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1.
Phys Rev Lett ; 133(10): 101805, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39303260

RESUMO

We report the first search for the elastic scatterings between cosmic-ray boosted sub-MeV dark matter (DM) and electrons in the PandaX-4T liquid xenon experiment. Sub-MeV DM particles can be accelerated by scattering with electrons in the cosmic rays and produce detectable electron recoil signals in the detector. Using the commissioning data from PandaX-4T of 0.63 tonne·year exposure, we set new constraints on DM-electron scattering cross sections for DM masses ranging from 10 eV/c^{2} to 3 keV/c^{2}.

2.
ACS Appl Mater Interfaces ; 16(35): 46216-46225, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39169608

RESUMO

Layered P2-type sodium manganese oxide has emerged as a promising cathode candidate for sodium-ion batteries due to its appealing cost-effectiveness and high discharge voltage. However, its practical capacity within the voltage range of 2.0-4.0 V (vs Na+/Na) is relatively low, and its rate capability is hampered by the adverse charge/vacancy ordering during charge/discharge. In this study, a layered P'2/P3 mixed-phase Na0.8-aMn0.675Ni0.225Li0.1O2-x cathode with high (003) crystal plane intensity was designed by introducing oxygen vacancies to P2-structured materials. Aided by these advantages, the hybrid cathode material demonstrates impressive structural and thermal stability and faster Na-ion diffusion kinetics compared to a regular P2 material. Half-cell shows an initial discharge capacity retention of 101 mA h/g at 12 mA/g and 92.25% retention after 500 cycles at 120 mA/g. In combination with a hard carbon anode, the 0.5 A h pouch cell achieved a prevailing capacity retention of 95.2% after 2600 cycles at 36 mA/g. This work opens new dimensions for layered cathode materials with the aim of achieving superior cyclabilities.

3.
ACS Appl Mater Interfaces ; 16(31): 40805-40813, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39054601

RESUMO

Low-cost sodium-ion batteries have demonstrated great prospects in energy storage, among which layered transition metal oxides hold great potential as a cathode material. However, the notorious phase transition in layered cathode materials has greatly hampered their cycle life due to large volume changes upon desodiation/sodiation. In this study, by adopting an O3-type NaNi1/3Fe1/3Mn1/3O2 (NFM) with controlled synthesis temperatures, we have revealed that the grain size is closely related to its phase transition behaviors. The layered material with a smaller grain size and more distorted lattice tends to experience a shorter plateau of the O3-P3-O3 phase transitions during the charge/discharge process. Despite having a lower nominal discharge capacity without the phase transition plateau, its cycling stability increases from 77.4% to 96.2% after 100 cycles with greatly reduced intragranular cracks. The smaller grain size and lattice distortion act as a barrier that prevents the smooth layer from gliding upon sodium intercalation and deintercalation. This study focuses on the influence of grain size on battery cycle stability and provides a basis for future analysis of the structural instability of layered materials.

4.
Clin Colorectal Cancer ; 23(2): 118-127.e6, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38762348

RESUMO

BACKGROUND: The phase 1b KEYNOTE-651 study evaluated pembrolizumab plus chemotherapy in microsatellite stable or mismatch repair-proficient metastatic colorectal cancer. PATIENTS AND METHODS: Patients with microsatellite stable or mismatch repair-proficient metastatic colorectal cancer received pembrolizumab 200 mg every 3 weeks plus 5-fluorouracil, leucovorin, oxaliplatin (previously untreated; cohort B) or 5-fluorouracil, leucovorin, irinotecan (previously treated with fluoropyrimidine plus oxaliplatin; cohort D) every 2 weeks. Primary end point was safety; investigator-assessed objective response rate per RECIST v1.1 was secondary and biomarker analysis was exploratory. RESULTS: Thirty-one patients were enrolled in cohort B and 32 in cohort D; median follow-up was 30.2 and 33.5 months, respectively. One dose-limiting toxicity (grade 3 small intestine obstruction) occurred in cohort D. In cohort B, grade 3 or 4 treatment-related adverse events (AEs) occurred in 18 patients (58%), most commonly neutropenia and decreased neutrophil count (n = 5 each). In cohort D, grade 3 or 4 treatment-related AEs occurred in 17 patients (53%), most commonly neutropenia (n = 7). No grade 5 treatment-related AEs occurred. Objective response rate was 61% in cohort B (KRAS wildtype: 71%; KRAS mutant: 53%) and 25% in cohort D (KRAS wildtype: 47%; KRAS mutant: 6%). In both cohorts, PD-L1 combined positive score and T-cell-inflamed gene expression profiles were higher and HER2 expression was lower in responders than nonresponders. No association between tumor mutational burden and response was observed. CONCLUSION: Pembrolizumab plus 5-fluorouracil, leucovorin, oxaliplatin/5-fluorouracil, leucovorin, irinotecan demonstrated an acceptable AE profile. Efficacy data appeared comparable with current standard of care (including by KRAS mutation status). Biomarker analyses were hypothesis-generating, warranting further exploration. GOV IDENTIFIER: ClinicalTrials.gov; NCT03374254.


Assuntos
Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Camptotecina , Neoplasias Colorretais , Fluoruracila , Leucovorina , Compostos Organoplatínicos , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Leucovorina/administração & dosagem , Leucovorina/efeitos adversos , Leucovorina/uso terapêutico , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Feminino , Masculino , Pessoa de Meia-Idade , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Idoso , Camptotecina/análogos & derivados , Camptotecina/administração & dosagem , Camptotecina/uso terapêutico , Camptotecina/efeitos adversos , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Adulto , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/uso terapêutico , Instabilidade de Microssatélites/efeitos dos fármacos , Reparo de Erro de Pareamento de DNA , Irinotecano/administração & dosagem , Irinotecano/efeitos adversos , Oxaliplatina/administração & dosagem , Idoso de 80 Anos ou mais
5.
Eur J Cancer ; 205: 114036, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38749110

RESUMO

BACKGROUND: The randomized, open-label, phase III LYNK-003 study assessed the efficacy of first-line maintenance olaparib, alone or in combination with bevacizumab, versus bevacizumab plus a fluoropyrimidine in participants with unresectable or metastatic colorectal cancer (mCRC). We present results of the prespecified interim futility analysis. METHODS: Eligible participants were ≥18 years of age with unresectable or mCRC that had not progressed after induction with first-line bevacizumab plus 5-fluorouracil plus oxaliplatin plus leucovorin (FOLFOX) or capecitabine plus oxaliplatin (CAPOX). Participants were randomly assigned 1:1:1 to olaparib plus bevacizumab, olaparib alone, or bevacizumab plus a fluoropyrimidine (5-fluorouracil or capecitabine). The primary end point was progression-free survival (PFS) per RECIST v1.1 by central review. RESULTS: Between August 2020 and May 2022, 309 participants were assigned to olaparib plus bevacizumab (n = 104), olaparib (n = 107), or bevacizumab plus fluoropyrimidine (n = 98). At interim analysis, with a median follow-up of 7.6 months (range 0.1-19.7 months), the median PFS was 3.7 months (95% CI 2.8-5.3) with olaparib plus bevacizumab (HR 1.52; 95% CI 1.02-2.27; P = 0.982) and 3.5 months (95% CI 2.0-3.7) with olaparib (HR 2.11; 95% CI 1.39-3.18; P = 0.999) versus 5.6 months (95% CI 3.8-5.9) with bevacizumab plus fluoropyrimidine. Treatment-related adverse events occurred in 64 (62%), 52 (50%), and 57 (59%) participants, respectively. There were no treatment-related deaths. CONCLUSION: The LYNK-003 study was stopped prematurely as criteria for futility were met. Maintenance olaparib with or without bevacizumab did not demonstrate clinical efficacy compared with bevacizumab plus a fluoropyrimidine. GOV REGISTRATION: NCT04456699.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Bevacizumab , Neoplasias Colorretais , Fluoruracila , Ftalazinas , Piperazinas , Humanos , Bevacizumab/administração & dosagem , Bevacizumab/efeitos adversos , Ftalazinas/administração & dosagem , Ftalazinas/efeitos adversos , Ftalazinas/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Neoplasias Colorretais/mortalidade , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/uso terapêutico , Adulto , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Quimioterapia de Manutenção/métodos , Capecitabina/administração & dosagem , Capecitabina/efeitos adversos , Capecitabina/uso terapêutico , Idoso de 80 Anos ou mais , Leucovorina/administração & dosagem , Leucovorina/uso terapêutico , Leucovorina/efeitos adversos , Intervalo Livre de Progressão
6.
Clin Colorectal Cancer ; 23(2): 183-193, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38653648

RESUMO

BACKGROUND: Cohorts A, C, and E of the phase Ib KEYNOTE-651 study evaluated pembrolizumab + binimetinib ± chemotherapy in microsatellite stable/mismatch repair-proficient metastatic colorectal cancer. PATIENTS AND METHODS: Patients received pembrolizumab 200 mg every 3 weeks plus binimetinib 30 mg twice daily alone (cohort A; previously treated with any chemotherapy) or with 5-fluorouracil, leucovorin, oxaliplatin (cohort C; previously untreated) or 5-fluorouracil, leucovorin, irinotecan (cohort E; previously treated with 1 line of therapy including fluoropyrimidine + oxaliplatin-based regimen) every 2 weeks. Binimetinib dose-escalation to 45 mg twice daily was planned in all cohorts using a modified toxicity probability interval design (target dose-limiting toxicity [DLT], 30%). The primary endpoint was safety; investigator-assessed objective response rate was secondary. RESULTS: In cohort A, 1/6 patients (17%) had DLTs with binimetinib 30 mg; none occurred in 14 patients with 45 mg. In cohort C, 3/9 patients (33%) had DLTs with binimetinib 30 mg; dose was not escalated to 45 mg. In cohort E, 1/5 patients (20%) had DLTs with binimetinib 30 mg; 5/10 patients (50%) had DLTs with 45 mg. Enrollment was stopped in cohort E binimetinib 45 mg and deescalated to 30 mg; 2/4 additional patients (50%) had DLTs with binimetinib 30 mg (total 3/9 [33%] had DLTs with binimetinib 30 mg). Objective response rate was 0% in cohort A, 9% in cohort C, and 15% in cohort E. CONCLUSION: Per DLT criteria, binimetinib + pembrolizumab (cohort A) was tolerable, binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, oxaliplatin (cohort C) did not qualify for binimetinib dose escalation to 45 mg, and binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, irinotecan (cohort E) required binimetinib dose reduction from 45 to 30 mg. No new safety findings were observed across cohorts. There was no apparent additive efficacy when binimetinib + pembrolizumab was added to chemotherapy. Data did not support continued enrollment in cohorts C and E.


Assuntos
Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Benzimidazóis , Neoplasias Colorretais , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Feminino , Masculino , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Pessoa de Meia-Idade , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Idoso , Adulto , Benzimidazóis/administração & dosagem , Benzimidazóis/efeitos adversos , Benzimidazóis/uso terapêutico , Fluoruracila/administração & dosagem , Fluoruracila/uso terapêutico , Irinotecano/administração & dosagem , Irinotecano/uso terapêutico , Oxaliplatina/administração & dosagem , Reparo de Erro de Pareamento de DNA , Leucovorina/administração & dosagem , Leucovorina/uso terapêutico , Leucovorina/efeitos adversos , Instabilidade de Microssatélites , Idoso de 80 Anos ou mais
7.
Phys Rev Lett ; 132(15): 152502, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38682998

RESUMO

^{134}Xe is a candidate isotope for neutrinoless double beta decay (0νßß) search. In addition, the two-neutrino case (2νßß) allowed by the standard model of particle physics has not yet been observed. With the 656-kg natural xenon in the fiducial volume of the PandaX-4T detector, which contains 10.4% of ^{134}Xe, and its initial 94.9-day exposure, we have established the most stringent constraints on 2νßß and 0νßß of ^{134}Xe half-lives, with limits of 2.8×10^{22} yr and 3.0×10^{23} yr at 90% confidence level, respectively. The 2νßß (0νßß) limit surpasses the previously reported best result by a factor of 32 (2.7), highlighting the potential of large monolithic natural xenon detectors for double beta decay searches.

9.
Phys Rev Lett ; 131(19): 191002, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38000419

RESUMO

We report results of a search for dark-matter-nucleon interactions via a dark mediator using optimized low-energy data from the PandaX-4T liquid xenon experiment. With the ionization-signal-only data and utilizing the Migdal effect, we set the most stringent limits on the cross section for dark matter masses ranging from 30 MeV/c^{2} to 2 GeV/c^{2}. Under the assumption that the dark mediator is a dark photon that decays into scalar dark matter pairs in the early Universe, we rule out significant parameter space of such thermal relic dark-matter model.

10.
Front Endocrinol (Lausanne) ; 14: 1230921, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37929026

RESUMO

Introduction: The aim of this study was to cluster patients with chronic complications of type 2 diabetes mellitus (T2DM) by cluster analysis in Dalian, China, and examine the variance in risk of different chronic complications and metabolic levels among the various subclusters. Methods: 2267 hospitalized patients were included in the K-means cluster analysis based on 11 variables [Body Mass Index (BMI), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Glucose, Triglycerides (TG), Total Cholesterol (TC), Uric Acid (UA), microalbuminuria (mAlb), Insulin, Insulin Sensitivity Index (ISI) and Homa Insulin-Resistance (Homa-IR)]. The risk of various chronic complications of T2DM in different subclusters was analyzed by multivariate logistic regression, and the Kruskal-Wallis H test and the Nemenyi test examined the differences in metabolites among different subclusters. Results: Four subclusters were identified by clustering analysis, and each subcluster had significant features and was labeled with a different level of risk. Cluster 1 contained 1112 inpatients (49.05%), labeled as "Low-Risk"; cluster 2 included 859 (37.89%) inpatients, the label characteristics as "Medium-Low-Risk"; cluster 3 included 134 (5.91%) inpatients, labeled "Medium-Risk"; cluster 4 included 162 (7.15%) inpatients, and the label feature was "High-Risk". Additionally, in different subclusters, the proportion of patients with multiple chronic complications was different, and the risk of the same chronic complication also had significant differences. Compared to the "Low-Risk" cluster, the other three clusters exhibit a higher risk of microangiopathy. After additional adjustment for 20 covariates, the odds ratios (ORs) and 95% confidence intervals (95%CI) of the "Medium-Low-Risk" cluster, the "Medium-Risk" cluster, and the"High-Risk" cluster are 1.369 (1.042, 1.799), 2.188 (1.496, 3.201), and 9.644 (5.851, 15.896) (all p<0.05). Representatively, the "High-Risk" cluster had the highest risk of DN [OR (95%CI): 11.510(7.139,18.557), (p<0.05)] and DR [OR (95%CI): 3.917(2.526,6.075), (p<0.05)] after 20 variables adjusted. Four metabolites with statistically significant distribution differences when compared with other subclusters [Threonine (Thr), Tyrosine (Tyr), Glutaryl carnitine (C5DC), and Butyryl carnitine (C4)]. Conclusion: Patients with chronic complications of T2DM had significant clustering characteristics, and the risk of target organ damage in different subclusters was significantly different, as were the levels of metabolites. Which may become a new idea for the prevention and treatment of chronic complications of T2DM.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Fatores de Risco , Glicemia/metabolismo , Insulina , Carnitina
12.
Int Ophthalmol ; 43(12): 4595-4604, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37688651

RESUMO

PURPOSE: This study investigated the protective effect of probucol on Müller cells exposed to high glucose conditions and examined potential mechanisms of action. METHODS: Primary human retinal Müller cells were incubated with high glucose (HG, 35 mM) in the present or absence of different concentrations of probucol for 24 h. Cell viability was determined using the CCK-8 method. Mitochondrial membrane potential (MMP) was measured using JC-1 staining and cell cycle by flow cytometry. The expression of nuclear factor E2-related factor 2 (Nrf2), glutamate-cysteine ligase catalytic subunit, and p62 was quantified using quantitative polymerase chain reaction and western blot. RESULTS: We found that HG inhibited cell proliferation, arrested cell cycle, and increased MMP in human Müller cells. Probucol activated the Nrf2/p62 pathway and upregulated the anti-apoptotic protein, Bcl2, and attenuated HG-mediated damage in Müller cells. CONCLUSIONS: Our results suggest that probucol may protect Müller cells from HG-induced damage through enhancing the Nrf2/p62 signaling pathway.


Assuntos
Células Ependimogliais , Probucol , Transdução de Sinais , Humanos , Células Ependimogliais/efeitos dos fármacos , Células Ependimogliais/metabolismo , Glucose/metabolismo , Glucose/farmacologia , Fator 2 Relacionado a NF-E2 , Probucol/farmacologia
13.
Phys Rev Lett ; 131(4): 041001, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37566838

RESUMO

We report a search for light dark matter produced through the cascading decay of η mesons, which are created as a result of inelastic collisions between cosmic rays and Earth's atmosphere. We introduce a new and general framework, publicly accessible, designed to address boosted dark matter specifically, with which a full and dedicated simulation including both elastic and quasielastic processes of Earth attenuation effect on the dark matter particles arriving at the detector is performed. In the PandaX-4T commissioning data of 0.63 tonne·year exposure, no significant excess over background is observed. The first constraints on the interaction between light dark matter generated in the atmosphere and nucleus through a light scalar mediator are obtained. The lowest excluded cross section is set at 5.9×10^{-37} cm^{2} for a dark matter mass of 0.1 MeV/c^{2} and mediator mass of 300 MeV/c^{2}. The lowest upper limit of η to the dark matter decay branching ratio is 1.6×10^{-7}.

14.
Phys Rev Lett ; 130(26): 261001, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37450819

RESUMO

We report the search results of light dark matter through its interactions with shell electrons and nuclei, using the commissioning data from the PandaX-4T liquid xenon detector. Low energy events are selected to have an ionization-only signal between 60 to 200 photoelectrons, corresponding to a mean nuclear recoil energy from 0.77 to 2.54 keV and electronic recoil energy from 0.07 to 0.23 keV. With an effective exposure of 0.55 tonne·year, we set the most stringent limits within a mass range from 40 MeV/c^{2} to 10 GeV/c^{2} for pointlike dark matter-electron interaction, 100 MeV/c^{2} to 10 GeV/c^{2} for dark matter-electron interaction via a light mediator, and 3.2 to 4 GeV/c^{2} for dark matter-nucleon spin-independent interaction. For DM interaction with electrons, our limits are closing in on the parameter space predicted by the freeze-in and freeze-out mechanisms in the early Universe.


Assuntos
Núcleo Celular , Elétrons
15.
Eur Urol ; 84(5): 449-454, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37500340

RESUMO

Previous analyses of KEYNOTE-426, an open-label, phase 3 randomized study, showed superior efficacy of first-line pembrolizumab plus axitinib to sunitinib in advanced clear cell renal cell carcinoma (ccRCC). We report results of the final protocol-prespecified analysis of KEYNOTE-426. Patients received pembrolizumab 200 mg intravenously every 3 wk plus axitinib 5 mg orally twice daily or sunitinib 50 mg orally once daily (4 wk per 6-wk cycle). The dual primary endpoints were overall survival (OS) and progression-free survival (PFS) as per RECIST v1.1 by a blinded independent central review. The secondary endpoints included objective response rate (ORR) and duration of response (DOR). The median study follow-up was 43 (range, 36-51) mo. Benefit with pembrolizumab plus axitinib versus sunitinib was maintained for OS (hazard ratio [HR], 0.73 [95% confidence interval {CI}, 0.60-0.88]), PFS (HR, 0.68 [95% CI, 0.58-0.80]), and ORR (60% vs 40%). The median DOR was 24 (range, 1.4+ to 43+) versus 15 (range, 2.3-43+) mo in the pembrolizumab plus axitinib versus the sunitinib arm. No new safety signals emerged. These results support pembrolizumab plus axitinib as a standard of care for patients with previously untreated advanced ccRCC. PATIENT SUMMARY: Extended results of KEYNOTE-426 support pembrolizumab plus axitinib as the standard of care for advanced clear cell renal cell carcinoma.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/patologia , Axitinibe/efeitos adversos , Sunitinibe/uso terapêutico , Seguimentos , Neoplasias Renais/patologia , Protocolos de Quimioterapia Combinada Antineoplásica
16.
Phys Rev Lett ; 130(2): 021802, 2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36706410

RESUMO

A search for interactions from solar ^{8}B neutrinos elastically scattering off xenon nuclei using PandaX-4T commissioning data is reported. The energy threshold of this search is further lowered compared with the previous search for dark matter, with various techniques utilized to suppress the background that emerges from data with the lowered threshold. A blind analysis is performed on the data with an effective exposure of 0.48 tonne year, and no significant excess of events is observed. Among the results obtained using the neutrino-nucleus coherent scattering, our results give the best constraint on the solar ^{8}B neutrino flux. We further provide a more stringent limit on the cross section between dark matter and nucleon in the mass range from 3 to 9 GeV/c^{2}.

17.
Phys Rev Lett ; 129(16): 161803, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36306747

RESUMO

Compared with the signature of dark matter elastic scattering off nuclei, the absorption of fermionic dark matter by nuclei opens up a new searching channel for light dark matter with a characteristic monoenergetic signal. In this Letter, we explore the 95.0-day data from the PandaX-4T commissioning run and report the first dedicated searching results of the fermionic dark matter absorption signal through a neutral current process. No significant signal was found, and the lowest limit on the dark matter-nucleon interaction cross section is set to be 1.5×10^{-50} cm^{2} for a fermionic dark matter mass of 40 MeV/c^{2} with 90% confidence level.

18.
Phys Rev Lett ; 129(16): 161804, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36306755

RESUMO

We report a search on sub-MeV fermionic dark matter absorbed by electrons with an outgoing active neutrino using the 0.63 tonne year exposure collected by the PandaX-4T liquid xenon experiment. No significant signals are observed over the expected background. The data are interpreted into limits to the effective couplings between such dark matter and the electron. For axial-vector or vector interactions, our sensitivity is competitive in comparison to existing astrophysical bounds on the decay of such a dark matter candidate into photon final states. In particular, we present the first direct detection limits for a vector (axial-vector) interaction which are the strongest in the mass range from 35 to 55 (25 to 45) keV/c^{2} in comparison to other astrophysical and cosmological constraints.

19.
Phys Rev Lett ; 128(17): 171801, 2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35570440

RESUMO

We report a novel search for the cosmic-ray boosted dark matter using the 100 tonne·day full dataset of the PandaX-II detector located at the China Jinping Underground Laboratory. With the extra energy gained from the cosmic rays, sub-GeV dark matter particles can produce visible recoil signals in the detector. The diurnal modulations in rate and energy spectrum are utilized to further enhance the signal sensitivity. Our result excludes the dark matter-nucleon elastic scattering cross section between 10^{-31} and 10^{-28} cm^{2} for dark matter masses from 0.1 MeV/c^{2} to 0.1 GeV/c^{2}, with a large parameter space previously unexplored by experimental collaborations.

20.
Appl Bionics Biomech ; 2022: 6113352, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35600845

RESUMO

Background: In recent years, the incidence of depression is on the rise. Our paper proposed to study the protective effects of Schisandrin on CORT-induced PC12 depressive cell model and the underlying mechanisms. Methods: The in vitro models of PC12 were established using corticosterone (CORT). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to screen the effective concentration of Schisandrin, and the models of PC12 were treated with low, medium, and high concentrations of Schisandrin. The cell activity of each group was detected by MTT assay. The LDH activity in each group of cells was detected by lactate dehydrogenase (LDH) kit. Apoptosis rate of each group was detected by Annexin V-FITC apoptosis assay kit. Mitochondrial membrane potential of each group of cells was detected by mitochondrial membrane potential kit. The protein expression levels of Caspase-3, Bax, and Bcl-2 in each group of cells were detected by western blot. Results: The treatment of Schisandrin significantly increased the cell viability in models of PC12. In addition, the results of LDH activity suggested that Schisandrin significantly reduced LDH content in models of PC12. Consistently, Schisandrin reduced the mitochondrial membrane potential of CORT-induced PC12 depressive cell model. Furthermore, Schisandrin effectively reduced the number of apoptotic cells and inhibited the expression of proapoptotic-related proteins (cleaved Caspase-3 and Bax) but increased the antiapoptotic-related protein (Bcl-2) in the models of PC12. Conclusions: Protective effects of Schisandrin on CORT-induced PC12 depressive cell model by inhibiting cells apoptosis in vitro.

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