Molecular mechanism of color deepening of ready-to-eat shrimp during storage.

Color deepening occurs during storage of ready-to-eat (RTE) shrimps, which seriously affects their marketing cycle. This study investigated the molecular mechanisms of color deterioration in RTE shrimps during accelerated storage, shedding light on the pattern of change in colored products and content. The findings revealed significant occurrences of phenolic oxidation, lipid oxidation, and Maillard browning reactions during accelerated storage. Qualitative and quantitative analyses were conducted on the colored products resulting from these chemical reactions. Multivariate mathematical models were employed to analyze the phenolic oxidation products (2-methylanthraquinone and p-benzoquinone), lipid oxidation products (lipofuscin-like pigments and hydrophobic pyrroles), and Maillard browning products (pyrazines and melanoidins). These products were identified as the main contributors to the deepening of the color of RTE shrimps during storage. The outcomes of this research could enhance our understanding of the color change mechanism in thermally processed marine foods, providing valuable insights for quality maintenance and industrial advancement.

Characterisation of a casein-/whey protein concentrate-Antarctic krill oil emulsion system and improvement of its storage stability.

AIMS: To develop Antarctic krill oil emulsions with casein and whey protein concentrate (WPC) and study their physicochemical properties and storage stability. METHODS: Emulsions were prepared by homogenisation and ultrasonication. The properties of the emulsions were investigated via ultraviolet ray spectroscopy, dynamic light scattering, confocal laser scanning microscope, sodium dodecyl sulphate-polyacrylamide gel electrophoresis, Fourier transform infra-red spectrometer, and fluorescence spectrum. Shelf life was predicted by the Arrhenius model. RESULTS: Casein- and WPC-krill oil emulsions were well formed; the mean particle diameters were less than 128.19 ± 0.64 nm and 158 ± 1.56 nm, the polymer dispersity indices were less than 0.26 ± 0.01 and 0.27 ± 0.01, and the zeta potential were around -46.88 ± 5.02 mV and -33.51 ± 2.68 mV, respectively. Shelf life was predicted to be 32.67 ± 1.55 days and 29.62 ± 0.65 days (40 °C), 27.69 ± 1.15 days and 23.58 ± 0.14 days (50 °C), 24.02 ± 0.15 days and 20.1 ± 0.08 days (60 °C). CONCLUSION: The prepared krill oil emulsions have great potential to become a new krill oil supplement.

Mechanism of color change in Antarctic krill oil during storage.

Antarctic krill oil (AKO) is reddish-orange in color but undergoes changes during storage. To investigate the color deterioration and potential mechanisms involved, the changes in color, endogenous components (astaxanthin, fatty acids, and phospholipids), and reaction products (aldehydes, α-dicarbonyl compounds, and pyrroles) of AKO upon storage were determined. Although the visual color of AKO tended to darken upon storage, the colorimetric analysis and ultraviolet-visible spectrum analysis both indicated a fading in red and yellow due to the oxidative degradation of astaxanthin. During storage of AKO, lipid oxidation led to the formation of carbonyl compounds such as aldehydes and α-dicarbonyls. In addition, phosphatidylethanolamines (PEs) exhibited a faster loss rate than phosphatidylcholines. Moreover, hydrophobic pyrroles, the Maillard-like reaction products associated with primary amine groups in PEs accumulated. Therefore, it is suggested that the Maillard-like reaction between PEs and carbonyl compounds formed by lipid oxidation contributed to color darkening of AKO during storage.

Effects of Edible Organic Acid Soaking on Color, Protein Physicochemical, and Digestion Characteristics of Ready-to-Eat Shrimp upon Processing and Sterilization.

Soft-packed ready-to-eat (RTE) shrimp has gradually become popular with consumers due to its portability and deliciousness. However, the browning caused by high-temperature sterilization is a non-negligible disadvantage affecting sensory quality. RTE shrimp is processed through "boiling + vacuum soft packing + high temperature and pressure sterilization". Ultraviolet-visible (UV) spectroscopy with CIELAB color measurement showed that phytic acid (PA) + lactic acid (LA), PA + citric acid (CA), and PA + LA + CA soaking before cooking alleviated browning, as well as UVabsorbance and the browning index (BI). Meanwhile, UV spectroscopy and fluorescence spectroscopy showed that organic acid soaking reduced the content of carbonyl, dityrosine, disulfide bonds, surface hydrophobicity, and protein solubility, but promoted the content of free sulfhydryl and protein aggregation. However, in vitro digestion simulations showed that organic acid soaking unexpectedly inhibited the degree of hydrolysis and protein digestibility. This study provides the basis for the application of organic acids as color protectors for RTE aquatic muscle product.

Effects of calcium chloride on the gelling and digestive characteristics of myofibrillar protein in Litopenaeus vannamei.

In this study, the effects of CaCl2 (0, 25, 50, 75, and 100 mM) on the gelling and digestive properties of the myofibrillar protein (MP) in Litopenaeus vannamei were investigated. The results showed that increasing CaCl2 concentration led to changes in the tertiary structure of MP. Specifically, compared with the control group, a 64.31 % increase in surface hydrophobicity and a 45.90 % decrease in the sulfhydryl group were observed after 100 mM CaCl2 treatment. Correspondingly, the water holding capacity and strength of the MP gel increased by 24.46 % and 55.99 %, respectively. These changes were positively correlated with the rheological properties, microstructure pore size, and content of non-flowable water. The mechanical properties of MP gel were improved, and the microstructure became more compact with the increase in CaCl2 concentration. Furthermore, the particle size of the digested MP gels decreased in the presence of CaCl2, which improved the digestion characteristics of MP gels.

Outcomes associated to the time to treatment with intravenous tenecteplase for acute ischaemic stroke: subgroup analysis of the TRACE-2 randomised controlled clinical trial.

BACKGROUND: The benefit of intravenous alteplase in acute ischaemic stroke (AIS) is time-dependent. Tenecteplase is non-inferior to alteplase among patients with AIS. We aimed to delineate the association of the stroke onset to treatment time (OTT) with tenecteplase compared with alteplase on therapeutic benefit and clinical risks. METHODS: This is a post hoc analysis of the Tenecteplase Reperfusion therapy in Acute ischaemic Cerebrovascular Events-2 an open-label, randomised, controlled, non-inferior trial. A total of 1430 AIS within 4.5 hours onset at 53 sites in China from 12 June 2021 to 29 May 2022 were randomly assigned (1:1) to receive either tenecteplase 0.25 mg/kg or alteplase 0.9 mg/kg. The primary efficacy outcome was the proportion of participants with a modified Rankin Scale score of 0-1 at 90 days. A post hoc subgroup analysis was conducted with the OTT divided into three intervals (0-90 min, 91-180 min and 181-270 min). The primary safety outcome was symptomatic intracranial haemorrhage within 36 hours post-thrombolytic treatment. RESULTS: Treatment was initiated within 270 min of stroke onset in 1412 patients who were randomly allocated to either tenecteplase (n=707) or alteplase (n=705). The OR of primary efficacy outcome was similar as OTT increased (p=0.84). Adjusted odds of an excellent functional outcome were 0.99 (95% CI 0.37 to 2.67) for 0-90 min, 1.23 (95% CI 0.88 to 1.71) for 91-180 min and 1.21 (95% CI 0.88 to 1.65) for 181-270 min. All were in favour of the tenecteplase group. Meta-analysis of 2949 patients yielded a pooled risk difference of 5.54 (95% CI -0.18 to 11.26; p=0.82) in favour of tenecteplase for more than 180 min and 1.77 (95% CI -2.66 to 6.20; p=0.58) for 0-180 min. CONCLUSIONS: In AIS patients who were treated with either tenecteplase or alteplase within 4.5 hours onset, there was no difference observed in the efficacy and safety between the two groups at the three different OTT time intervals.

Association between drug craving and aggression in Chinese male methamphetamine-dependent patients with and without depressive symptoms.

Depressive symptoms and aggression are common in patients with substance use disorder. Drug craving is one of the main drivers of drug-seeking behavior. This study aimed to explore the relationship between drug craving and aggression in methamphetamine use disorder (MAUD) patients with and without depressive symptoms. Totally, 613 male patients with MAUD were recruited in this study. Patients with depressive symptoms were identified by the 13-item Beck Depression Inventory (BDI-13). Drug craving and aggression were assessed by the Desires for Drug Questionnaire (DDQ) and the Buss & Perry Aggression Questionnaire (BPAQ), respectively. 374 patients (61.01%) were confirmed to meet the criteria of depressive symptoms. Patients with depressive symptoms had significantly higher DDQ and BPAQ total scores than those without depressive symptoms. DDQ desire and intention were positively correlated with verbal aggression and hostility in patients with depressive symptoms, whereas they were correlated with self-directed aggression in patients without depressive symptoms. In patients with depressive symptoms, DDQ negative reinforcement and a history of suicide attempts were independently associated with BPAQ total score. Our study suggests that male MAUD patients have a high incidence of depressive symptoms and that patients with depressive symptoms may have greater drug cravings and aggression. Depressive symptoms may play a role in the association between drug craving and aggression in patients with MAUD.

Dual regulations on texture and water mobility of shrimp surimi gel with sustained-release epigallocatechin-3-gallate in γ-cyclodextrin metal organic frameworks: Insights into functionality and mechanisms.

Epigallocatechin-3-gallate (EGCG) could demonstrate crosslinking effects on myofibrillar proteins, yet its proneness to self-aggregation could bring excessive crosslinking and water loss within gels, hindering its application as an additive during thermal gelation process. Here, encapsulation with the γ-cyclodextrin metal organic framework (γ-CD-MOF) before the use of EGCG was found to play a dual role: alleviating over-crosslinking of proteins and elevating water retention within gels. Results showed that EGCG got a sustainable release throughout the thermal process due to the gradual fracture of O-K coordinate bounds and structural collapse of γ-CD-MOF. Mechanism insights revealed that the use of EGCG loaded γ-CD-MOF (EGCG@γ-CD-MOF) could regulate formation efficiency on disulfide bounds and promote protonation transition of the amino groups in proteins. Moreover, EGCG@γ-CD-MOF brought a higher retention of phenols within gels through preventing oxidative transformation of phenols towards quinones, which were verified to display a higher affinity towards myosin via molecular calculations.

Characterization of Oyster Protein Hydrolysate-Iron Complexes and their In Vivo Protective Effects against Iron Deficiency-Induced Symptoms in Mice.

Iron is one of the trace mineral elements, and iron deficiency is a common phenomenon that negatively influences human health. Food-derived iron supplements were considered excellent candidates for improving this syndrome. In this work, oyster-protein hydrolysates (OPH) and ferrous chloride successfully formed the OPH-Fe complex (6 mg/mL, 40 °C, 30 min), where the main binding sites involved were the carboxyl and amino groups. The OPH-Fe complex showed no obvious changes in the secondary structure, while the iron changed the morphological appearance and also showed fluorescence quenching, an ultraviolet shift, and an increase in size distribution. The OPH-Fe complex showed better dynamic absorption of iron (64.11 µmol/L) than ferrous sulfate (46.90 µmol/L), and the medium dose had better protective effects against iron-deficiency anemia in vivo. Three representative peptides (DGKGKIPEE, FAGDDAPRA, and VLDSGDGVTH) that were absorbed intact were identified. This experiment provided a theoretical foundation for further study of the digestion and absorption of the OPH-Fe complex.

Encapsulation Alleviates the Auto-browning of Epigallocatechin-3-gallate in Aqueous Solutions through Regulating Molecular Self-Aggregation Behavior.

Catechins are widely recognized for superb antioxidant capability, but their application as food antioxidants is hindered by susceptibility to auto-browning under high-moisture conditions. Here, we proposed a strategy of ordered encapsulation with cyclodextrin-based metal-organic frameworks (CD-MOFs) to alleviate the auto-browning phenomenon of catechins while preserving their antioxidant capability and demonstrated the feasibility of this strategy via selecting epigallocatechin-3-gallate (EGCG) as a model. Even in aqueous solutions, EGCG@CD-MOFs still possessed delayed browning, in contrast with pristine EGCG, characterized by suppressed efficiencies on the generation of oxidative dimers (theasinensin A) and semiquinone radicals. Mechanism insights revealed that ordered encapsulation brought dual regulations on the self-aggregation behavior of EGCG: EGCG@CD-MOFs exhibited a gradual structural collapse from the framework toward irregular aggregates as O-K bonds broke progressively, which restricted molecular mobility of EGCG, and EGCG molecular conformations became constrained by the structure of EGCG@CD-MOFs as well as rich intermolecular forces, even after structural collapse.

The Effect of Heat Treatment on the Digestion and Absorption Properties of Protein in Sea Cucumber Body Wall.

This study was designed, for the first time, to investigate the effect of oxidation on the digestion and absorption properties of protein in boiled sea cucumber body wall (BSCBW) via simulated digestion combined with everted-rat-gut-sac models. Boiling heat treatments led to protein oxidation in SCBW, manifested by increases in free radical intensity, thiobarbituric acid reactive substances, carbonyl groups, disulfide bonds, dityrosine bonds, advanced glycation end products, protein hydrophobicity and aggregation, and declines in both free sulfhydryl groups and secondary structure transition from α-helix to ß-sheet. Boiling for 2 h caused anti-digestion collagen unfolding, provided the action site for protease and improved protein digestion and absorption levels. On the contrary, excessive oxidative modification of 4 h BSCBW resulted in decreased protein digestion and absorption levels. From the perspective of texture, digestion and absorption properties, boiling for 2 h can obtain sea cucumber products with better edible and digestible properties, which is considered to be a better processing condition.

Association between rumination and drug craving in Chinese male methamphetamine use disorder patients with childhood trauma.

BACKGROUND: In China, males make up the majority of methamphetamine (MA) dependent individuals and the majority of treatment seekers. Childhood trauma (CT) and rumination are associated with an increased risk of MA use. However, the association between CT, rumination, and drug craving remains largely unknown. OBJECTIVE: The present study aims to explore the association between rumination and drug craving in methamphetamine use disorder (MAUD) patients with CT. PARTICIPANTS AND SETTING: This study recruited 404 male participants with MAUD from a male drug rehabilitation center in Southwest China. METHODS: Patients with CT were identified by the short form of Childhood Trauma Questionnaire (CTQ-SF). Rumination and drug craving were assessed by the Ruminative Responses Scale (RRS) and the Obsessive Compulsive Drug Use Scale (OCDUS), respectively. RESULTS: 188 patients (46.5 %) experienced CT. Patients who had experienced CT showed significantly higher RRS symptom rumination score and OCDUS total score than those who had not. In patients with CT, RRS total and all subscale scores were positively associated with OCDUS interference of drug. Furthermore, the RRS brooding (ß = 0.34, p < 0.001) and total scores (ß = 0.38, p < 0.001) were determined to be separate contributors to the OCDUS total score in patients with CT. CONCLUSIONS: Our study suggests that CT is common in male MAUD patients, and those who have suffered CT may exhibit higher levels of rumination and drug craving. Moreover, CT may play an influential role in the association between rumination and drug craving in patients with MAUD.

The Association between Emergency Department Length of Stay and In-Hospital Mortality in Older Patients Using Machine Learning: An Observational Cohort Study.

The association between emergency department (ED) length of stay (EDLOS) with in-hospital mortality (IHM) in older patients remains unclear. This retrospective study aims to delineate the relationship between EDLOS and IHM in elderly patients. From the ED patients (n = 383,586) who visited an urban academic tertiary care medical center from January 2010 to December 2016, 78,478 older patients (age ≥60 years) were identified and stratified into three age subgroups: 60-74 (early elderly), 75-89 (late elderly), and ≥90 years (longevous elderly). We applied multiple machine learning approaches to identify the risk correlation trends between EDLOS and IHM, as well as boarding time (BT) and IHM. The incidence of IHM increased with age: 60-74 (2.7%), 75-89 (4.5%), and ≥90 years (6.3%). The best area under the receiver operating characteristic curve was obtained by Light Gradient Boosting Machine model for age groups 60-74, 75-89, and ≥90 years, which were 0.892 (95% CI, 0.870-0.916), 0.886 (95% CI, 0.861-0.911), and 0.838 (95% CI, 0.782-0.887), respectively. Our study showed that EDLOS and BT were statistically correlated with IHM (p < 0.001), and a significantly higher risk of IHM was found in low EDLOS and high BT. The flagged rate of quality assurance issues was higher in lower EDLOS ≤1 h (9.96%) vs. higher EDLOS 7 h

Age of Onset Moderates the Association between Total Antioxidant Capacity and Cognitive Deficits in Patients with Drug-Naïve Schizophrenia.

Schizophrenia patients with an earlier age of onset have been found to have more serious negative symptoms and cognitive deficits. Oxidative stress is thought to be implicated in cognitive impairment in schizophrenia. Total antioxidant capacity (TAOC) is an essential indicator of oxidative stress. However, the association between age of onset, TAOC, and cognitive performance in schizophrenia remains unexplored. In this study, 201 patients (age: 26.5 ± 9.6 years; male: 53.2%) with drug-naïve schizophrenia were recruited. Clinical symptoms were evaluated using the Positive and Negative Syndrome Scale (PANSS). Cognitive functioning was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Plasma TAOC levels were analyzed using established procedures. Results showed that early-onset (EO) patients had higher TAOC levels, more severe negative symptoms and performed worse on visuospatial/constructional, language and RBANS total scores than non-EO patients. After Bonferroni correction, only non-EO patients showed a significant inverse relationship between TAOC levels and RBANS language, attention, and total scores. Our findings suggest that an early/late age of onset may be correlated with psychopathological symptoms, cognitive impairment and oxidative responses in schizophrenia. Furthermore, the age of onset may moderate the relationship between TAOC and cognitive function in patients with schizophrenia. These findings suggest that improving oxidative stress status in non-EO schizophrenia patients may enhance their cognitive function.

Cancer cell genotype associated tumor immune microenvironment exhibits differential response to therapeutic STING pathway activation in high-grade serous ovarian cancer.

BACKGROUND: High-grade serous ovarian carcinoma (HGSC) is the most lethal gynecologic malignancy characterized by resistance to chemotherapy and high rates of recurrence. HGSC tumors display a high prevalence of tumor suppressor gene loss. Given the type 1 interferon regulatory function of BRCA1 and PTENgenes and their associated contrasting T-cell infiltrated and non-infiltrated tumor immune microenvironment (TIME) states, respectively, in this study we investigated the potential of stimulator of interferon genes (STING) pathway activation in improving overall survival via enhancing chemotherapy response, specifically in tumors with PTEN deficiency. METHODS: Expression of PTEN protein was evaluated in tissue microarrays generated using pretreatment tumors collected from a cohort of 110 patients with HGSC. Multiplex immunofluorescence staining was performed to determine spatial profiles and density of selected lymphoid and myeloid cells. In vivo studies using the syngeneic murine HGSC cell lines, ID8-Trp53 -/-; Pten -/- and ID8-Trp53 -/-; Brca1 -/-, were conducted to characterize the TIME and response to carboplatin chemotherapy in combination with exogenous STING activation therapy. RESULTS: Patient tumors with absence of PTEN protein exhibited a significantly decreased disease specific survival and intraepithelial CD68+ macrophage infiltration as compared with intact PTEN expression. In vivo studies demonstrated that Pten-deficient ovarian cancer cells establish an immunosuppressed TIME characterized by increased proportions of M2-like macrophages, GR1+MDSCs in the ascites, and reduced effector CD8+ cytotoxic T-cell function compared with Brca1-deficient cells; further, tumors from mice injected with Pten-deficient ID8 cells exhibited an aggressive behavior due to suppressive macrophage dominance in the malignant ascites. In combination with chemotherapy, exogenous STING activation resulted in longer overall survival in mice injected with Pten-deficient ID8 cells, reprogrammed intraperitoneal M2-like macrophages derived from Pten-deficient ascites to M1-like phenotype and rescued CD8+ cytotoxic T-cell activation. CONCLUSIONS: This study reveals the importance of considering the influence of cancer cell intrinsic genetic alterations on the TIME for therapeutic selection. We establish the rationale for the optimal incorporation of interferon activating therapies as a novel combination strategy in PTEN-deficient HGSC.

Achieving dual functions of texture modification and water retention of shrimp surimi products with the combination of epigallocatechin-3-gallate and γ-cyclodextrin.

Epigallocatechin-3-gallate (EGCG) exhibits excellent cross-linking effects of myofibrillar proteins, it is prone to self-aggregation, causing excessive cross-linking and moisture loss of gels, which limits its application as a food additive in surimi products. Here, through combination γ-cyclodextrin and EGCG into one inclusion complex, we achieved proper usage of EGCG in shrimp surimi products: elevating both water holding capability and texture properties (hardness, chewiness and resilience). Moreover, the mechanism behind excellent performance was elucidated: as texture modifiers, the complexes improved gel network integrity through intermolecular interactions and moderated disulfide bonds; and as water retainer agents, the complexes promoted transformation of nitrogen in proteins towards the form of protonated amino, facilitating the occurrence of hydration. Furthermore, the inclusion complexes brought a higher phenolic retention within products in contrast with direct addition of EGCG. This work may propose novel insights for the usage of polyphenols as additives in surimi-based products.

Prediction differences and implications of acute kidney injury with and without urine output criteria in adult critically ill patients.

BACKGROUND: Due to the convenience of serum creatinine (SCr) monitoring and the relative complexity of urine output (UO) monitoring, most studies have predicted acute kidney injury (AKI) only based on SCr criteria. This study aimed to compare the differences between SCr alone and combined UO criteria in predicting AKI. METHODS: We applied machine learning methods to evaluate the performance of 13 prediction models composed of different feature categories on 16 risk assessment tasks (half used only SCr criteria, half used both SCr and UO criteria). The area under receiver operator characteristic curve (AUROC), the area under precision recall curve (AUPRC) and calibration were used to assess the prediction performance. RESULTS: In the first week after ICU admission, the prevalence of any AKI was 29% under SCr criteria alone and increased to 60% when the UO criteria was combined. Adding UO to SCr criteria can significantly identify more AKI patients. The predictive importance of feature types with and without UO was different. Using only laboratory data maintained similar predictive performance to the full feature model under only SCr criteria [e.g. for AKI within the 48-h time window after 1 day of ICU admission, AUROC (95% confidence interval) 0.83 (0.82, 0.84) vs 0.84 (0.83, 0.85)], but it was not sufficient when the UO was added [corresponding AUROC (95% confidence interval) 0.75 (0.74, 0.76) vs 0.84 (0.83, 0.85)]. CONCLUSIONS: This study found that SCr and UO measures should not be regarded as equivalent criteria for AKI staging, and emphasizes the importance and necessity of UO criteria in AKI risk assessment.

Effects of Non-Enzymatic Browning and Lipid Oxidation on Color of Ready-to-Eat Abalone during Accelerated Storage and Its Control.

The deepening of color of ready-to-eat (RTE) abalone during storage leads to sensory quality degradation, which seriously affects the shelf life of products and consumers' purchasing desire. The goal of this study is to look into the causes of non-enzymatic browning and lipid oxidation, as well as how to control them, and their effect on the color of RTE abalone during storage. The control, bloodletting and antioxidants groups (lactic acid, citric acid and 4-hexylresorcinol) of RTE abalone were stored for 0, 20 and 40 days at 40 °C, respectively, to explore the rule and mechanism of the color change in RTE abalone. This research shows that RTE abalone undergoes browning during storage. Meanwhile, the content of reducing sugar, phenols and unsaturated fatty acids decreases, while the formation of lipid hydroperoxides and aldehydes increases during storage. In addition, the color change in RTE abalone during storage is mainly related to the Maillard reaction, while the lipid oxidation mainly forms pyrrole and participates in the Strecker degradation process as part of the Maillard reaction. The quality of RTE abalone can be maintained by controlling browning effectively as well as lipid oxidation through bloodletting and the addition of antioxidants to ensure that RTE abalone has high storage stability. According to our research, bloodletting and the addition of antioxidants to RTE abalone have a good application prospect and popularizing value in the storage of RTE abalone.

Near-Infrared Photoluminescence from Ytterbium- and Erbium-Codoped CsPbCl3 Perovskite Quantum Dots with Negative Thermal Quenching.

Near-infrared (NIR) luminescent phosphors hold promise for a wide range of applications, from bioimaging to light-emitting diodes (LEDs), but are typically confined to wavelengths <1300 nm and manifest substantial thermal quenching pervasive in luminescent materials. Here we observed the thermally enhanced NIR luminescence of Er3+ (1540 nm), a 2.5-fold enhancement with increasing temperature from 298 to 356 K, from Yb3+- and Er3+-codoped CsPbCl3 perovskite quantum dots (PQDs) (photoexcited at ∼365 nm). Mechanistic investigations revealed that thermally enhanced phenomena originated from combined effects of thermally stable cascade energy transfer (from a photoexcited exciton to a pair of Yb3+ and then to surrounding Er3+) and minimized quenching of surface-adsorbed water molecules on the 4I13/2 state of Er3+ induced by the temperature increase. Importantly, these PQDs enable producing phosphor-converted LEDs emitting at 1540 nm with inherited thermally enhanced properties, having implications for a wide range of photonic applications.

Free-Standing Carbon Nanofiber Composite Networks Derived from Bacterial Cellulose and Polypyrrole for Ultrastable Potassium-Ion Batteries.

Carbon materials derived from bacterial cellulose have been studied in lithium-ion batteries due to their low cost and flexible characteristics. However, they still face many intractable problems such as low specific capacity and poor electrical conductivity. Herein, bacterial cellulose is used as the carrier and skeleton to creatively realize the composite of polypyrrole on its nanofiber surface. After carbonization treatment, three-dimensional carbon network composites with a porous structure and short-range ordered carbon are obtained for potassium-ion batteries. The introduction of nitrogen doping from polypyrrole can increase the electrical conductivity of carbon composites and provide abundant active sites, improving the comprehensive performance of anode materials. The carbonized bacterial cellulose@polypyrrole (C-BC@PPy) anode exhibits a high capacity of 248 mA h g-1 after 100 cycles at 50 mA g-1 and a capacity retention of 176 mA h g-1 even over 2000 cycles at 500 mA g-1. Combined with density functional theory calculations, these results indicate that the capacity of C-BC@PPy is contributed by N-doped and defect carbon composite materials as well as pseudocapacitance. This study provides a guideline for the development of novel bacterial cellulose composites in the energy storage field.