Acoustic effects of speaker sex, speech sample, and Mandarin tone on vowel production of post-stroke spastic dysarthria.

INTRODUCTION: Vowel production in dysarthria tends to be centralized, which is affected by many factors. This study examined the acoustic effects of speaker sex, tones, and speech samples (including sustained vowels, syllables, and sentences) and their interactions on vowel production in Mandarin speakers with post-stroke spastic dysarthria. METHODS: 28 patients with post-stroke spastic dysarthria (18 males, 10 females) and 21 healthy speakers (11 males and 10 females) with no significant difference in sex and age with dysarthria were recruited. They were asked to read sustained vowels /a, i, u/, 12 syllables and 12 sentences containing three vowels in four tones (ba, bá, bǎ, bà, bi, bí, bǐ, bì, pu, pú, pǔ, pù). Multiple spectral and temporal acoustic metrics were analyzed. RESULTS: Results showed that regardless of the speech samples or tones, vowel production was more centralized in dysarthria than healthy controls, manifested as the decrease in F1 range, F2 range, vowel space area (VSA), and vowel articulation index (VAI). A similar performance was observed for male speakers compared to females, and vowel duration in males was shorter than females. F1 range, F2 range, VSA, VAI, and vowel duration were significantly different across speech samples and tones, decreasing in the order of vowel-syllable-sentence and T3-T2-T1-T4, respectively. Interactions of group, speaker sex, speech sample, and tone were more sensitive in VAI and vowel duration. CONCLUSION: VAI and vowel duration were recommended as the prior metrics to the assessment of vowel production. Specific influencing factors (speaker sex, speech sample, and tone) of vowel production need to be considered by speech and language pathologists in the assessment and rehabilitation.

Quantitative acoustic metrics of vowel production in mandarin-speakers with post-stroke spastic dysarthria.

Impairment of vowel production in dysarthria has been highly valued. This study aimed to explore the vowel production of Mandarin-speakers with post-stroke spastic dysarthria in connected speech and to explore the influence of gender and tone on the vowel production. Multiple vowel acoustic metrics, including F1 range, F2 range, vowel space area (VSA), vowel articulation index (VAI) and formant centralization ratio (FCR), were analyzed from vowel tokens embedded in connected speech produced. The participants included 25 clients with spastic dysarthria secondary to stroke (15 males, 10 females) and 25 speakers with no history of neurological disease (15 males, 10 females). Variance analyses were conducted and the results showed that the main effects of population, gender, and tone on F2 range, VSA, VAI, and FCR were all significant. Vowel production became centralized in the clients with post-stroke spastic dysarthria. Vowel production was found to be more centralized in males compared to females. Vowels in neutral tone (T0) were the most centralized among the other tones. The quantitative acoustic metrics of F2 range, VSA, VAI, and FCR were effective in predicting vowel production in Mandarin-speaking clients with post-stroke spastic dysarthria, and hence may be used as powerful tools to assess the speech performance for this population.

The combination of accent method and phonemic contrast: an innovative strategy to improve speech production on post-stroke dysarthria.

Introduction: Speech production includes segmental and suprasegmental features, which interact and cooperate with each other. Impaired speech production is common in individuals with post-stroke dysarthria. The commonly used phonemic contrast therapy and Accent Method in clinical practice can improve the segmental and suprasegmental aspects, respectively. This study aimed to explore the feasibility and immediate effectiveness of the combination of specific rhythm patterns of the Accent Method and phonemic contrast on speech production. Methods: Fifteen poststroke dysarthria patients (12 males and three females) first received accentuation task of three rhythm patterns (Largo-slow, Andante-medium, Allegro-fast) and later received speech task in appropriate rhythm patterns combined with phonemic contrast materials and non-phonemic contrast materials. Speech parameters were analyzed by considering speech clarity and prosody. Results: The results showed that the number of correct target syllables, sentence clarity, and standard deviation of intensity increased significantly, and the average length of pauses and abnormal pause times decreased significantly in Andante (medium) compared to other rhythms. The number of correct target syllables, sentence clarity, and standard deviation of intensity increased significantly compared with those in the non-phonemic contrast in Andante (medium). Conclusion: The combination of phonemic contrast and Accent Method was verified to have an immediate effect on speech production in Mandarin speakers with post-stroke dysarthria and could be further validated in other diseases with impaired speech production in the clinic in the future.

Catalytic conversion of rape straw into biofuels by direct non-thermal plasma modified HZSM-5.

Fresh HZSM-5 catalyst modification experiment was carried out on the direct non-thermal plasma (DNTP) reactor. The aim of this work was to study the effects of modified voltages on the physicochemical properties of HZSM-5 and its enhancement in biomass catalytic pyrolysis. The results showed that DNTP modification was performed at different voltages of 20 kV, 22 kV, 24 kV, compared with fresh HZSM-5, the effect of 22 kV voltage was preferably. H-22 had the largest specific surface area and mesoporous volume, and the total acid content added 17.02%. The biomass catalytic pyrolysis test was used to test the HZSM-5 catalytic activity after modification. The results showed that the catalyst obtained by the catalyst under 22 kV modified voltage had the highest monocyclic aromatic hydrocarbon selectivity of 40.55%.

Involvement of Phospholipase C in Photosynthesis and Growth of Maize Seedlings.

Phospholipase C is an enzyme that catalyzes the hydrolysis of glycerophospholipids and can be classified as phosphoinositide-specific PLC (PI-PLC) and non-specific PLC (NPC), depending on its hydrolytic substrate. In maize, the function of phospholipase C has not been well characterized. In this study, the phospholipase C inhibitor neomycin sulfate (NS, 100 mM) was applied to maize seedlings to investigate the function of maize PLC. Under the treatment of neomycin sulfate, the growth and development of maize seedlings were impaired, and the leaves were gradually etiolated and wilted. The analysis of physiological and biochemical parameters revealed that inhibition of phospholipase C affected photosynthesis, photosynthetic pigment accumulation, carbon metabolism and the stability of the cell membrane. High-throughput RNA-seq was conducted, and differentially expressed genes (DEGS) were found significantly enriched in photosynthesis and carbon metabolism pathways. When phospholipase C activity was inhibited, the expression of genes related to photosynthetic pigment accumulation was decreased, which led to lowered chlorophyll. Most of the genes related to PSI, PSII and TCA cycles were down-regulated and the net photosynthesis was decreased. Meanwhile, genes related to starch and sucrose metabolism, the pentose phosphate pathway and the glycolysis/gluconeogenesis pathway were up-regulated, which explained the reduction of starch and total soluble sugar content in the leaves of maize seedlings. These findings suggest that phospholipase C plays a key role in photosynthesis and the growth and development of maize seedlings.

The Adjustment of Membrane Lipid Metabolism Pathways in Maize Roots Under Saline-Alkaline Stress.

Plants are frequently confronted by diverse environmental stress, and the membrane lipids remodeling and signaling are essential for modulating the stress responses. Saline-alkaline stress is a major osmotic stress affecting the growth and development of crops. In this study, an integrated transcriptomic and lipidomic analysis was performed, and the metabolic changes of membrane lipid metabolism in maize (Zea mays) roots under saline-alkaline stress were investigated. The results revealed that phospholipids were major membrane lipids in maize roots, and phosphatidylcholine (PC) accounts for approximately 40% of the total lipids. Under 100 mmol NaHCO3 treatment, the level of PC decreased significantly (11-16%) and the parallel transcriptomic analysis showed an increased expression of genes encoding phospholipase A and phospholipase D/non-specific phospholipase C, which suggested an activated PC turnover under saline-alkaline stress. The plastidic galactolipid synthesis was also activated, and an abnormal generation of C34:6 galactolipids in 18:3 plants maize implied a plausible contribution from the prokaryotic pathway, which could be partially supported by the up-regulated expression of three putative plastid-localized phosphatidic acid phosphatase/lipid phosphate phosphatase. A comprehensive gene-metabolite network was constructed, and the regulation of membrane lipid metabolism under saline-alkaline stress in maize was discussed.

[The effect of immobilized laminin on titanium-oxide films to the behavior of human umbilical vein endothelial cells].

In this study, Ti-O films were synthesized using magnetron sputtering, and were pretreated using NaOH solution for improving surface activity from hydroxyl. The laminin(LN) biomacromolecule was further immobilized to the surface through an anminosilane linker. The surface characteristics of these samples were analyzed by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Atomic Force Microscopy and the contact angle method. Finally, human umbilical vein endothelial cells (HUVEC) were in vitro seeded to the modified and unmodified Ti-O films surface for evaluating the cell compatibility. Survey results suggested that the functional group of hydroxyl was presented onto Ti-O film surface after being pretreated, and laminin could be covalently immobilized to Ti-O film surface by anminosilane linker. The in vitro cell culture results reveal that the biological behaviors of ECs on biochemical modified Ti-O film surface are excellent. The adherence, growth and proliferation of ECs on laminin-immobilized surface were obviously improved when compared to control one. It implies that the laminin immobilizing is helpful to increasing the endothelialization of Ti-O films.

Identification of Fatty Acid Desaturases in Maize and Their Differential Responses to Low and High Temperature.

Plant fatty acid desaturases (FADs) catalyze the desaturation of fatty acids in various forms and play important roles in regulating fatty acid composition and maintaining membrane fluidity under temperature stress. A total of 30 FADs were identified from a maize genome, including 13 soluble and 17 membrane-bound FADs, which were further classified into two and five sub-groups, respectively, via phylogenetic analysis. Although there is no evolutionary relationship between the soluble and the membrane-bound FADs, they all harbor a highly conserved FA_desaturase domain, and the types and the distributions of conserved motifs are similar within each sub-group. The transcriptome analysis revealed that genes encoding FADs exhibited different expression profiles under cold and heat stresses. The expression of ZmFAD2.1&2.2, ZmFAD7, and ZmSLD1&3 were significantly up-regulated under cold stress; moreover, the expression of ZmFAD2.1&2.3 and ZmSLD1&3 were obviously down-regulated under heat stress. The co-expression analysis demonstrated close correlation among the transcription factors and the significant responsive FAD genes under cold or heat stress. This study helps to understand the roles of plant FADs in temperature stress responses.