Bleached bamboo pulp, as a kind of natural cellulose, has received significant attention in the field of biomass materials due to its advantages of environmental protection and the abundance of raw ...materials. Low-temperature alkali/urea aqueous system is a green dissolution technology for cellulose, which has promising application prospects in the field of regenerated cellulose materials. However, bleached bamboo pulp, with high viscosity average molecular weight (
η) and high crystallinity, is difficult to dissolve in an alkaline urea solvent system, restraining its practical application in the textile field. Herein, based on commercial bleached bamboo pulp with high
η, a series of dissolvable bamboo pulps with suitable
η was prepared using a method of adjusting the ratio of sodium hydroxide and hydrogen peroxide in the pulping process. Due to the hydroxyl radicals being able to react with hydroxyls of cellulose, molecular chains are cut down. Moreover, several regenerated cellulose hydrogels and films were fabricated in an ethanol coagulation bath or a citric acid coagulation bath, and the relationship between the properties of the regenerated materials and the
η of the bamboo cellulose was systematically studied. The results showed that hydrogel/film had good mechanical properties, as the
η is 8.3 × 10
and the tensile strength of a regenerated film and the film have values up to 101 MPa and 3.19 MPa, respectively. In this contribution, a simple method of a one-step oxidation of hydroxyl radicals to prepare bamboo cellulose with diversified
η is presented, providing an avenue for a preparation of dissolving pulp with different
η in an alkali/urea dissolution system and expanding the practical applications of bamboo pulp in biomass-based materials, textiles, and biomedical materials.
Water is an indispensable strategic resource for biological and social development. The problem of oily wastewater pollution originating from oil spillages, industrial discharge and domestic oil ...pollution has become an extremely serious international challenge. At present, numerous superwetting materials have been applied to effectively separate oil and water. However, most of these materials are difficult to scale and their large-scale application is limited by cost and environmental protection. Herein, a simple, environmentally friendly strategy including sol-gel, freeze-drying and surface hydrophobic modification is presented to fabricate a bamboo cellulose foam with special wetting characteristics. The bamboo cellulose foam is superhydrophobic, with a water contact angle of 160°, and it has the superoleophilic property of instantaneous oil absorption. Owing to the synergistic effect of the three-dimensional network structure of the superhydrophobic bamboo cellulose foam and its hydrophobic composition, it has an excellent oil-absorption performance of 11.5 g/g~37.5 g/g for various types of oil, as well as good recyclability, with an oil (1,2-dichloroethane) absorption capacity of up to 31.5 g/g after 10 cycles. In addition, the prepared cellulose-based foam exhibits an outstanding performance in terms of acid and alkali corrosion resistance. Importantly, owing to bamboo cellulose being a biodegradable, low-cost, natural polymer material that can be easily modified, superhydrophobic/superoleophilic bamboo cellulose foam has great application potential in the field of oily wastewater treatment.
PURPOSETo compare the effect of different polishing methods and time treatment on the fitness of CAD/CAM zirconia ceramic crowns. METHODSSixteen intact maxillary premolars were randomly divided into ...two groups, group A was treated with silicon carbide burs, while group B was treated with tungsten steel burs. At different polishing time points of the same tooth, digital impressions of each group were obtained, which were used to manufacture CAD/CAM zirconium ceramic crowns. After trial fitting, the gap impressions were obtained by using silicone rubber replication method, and the marginal and internal discrepancies were assessed. The data were statistically analyzed with SPSS 21.0 software package. RESULTSThe difference between the gap values of the marginal and internal markers of group A and group B was not statistically significant(P＞0.05). Compared with the no-polishing process, the differences of the marginal gap (39.67±8.35) μm and internal gap (45.18±7.16) μm of group A polished for 4 min, and the margi
Electroencephalogram(EEG) analysis has important reference value in the diagnosis of epilepsy. The automatic classification of epileptic EEG can be used to judge the patient's situation in time,which ...is of great significance in clinical application. In order to solve the problem that the recognition accuracy is not high by using the single feature of EEG signals and avoid the influence of wavelet basis function selection on recognition results,a method of automatic discrimination of epileptic EEG signals based on S transform and permutation entropy is proposed. Firstly, the original signals are decomposed by discrete S transform, and then we calculate the fluctuation index of coefficients of each rhythm and combine the permutation entropy of EEG signals into a feature vector and use Real AdaBoost classifier to discriminate the epileptic EEG signals in muti-period. In this study, we used the epilepsy database from University of Bonn. Three groups of EEG signals, including the data of normal people with their e
During the last decade, the problem of suicide has become more serious in individuals with depression. Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for major ...depressive disorder (MDD). This study aims to investigate the efficacy of magnetic resonance imaging (MRI)‐based neuronavigation‐guided daily high‐dose rTMS for rapidly improving suicidal ideation in treatment‐naive patients with MDD. In the present 1‐week double‐blind study, 42 treatment‐naive patients with MDD with suicidal ideation were randomly assigned to the treatment of escitalopram oxalate tablets (10 mg/d) in combination with either active (n = 21) or sham (n = 21) rTMS. The TMS coil was positioned over a specified target location (−44, 40, and 29) in left dorsolateral prefrontal cortex based on MRI data. The severity of suicidal ideation was measured by the Beck Scale for Suicide Ideation (BSI). The 24‐item Hamilton Depression Rating Scale (HAMD‐24) and Montgomery–Åsberg Depression Rating Scale (MADRS) were utilized to assess the severity of depression. The Wisconsin Card Sorting Test, Continuous Performance Test, and Stroop Color–Word Test were adopted to assess executive function. In contrast to the sham group, the active rTMS group showed a significantly greater BSI score reduction at the third day and the seventh day (P < 0.001). Moreover, the active rTMS group showed a significantly greater HAMD (P < 0.001) and MADRS (P < 0.001) score reduction at the seventh day in comparison to the sham group. The present findings suggested that the neuronavigation‐guided high‐dose rTMS may be a novel method to rapidly reduce suicidal ideation and mitigate depressive symptoms.
Poor bleaching is a significant problem for Optically Stimulated Luminescence（OSL） dating of glacial sediments. Five young glacial samples（including two modern analogues） from different depositional ...settings were collected beyond the Yingpu Glacier in the eastern Qinghai-Tibetan Plateau. De was determined using different OSL methods. The luminescence characteristics and dating results showed that the large aliquot quartz Blue Stimulated Luminescence（BSL） is more applicable than polymineral infrared stimulated luminescence（IRSL） method. Small aliquot quartz BSL results showed poor luminescence properties due to low luminescence sensitivity of quartz in this area. The dating results also indicated that glaciofluvial samples deposited close to ice margin（~40 m and ~700 m） and supraglacial debris dominated lateral moraine samples are relatively well-bleached, whereas samples from ground moraine and low terminal moraine were poorly bleached, probably due to containing subglacial and englacial debris. The residual doses of glaciofluvial and lateral moraine crest samples were below a few Gy and age overestimations were below a few hundred years. The ground moraine and low terminal moraine samples had residual doses as high as ~110 Gy, and ages were overestimated by ~15-17 ka.
Functional magnetic resonance imaging has been widely used to investigate the effects of acupuncture on neural activity. However, most functional magnetic resonance imaging studies have focused on ...acute changes in brain activation induced by acupuncture. Thus, the time course of the therapeutic effects of acupuncture remains unclear. In this study, 32 patients with amnestic mild cognitive impairment were randomly divided into two groups, where they received either Tiaoshen Yizhi acupuncture or sham acupoint acupuncture. The needles were either twirled at Tiaoshen Yizhi acupoints, including Sishencong（EX-HN1）, Yintang（EX-HN3）, Neiguan（PC6）, Taixi（KI3）, Fenglong（ST40）, and Taichong（LR3）, or at related sham acupoints at a depth of approximately 15 mm, an angle of ± 60°, and a rate of approximately 120 times per minute. Acupuncture was conducted for 4 consecutive weeks, five times per week, on weekdays. Resting-state functional magnetic resonance imaging indicated that connections between cognition-related regions such as the insula, dorsolateral prefrontal cortex, hippocampus, thalamus, inferior parietal lobule, and anterior cingulate cortex increased after acupuncture at Tiaoshen Yizhi acupoints. The insula, dorsolateral prefrontal cortex, and hippocampus acted as central brain hubs. Patients in the Tiaoshen Yizhi group exhibited improved cognitive performance after acupuncture. In the sham acupoint acupuncture group, connections between brain regions were dispersed, and we found no differences in cognitive function following the treatment. These results indicate that acupuncture at Tiaoshen Yizhi acupoints can regulate brain networks by increasing connectivity between cognition-related regions, thereby improving cognitive function in patients with mild cognitive impairment.
The existence of breast cancer stem cells (BCSCs) is a major reason underlying cancer metastasis and recurrence after chemotherapy and radiotherapy. Targeting BCSCs may ameliorate breast cancer ...relapse and therapy resistance. Here we report that expression of the pseudokinase Tribble 3 (TRIB3) positively associates with breast cancer stemness and progression. Elevated TRIB3 expression supports BCSCs by interacting with AKT to interfere with the FOXO1-AKT interaction and suppress FOXO1 phosphorylation, ubiquitination, and degradation by E3 ligases SKP2 and NEDD4L. The accumulated FOXO1 promotes transcriptional expression of SOX2, a transcriptional factor for cancer stemness, which in turn, activates FOXO1 transcription and forms a positive regulatory loop. Disturbing the TRIB3-AKT interaction suppresses BCSCs by accelerating FOXO1 degradation and reducing SOX2 expression in mouse models of breast cancer. Our study provides insights into breast cancer development and confers a potential therapeutic strategy against TRIB3-overexpressed breast cancer.
Climate change and pesticide resistance are two of the most imminent challenges human society is facing today. Knowledge of how the evolution of pesticide resistance may be affected by climate change ...such as increasing air temperature on the planet is important for agricultural production and ecological sustainability in the future but is lack in scientific literatures reported from empirical research. Here, we used the azoxystrobin‐Phytophthora infestans interaction in agricultural systems to investigate the contributions of environmental temperature to the evolution of pesticide resistance and infer the impacts of global warming on pesticide efficacy and future agricultural production and ecological sustainability. We achieved this by comparing azoxystrobin sensitivity of 180 P. infestans isolates sampled from nine geographic locations in China under five temperature schemes ranging from 13 to 25°C. We found that local air temperature contributed greatly to the difference of azoxystrobin tolerance among geographic populations of the pathogen. Both among‐population and within‐population variations in azoxystrobin tolerance increased as experimental temperatures increased. We also found that isolates with higher azoxystrobin tolerance adapted to a broader thermal niche. These results suggest that global warming may enhance the risk of developing pesticide resistance in plant pathogens and highlight the increased challenges of administering pesticides for effective management of plant diseases to support agricultural production and ecological sustainability under future thermal conditions.
Expected global changes in environmental conditions underline the need for a better understanding of genetic variation in ecological traits and their strategies of adaptation to the stresses. In this ...study, evolutionary mechanisms and processes of UV adaptation in plant pathogens were investigated by combining statistical genetics, physiological assays, and common garden experiment approaches in an assessment of the potato late blight pathogen, Phytophthora infestans, sampled from various geographic locations in China. We found spatial divergence caused by diversifying selection in UV tolerance among P. infestans populations. Local UV radiation was the driving force of selection as indicated by a positive correlation between UV tolerance in P. infestans populations and the altitude of collection sites. Plasticity accounted for 68% of population variation while heritability was negligible, suggesting temporary changes in gene expression and/or enzymatic activity play a more important role than permanent modification of gene structure in the evolution of UV adaptation. This adaptation strategy may explain the lack of fitness penalty observed in genotypes with higher UV tolerance.
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