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1.
Cancer Lett ; 524: 206-218, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34688842

RESUMO

Phosphatidylinositol 3-kinase (PI3K) δ-specific inhibitors have been approved for the therapy of certain types of B cell lymphoma (BCL). However, their clinical use is limited by the substantial toxicity and lack of efficacy in other types of BCL. Emerging evidence indicates that PI3Kα plays important roles in the progression of B cell lymphoma. In this study, we revealed that PI3Kα was important for the PI3K signaling and proliferation in BCL cells. A novel clinical PI3Kα-selective inhibitor CYH33 possessed superior activity against BCL compared to the marketed PI3Kα-selective inhibitor Alpelisib and PI3Kδ-selective inhibitor Idelalisib. Though CYH33 was able to inhibit PI3K/AKT signaling in tested BCL cells, differential activity against proliferation was observed. Transcriptome profiling revealed that CYH33 down-regulated "MYC-targets" gene set in sensitive but not resistant cells. CYH33 inhibited c-MYC transcription in sensitive cells, which was attributed to a decrease in acetylated H3 bound to the promoter and super-enhancer region of c-MYC. Accordingly, CYH33 treatment resulted in phosphorylation and proteasomal degradation of the histone acetyltransferase p300. An unbiased screening with drugs approved or in clinical trials for the therapy of BCL identified that the clinical BET (Bromodomain and Extra Terminal domain) inhibitor OTX015 significantly potentiated the activity of CYH33 against BCL in vitro and in vivo, which was associated with enhanced inhibition on c-MYC expression and induction of cell cycle arrest and apoptosis. Our findings provide the rationale of combined CYH33 with BET inhibitors for the therapy of B cell lymphoma.

2.
Pediatr Blood Cancer ; 69(1): e29344, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34550633

RESUMO

Twelvepatients without therapy-related leukemia were studied after completing TOP2 poison chemotherapy in a high-risk neuroblastoma regimen. One patient harbored an inv(11) that was a KMT2A rearrangement. The KMT2A-MAML2 transcript was expressed at low level. The patient was prospectively followed. The inv(11) was undetectable in ensuing samples. Leukemia never developed after a 12.8-year follow-up period. Enriched etoposide-induced TOP2A cleavage in the relevant MAML2 genomic region supports a TOP2A DNA damage mechanism. After completing TOP2 poison chemotherapies, covert KMT2A-R clones may occur in a small minority of patients; however, not all KMT2A rearrangements herald a therapy-related leukemia diagnosis.

3.
J Hazard Mater ; 423(Pt A): 127040, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34474366

RESUMO

Osmotic membrane bioreactors (OMBRs) have been applied to enhance removal of antibiotics, however, information on the effects of molecular structures on the behavior of antibiotics is still lacking. Herein, adsorption kinetics, transformation pathways, and membrane rejection mechanisms of OMBRs were investigated by adding two typical antibiotics (i.e., sulfadiazine, SDZ, and tetracycline hydrochloride, TC-HCl). 80.70-91.12% of TC-HCl was removed by adsorption and biodegradation, while 17.50-75.14% of SDZ was removed by membrane rejection; this depended on its concentration due to reduced electrostatic interactions and hydrophobic adsorption. The adsorption capacity of TC-HCl (i.e., 1.34±0.01 mg/g) was significantly higher than that of SDZ (i.e., 0.18±0.03 mg/g) due to enhanced π-π interactions, hydrogen bonding and improved electrostatic interactions. The abundant production of polysaccharide-like substances from TC-HCl biodegradation contributed to microbial metabolism and thus enhanced microbial function during TC-HCl biotransformation. The primary degradation pathways were determined by microbial function analysis, and the primary intermediates from TC-HCl degradation were less toxic than those from SDZ degradation due to the different reactions of amino groups. These results and the corresponding mechanism provide a theoretical foundation for the further development of OMBR technology for highly efficient treatment of antibiotic wastewater.

4.
Sci Rep ; 11(1): 21509, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34728758

RESUMO

We propose a highly tunable [Formula: see text] spin-polarized current generated in a spintronic device based on a Dirac semimetal (DSM) under a magnetic field, which can be achieved merely by controlling electrical parameters, i.e. the gate voltage, the chemical potential in the lead and the coupling strength between the leads and the DSM. These parameters are all related to the special properties of a semimetal. The spin polarized current generated by gate voltage is guaranteed by its semimetallic feature, because of which the density of state vanishes near Dirac nodes. The barrier controlled current results from the different distance of Weyl nodes generated by the Zeeman field. And the coupling strength controlled spin polarized current originates from the surface Fermi arcs. This DSM-based spintronic device is expected to be realized in [Formula: see text] experimentally.

5.
Asian J Androl ; 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34747725

RESUMO

We investigated the therapeutic effects of superoxide dismutase (SOD) from thermophilic bacterium HB27 on chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and its underlying mechanisms. A Sprague-Dawley rat model of CP/CPPS was prepared and then administered saline or Thermus thermophilic (Tt)-SOD intragastrically for 4 weeks. Prostate inflammation and fibrosis were analyzed by hematoxylin and eosin staining, and Masson staining. Alanine transaminase (ALT), aspartate transaminase (AST), serum creatinine (CR), and blood urea nitrogen (BUN) levels were assayed for all animals. Enzyme-linked immunosorbent assays (ELISA) were performed to analyze serum cytokine concentrations and tissue levels of malondialdehyde, nitric oxide, SOD, catalase, and glutathione peroxidase. Reactive oxygen species levels were detected using dichlorofluorescein diacetate. The messenger ribonucleic acid (mRNA) expression of tissue cytokines was analyzed by reverse transcription polymerase chain reaction (RT-PCR), and infiltrating inflammatory cells were examined using immunohistochemistry. Nuclear factor-κB (NF-κB) P65, P38, and inhibitor of nuclear factor-κBα (I-κBα) protein levels were determined using western blot. Tt-SOD significantly improved histopathological changes in CP/CPPS, reduced inflammatory cell infiltration and fibrosis, increased pain threshold, and reduced the prostate index. Tt-SOD treatment showed no significant effect on ALT, AST, CR, or BUN levels. Furthermore, Tt-SOD reduced inflammatory cytokine expression in prostate tissue and increased antioxidant capacity. This anti-inflammatory activity correlated with decreases in the abundance of cluster of differentiation 3 (CD3), cluster of differentiation 45 (CD45), and macrophage inflammatory protein 1α (MIP1α) cells. Tt-SOD alleviated inflammation and oxidative stress by reducing NF-κB P65 and P38 protein levels and increasing I-κBα protein levels. These findings support Tt-SOD as a potential drug for CP/CPPS.

6.
Artigo em Inglês | MEDLINE | ID: mdl-34757566

RESUMO

BACKGROUND: Left ventricular hypertrophy (LVH) is an independent prognostic factor for cardiovascular events and it can be detected by echocardiography in the early stage. In this study, we aim to develop a semi-automatic diagnostic network based on deep learning algorithms to detect LVH. METHODS: We retrospectively collected 1610 transthoracic echocardiograms, included 724 patients [189 hypertensive heart disease (HHD), 218 hypertrophic cardiomyopathy (HCM), and 58 cardiac amyloidosis (CA), along with 259 controls]. The diagnosis of LVH was defined by two experienced clinicians. For the deep learning architecture, we introduced ResNet and U-net++ to complete classification and segmentation tasks respectively. The models were trained and validated independently. Then, we connected the best-performing models to form the final framework and tested its capabilities. RESULTS: In terms of individual networks, the view classification model produced AUC = 1.0. The AUC of the LVH detection model was 0.98 (95% CI 0.94-0.99), with corresponding sensitivity and specificity of 94.0% (95% CI 85.3-98.7%) and 91.6% (95% CI 84.6-96.1%) respectively. For etiology identification, the independent model yielded good results with AUC = 0.90 (95% CI 0.82-0.95) for HCM, AUC = 0.94 (95% CI 0.88-0.98) for CA, and AUC = 0.88 (95% CI 0.80-0.93) for HHD. Finally, our final integrated framework automatically classified four conditions (Normal, HCM, CA, and HHD), which achieved an average of AUC 0.91, with an average sensitivity and specificity of 83.7% and 90.0%. CONCLUSION: Deep learning architecture has the ability to detect LVH and even distinguish the latent etiology of LVH.

7.
Mol Pain ; 17: 17448069211047863, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34761717

RESUMO

Lack of uricase leads to the high incidence of gout in humans and poultry, which is different from rodents. Therefore, chicken is considered to be one of the ideal animal models for the study of gout. Gout-related pain caused by the accumulation of urate in joints is one type of inflammatory pain, which causes damage to joint function. Our previous studies have demonstrated the crucial role of calcium-stimulated adenylyl cyclase subtype 1 (AC1) in inflammatory pain in rodents; however, there is no study in poultry. In the present study, we injected mono-sodium urate (MSU) into the left ankle joint of the chicken to establish a gouty arthritis model, and tested the effect of AC1 inhibitor NB001 on gouty arthritis in chickens. We found that MSU successfully induced spontaneous pain behaviors including sitting, standing on one leg, and limping after 1-3 h of injection into the left ankle of chickens. In addition, edema and mechanical pain hypersensitivity also occurred in the left ankle of chickens with gouty arthritis. After peroral administration of NB001 on chickens with gouty arthritis, both the spontaneous pain behaviors and the mechanical pain hypersensitivity were effectively relieved. The MSU-induced edema in the left ankle of chickens was not affected by NB001, suggesting a central effect of NB001. Our results provide a strong evidence that AC1 is involved in the regulation of inflammatory pain in poultry. A selective AC1 inhibitor NB001 produces an analgesic effect (not anti-inflammatory effect) on gouty pain and may be used for future treatment of gouty pain in both humans and poultry.

8.
Cancer Lett ; 526: 76-90, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34801597

RESUMO

Most prostate cancer (PCa)-related deaths are caused by progression to bone metastasis. Recently, the importance of extracellular vesicles (EVs) in pre-metastatic niche formation has been reported. However, whether and how tumor-derived EVs interact with bone marrow macrophages (BMMs) to release EV-delivered microRNAs to promote osteolysis and induce pre-metastatic niche formation for PCa bone metastasis remain unclear. Our in vitro and in vivo functional and mechanistic assays revealed that EV-mediated release of miR-378a-3p from tumor cells was upregulated in bone-metastatic PCa, maintaining low intracellular miR-378a-3p concentration to promote proliferation and MAOA-mediated epithelial-to-mesenchymal transition. Moreover, miR-378a-3p enrichment in tumor-derived EVs was induced by hnRNPA2B1 (a transfer chaperone) overexpression. After tumor-derived EVs were taken in by BMMs, enriched miR-378a-3p promoted osteolytic progression by inhibiting Dyrk1a to improve Nfatc1 (an osteolysis-related transcription factor) nuclear translocation, to activate the expression of downstream target gene Angptl2. As a feedback, increased Angptl2 secretion into the tumor environment promoted PCa progression. In conclusion, tumor-derived miR-378a-3p-containing EVs play a significant role in PCa bone metastasis by activating the Dyrk1a/Nfatc1/Angptl2 axis in BMMs to induce osteolytic progression, making miR-378a-3p a potential predictor of metastatic PCa. Reducing the release of miR-378a-3p-containing EVs or inhibiting the recruitment of miR-378a-3p into EVs can be a therapeutic strategy against PCa metastasis.

9.
Neuropharmacology ; 204: 108895, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34813859

RESUMO

Social memory is the ability to discriminate familiar conspecific from the unknown ones. Prefrontal neurons are essentially required for social memory, but the mechanism associated with this regulation remains unknown. It is also unclear to what extent the neuronal representations of social memory formation and retrieval events overlap in the prefrontal cortex (PFC) and which event drives social memory strength. Here we asked these questions by using a repeated social training paradigm for social recognition in FosTRAP mice. We found that after 4 days' repeated social training, female mice developed stable social memory. Specifically, repeated social training activated more cells that were labeled with tdTomato during memory retrieval compared with the first day of memory encoding. Besides, combining TRAP with c-Fos immunostaining, we found about 30% of the FosTRAPed cells were reactivated during retrieval. Moreover, the number of retrieval-induced but not first-day encoding-induced tdTomato neurons correlates with the social recognition ratio in the prelimbic but not other subregions. The activated cells during the retrieval session also showed increased NMDA receptor-mediated synaptic transmission compared with that in non-labeled pyramidal neurons. Blocking NMDA receptors by MK-801 impaired social memory but not sociability. Therefore, our results reveal that repetitive training elevates mPFC involvement in social memory retrieval via enhancing NMDA receptor-mediated synaptic transmission, thus rendering stable social memory.

10.
J Phys Condens Matter ; 34(7)2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34753119

RESUMO

A nodal ring semimetal (NRSM) can be driven to a spin-polarized NRSM or a spin-polarized Weyl semimetal (WSM) by a high-frequency electromagnetic field. We investigate the conditions in realizing these phases and propose a switchable spin-polarized currents generator based on periodically driven NRSMs. Both bulk and surface polarized currents are investigated. The polarization of bulk current is sensitive to the amplitude of the driving field and robust against the direction and polarization of the driving, the opaqueness of the lead-device interface and the misalignment between the nodal ring and the interface, which provides sufficient flexibility in manipulating the devices. Similar switchable polarized surface currents are also expected, which is contributed by the Fermi arc surface state associated with the WSM phases. The generation of polarized currents and the polarization switching effect offer opportunities to design periodic driving controlled topological spintronics devices based on NRSMs.

11.
Opt Express ; 29(21): 34781-34796, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34809260

RESUMO

This paper proposes a passive optical brightening element design, a non-axisymmetric freeform lens (NAFL), arranged and assembled on a traditional traffic sign. NAFL is the first optical design which can effectively solve the traffic problem that direct sunlight affects the driver's inability to look directly at the traffic sign. The NAFL can converge the sunlight behind the traffic sign and diverge forward to 150 meters away. In this way, the NAFL array combinations on the traffic sign can directly rely on sunlight as image information pixels. According to the simulation, the optical efficiency of the NAFL can be as high as 81.5%. Besides, the angular tolerance is also analyzed to evaluate the working hours of the NAFL. Finally, we made the prototype and proved that such passive brightening components could effectively improve the traffic sign's visibility in harsh sunlight.

12.
STAR Protoc ; 2(4): 100901, 2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34816126

RESUMO

Eukaryotic RNAs can be modified with a non-canonical 5' nicotinamide adenine dinucleotide (NAD+) cap. NAD-seq identifies transcriptome-wide NAD+ capped RNAs. NAD-seq takes advantage of click chemistry to allow the capture of NAD+ capped RNAs. Unlike other approaches, NAD-seq does not require DNA synthesis on beads, but this technique uses full NAD+ capped transcripts eluted from beads as the substrates for strand-specific RNA sequencing library preparation. For complete details on the use and execution of this protocol, please refer to Yu et al. (2021).

13.
Front Endocrinol (Lausanne) ; 12: 722674, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34721291

RESUMO

Objectives: The CDK5 regulatory subunit-associated protein 1-like 1 (CDKAL1) contributes to islet ß-cell function and insulin secretion by inhibiting the activation of CDK5. The current studies on the relationship between CDKAL1 polymorphisms rs7756992 A>G and rs7754840 C>G and the risk of gestational diabetes mellitus (GDM) have drawn contradictory conclusions. Materials and Methods: A meta-analysis with a fixed- or random-effects model was conducted to estimate the correlation between studied CDKAL1 polymorphisms and GDM risk with the summary odds ratio (OR) and 95% confidence interval (CI). In addition, trial sequential analysis (TSA) and false-positive report probability (FPRP) analysis were performed to confirm the study findings. Results: A total of 13,306 subjects were included in the present study. Meta-analysis results showed that the variant heterozygous and homozygous genotypes of the two polymorphisms were associated with increased GDM risk in comparison with the wild-type AA genotype (AG vs. AA: OR = 1.23, 95% CI = 1.08, 1.41, p = 0.002; GG vs. AA: OR = 1.47, 95% CI = 1.05, 2.05, p = 0.024 for rs7756992; and CG vs. GG: OR = 1.36, 95% CI = 1.13, 1.65, p = 0.002; CC vs. GG: OR = 1.76, 95% CI = 1.37, 2.26, p < 0.001 for rs7754840). The TSA confirmed a significant association between rs7754840 and the susceptibility to GDM because the cumulative Z-curve crossed both the conventional cutoff value and the TSA boundaries under the heterozygote and homozygote models. Conclusions: This study supported the finding that rs7756992 and rs7754840 are associated with susceptibility to GDM. However, further functional studies are warranted to clarify the mechanism.

14.
Theor Appl Genet ; 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34837123

RESUMO

KEY MESSAGE: Analysis of drought-related genes in cassava shows the involvement of MeSPL9 in drought stress tolerance and overexpression of a dominant-negative form of this gene demonstrates its negative roles in drought stress resistance. Drought stress severely impairs crop yield and is considered a primary threat to food security worldwide. Although the SQUAMOSA promoter binding protein-like 9 (SPL9) gene participates extensively in numerous developmental processes and in plant response to abiotic stimuli, its role and regulatory pathway in cassava (Manihot esculenta) response to the drought condition remain elusive. In the current study, we show that cassava SPL9 (MeSPL9) plays negative roles in drought stress resistance. MeSPL9 expression was strongly repressed by drought treatment. Overexpression of a dominant-negative form of miR156-resistant MeSPL9, rMeSPL9-SRDX, in which a 12-amino acid repressor sequence was fused to rMeSPL9 at the C terminus, conferred drought tolerance without penalizing overall growth. rMeSPL9-SRDX-overexpressing lines not only exhibited increased osmoprotectant metabolites including proline and anthocyanin, but also accumulated more endogenous jasmonic acid (JA) and soluble sugars. Transcriptomic and real-time PCR analysis suggested that differentially expressed genes were involved in sugar or JA biosynthesis, signaling, and metabolism in transgenic cassava under drought conditions. Exogenous application of JA further confirmed that JA conferred improved drought resistance and promoted stomatal closure in cassava leaves. Taken together, our findings suggest that MeSPL9 affects drought resistance by modulating protectant metabolite levels and JA signaling, which have substantial implications for engineering drought tolerant crops.

15.
J Neurosci ; 2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34844989

RESUMO

Neuronal activity in the prefrontal cortex (PFC) controls dominance hierarchies in groups of animals. Dopamine (DA) strongly modulates PFC activity mainly through D1 receptors (D1Rs) and D2 receptors (D2Rs). Still, it is unclear how these two subpopulations of DA receptor-expressing neurons in the PFC regulate social dominance hierarchy. Here, we demonstrate distinct roles for prefrontal D1R- and D2R-expressing neurons in establishing social hierarchy, with D1R+ neurons determining dominance whereas D2R+ neurons for the subordinate. Ex vivo whole-cell recordings revealed that the dominant status of male mice correlates with rectifying AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor transmission and stronger excitatory synaptic strength onto D1R+ neurons in PFC pyramidal neurons. In contrast, the submissive status is associated with higher neuronal excitability in D2R+ neurons. Moreover, simultaneous manipulations of synaptic efficacy of D1R+ neurons in dominant male mice and neuronal excitability of D2R+ neurons of their male subordinates switch their dominant-subordinate relationship. These results reveal that prefrontal D1R+ and D2R+ neurons have distinct but synergistic functions in the dominance hierarchy, and DA-mediated regulation of synaptic strengths acts as a powerful behavioral determinant of intermale social rank.Significance StatementDominance hierarchy exists widely among animals who confront social conflict. Studies have indicated that social status largely relies on the neuronal activity in the prefrontal cortex, but how dopamine influences social hierarchy via subpopulation of prefrontal neurons is still elusive. Here, we explore the cell-type-specific role of dopamine receptor-expressing prefrontal neurons in the dominance-subordinate relationship. We found that the synaptic strength of D1 receptor-expressing neurons determines the dominant status, while hyperactive D2-expressing neurons are associated with the subordinate status. These findings highlight how social conflicts recruit distinct cortical microcircuits to drive different behaviors and reveal how D1- and D2-receptor enriched neurocircuits in the prefrontal cortex establish a social hierarchy.

16.
Bioconjug Chem ; 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34846126

RESUMO

Bioorthogonal chemistry is a set of methods using the chemistry of non-native functional groups to explore and understand biology in living organisms. In this review, we summarize the most common reactions used in bioorthogonal methods, their relative advantages and disadvantages, and their frequency of occurrence in the published literature. We also briefly discuss some of the less common but potentially useful methods. We then analyze the bioorthogonal-related publications in the CAS Content Collection to determine how often different types of biomolecules such as proteins, carbohydrates, glycans, and lipids have been studied using bioorthogonal chemistry. The most prevalent biological and chemical methods for attaching bioorthogonal functional groups to these biomolecules are elaborated. We also analyze the publication volume related to different types of bioorthogonal applications in the CAS Content Collection. The use of bioorthogonal chemistry for imaging, identifying, and characterizing biomolecules and for delivering drugs to treat disease is discussed at length. Bioorthogonal chemistry for the surface attachment of proteins and in the use of modified carbohydrates is briefly noted. Finally, we summarize the state of the art in bioorthogonal chemistry and its current limitations and promise for its future productive use in chemistry and biology.

17.
Lancet Microbe ; 2(10): e518-e526, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34617068

RESUMO

Background: Direct bronchial spread of tuberculosis was extensively described in pre-antibiotic human pathology literature but this description has been overlooked in the post-antibiotic era, in which most pathology data come from animal models that emphasise the granuloma. Modern techniques, such as [18F]2-fluoro-2-deoxy-D-glucose (FDG) PET-CT scans, might provide further insight. Our aim was to understand normal early tuberculosis resolution patterns on pulmonary PET-CT scans in treated patients with tuberculosis who were subsequently cured. Methods: In this observational analysis, we analysed data from PredictTB, an ongoing, prospective, randomised clinical trial that examined sequential baseline and week 4 FDG-PET-CT scans from participants successfully treated (sputum culture negative 18 months after enrolment) for drug-susceptible pulmonary tuberculosis in South Africa and China. Participants who were aged 18-75 years, GeneXpert MTB/RIF positive for tuberculosis and negative for rifampicin resistance, had not yet started tuberculosis treatment, had not been treated for active tuberculosis within the previous 3 years, and met basic safety laboratory criteria were included and participants with diabetes, HIV infection, or with extrapulmonary tuberculosis including pleural tuberculosis were excluded. Scans were assessed by two readers for the location of tuberculosis lesions (eg, cavities and consolidations), bronchial thickening patterns, and changes from baseline to week 4 of treatment. Findings: Among the first 124 participants (enrolled from June 22, 2017, to Sept 27, 2018) who were successfully treated, 161 primarily apical cavitary lesions were identified at baseline. Bronchial thickening and inflammation linking non-cavitary consolidative lesions to cavities were observed in 121 (98%) of 124 participants' baseline PET-CT scans. After 4 weeks of treatment, 21 (17%) of 124 participants had new or expanding lesions linked to cavities via bronchial inflammation that were not present at baseline, particularly participants with two or more cavities at baseline and participants from South Africa. Interpretation: In participants with pulmonary tuberculosis who were subsequently cured, the location of cavitary and non-cavitary lesions at baseline and new lesions at week 4 of treatment suggest a cavitary origin of disease and bronchial spread through the lungs. Bronchial spread from cavities might play a larger role in the spread of pulmonary tuberculosis than has been appreciated. Elucidating cavity lesion dynamics and Mycobacterium tuberculosis viability within cavities might better explain treatment outcomes and why some patients are cured and others relapse. Funding: Bill & Melinda Gates Foundation, European and Developing Countries Clinical Trials Partnership, China Ministry of Science and Technology, National Natural Science Foundation of China, and National Institutes of Health. Translations: For the Chinese, Afrikaans and Xhosa translations of the abstract see Supplementary Materials section.

18.
Anal Chim Acta ; 1184: 339053, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34625259

RESUMO

Laser-induced breakdown spectroscopy (LIBS) is a promising multi-elemental analysis technique and has the advantages of rapidness and minimal sample preparation. In traditional LIBS measurement, sample spectra are generally collected based on a single set of fixed experimental parameters, such as laser energy and delay time. When samples have the same main components and similar component concentrations, the difference in their spectral intensities becomes less obvious. This can lower the sensitivity of LIBS measurement and pose a threat to the accuracy and robustness of LIBS qualitative analysis. In this work, we propose a new method to increase the spectral difference between similar samples, namely multiple-setting spectra. For each sample, it adopts different sets of experimental parameters and obtains a group of spectra to increase the fingerprint spectral information. The effectiveness of the proposed method is theoretically verified and then tested on 11 similar coal samples. Specifically, the sample spectra were collected with different laser energy and delay time, and processed by principal component analysis (PCA) and Davies-Bouldin index (DBI). The results show that the use of multiple-settings spectra can significantly improve the sample discrimination accuracy from 81.8% to 96.4%. In addition, the proposed method can maintain the efficiency and cost of LIBS measurement.


Assuntos
Lasers , Análise de Componente Principal , Análise Espectral
19.
ACS Nano ; 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34664931

RESUMO

Generating terahertz waves using thin-layered materials holds great potential for the realization of integrated terahertz devices. However, previous studies have been limited by restricted radiation intensity and finite efficiency. Exploiting materials with higher efficiency for terahertz emission has attracted increasing interest worldwide. Herein, with visible-light excitation, a thin-layered GaTe film is demonstrated to be a promising emitter of terahertz radiation induced by the shift-current photovoltaic effect. Through theoretical calculations, a transient charge-transfer process resulting from the asymmetric structure of GaTe is shown to be the origin of an ultrafast shift current. Furthermore, it was found that the amplitude of the resulting terahertz signals can be manipulated by both the fluence of the pump laser and the orientation of the sample. Such high emission efficiency from the shift current indicates that the layered material (GaTe) is an excellent candidate for photovoltaics and terahertz emitters.

20.
J Biomater Sci Polym Ed ; : 1-16, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34641765

RESUMO

Cationic polysaccharides have shown excellent ability of nucleic acids delivery. However, cationic curdlan derivatives with high degree of amination cause damage to the cell membrane and induce considerable cytotoxicity, limiting their in vivo application. Herein, we synthesized PEGylated 6-amino-6-deoxy-curdlan derivatives containing cleavable disulfide bonds. The resulting polymers (denote 6AC-2S PEGx) not only showed high affinity to siRNA but also exhibited significantly decreased cytotoxicity and hemolysis effect, while showing remarkable in vitro transfection efficiency. In vivo study demonstrated that 6AC-2S PEG40, which had a lower LD50 value than that of 6AC-100, did not cause liver damage, as the i.v. injection of 6AC-2S PEG40 to mouse did not increase serum level of ALT/AST. Furthermore, tissue distribution results showed that 6AC-2S PEG40 successfully delivered siRNA to liver, lung and spleen. Collectively, our data confirmed that PEGylation can increase the biocompatibility of cationic curdlan derivatives, which is a promising carrier for nucleic acid therapeutics.

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