Endangered language generally has low-resource characteristics, as an immaterial cultural resource that cannot be renewed. Automatic speech recognition (ASR) is an effective means to protect this ...language. However, for low-resource language, native speakers are few and labeled corpora are insufficient. ASR, thus, suffers deficiencies including high speaker dependence and over fitting, which greatly harms the accuracy of recognition. To tackle the deficiencies, the paper puts forward an approach of audiovisual speech recognition (AVSR) based on LSTM-Transformer. The approach introduces visual modality information including lip movements to reduce the dependence of acoustic models on speakers and the quantity of data. Specifically, the new approach, through the fusion of audio and visual information, enhances the expression of speakers' feature space, thus achieving the speaker adaptation that is difficult in a single modality. The approach also includes experiments on speaker dependence and evaluates to what extent audiovisual fusion is dependent on speakers. Experimental results show that the CER of AVSR is 16.9% lower than those of traditional models (optimal performance scenario), and 11.8% lower than that for lip reading. The accuracy for recognizing phonemes, especially finals, improves substantially. For recognizing initials, the accuracy improves for affricates and fricatives where the lip movements are obvious and deteriorates for stops where the lip movements are not obvious. In AVSR, the generalization onto different speakers is also better than in a single modality and the CER can drop by as much as 17.2%. Therefore, AVSR is of great significance in studying the protection and preservation of endangered languages through AI.
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In this paper, a compression behavior classification system (CBCS) for direct compression (DC) pharmaceutical powders is presented. Seven descriptors from a series of compression ...models for powder compressibility, compactibility and tabletability analysis were included in the CBCS. A new tabletability index d was proposed to differentiate three categories of tensile strength (TS) vs. pressure relationships, and its physical meaning was explained thoroughly. 130 materials containing diverse pharmaceutical excipients and natural product powders (NPPs) were fully characterized and were compiled into an in-house developed material library, in which 70 materials with potential DC applications were used to justify the effectiveness of the CBCS. Principle component analysis (PCA) was used to uncover the latent structure of compression variables. Moreover, partial least squares (PLS) regression models are established in prediction of both tablet TS and solid fraction (SF) based on the raw materials’ physical characteristics, the compression behavior indices and the compression force. The obtained scores and loadings are used to group the materials and the compression variables, respectively. Different categories of tabletability for DC powders were clearly clustered along two orthogonal directions pointing to the index d and the compression force. Finally, a multi-objective design space was identified under the latent variable space, summarizing the operationally possible region for both material properties and compression pressure required in DC tablet formulation design.
MicroRNAs (miRNAs) are small non-coding RNAs about 22 nucleotides in length, which play an important role in gene regulation of both eukaryotes and viruses. They can promote RNA cleavage and repress ...translation via base-pairing with complementary sequences within mRNA molecules.
Human cytomegalovirus (HCMV) encodes a large number of miRNAs that regulate transcriptions of both host cells and themselves to favor viral infection and inhibit the host's immune response. To date, ~ 26 mature HCMV miRNAs have been identified. Nevertheless, their roles in viral infection are ambiguous, and the mechanisms have not been fully revealed. Therefore, we discuss the methods used in HCMV miRNA research and summarize the important roles of HCMV miRNAs and their potential mechanisms in infection.
To study the miRNAs encoded by viruses and their roles in viral replication, expression, and infection will not only contribute to the planning of effective antiviral therapies, but also provide new molecular targets for the development of antiviral drugs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Berberine (BBR) is an effective cholesterol-lowering drug. Although gut microbiota has been implicated in the pharmacological activities of BBR, little evidence exists on the specific species of gut ...microbiota involved in its therapeutic effects, nor on linking gut bacteria to its recognized hypercholesterolemia-alleviating mechanism–upregulation of the low-density lipoprotein receptor (LDLR) in the liver. The present study was performed to identify the specific species of gut microbiota involved in the anti-hyperlipdemic effect of BBR, and interpret its mechanism through linking the gut microbiota and LDLR. The BBR-enriched gut bacterial species were identified by whole genome shotgun sequencing. Pure cultured B. producta was orally administered to C57BL/6 mice to evaluate its anti-hyperlipdemic effect. The LDLR-upregulating effect of B. producta was evaluated both in vitro and in vivo. Orally administration of BBR (200 mg/kg) decreased serum and liver lipid levels in HFD-induced hyperlipidemic mice. Microbiome analysis indicated that Blautia was closely associated with BBR’s lipid-modulating activities. Further analysis revealed that BBR selectively promoted the growth of Blautia producta. Orally treatment of HFD mice with live B. producta reduced obesity and alleviated hyperlipidemia. Notably, the B. producta significantly increased LDLR expression in the liver, and its spent culture supernatant upregulated the LDLR level and promoted LDL uptake by HepG2 cells. Simultaneously, B. producta also linked butyrate-producing and bile salt hydrolase (BSH)-inhibiting effect of BBR. The gut microbiota, especially B. producta, may confers the hypercholesterolemia-alleviating effects of berberine. B. producta represents a novel probiotic that may be used for the treatment of dyslipidemia.
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The gut microbiota plays a key role in the maintenance of human health and mediates the beneficial effects of natural products including polyphenols. Previous studies have demonstrated that the ...polyphenol-rich Pandanus tectorius fruit extract (PTF) was effective in ameliorating high-fat diet (HFD)-induced hyperlipidaemia, and polyphenols can significantly change the structure of the gut microbiota. Purpose: In this study, we assessed whether the modulation of the gut microbiota plays a key role in the PTF-induced anti-hyperlipidaemic effects.
Male C57BL/6 J mice were induced with hyperlipidaemia by consuming a high-fat diet (HFD) for 4 weeks. Then, the mice were orally administered PTF, antibiotics (ampicillin+ norfloxacin), PTF+antibiotics or vehicle for another 6 weeks. Body weights and 24-h food intake were assessed weekly. At the end of the experiment, fresh stools were collected for 16S RNA pyrosequencing, and blood and liver and fat tissue were collected for pharmacological analysis.
PTF was effective in ameliorating high-fat diet (HFD)-induced hyperlipidaemia and significantly changed the structure of the gut microbiota. However, the anti-hyperlipidaemic effect of PTF was not influenced by the co-treatment with antibiotics (ampicillin+norfloxacin). A microbiological analysis of the gut microbiotas revealed that PTF selectively enhanced the relative abundance of Lactobacillus and decreased the relative abundance of Bacteroides and Alistipes. A correlation analysis between biochemical indexes and individual taxon showed that Lactobacillus was negatively associated with serum lipids and glucose while Bacteroides and Alistipes were positively associated with serum lipids and glucose. The modulatory effect of PTF on Lactobacillus, Bacteroides and Alistipes was not disturbed by the administration of antibiotics.
These results demonstrated that the polyphenol-rich PTF as a unique gut microbiota modulating agent and highlighted the richness of Lactobacillus and the decreased abundance of Bacteroides and Alistipes as an effective indicator of the therapeutic effect of medicinal foods on hyperlipidaemia.
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Akkermansia spp. plays important roles in maintenance of host health. Increasing evidence reveals that berberine (BBR) may exert its pharmacological effects via, at least partially, promotion of ...Akkermansia spp. However, how BBR stimulates Akkermansia remains largely unknown.
In this study, we investigated the mechanism underlying the Akkermansia-promoting effect of BBR.
The effect of BBR on Akkermansia was assessed in BBR-gavaged mice and direct incubation. The influence of BBR on intestinal mucin production was determined by alcian-blue staining and real-time PCR. The feces were analysis by gas chromatography–time-of-flight mass spectrometry (GC-TOF/MS) metabolomics. The role of polyamines in BBR-elicited mucin secretion and Akkermansia growth was evaluated by administration of difluoromethylornithine (DFMO) in mice.
Gavage of BBR dose-dependently and time-dependently increased the abundance of Akkermansia in mice. However, it did not stimulate Akkermansia growth in direct incubation, suggesting that BBR may promote Akkermansia in a host-dependent way. Oral administration of BBR significantly increased the transcription of mucin-producing genes and mucin secretion in colon. Untargeted metabolomics analysis showed that BBR increased polyamines production in feces which are known to stimulate goblet cell proliferation and differentiation, but treatment with eukaryotic polyamine synthase inhibitor DFMO did not abolish the stimulating effect of BBR on mucin secretion and Akkermansia growth, indicating that the gut bacteria-derived but not the host-derived polyamines may involve in the BBR-promoted Akkermansia growth.
Our results reveal that BBR is a promising prebiotic for Akkermansia, and it promotes Akkermansia growth via stimulating mucin secretion in colon.
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•Berberine is a potent prebiotic for Akkermansia.•Berberine promotes Akkermansia growth via stimulating mucin secretion in host intestine.•The research puts forward a novel insight into the modulation of functional gut microbes.
The membrane emulsification technique enables the self-assembly of cellulose nanocrystals (CNCs) confined within a spherical geometry for large-scale production. The resulting solid microspheres show ...long-range ordering with chiral nematic structures, and this fascinating hierarchical architecture can even be transferred to mesoporous carbon or silica microparticles by a sacrificial template method.
The membrane emulsification technique enables the self-assembly of cellulose nanocrystals (CNCs) confined within a spherical geometry for large-scale production.
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•Gut microbiota plays a crucial role in the anti-hyperlipidemic effect of Momordica charantia fruit (MC).•Transplantation of gut flora from MC-treated donor mice significantly ...decreased serum lipids.•Modulating gut microbes and increasing SCFAs may be a key mechanism for the lipid-lowering effect of M. charantia fruit.
The bitter melon (Momordica charantia) is a medical food with well-documented hypoglycemic and anti-hyperlipidemic activities. Previous studies showed that the M. charantia fruit (MC) could modulate the gut microbiota, but whether this modulation is essential for MC’s pharmacological effects is largely unknown. Here, we assessed the causality of gut microbes in MC-elicited anti-hyperlipidemic effects for the first time. Oral administration of MC significantly prevented hyperlipidemia, but this amelioration substantially diminished when co-treated with antibiotics. Transplantation of gut flora from MC-treated donor mice also significantly decreased serum lipids. The microbiological analysis revealed that MC moderately increased diversity and shifted the overall structure of gut microbiota. It selectively enhanced the relative abundance of short-chain fatty acid (SCFAs)-producing genera and increased fecal SCFAs content. These results demonstrate that M. charantia fruit (MC) may exert an anti-hyperlipidemic effect through modulating gut microbes and increasing SCFAs production.
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Inhalable particles containing amorphous form of drugs or excipients may absorb atmospheric moisture, causing powder aggregation and recrystallization, adversely affecting powder ...dispersion and lung deposition. The present study aims to explore hydrophobic amino acids for protection against moisture in spray-dried amorphous powders, using disodium cromoglycate (DSCG) as a model drug.
DSCG powders were produced by co-spray drying with isoleucine (Ile), valine (Val) and methionine (Met) in various concentrations (10, 20 and 40%w/w). Particle size distribution and morphology were measured by laser diffraction and scanning electron microscopy (SEM). Physiochemical properties of the powders were characterized by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic vapor sorption (DVS). Particle surface chemistry was analyzed by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). In vitro aerosolization performance was evaluated by a next generation impactor (NGI) after the powders were stored at 60% or 75% relative humidity (RH) for one month and three months.
Ile, Val and Met significantly reduced the deleterious effect of moisture on aerosol performance, depending on the amount of amino acids in the formulation. Formulations containing 10% or 20% of Ile, Val and Met showed notable deterioration in aerosol performance, with fine particle fraction (FPF) reduced by 6–15% after one-month storage at both 60% and 75% RH. However, 40% Ile was able to maintain the aerosol performance of DSCG stored at 75% RH for one month, while the FPF dropped by 7.5% after three months of storage. In contrast, 40% Val or Met were able to maintain the aerosol performance at 60% RH storage but not at 75% RH. At 40%w/w ratio, these formulations had particle surface coverage of 94.5% (molar percent) of Ile, 87.1% of Val and 84.6% of Met, respectively, which may explain their moisture protection effects.
Ile, Val and Met showed promising moisture protection effect on aerosol performance. The results broaden the understanding on the use of hydrophobic amino acids as an excipient for long-term storage of inhalation powders formulations that are hygroscopic.
Reversible self-assembly of nanoparticles into ordered structures is essential for both fundamental study and practical applications. Although extensive work has been conducted, the demand for ...simple, cheap, reversible, and versatile ordering methods is still a central issue in current nanoscience and nanotechnology. Here we report a reversible and precise self-assembly of nanoparticles through a linker-free and fast approach by manipulating the interparticle forces, e.g., van der Waals (VDW) force and electrostatic force. Because VDW force is nondirectional, an oriented interaction is achieved to induce the directional binding of nanoparticles utilizing the Janus nanostructure. An effective sol–gel approach has been developed to synthesize metal-organosilica Janus nanoparticles. Dimers and trimers can be obtained by tuning the steric hindrance. After assembly, “hot-spots” can be generated between adjacent nanoparticles, and dramatic enhancement has been observed in surface-enhanced Raman scattering. The present strategy overcomes several limitations of existing approaches and allows the controlled assembly of small particles into various structures.