何以困于长衫:大学生职业角色冲突的归因分析

大学生毕业后找不到心仪工作而呈现的苦闷、迷茫与焦虑等复杂性情绪,是他们共有的职业角色选择与冲突的表现。宏观社会环境所存在的就业结构性矛盾、网络信息传播的放大效应、社会文化普遍性的理想职业期望等,是形成大学生职业角色冲突的外在压力源;具体微观环境中父母对子女的职业角色期望、学校职业生涯规划指导支持不充分、同伴的理想职业追求等,成为大学生职业角色冲突的直接压力源;大学生的职业角色学习是形成职业角色冲突的直接性原因,具体表现为职业角色学习过程会伴随着内在职业角色冲突,职业角色观念决定了职业角色冲突的程度,职业角色冲突影响职业认同结果。

Facile synthesis of the Mn_(3)O_(4)polyhedron grown on N-doped honeycomb carbon as high-performance negative material for lithium-ion batteries

Because of their large volume variation and inferior electrical conductivity,Mn_(3)O_(4)-based oxide anode materials have short cyclic lives and poor rate capability,which obstructs their development.In this study,we successfully prepared a Mn_(3)O_(4)/N-doped honeycomb carbon composite using a smart and facile synthetic method.The Mn_(3)O_(4)nanopolyhedra are grown on N-doped honeycomb carbon,which evidently mitigates the volume change in the charging and discharging processes but also improves the electrochemical reaction kinetics.More importantly,the Mn-O-C bond in the Mn_(3)O_(4)/N-doped honeycomb carbon composite benefits electrochemical reversibility.These features of the Mn_(3)O_(4)/N-doped honeycomb carbon(NHC)composite are responsible for its superior electrochemical performance.When used for Li-ion batteries,the Mn_(3)O_(4)/N-doped honeycomb carbon anode exhibits a high reversible capacity of 598 mAh·g^(−1)after 350 cycles at 1 A·g^(−1).Even at 2 A·g^(−1),the Mn_(3)O_(4)/NHC anode still delivers a high capacity of 472 mAh·g^(−1).This work provides a new prospect for synthesizing and developing manganese-based oxide materials for energy storage.

Safety and Efficacy of Biodegradable Patent Foramen Ovale Occluder in Patients with Migraine:A Clinical Trial

Background:Transcatheter closure of patent foramen ovale(PFO)has been widely accepted as a highly effective way to treat high-risk PFO-related diseases.However,traditional non-degradable occluders made of metal alloys will permanently exist in the body,resulting in thrombosis,valve damage,hemolysis,arrhythmia,or other complications.The biodegradable PFO occluder developed by Shanghai Mallow Medical Instrument Co.,Ltd.,China can be fully absorbed and degrade into nontoxic ingredients,reducing postoperative complications.Objectives:To study the safety and efficacy of biodegradable PFO occluders in treating PFO.Methods:This single-center clinical trial collected 30 patients treated with a biodegradable PFO occluder.The follow-up period lasted 12 months to analyze the echocardiographic characteristics and headache relief through HIT-6 scores.Results:The immediate success rate was 100%,with no intraoperative severe occlusion-related complications.The contrast transcranial Doppler(cTCD)at 12 months showed that all patients’right-to-left shunts(RLS)were grade I or 0 with no serious postoperative complications,indicating the overall success rate was 100%.The biodegradable PFO occluder mostly degraded six months after the occlusion.Conclusion:PFO closure with a Mallow biodegradable occluder is safe and effective and has no severe complications.

鼻中隔偏曲对鼻腔内窥镜下泪囊鼻腔吻合术疗效的影响

目的:探讨鼻中隔偏曲对鼻腔内窥镜下泪囊鼻腔吻合术(EES-DCR)疗效的影响。方法:收集我院2017-06/2019-05收治的慢性泪囊炎患者84例84眼,依据术前鼻内窥镜检查是否有鼻中隔偏曲分组,A组42例42眼无鼻中隔偏曲,B组42例42眼伴有轻、中度鼻中隔偏曲。两组患者均于全身麻醉下行EES-DCR术,对比两组围手术期治疗指标,术后随访6mo评价疗效及鼻腔黏连情况。结果:B组患者手术时间、术中出血量(69.9±13.1min、51.8±16.4mL)均较A组(53.4±11.7min、24.9±12.0mL)多(P<0.05),而住院时间两组无差异(P>0.05)。随访6mo,A组有效率86%,B组有效率71%,两组有效率无差异(P>0.05);A组患者均未发生鼻腔黏连,B组鼻腔黏连发生率为12%,但两组无差异(P>0.05)。结论:慢性泪囊炎合并轻、中度鼻中隔偏曲者,若不伴有鼻腔功能障碍可不在Ⅰ期行鼻中隔偏曲矫正术,单行EES-DCR即可取得较好的效果。

交通风作用下的隧道运营通风研究

公路隧道中,车队行驶产生的交通风可以作为对机械风的补充,对隧道运营期通风节能有重要意义。为了分析交通风对隧道通风的影响,本论文依托太湖水下隧道,建立了1 000 m长度的等比例横截面模型,并对模型进行了独立性验证和有效性验证。基于计算流体力学(CFD)原理,采用动网格技术对不同车型比例构成的车队在隧道行驶产生的交通风进行了数值模拟。结果表明,车队经过检测断面时,产生的交通风速呈现周期性变化,表现为先上升,后下降,最后再回升。当车速为85 km/h,中型车和大型车总占比为50%时,车队平均风速最高可达到2.0 m/s。

Expression of p-STAT3 and vascular endothelial growth factor in MNNG-induced precancerous lesions and gastric tumors in rats

AIM: To investigate the dynamic expression of p-signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in the formation of gastric tumors induced by drinking water containing N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) in Wistar rats. METHODS: One hundred and twenty Wistar rats were randomly divided into two groups (60 in each group): Control group and Model group. The rats in each group were then randomly divided into three groups (20 in each group): C/M15, C/M25 and C/M40 (15, 25 and 40 represent the number of feeding weeks from termination). Rats in the control group received normal drinking water and rats in the model group received drinking water containing 100 μg/mL MNNG. Stomach tissues were collected at the end of the 15th, 25th and 40th week, respectively, for microscopic measurement using hematoxylin and eosin staining. The expression of p-STAT3 and VEGF in different pathological types of gastric tissue, including normal, inflammation, atrophy, hyperplasia and gastric stromal tumor, was observed by immunohistochemistry and Western blot, and the corelation between p-STAT3 and VEGF was analyzed. RESULTS: (1) The expression of p-STAT3 in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor were significantly increased in the model group compared with the control group (2.5 ± 1.0, 2.75 ± 0.36, 6.2 ± 0.45, 5.67 ± 0.55 vs 0.75 ± 0.36, P = 0.026, 0.035, 0.001, 0.002, respectively); the expression of p-STAT3 in tissue with dysplasia was higher than that in samples with gastritis or atrophy (6.2 ± 0.45 vs 2.5 ± 1.0, P = 0.006; 6.2 ± 0.45 vs 2.75 ± 0.36, P = 0.005, respectively); however, the expression of p-STAT3 in gastritis and atrophy was not significantly different (P > 0.05); (2) the expression of VEGF in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor was significantly increased in the model group compared with normal gastric mucosa; and the expression of VEGF in tissue with dysplasia was higher than that in tissue with inflammation and atrophy (10.8 ± 1.96 vs 7.62 ± 0.25, P = 0.029; 10.8 ± 1.96 vs 6.26 ± 0.76, P = 0.033, respectively); similarly, the expression of VEGF in tissue with gastritis and atrophy was not significantly different (P > 0.05); and (3) the expression of VEGF was positively correlated with p-STAT3. CONCLUSION: p-STAT3 plays an important role in gastric cancer formation by regulating the expression of VEGF to promote the progression of gastric tumor from gastritis.

“斜杠青年”职业选择的本体性研究

“斜杠青年”群体的出现是新媒体时代与青年群体特征有机融合的结果或现象,从青年本体性的角度进行解读更有利于理解与把握这一现象。“斜杠青年”主要可以分为迫于经济压力型、爱好特长型、能力所及型三种类别。其职业选择的本体性特征表现为:追求多彩的职业生活、寻求职业潜能的现实化、追寻理想的职业可能性、追求自我价值的社会认同。其成长的宏观职业生态环境的多变性、职业选择价值影响的多元性、成长的微观生态环境的差异性是构成其主体性职业选择的外在原因。“斜杠青年”现象是不以人的意志为转移的客观存在,是现代共享经济时代所必然带来的职场现象。

青年大学生参与网络争议的态度、归因与表现特征——基于《后浪》争议的新媒体时代探究

《后浪》视频引发的争议在青年大学生群体中表现出三种态度:不认同与批判、支持与认同、中立与迷茫。从青年大学生本体的角度来看,基于意见气候感知的自我判断与观点选择、视频蕴含元素的自我解读及焦虑释放、过去经历的带入感与语言不严谨的误读是引发争议的主要原因。理性意见表达与认知性焦虑的结合、过去经历的带入和个体感受的统一、自我价值实现与自我认同需求的结合是青年大学生参与网络争议性事件的表现特征。对这些问题的探究,将有助于加强高校的网络思想政治教育。

Real-Time Black Carbon Emissions from Light-Duty Passenger Vehicles Using a Portable Emissions Measurement System

Black carbon(BC)is considered the second largest anthropogenic climate forcer,but the radiative effects of BC are highly correlated with its combustion sources.On-road vehicles are an important source of anthropogenic BC.However,there are major uncertainties in the estimates of the BC emissions from on-road light-duty passenger vehicles(LDPVs),and results obtained with the portable emissions measurement system(PEMS)method are particularly lacking.We developed a PEMS platform and evaluated the on-road BC emissions from ten in-use LDPVs.We demonstrated that the BC emission factors(EFs)of gasoline direction injection(GDI)engine vehicles range from 1.10 to 1.56 mg.km^(-1),which are higher than the EFs of port fuel injection(PFI)engine vehicles(0.10–0.17 mg.km^(-1))by a factor of 11.The BC emissions during the cold-start phase contributed 2%–33%to the total emissions.A strong correlation(R^(2)=0.70)was observed between the relative BC EFs and average vehicle speed,indicating that traffic congestion alleviation could effectively mitigate BC emissions.Moreover,BC and particle number(PN)emissions were linearly correlated(R^(2)=0.90),and compared to PFI engine vehicles,the instantaneous PN-to-BC emission rates of GDI engine vehicles were less sensitive to vehicle specific power-to-velocity(VSPV)increase in all speed ranges.

Primary balloon angioplasty for chronic occlusion of intracranial internal carotid artery: A case report

Chronic occlusion of large intracranial arteries is the main cause of ischemic stroke in China.Patients with symptomatic intracranial artery occlusion and hemodynamic impairment are at high risk of recurrent stroke.Chronic occlusion of the intracranial segment of the internal carotid artery is a common type of intracranial artery occlusion.Medical management is regarded as the standard treatment for this disease.With the development of endovascular treatment,some patients with chronic cerebral artery occlusion have achieved satisfactory results with endovascular therapy.We reported a patient with symptomatic chronic occlusion of the ophthalmic segment of the internal carotid artery.Simple balloon angioplasty was performed,and the occluded ophthalmic segment of the internal carotid artery was successfully recanalized without perioperative complications.At 4 months followup,the internal carotid artery remained patent and perfusion of the right cerebral hemisphere improved dramatically.In addition,we briefly reviewed the relevant literature.

Structural Dynamics of Amyloid β Peptide Binding to Acetylcholine Receptor and Virtual Screening for Effective Inhibitors

The interaction between Amyloid β(Aβ) peptide and acetylcholine receptor is the key for our understanding of how Aβ fragments block the ion channels within the synapses and thus induce Alzheimer’s disease.Here,molecular docking and molecular dynamics(MD)simulations were performed for the structural dynamics of the docking complex consisting of Aβ and α7-n ACh R(α7 nicotinic acetylcholine receptor),and the inter-molecular interactions between ligand and receptor were revealed.The results show that Aβ_(25-35) is bound toα7-n ACh R through hydrogen bonds and complementary shape,and the Aβ_(25-35) fragments would easily assemble in the ion channel of α7-n ACh R,then block the ion transfer process and induce neuronal apoptosis.The simulated amide-I band of Aβ_(25-35) in the complex is located at 1650.5 cm^(-1),indicating the backbone of Aβ_(25-35) tends to present random coil conformation,which is consistent with the result obtained from cluster analysis.Currently existing drugs were used as templates for virtual screening,eight new drugs were designed and semi-flexible docking was performed for their performance.The results show that,the interactions between new drugs and α7-n ACh R are strong enough to inhibit the aggregation of Aβ_(25-35) fragments in the ion channel,and also be of great potential in the treatment of Alzheimer’s disease.

Design and Experiment of 1LFQ-325 Pneumatic Reversible Plough

A pneumatic reversible plough is developed, which complements to the tractor of 25.7-36.8 kW.The plough adopts the cylinder as reversing mechanism between the right and left plough bodies, and the cylinder can substitute the mechanical reversing mechanism. The pneumatic turnover allows the plough to be operated easily and turned over flexibly. Field experiment results show that indicators of plough performance meet the requirements of the relevant national standards.

Characterization and prediction of tailpipe ammonia emissions from in-use China 5/6 light-duty gasoline vehicles

On-road tailpipe ammonia (NH3) emissions contribute to urban secondary organic aerosol formation and have direct or indirect adverse impacts on the environment and human health. To understand the tailpipe NH3 emission characteristics, we performed comprehensive chassis dynamometer measurements of NH3 emission from two China 5 and two China 6 light-duty gasoline vehicles (LDGVs) equipped with three-way catalytic converters (TWCs). The results showed that the distance-based emission factors (EFs) were 12.72 ± 2.68 and 3.18 ± 1.37 mg/km for China 5 and China 6 LDGVs, respectively. Upgrades in emission standards were associated with a reduction in tailpipe NH3 emission. In addition, high NH3 EFs were observed during the engine warm-up period in cold-start cases owing to the intensive emissions of incomplete combustion products and suitable catalytic temperature in the TWCs. Notably, based on the instantaneous NH3 emission rate, distinct NH3–emitting events were detected under high/extra high velocity or rapid acceleration. Furthermore, NH3 emission rates correlated well with engine speed, vehicle specific power, and modified combustion efficiency, which were more easily accessible. These strong correlations were applied to reproduce NH3 emissions from China 5/6 LDGVs. The predicted NH3 EFs under different dynamometer and real-world cycles agreed well with existing measurement and prediction results, revealing that the NH3 EFs of LDGVs in urban routes were within 8.55–11.62 mg/km. The results presented here substantially contribute to improving the NH3 emission inventory for LDGVs and predicting on-road NH3 emissions in China.

EFFICIENT CONTAMINANT REMOVAL FROM LIQUID DIGESTATE OF PIG MANURE BY CHEMICAL PRECIPITATION AND CO_(2) MINERALIZATION USING ALKALINE ASH

Chemical precipitation is a widely applied approach for a liquid fraction of digestate(LFD)of agricultural waste but its large-scale application requires low-cost and efficient precipitating agents and novel process design.This study evaluated novel approach for the efficient removal of contaminants from the LFD using fly ash-based chemical precipitation,followed by filtration and CO_(2) mineralization.The technical feasibility of this approach was evaluated using pH and electrical conductivity(EC),and removal efficiencies of total phosphorus(TP),chemical oxygen demand(COD)and heavy metals during the treatment.The fly ash used in this study showed a promising performance as a chemical precipitation agent for COD and TP removal from the treated LFD involving complex effects of precipitation and adsorption.CO_(2) bubbling after fly ash-based chemical precipitation provided further COD and TP removal by carbonation reactions between CO_(2) and the excessive alkaline minerals in fly ash.Although addition of fly ash to untreated LFD increased pH from 8.3 to 12.9 and EC from 7.01 to 13.7 mS·cm^(−1),CO_(2) bubbling helped neutralize the treated LFD and reduce the EC,and concentrations of toxic ions by carbonation reactions.The fly ash-based chemical precipitation and CO_(2) mineralization had>93%COD and>98%TP removal efficiencies,and resulted in an EC of<2 mS·cm^(−1) and a neutral pH in the treated LFD,as well as the high purity calcite product.

Role of Soluble ST2 Levels and Beta-Blockers Dosage on Cardiovascular Events of Patients with Unselected ST-Segment Elevation Myocardial Infarction

Background： Serum soluble ST2 （sST2） levels are elevated early after acute myocardial infarction and are related to adverse left ventricular （LV） remodeling and cardiovascular outcomes in ST-segment elevation myocardial infarction （STEMI）. Beta-blockers （BB） have been shown to improve LV remodeling and survival. However, the relationship between sST2, final therapeutic BB dose, and cardiovascular outcomes in STEMI patients remains unknown. Methods： A total of 186 STEMI patients were enrolled at the Wuhan Asia Heart Hospital between January 2015 and June 2015. All patients received standard treatment and were followed up for 1 year. Serum sST2 was measured at baseline. Patients were divided into four groups according to their baseline sST2 values （high 〉56 ng/ml vs. low ≤56 ng/ml） and final therapeutic BB dose （high ≥47.5 mg/d vs. low 〈47.5 mg/d）. Cox regression analyses were performed to determine whether sST2 and BB were independent risk factors for cardiovascular events in STEMI. Results： Baseline sST2 levels were positively correlated with heart rate （r = 0.327, P = 0.002）, Killip class （r = 0.408, P = 0.000）, lg N-terminal prohormone B-type natriuretic peptide （r = 0.467, P = 0.000）, lg troponin I （r = 0.331, P = 0.000）, and lg C-reactive protein （r = 0.307, P = 0.000） and negatively correlated to systolic blood pressure （r = ？0.243, P = 0.009） and LV ejection fraction （r = ？0.402, P = 0.000）. Patients with higher baseline sST2 concentrations who were not titrated to high-dose BB therapy （P 〈 0.0001） had worse outcomes. Baseline high sST2 （hazard ratio [HR]： 2.653; 95% confidence interval [CI]： 1.201–8.929; P = 0.041） and final low BB dosage （HR： 1.904; 95% CI, 1.084–3.053; P = 0.035） were independent predictors of cardiovascular events in STEMI. Conclusions： High baseline sST2 levels and final low BB dosage predicted cardiovascular events in STEMI. Hence, sST2 may be a useful biomarker in cardiac pathophysiology.

Real-world fuel consumption of light-duty passenger vehicles using on-board diagnostic (OBD) systems

An increasing discrepancy between real-world and type-approval fuel consumption for light-duty passenger vehicles(LDPVs)has been reported by several studies.Normally,real-world fuel consumption is measured primarily by a portable emission measurement system.The on-board diagnostic(OBD)approach,which is flexible and offers high-resolution data collection,is a promising fuel consumption monitoring method.Three LDPVs were tested with a laboratory dynamometer based on a type-approval cycle,the New European Driving Cycle(NEDC).Fuel consumption was measured by the OBD and constant-volume sampling system(CVS,a regulatory method)to verify the accuracy of the OBD values.The results of the OBD method and the regulatory carbon balance method exhibited a strong linear correlation(e.g.,R^2=0.906-0.977).Compared with the carbon balance results,the fuel consumption results using the OBD were 7.1%±4.3%lower on average.Furthermore,the real-world fuel consumption of six LDPVs was tested in Beijing using the OBD.The results showed that the normalized NEDC real-world fliel consumption of the tested vehicles was 13%±17%higher than the type-approval-based fuel consumption.Because the OBD values are lower than the actual fuel consumption,using a carbon balance method may result in a larger discrepancy between real-word and type-approval ftiel consumption.By means of the operating mode binning and micro trip methods,a strong relationship(R^2=0.984)was established between the average speed and relative fuel consumption.For congested roads(average vehicle speed less than 25 km/h),the fuel consumption of LDPVs is highly sensitive to changes in average speed.

Mass concentrations and temporal profiles of PM10, PM2.5 and PM1 near major urban roads in Beijing

Mass concentrations of PM10, PM2.5 and PM1 were measured near major roads in Beijing during six periods： summer and winter of 2001, winter of 2007, and periods before, during and after the 2008 Beijing Olympic Games. Since the control efforts for motor vehicles helped offset the increase of emissions from the rapid growth of vehicles, the averaged PM2.5 concentrations at roadsides during the sampling period between 2001 and 2008 fluctuated over a relatively small range. With the implementation of temporary traffic control measures during the Olympics, a clear “V” shaped curve showing the concentrations of particulate matter and other gaseous air pollutants at roadsides over time was identified. The average concentrations of PM10, PM2.5, CO and NO decreased by 31.2%, 46.3%, 32.3% and 35.4%, respectively, from June to August; this was followed by a rebound of all air pollutants in December 2008. Daily PM10 concentrations near major roads exceeded the National Ambient Air Quality Standard （Grade II） for 61.2% of the days in the non-Olympic periods, while only for 12.5% during the Olympics. The mean ratio of PM2.5/PM10 near major roads remained relatively stable at 0.55 （±0.108） on non-Olympic days. The ratio decreased to 0.48 （±0.099） during the Olympics due to a greater decline in fine particles than in coarse-mode PM. The ratios PM1/PM2.5 fluctuated over a wide range and were statistically different from each other during the sampling periods. The average ratios of PM1/PM2.5 on non-Olympic days were 0.71.

The novel SLC40A1(T419I)variant results in a loss-of-function phenotype and may provide insights into the mechanism of large granular lymphocytic leukemia and pure red cell aplasia

Variants in the solute carrier family 40 member 1(SLC40A1)gene are the molecular basis of ferroportin disease,which is an autosomal dominant hereditary hemochromatosis.Here,we present a patient with pure red cell aplasia(PRCA)and large granular lymphocytic leukemia(LGLL)associated with an extremely high levels of serum ferritin and iron overload syndrome.Whole exon sequencing revealed a novel heterozygous variant in SLC40A1(p.T419I),which was found in his daughter as well.A series of functional studies in vitro of the T419I variant in ferroportin were conducted and the results revealed a reduced capacity of iron export from cells without changes in protein localization and its sensitivity to hepcidin.Intracellular iron storage in mutated cells was significantly higher than that of wild-type.These findings suggest that the novel variant p.T419I can cause the classical form of ferroportin disease and an elevated intracellular iron level indicates a potential novel pathogenic mechanism underlying PRCA and LGLL.

Cooperative control of perpendicular magnetic anisotropy via crystal structure and orientation in freestanding SrRuO_(3)membranes

Flexible magnetic materials with robust and controllable perpendicular magnetic anisotropy(PMA)are highly desirable for developing flexible high-performance spintronic devices.However,it is still challenge to fabricate PMA films on polymers directly.Here,we report a facile method for synthesizing single-crystal freestanding SrRuO_(3) membranes with controlled crystal structure and orientation using water-soluble Ca_(3-x)Sr_(x)Al_(2)O_(3)6 sacrificial layers.Through cooperative effect of crystal structure and orientation,flexible membranes reveal highly tunable magnetic anisotropy from in-plane to out-of-plane with a remarkable PMA energy of 7×10^(6) erg·cm^(−3).First-principle calculations reveal that the underlying mechanism of PMA modulation is intimately correlated with structure-controlled Ru 4d-orbital occupation,as well as spin-orbital matrix element differences,dependent on the crystal orientation.In addition,even after 10,000 bending cycles,the PMA keeps stable,indicating a robust magnetism reliability in the prepared films.This work provides a feasible approach to prepare the flexible oxide films with strong and controllable PMA.