MFN1 structures reveal nucleotide-triggered dimerization critical for mitochondrial fusion.

Mitochondria are double-membraned organelles with variable shapes influenced by metabolic conditions, developmental stage, and environmental stimuli. Their dynamic morphology is a result of regulated and balanced fusion and fission processes. Fusion is crucial for the health and physiological functions of mitochondria, including complementation of damaged mitochondrial DNAs and the maintenance of membrane potential. Mitofusins are dynamin-related GTPases that are essential for mitochondrial fusion. They are embedded in the mitochondrial outer membrane and thought to fuse adjacent mitochondria via combined oligomerization and GTP hydrolysis. However, the molecular mechanisms of this process remain unknown. Here we present crystal structures of engineered human MFN1 containing the GTPase domain and a helical domain during different stages of GTP hydrolysis. The helical domain is composed of elements from widely dispersed sequence regions of MFN1 and resembles the 'neck' of the bacterial dynamin-like protein. The structures reveal unique features of its catalytic machinery and explain how GTP binding induces conformational changes to promote GTPase domain dimerization in the transition state. Disruption of GTPase domain dimerization abolishes the fusogenic activity of MFN1. Moreover, a conserved aspartate residue trigger was found to affect mitochondrial elongation in MFN1, probably through a GTP-loading-dependent domain rearrangement. Thus, we propose a mechanistic model for MFN1-mediated mitochondrial tethering, and our results shed light on the molecular basis of mitochondrial fusion and mitofusin-related human neuromuscular disorders.

Predictors of academic career progression among early career physician-scientists via an intensive research training program abroad: a case study.

BACKGROUND: Despite extensive efforts to revitalize the physician-scientist pipeline, attrition has been observed along the physician-scientist developmental pathway. Research exposure during clinical training is considered an important factor favoring the decision to pursue an academic career pathway. METHODS: The authors sought to identify factors associated with academic career progression among junior physician-scientists following the completion of an intensive research training program, using the framework of the Social Cognitive Career Theory (SCCT), to benefit the design of efforts to revitalize the physician-scientist career pipeline. We conducted a retrospective study of 108 physicians who completed a long-term research training program abroad during residency, or within a few years post-residency completion, between 2010 and 2017. With potential predictors of academic career progression prioritized by SCCT, multivariable logistic regression was used to identify predictors of sustained research involvement, high productivity and high research competency after training, respectively. The SCCT was used to illuminate our findings. RESULTS: Co-publications with training supervisors abroad and medical oncology/pediatric oncology as a clinical specialty were positively associated with sustained research involvement and high productivity. Joining the training program after the age of 36 was negatively associated with high research competency. All of the predictors shared a common feature of high correlation with both self-efficacy and environmental elements, the reciprocal interactions of which may affect the career progression of physician-scientists. CONCLUSIONS: Insights gained through this analysis provide policy recommendations for the designing of efforts to revitalize the physician-scientist career pipeline. Priorities should be given to institutional oversight to ensure strengthened self-efficacy at the beginning of one's academic career, by providing long-term research training opportunities to young residents and promoting co-publications with their training supervisors during the training. In order to avoid the negative impact to self-efficacy caused by patient-related burnout or academic isolation, academic medical centers should take measures to guarantee protected research time, and to develop a positive culture encouraging mentoring relationships between junior and experienced physician-scientists in medical departments.

Structures of mammalian GLD-2 proteins reveal molecular basis of their functional diversity in mRNA and microRNA processing.

The stability and processing of cellular RNA transcripts are efficiently controlled via non-templated addition of single or multiple nucleotides, which is catalyzed by various nucleotidyltransferases including poly(A) polymerases (PAPs). Germline development defective 2 (GLD-2) is among the first reported cytoplasmic non-canonical PAPs that promotes the translation of germline-specific mRNAs by extending their short poly(A) tails in metazoan, such as Caenorhabditis elegans and Xenopus. On the other hand, the function of mammalian GLD-2 seems more diverse, which includes monoadenylation of certain microRNAs. To understand the structural basis that underlies the difference between mammalian and non-mammalian GLD-2 proteins, we determine crystal structures of two rodent GLD-2s. Different from C. elegans GLD-2, mammalian GLD-2 is an intrinsically robust PAP with an extensively positively charged surface. Rodent and C. elegans GLD-2s have a topological difference in the ß-sheet region of the central domain. Whereas C. elegans GLD-2 prefers adenosine-rich RNA substrates, mammalian GLD-2 can work on RNA oligos with various sequences. Coincident with its activity on microRNAs, mammalian GLD-2 structurally resembles the mRNA and miRNA processor terminal uridylyltransferase 7 (TUT7). Our study reveals how GLD-2 structurally evolves to a more versatile nucleotidyltransferase, and provides important clues in understanding its biological function in mammals.

FAM46B is a prokaryotic-like cytoplasmic poly(A) polymerase essential in human embryonic stem cells.

Family with sequence similarity (FAM46) proteins are newly identified metazoan-specific poly(A) polymerases (PAPs). Although predicted as Gld-2-like eukaryotic non-canonical PAPs, the detailed architecture of FAM46 proteins is still unclear. Exact biological functions for most of FAM46 proteins also remain largely unknown. Here, we report the first crystal structure of a FAM46 protein, FAM46B. FAM46B is composed of a prominently larger N-terminal catalytic domain as compared to known eukaryotic PAPs, and a C-terminal helical domain. FAM46B resembles prokaryotic PAP/CCA-adding enzymes in overall folding as well as certain inter-domain connections, which distinguishes FAM46B from other eukaryotic non-canonical PAPs. Biochemical analysis reveals that FAM46B is an active PAP, and prefers adenosine-rich substrate RNAs. FAM46B is uniquely and highly expressed in human pre-implantation embryos and pluripotent stem cells, but sharply down-regulated following differentiation. FAM46B is localized to both cell nucleus and cytosol, and is indispensable for the viability of human embryonic stem cells. Knock-out of FAM46B is lethal. Knock-down of FAM46B induces apoptosis and restricts protein synthesis. The identification of the bacterial-like FAM46B, as a pluripotent stem cell-specific PAP involved in the maintenance of translational efficiency, provides important clues for further functional studies of this PAP in the early embryonic development of high eukaryotes.

Comparing of Frequency Shift and Impedance Analysis Method Based on QCM Sensor for Measuring the Blood Viscosity.

Blood viscosity measurements are crucial for the diagnosis of cardiovascular and hematological diseases. Traditional blood viscosity measurements have obvious limitations because of their expensive equipment usage and large sample consumption. In this study, blood viscosity was measured by the oscillating circuit method and impedance analysis method based on single QCM. In addition, the effectiveness of two methods with high precision and less sample is proved by the experiments. Moreover, compared to the result from a standard rotational viscometer, the maximum relative errors of the proposed oscillating circuit method and impedance analysis method are ±5.2% and ±1.8%, respectively. A reliability test is performed by repeated measurement (N = 5), and the result shows that the standard deviation about 0.9% of impedance analysis is smaller than that of oscillating circuit method. Therefore, the impedance analysis method is superior. Further, the repeatability of impedance analysis method was evaluated by regression analysis method, and the correlation coefficient R2 > 0.965 demonstrated that it had excellent reproducibility.

Muscle strength performed better than muscle mass in identifying cognitive impairment risk in maintenance hemodialysis patients.

OBJECTIVES: The association between muscle mass and cognitive impairment (CI) is conflicting. We aimed to evaluate and compare the associations of muscle strength, muscle mass and CI risk in maintenance hemodialysis (MHD) patients. METHODS: We conducted a multicenter, cross-sectional study. Cognitive function was assessed with the Mini-Mental State Examination (MMSE) score. Muscle strength was assessed by hand grip strength (HGS), muscle mass was assessed by lean tissue mass (LTM). Education status was divided into two groups: lower education status (senior middle school and below) and higher education status (high school and above). Multivariable logistic regression models and subgroup analyses were performed. Receiver-operating characteristic (ROC) analyses were conducted to compare their predictive power in discriminating CI. RESULTS: 2827 adult MHD patients were included in our final analysis. Patients in the lowest quartile of HGS was 2.82-fold as likely to have CI as compared to those in the highest quartile, while participants in the lowest quartile of LTM group were 1.52-fold as likely to have CI, when compared with the highest quartile group of LTM after adjusting for age, gender and education level. The association persisted in all subgroups except for women and well-educated participants. There was a significant interaction between HGS and education status on CI and age played an interactive role in the association between LTM and incident CI (P for interaction < 0.05). The AUC value of the HGS was significantly higher than that of LTM (0.69 VS 0.63, P < 0.001). CONCLUSIONS: Muscle strength performed better than muscle mass in identifying individuals at high risk of CI, particularly in male and less educated Chinese MHD patients. LEVEL OF EVIDENCE: Level V, cross-sectional study.

Prognostic factors for the recurrence of afebrile seizures after benign convulsions associated with mild gastroenteritis.

OBJECTIVE: The overall prognosis of benign convulsions associated with mild gastroenteritis (CwG) is favorable, and the incidence of afebrile seizure recurrence with or without gastroenteritis (ASwGI and ASwoGI, respectively) is low. In this study we investigated the prognostic factors associated with afebrile seizure (AS) relapse after the first CwG episode. METHODS: A hospital-based cohort with an initial CwG episode from January 2012 to October 2019 was followed for at least 19 months. The relapse types were divided into ASwGI and ASwoGI. Logistic regression analysis was performed to identify the independent prognostic factors for the recurrence of AS after the initial CwG episode. Furthermore, the clinical characteristics between ASwGI and ASwoGI were compared. RESULTS: Among the 868 patients enrolled, 67 (7.7%) experienced a second AS and 71% (48/67) showed gastroenteritis-associated recurrence. Except for five patients with subsequent epilepsy (0.6%), only eight (0.9%) experienced three seizure episodes. The independent predictive factors for the subsequent recurrence of AS were age less than 18 months at onset (odds ratio [OR]: 2.93, 95% confidence interval [CI]: 1.53-5.63), repeated seizures over 24 h (OR: 4.09, 95% CI: 2.19-7.65), and absence of fever (OR: 2.33, 95% CI: 1.26-4.33) during the first CwG episode. The probability of recurrence of AS for those with one, two, and three predictive factors was 3.23%, 13.35%, and 22.85%, respectively. In addition, the age at onset was significantly lower in the ASwoGI group than in the ASwGI group during the first episode (p < .05). SIGNIFICANCE: The risk of AS relapse after the initial CwG episode is low, and the majority of patients presented with gastroenteritis. The risk can be predicted by age at onset, repeated seizures over 24 h, and absence of fever during the first CwG episode.

Novel graphitic sheets with ripple-like folds as an NCA cathode coating layer for high-energy-density lithium-ion batteries.

In this work, novel graphitic sheets with ripple-like folds (GSRFs) are synthesized from cheap resin via a facile route. The obtained GSRFs are used as a cladding layer for LiNi0.8Co0.15Al0.05O2 (NCA) particles to construct a GSRF@NCA composite cathode. Electrochemical testing for GSFR@NCA exhibits better cycling and C-rate performance than those of original NCA. Moreover, the capacity retention (85%) of the full-cell (GSFR@NCA versus graphite) is much higher than that (79%) of the full-cell (NCA versus graphite) after 400 cycles. Most importantly, this approach allows the preparation of GSFR@NCA with highly promising applications as a cathode for high-energy-density lithium-ion batteries, since in this contribution just simple equipment and a precursor with low cost are involved.

Concomitant activation of the PI3K/Akt and ERK1/2 signalling is involved in cyclic compressive force-induced IL-6 secretion in MLO-Y4 cells.

IL-6 has a dual role in bone remodelling. The ERK1/2 pathway partially upregulated IL-6 secretion in osteocyte-like MLO-Y4 cells exposed to CCF. We have now investigated the possible role of phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway in the CCF-induced IL-6 expression. MLO-Y4 cells were treated with CCF 2,000 µstrain, 2 Hz, or 10, 30 min, 1, 3 and 6 h. IL-6 expression, Akt and ERK1/2 and PI3K/Akt phosphorylation were determined by RT-PCR, ELISA and Western blotting. Inhibition of PI3K/Akt with LY294002 or ERK1/2 with PD98059 significantly attenuated IL-6 upregulation, and IL-6 expression was abolished by inhibiting both pathways. Inhibition of one pathway downregulated the other's phosphorylation level. In conclusion, concomitant activation of PI3K/Akt and ERK1/2 pathways mediated IL-6 expression in MLO-Y4 cells under CCF.

Efficacy and safety of bupivacaine versus lidocaine in dental treatments: a meta-analysis of randomised controlled trials.

The objective of this study was to assess the efficacy and safety of bupivacaine compared with lidocaine in local anaesthesia in dental treatment. Medline, Cochrane Central Register of Controlled Trials, EMBASE, Chinese BioMedical Literature Database, China National Knowledge Infrastructure, and the World Health Organisation (WHO) International Clinical Trials Registry Platform were searched electronically. Relevant journals and references of studies included were hand-searched for randomised controlled trials comparing bupivacaine with lidocaine in terms of efficacy and safety. Sixteen studies were included, of which nine had low, six had moderate and one had high risk of bias. In comparison with 2% lidocaine plus 1:100,000 adrenaline, 0.5% bupivacaine plus 1:200,000 adrenaline showed a higher success rate in inflamed pulp (P = 0.03) but a lower success rate in vital pulp (P < 0.00001), a lower percentage of patients using postoperative analgesics (P < 0.00001), a longer onset times of pulpal anaesthesia and a longer duration of pulpal anaesthesia (P < 0.00001). In comparison with 2% lidocaine plus 1:80,000 adrenaline, 0.75% bupivacaine plus 1:200,000 adrenaline had same level of success rate (P = 0.29), and was better in postoperative pain control (P = 0.001) while 0.75% levobupivacaine had same level of postoperative pain control (P = 0.16); 0.5% levobupivacaine had higher success rate (P = 0.04) and was better in postoperative pain control (P = 0.001) than 2% lidocaine. There was no statistically significance in adverse events between two groups. Given the efficacy and safety, the bupivacaine group is better than the lidocaine group in dental operations that take a relatively long time, especially in endodontic treatments or where there is a need for postoperative pain management.

[Effects of different surface conditioning agents on the bond strength of resin-opaque porcelain composite].

The objective of this research is to evaluate the effects of different silane coupling agents on the bond strength between Ceramco3 opaque porcelain and indirect composite resin. Five groups of Co-Cr metal alloy substrates were fabricated according to manufacturer's instruction. The surface of metal alloy with a layer of dental opaque porcelain was heated by fire. After the surface of opaque porcelain was etched, five different surface treatments, i.e. RelyX Ceramic Primer (RCP), Porcelain Bond Activator and SE Bond Primer (mixed with a proportion of 1:1) (PBA), Shofu Porcelain Primer (SPP), SE bond primer (SEP), and no primer treatment (as a control group), were used to combine P60 and opaque porcelain along with resin cement. Shear bond strength of specimens was tested in a universal testing machine. The failure modes of specimens in all groups were observed and classified into four types. Selected specimens were subjected to scanning electron microscope and energy disperse spectroscopy to reveal the relief of the fracture surface and to confirm the failure mode of different types. The experimental results showed that the values of the tested items in all the tested groups were higher than that in the control group. Group PBA exhibited the highest value [(37.52 +/- 2.14) MPa] and this suggested a fact that all of the specimens in group PBA revealed combined failures (failure occurred in metal-porcelain combined surface and within opaque porcelain). Group SPP and RCP showed higher values than SEP (P < 0.05) and most specimens of SPP and RCP performed combined failures (failure occurred in bond surface and within opaque porcelain or composite resin) while all the specimens in group SEP and control group revealed adhesive failures. Conclusions could be drawn that silane coupling agents could reinforce the bond strength of dental composite resin to metal-opaque porcelain substrate. The bond strength between dental composite resin and dental opaque porcelain could meet the clinical requirements.

[Nitric oxide and prostaglandin E2 secretion in osteocytes induced by intermittent cyclic compressive force].

This paper is aimed to investigate the effect of rest-inserted loading on the mechanosensitivity of osteocytes. In the investigation, cultured MLO-Y4 osteocyte-like cells were strained on cyclic compressive force (CCF) by the self-made compressive loading device. Then we observed the effect of different rest periods-inserted loading (5 s, 15 s, 30 s, respectively) on the mechanosensitivity of osteocytes. We then determined the levels of secreted nitric oxide (NO) and prostaglandin E2 (PGE2) by Griess method and enzyme linked immunosorbent assay (ELISA), respectively. We then stained the cytoskeleton F-actin using immunofluorescence. We found that the expressions of NO and PGE2 in rest-inserted strained groups (> 15 s) were significantly increased compared to those in the continuous strained group. And rest-inserted loading promoted the parallel alignment of stress fibers. It indicates that rest-inserted loading could promote the mechanosensitivity of osteocytes, and this might be related to the parallel alignment of stress fibers.

How does crosstalk influence the jitter of a clock signal?

The stability and accuracy of the clock signal are crucial for the proper operation of various electronic devices and systems, as they directly impact system performance. In high-speed electronic systems, the clock signal is susceptible to interference by crosstalk. Therefore, evaluating the performance of the clock signal under crosstalk disturbance is important. Jitter, commonly used as an indicator to assess the degree of this interference, plays a significant role in this evaluation. In this paper, a method is proposed for assessing crosstalk-induced jitter (CIJ) based on scattering parameters. To verify the effectiveness of the method, CIJ was measured for clock signals with frequencies of 25, 100, and 156.25 MHz. In addition, the experimental results are well in agreement with the theoretical model. Thus, the potential application of this method is to assess the performance of circuits or electronic systems.

Dimethyl fumarate ameliorates chronic stress-induced anxiety-like behaviors by decreasing neuroinflammation and neuronal activity in the amygdala.

BACKGROUND: Chronic stress-induced neuroinflammation plays a pivotal role in the development and exacerbation of mental disorders, such as anxiety and depression. Dimethyl Fumarate (DMF), an effective therapeutic agent approved for the treatment of multiple sclerosis, has been widely reported to display anti-inflammatory and anti-oxidative effects. However, the impact of DMF on chronic stress-induced anxiety disorders and the exact underlying mechanisms remain largely unknown. METHODS: We established a mouse model of chronic social defeat stress (CSDS). DMF was administered orally 1 h before daily stress session for 10 days in CSDS + DMF group. qRT-PCR and western blotting were used to analyze mRNA and protein expression of NLRP3, Caspase-1 and IL-1ß. Immunofluorescence staining was carried out to detect the expression of Iba 1 and c-fos positive cells as well as morphological change of Iba 1+ microglia. Whole-cell patch-clamp recording was applied to evaluate synaptic transmission and intrinsic excitability of neurons. RESULTS: DMF treatment significantly alleviated CSDS-induced anxiety-like behaviors in mice. Mechanistically, DMF treatment prevented CSDS-induced neuroinflammation by inhibiting the activation of microglia and NLRP3/Caspase-1/IL-1ß signaling pathway in basolateral amygdala (BLA), a brain region important for emotional processing. Furthermore, DMF treatment effectively reversed the CSDS-caused disruption of excitatory and inhibitory synaptic transmission balance, as well as the increased intrinsic excitability of BLA neurons. CONCLUSIONS: Our findings provide new evidence that DMF may exert anxiolytic effect by preventing CSDS-induced activation of NLRP3/Caspase-1/IL-1ß signaling pathway and alleviating hyperactivity of BLA neurons.

Plasticity in resource allocation of the invasive Phytolacca americana: Balancing growth, reproduction, and defense along urban-rural gradients.

In response to varying environments along urban and rural gradients, invasive plants may strategically allocate resources to enhance their invasiveness. However, how invasive plants balance their resources for growth, reproduction, and defense as responses to biotic and abiotic factors across these gradients remain unclear. We conducted field surveys on the growth, reproduction, and herbivory of the invasive species Phytolacca americana across diverse urban and rural habitats. Leaf samples were collected to analyze the nutritional content, primary and secondary metabolites. We found that plant growth rates, specific leaf area, leaf nitrogen content, and concentrations of flavonoids and saponins were higher in urban habitats, while reproduction, herbivory, and carbon-to­nitrogen ratios were lower than those in rural habitats. We also found a trade-off between growth rate and herbivory, as well as trade-offs among defense traits associated with herbivory (e.g., leaf mass per area, the inverse of leaf nitrogen content, and carbon­nitrogen ratio) and the production of metabolites associated with abiotic stress tolerance (e.g., soluble sugars, flavonoids, and saponins). As earlier studies showed low levels of genetic diversity within and between populations, our findings suggest that the urban-rural gradient patterns of resource allocation are primarily phenotypic plasticity in response to herbivory in rural areas and abiotic factors in urban areas. Our study sheds light on the mechanisms by which urbanization affects plant invasions and offers insights for the implementation of their management strategies.

Determining the Clinical Characteristics, Treatment Strategies, and Prognostic Factors for Mycoplasma pneumoniae Encephalitis in Children: A Multicenter Study in China.

BACKGROUND AND PURPOSE: Most of the knowledge of Mycoplasma pneumonia (M. pneumoniae) encephalitis (MPE) in children is based on case reports or small case series. This study aimed to describe the clinical features and prognostic factors of MPE, and the efficacy of azithromycin with or without immunomodulatory therapy. METHODS: The medical data of 87 patients with MPE from 3 medical centers in southwestern China over a 7-year period were reviewed. RESULTS: MPE was found in children of all ages except for neonates. The most common neurological manifestations included consciousness disturbance (90%) and headache (87.4%), the most common extraneurological manifestations included fever (96.5%) and respiratory system involvement (94.3%); multisystem involvement (98.2%) and elevated C-reactive protein (CRP) (90.8%) were also prominent. M. pneumoniae was detected in cerebrospinal fluid (CSF) less often than in blood and respiratory tract secretions. Azithromycin with intravenous immunoglobulin or/and corticosteroid treatment can shorten the hospitalization duration and the clinical improvement process. Most patients (82.8%) received a favorable prognosis; serum lactate dehydrogenase (LDH) and CSF protein levels were higher in the poor-outcome group than in the good-outcome group (p<0.05). Neurological sequelae are likely to continue when the onset of this condition occurs during teenage years. CONCLUSIONS: MPE generally presented with nonspecific clinical manifestations. In children with acute encephalitis accompanied by multi-system involvement and prominently elevated CRP, M. pneumoniae should be considered as a possible pathogen. Immunomodulating therapies should be recommended regardless of the duration of the prodromal period. High CSF protein level, blood LDH elevation, and higher age may be associated with an unfavorable outcome.

How Does Ambient Temperature Fluctuation Influence the Short-Term Frequency Stability of OCXO?

Short-term frequency stability (STFS) is one of the most important specification of oven-controlled crystal oscillators (OCXOs). Although numerous studies have investigated factors that influence STFS, research on the impact of ambient temperature fluctuation is rare. This work investigates the relationship between the ambient temperature fluctuation and the STFS by introducing a model of the OCXO's short-term frequency-temperature characteristic (STFTC), which considers the transient thermal response of the quartz resonator, the thermal structure, and the oven control system. According to the model, an electrical-thermal co-simulation is adopted to determine the temperature rejection ratio of the oven control system and estimates the phase noise and Allan deviation (ADEV) that caused by fluctuations in ambient temperature. As a verification, a 10-MHz single-oven oscillator is designed. From the measured results, the estimated phase noise near the carrier agrees well with the measured results, and it can be seen that only when the temperature fluctuation is less than 10 mK at 1-100 s, the oscillator can maintain the characteristics of flicker frequency noise at the offset frequency from 10 mHz to 1 Hz, and the ADEV is possible to reach at the order of E -13 in 100 s. Thus, the model proposed in this study effectively predicts the impact of ambient temperature fluctuation on the STFS of an OCXO.

Stable Phase Equilibria of the Quaternary Water-Salt System Li+, Rb+, Mg2+//SO4 2--H2O at T = 273.2 K.

The phase equilibria for the quaternary system Li+, Rb+, Mg2+//SO4 2- - H2O at 273.2 K were studied by the isothermal dissolution equilibrium method. Based on the measured data, the space diagram, stable phase diagram, water content diagram, and the diagram of density vs composition are plotted. The stable phase diagram in the system consists of four quaternary invariant points, nine univariate curves, and six crystallization zones. For the invariant points, E1 and E4 belong to the commensurate type, and E2 and E3 belong to the incommensurate type. The order of the crystallization area is Rb2SO4·MgSO4·6H2O > 3Li2SO4·Rb2SO4·2H2O > Li2SO4·Rb2SO4 > MgSO4·7H2O > Li2SO4·H2O > Rb2SO4. The density of the equilibrium liquid changed regularly with the content of Rb2SO4 in the solution. By comparing the stable phase diagram of the partial ternary subsystems at T = 273.2 K and T = 298.2 K, it is found that the crystallization regions of Rb2SO4 increases with the decrease in temperature, which indicates that cooling is conducive to the crystallization of Rb2SO4. By comparing the stable phase diagram of the system at T = 273.2 K and T = 308.2 K, it was found that the system was composed of four invariant points, nine univariate curves, and six crystal regions. The double salt 3Li2SO4·Rb2SO4·2H2O is converted to 3Li2SO4·Rb2SO4. The crystallization region of single salt MgSO4·7H2O, Rb2SO4 and double salt Li2SO4·Rb2SO4 decreased obviously.

[Electroacupuncture mitigates hyperlipidemia via improving cholesterol metabolism mediated by SCAP/SREBP-2 signaling in liver tissue in rats].

OBJECTIVE: To explore the effect of electroacupuncture (EA) on sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP)/ SREBP-2 signaling and the expressions of its downstream cholesterol metabolism related molecules 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), and low-density lipoprotein receptor (LDLR) in the liver tissue in rats with hyperlipidemia (HLP), so as to reveal its mechanisms underlying improvement of HLP. METHODS: Male SD rats were randomly divided into normal control, HLP model and EA groups (n=10/group). The HLP model was established by feeding the rats with high-fat diet for 28 d. Rats in the EA group received EA stimulation (2 Hz/100 Hz, 2 mA) at "Fenglong" (ST40) and "Yinlingquan"(SP9) for 30 min, once daily for 28 d. The contents of total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) in the serum, the activity of glutamic oxaloacetic transaminase (AST) and glutamic pyruvic transaminase (ALT) were detected by automatic biochemical analysis. The content of TC in the liver tissue was detected using high performance liquid chromatography. The mRNA and protein expression levels of SCAP, SREBP-2, HMGCR, PCSK9 and LDLR in the liver tissue were measured by using quantitative real-time PCR and Western blot, respectively. The immunofluorescence density of liver SCAP was determined by using immunofluorescence histochemistry. RESULTS: Compared with the normal control group, the contents of liver TC, serum TC, LDL-C, the activities of AST and ALT, and the mRNA and protein expression levels of SCAP, SREBP-2, HMGCR, PCSK9 as well as SCAP immunoactivity were significantly increased (P<0.01), while the LDLR mRNA and protein levels were markedly decreased (P<0.01) in the model group. In comparison with the model group, the contents of liver TC， serum TC, LDL-C, the activities of AST and ALT and the expression of SCAP, SREBP-2, HMGCR, PCSK9 mRNAs and proteins and SCAP immunoactivity were considerably decreased in the EA group (P<0.01), while the LDLR protein level was evidently increased in the EA group (P<0.05). CONCLUSION: EA intervention can inhibit the synthesis of cholesterol in the liver and thus improve hyperlipidemia in HLP rats, which may be realized by down-regulating the protein and mRNA expressions of hepatic SCAP/SREBP-2, HMGCR and PCSK9, and up-regulating LDLR protein.

Cell wall breaking of Haematococcus pluvialis biomass facilitated by Baijiu jiuqu fermentation with simultaneously production of beverages.

The microalgae Haematococcus pluvialis is a commercial source of natural astaxanthin. However, mature cells develop rigid three-layer wall structures and a repulsive odor. This study applied a liquid static fermentation system to screen hydrolyzing microorganisms for cell wall hydrolysis. Baijiu jiuqu and Gutian hongqu were found to have promising potential for application. The fermentation using 2% baijiu jiuqu and 2% glucose for pre-activation achieved comparable recovery of carotenoids to homogenizer disruption methods and produced stable fragrance which may be attributed to ethyl octanoate, hexyl formate, and phenethyl butyrate, as revealed by gas chromatography-mass spectrometry analysis. The abundance of astaxanthin molecules was slightly affected by fermentation with fold change < 2, while molecules with higher fold change (>10) were mainly carbohydrates, lipids, and steroids proving the safety of the fermentation. This study provides a new scheme for the biorefining of Haematococcus. pluvialis, potentially contributing to the industrial production of natural astaxanthin.