Genetic mutation of Tas2r104/Tas2r105/Tas2r114 cluster leads to a loss of taste perception to denatonium benzoate and cucurbitacin B

Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.

Physiological Response and Resistance of Plants to Disease and Pest Stress

This paper outlines the physiological responses of plants to pathogenic microbial infection and pest feeding stress,as well as the resistance characteristics of plants to diseases and pests,and proposes new directions for future research on crop resistance to diseases and pests.The objective of this paper is to provide a reference framework for the breeding of crops with enhanced resistance to diseases and pests,the utilization of natural immunity in crops,and the efficient prevention and control of diseases and pests.This framework is intended to facilitate the healthy and sustainable development of the agricultural industry.

Characterization of genetic humanized mice with transgenic HLA DP401 or DRA but deficient in endogenous murine MHC classⅡgenes upon Staphylococcus aureus pneumonia

Background:Staphylococcus aureus can cause serious infections by secreting many superantigen exotoxins in“carrier”or“pathogenic”states.HLA DQ and HLA DR humanized mice have been used as a small animal model to study the role of two molecules during S.aureus infection.However,the contribution of HLA DP to S.aureus infection is unknown yet.Methods:In this study,we have produced HLA DP401 and HLA DRA0101 humanized mice by microinjection of C57BL/6J zygotes.Neo-floxed IAβ+/-mice were crossbred with Ella-Cre and further crossbred with HLA DP401 or HLA-DRA0101 humanized mice.After several rounds of traditional crossbreeding,we finally obtained HLA DP401-IAβ-/-and HLA DRA-IAβ-/-humanized mice,in which human DP401 or DRA0101 molecule was introduced into IAβ-/-mice deficient in endogenous murine MHC classⅡmolecules.A transnasal infection murine model of S.aureus pneumonia was induced in the humanized mice by administering 2×108CFU of S.aureus Newman dropwise into the nasal cavity.The immune responses and histopathology changes were further assessed in lungs in these infected mice.Results:We evaluated the local and systemic effects of S.aureus delivered intranasally in HLA DP401-IAβ-/-and HLA DRA-IAβ-/-transgenic mice.S.aureus Newman infection significantly increased the m RNA level of IL 12p40 in lungs in humanized mice.An increase in IFN-γand IL-6 protein was observed in HLA DRA-IAβ-/-mice.We observed a declining trend in the percentage of F4/80+macrophages in lungs in HLA DP401-IAβ-/-mice and a decreasing ratio of CD4+to CD8+T cells in lungs in IAβ-/-mice and HLA DP401-IAβ-/-mice.A decreasing ratio of Vβ3+to Vβ8+T cells was also found in the lymph node of IAβ-/-mice and HLA DP401-IAβ-/-mice.S.aureus Newman infection resulted in a weaker pathological injury in lungs in IAβ-/-genetic background mice.Conclusion:These humanized mice will be an invaluable mouse model to resolve the pathological mechanism of S.aureus pneumonia and study what role DP molecule plays in S.aureus infection.

The Characteristics of the Shear-Vibrating Quartz Crystal Resonator

<正>According to the piezoelectric equation and the vibration theory of the quartz crystal,the relations between the vibrating frequency and structural parameters under the thickness-shear-vibration of AT-cut quartz crystal have been studied. The frequency conditions under which quartz crystal resonator formed stationary wave inside the electrode district and the transmission characteristics of wave outside the electrode district have also been discussed.A quartz crystal resonator was developed based on this analysis.The experiment showed that the force-sensing characteristics were independent of the fixation of the crystal edge.The detecting distinguish ability was up to 0.001°,and the short-term frequency stability was up to 1.38×10~ (-10)/min.

New celestial assisted INS initial alignment method for lunar explorer

In the future lunar exploration programs of China, soft landing, sampling and returning will be realized. For lunar explorers such as Rovers, Landers and Ascenders, the inertial navigation system （INS） will be used to obtain high-precision navigation information. INS propagates position, velocity and attitude by integration of sensed accelerations, so initial alignment is needed before INS can work properly. However, traditional ground-based initial alignment methods cannot work well on the lunar surface because of its low rotation rate （0.55°/h）. For solving this problem, a new autonomous INS initial alignment method assisted by celestial observations is proposed, which uses star observations to help INS estimate its attitude, gyroscopes drifts and accelerometer biases. Simulations show that this new method can not only speed up alignment, but also improve the alignment accuracy. Furthermore, the impact factors such as initial conditions, accuracy of INS sensors, and accuracy of star sensor on alignment accuracy are analyzed in details, which provide guidance for the engineering applications of this method. This method could be a promising and attractive solution for lunar explorer＇s initial alignment.

The Synthesis of Pyridine 2,6-dicarboxylic Acid Using Microwave Irradiation

This research took 2,6-dimethylpyridine as raw materials under microwave irradiation to syntheses pyridine 2,6-dicarboxylic acid by adding oxidation potassium permanganate. However, there are lots of factors affecting the yield including the amount of potassium permanganate and sulfuric acid, reaction time, power, 2,6-dimethylpyridine dosage. We made the further research, using orthogonal experiment to find the optimal process conditions. Thus our research changed the synthesis process from a traditional method to a new type of microwave technology.

Maillard Products Formed from Chicken Fat Oxidants and Amino Acids Act as a Flavor Enhancer in Comminuted Chicken Products

Lipid oxidation and degradation are generally recognized as unfavorable reactions in food processing. However, lipids can be utilized to produce meat-like flavorings through reaction with amino acids after degradation to carbonyls such as aldehydes and ketones. The fatty acids in chicken fat mainly comprise palmitic acid, oleic acid and linoleic acid. After being heated at 120 ~C for 3 h, the degraded carbonyls of chicken fat were reacted with cysteine, alanine, glycine and thiamine to form a chicken-like flavoring. The key aromatic components of the flavoring were identified by GC-MS. In the overall volatile profile, 22 kinds of compound were detected, among which 2-furanmethanol was formed by the Maillard reaction, 1-（2-furanyl）-ethanone by cyclization and 2,4,6-trimethyl-l,3,5-trithiane by the Strecker degradation of cysteine. Dihydro-2-methyl-3（2H）-furanone, dihydro-2-methyl- 3（2H）-thiophenone, 2-acetyl-lH-pyrroline and 4-methyl-5-thiazoleethanol were the degradation products of thiamine. The prepared chicken flavoring was added to comminuted chicken product （CCP）. GC-MS analysis and sensory evaluation showed that the flavor and odor of the CCP were greatly enhanced.

Long-term effect of stenting in unprotected left main coronary artery disease in the elderly

Objective To evaluate the feasibility,safety and efficacy of percutaneous stent implantation for treating left main coronary artery(LMCA)stenosis.Methods Consecutive patients with unprotected left main coronary artery disease treated by stent-based percutaneous intervention(PCI)at 6 medical centers in China were enrolled.Procedural data and clinical outcomes were obtained from all patients.Results From January 2001 to December 2004,138 patients(79 males and 59 females;mean age:69.7±5.8 years)underwent PCI for LMCA stenosis.Bare metal stents(BMS)were implanted in 51 patients with non-bifurcational lesions and in 5 patients with bifurcational lesions from January of 2001 to June of 2003(BMS group);.Drug eluting stents(DES)were used unselectively to cover both bifurcational and non-bifurcational lesions in 86 patients from July of 2003 to December of 2004(DES group).Procedural success rate of the 138 cases was 98%(135/138).One patient(0.7%)with bifurcation lesion who was treated with DES died from severe heart failure 2 weeks after the procedure.During a mean follow up period of 21.3±5.6 months,one patient died from renal failure,one from sudden cardiac death,4 underwent target lesion revascularization(TLR)in the BMS group,which all occurred in patients with bifurcational lesions;whereas in the DES group no deaths occurred and only one patient with bifurcational lesion had TLR.Conclusions(1)PCI is feasible and relatively safe to treat unprotected left main coronary artery disease in elderly patients at medical centers with experienced professionals.(2)BMS and DES have similar immediate and long-term efficacy in the treatment of ostium and shaft lesions of the LMCA.(3)DES are strongly suggested in the therapy of distal bifurcation lesion of unprotected LMCA.

Synthesis of 2,6-pyridine Dimethyl Formate under Microwave Irradiation

An efficient synthesis of 2,6-pyridine dimethyl formate happened under the microwave irradiation is proposed. It is noteworthy that some factors influence the product yield such as time, temperature, ratio of reactants, and acidity which were discussed. The optimized quantity of 2,6-pyridine dimethyl acid is 10 mmol and methanol is 25 mmol. The yield is up to 95%-96% when using 2 mL 30% sulfuric acid. All products have been characterized by IR and 1H NMR.

The AHP analysis on Quality Evaluation oriented to Bilingual Teaching Practices in Yunnan＇ s Universities

A number of studies show that bilingual education in private universities is worth studying in recent years, but its feasibility causes many debates at the same time which students are not as superior in both English proficiency and expertise as what we have expect- ed.However, it is undeniable that teaching process of teachers becomes significant influence on students＇ learning results. In my research I focus on the comprehensive view and procedures of teaching and set up the index system for evaluation of bilingual teaching process from teachers＇ perspective. In addition, I calculate the weighted value of each index at each level by using the root method, and determine the key success factors which affecting the quality of bilingual teaching process. Lastly, taking Oxbridge college as an example, I try to study what types of factors that constitutes conditions and limitations for a successful effect for bilingual teaching and to propose the solutions for improving and self-supervising in bilingual teaching process.

The Anti-Vibrating-Impact Research of the Piezoelectric Resonator Force Sensor

Based on the analysis of one-dimension inertial accelerometer movement model,from which the resolution of the accelerometer inertial mass displacement equation was derived,the response of the sensor sensing element to vibration and impact of various frequencies was studied.The theoretical and experimental results show that a reasonable configuration among the sensing element inherent frequency,environmental exciting frequency and the damp factors of the sensor is the key to prevent the sensor from damage.The sensor has good anti-vibrating impact ability when the relative damp factor is 0.7,and the environmental interferential vibrating frequency is less than 0.35 times of the inherent frequency of the sensing element.

Placement optimization of Multi-Type fault current limiters based on genetic algorithm

The fault current limiter(FCL)is an effective measure for improving system stability and suppressing short-circuit fault current.Because of space and economic costs,the optimum placement of FCLs is vital in industrial applications.In this study,two objectives with the same dimensional measurement unit,namely,the total capital investment cost of FCLs and circuit breaker loss related to short-circuit currents,are considered.The circuit breaker loss model is developed based on the attenuation rule of the circuit breaker service life.The circuit breaker loss is used to quantify the current-limiting effect to avoid the problem of weight selection in a multi-objective problem.The IEEE 10-generator 39-bus system in New England is used to evaluate the performance of the proposed genetic algorithm(GA)method.Comparative and sensitivity analyses are performed.The results of the optimized plan are validated through simulations,indicating the significant potential of the GA for such optimization.

Experimental generation and observation of a super-resolution optical tube

We generated a super-resolution optical tube by tightly focusing a binary phase modulated azimuthally polarized laser beam.The binary phase modulation is achieved by a glass substrate with multi-belt concentric ring grooves.We also characterized the 3D beam pro¯le by using a crossshaped knife-edge fabricated on a silicon photo-detector.The size of the super-resolution dark spot in the tube is 0.32
,which remains unchanged for
4
within the tube.This optical tube may¯nd applications in super-resolution microscopy,optical trapping and particle acceleration.

A Novel Extraction Method of Baicalin from Radix Scutellariae

A novel extraction method of baicalin from radix scutellariae was explored in this study. Liquid-liquid continuous biphasic extraction was a new method, and showed the advantage of high extracting contents of total flavone compared with one of the traditional methods. The novel extraction method which is easy to operate and has good reproducibility was much more effective than the traditional one.

Efficacy and safety of bilastine vs.levocetirizine for the treatment of chronic idiopathic urticaria:A multicenter,double-blind,double-dummy,phase III,non-inferiority,randomized clinical trial

To the Editor:Chronic urticaria,prevalent globally and increasing in China,predominantly affects young and middle-aged women,impacting their quality of life(QoL).[1]Standard treatment involves second-generation H1 antihistamines,with bilastine showing promise due to its selective action and minimal side effects.However,direct comparative studies are scarce,particularly in the Chinese population.We aimed to evaluate the efcacy and safety of bilastine compared to levocetirizine in Chinese patients.

Architecture design and advanced manufacturing of heart-on-a-chip:scaffolds,stimulation and sensors

Heart-on-a-chip(HoC)has emerged as a highly efficient,cost-effective device for the development of engineered cardiac tissue,facilitating high-throughput testing in drug development and clinical treatment.HoC is primarily used to create a biomimetic microphysiological environment conducive to fostering the maturation of cardiac tissue and to gather information regarding the real-time condition of cardiac tissue.The development of architectural design and advanced manufacturing for these“3S”components,scaffolds,stimulation,and sensors is essential for improving the maturity of cardiac tissue cultivated on-chip,as well as the precision and accuracy of tissue states.In this review,the typical structures and manufacturing technologies of the“3S”components are summarized.The design and manufacturing suggestions for each component are proposed.Furthermore,key challenges and future perspectives of HoC platforms with integrated“3S”components are discussed.

MYC promotes global transcription in part by controlling P-TEFb complex formation via DNA-binding independent inhibition of CDK9 SUMOylation

MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC mutants to dissect the molecular basis for MYC-driven global transcription. We found that MYC mutants deficient in DNA binding or known transcriptional activation activities can still promote global transcription and enhance serine 2 phosphorylation(Ser2P) of the RNA polymerase(Pol) II Cterminal domain(CTD), a hallmark of active elongating RNA Pol II. Two distinct regions within MYC can promote global transcription and Ser2P of Pol II CTD. The ability of various MYC mutants to promote global transcription and Ser2P correlates with their ability to suppress CDK9 SUMOylation and enhance positive transcription elongation factor b(P-TEFb) complex formation. We showed that MYC suppresses CDK9 SUMOylation by inhibiting the interaction between CDK9 and SUMO enzymes including UBC9 and PIAS1. Furthermore, MYC's activity in enhancing global transcription positively contributes to its activity in promoting cell proliferation and transformation. Together, our study demonstrates that MYC promotes global transcription, at least in part, by promoting the formation of the active P-TEFb complex via a sequence-specific DNA-binding activity-independent manner.

右位心的患病阈值和多因素遗传模式

右位心指正常生长于左侧的心脏位置或方向发生异常,常伴发复杂的先天性心脏病(先心),发病率约为十万分之八大规模小鼠表型的正向遗传学筛查表明,纤毛基因在先心的发病机制中起着关键作用。然而,右位心这类复杂先天性畸形的遗传模式,其中的遗传病因是否受纤毛基因驱动,以及适用于复杂性状的“全基因”模型能否解释尚不清楚。基于194名右位心患者及对照样本全基因组外显子测序的遗传学分析发现,“单例功能丧失性变异”(Singletonlossof functionvariant,SLoFV)的总数目与右位心显著相关(P=6.4x10-49).当个体携带的SLoFV个数大于8时,携带者发生右位心的风险呈指数增加。进一步通过斑马鱼模型,发现敲降心脏特异性高表达的核心基因,导致心脏结构的致畸率显著高于其他类型的相关基因.结果表明右位心存在基于SLoFV的全基因组遗传风险阈值,并证实了不同权重基因对心脏致畸的不同效应,丰富了全基因组模型下对核心基因遗传效应的理解,为理解复杂疾病右位心的遗传发病机制提供新的理论基础。

Feasible fabrication of o-phenanthroline-based polymer adsorbent for selective capture of aqueous Ag(Ⅰ)

Devising a desirable adsorbent for efficiently selective capture of Ag(Ⅰ) from wastewater has attracted much attention but faced with huge challenges. Herein, a novel linear o-phenanthroline-based polymer L-PRL was prepared via chemical oxidative polymerization for the adsorption of Ag(Ⅰ). The maximum adsorption capacity for Ag(Ⅰ) by L-PRL is 325.8 mg/g at pH 0. In addition, L-PRL owes ascendant selectivity for Ag(Ⅰ) from aqueous solutions containing various interfering metal ions of Pb(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cd(Ⅱ)and Fe(Ⅲ). Multiple characterizations of FT-IR and XPS uncover that the N groups on L-PRL act as adsorption sites to coordinate with Ag(Ⅰ). Density functional theory(DFT) calculations further evidence the mechanism that L-PRL is provided with the admirable adsorptivity and selectivity for Ag(Ⅰ). It is mainly attributed to the most stable complexes of L-PRL with Ag(Ⅰ), which possesses shortest Ag-N bond length compared with other heavy metal ions. Furthermore, 93.5% of initial adsorption capacity is reserved after four continuous regeneration cycles, indicating that L-PRL is equipped with superior recyclability and durability, and L-PRL is capable of removing Ag(Ⅰ) in low-concentration actual Ag(Ⅰ)-containing wastewater completely. This study shed light on the rational design of polymer adsorbents and in-depth insight into selective removal of aqueous Ag(Ⅰ).

Effects of elevation on spring phenological sensitivity to temperature in Tibetan Plateau grasslands

Vegetation phenology is an important indicator of climate change impacts on the seasonal dynamics of the biosphere. However, little is known about the influence of elevation on spring phenological sensitivity to temperature in an alpine ecosystem. Based on remotely sensed land surface phenology and temperature data from 2001 to2010, this study investigated the rate of spring phenological change of the Tibetan Plateau(TP) grasslands in response to interannual temperature variations at different elevations. Results suggest that spring phenology in the TP grasslands exhibits a stronger response to changes in temperature at higher elevations than at lower ones. In particular, spring phenology advanced by 1–2 days in response to a 1 °C increase in May average temperature at elevations from 3,000 to 3,500 m, while the rate was up to8–9 days/°C at 5,000–5,500 m. Analysis using accumulated growing degree days(AGDD) from January 1through May 31 showed the same general trend with increased elevation associated with increased sensitivity(as measured by phenological change per unit of AGDDchange). Such temperature sensitivity gradients in the TP grasslands could be partly explained by the growth efficiency hypothesis which suggests that vegetation adapted to colder climates likely requires less heat energy for the onset of growing season and vice versa in warmer climates.Furthermore, accumulated growing degree days from January 1 to the greenup date were found to decrease with increasing elevations, which provided evidence to support the applicability of the growth efficiency hypothesis in an alpine grassland ecosystem.