Association between screen time and depressive symptoms in a sample of Chinese medical students: Mediator role of empathy.

Medical students are at high risk of psychological subhealth under heavy stress with increasing screen time. This study aimed to explore the association between screen time and depressive symptoms and determine empathy as a mediating factor. In this cross-sectional study, a total of 945 medical students were surveyed, and 924 medical students were ultimately included after standard exclusion criteria. They reported their daily screen time and completed the Chinese version of the Jefferson Scale of Empathy-Student Version (JSE-S) and the Self-Rating Depression Scale (SDS). t tests and analysis of variance showed a significant difference in empathy and depressive symptoms by sex, stage, and screen time. The correlation analysis revealed that both affective and cognitive empathy have inverse associations with depressive symptoms. The mediation model confirmed that cognitive empathy played a positive mediating role between screen time and depressive symptoms, reducing the impact of screen time on depressive symptoms. Our study may add empirical evidence to prevent and intervene in depressive symptoms. These findings call for considering controlling screen time and enhancing cognitive empathy as interventions for medical students' depressive symptoms.

Employing deep eutectic solvent synthesized by cetyltrimethylammonium bromide and ethylene glycol to advance enzymatic hydrolysis efficiency of rape straw.

An efficient deep eutectic solvent (DES) was synthesized by cetyltrimethylammonium bromide (CTAB) and ethylene glycol (EG) and employed to treat rape straw (RS) for advancing enzymatic saccharification in this work. By optimizing the pretreatment parameters, the results displayed that the novel DES was strongly selective towards removing lignin and xylan while preserving cellulose. Under optimum conditions with 1:6 of CTAB: EG in DES, 180 °C and 80 min, the enzymatic hydrolysis efficiency of RS was enhanced by 46.0% due to the 62.2% of delignification and 53.2% of xylan removal during CTAB: EG pretreatment. In terms of the recalcitrant structure of RS, DES pretreatment caused the increment of cellulosic accessibility, reduction of hydrophobicity and surface area of lignin, and migration of cellulosic crystalline structure, which was associated with its enzymatic hydrolysis efficiency. Overall, this study presented an emerging method for the effective fractionation and valorization of lignocellulosic biomass within biorefinery technology.

Transcription Factor Spo0A Regulates the Biosynthesis of Difficidin in Bacillus amyloliquefaciens.

Bacillus amyloliquefaciens WH1 produces multiple antibiotics with antimicrobial activity and can control bacterial wilt disease caused by Ralstonia solanacearum. Antibacterial substances produced by WH1 and the regulation mechanism are unknown. In this study, it was found that difficidin, and to a minor extent bacillibactin, exhibited antibacterial activity against R. solanacearum. Lipopeptides, macrolactin, bacillaene, and bacilysin had no antibacterial activity. Ferric iron uptake transcriptional regulator Fur bound the promoter region of the dhb gene cluster of bacillibactin biosynthesis. Mutant Δfur showed a higher bacillibactin production and its antibacterial activity increased by 27% than wild-type WH1. Difficidin inhibited R. solanacearum growth and disrupted the integrity of the cells. Lack of transcription factor Spo0A abolished difficidin biosynthesis. Spo0A bound the promoter region of the dfn gene cluster of difficidin biosynthesis. Changing phosphorylation levels of Spo0A via deletion of phosphatase gene spo0E and histidine kinases genes kinA and kinD affected the biosynthesis of difficidin. Deletion of spo0E increased the phosphorylation level of Spo0A and consequently improved the difficidin production. The antibacterial activity of mutant Δspo0E and ΔkinA increased by 12% and 19%. The antibacterial activity of mutant ΔkinD decreased by 28%. Collectively, WH1 produced difficidin to disrupt the cell of R. solanacearum and secreted siderophore bacillibactin to compete for ferric iron. Spo0A regulated difficidin biosynthesis. Spo0A regulates quorum-sensing responses and controls the biosynthesis of secondary metabolites in B. amyloliquefaciens. This study has important findings in the regulation mechanism of antibiotic synthesis and helps to improve antibiotic yield in Bacillus. IMPORTANCE Pathogen R. solanacearum causes bacterial wilt disease in many crops. There is no chemical bactericide that can control bacterial wilt disease. It is vital to find antagonistic microorganisms and antibacterial substances that can efficiently control bacterial wilt disease. B. amyloliquefaciens WH1 could inhibit the growth of R. solanacearum. Via genetic mutation, it was found that difficidin and to a minor extent bacillibactin produced by WH1 acted efficiently against R. solanacearum. The transcription factor Spo0A regulated the synthesis of difficidin. Phosphorylation of Spo0A affected the production of difficidin. Increasing the phosphorylation level of Spo0A improved the difficidin production and antibacterial activity. In-depth analysis of the regulation mechanism of antibiotic difficidin is meaningful for enhancing the control efficiency of WH1. B. amyloliquefaciens WH1 and the antibacterial substances have vast application potential in controlling bacterial wilt disease.

Combined sulfuric acid and choline chloride/glycerol pretreatment for efficiently enhancing enzymatic saccharification of reed stalk.

In this study, an efficient combination of pretreatment solvents involving Choline chloride/Glycerol (ChCl/Gly) and H2SO4 was firstly developed to assess the pretreatment performance and determine optimal pretreatment conditions. The results illustrated that the H2SO4-[ChCl/Gly] combination efficiently removed lignin (52.6%) and xylan (80.5%) from the pretreated reed stalk, and subsequent enzymatic hydrolysis yielded 91.1% of glucose. Furthermore, several characterizations were conducted to examine the structural and morphological changes of the reed stalk, revealing apparently enhanced accessibility (128.4 to 522.6 mg/g), reduced lignin surface area (357.9 to 229.5 m2/g), and substantial changes on biomass surface. Based on the aforementioned study, possible mechanisms for the H2SO4-[ChCl/Gly] pretreatment of reed stalks were proposed. The comprehensive understanding of combined H2SO4-[ChCl/Gly] pretreatment system for enhancing the saccharification of the reed stalk was interpreted in this work. Overall, this novel approach could be efficiently applied to pretreat and saccharify reed stalks, empowering the biomass refining industry.

Enhancing enzymatic saccharification of sunflower straw through optimal tartaric acid hydrothermal pretreatment.

Sunflower straw, a usually neglected and abundant agricultural waste, has great potential for contributing to environmental protection realizing its high-value of valorization if utilizing properly. Because hemicellulose contains amorphous polysaccharide chains, relatively mild organic acid pretreatment can effectively reduce its resistance. Through hydrothermal pretreatment, sunflower straw was pretreated in tartaric acid (1 wt%) at 180 °C for 60 min to enhance its reducing sugar recovery. After tartaric acid-assisted hydrothermal pretreatment, 39.9% of lignin and 90.2% of xylan were eliminated. The reducing sugar recovery increased threefold, while the solution could be effectively reused for four cycles. The properties of more porous surface, improved accessibility, and decreased surface lignin area of sunflower straw were observed through various characterizations, which explained the improved saccharide recovery and provided a basis for the mechanism of tartaric acid-assisted hydrothermal pretreatment. Overall, this tartaric acid hydrothermal pretreatment strategy greatly provided new impetus for the biomass refinery.

Significantly enhanced enzymatic hydrolysis of waste rice hull through a novel surfactant-based deep eutectic solvent pretreatment.

The potential of green solvents, specifically deep eutectic solvents (DESs), has piqued the interest of researchers in the field of lignocellulose pretreatment. To enhance the enzymatic digestion efficiency of waste rice hull (RCH), an effective pretreatment approach was developed using the DES [AA][CATB], which was made with acetic acid (AA) and cetyltrimethylammonium bromide (CTAB). The results showed that [AA][CATB] improved enzymatic saccharification by 3.7 times compared to raw RCH and efficiently eliminated lignin and removed xylan. The improvement in enzymatic hydrolysis efficiency was then interpreted by a series of characterizations that showed a great morphological changed RCH with an obvious accessibility increase and a lignin surface area and hydrophobicity reduction. This work demonstrates that functional, and easily recoverable DESs have potential for improving the efficiency of lignocellulose pretreatment in biorefineries, providing a promising approach for developing green solvents and achieving more sustainable and efficient biorefinery processes.

Implementing dilute acid pretreatment coupled with solid acid catalysis and enzymatic hydrolysis to improve bioconversion of bamboo shoot shells.

Exploiting bamboo shoot shells (BSS) as feedstocks for biorefining is a crucial scheme to advance the bioavailability of bamboo shoots. This work applied traditional dilute sulfuric acid pretreatment (DAP) to treat BSS and simultaneously prepared the solid-acid-catalyst by using BSS as carbon-based carriers. The biocatalysis of the prehydrolysate from DAP and enzymatic hydrolysis of pretreated BSS was subsequently performed to achieve efficient bioconversion of its carbohydrates. The results displayed that 0.1 g/L H2SO4 employed in DAP was the optimal condition for furfural conversion of BSS during biocatalysis, reaching the maximum of 41%. Meanwhile, the enzymatic hydrolysis efficiency of the pretreated BSS also reached the maximum of 97%. This increment of efficiency was ascribed to the enhancement of accessibility and cellulosic crystal size, and also the reduction of surface area of lignin in BSS. Ultimately, the efficient bioutilization of BSS and bioconversion of its carbohydrates were realized by DAP technology.

A novel cetyltrimethylammonium bromide-based deep eutectic solvent pretreatment of rice husk to efficiently enhance its enzymatic hydrolysis.

Deep eutectic solvent (DES) has caught widely attention of researchers in biomass pretreatment. As a highly efficient surfactant, cetyltrimethylammonium bromide (CTAB) was expected to be used for synthesizing new DESs with additional functions in pretreatment. In this work, an efficient pretreatment method using a mixture of CTAB and lactic acid (LA) as a novel functional DES was established to improve enzymatic digestion efficiency of rice husk (RH). The results showed that DES CTAB:LA effectively removed lignin (51.5%) and xylan (79.9%) and the enzymatic hydrolysis activity of CTAB:LA-treated RH was 5 times that of RH. Then, a series of characterization demonstrated that a substantial accessibility increased, a hydrophobicity and lignin surface area decreased, and great surface morphology alternation were observed on the treated RH, which explained the increase in enzymatic hydrolysis efficiency. Overall, the discovery of more functional DESs might be motivated and biorefinery pretreatment processes might be greatly promoted.

An efficient chemoenzymatic cascade strategy for transforming biomass into furfurylamine with lobster shell-based chemocatalyst and mutated ω-transaminase biocatalyst in methyl isobutyl ketone-water.

To date, an efficient process for manufacturing valuable furan compounds from available renewable resources has gained great attention via a chemoenzymatic route. In this study, a sulfonated tin-loaded heterogeneous catalyst CLUST-Sn-LS using lobster shell as biobased carrier was prepared to convert corncob (75.0 g/L) into furfural (122.5 mM) at 170 °C for 30 min in methyl isobutyl ketone (MIBK)-H2O biphasic system (2:1, v/v). To improve furfurylamine yield, a novel recombinant E. coli TFTS harboring robust mutant Aspergillus terreus ω-transaminase [hydrophilic threonine (T) at position 130 was site-directed mutated to hydrophobic phenylalanine (F)] was constructed to transform 300-500 mM furfural into furfurylamine (90.1-93.6 % yield) at 30 °C and pH 7.5 in MIBK-H2O. Corncob was converted to furfurylamine in MIBK-H2O with a high productivity of 0.461 g furfurylamine/(g xylan). This constructed chemoenzymatic method coupling bio-based chemocatalyst CLUST-Sn-LS and mutant ω-transaminase biocatalyst in a biphasic system could efficiently convert lignocellulose into furfurylamine.

Parental care and depressive symptoms among Chinese medical students: roles of empathy and gender.

BACKGROUND: Medical students in China who face the dual pressure of study and employment tend to experience subclinical depressive symptoms. Parental care plays an important direct and indirect role in the psychological development of medical students, and the extent and mechanism of this role urgently need to be studied and discussed. METHODS: After simple random sampling and screening of valid questionnaires, data from a total of 924 people were used. The participants completed the parental bonding instrument, self-rating depression scale, Chinese version of the Jefferson empathy scale-medical student edition and self-rating anxiety scale to evaluate parental care, empathy, depressive symptoms and anxiety. The data were statistically processed using a descriptive analysis, correlation analysis and test of moderated mediation. RESULTS: Maternal care had a significant negative predictive effect on depressive symptoms among medical students. Strong maternal care can reduce the occurrence of depressive symptoms in medical students. Empathy played a positive mediating role such that both types of empathy could alleviate the effect of weak maternal care on the depressive symptoms of medical students. However, neither cognitive empathy nor affective empathy played a mediating role in the relationship between paternal care and depressive symptoms. Nevertheless, the relationship between maternal care and empathy was moderated by the medical students' gender. CONCLUSIONS: The effect of this relationship on female medical students deserves special attention. The results of this study provide a reference and basis for the adjustment of medical education. This study could also help in the design of effective psychological intervention measures to reduce the degree of depressive symptoms and enhance personal empathy.

Improved one-pot synthesis of furfural from corn stalk with heterogeneous catalysis using corn stalk as biobased carrier in deep eutectic solvent-water system.

Using acid-treated corn stalk (CS) as biobased carrier, heterogeous SO42-/SnO2-CS catalyst was firstly prepared to catalyze CS into fufural in deep eutectic solvent-water system. The physical properties of SO42-/SnO2-CS were captured by FT-IR, NH3-TPD, XRD, XPS, and BET. SO42-/SnO2-CS (1.2 wt%) could be used to catalyze CS (75.0 g/L) with MgCl2 (15.0 g/L) to produce furfural (102.3 mM) in the yield of 68.2% for 0.5 h at 170 °C in ChCl:EG-water (20:80, v:v). Moreover, enhanced synthesis of furfural was explored based on the structure changes of CS, furfural yields and formation of byproducts. Finally, the potential catalytic mechanism for catalyzing CS into furfural and byproducts was proposed using SO42-/SnO2-CS as catalyst in ChCl:EG-water containing MgCl2. In summary, this established ChCl:EG-water system and optimized catalytic condition facillitated to synthesize furfural from biomass with biobased solid acid catalyst.

Enhanced conversion of biomass to furfurylamine with high productivity by tandem catalysis with sulfonated perlite and ω-transaminase whole-cell biocatalyst.

Production of bio-based chemicals from renewable bioresource is a key driver for moving towards sustainable industry. Furfurylamine is known as an important furfural-upgrading product in organic synthesis, as well as monolithic synthetic pharmaceuticals, fibers, additives and polymers. In one-pot manner, biomass was tandemly catalyzed to furfurylamine with sulfonated Sn-PL catalyst and recombinant ω-transaminase biocatalyst. Sn-PL (2.4 wt%) catalyzed bamboo shoot shell, corncob and rice straw (75.0 g/L) to 76.5-113.0 mM furfural at 44.7-58.5 % yield in γ-valerolactone-water (2:8, v:v) at 170 ℃. The obtained biomass slurries containing furfural were biotransformed to furfurylamine at high yield (0.39-0.42 g furfurylamine/g xylan in biomass) with ω-transaminase biocatalyst using isopropylamine (3.0 mol isopropylamine/mol furfural) as amine donor at 35 ℃. Such a chemoenzymatic one-pot process combined the advantages of both solid acids and whole-cells catalysts, which provided an efficient and sustainable approach for preparing an important bio-based furan chemical furfurylamine.

[Mechanisms and applications of transcutaneous electrical nerve stimulation in analgesia].

Transcutaneous electrical nerve stimulation (TENS), as a non-pharmacological and non-invasive analgesic therapy with low-cost, has been widely used to relieve pain in various clinical applications, by delivering current pulses to the skin area to activate the peripheral nerve fibers. Nevertheless, analgesia induced by TENS varied in the clinical practice, which could be caused by the fact that TENS with different stimulus parameters has different biological mechanisms in relieving pain. Therefore, to advance our understanding of TENS in various basic and clinical studies, we discussed (1) neurophysiological and biochemical mechanisms of TENS-induced analgesia; (2) relevant factors that may influence analgesic effects of TENS from the perspectives of stimulus parameters, including stimulated position, pulse parameters (current intensity, frequency, and pulse width), stimulus duration and used times in each day; and (3) applications of TENS in relieving clinical pain, including post-operative pain, chronic low back pain and labor pain. Finally, we propose that TENS may involve multiple and complex psychological neurophysiological mechanisms, and suggest that different analgesic effects of TENS with different stimulus parameters should be taken into consideration in clinical applications. In addition, to optimize analgesic effect, we recommend that individual-based TENS stimulation parameters should be designed by considering individual differences among patients, e.g., adaptively adjusting the stimulation parameters based on the dynamic ratings of patients' pain.

Analgesia induced by self-initiated electrotactile sensation is mediated by top-down modulations.

It is well known that sensory perception can be attenuated when sensory stimuli are controlled by self-initiated actions. This phenomenon is explained by the consistency between forward models of anticipated action effects and actual sensory feedback. Specifically, the brain state related to the binding between motor processing and sensory perception would have inhibitory function by gating sensory information via top-down control. Since the brain state could casually influence the perception of subsequent stimuli of different sensory modalities, we hypothesize that pain evoked by nociceptive stimuli following the self-initiated tactile stimulation would be attenuated as compared to that following externally determined tactile stimulation. Here, we compared psychophysical and neurophysiological responses to identical nociceptive-specific laser stimuli in two different conditions: self-initiated tactile sensation condition (STS) and nonself-initiated tactile sensation condition (N-STS). We observed that pain intensity and unpleasantness, as well as laser-evoked brain responses, were significantly reduced in the STS condition compared to the N-STS condition. In addition, magnitudes of alpha and beta oscillations prior to laser onset were significantly larger in the STS condition than in the N-STS condition. These results confirmed that pain perception and pain-related brain responses were attenuated when the tactile stimulation was initiated by subjects' voluntary actions, and exploited neural oscillations reflecting the binding between motor processing and sensory feedback. Thus, our study elaborated the understanding of underlying neural mechanisms related to top-down modulations of the analgesic effect induced by self-initiated tactile sensation, which provided theoretical basis to improve the analgesic effect in various clinical applications.

Activity of factor VII in patients with isolated blunt traumatic brain injury: association with coagulopathy and progressive hemorrhagic injury.

BACKGROUND: Given the importance of factor VII (FVII) in extrinsic pathway of coagulation cascade, we sought to elucidate the relationship between FVII and traumatic brain injury-induced coagulopathy and progressive hemorrhagic injury (PHI). METHODS: Eighty-one patients with isolated traumatic brain injury, 16 years or older, were recruited between 2010 and 2012. Blood was collected on arrival in the emergency department and analyzed with activated partial thromboplastic time, international normalized ratio, platelet count, and activity of FVII. Coagulopathy was defined as thrombocytopenia (platelet count < 120,000/µL) or elevated international normalized ratio of greater than 1.2 or prolonged activated partial thromboplastin time greater than 40 seconds at admission. PHI was present when the follow-up computed tomographic scan reported any increase in size or number of the hemorrhagic lesions. Logistic regression examined the risks for coagulopathy and PHI. RESULTS: Mean (SD) FVII activity in patients with coagulopathy was 85.69% (34.88%), which was significantly lower than patients without coagulopathy (99.57% [29.37%], p = 0.04). Isolated traumatic brain injury patients with FVII activity less than 77.5% have an odds ratio for coagulopathy of 5.52 (95% confidence interval, 1.82-16.68; p = 0.03) relative to patients with FVII activity of 77.5% or greater. Mean (SD) FVII activity in patients with PHI was 70.76% (18.21%), which was significantly lower than patients without PHI (105.76% [32.27%], p < 0.001). A stepwise logistic regression analysis identified FVII less than 77.5% (odds ratio, 4.53; 95% confidence interval, 1.62-12.67; p = 0.004) as a predisposing risk factors independently associated with the presence of PHI. The overall mortality rate in the study population was 7.4% (n = 6). The plasma FVII in death patients (91.44% [47.19%]) was slightly lower than that in survival patients (92.01% [32.04%]). However, there was no statistical difference between the two groups (p = 0.95). CONCLUSION: A decrease of FVII activity significantly contributes to the coagulopathy and PHI in patients with isolated traumatic brain injury. LEVEL OF EVIDENCE: Prognostic study, level III.