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1.
Cell Rep ; : 114536, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39096901

RESUMO

Monocytic acute myeloid leukemia (AML) responds poorly to current treatments, including venetoclax-based therapy. We conducted in vivo and in vitro CRISPR-Cas9 library screenings using a mouse monocytic AML model and identified SETDB1 and its binding partners (ATF7IP and TRIM33) as crucial tumor promoters in vivo. The growth-inhibitory effect of Setdb1 depletion in vivo is dependent mainly on natural killer (NK) cell-mediated cytotoxicity. Mechanistically, SETDB1 depletion upregulates interferon-stimulated genes and NKG2D ligands through the demethylation of histone H3 Lys9 at the enhancer regions, thereby enhancing their immunogenicity to NK cells and intrinsic apoptosis. Importantly, these effects are not observed in non-monocytic leukemia cells. We also identified the expression of myeloid cell nuclear differentiation antigen (MNDA) and its murine counterpart Ifi203 as biomarkers to predict the sensitivity of AML to SETDB1 depletion. Our study highlights the critical and selective role of SETDB1 in AML with granulo-monocytic differentiation and underscores its potential as a therapeutic target for current unmet needs.

2.
J Clin Oncol ; : JCO2401125, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39137386

RESUMO

PURPOSE: Nivolumab plus relatlimab and nivolumab plus ipilimumab have been approved for advanced melanoma on the basis of the phase II/III RELATIVITY-047 and phase III CheckMate 067 trials, respectively. As no head-to-head trial comparing these regimens exists, an indirect treatment comparison was conducted using patient-level data from each trial. METHODS: Inverse probability of treatment weighting (IPTW) adjusted for baseline characteristic differences. Minimum follow-ups (RELATIVITY-047, 33 months; CheckMate 067, 36 months) were selected to best align assessments. Outcomes included progression-free survival (PFS), confirmed objective response rate (cORR), and melanoma-specific survival (MSS) per investigator; overall survival (OS); and treatment-related adverse events (TRAEs). A Cox regression model compared PFS, OS, and MSS. A logistic regression model compared cORRs. Subgroup analyses were exploratory. RESULTS: After IPTW, key baseline characteristics were balanced for nivolumab plus relatlimab (n = 339) and nivolumab plus ipilimumab (n = 297). Nivolumab plus relatlimab demonstrated similar PFS (hazard ratio [HR], 1.08 [95% CI, 0.88 to 1.33]), cORR (odds ratio, 0.91 [95% CI, 0.73 to 1.14]), OS (HR, 0.94 [95% CI, 0.75 to 1.19]), and MSS (HR, 0.86 [95% CI, 0.67 to 1.12]) to nivolumab plus ipilimumab. Subgroup comparisons showed larger numerical differences favoring nivolumab plus ipilimumab with acral melanoma, BRAF-mutant melanoma, and lactate dehydrogenase >2 × upper limit of normal, but were limited by small samples. Nivolumab plus relatlimab was associated with fewer grade 3-4 TRAEs (23% v 61%) and any-grade TRAEs leading to discontinuation (17% v 41%). CONCLUSION: Nivolumab plus relatlimab demonstrated similar efficacy to nivolumab plus ipilimumab in the overall population, including most-but not all-subgroups, and improved safety in patients with untreated advanced melanoma. Results should be interpreted with caution.

3.
Glob Chang Biol ; 30(8): e17454, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39132898

RESUMO

Tropical and subtropical evergreen broadleaved forests (TEFs) contribute more than one-third of terrestrial gross primary productivity (GPP). However, the continental-scale leaf phenology-photosynthesis nexus over TEFs is still poorly understood to date. This knowledge gap hinders most light use efficiency (LUE) models from accurately simulating the GPP seasonality in TEFs. Leaf age is the crucial plant trait to link the dynamics of leaf phenology with GPP seasonality. Thus, here we incorporated the seasonal leaf area index of different leaf age cohorts into a widely used LUE model (i.e., EC-LUE) and proposed a novel leaf age-dependent LUE model (denoted as LA-LUE model). At the site level, the LA-LUE model (average R2 = .59, average root-mean-square error [RMSE] = 1.23 gC m-2 day-1) performs better than the EC-LUE model in simulating the GPP seasonality across the nine TEFs sites (average R2 = .18; average RMSE = 1.87 gC m-2 day-1). At the continental scale, the monthly GPP estimates from the LA-LUE model are consistent with FLUXCOM GPP data (R2 = .80; average RMSE = 1.74 gC m-2 day-1), and satellite-based GPP data retrieved from the global Orbiting Carbon Observatory-2 (OCO-2) based solar-induced chlorophyll fluorescence (SIF) product (GOSIF) (R2 = .64; average RMSE = 1.90 gC m-2 day-1) and the reconstructed TROPOspheric Monitoring Instrument SIF dataset using machine learning algorithms (RTSIF) (R2 = .78; average RMSE = 1.88 gC m-2 day-1). Typically, the estimated monthly GPP not only successfully represents the unimodal GPP seasonality near the Tropics of Cancer and Capricorn, but also captures well the bimodal GPP seasonality near the Equator. Overall, this study for the first time integrates the leaf age information into the satellite-based LUE model and provides a feasible implementation for mapping the continental-scale GPP seasonality over the entire TEFs.


Assuntos
Florestas , Folhas de Planta , Tecnologia de Sensoriamento Remoto , Estações do Ano , Folhas de Planta/crescimento & desenvolvimento , Fotossíntese , Modelos Teóricos , Luz , Árvores/crescimento & desenvolvimento , Modelos Biológicos , Clima Tropical
4.
Int J Biol Macromol ; 277(Pt 4): 134512, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39111480

RESUMO

With the increasing emphasis on sustainability and eco-friendliness, a novel biodegradable packaging materials has received unprecedented attention. Nanocellulose, owing to its high crystallinity, degradability, minimal toxicity, and outstanding biocompatibility, has gained considerable interest in the field of sustainable packaging. This review provided a comprehensive perspective about the recent advances and future development of cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs). We first introduced the utilization of agricultural waste for nanocellulose production, such as straw, bagasse, fruit byproducts, and shells. Next, we discussed the preparation process of nanocellulose from various agricultural wastes and expounded the advantages and shortcomings of different methods. Subsequently, this review offered an in-depth investigation on the application of nanocellulose in food packaging, especially the function and packaged form of nanocellulose on food preservation. Finally, the safety evaluation of nanocellulose in food packaging is conducted to enlighten and promote the perfection of relevant regulatory documents. In short, this review provided valuable insights for potential research on the biobased materials utilized in future food packaging.

5.
PLoS One ; 19(8): e0308477, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39146251

RESUMO

Pilot Free Trade Zones (PFTZs) are a crucial new platform for China to build a more open economic system. Existing literature primarily focuses on the 'Bring In' effect of PFTZs, often overlooking the importance of 'Going Out' aspects. To bridge this gap, this paper uses data from China's Shanghai and Shenzhen A-share listed enterprises from 2007 to 2021 and constructs a time-varying difference-in-differences (DID) model to test the impact of establishment of PFTZs on international expansion of enterprises. The study finds that establishment of PFTZs can significantly promote international expansion of enterprises, with a more pronounced effect on the scope of international expansion than on its depth. Mechanism analysis reveals that PFTZs can facilitate international expansion of enterprises by driving digital transformation, enhancing total factor productivity and management efficiency, and alleviating financing constraints. Notably, senior managers with overseas work experience play a crucial role in enhancing this relationship. Further, PFTZs not only have a linkage effect with the Belt and Road Initiative but also a radiation effect on neighboring cities. This study provides an analytical perspective and empirical evidence for evaluating policy effects of PFTZs and offers valuable insights that will enable PFTZ policies to be refined and facilitate successful implementation of the 'Going Out' strategy.


Assuntos
Comércio , China , Humanos , Projetos Piloto , Cidades , Internacionalidade
6.
J Electrocardiol ; 86: 153779, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39151303

RESUMO

BACKGROUND: Immune checkpoint inhibitor (ICI) has become a major breakthrough in the field of tumor therapy, leading to improved survival. This study evaluated the clinical and electrocardiographic characteristics of patients with ICI-related myocarditis. METHODS: Patients with ICI-related myocarditis were enrolled from 4 centers in China until September 2023. Demographic data (age, sex, comorbidity), types of ICI, clinical manifestations, electrocardiogram (ECG) and treatment were analyzed retrospectively. Arrhythmia and characteristics of ECG were compared according to prognosis and grading. RESULTS: A total of 29 participants (13 females with a median age of 63.25 years) with ICI-related myocarditis were enrolled. Lung cancer was the most, with a proportion of 31.03 % (9/29). The median time from the first administration of ICI to the diagnosis of myocarditis was 50 days. Camrelizumab was the main type of ICI (9/29). Most patients had non-specific symptoms, dyspnea (n = 16) and palpitation (n = 9) were common. The overall mortality rate was 37.93 % (11/29) with a median follow-up of 9(4,11) days. Compared with the survivors, P-wave abnormality was more common in participants who were dead (24.14 %vs6.90 %, p = 0.010). A total of 19 patients with severe ICI-related myocarditis were included in this study. The proportions of sinus tachycardia (34.48 %vs0.00 %, p = 0.005), premature ventricular complex (27.59 %vs0.00 %, p = 0.027) and atrioventricular block (34.48 %vs3.45 %, p = 0.044) were higher in severe ICI-related myocarditis. CONCLUSIONS: Clinical manifestations of ICI-related myocarditis usually lacked specificity. ECGs can be manifested as new-onset arrhythmias, ST-T segment changes, fragmented QRS complex, abnormal P wave, prolonged QTc interval and multi­lead low voltage.

7.
Sci Total Environ ; : 175565, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39151620

RESUMO

Long-chain fatty acids (LCFAs) are recognized as a significant inhibitory factor in anaerobic digestion of food waste (FW), yet they are inevitably present in FW due to lipid hydrolysis. Given their distinct synthesis mechanism from traditional anaerobic digestion, little is known about the effect of LCFAs on FW acidogenic fermentation. This study reveals that total volatile fatty acids (VFAs) production increased by 9.98 % and 4.03 % under stearic acid and oleic acid loading, respectively. Acetic acid production increased by 20.66 % under stearic acid loading compared to the control group (CK). However, the LCFA stress restricted the degradation of solid organic matter, particularly under oleic acid stress. Analysis of microbial community structure and quorum sensing (QS) indicates that LCFA stress enhanced the relative abundance of Lactobacillus and Klebsiella. In QS system, the relative abundance of luxS declined from 0.157 % to 0.116 % and 0.125 % under oleic acid and stearic acid stress, respectively. LCFA stress limited the Autoinducer-2 (AI-2) biosynthesis, suggesting that microorganisms cannot use QS to resist the LCFA stress. Metagenomic sequencing showed that LCFA stress promoted acetic acid production via the conversion of pyruvate and acetyl-CoA to acetate. Direct conversion of pyruvate to acetic acid increased by 47.23 % compared to the CK group, accounting for the enhanced acetic acid production under stearic acid loading. The abundance of ß-oxidation pathway under stearic acid loading was lower than under oleic acid loading. Overall, the stimulating direct conversion of pyruvate plays a pivotal role in enhancing acetic acid biosynthesis under stearic acid loading, providing insights into the effect of LCFA on mechanism of FW acidogenic fermentation.

8.
Autoimmun Rev ; : 103600, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39151642

RESUMO

The lungs are a principal factor in the increased morbidity and mortality observed in patients with Connective Tissue Disease (CTD), frequently presenting as CTD-associated Interstitial Lung Disease (ILD). Currently, there is a lack of comprehensive descriptions of the pulmonary cells implicated in the development of CTD-ILD. This review leverages the Human Lung Cell Atlas (HLCA) and spatial multi-omics atlases to discuss the advancements in research on the pathogenesis of CTD-ILD from a pulmonary cell perspective. This facilitates a more precise localization of disease sites and a more systematic consideration of disease progression, supporting further mechanistic studies and targeted therapies.

9.
Prev Med ; : 108103, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39151805

RESUMO

BACKGROUND: The potential adverse effects of plant-based diets on bone health have raised significant concern, while the prospective evidence is limited. This study aimed to evaluate the association between plant-based diet indexes and incident osteoporosis while exploring the underlying mechanisms involved in this relationship. METHODS: The analysis included 202,063 UK Biobank participants conducted between 2006 and 2022. Plant-based diet indexes (hPDI and uPDI) were calculated using the 24-h dietary questionnaire. Cox proportional risk regression and mediation analysis were used to explore the associations of plant-based diet indexes with osteoporosis, estimating the contribution of BMI and blood markers. RESULTS: We found the highest quintile for hPDI (HR = 1.16; 95% CI: 1.05 to 1.28) and uPDI (HR = 1.15; 95% CI: 1.05 to 1.26) were associated with an increased risk of osteoporosis. BMI was identified as an important mediator in the association between hPDI and osteoporosis, with mediation proportions of 46.17%. For blood markers, the mediating (suppressing) effects of C-reactive protein, alkaline phosphatase, and insulin-like growth factor-1 on the association between uPDI (hPDI) and osteoporosis were significant, ranging from 5.63%-16.87% (4.57%-6.22%). CONCLUSION: Adherence to a plant-based diet is associated with a higher risk of osteoporosis, with BMI and blood markers potentially contributing to this relationship. Notably, even a healthy plant-based diet necessitates attention to weight management to mitigate its impact on bone loss. These findings emphasize the importance of personalized dietary recommendations and lifestyle interventions to decrease the risk of osteoporosis.

10.
Mol Neurobiol ; 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39136907

RESUMO

Neuropathic pain (NP) is a chronic pain caused by injury or disease of the somatosensory nervous system, or it can be directly caused by disease. It often presents with clinical features like spontaneous pain, hyperalgesia, and dysesthesia. At present, voltage-gated calcium ion channels (VGCCs) are known to be closely related to the development of NP, especially the α2δ subunit. The α2δ subunit is a regulatory subunit of VGCCs. It exists mainly in the brain and peripheral nervous system, especially in nerve cells, and it plays a crucial part in regulating presynaptic and postsynaptic functions. Furthermore, the α2δ subunit influences neuronal excitation and pain signaling by promoting its expression and localization through binding to VGCC-related subunits. The α2δ subunit is widely used in the management of NP as a target of antiepileptic drugs gabapentin and pregabalin. Although drug therapy is one of the treatments for NP, its clinical application is limited due to the adverse reactions caused by drug therapy. Therefore, further research on the therapeutic target α2δ subunit is needed, and attempts are made to obtain an effective treatment for relieving NP without side effects. This review describes the current associated knowledge on the function of the α2δ subunit in perceiving and modulating NP.

11.
Bioresour Technol ; 409: 131240, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39122129

RESUMO

To promote the sustainability of hydrothermal liquefaction (HTL) for biofuel production, fungal fermentation was investigated to treat HTL aqueous phase (HTLAP) from corn stover. The most promising fungus, Aspergillus niger demonstrated superior tolerance to HTLAP and capability to produce oxalic acid as a value-added product. The fungal-bacterial co-culture of A. niger and Rhodococcus jostii was beneficial at low COD (chemical oxygen demand) loading of 3800 mg/L in HTLAP, achieving 69% COD removal while producing 0.5 g/L oxalic acid and 11% lipid content in microbial biomass. However, higher COD loading of 4500, 6040, and 7800 mg/L significantly inhibited R. jostii, but promoted A. niger growth with increased oxalic acid production while COD removal remained similar (58-65%). Additionally, most total organic carbon (TOC) in HTLAP was transformed into oxalic acid, representing 46-56% of the consumed TOC. These findings highlighted the potential of fungi for bio-upcycling of HTLAP into value-added products.

12.
Org Lett ; 26(32): 6825-6829, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39110706

RESUMO

Herein, we report a novel strategy for the regioselective synthesis of aromatic and heteroaromatic 2,3-dihydrooxazoles from 2-alkynyl-1,3-dithianes and nitrones. This method exploits the 1,3-dithiane umpolung, nucleophilic cycloaddition, and rearrangement processes to achieve the rapid assembly of dihydrooxazole molecules. The regioselective method is extremely mild, achieving complete conversion within one min under air at 25 °C with high efficiency.

13.
Blood ; 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39088777

RESUMO

Thrombocytopenic patients require platelet transfusion to prevent and stop hemorrhage. Cold storage of platelets results in complex molecular lesions including changes in membrane microdomains that are recognized by host macrophages and hepatocyte counter-receptors, resulting in phagocytosis and clearance upon transfusion. For this reason, platelets are stored at room temperature, a method that confers increased risk of bacterial contamination. By applying signaling analysis as well as genetic and pharmacological approaches, we identified that the cold induced activation of RHOA GTPase is causal for the major hallmarks of platelet cold storage lesions. RHOA deficiency renders murine platelets insensitive to cold storage induced damage, and pharmacological inhibition by a RHOA activation inhibitor, R-G04, can prevent the cold storage induced lesions. RHOA inhibition prevents myosin activation and clathrin-independent formation and internalization of lipid rafts enriched in active glycosyltransferases as well as abnormal distribution of GpIb. RHOA inhibition further prevents the metabolic reprogramming of cold induced storage lesions and allows the maintenance of glycolytic flux and mitochondrial dependent respiration. Importantly, human platelets transfused in mice after cold storage, in the presence of R-G04 or its more potent enantiomer S-G04, can circulate in vivo at similar levels as room-temperature stored platelets while retaining their hemostatic activity in vivo as assessed by bleeding time correction of aspirin-treated mice. Our studies provide a new mechanism based translational venue to prevent cold storage induced damage useful for human platelet transfusion in thrombocytopenic patients.

14.
Bioresour Technol ; : 131298, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39153697

RESUMO

Tunnel Oxide Passivating Contacts (TOPcon) battery in the photovoltaic industry generates high ammonium wastewater during the production process, the adaptability of using the anaerobic ammonia oxidation (Anammox) process for photovoltaic wastewater (PVW) treatment is a research hotspot. Based on the analysis of photovoltaic wastewater quality, the effectiveness of nitrogen removal, sludge characteristics and microbial communities were examined. The results showed that when the influent NH4+-N concentration of PVW was lower than 150 mg·L-1, the nitrogen removal efficiency (NRE) was almost 100 %. In addition, the NRE decreased from 74 % sharply to 20 % when the NH4+-N concentration was increased from 175 mg·L-1 to 200 mg·L-1. The extracellular polymeric substances (EPS) content increased with elevated ammonium concentration in the influent, indicating that microorganisms secreted more EPS to resist elevated nitrogen loading. The main functional populations were Candidatus Kuenenia (0-24 %). The influent ammonium concentration is recommended to be < 200 mg·L-1.

15.
Food Chem X ; 23: 101609, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39100246

RESUMO

Compared to control longan, DCC-treated longan had higher pulp breakdown index, lower ATP, ADP and EC levels, and lower H+, Ca2+ and Mg2+-ATPase activities. On day 6, DCC-treated longan presented 18% higher pulp breakdown index, with 44%, 9% and 31% lower levels of ATP, ADP and EC, respectively. Additionally, DCC-treated longan showed 29%, 53%, 37% lower activity of H+-ATPase, 34%, 54%, 4% lower activity of Ca2+-ATPase, and 13%, 21%, 6% lower activity of Mg2+-ATPase in the membranes of plasma, vacuole, and mitochondria, respectively. Whereas, DS-treated longan manifested the opposite trends of DCC treatment. These results suggest that the accelerated pulp breakdown in DCC-treated longan was linked to energy deficiency and reduced energy production. However, DS treatment restrained pulp breakdown occurrence in fresh longan by maintaining a higher energy level through the elevated energy production and ATPase activity.

16.
Clinics (Sao Paulo) ; 79: 100469, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39098146

RESUMO

OBJECTIVE: To investigate the relationship between the changes of C-reactive protein to Albumin Ratio (CAR) levels and Interval Debulking Surgery (IDS) outcome after Neoadjuvant Chemotherapy (NAC) in ovarian cancer patients. METHODS: A nested case-control study for 209 patients with ovarian cancer who received NAC-IDS therapy from the First Affiliated Hospital of Bengbu Medical College between 2015‒2021 was conducted. Demographic data, laboratory indicators, and imaging examinations were collected. The outcome was regarded as optimal IDS in this study. Univariate and multivariate logistic regression analyses were performed to assess the relationship of CAR before NAC, CAR after NAC and ∆CAR with optimal IDS. The authors also performed the subgroup analysis based on menopausal state. RESULTS: The end time of follow-up was January 24, 2022. A total of 156 patients had been treated with optimal IDS, and 53 with suboptimal IDS. After adjusting age, body mass index, menopausal state, NAC drug, peritoneal perfusion and CAR before NAC, the result showed that CAR after NAC (Odds Ratio [OR = 3.48], 95% Confidence Interval [95% CI 1.28‒9.48], p = 0.015) and ∆CAR (OR = 0.29, 95% CI 0.11‒0.78, p = 0.015) were associated with optimal IDS, respectively. Additionally, the authors found a significant correlation between CAR after NAC and optimal IDS (OR = 3.16, 95% CI 1.07‒9.35, p = 0.038), and ∆CAR and optimal IDS (OR = 0.32, 95% CI 0.11‒0.94, p = 0.038) among ovarian cancer patients with menopause. CONCLUSION: CAR after NAC and ∆CAR were independent prognostic markers of optimal interval debulking surgery for ovarian cancer patients.


Assuntos
Proteína C-Reativa , Procedimentos Cirúrgicos de Citorredução , Terapia Neoadjuvante , Neoplasias Ovarianas , Humanos , Feminino , Neoplasias Ovarianas/cirurgia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/terapia , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Proteína C-Reativa/análise , Estudos de Casos e Controles , Idoso , Resultado do Tratamento , Adulto , Albumina Sérica/análise , Quimioterapia Adjuvante
18.
Diagn Microbiol Infect Dis ; 110(2): 116434, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39111107

RESUMO

The case presents a 47-year-old man with sudden abdominal pain and fever, but the cause was uncertain. Through metagenomic next-generation sequencing (mNGS) and detecting Q fever antibodies in serum, along with the patient's clinical and epidemiological history, a precise diagnosis was made, enabling timely and proper treatment.

19.
Phys Rev Lett ; 133(3): 033602, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39094149

RESUMO

With an extremely high dimensionality, the spatial degree of freedom of entangled photons is a key tool for quantum foundation and applied quantum techniques. To fully utilize the feature, the essential task is to experimentally characterize the multiphoton spatial wave function including the entangled amplitude and phase information at different evolutionary stages. However, there is no effective method to measure it. Quantum state tomography is costly, and quantum holography requires additional references. Here, we introduce quantum Shack-Hartmann wavefront sensing to perform efficient and reference-free measurement of the biphoton spatial wave function. The joint probability distribution of photon pairs at the back focal plane of a microlens array is measured and used for amplitude extraction and phase reconstruction. In the experiment, we observe that the biphoton amplitude correlation becomes weak while phase correlation shows up during free-space propagation. Our work is a crucial step in quantum physical and adaptive optics and paves the way for characterizing quantum optical fields with high-order correlations or topological patterns.

20.
Ear Hear ; 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39104002

RESUMO

OBJECTIVES: The experimental Optimized Pitch and Language (OPAL) strategy enhances coding of fundamental frequency (F0) information in the temporal envelope of electrical signals delivered to channels of a cochlear implant (CI). Previous studies with OPAL have explored performance on speech and lexical tone perception in Mandarin- and English-speaking CI recipients. However, it was not clear which cues to lexical tone (primary and/or secondary) were used by the Mandarin CI listeners. The primary aim of the present study was to investigate whether OPAL provides improved recognition of Mandarin lexical tones in both quiet and noisy environments compared with the Advanced Combination Encoder (ACE) strategy. A secondary aim was to investigate whether, and to what extent, removal of secondary (duration and intensity envelope) cues to lexical tone affected Mandarin tone perception. DESIGN: Thirty-two CI recipients with an average age of 24 (range 7 to 57) years were enrolled in the study. All recipients had at least 1 year of experience using ACE. Each subject attended two testing sessions, the first to measure baseline performance, and the second to evaluate the effect of strategy after provision of some take-home experience using OPAL. A minimum take-home duration of approximately 4 weeks was prescribed in which subjects were requested to use OPAL as much as possible but were allowed to also use ACE when needed. The evaluation tests included recognition of Mandarin lexical tones in quiet and in noise (signal to noise ratio [SNR] +5 dB) using naturally produced tones and duration/intensity envelope normalized versions of the tones; Mandarin sentence in adaptive noise; Mandarin monosyllabic and disyllabic word in quiet; a subset of Speech, Spatial, and Qualities of hearing questionnaire (SSQ, speech hearing scale); and subjective preference for strategy in quiet and noise. RESULTS: For both the natural and normalized lexical tone tests, mean scores for OPAL were significantly higher than ACE in quiet by 2.7 and 2.9%-points, respectively, and in noise by 7.4 and 7.2%-points, respectively. Monosyllabic word recognition in quiet using OPAL was significantly higher than ACE by approximately 7.5% points. Average SSQ ratings for OPAL were significantly higher than ACE by approximately 0.5 points on a 10-point scale. In quiet conditions, 14 subjects preferred OPAL, 7 expressed a preference for ACE, and 9 reported no preference. Compared with quiet, in noisy situations, there was a stronger preference for OPAL (19 recipients), a similar preference for ACE (7 recipients), while fewer expressed no preference. Average daily take-home use of ACE and OPAL was 4.9 and 7.1 hr, respectively. CONCLUSIONS: For Mandarin-speaking CI recipients, OPAL provided significant improvements to lexical tone perception for natural and normalized tones in quiet and noise, monosyllabic word recognition in quiet, and subjective ratings of speech intelligibility. Subjects accessed both primary and secondary cues to lexical tone for perception in quiet and noise conditions. The benefits of lexical tone recognition were attributed to enhanced F0 rate cues encoded by OPAL, especially in a noisy environment. The OPAL strategy was well accepted by many of the Mandarin-speaking CI recipients.

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