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1.
Article in English | MEDLINE | ID: mdl-38829762

ABSTRACT

Human-oriented image communication should take the quality of experience (QoE) as an optimization goal, which requires effective image perceptual quality metrics. However, traditional user-based assessment metrics are limited by the deviation caused by human high-level cognitive activities. To tackle this issue, in this paper, we construct a brain response-based image perceptual quality metric and develop a brain-inspired network to assess the image perceptual quality based on it. Our method aims to establish the relationship between image quality changes and underlying brain responses in image compression scenarios using the electroencephalography (EEG) approach. We first establish EEG datasets by collecting the corresponding EEG signals when subjects watch distorted images. Then, we design a measurement model to extract EEG features that reflect human perception to establish a new image perceptual quality metric: EEG perceptual score (EPS). To use this metric in practical scenarios, we embed the brain perception process into a prediction model to generate the EPS directly from the input images. Experimental results show that our proposed measurement model and prediction model can achieve better performance. The proposed brain response-based image perceptual quality metric can measure the human brain's perceptual state more accurately, thus performing a better assessment of image perceptual quality.

2.
Article in English | MEDLINE | ID: mdl-38824095

ABSTRACT

BACKGROUND: In patients with hilar cholangiocarcinoma (HCCA), radical resection can be achieved by resection and reconstruction of the vasculature. However, whether vascular reconstruction (VR) improves long-term and short-term prognosis has not been demonstrated comprehensively. METHODS: This was a retrospective multicenter study of patients who received surgery for HCCA with or without VR. Variables associated with overall survival (OS) and recurrence-free survival (RFS) were identified based on Cox regression. Kaplan-Meier curves were used to explore the impact of VR. Restricted mean survival time (RMST) was used for comparisons of short-term survival between the groups. Patients' intraoperative and postoperative characteristics were compared. RESULTS: Totally 447 patients were enrolled. We divided these patients into 3 groups: VR with radical resections (n = 84); non-VR radical resections (n = 309) and non-radical resection (we pooled VR-nonradical and non-VR nonradical together, n = 54). Cox regression revealed that carbohydrate antigen 242 (CA242), vascular invasion, lymph node metastasis and poor differentiation were independent risk factors for OS and RFS. There was no significant difference of RMST between the VR and non-VR radical groups within 12 months after surgery (10.18 vs. 10.76 mon, P = 0.179), although the 5-year OS (P < 0.001) and RFS (P < 0.001) were worse in the VR radical group. The incidences of most complications were not significantly different, but those of bile leakage (P < 0.001) and postoperative infection (P = 0.009) were higher in the VR radical group than in the non-VR radical group. Additionally, the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) up to 7 days after surgery tended to decrease in all groups. There was no significant difference in the incidence of postoperative liver failure between the VR and non-VR radical groups. CONCLUSIONS: Radical resection can be achieved with VR to improve the survival rate without worsening short-term survival compared with resection with non-VR. After adequate assessment of the patient's general condition, VR can be considered in the resection.

3.
Int J Biol Macromol ; 274(Pt 1): 133243, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38901507

ABSTRACT

To enhance the DNA/RNA amplification efficiency and inhibitor tolerance of Bst DNA polymerase, four chimeric Bst DNA polymerase by fusing with a DNA-binding protein Sto7d and/or a highly hydrophobic protein Hp47 to Bst DNA polymerase large fragment. One of chimeric protein HpStBL exhibited highest inhibitor tolerance, which retained high active under 0.1 U/µL sodium heparin, 0.8 ng/µL humic acid, 2.5× SYBR Green I, 8 % (v/v) whole blood, 20 % (v/v) tissue, and 2.5 % (v/v) stool. Meanwhile, HpStBL showed highest sensitivity (93.75 %) to crude whole blood infected with the African swine fever virus. Moreover, HpStBL showed excellent reverse transcriptase activity in reverse transcription loop-mediated isothermal amplification, which could successfully detect 0.5 pg/µL severe acute respiratory syndrome coronavirus 2 RNA in the presence of 1 % (v/v) stools. The fusion of two domains with different functions to Bst DNA polymerase would be an effective strategy to improve Bst DNA polymerase performance in direct loop-mediated isothermal amplification and reverse transcription loop-mediated isothermal amplification detection, and HpStBL would be a promising DNA polymerase for direct African swine fever virus/severe acute respiratory syndrome coronavirus 2 detection due to simultaneously increased inhibitor tolerance and reverse transcriptase activity.

4.
Sensors (Basel) ; 24(10)2024 May 13.
Article in English | MEDLINE | ID: mdl-38793940

ABSTRACT

Mobile visible light communication (VLC) is key for integrating lighting and communication applications in the 6G era, yet there exists a notable gap in experimental research on mobile VLC. In this study, we introduce a mobile VLC system and investigate the impact of mobility speed on communication performance. Leveraging a laser-based light transmitter with a wide coverage, we enable a light fidelity (LiFi) system with a mobile receiving end. The system is capable of supporting distances from 1 m to 4 m without a lens and could maintain a transmission rate of 500 Mbps. The transmission is stable at distances of 1 m and 2 m, but an increase in distance and speed introduces interference to the system, leading to a rise in the Bit Error Rate (BER). The mobile VLC experimental system provides a viable solution to the issue of mobile access in the integration of lighting and communication applications, establishing a solid practical foundation for future research.

5.
Opt Lett ; 49(10): 2805-2808, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38748166

ABSTRACT

The advancement demands of high-speed wireless data link ask for higher requirements on visible light communication (VLC), where wide coverage stands as a critical criterion. Here, we present the design and implementation of a transmitter structure capable of emitting a high-power wide-coverage white light laser. This laser source exhibits excellent stability, with an irradiation range extending to a half-angle of 20°. Its high brightness satisfies the needs of indoor illumination while maintaining excellent communication performance. Utilizing bit-loading discrete multi-tone modulation, a peak data transmission rate of 3.24 Gbps has been achieved, spanning 1 to 5 m. Remarkably, the data rates exceed 2.5 Gbps within a 40° range at a distance of 5 m, enabling a long-distance, wide coverage, high-speed VLC link for future mobile network applications.

6.
Sensors (Basel) ; 24(8)2024 Apr 13.
Article in English | MEDLINE | ID: mdl-38676116

ABSTRACT

A novel multistatic integrated sensing and communication (ISAC) system based on macro-micro cooperation for the sixth-generation (6G) mobile network is proposed. Instead of using macrosites at both the transmitter and receiver sides, microsites are considered as receivers in cooperative sensing. This system is important since microsites can be deployed more flexibly to reduce their distances to the sensing objects, providing better coverage for sensing service. In this work, we first analyze the deployment problem of microsites, which can be deployed along the radius and azimuth angle to cover macrosite cells. The coverage area of each microsite is derived in terms of its position in the cell. Then, we describe an efficient estimating approach for obtaining the position and velocity of sensing objects in the macrosite cell. By choosing multiple microsites around the targeted sensing area, joint data processing with an efficient optimization method is also provided. Simulation results show that the multistatic ISAC system employing macro-micro cooperation can improve the position and velocity estimation accuracy of objects compared to systems employing macrosite cooperation alone, demonstrating the effectiveness and potential for implementing the proposed system in the 6G mobile network.

7.
Curr Med Chem ; 2024 02 12.
Article in English | MEDLINE | ID: mdl-38347785

ABSTRACT

BACKGROUND: Background: Chemotherapy resistance is one of the main causes of clinical chemotherapy failure. Current cancer research explores the drug resistance mechanism and new therapeutic targets. This work aims to elucidate the mechanism of thyroid hormone receptor interactor 13 (TRIP13) affecting doxorubicin (DOX) resistance in colorectal cancer (CRC). METHODS: Bioinformatics analyses were employed to clarify TRIP13 expression in CRC tissues and predict the correlation of the TRIP13 enrichment pathway with glycolysis-related genes and stemness index mRNAsi. Quantitative real-time polymerase chain reaction and western blot were adopted to analyze the expression of TRIP13 and glycolysis-related genes. Cell Counting Kit-8 was utilized to determine the cell viability and IC50 value. Western blot was employed to measure the expression of stemness-related factors. Cell function assays were performed to detect cells' sphere-forming ability and glycolysis level. Animal models were constructed to determine the effects of TRIP13 expression on CRC tumor growth. RESULTS: TRIP13 was significantly overexpressed in CRC, concentrated in the glycolysis signaling pathway, and positively correlated with stemness index mRNAsi. High expression of TRIP13 facilitated DOX resistance in CRC. Further mechanistic studies revealed that overexpression of TRIP13 could promote cell stemness through glycolysis, which was also confirmed in animal experiments. CONCLUSION: TRIP13 was highly expressed in CRC, which enhanced the DOX resistance of CRC cells by activating glycolysis to promote cell stemness. These findings offer new insights into the pathogenesis of DOX resistance in CRC and suggest that TRIP13 may be a new target for reversing DOX resistance in CRC.

8.
Death Stud ; 48(1): 54-63, 2024.
Article in English | MEDLINE | ID: mdl-36906512

ABSTRACT

Crisis helplines provide important support for vulnerable individuals during the COVID-19 pandemic, which may also impact the helplines. We explored the challenges that the pandemic brought to Taiwan's national suicide prevention hotline and the hotline's responses. We interviewed 14 hotline workers and conducted data analysis using the framework method. The pandemic posed two new challenges to the hotline: potential service interruption and the adjustment of perceived role among hotline workers. The hotline's well-formulated response plan helped it sustain its services during the pandemic, although the workers also experienced stress and frustration resulted from role ambiguity. Our data highlighted the hotline workers' need for accurate COVID-19 information, relevant training, and timely support.


Subject(s)
COVID-19 , Humans , Hotlines , Suicide Prevention , Pandemics
9.
Chronic Dis Transl Med ; 9(4): 345-348, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37915389

ABSTRACT

(A) Immunofluorescence staining showed moderate immunoglobulin A depositions in the mesangial areas (++) of glomeruli (Bars = 100 µm). (B) Segmentally mild mesangial proliferation and mesangial matrix expansion (arrowhead) with mild thickening of glomerular capillary walls (PAS, ×400).

10.
Nano Lett ; 23(19): 9087-9095, 2023 Oct 11.
Article in English | MEDLINE | ID: mdl-37747850

ABSTRACT

Designing bifunctional catalysts with high current densities under industrial circumstances is crucial to propelling hydrogen energy with a boost from fundamental to practical application. In this work, heterojunction nanowire arrays consisting of manganese oxide and cobalt phosphide (denoted as MnO-CoP/NF) are designed to meet the industrial demand by regulating the synergic mass transport and electronic structure coupling with numerous nano-heterogeneous interfaces. The optimal MnO-CoP/NF electrode exhibits remarkable bifunctional electrocatalytic performance with overpotentials of 259.5 mV for hydrogen evolution at a large current density of 1000 mA cm-2 and 392.2 mV for oxygen evolution at 1500 mA cm-2. Moreover, the MnO-CoP/NF electrode demonstrates superior durability and an ultralow voltage of 1.76 V at 500 mA cm-2, outperforming that of a commercial RuO2||Pt/C electrode. This work sheds light on the design of metallic heterostructures with optimized interfacial electronic structures and a high abundance of active sites for practical industrial water splitting applications.

11.
Orphanet J Rare Dis ; 18(1): 250, 2023 08 29.
Article in English | MEDLINE | ID: mdl-37644569

ABSTRACT

BACKGROUND: Townes-Brocks syndrome is a rare autosomal dominant genetic syndrome caused by mutations in SALL1. The clinical features of Townes-Brocks syndrome are highly heterogonous. Identification of new SALL1 mutations and study of the relation between SALL1 mutations and clinical features can facilitate diagnosis of Townes-Brocks syndrome. METHODS: We collected clinical data and blood samples of the two patients and their family members for whole-exome sequencing and Sanger sequencing. Prediction analysis of the SALL1variation protein structure was achieved using Alphafold. The clinical materials and gene sequencing results were analyzed. The clinical materials and gene sequencing results were analyzed. The related literature of Townes-Brocks syndrome were searched and the genotype-renal phenotype analysis was performed combined with this two cases. RESULTS: Based on the clinical features and gene sequencing results, the two patients were diagnosed as Townes-Brocks syndrome. Two novel SALL1 mutations (c.878-887del and c.1240G > T) were identified, both of which were pathogenic mutations. The correlation between genotypes and renal phenotypes in Townes-Brocks syndrome patients caused by SALL1 mutation were summarized. CONCLUSION: This study identified two novel mutations and provided new insights into the correlation of genotypes and renal phenotypes of Townes-Brocks syndrome.


Subject(s)
Arthrogryposis , East Asian People , Humans , Asian People , Mutation/genetics
12.
J Biol Chem ; 299(9): 105158, 2023 09.
Article in English | MEDLINE | ID: mdl-37579949

ABSTRACT

Mutations in the gene encoding polycystin-1 (PC1) are the most common cause of autosomal dominant polycystic kidney disease (ADPKD). Cysts in ADPKD exhibit a Warburg-like metabolism characterized by dysfunctional mitochondria and aerobic glycolysis. PC1 is an integral membrane protein with a large extracellular domain, a short C-terminal cytoplasmic tail and shares structural and functional similarities with G protein-coupled receptors. Its exact function remains unclear. The C-terminal cytoplasmic tail of PC1 undergoes proteolytic cleavage, generating soluble fragments that are overexpressed in ADPKD kidneys. The regulation, localization, and function of these fragments is poorly understood. Here, we show that a ∼30 kDa cleavage fragment (PC1-p30), comprising the entire C-terminal tail, undergoes rapid proteasomal degradation by a mechanism involving the von Hippel-Lindau tumor suppressor protein. PC1-p30 is stabilized by reactive oxygen species, and the subcellular localization is regulated by reactive oxygen species in a dose-dependent manner. We found that a second, ∼15 kDa fragment (PC1-p15), is generated by caspase cleavage at a conserved site (Asp-4195) on the PC1 C-terminal tail. PC1-p15 is not subject to degradation and constitutively localizes to the mitochondrial matrix. Both cleavage fragments induce mitochondrial fragmentation, and PC1-p15 expression causes impaired fatty acid oxidation and increased lactate production, indicative of a Warburg-like phenotype. Endogenous PC1 tail fragments accumulate in renal cyst-lining cells in a mouse model of PKD. Collectively, these results identify novel mechanisms regarding the regulation and function of PC1 and suggest that C-terminal PC1 fragments may be involved in the mitochondrial and metabolic abnormalities observed in ADPKD.


Subject(s)
Mitochondrial Diseases , Polycystic Kidney, Autosomal Dominant , TRPP Cation Channels , Animals , Mice , Oxidative Stress , Polycystic Kidney, Autosomal Dominant/metabolism , Reactive Oxygen Species/metabolism , TRPP Cation Channels/genetics , TRPP Cation Channels/metabolism
13.
Turk J Gastroenterol ; 34(8): 802-812, 2023 08.
Article in English | MEDLINE | ID: mdl-37462231

ABSTRACT

BACKGROUND/AIMS: Our previous work identified the dimethyladenosine transferase 1 homolog as a novel prognostic factor for detecting human gastric carcinoma with high sensitivity and specificity. The high expression of dimethyladenosine transferase 1 is closely associated with the occurrence and progression of gastric carcinoma. However, the underlying mechanism of dimethyladenosine transferase 1 for the occurrence and development of gastric carcinoma is not well elucidated yet. MATERIALS AND METHODS: In our present study, the biological role of dimethyladenosine transferase 1 on cell proliferation, apoptosis, and cell cycle progression in human gastric carcinoma cells was investigated through in vitro and in vivo assays by the overexpression and knockdown of dimethyladenosine transferase 1 2-way authentication method. RESULTS: We found that the overexpression of dimethyladenosine transferase 1 significantly promotes cell proliferation (P < .001) and inhibition of cell apoptosis (P < .01) in SGC-7901 cells. However, the in vivo experiment results of the knockdown dimethyladenosine transferase 1 using small interfering RNAs in the MKN-45 are just the opposite. Reverse-transcriptase polymerase chain reaction and western blotting analysis revealed that overexpressed dimethyladenosine transferase 1 in SGC-7901 cells significantly activated the AKT pathway compared to control cells. In contrast, we found that apoptosis genes such as Caspase-3 and Caspase-9 were downregulated in those cells. The xenograft nude mice model exhibited increased tumor growth (P < .01) and weight loss (P < .01), with the overexpression of dimethyladenosine transferase 1 homolog in the SGC-7901 cells. These results have been further confirmed through backward verification in dimethyladenosine transferase 1 knockdown cells. CONCLUSIONS: Taken together, our results indicated that the dimethyladenosine transferase 1 plays a crucial role in stimulating cancer cell proliferation and contributes to apoptosis resistance in human gastric carcinoma. Meanwhile, it provides a potential therapeutic target for gastric carcinoma treatment and is worthy of further studies.


Subject(s)
Carcinoma , Stomach Neoplasms , Animals , Mice , Humans , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Transferases/genetics , Transferases/metabolism , Mice, Nude , Cell Line, Tumor , Apoptosis/genetics , Carcinoma/pathology , Stomach Neoplasms/pathology , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic
14.
Biochem Biophys Res Commun ; 676: 182-189, 2023 10 08.
Article in English | MEDLINE | ID: mdl-37523816

ABSTRACT

It has been reported that cadherin 6 (CDH6) upregulation is associated with enhanced epithelial-to-mesenchymal transition (EMT) in several types of solid tumor cells. The current study aimed to explore the effect of CDH6 on the migration and invasion of stomach adenocarcinoma (STAD) cells, the transcription factors involved in CDH6 dysregulation and their effect on mitochondrial fission. Bioinformatics analysis was performed using data extracted from the Genotype-Tissue Expression Project, the Cancer Genome Atlas and Kaplan-Meier plotter. AGS and HGC27 cells were used to establish an in vitro STAD cell model. The results showed that higher CDH6 expression was associated with significantly shorter overall survival in patients with STAD. In addition, CDH6 overexpression promoted wound healing, enhanced the invasion ability of tumor cells and increased mitochondrial fission. Glioma-associated oncogene family zinc finger 2 (GLI2) could bind to the CDH6 promoter and activate its transcription. Fluorescent labeling also showed that GLI2 overexpression promoted mitochondrial fission. However, CDH6 silencing significantly reduced mitochondrial fragmentation. Besides, GLI2 overexpression notably upregulated phosphorylated-focal adhesion kinase and dynamin-related protein 1. However, the above effects were largely abrogated by CDH6 knockdown. In conclusion, the present study suggested that the novel GLI2/CDH6 axis could enhance the migration, invasion and mitochondrial fission of STAD cells.


Subject(s)
Adenocarcinoma , Stomach Neoplasms , Humans , Adenocarcinoma/genetics , Cadherins/metabolism , Cell Line, Tumor , Cell Movement/genetics , Epithelial-Mesenchymal Transition/genetics , Gene Expression Regulation, Neoplastic , Mitochondrial Dynamics , Nuclear Proteins/metabolism , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology , Zinc Finger Protein Gli2/metabolism
15.
Cell Rep ; 42(6): 112550, 2023 06 27.
Article in English | MEDLINE | ID: mdl-37224018

ABSTRACT

Diabetic kidney disease (DKD) is the most prevalent chronic kidney disease. Macrophage infiltration in the kidney is critical for the progression of DKD. However, the underlying mechanism is far from clear. Cullin 4B (CUL4B) is the scaffold protein in CUL4B-RING E3 ligase complexes. Previous studies have shown that depletion of CUL4B in macrophages aggravates lipopolysaccharide-induced peritonitis and septic shock. In this study, using two mouse models for DKD, we demonstrate that myeloid deficiency of CUL4B alleviates diabetes-induced renal injury and fibrosis. In vivo and in vitro analyses reveal that loss of CUL4B suppresses migration, adhesion, and renal infiltration of macrophages. Mechanistically, we show that high glucose upregulates CUL4B in macrophages. CUL4B represses expression of miR-194-5p, which leads to elevated integrin α9 (ITGA9), promoting migration and adhesion. Our study suggests the CUL4B/miR-194-5p/ITGA9 axis as an important regulator for macrophage infiltration in diabetic kidneys.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , MicroRNAs , Animals , Mice , Cullin Proteins/genetics , Cullin Proteins/metabolism , Diabetes Mellitus/metabolism , Diabetic Nephropathies/genetics , Diabetic Nephropathies/metabolism , Integrin alpha Chains/metabolism , Macrophages/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism
16.
Pathol Res Pract ; 246: 154496, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37178619

ABSTRACT

BACKGROUND: Tumor drug resistance is a leading cause of tumor treatment failure. To date, the association between FOS-Like antigen-1 (FOSL1) and chemotherapy sensitivity in colon cancer is unclear. The present study investigated the molecular mechanism of FOSL1 regulating 5-Fluorouracil (5-FU) resistance in colon cancer. METHODS: FOSL1 expression in colon cancer was analyzed by bioinformatics methods, and its downstream regulatory factors were predicted. Pearson correlation analyzed the expression of FOSL1 and downstream regulatory gene. Meanwhile, the expression of FOSL1 and its downstream factor Pleckstrin Homology-Like Domain Family A Member 2 (PHLDA2) in colon cancer cell lines was measured by qRT-PCR and western blot. The regulatory relationship between FOSL1 and PHLDA2 was verified by chromatin immunoprecipitation (ChIP) assay and dual-luciferase reporter assay. The effects of the FOSL1/PHLDA2 axis on the resistance in colon cancer cells to 5-FU were analyzed by cell experiments. RESULTS: FOSL1 expression was evidently up-regulated in colon cancer and 5-FU resistant cells. FOSL1 was positively correlated with PHLDA2 in colon cancer. In vitro cell assays showed that low expression of FOSL1 significantly enhanced 5-FU sensitivity in colon cancer cells, significantly suppressed the proliferation of cancer cells, and induced apoptosis. Overexpression of FOSL1 presented the opposite regulatory trend. Mechanistically, FOSL1 activated PHLDA2 and up-regulated its expression. Moreover, by activating glycolysis, PHLDA2 promoted 5-Fu resistance and cell proliferation, and reduced cell apoptosis in colon cancer. CONCLUSION: Down-regulated FOSL1 expression could enhance the 5-FU sensitivity of colon cancer cells, and FOSL1/PHLDA2 axis may be an effective target for overcoming chemotherapy resistance in colon cancer.


Subject(s)
Colonic Neoplasms , Drug Resistance, Neoplasm , Fluorouracil , Nuclear Proteins , Proto-Oncogene Proteins c-fos , Humans , Cell Line, Tumor , Colonic Neoplasms/drug therapy , Colonic Neoplasms/genetics , Proto-Oncogene Proteins c-fos/genetics , Nuclear Proteins/genetics , Fluorouracil/pharmacology , Apoptosis , Cell Proliferation , Computational Biology
17.
Small Methods ; 7(7): e2300071, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37035955

ABSTRACT

Bifunctional electrocatalysts with superior activity and durability are of great importance for electrocatalytic water splitting. Herein, hierarchical structured CoO/CoP heterojunctions are successfully designed as highly efficient and freestanding bifunctional electrocatalysts toward overall water splitting. The unique microstructure combining two-dimensional nanosheets with one-dimensional nanowires enables numerous exposed active sites, shortened ion-diffusion pathways, and enhanced conductivity, significantly improving performance. Such freestanding electrodes achieve high current density over 400 mA cm-2 at low overpotentials and have exceptional electrocatalytic activity as well as long-term durability for both hydrogen and oxygen evolution reactions under alkaline conditions. Remarkably, a high current density of 20 mA cm-2 is generated at a low cell voltage of 1.56 V in an alkaline water electrolyzer, originating from synergistic interactions between CoO and CoP exposing active sites and facilitating charge transfer and enhancing kinetics. This work provides new insight into designing low-cost but high-performance bifunctional electrocatalysts for practical water splitting.

18.
J Colloid Interface Sci ; 633: 243-253, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36459931

ABSTRACT

HYPOTHESIS: In xanthate flotation system, the aggregation of serpentine on sulfide minerals significantly weakened their floatability. And it was generally assumed that the electrostatic attraction was of the dominant driver for coating of serpentine slimes. In this paper, the hydrophobic interaction between the "talc-like" cleavage plane of serpentine and the xanthate-hydrophobized surface of sulfide minerals was proposed as the dominated driver. EXPERIMENTS: To evaluate the aggregation of serpentine on pyrite surface, a novel experimental protocol was designed, and the aggregation behavior and mechanism in the absence and presence of sodium isobutyl xanthate (SIBX) were explored through in situ optical microscope, micro-flotation, contact angle, zeta potential and FT-IR. Afterwards, the disaggregation mechanism of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) to the aggregates of serpentine on pyrite surface was revealed. FINDINGS: The electrostatic attraction facilitated the slight aggregation of serpentine slimes on bare pyrite surface. The hydrophobic interaction between the "talc-like" plane of serpentine and SIBX-covered pyrite significantly promoted the aggregation between them, which remarkably weakened the floatability of pyrite. The attendance of HEDP anions reversed the surface potential of the octahedral Mg-O layers of serpentine from the positive into the negative, thus to prevent the aggregation of the HEDP-anchored serpentine with the SIBX-covered pyrite via the strong electrostatic repulsion between them. As a result, the disaggregation as well as SIBX flotation separation of pyrite from serpentine was realized. This investigation also provided new insights into the aggregation and disaggregation between serpentine and sulfide minerals during froth flotation.

19.
Arch Suicide Res ; 27(4): 1245-1260, 2023.
Article in English | MEDLINE | ID: mdl-36028924

ABSTRACT

We investigated the impact of the COVID-19 pandemic on call volumes and call characteristics using data from a national crisis helpline. Data were extracted for 215,066 calls to Taiwan's national suicide prevention hotline (January 2018-May 2020). We used negative binomial regression to investigate changes in the weekly number of calls during the early period of the COVID-19 outbreak (January 21, 2020-May 25, 2020), relative to that expected according to the pre-pandemic trend. The call characteristics during the pandemic period (February 18, 2020-May 31, 2020) were compared between COVID-19 related vs unrelated calls. Higher-than-expected call volumes started from the 6th week of the pandemic and reached a peak in the 14th week, which was 38% (rate ratio = 1.38, 95% confidence interval 1.26-1.51) higher than that expected based on the pre-pandemic trend. The higher-than-expected call volumes were mainly attributable to higher-than-expected calls from non-suicidal and male callers. Calls in which COVID-19 was mentioned (13.2%) were more likely to be from male and first-time callers, occur outside 12 am-6 am, last less than 5 min, and were less likely to be from callers who had previous suicide attempts, recent suicidal ideation or suicide plans or actions than COVID-19 unrelated calls. Callers who made COVID-19 related calls were more likely to request information than other callers. Crisis helplines should strategically adapt to the increased need and callers' specific concerns related to the outbreak.

20.
Crisis ; 44(6): 458-469, 2023 Nov.
Article in English | MEDLINE | ID: mdl-35983713

ABSTRACT

Background: The COVID-19 pandemic and its consequences may affect population mental health and suicide risk. Aims: To explore the experiences among suicidal individuals who made calls to a suicide prevention hotline and to identify factors and psychological responses that may influence suicide risk. Method: We identified 60 eligible recorded calls to Taiwan's suicide prevention hotline (January 23, 2020-May 31, 2020) and analyzed the transcripts using a framework analysis. Results: We identified three themes: (a) effects of the COVID-19 pandemic on society (impacts on local economies, the fear of contagion, and disruptions caused by outbreak control measures); (b) stress experienced by callers, including increased challenges (financial burden, restricted freedom of movement, interpersonal conflicts, feelings of uncertainty, and education/career interruption) and reduced support (reduced access to health services and social support); and (c) the callers' psychological responses to stress, including anxiety, sleep disturbance, depression, loneliness, hopelessness, and entrapment, which may increase suicide risk. Limitations: Only the experiences among those who sought help by calling the hotline during the early months of the pandemic in 2020 were explored. Conclusion: Our findings revealed the potential process underlying the impact of the COVID-19 pandemic on suicide risk and have implications for prevention and intervention strategies.


Subject(s)
COVID-19 , Humans , Pandemics , Hotlines , Suicide Prevention , Suicidal Ideation
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