicators, and phenological observation contour maps. The results derived from statistical methods are cross-referenced with historical documents to infer the geographical origins of the 24 Solar Terms. The findings indicate that: (1)On a larger spatial scale, the Solar Terms originated in the middle and lower reaches of the Yellow River; (2)On a smaller spatial scale, the "Luoyang-Zhengzhou-Anyang" triangle is the most probable origin area; (3)The core area of origin is hypothesized to be in present-day Xingyang, Henan Province, or slightly further north. These results are consistent with historical literature and phenological records of crops, offering a novel analysis and transformative insights into the knowledge of Solar Terms. The study provides valuable evidence or methodological inspiration for historical agricultural research in China and offers references for agricultural production and the environmental impacts of global warming.

Accumulated ß-catenin is associated with human atrial fibrosis and atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is associated with increased risk of stroke and mortality. It has been reported that the process of atrial fibrosis was regulated by ß-catenin in rats with AF. However, pathophysiological mechanisms of this process in human with AF remain unclear. This study aims to investigate the possible mechanisms of ß-catenin in participating in the atrial fibrosis using human right atrial appendage (hRAA) tissues . METHODS: We compared the difference of ß-catenin expression in hRAA tissues between the patients with AF and sinus rhythm (SR). The possible function of ß-catenin in the development of AF was also explored in mice and primary cells. RESULTS: Firstly, the space between the membrane of the gap junctions of cardiomyocytes was wider in the AF group. Secondly, the expression of the gap junction function related proteins, Connexin40 and Connexin43, was decreased, while the expression of ß-catenin and its binding partner E-cadherin was increased in hRAA and cardiomyocytes of the AF group. Thirdly, ß-catenin colocalized with E-cadherin on the plasma membrane of cardiomyocytes in the SR group, while they were dissociated and accumulated intracellularly in the AF group. Furthermore, the expression of glycogen synthase kinase 3ß (GSK-3ß) and Adenomatous Polyposis Coli (APC), which participated in the degradation of ß-catenin, was decreased in hRAA tissues and cardiomyocytes of the AF group. Finally, the development of atrial fibrosis and AF were proved to be prevented after inhibiting ß-catenin expression in the AF model mice. CONCLUSIONS: Based on human atrial pathological and molecular analyses, our findings provided evidence that ß-catenin was associated with atrial fibrosis and AF progression.

Whole transcriptome sequencing revealed the gene regulatory network of hypoxic response in yak Sertoli cells.

Yaks live in the Qinghai-Tibet Plateau for a long time where oxygen is scarce, but can ensure the smooth development of testis and spermatogenesis. The key lies in the functional regulation of the Sertoli cells under hypoxia. In this study, we sequenced yak Sertoli cells cultured in normal oxygen concentration (Normoxia) and treated with low oxygen concentration (Hypoxia) by whole transcriptomics, and screened out 194 differentially expressed mRNAs (DEmRNAs), 934 differentially expressed LncRNAs (DELncRNAs) and 129 differentially expressed miRNAs (DEmiRNAs). GO and KEGG analysis showed that these differential genes were mainly concentrated in PI3K-AKT, MAPK, RAS, and other signaling pathways, and were associated with glucose metabolism, tight junction, steroid hormone synthesis, cell fusion, and immunity of yak Sertoli cells. We constructed the gene interaction network of yak Sertoli cells in hypoxia and screened out the relationship pairs related to glucose metabolism and tight junction. The results suggested that the changes in energy metabolism, tight junction, and immune regulation of yak Sertoli cells under hypoxia might provide favorable conditions for spermatogenesis. This study provides data for further study on the role of non-coding RNA in testis development and spermatogenesis of yak.

Monocyte to High-density Lipoprotein Cholesterol Ratio as a Predictor of Nonalcoholic Fatty Liver Disease in Childhood Obesity.

OBJECTIVE: Inflammation is involved in the development and progression of nonalcoholic fatty liver disease (NAFLD). The monocyte to high-density lipoprotein cholesterol ratio (MHR) has emerged as a marker for various inflammation-related diseases. The aim of the present study was to investigate the association between the MHR and NAFLD in a population with childhood obesity. METHODS: Based on hepatic ultrasound, a total of 504 children with obesity (357 with NAFLD and 147 without NAFLD) were included in the study. The correlation between the MHR and NAFLD risk factors was assessed by Pearson's and Spearman's analyses. Multivariate stepwise logistic regression analyses were conducted to explore the association between the MHR and the risk of NAFLD. RESULTS: The MHR in patients with NAFLD was significantly greater than that in patients without NAFLD [0.52 (0.44-0.67) versus 0.44 (0.34-0.57), P<0.001]. Multivariate stepwise logistic regression analysis demonstrated that the MHR [odds ratio (OR): 1.033, 95% confidence interval (CI): 1.015-1.051; P<0.001] was an independent predictor of NAFLD in childhood obesity patients, as were age (OR: 1.205, 95% CI: 1.059-1.371; P=0.005], waist circumference [OR: 1.037, 95% CI: 1.008-1.067; P=0.012], and alanine transaminase [OR: 1.067, 95% CI: 1.045-1.089; P<0.001]. Additionally, MHR quartiles showed a significant positive association with the incidence of NAFLD after adjusting for potential confounding factors. CONCLUSION: The present study showed that the MHR may serve as an available and useful indicator of NAFLD in individuals with childhood obesity.

Retraction: Recent advances in total synthesis of protoberberine and chiral tetrahydroberberine alkaloids.

Retraction of 'Recent advances in total synthesis of protoberberine and chiral tetrahydroberberine alkaloids' by Zhen-Xi Niu et al., Nat. Prod. Rep., 2024, https://doi.org/10.1039/d4np00016a.

Impact of heat treatment on the flavor stability of Longjing green tea beverages: Metabolomic insights and sensory correlations.

The flavor stability of tea beverages during storage has long been a concern. The study aimed to explore the flavor stability of Longjing green tea beverage using accelerated heat treatment trials, addressing the shortage of lengthy storage trials. Sensory evaluations revealed changes in bitterness, umami, overall harmonization, astringency, and ripeness as treatment duration increased. Accompanied by a decrease in L-values, ΔE and an increase in a and b-values. Seventeen non-volatile metabolites and three volatile metabolites were identified differential among samples by metabolomics, with subsequent correlation analysis indicating associations between sensory attributes and specific metabolites. Umami was linked to epigallocatechin 3,5-digallate and alpha-D-glucopyranose, astringency was correlated with ellagic acid and 1-ethyl-1H-pyrrole. Ripeness showed associations with ellagic acid, 6,7-dihydroxycoumarin, heptanal, and benzaldehyde, and overall harmonization was linked to 6,7-dihydroxycoumarin, ß-myrcene, α-terpineol, and heptanal. A series of verification tests confirmed the feasibility of accelerated heat treatment trials to replace traditional storage trials. These results offer valuable insights into unraveling the complex relationship between sensory and chemical profiles of green tea beverages.

Controlled interconversion of macrocyclic atropisomers via defined intermediates.

Macrocyclic conformations play a crucial role in regulating their properties. Our understanding of the determinants to control macrocyclic conformation interconversion is still in its infancy. Here we present a macrocycle, octamethyl cyclo[4](1,3-(4,6)-dimethylbenzene)[4]((4,6-benzene)(1,3-dicarboxylate) (OC-4), that can exist at 298 K as two stable atropisomers with C2v and C4v symmetry denoted as C2v-OC-4 and C4v-OC-4, respectively. Heating induces the efficient stepwise conversion of C2v- to C4v-OC-4 via a Cs-symmetric intermediate (Cs-OC-4). It differs from the typical transition state-mediated processes of simple C-C single bond rotations. Hydrolysis and further esterification with a countercation dependence promote the generation of C2v- and Cs-OC-4 from C4v-OC-4. In contrast to C2v-OC-4, C4v-OC-4 can bind linear guests to form pseudo-rotaxans, or bind C60 or C70 efficiently. The present study highlights the differences in recognition behavior that can result from conformational interconversion, as well as providing insights into the basic parameters that govern coupled molecular rotations.