Cre-recombinase systems for induction of neuronspecific knockout models:a guide for biomedical researchers

Gene deletion has been a valuable tool for unraveling the mysteries of molecular biology.Early approaches included gene trapping and gene targetting to disrupt or delete a gene randomly or at a specific location,respectively.Using these technologies in mouse embryos led to the generation of mouse knocko ut models and many scientific discoveries.The efficacy and specificity of these approaches have significantly increased with the advent of new technology such as cluste red regula rly inters paced short palindromic repeats for targetted gene deletion.However,several limitations including unwanted off-target gene deletion have hindered their widespread use in the field.Crerecombinase technology has provided additional capacity for cell-specific gene deletion.In this review,we provide a summary of currently available literature on the application of this system for targetted deletion of neuronal genes.This article has been constructed to provide some background info rmation for the new trainees on the mechanism and to provide necessary information for the design,and application of the Cre-recombinase system thro ugh reviewing the most f requent promoters that are currently available for genetic manipulation of neuro ns.We additionally will provide a summary of the latest technological developments that can be used for targeting neurons.This may also serve as a general guide for the selection of appropriate models for biomedical research.

Production of antihypertensive and antidiabetic peptide fractions from quinoa(Chenopodium quinoa Willd.)by electrodialysis with ultrafi ltration membranes

Processing bioactive peptides from natural sources using electrodialysis with ultrafiltration membranes(EDUF)have gained attention since it can fractionate in terms of their charge and molecular weight.Quinoa is a pseudo-cereal highlighted by its high protein content,amino acid profile and adapting growing conditions.The present work aimed at the production of quinoa peptides through fractionation using EDUF and to test the fractions according to antihypertensive and antidiabetic activity.Experimental data showed the production of peptides ranging between 0.4 and 1.5 k Da.Cationic(CQPF)(3.01%),anionic(AQPF)(1.18%)and the electrically neutral fraction quinoa protein hydrolysate(QPH)-EDUF(~95%)were obtained.In-vitro studies showed the highest glucose uptake modulation in L6 cell skeletal myoblasts in presence of QPH-EDUF and AQPF(17%and 11%)indicating potential antidiabetic activity.The antihypertensive effect studied in-vivo in spontaneously hypertensive rats(SHR),showed a decrease in systolic blood pressure in presence of the fractionated peptides,being 100 mg/kg a dose comparable to Captopril(positive control).These results contribute to the current knowledge of bioactive peptides from quinoa by reporting the relevance of EDUF as tool to produce selected peptide fractions.Nevertheless,further characterization is needed towards peptide sequencing,their respective role in the metabolism and scaling-up production using EDUF.

The Neurologist in the Emergency Room: Prospective Study of the Neurological Emergency Group in Lombardia

Purpose of the work was to quantify the workloads and the neurologist’s commitment in ER, to verify the management of urgencies and appropriateness of neurological counseling requests. Neurologic emergencies are frequent in elderly patients and are associated with high morbidity and mortality. Due to the aging population, neurologic pathologies in emergency room (ER) are widely expected to increase. The role of the neurologist in this context is controversial. Methods: in 14 operative units of neurology a prospective collection of neurological evaluations in ER was carried out using boards of detection of the most frequent neurological clinical pictures seen in the course of a week. Data were collected from 738 cases. Attention was focused on cerebrovascular diseases (CVD), impairment of consciousness, epilepsy, headache, dizziness, head trauma and disorders of the peripheral nervous system (PNS). Achievements: neurological consultations were on average 5% of total accesses to ER. The most common pathology seen was ischemic stroke. After counseling most patients were discharged home. The CVD required the greatest commitment to the specialist. The usefulness of the specialized neurological “filter” has been confirmed in a non-simple operative context, aimed at optimizing the appropriateness of the hospitalization and the economy of the diagnostic path.

Combination of corticosteroids and 5-aminosalicylates or corticosteroids alone for patients with moderate-severe active ulcerative colitis:A global survey of physicians'practice

AIM To examine treatment decisions of gastroenterologists regarding the choice of prescribing 5-aminosalycilates(5ASA) with corticosteroids(CS) versus corticosteroids alone for patients with active ulcerative colitis(UC). METHODS A cross-sectional questionnaire exploring physicians' attitude toward 5ASA + CS combination therapy vs CS alone was developed and validated. The questionnaire was distributed to gastroenterology experts in twelve countries in five continents. Respondents' agreement with stated treatment choices were assessed by standardized Likert scale. Background professional characteristics of respondents were analyzed for correlation with responses. RESULTS Six hundred and sixty-four questionnaires were distributed and 349 received(52.6% response rate). Of 340 eligible respondents, 221(65%) would continue 5ASA in a patient hospitalized for intravenous CS treatment due to a moderate-severe UC flare, while 108(32%) would stop the 5ASA(P < 0.001), and 11(3%) are undecided. Similarly, 62% would continue 5ASA in an out-patient starting oral CS. However, only 140/340(41%) would proactively start 5ASA in a hospitalized patient not receiving 5ASA before admission. Most(94%) physicians consider the safety profile of 5ASA as very good. Only 52% consider them inexpensive, 35% perceive them to be expensive and 12% are undecided. On multi-variable analysis, less years of practice and perception of a plausible additive mechanistic effect of 5ASA + CS were positively associated with the decision to continue 5ASA with CS. CONCLUSION Despite the absence of data supporting its benefit, most gastroenterologists endorse combination of 5ASA + CS for patients with active moderate-to-severe UC. Randomized controlled trials are needed to assess if 5ASA confer any benefit for these patients.

Sintering behavior of combusted iron powder in a packed bed reactor with nitrogen and hydrogen

Sintering behavior of micron-sized combusted iron powder is studied in a packed bed reactor,at various temperatures under inert(nitrogen)and reducing(hydrogen)conditions.Compression tests are subsequently used to quantify the degree of sintering.A sintering model,based on the formation of a solid bridge through solid state surface diffusion of iron atoms,matches the experimental results.Sintering of combusted iron occurs at temperatures≥575°C in both nitrogen and hydrogen atmospheres and increases exponentially with temperature.The observed decrease in reduction rate at high temperatures is not caused by the sintering process but by the formation of wüstite as an intermediate species,leading to the formation of a dense iron layer.Iron whiskers form at high temperatures(≥700°C)in combination with low reduction rates(≤25 vol%H2),leading to the production of sub-micron fines.

3D free-assembly modular microfluidics inspired by movable type printing

Reconfigurable modular microfluidics presents an opportunity for flexibly constructing prototypes of advanced microfluidic systems.Nevertheless,the strategy of directly integrating modules cannot easily fulfill the requirements of common applications,e.g.,the incorporation of materials with biochemical compatibility and optical transparency and the execution of small batch production of disposable chips for laboratory trials and initial tests.Here,we propose a manufacturing scheme inspired by the movable type printing technique to realize 3D free-assembly modular microfluidics.Double-layer 3D microfluidic structures can be produced by replicating the assembled molds.A library of modularized molds is presented for flow control,droplet generation and manipulation and cell trapping and coculture.In addition,a variety of modularized attachments,including valves,light sources and microscopic cameras,have been developed with the capability to be mounted onto chips on demand.Microfluidic systems,including those for concentration gradient generation,droplet-based microfluidics,cell trapping and drug screening,are demonstrated.This scheme enables rapid prototyping of microfluidic systems and construction of on-chip research platforms,with the intent of achieving high efficiency of proof-of-concept tests and small batch manufacturing.

Combining flamelet-generated manifold and machine learning models in simulation of a non-premixed diffusion flame

Flamelet Generated Manifold(FGM)is an example of a chemistry tabulation or a flamelet method that is under attention because of its accuracy and speed in predicting combustion characteristics.However,the main problem in applying the model is a large amount of memory required.One way to solve this problem is to apply machine learning(ML)to replace the stored tabulated data.Four different machine learning methods,including two Artificial Neural Networks(ANNs),a Random Forest(RF),and a Gradient Boosted Trees(GBT),are trained,validated,and compared in terms of various performance measures.The progress variable source term and transport properties are replaced with the ML models.Particular attention was paid to the progress variable source term due to its high gradient and wide range of its value in the control variables space.Data preprocessing is shown to play an essential role in improving the performance of the models.Two ensemble models,namely RF and GBT,exhibit high training efficiency and acceptable accuracy.On the other hand,the ANN models have lower training errors and take longer to train.The four models are then combined with a one-dimensional combustion code to simulate a counterflow non-premixed diffusion flame in engine-relevant conditions.The predictions of the ML-FGM models are compared with detailed chemical simulations and the original FGM model for key combustion properties and representative species profiles.

Non-anatomical liver resection for hepatocellular carcinoma:the SegSubTe classification to overcome the problem of heterogeneity

Background:The superiority of anatomical resection(AR)vs.non-anatomical resection(NAR)in the surgical management of hepatocellular carcinoma(HCC)is debated.ARs are well-defined procedures,whereas the lack of NAR standardization results in heterogeneous outcomes.This study aimed to introduce the SegSubTe classification for NAR detailing the appropriateness of the level of surgical section of the Glissonean pedicles feeding the tumor.Methods:A single-center retrospective analysis of pre-and postoperative imaging of consecutive patients treated with NAR for single HCC between 2012 and 2020 was conducted.The quality of surgery was assessed classifying the type of vascular supply and the level of surgical section(segmental,subsegmental or terminal next to the tumor)of vascular pedicles feeding the HCCs;then,the population was divided in“SegSubTe-IN”or“SegSubTe-OUT”groups,and the tumor recurrence and survival were analyzed.Results:Ninety-seven patients who underwent NAR were included;76%were SegSubTe-IN and 24%were SegSubTe-OUT.Total disease recurrence,local recurrence and cut-edge recurrence in the SegSubTe-IN vs.SegSubTe-OUT groups were 50%vs.83%(P=0.006),20%vs.52%(P=0.003)and 16%vs.39%(P=0.020),respectively.SegSubTe-OUT odds ratio for local recurrence was 4.1 at univariate regression analysis.One-,three-,and five-year disease-free survival rates in the SegSubTe-IN vs.SegSubTe-OUT groups were 81%,58%and 35%vs.46%,21%and 11%,respectively(P<0.001).Conclusions:The SegSubTe classification is a useful tool to stratify and standardize NAR for HCC,aiming at improving long-term oncological outcomes and reducing the heterogeneity of quality of NAR for HCC.

基于路径混淆的实时轨迹隐私保护方法

由于传统的轨迹隐私保护算法在处理实时问题时的局限性,针对实时轨迹的隐私保护处理提出了基于路径混淆的轨迹隐私保护算法。该算法能够解决传统路径混淆算法中出现的轨迹数据不足和轨迹数据可用性的问题。利用车辆自适应时间窗口算法对车辆轨迹进行分组选择,通过混淆算法提高轨迹的隐私保护效果,在混淆过程中目标车辆与周围车辆形成混淆组从而达到多轨迹的真假混淆情况。通过对比实验分析了轨迹数据的可用性,验证所提出算法比其他传统方法在车辆隐私保护方面效果更好,且混淆后轨迹数据可用性更高。

Modification of Nano-α-Al2O3 and Its Influence on the Surface Properties of Waterborne Polyurethane Resin Composite Passivation Films

Silane coupling agent KH560 was used to modify the surface of nano-α-Al2O3 in ethanol-aqueous solution with different proportions. The particle size of nano-α-Al2O3 was determined by nano-particle size analyzer, and the effects of nano-α-Al2O3 content, ethanol-aqueous solution ratio and KH560 dosage on the dispersion and particle size of nano-α-Al2O3 were investigated. The material structure before and after modification was determined by Fourier transform infrared spectroscopy (FTIR). Aqueous polyurethane resin and inorganic components are combined with modified nano-α-Al2O3 dispersion to form chromium-free passivation solution. The solution is coated on the galvanized sheet, the adhesion and surface hardness are tested, the bonding strength of the coating and the surface hardness of the substrate are discussed. The corrosion resistance and surface morphology of the matrix were investigated by electrochemical test, neutral salt spray test and scanning electron microscope test. The chromium-free passivation film formed after the modification of nano-α-Al2O3 increases the surface hardness of galvanized sheet by about 85%. The corrosion resistance of the film is better than that of a single polyurethane film. The results show that the surface hardness and corrosion resistance of polyurethane resin composite passivation film are significantly improved by the introduction of nano-α-Al2O3.

汽车行业冲压产品开发过程精度管理

分析了汽车行业产品开发过程精度管理现状,主要是产品开发周期短,同时精度管理相对弱化。但冲压产品精度对整车的影响是长久的和深远的,所以,需要进行更加精细化管理。从模具工艺设计到产品量产的各个过程,介绍了精度管理的要点项目和管理方法。

Artificial intelligence for characterization of diminutive colorectal polyps:A feasibility study comparing two computer-aided diagnosis systems

BACKGROUND Artificial intelligence(AI)has potential in the optical diagnosis of colorectal polyps.AIM To evaluate the feasibility of the real-time use of the computer-aided diagnosis system(CADx)AI for ColoRectal Polyps(AI4CRP)for the optical diagnosis of diminutive colorectal polyps and to compare the performance with CAD EYE^(TM)(Fujifilm,Tokyo,Japan).CADx influence on the optical diagnosis of an expert endoscopist was also investigated.METHODS AI4CRP was developed in-house and CAD EYE was proprietary software provided by Fujifilm.Both CADxsystems exploit convolutional neural networks.Colorectal polyps were characterized as benign or premalignant and histopathology was used as gold standard.AI4CRP provided an objective assessment of its characterization by presenting a calibrated confidence characterization value(range 0.0-1.0).A predefined cut-off value of 0.6 was set with values<0.6 indicating benign and values≥0.6 indicating premalignant colorectal polyps.Low confidence characterizations were defined as values 40%around the cut-off value of 0.6(<0.36 and>0.76).Self-critical AI4CRP’s diagnostic performances excluded low confidence characterizations.RESULTS AI4CRP use was feasible and performed on 30 patients with 51 colorectal polyps.Self-critical AI4CRP,excluding 14 low confidence characterizations[27.5%(14/51)],had a diagnostic accuracy of 89.2%,sensitivity of 89.7%,and specificity of 87.5%,which was higher compared to AI4CRP.CAD EYE had a 83.7%diagnostic accuracy,74.2%sensitivity,and 100.0%specificity.Diagnostic performances of the endoscopist alone(before AI)increased nonsignificantly after reviewing the CADx characterizations of both AI4CRP and CAD EYE(AI-assisted endoscopist).Diagnostic performances of the AI-assisted endoscopist were higher compared to both CADx-systems,except for specificity for which CAD EYE performed best.CONCLUSION Real-time use of AI4CRP was feasible.Objective confidence values provided by a CADx is novel and self-critical AI4CRP showed higher diagnostic performances compared to AI4CRP.

Micro-encapsulated essential oils and organic acids combination improves intestinal barrier function,inflammatory responses and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli F4(K88^+)

This study evaluated the effects of micro-encapsulated(protected)organic acids(OA)and essential oils(EO)combination,P(OA+EO),and effects of a regular blend of free acids(FA)on the growth,immune responses,intestinal barrier and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli(ETEC)F4(K88^+).A total of 30 crossbred(Duroc×Landrace×Large White)weaned barrows(7.41±0.06 kg,28 d old)were assigned randomly to 5 treatments:1)non-challenged positive control(PC),2)ETEC F4(K88^+)-challenged negative control(NC),3)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+free acidifier(FA)at 5 g/kg,4)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+P(OA+EO)at 1 g/kg(P1),5)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+P(OA+EO)at 2 g/kg(P2).Each dietary treatment had 6 replicates of one piglet each and the study lasted for 3 wk.On d 7,pigs in NC,FA,P1 and P2 were orally dosed with 10 mL of ETEC F4(K88^+)culture(1×10^9 CFU/mL).From d 7 to 14 after the ETEC F4(K88^+)challenge,P1 increased gain-to-feed ratio(G:F)significantly(P<0.05)compared with NC and FA groups.From d 14 to 21,P2 increased the average daily gain of pigs(P<0.05)compared with NC and FA groups.Compared with NC,P2 reduced tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-10 concentrations(P<0.05)in sera collected at 4 h later after ETEC F4(K88^+)challenge.On d 21,P1 increased occludin and zonula occludens-1 protein expression in ileum compared with NC(P<0.05).After this 3-wk experiment,alpha diversity of gut microbiota was decreased by P2 compared with PC,and P1 increased the relative abundance of Lactobacillus in ileum,cecum and colon(P<0.05).In co nclusio n,dietary P(OA+EO)additive at 2 g/kg combined with antibiotics could improve piglet performance and attenuate inflammation,and P(OA+EO)additive at 1 g/kg combined with antibiotics improved intestinal barrier and increased beneficial microbiota composition after an F4(K88^+)challenge.

Quantum dot mode-locked frequency comb with ultra-stable 25.5 GHz spacing between 20℃ and 120℃

Semiconductor mode-locked lasers(MLLs)are promising frequency comb sources for dense wavelength-divisionmultiplexing(DWDM)data communications.Practical data communication requires a frequency-stable comb source in a temperature-varying environment and a minimum tone spacing of 25 GHz to support high-speed DWDM transmissions.To the best of our knowledge,however,to date,there have been no demonstrations of comb sources that simultaneously offer a high repetition rate and stable mode spacing over an ultrawide temperature range.Here,we report a frequency comb source based on a quantum dot(QD)MLL that generates a frequency comb with stable mode spacing over an ultrabroad temperature range of 20–120℃.The two-section passively mode-locked In As QD MLL comb source produces an ultra-stable fundamental repetition rate of 25.5 GHz(corresponding to a 25.5 GHz spacing between adjacent tones in the frequency domain)with a variation of 0.07 GHz in the tone spacing over the tested temperature range.By keeping the saturable absorber reversely biased at-2 V,stable mode-locking over the whole temperature range can be achieved by tuning the current of the gain section only,providing easy control of the device.At an elevated temperature of 100℃,the device shows a 6 d B comb bandwidth of 4.81 nm and 31 tones with>36 d B optical signal-to-noise ratio.The corresponding relative intensity noise,averaged between 0.5 GHz and 10 GHz,is-146 d Bc∕Hz.Our results show the viability of the In As QD MLLs as ultra-stable,uncooled frequency comb sources for low-cost,large-bandwidth,and low-energy-consumption optical data communications.

粮仓哲学--对储粮科技走向智慧化的哲学思考

关于科学技术影响认知变化的探索由来已久,分别形成科学哲学和技术哲学。我国储粮技术发展,经历了改革开放前的初探、改革开放后30年的现代化粮仓建设以及近10年数字化智能化开创等3个阶段。从以“四合一”储粮新技术为主构建现代化粮仓,到以信息技术形成世界上最大的粮食物联网、原创粮堆多场耦合及生物场理论、以粮情云图扫描技术实现储备粮动态监管等,中国储粮的科技进步有目共睹。新时期面临百年未有大变局、中国第二个百年奋斗目标对粮食安全的新要求以及第四次工业革命带来的冲击,粮食科技智慧化的趋势越来越显著。从我国近40多年储粮实践科技成果积累,结合团队对粮堆多场耦合和生物场理论、储备粮云图动态监管、粮食围收储自然区块链5T事联信息化管理以及粮食干燥智能EAT窗口测控方法等的研究,尝试在解构储粮系统三元微结构的基础上,以“一分为二、二分为三、三生变化”为基本思想,以机理、数据等联合驱动为智慧化策略,引入粮仓哲学,以提升对已有科技成果的认知高度、指导新时期储粮科技智慧化的探索,为构建高质量的智慧粮食体系提供支撑。粮仓哲学是对储粮实践情景的深度思考,源于储粮实践,但不限于储粮实践,具有一定的普适性。

Automated phenotyping of Caenorhabditis elegans embryos with a high-throughput-screening microfluidic platform

The nematode Caenorhabditis elegans has been extensively used as a model multicellular organism to study the influence of osmotic stress conditions and the toxicity of chemical compounds on developmental and motility-associated phenotypes.However,the several-day culture of nematodes needed for such studies has caused researchers to explore alternatives.In particular,C.elegans embryos,due to their shorter developmental time and immobile nature,could be exploited for this purpose,although usually their harvesting and handling is tedious.Here,we present a multiplexed,high-throughput and automated embryo phenotyping microfluidic approach to observe C.elegans embryogenesis after the application of different chemical compounds.After performing experiments with up to 800 embryos per chip and up to 12h of time-lapsed imaging per embryo,the individual phenotypic developmental data were collected and analyzed through machine learning and image processing approaches.Our proof-of-concept platform indicates developmental lag and the induction of mitochondrial stress in embryos exposed to high doses(200mM)of glucose and NaCl,while small doses of sucrose and glucose were shown to accelerate development.Overall,our new technique has potential for use in large-scale developmental biology studies and opens new avenues for very rapid high-throughput and high-content screening using C.elegans embryos.

RUBY FLUORESCENCE METHOD OF PRESSURE MEASUREMENT IN DIAMOND CELL UP TO STATIC PRESSURE OF 0.844 Mb

Experiments under high pressure and high temperature have far-reaching effects, theoretically as well as practically, on geosciences, material sciences and physical researches. However, pressure calibration is critical in the field of high pressure technology. We have determined the static pressure up to 0.844 Mb by the ruby

具有精确结构的苯并三氮唑类聚合物受体在全聚合物太阳电池中的应用

以苯并三氮唑(BTz)为稠合中心核单元,通过调控聚合位点设计合成了两个结构精确的聚合物受体PT1-γ和PT1-δ,并研究了聚合位点对聚合物受体的光学性能、电化学性能、载流子迁移率以及全聚合物太阳电池(all-PSCs)性能的影响.研究发现,与PT1-δ相比,PT1-γ具有更窄的光学带隙和更高的电子迁移率.选用PBDB-T作为给体,基于PBDB-T∶PT1-γ的全聚合物太阳电池获得了11.92%的能量转换效率(PCE),高于PBDB-T∶PT1-δ体系的9.68%;另外,其开路电压(VOC)为0.89 V,短路电流密度(JSC)为21.25 mA/cm2,填充因子(FF)为0.63.研究结果表明,聚合位点对基于苯并三氮唑的聚合物受体的光电性能具有显著影响,因而调控单体的聚合位点是开发高性能聚合物受体的有效设计策略.

围垦年限及施氮对滨海湿地CH4好氧氧化过程的影响

本试验选取崇明东滩的光滩湿地和芦苇湿地为对照,比较研究不同围垦年限(19、27、51、86 a)的围垦区稻田耕层土壤CH_(4)好氧氧化的速率和固碳量以及对氮肥的响应特征。结果表明,围垦稻田土壤有机碳(SOC)含量随围垦年限增长而显著增加,而湿地土壤的酸碱度(pH)、硫酸根离子(SO42–)浓度和电导率(EC值)则均随围垦年限增长而呈逐渐下降趋势。围垦稻田的CH_(4)好氧氧化速率存在显著差异,其中围垦27 a稻田最高,为32μg/(g·d),但远低于芦苇湿地(82μg/(g·d))。CH_(4)好氧氧化驱动的固碳净增量(^(13)C-SOC)介于10.3~19.6μmol/g,与CH_(4)氧化速率显著正相关。围垦86 a稻田CH_(4)好氧氧化的固碳效率(^(13)C-SOC净增量/^(13)CH_(4)转化量)为61%,显著高于围垦19 a和27 a稻田。添加3种氮肥(NH_(4)^(+)-N,NO_(3)^(-)-N,Urea)均显著提高了围垦稻田土壤的CH_(4)好氧氧化速率,尤其以NH_(4)^(+)-N最为明显。相反,3种氮肥对围垦稻田土壤的^(13)C-SOC净增量没有明显影响,导致其CH_(4)氧化的固碳效率减小。综上,滨海稻田的CH_(4)好氧氧化速率与围垦年限并无显著正相关,但围垦年限长的稻田中CH_(4)氧化的固碳效率较高;施加氮肥可显著提高围垦稻田土壤的CH_(4)好氧氧化速率。