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1.
Cell Rep ; 43(8): 114511, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39024101

ABSTRACT

Bombesin receptor subtype-3 (BRS3) is an important orphan G protein-coupled receptor that regulates energy homeostasis and insulin secretion. As a member of the bombesin receptor (BnR) family, the lack of known endogenous ligands and high-resolution structure has hindered the understanding of BRS3 signaling and function. We present two cryogenic electron microscopy (cryo-EM) structures of BRS3 in complex with the heterotrimeric Gq protein in its active states: one bound to the pan-BnR agonist BA1 and the other bound to the synthetic BRS3-specific agonist MK-5046. These structures reveal the architecture of the orthosteric ligand pocket underpinning molecular recognition and provide insights into the structural basis for BRS3's selectivity and low affinity for bombesin peptides. Examination of conserved micro-switches suggests a shared activation mechanism among BnRs. Our findings shed light on BRS3's ligand selectivity and signaling mechanisms, paving the way for exploring its therapeutic potential for diabetes, obesity, and related metabolic disorders.

2.
ACS Nano ; 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39013102

ABSTRACT

Mucosal vaccines can prevent viruses from infecting the respiratory mucosa, rather than only curtailing infection and protecting against the development of disease symptoms. The SARS-CoV-2 spike receptor-binding domain (RBD) is a compelling vaccine target but is undermined by suboptimal mucosal immunogenicity. Here, we report a SARS-CoV-2-mimetic extracellular-vesicle vaccine developed using genetic engineering and dendritic cell membrane budding. After mucosal immunization, the vaccine recruits antigen-presenting cells rapidly initiating a strong innate immune response. Notably, it obviates the need for adjuvants and can induce germinal center formation through both intramuscular and intratracheal vaccination. It not only elicits high levels of RBD-specific antibodies but also stimulates extensive cellular immunity in the respiratory mucosa. A sequential immunization strategy, starting with an intramuscular injection followed by an intratracheal booster, significantly bolsters mucosal immunity with high levels of IgA and tissue-resident memory T cell responses, thereby establishing a formidable defense against pseudovirus infection.

3.
Adv Healthc Mater ; : e2401737, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38979864

ABSTRACT

Conjugated polymer dots (Pdots) have shown potential in the biomedical fields due to their optical properties and customizable design. However, the limited research on the biotoxicity of Pdots hinders their further application and translation. Lipophilic Pdots are prone to adsorbing specific proteins, leading to targeted tissue accumulation. Therefore, lipophilic fluorescent Pdots (Bare-Pdots) are synthesized using the conjugated polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) to systematically evaluate their biodistribution and biotoxicity in stem cells, zebrafish embryos, and mice. It is observed that Bare-Pdots are readily internalized by cells and adhered to the embryonic chorion. Additionally, Bare-Pdots exhibit a distinct distribution in brown adipose tissue and heart, closely associated with phagocytosis of capillary endothelial cells involved in lipid metabolism. Notably, injection of Bare-Pdots at 5 mg kg-1 results in dysfunction of brown adipose tissue and an increased risk of obesity 90 days post-injection. Furthermore, hydrophilic COOH-Pdots and NH2-Pdots with reduced lipophilicity are synthesized using amphiphilic ligands. NH2-Pdots show similar distribution but lower biotoxicity compared to Bare-Pdots. Nevertheless, injection of COOH-Pdots at 5 mg kg-1 causes a decrease in white blood cells and renal tubular damage. These findings provide valuable insights for optimizing dosage to ensure the safe use of Pdots in preclinical applications.

4.
Proc Natl Acad Sci U S A ; 121(26): e2321710121, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38885377

ABSTRACT

Somatostatin receptor 5 (SSTR5) is an important G protein-coupled receptor and drug target for neuroendocrine tumors and pituitary disorders. This study presents two high-resolution cryogenicelectron microscope structures of the SSTR5-Gi complexes bound to the cyclic neuropeptide agonists, cortistatin-17 (CST17) and octreotide, with resolutions of 2.7 Å and 2.9 Å, respectively. The structures reveal that binding of these peptides causes rearrangement of a "hydrophobic lock", consisting of residues from transmembrane helices TM3 and TM6. This rearrangement triggers outward movement of TM6, enabling Gαi protein engagement and receptor activation. In addition to hydrophobic interactions, CST17 forms conserved polar contacts similar to somatostatin-14 binding to SSTR2, while further structural and functional analysis shows that extracellular loops differently recognize CST17 and octreotide. These insights elucidate agonist selectivity and activation mechanisms of SSTR5, providing valuable guidance for structure-based drug development targeting this therapeutically relevant receptor.


Subject(s)
Octreotide , Receptors, Somatostatin , Receptors, Somatostatin/metabolism , Receptors, Somatostatin/agonists , Receptors, Somatostatin/chemistry , Humans , Octreotide/chemistry , Octreotide/pharmacology , Octreotide/metabolism , Neuropeptides/metabolism , Neuropeptides/chemistry , Cryoelectron Microscopy , Protein Binding , Peptides, Cyclic/chemistry , Peptides, Cyclic/pharmacology , Peptides, Cyclic/metabolism , Somatostatin/metabolism , Somatostatin/chemistry , Somatostatin/analogs & derivatives , Models, Molecular , HEK293 Cells
6.
Adv Mater ; : e2312812, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38839075

ABSTRACT

High-performance lithium metal anodes are crucial for the development of advanced Li metal batteries. Herein, this work reports a novel plasma coupled electrolyte additive strategy to prepare high-quality composite solid electrolyte interphase (SEI) on Li metal to achieve enhanced performance and stability. With the guidance of calculations, this work selects diethyl dibromomalonate (DB) as an additive to optimize the solvation structure of electrolytes to modify the SEI. Meanwhile, this work groundbreakingly develops DB plasma technology coupled with DB electrolyte additive to construct a combinatorial SEI: inner plasma-induced SEI layer composed of LiBr and Li2CO3 plus additive-reduced SEI containing LiBr/Li2CO3/organic lithium compounds as an outer compatible layer. The optimized hybrid SEI has strong affinity toward Li+ and good mechanical properties, thereby inducing horizontal dispersion and uniform deposition of Li+ and keep structure stable. Accordingly, the symmetrical cells exhibit enhanced cycling stability for 1200 h at an overpotential of 23.8 mV with average coulombic efficiency (99.51%). Additionally, the full cells with LiNi0.8Co0.1Mn0.1O2 cathode deliver a capacity retention of 81.7% after 300 cycles at 0.5 C, and the pouch cell achieves a volumetric specific energy of ≈664 Wh L‒1. This work provides new enlightenment on plasma technology for fabrication of advanced metal anodes for energy storage.

7.
Nat Commun ; 15(1): 4202, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38760354

ABSTRACT

Sulfides are promising electrolyte materials for all-solid-state Li metal batteries due to their high ionic conductivity and machinability. However, compatibility issues at the negative electrode/sulfide electrolyte interface hinder their practical implementation. Despite previous studies have proposed considerable strategies to improve the negative electrode/sulfide electrolyte interfacial stability, industrial-scale engineering solutions remain elusive. Here, we introduce a scalable Li-Al-Cl stratified structure, formed through the strain-activated separating behavior of thermodynamically unfavorable Li/Li9Al4 and Li/LiCl interfaces, to stabilize the negative electrode/sulfide electrolyte interface. In the Li-Al-Cl stratified structure, Li9Al4 and LiCl are enriched at the surface to serve as a robust solid electrolyte interphase and are diluted in bulk by Li metal to construct a skeleton. Enabled by its unique structural characteristic, the Li-Al-Cl stratified structure significantly enhances the stability of negative electrode/sulfide electrolyte interface. This work reports a strain-activated phase separation phenomenon and proposes a practical pathway for negative electrode/sulfide electrolyte interface engineering.

8.
Neural Netw ; 177: 106386, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38776761

ABSTRACT

In scenarios like privacy protection or large-scale data transmission, data-free knowledge distillation (DFKD) methods are proposed to learn Knowledge Distillation (KD) when data is not accessible. They generate pseudo samples by extracting the knowledge from teacher model, and utilize above pseudo samples for KD. The challenge in previous DFKD methods lies in the static nature of their target distributions and they focus on learning the instance-level distributions, causing its reliance on the pretrained teacher model. To address above concerns, our study introduces a novel DFKD approach known as AdaDFKD, designed to establish and utilize relationships among pseudo samples, which is adaptive to the student model, and finally effectively mitigates the aforementioned risk. We achieve this by generating from "easy-to-discriminate" samples to "hard-to-discriminate" samples as human does. We design a relationship refinement module (R2M) to optimize the generation process, wherein we learn a progressive conditional distribution of negative samples and maximize the log-likelihood of inter-sample similarity of pseudosamples. Theoretically, we discover that such design of AdaDFKD both minimize the divergence and maximize the mutual information between the distribution of teacher and student models. Above results demonstrate the superiority of our approach over state-of-the-art (SOTA) DFKD methods across various benchmarks, teacher-student pairs, and evaluation metrics, as well as robustness and fast convergence.


Subject(s)
Knowledge , Humans , Machine Learning , Neural Networks, Computer , Algorithms
9.
Compend Contin Educ Dent ; 45(Suppl 1): 6-9, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38781410

ABSTRACT

The study objective was to evaluate the effect of different interdental oral cleaning modalities on gingivitis and plaque following a 6-week period of home use. This was a randomized, parallel, examiner-blinded study. Study subjects were routine manual toothbrush (MTB) users with moderate to severe gingivitis, aged 18 to 65 years. Subjects were required to have a gingival bleeding score of ≥1 on at least 50 gingival sites per the Gingival Bleeding Index (GBI) and to have a minimum average plaque score of ≥0.6 per the Rustogi Modified Navy Plaque Index (RMNPI) following a 3- to 6-hour plaque accumulation period. Subjects were randomly assigned to one of four groups based on the oral care cleaning modality: (1) NON group: MTB alone, (2) FLS group: MTB plus string floss, (3) MPF group: MTB plus a Philips® Sonicare® Power Flosser with the Quad Stream nozzle, or (4) PPF group: Philips Sonicare power toothbrush plus the power flosser. Safety and efficacy measures (Modified Gingival Index [MGI], GBI, and RMNPI) were assessed at baseline, 2 weeks, and 6 weeks. The primary efficacy endpoint was the reduction in gingival inflammation from baseline to week 6 as measured by the MGI. A total of 260 subjects were randomized and 256 subjects completed the study. The adjusted mean percent reduction in gingival inflammation from baseline to week 6 was 14.90% for the NON group, 13.16% for the FLS group, 33.51% for the MPF group, and 49.30% for the PPF group. Pairwise comparisons indicated that both the PPF and MPF groups were statistically significantly different from both the NON and FLS groups. In conclusion, use of either the Philips Sonicare power toothbrush with the Philips Sonicare Power Flosser or an MTB with the Philips Sonicare Power Flosser was statistically superior to an MTB alone and an MTB used with string floss in reducing gingival inflammation following 6 weeks of home use.


Subject(s)
Dental Devices, Home Care , Dental Plaque , Gingivitis , Periodontal Index , Toothbrushing , Humans , Gingivitis/prevention & control , Middle Aged , Adult , Dental Plaque/prevention & control , Toothbrushing/instrumentation , Male , Female , Aged , Adolescent , Single-Blind Method , Oral Hygiene , Young Adult , Dental Plaque Index
10.
Compend Contin Educ Dent ; 45(Suppl 1): 10-13, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38781411

ABSTRACT

The study objective was to evaluate the effect of two different interdental oral cleaning modalities on gingivitis and plaque following a 4-week period of home use. This was a randomized, parallel, single-blinded study. Subjects were routine manual toothbrush (MTB) users with moderate to severe gingivitis, aged 18 to 65 years. Subjects were required at baseline to have a gingival bleeding score of ≥1 on at least 50 gingival sites per the Gingival Bleeding Index (GBI) and to have an overall plaque score of ≥0.6 per the Rustogi Modified Navy Plaque Index (RMNPI) following a 3- to 6-hour plaque accumulation period. Subjects were randomly assigned to one of three groups based on the oral care cleaning modalities: (1) NON group: MTB alone, (2) IDB group: MTB plus an interdental brush, or (3) MPF group: MTB plus a Philips® Sonicare® Power Flosser with the Quad Stream nozzle. All subjects used the MTB with fluoride toothpaste. Efficacy measures (Modified Gingival Index [MGI], GBI, and RMNPI) and safety were assessed at baseline, 2 weeks, and 4 weeks. The primary efficacy endpoint was the reduction in gingival inflammation from baseline to week 4 as measured by the MGI. A total of 189 subjects were randomized and 186 completed the study. The adjusted mean percent reduction in gingival inflammation from baseline to week 4 was 2.80% for the NON group, 11.32% for the IDB group, and 20.87% for the MPF group. The differences between the MPF group and the NON and IDB groups were statistically significant (.0001). In conclusion, use of the MTB with the Philips Sonicare Power Flosser showed statistically significant benefits compared to an MTB alone and an MTB used with an interdental brush in reducing gingival inflammation following 4 weeks of home use.


Subject(s)
Dental Devices, Home Care , Dental Plaque , Gingivitis , Periodontal Index , Toothbrushing , Humans , Gingivitis/prevention & control , Middle Aged , Adult , Dental Plaque/prevention & control , Single-Blind Method , Toothbrushing/instrumentation , Female , Male , Aged , Adolescent , Dental Plaque Index , Young Adult , Oral Hygiene/instrumentation , Oral Hygiene/methods , Toothpastes/therapeutic use
11.
Zhongguo Yi Liao Qi Xie Za Zhi ; 48(2): 232-236, 2024 Mar 30.
Article in Chinese | MEDLINE | ID: mdl-38605628

ABSTRACT

In order to realize the diagnosis of slit lamp in cross-regional patients and improve the real-time and convenience of diagnosis, a remote slit lamp diagnosis platform based on Internet of Things (IoT) technology is designed. Firstly, the feasibility of remote slit lamp is analyzed. Secondly, the IoT platform architecture of doctor/server/facility (D/S/F) is proposed and a remote slit lamp is designed. Finally, the performance of the remote slit lamp diagnostic platform is tested. The platform solves the communication problem of distributed slit lamps and realizes respectively numerical control of multi-area slit lamp by multi-eye experts. The test results show that the remote control delay of the platform is less than 20 ms, which supports multiple experts to diagnose multiple patients separately.


Subject(s)
Internet of Things , Slit Lamp , Humans , Technology
12.
Shock ; 61(6): 934-941, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38598836

ABSTRACT

ABSTRACT: Background: The high mortality rates of patients who are resuscitated from cardiac arrest (CA) are attributed to post cardiac arrest syndrome (PCAS). This study evaluated the effect of hyperoxygenation and targeted temperature management (TTM) on PCAS in rats with different causes of CA. Methods and Results: One hundred sixty-eight Sprague-Dawley rats were equally divided into asphyxial and dysrhythmic groups. Animals were further randomized into four subgroups immediately after resuscitation: normoxia-normothermia (NO-NT), ventilated with 21% oxygen under normothermia; hyperoxia-normothermia (HO-NT), ventilated with 100% oxygen for 3 hours under normothermia; normoxia-hypothermia (NO-HT), ventilated with 21% oxygen for 3 hours under hypothermia; and hyperoxia-hypothermia (HO-HT), ventilated with 100% oxygen for 3 hours under hypothermia. Post resuscitation cardiac dysfunction, neurological recovery, and pathological analysis were assessed. For asphyxial CA, HO-NT and HO-HT (68.8% and 75.0%) had significantly higher survival than NO-NT and NO-HT (31.3% and 31.3%). For dysrhythmic CA, NO-HT and HO-HT (81.3% and 87.5%) had significantly higher survival than NO-NT and HO-NT (44.0% and 50.0%). When all of the rats were considered, the survival rate was much higher in HO-HT (81.3%). Compared with NO-NT (57.7% ± 14.9% and 40.3% ± 7.8%), the collagen volume fraction and the proportion of fluoro-jade B-positive area in HO-HT (14.0% ± 5.7% and 28.0% ± 13.3%) were significantly reduced. Conclusion: The beneficial effects of hyperoxygenation and TTM are dependent on the cause of arrest: hyperoxygenation benefits asphyxial, whereas TTM benefits dysrhythmic CA. The combination of hyperoxygenation and TTM could effectively improve the functional outcome of PCAS regardless of the cause of CA.


Subject(s)
Hypothermia, Induced , Rats, Sprague-Dawley , Animals , Rats , Hypothermia, Induced/methods , Male , Post-Cardiac Arrest Syndrome/therapy , Cardiopulmonary Resuscitation/methods , Oxygen Inhalation Therapy/methods , Heart Arrest/therapy
13.
J Food Sci ; 89(6): 3816-3828, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38685878

ABSTRACT

Calcium supplementation has been shown to be efficacious in mitigating the progression of senile osteoporosis (SOP) and reducing the incidence of osteoporotic fractures resulting from prolonged calcium shortage. In this study, Grifola frondosa (GF) peptides-calcium chelate were synthesized through the interaction between peptide from GF and CaCl2. The chelation reaction was shown to involve the participation of the amino and carboxyl groups in the peptide, as revealed by scanning electron microscope, Fourier-transform infrared, and ultraviolet spectrophotometry. Furthermore, a mouse model of (SOP) induced by d-galactose was established (SCXK-2018-0004). Results demonstrated that low dosage of low-molecular weight GF peptides-calcium chelates (LLgps-Ca) could significantly improve serum index and pathological features of bone tissue and reduce bone injury. Further research suggested that LLgps-Ca could ameliorate SOP by modulating the disrupted metabolic pathway, which includes focal adhesion, extracellular matrix receptor interaction, and PI3K-Akt signaling pathway. Using Western blot, the differentially expressed proteins were further confirmed. Thus, calciumchelating peptides from GF could serve as functional calcium agents to alleviate SOP.


Subject(s)
Calcium , Disease Models, Animal , Osteoporosis , Peptides , Animals , Mice , Peptides/pharmacology , Calcium/metabolism , Female , Calcium Chelating Agents/pharmacology , Humans
14.
Clin Transl Oncol ; 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38491294

ABSTRACT

Thyroid hormone has been shown to have both tumor-promoting and tumor-suppressing actions, which has led to significant debate over its involvement in the development of cancer. Proliferation, apoptosis, invasiveness, and angiogenesis are all aspects of cancer that are affected by the thyroid hormones T3 and T4, according to research conducted in animal models and in vitro experiments. The effects of thyroid hormones on cancer cells are mediated by many non-genomic mechanisms, one of which involves the activation of the plasma membrane receptor integrin αvß3. Typically, abnormal amounts of thyroid hormones are linked to a higher occurrence of cancer. Both benign and malignant thyroid disorders were found to be associated with an increased risk of extra-thyroidal malignancies, specifically colon, breast, prostate, melanoma, and lung cancers. The purpose of this review was to shed light on this link to define which types of cancer are sensitive to thyroid hormones and, as a result, are anticipated to respond favorably to treatment of the thyroid hormone axis.

15.
Nat Commun ; 15(1): 2552, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38514649

ABSTRACT

Sulfide electrolytes represent a crucial category of superionic conductors for all-solid-state lithium metal batteries. Among sulfide electrolytes, glassy sulfide is highly promising due to its long-range disorder and grain-boundary-free nature. However, the lack of comprehension regarding glass formation chemistry has hindered their progress. Herein, we propose interstitial volume as the decisive factor influencing halogen dopant solubility within a glass matrix. We engineer a Li3PS4-Li4SiS4 complex structure within the sulfide glassy network to facilitate the release of interstitial volume. Consequently, we increase the dissolution capacity of LiI to 40 mol% in 75Li2S-25P2S5 glass. The synthesized glass exhibits one of the highest ionic conductivities among reported glass sulfides. Furthermore, we develop a glassy/crystalline composite electrolyte to mitigate the shortcomings of argyrodite-type sulfides by utilizing our synthesized glass as the filler. The composite electrolytes effectively mitigate Li intrusion. This work unveils a protocol for the dissolution of halogen dopants in glass electrolytes.

16.
BMC Cardiovasc Disord ; 24(1): 123, 2024 Feb 24.
Article in English | MEDLINE | ID: mdl-38402377

ABSTRACT

BACKGROUND: Acute myocardial infarction (AMI) is indeed a significant cause of mortality and morbidity in individuals with coronary heart disease. Ferroptosis, an iron-dependent cell death, is characterized by the accumulation of intracellular lipid peroxides, which is implicated in cardiomyocyte injury. This study aims to identify biomarkers that are indicative of ferroptosis in the context of AMI, and to examine their potential roles in immune infiltration. METHODS: Firstly, the GSE59867 dataset was used to identify differentially expressed ferroptosis-related genes (DE-FRGs) in AMI. We then performed gene ontology (GO) and functional enrichment analysis on these DE-FRGs. Secondly, we analyzed the GSE76591 dataset and used bioinformatic methods to build ceRNA networks. Thirdly, we identified hub genes in protein-protein interaction (PPI) network. After obtaining the key DE-FRGs through the junction of hub genes with ceRNA and least absolute shrinkage and selection operator (LASSO). ImmucellAI was applied to estimate the immune cell infiltration in each sample and examine the relationship between key DE-FRGs and 24 immunocyte subsets. The diagnostic performance of these genes was further evaluated using the receiver operating characteristic (ROC) curve analysis. Ultimately, we identified an immune-related ceRNA regulatory axis linked to ferroptosis in AMI. RESULTS: Among 56 DE-FRGs identified in AMI, 41 of them were integrated into the construction of competitive endogenous RNA (ceRNA) networks. TLR4 and PIK3CA were identified as key DE-FRGs and PIK3CA was confirmed as a diagnostic biomarker for AMI. Moreover, CD4_native cells, nTreg cells, Th2 cells, Th17 cells, central-memory cells, effector-memory cells, and CD8_T cells had higher infiltrates in AMI samples compared to control samples. In contrast, exhausted cells, iTreg cells, and Tfh cells had lower infiltrates in AMI samples. Spearman analysis confirmed the correlation between 24 immune cells and PIK3CA/TLR4. Ultimately, we constructed an immune-related regulatory axis involving XIST and OIP5-AS1/miR-216a/PIK3CA. CONCLUSION: Our comprehensive analysis has identified PIK3CA as a robust and promising biomarker for this condition. Moreover, we have also identified an immune-related regulatory axis involving XIST and OIP5-AS1/miR-216a/PIK3CA, which may play a key role in regulating ferroptosis during AMI progression.


Subject(s)
Ferroptosis , MicroRNAs , Myocardial Infarction , Humans , Ferroptosis/genetics , Toll-Like Receptor 4/genetics , Myocardial Infarction/diagnosis , Myocardial Infarction/genetics , Class I Phosphatidylinositol 3-Kinases , Biomarkers
17.
Genes (Basel) ; 15(1)2024 01 21.
Article in English | MEDLINE | ID: mdl-38275614

ABSTRACT

Bean common mosaic virus (BCMV) was detected on common bean (Phaseolus vulgaris) plants showing wrinkled and/or narrow leaves, curling, shrinking and chlorosis of leaves, dwarfing of plants, and mottled pods in Inner Mongolia and named BCMV-22Huhe. Its genome has a size of 10,062 bp and was deposited in GenBank under the accession number OR778613. It is closely related to BCMV-Az (GenBank accession no. KP903372, in China) in the lineage of AzBMV. A recombination event was detected for BCMV-22Huhe among the 99 BCMV isolates published in the NCBI GenBank database, showing that BCMV-CJ25 (MK069986, found in Mexico) was a potential major parent, and the minor parent is unknown. This work is the first description of the occurrence of BCMV in Inner Mongolia, China.


Subject(s)
Phaseolus , Potyvirus , Plant Diseases/genetics , Potyvirus/genetics , Phaseolus/genetics , China
18.
Nanoscale ; 16(1): 85-96, 2023 Dec 21.
Article in English | MEDLINE | ID: mdl-38050711

ABSTRACT

To improve polishing performance and reduce the environmental pollution of chemical mechanical polishing (CMP) tests, mesoporous shell/core silica abrasives were prepared, and a novel green CMP slurry was developed, including sorbitol, hydrogen peroxide and sodium carbonate. Prior to CMP, fused silica was roughly polished with ceria slurry. Using developed mesoporous abrasives, surface roughness Sa is reduced from 0.347 to 0.253 nm for a scanning area of 200 × 200 µm2, and the material removal rate (MRR) is increased from 70 to 127 nm min-1, compared with traditional solid abrasives. Based on molecular dynamics (MD) simulations, a novel atomic removal model is proposed for mesoporous abrasives through the immediate elastic recovery of atoms. MD simulations suggest that the formation of convex peaks and pits was inhibited by the mesoporous structure, promoting uniform distribution of surface atoms and atomic removal. This is different from a conventional simple increase of polishing times. In addition, more bridge bonds of Si-O-Si and a lower average Si-O bond order are produced in fused silica samples due to their mesoporous structure, contributing to a higher MRR.

19.
Article in English | MEDLINE | ID: mdl-38145977

ABSTRACT

Student well-being is under renewed scrutiny due to escalating academic stress and mental health concerns among young adults. However, in addition to the measures taken by lecturers, universities, and local governments (top-down approaches), we still know little about how students themselves can take the proactive strategy to manage their well-being (bottom-up approaches). The current study addressed this gap by proposing and examining the beneficial role of proactive vitality management (PVM)-a proactive action aimed at managing physical and mental energy based on personal unique needs and conditions-on student psychological well-being. We collected data from 97 college students (36% male, age mean = 21) over four consecutive weeks (308 data observations) and tested a multilevel moderated mediation model. Results showed that weekly PVM was positively related to student weekly goal attainment, which, in turn, enhanced the current week's well-being and the next week's well-being as well. Further, this positive indirect (carryover) effect of PVM through goal attainment on well-being was stronger for those who had a high learning orientation. Our results indicated that PVM can be an effective self-customized strategy to manage college students' weekly well-being. Theoretical and practical implications were discussed.

20.
Sci Total Environ ; 904: 166811, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37673249

ABSTRACT

A novel wastewater treatment plant process was constructed to overcome the challenge of simultaneous nitrate removal and phosphorus (P) recovery. The results revealed that the P and nitrate removal efficiency rose from 39.0 % and 48.4 % to 92.8 % and 93.6 % after 136 days of operation, and the total P content in the biofilm (TPbiofilm) rose from 15.8 mg/g SS to 57.8 mg/g SS. Moreover, the increase of TPbiofilm changed the metabolic mode of denitrifying polyphosphate accumulating organisms (DPAOs), increasing the P concentration of the enriched stream to 172.5 mg/L. Furthermore, the acid/alkaline fermentation led to the rupture of the cell membrane, which released poly-phosphate and ortho-phosphate of cell/EPS in DPAOs and released metal­phosphorus (CaP and MgP). In addition, high-throughput sequencing analysis demonstrated that the relative abundance of DPAOs involved in P storage increased, wherein the abundance of Acinetobacter and Saprospiraceae rose from 8.0 % and 4.1 % to 16.1 % and 14.0 %. What's more, the highest P recovery efficiency (98.3 ± 1.1 %) could be obtained at optimal conditions for struvite precipitation (pH = 7.56 and P: N: Mg = 1.87:3.66:1) through the response surface method (RSM) simulation, and the precipitates test analysis indicated that P recovery from biofilm sludge was potentially operable. This research was of great essentiality for exploring the recovery of P from biofilm sludge.


Subject(s)
Phosphorus , Sewage , Phosphorus/metabolism , Nitrates/metabolism , Denitrification , Anaerobiosis , Bioreactors , Polyphosphates , Biofilms , Waste Disposal, Fluid/methods , Nitrogen
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