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The purpose of this study was to investigate university students' perceptions of social media as a learning resource (SM-LR) in China and the USA in terms of their attitudes, perceived usefulness and behavioral intentions. An instrument used for this study was adapted from a prior validated survey based on the Technology Acceptance Model. The sample population consisted of 241 respondents from universities in China and the USA. The results suggested that most respondents (>75%) from each nation had used social media for learning purposes and that they shared similar understandings and definitions of social media. However, significant differences by nation were found concerning students' attitudes, perceived usefulness and behavioral intentions. Most respondents from China were more positive about SM-LR than their counterparts from the USA. Also, respondents who had previously used social media for learning were more positive about SM-LR. No correlations were found between students' self-reported academic performance and their attitudes, perceived usefulness, or behavioral intentions. Proposed areas of future research are discussed. [ABSTRACT FROM AUTHOR]

This work presents a systematic investigation of the spectroscopic properties at anharmonic force fields of ground electronic state ( X ˜ 1 A 1 ) of LiNH2, which are calculated using second-order Møller-Plesset perturbation theory (MP2) and density functional theory (DFT) with hybrid GGA and meta-hybrid GGA (M06-2X) exchange-correlation functional. Two high angular momentum basis sets of 6-311+g (2d, p) and 6-311++g (3df, 2pd) are used. The equilibrium geometries, ground-state rotational constants, harmonic frequencies, and quartic and sextic centrifugal distortion constants of LiNH2 are calculated and compared with corresponding experimental or theoretical data. The predicted accuracy of the calculated constants has been confirmed by analyzing the deviations with respect to experiment. In addition, the anharmonic constants, vibration-rotation interaction constants, force constants, and Coriolis coupling constants of LiNH2 are firstly obtained. The infrared spectrum is predicted and together with the first prediction on the higher-order anharmonic constants contributes to a better understanding of the vibrational and rotational characteristics of LiNH2, thus revealing its internal structure. [ABSTRACT FROM AUTHOR]

This paper mainly discusses the application of speech system based on deep learning in online music learning system. Firstly, this paper introduces the concept and principle of deep learning technology, studies the basic principle of twin network and the research status of target tracking, and discusses how to apply the twin network target tracking technology to the music Internet course learning system. Then, it introduces the basic principle of voice data system and its application in the field of music learning and discusses how to apply voice data system to music Internet course learning system. Then, aiming at the problems existing in the online music learning system, the deep learning technology is used to realize the voice interaction solution. In this paper, a framework of music learning system based on twin network target tracking and speech data system is proposed. By constructing speech recognition model and speech synthesis model based on deep learning, the system can realize various functions such as music recognition, melody tracking, rhythm perception, and speech interaction. Finally, the feasibility and effectiveness of the scheme are proved through experimental verification, which provides a useful reference for the further development of online music learning system. [ABSTRACT FROM AUTHOR]

Circadian rhythms modulate many physiologic processes and behaviors. Therefore, their disruption causes a variety of potential adverse effects in humans and animals. Circadian disruption induced by constant light exposure has been discovered to produce pathophysiologic consequences after brain injury. However, the underlying mechanisms that lead to more severe impairment and disruption of neurophysiologic processes are not well understood. Here, we evaluated the effect of constant light exposure on the neurobehavioral impairment and survival of neurons in rats after traumatic brain injury (TBI). Sixty adult male Sprague-Dawley rats were subjected to a weight-drop model of TBI and then exposed to either a standard 12-/12-h light/dark cycle or a constant 24-h light/light cycle for 14 days. Our results showed that 14 days of constant light exposure after TBI significantly worsened the sensorimotor and cognitive deficits, which were associated with decreased body weight, impaired water and food intake, increased cortical lesion volume, and decreased neuronal survival. Furthermore, environmental circadian disruption inhibited cell proliferation and newborn cell survival and decreased immature cell production in rats subjected to the TBI model. We conclude that circadian disruption induced by constant light exposure worsens histologic and neurobehavioral impairment and inhibits neurogenesis in adult TBI rats. Our novel findings suggest that light exposure should be decreased and circadian rhythm reestablished in hospitalized TBI patients and that drugs and strategies that maintain circadian rhythm would offer a novel therapeutic option. [ABSTRACT FROM AUTHOR]

The original version of this article unfortunately contained an error in Fig. 4a. [ABSTRACT FROM AUTHOR]

Selenium (Se) might be protective against oxidative stress at nutritional levels, but elevated Se concentrations in the diet has been revealed as the main culprit for the extinction of natural fish populations in Se-contaminated lakes. Though Se predominate as waterborne selenite (IV) and selenate (VI) in the water, the differences in bioaccumulation, effects (e.g., oxidative stress, antioxidants etc.) and molecular mechanisms between Se(IV) and Se(VI) have been relatively understudied in wild fish. In this study, the P. parva were exposed to waterborne Se (10, 200 and 1000 μg/L of Se(IV) or Se(VI)) and sampled at 4, 14 and 28 days. Bioaccumulation, tissue distributions of Se and following effects in different tissues were evaluated. The results showed that the levels of Se in the gills and intestine were significantly elevated with a seemingly concentration-dependent pattern in the Se(IV) treatment, with respectively 173.3% and 57.2% increase after 28 days of exposure, relative to that of Se(VI) treatment. Additionally, significant accumulation of Se was also observed in the muscle of Se(IV) treated fish. Se exposure increased the MDA levels in the brain and gills in the Se(IV) treatment, but less apparent in the Se(VI) treatment. Meanwhile, Se exposure lowered (at least 56%) the activity of GST in the gills, but increased the activity of AChE in the muscle (~69%) and brain (~50%) after 28 d. Most importantly, after 28 d of exposure, Se exposure caused significant decrease in GSH levels in the gills (at least 35%) and in all tissues examined at the highest test concentration. In general, the results showed that Se(IV) led to faster accumulation of Se than Se(VI) in P. parva, and the resulted lipid peroxidation was closely related to the levels of antioxidants, especially GSH. Our results suggest that the ecotoxicological effects of waterborne selenite and selenate differ in this freshwater species in the field. [ABSTRACT FROM AUTHOR]

Purpose: To report a rare type of Pallister-Killian syndrome (PKS) diagnosed prenatally by the utility of non-invasive prenatal testing (NIPT). Methods: NIPT was performed in the first trimester. Conventional karyotyping and chromosomal microarray analysis (CMA) were performed on the amniotic samples in the second trimester. Copy number variation sequencing (CNV-seq) was used for the validation of fetal skin and the placental tissue after pregnancy termination. Results: NIPT results showed increased signal from chromosome 12p. Subsequent prenatal diagnostic testing by karyotype revealed 47, XY, +i (12p), and CMA displayed four copies of 12p: 12p13.33-12p11.1(173786_34835641) × 4. The CNV-seq results of the fetal skin and the fetal side of placenta showed four copies of 12p13.33-p11 and an estimated chimeric duplication of 34.08 Mb (chimerism ratio: 10%) in 12 p13.33-p11, respectively. However, no abnormality was detected by CNV-seq at the maternal side of placenta. Conclusions: Our findings suggest that a positive signal from chromosome 12p on NIPT should raise suspicion for PKS. With the wide application of NIPT, the true positive of incidental finding is expected to increase. [ABSTRACT FROM AUTHOR]

Stem cell transplantation is a promising therapy for wound healing, but the low retention and survival of transplanted stem cells limit their application. Injectable hydrogels exert beneficial effects in skin tissue engineering. In this study, an injectable hydrogel composed of sodium alginate (SA) and collagen type I (Col) was synthesized as a tissue scaffold to improve the efficacy of stem cells in a full-thickness excision wound model. Our results showed that SA/Col hydrogel was injectable, biodegradable, and exhibited low immunogenicity, which could promote the retention and survival of hUC-MSCs in vivo. SA/Col loaded with hUC-MSCs showed reduced wound size (p < 0.05). Histological and immunofluorescence results confirmed that SA/Col loaded with hUC-MSCs significantly promoted the formation of granulation, enhanced collagen deposition and angiogenesis, increased VEGF and TGF-β1 expression (p < 0.05), and mitigated inflammation evidenced by lower production of TNF-α and IL-1β and higher release of IL-4 and IL-10 (p < 0.05). Furthermore, SA/Col loaded with hUC-MSCs significantly lowered the expression of NLRP3 inflammasome-related proteins (p < 0.05). Taken together, our results suggest that SA/Col loaded with hUC-MSCs promotes skin wound healing via partly inhibiting NLRP3 pathway, which has potential to the treatment of skin wounds. [ABSTRACT FROM AUTHOR]

Objectives: Kidney renal clear cell carcinoma (KIRC) is one of the most common lethal cancers in the human urogenital system. As members of the Homeobox (HOX) family, Homeobox-A (HOXA) cluster genes have been reported to be involved in the development of many cancer types. However, the expression and clinical significance of HOXA genes in KIRC remain largely unknown. Materials and methods: In this study, we comprehensively analyzed the mRNA expression and prognostic values of HOXA genes in KIRC using The Cancer Genome Atlas (TCGA) analysis databases online. Colony formation assay, flow cytometry and Western blot were used to detect cell proliferation, apoptosis, cell cycle, and protein level of the indicated gene. Results: We found that the HOXA genes were differentially expressed in KIRC tissues when compared with normal tissues. The expression of HOXA4 and HOXA13 were significantly up-regulated, while HOXA7 and HOXA11 were down-regulated in KIRC. High mRNA levels of HOXA2, HOXA3 and HOXA13, and low level of HOXA7 predicted poor overall survival (OS) of KIRC patients. High mRNA level of HOXA13 further indicated a poor disease-free survival (DFS) of KIRC patients. Functionally, knockdown of HOXA13 significantly suppressed cell proliferation of KIRC in vitro, increased the protein level of p53 and decreased the protein level of cyclin D1 in KIRC cells. Over-expression of HOXA13 had the opposite effects on KIRC cells. Conclusion: Collectively, our findings suggest that HOXA13 functions as a novel oncogene in KIRC and may be a potential biomarker for this malignancy. [ABSTRACT FROM AUTHOR]

Temozolomide is a first line anti-tumor drug used for the treatment of patients with Glioblastoma multiforme (GBM). However, the drug resistance to temozolomide limits its clinical application. Therefore, novel strategies to overcome chemoresistance are desperately needed for improved treatment of human GBM. Recent studies have demonstrated that miRNAs are closely related to resistance to cancer chemotherapy. This study aimed to further validate the biological role of miR-128-3p and to investigate whether miR-128-3p can enhance the chemosensitivity of glioblastoma to temozolomide (TMZ) and the underlying mechanisms. The effects of miR-128-3p and TMZ on the proliferation of glioblastoma cells were investigated by cell counting kit-8 (cck8). Transwell and intracerebral invasion assays were applied to determine the effects of the combination of miR-128-3p and TMZ on the invasion and migration of glioblastoma in vitro and in vivo. Flow cytometry was used to detect apoptosis in each group, and immunofluorescence was used to determine the expression levels of EMT-related proteins. RT-PCR and Western-blot were applied to detect EMT-transformed proteins (c-Met, PDGFRα, Notch1, and Slug) and EMT phenotype-associated proteins (Vim, CD44, and E-cadherin) at both mRNA and protein levels. Based on the microRNA.org database, we predicted the target genes of miR-128-3p. The target-relationship between miR-128-3p and c-Met and PDGFRα was verified by dual luciferase reporter gene. The tumor volume, weight and the expression levels of the proteins described above were measured in subcutaneously transplanted tumor model in nude mice. We found that the expression of miR-128-3p was down-regulated in glioblastoma tissue samples and cell lines. miR-128-3p suppressed the proliferation, migration, and invasion of GBM both in vitro and in vivo; miR-128-3p enhanced the therapeutic effect of TMZ via inhibition of proliferation, invasion and migration of glioblastoma cells and induction of apoptosis. Overexpression of miR-128-3p down-regulated the expression levels of EMT-transformed proteins (c-Met, PDGFRα, Notch1 and Slug) to enhance the effect of TMZ. In addition, we found that miR-128-3p targeted and bound c-Met. More importantly, the upregulation of c‐Met significantly prompted U87 and U251 cell proliferation. This effect could be abolished when c‐Met was silenced. The investigation in tumor bearing nude mice showed that miR-128-3p in combination with TMZ reduced tumor volume and the invasion extent, and increased the sensitivity of glioblastoma to TMZ. miR-128-3p is capable of enhancing the sensitivity of glioblastoma to TMZ through regulating c-Met/EMT. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) are unique precursor cells characterized by active self-renewal and differentiation potential. These cells offer the advantages of ease of isolation and limited ethical issues as a resource and represent a promising cell therapy for neurodegenerative diseases. However, replicative senescence during cell culture as well as low efficiency of cell migration and differentiation after transplantation are major obstacles. In our previous study, we found that FOXQ1 binds directly to the SIRT1 promoter to regulate cellular senescence and also promotes cell proliferation and migration in many tumor cell lines. Currently, little is known about the effects of FOXQ1 on normal somatic cells. Therefore, we examine the effects of FOXQ1 on senescence and migration of MSCs. Lentiviral vector-mediated overexpression of FOXQ1 in human umbilical cord mesenchymal stem cells (hUC-MSCs) resulted in enhanced cell proliferation and viability. Furthermore, the expression of proteins and markers positively associated with senescence (p16, p21, p53) was reduced, whereas expression of proteins negatively associated with senescence (SIRT1, PCNA) was promoted. Following transplantation of hUC-MSCs overexpressing FOXQ1 in an animal model of Alzheimer’s disease (APPV717I transgenic mice) resulted in amelioration of the effects of Alzheimer’s disease (AD) on cognitive function and pathological senescence accompanied the increased numbers of hUC-MSCs in the AD brain. In conclusion, FOXQ1 overexpression promotes anti-senescence and migration of hUC-MSCs in vitro and in vivo. These findings also suggest that this strategy may contribute to optimization of the efficiency of stem cell therapy. [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI), which can lead to disability, dysfunction, and even death, is a prominent health problem worldwide. Effective therapy for this serious and debilitating condition is needed. Human umbilical cord matrix, known as Wharton's jelly (WJ), provides a natural, interface scaffold that is enriched in mesenchymal stem cells. In this study, we tested the efficacy of WJ tissue transplantation in a weight-drop model of TBI in rats. WJ tissue was cultured and transplanted into the injury site 24 h after TBI. The modified neurologic severity score, body weight, brain edema, and lesion volume were evaluated at various time points after TBI. Cognitive behavior was assessed by the novel object recognition test and the Morris water maze test. Expression of brain-derived neurotrophic factor (BDNF) in the perilesional brain area was measured at day 14 after TBI. We found that WJ tissue transplantation lessened TBI-induced brain edema (day 3), reduced lesion volume (day 28), improved neurologic function (days 21-28), and promoted memory and cognitive recovery. Additionally, expression of BDNF mRNA and protein was higher in WJ tissue-treated rats than in sham-operated or vehicle-treated rats. These data suggest that WJ tissue transplantation can reduce TBI-induced brain injury and may have therapeutic potential for the treatment of TBI. [ABSTRACT FROM AUTHOR]